A hydraulic control system for an automatic metal chassis flip machine

Abstract

The present invention relates to the field of hydraulic control technology, and specifically discloses a hydraulic control system for an automatic flip machine for a metal chassis. The system includes obtaining the flip angle through a monitoring module, and dynamically adjusting the oil pressure states of the first flip control branch and the second flip control branch by a control unit to achieve matching of the center of gravity trajectory of the workpiece. Among them, the first flip control branch and the second flip control branch respectively contain an electromagnetic reversing valve, a balancing valve and a throttle valve, which can adjust the flow curve according to the flip angle to meet the needs of different strokes. The present invention solves the problems of large braking impact during short-stroke flipping, high energy consumption during long-stroke flipping, and insufficient end positioning accuracy of traditional fixed-parameter hydraulic control systems, and realizes precise matching of load torque and hydraulic drive, which not only ensures fast and smooth braking of short-stroke flips, but also optimizes the energy efficiency and stability of long-stroke flips, and is suitable for the automated flipping needs in high-end material manufacturing processes.

Description

Technical Field

[0001] The invention belongs to the technical field of hydraulic control, and in particular relates to a hydraulic control system of an automatic metal chassis flip machine. Background Art

[0002] In the metal processing and automated manufacturing sectors, hydraulic control technology, as a core power transmission and execution method, is widely used in key equipment such as panel turning machines. With the advancement of high-end material manufacturing processes, the green manufacturing demonstration project for ultra-high-grade grain-oriented silicon steel has placed higher demands on energy efficiency optimization, operational stability, and process precision in the production process. Panel turning machines are the core device for turning and positioning workpieces in such projects, and the performance of their hydraulic control systems directly impacts production efficiency and product quality.

[0003] Existing hydraulic control systems for panel flippers generally employ fixed-parameter designs, relying on solenoid valves to switch oil circuits and drive cylinders to complete workpiece flipping operations. These systems, facing complex operating conditions, lack the ability to flexibly respond to load changes. This can lead to problems such as concentrated impact forces during short-stroke flipping, increased energy loss during long-stroke operations, and insufficient end-positioning accuracy. Furthermore, traditional solutions struggle to balance energy efficiency and system stability, making them unable to meet the comprehensive requirements of high precision, low energy consumption, and sustainable operation required for the green manufacturing of ultra-high-grade grain-oriented silicon steel.

[0004] In order to solve the above technical problems, it is urgent to develop a new hydraulic control system. Summary of the Invention

[0005] The present invention overcomes the deficiencies of the prior art and provides a hydraulic control system for an automatic metal chassis flipping machine.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a hydraulic control system for an automatic metal chassis flip machine, comprising an oil tank, an oil pump, a motor and a directional control valve.

[0007] The oil inlet of the directional control valve is connected to the oil outlet of the oil pump, the first working oil port is connected to the first flap control branch, and the second working oil port is connected to the second flap control branch; the first flap control branch and the second flap control branch are connected in parallel and are independent of each other;

[0008] The first flap control branch includes a first electromagnetic reversing valve, a first balancing valve and a first throttle valve connected in sequence;

[0009] The second flap control branch includes a second electromagnetic reversing valve, a second balancing valve and a second throttle valve connected in sequence;

[0010] The oil outlets of the first flap control branch and the second flap control branch are connected to the first actuating cylinder and the second actuating cylinder respectively;

[0011] The system also includes a monitoring module and a control unit;

[0012] The monitoring module is used to obtain the flip angle;

[0013] The control unit is connected to the monitoring module signal, and is electrically connected to the motor, the first flap control branch, and the second flap control branch; the control unit includes:

[0014] Storage module, pre-stores the center of gravity trajectory parameters of different workpieces;

[0015] The processing module is connected to the storage module via a data bus and is configured to match center of gravity trajectory parameters based on the rollover angle, calculate the hydraulic driving force based on the center of gravity trajectory parameters, and dynamically adjust the pressure setting values ​​of the first balancing valve and the second balancing valve and the flow curves of the first throttle valve and the second throttle valve.

[0016] Furthermore, the pressure setting value adjustment of the first balancing valve and the second balancing valve includes a basic pressure value and an additional pressure compensation value;

[0017] The basic pressure value is determined by the current hydraulic driving force and the effective area of ​​the cylinder;

[0018] The additional pressure compensation value is determined by the rate of change of the hydraulic driving force. When the rate of change increases, the compensation is increased, and when the rate of change decreases, the compensation is reduced.

[0019] Furthermore, the flow curve of the first throttle valve is configured such that when the flip angle is less than a critical angle, the flow rate increases linearly with increasing angle; and when the flip angle is greater than the critical angle, the flow rate decays exponentially with increasing angle.

[0020] Furthermore, the flow curve of the second throttle valve is configured to maintain a constant flow when the flip angle is less than a preset threshold; and when the flip angle is greater than the preset threshold, the flow decreases in a step-by-step manner as the angle increases.

[0021] Furthermore, the oil pump is a variable pump with a maximum flow range of 38-42L / min; the motor is a variable frequency motor with a power range of 17-20kW, connected to the oil pump through a coupling; the directional control valve is a three-position four-way valve with a mid-position unloading function; the system working hydraulic pressure range is 15-18MPa.

[0022] Furthermore, the system includes an electromagnetic relief valve and a set of direct-acting relief valves;

[0023] The oil inlet of the electromagnetic overflow valve is connected to the oil pump, and the oil outlet is connected to the oil tank, and is connected in parallel with the oil tank;

[0024] The oil inlet of the direct-acting relief valve is connected to the high-pressure side of the first flap control branch and the second flap control branch respectively, and the oil outlet is connected to the oil tank respectively.

[0025] Furthermore, the system also includes a water cooler, a heater, and a temperature sensor, all of which are signal-connected to the control unit;

[0026] The cooling circuit of the water cooler is connected to the oil tank through a Y-type water filter;

[0027] The heater is embedded in the side wall of the tank;

[0028] The temperature sensor is connected to the fuel tank and detects the oil temperature inside the fuel tank, and outputs a data signal to the control unit for triggering the start and stop switching of the water cooler and heater.

[0029] Furthermore, the system also includes a filter screen arranged between the oil tank and the oil pump, a high-pressure filter arranged between the oil pump and the directional control valve, and an oil return filter arranged in the oil return line of the oil tank.

[0030] Furthermore, the oil pump is connected to a manual ball valve, and pressure measuring joints are connected in parallel at both ends of the inlet and outlet of the manual ball valve.

[0031] Furthermore, the system also includes a liquid level sensor installed in the oil tank, and the liquid level sensor is connected to the control unit for signal communication.

[0032] The present invention solves the defects existing in the background technology and has the following beneficial effects:

[0033] The present invention establishes a workpiece center of gravity trajectory model, combines the differentiated angle requirements of the first flap's 80-95° short stroke and the second flap's 105-120° long stroke, and dynamically adjusts the balancing valve pressure setting value and the throttle valve flow curve to achieve precise matching of load torque and hydraulic drive, thereby ensuring rapid and smooth braking of the short-stroke flap and optimizing the energy efficiency and stability of the long-stroke flap, thus forming a dual-target collaborative control mechanism.

[0034] Targeting the 80-95° angle characteristics of short-stroke flaps, this invention utilizes a flow control method that transitions from linear acceleration to exponential decay. During the initial stage of turnover, the flow rate increases linearly with the angle to match the load's increasing phase. After exceeding the critical angle, the flow rate rapidly decays exponentially, leveraging gravitational potential energy to achieve natural deceleration. This shortens short-stroke braking time and completely eliminates the water hammer issue associated with traditional fixed-flow valves during emergency stops. Dynamically calculating a safety margin and adaptively adjusting the critical point further ensures safe turnover for different workpieces.

[0035] To address the 105-120° angle characteristics of the long-stroke flap, this invention employs a flow control method that transitions from constant flow to stepped descent. Maintaining a maximum constant flow rate of 38-42 L / min before 100° improves turnover efficiency. After 100°, the flow rate decreases in stages to implement active braking. This improves positioning accuracy at the end of the long stroke, overcoming the high energy consumption associated with traditional constant-speed control. By automatically increasing the flow rate descent slope with angle, braking force is strengthened at 120°, effectively addressing sudden changes in gravitational potential energy.

[0036] This dual-objective control is achieved through deep coupling of the control unit. The present invention synchronizes the center of gravity trajectory parameters based on the flip angle. The short-stroke flap captures greater power during the acceleration phase and suppresses impact through a pressure damping algorithm. The long-stroke flap maintains efficient full-flow operation during the constant-flow phase and achieves precise positioning during the braking phase through adaptive step-down flow reduction. When the load change rate exceeds the 5% per degree threshold, the balancing valve pressure compensation and the throttle valve flow feedforward form a dual buffering mechanism, enabling the synergistic effect of short-stroke gravitational potential energy recovery and long-stroke energy efficiency optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments described in the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive efforts.

[0038] Figure 1 It is a structural diagram of an automatic flip machine with a metal chassis;

[0039] Figure 2 It is a structural diagram of the supporting platform;

[0040] Figure 3 This is a structural diagram of the hydraulic control system of a metal chassis automatic flip machine;

[0041] In the figure: 1, fuel tank; 2, fuel pump; 3, motor; 4, directional control valve; 5, first flap control branch; 51, first electromagnetic reversing valve; 52, first balancing valve; 53, first throttle valve; 54, first actuator cylinder; 6, second flap control branch; 61, second electromagnetic reversing valve; 62, second balancing valve; 63, second throttle valve; 64, second actuator cylinder; 71, electromagnetic relief valve; 72, direct-acting relief valve; 73, water cooler; 74, heater; 75, temperature sensor; 76, oil pump; 77, oil pump; 78, oil pump; 79, oil pump; 80, oil pump; 81, oil pump; 82, oil pump; 83, oil pump; 84, oil pump; 85, oil pump; 86, oil pump; 87, oil pump; 88, oil pump; 89, oil pump; 90, oil pump; 91, oil pump; 92, oil pump; 93, oil pump; 94, oil pump; 95, oil pump; 96, oil pump; 97, oil pump; 98, oil pump; 99, oil pump; 100, oil pump; 101, oil pump; 102, oil pump; 103, oil pump; 104, oil pump; 105, oil pump; 106, oil pump; 107, oil pump; 108, oil pump; 109, oil pump; 110, oil pump; 111, oil pump; 112, oil pump; 113, oil pump; 114, oil pump; 115, oil pump; 116, oil pump; 117, oil pump; 118, oil pump; 119, oil pump; 120, oil pump; 121, oil pump; 122 6. Filter; 77. High-pressure filter; 78. Return oil filter; 79. Manual ball valve; 80. Pressure measuring joint; 81. Liquid level sensor; 100. Support platform; 110. Base; 120. Bearing seat mounting pad; 130. First bearing seat; 140. Second bearing seat; 150. Sensor mounting plate; 160. Support frame; 200. First flap; 210. Spring assembly; 220. First limit member; 300. Second flap; 310. Second limit member; 600. Electric control cabinet. DETAILED DESCRIPTION

[0042] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0043] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0044] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0045] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0046] Exemplary devices:

[0047] like Figure 1 、 2 As shown, a metal chassis automatic flip machine includes a supporting platform 100, a first flip plate 200 and a second flip plate 300 installed on both sides of the supporting platform, a first actuator cylinder 54 powered by the first flip plate 200, and a second actuator cylinder 64 powered by the second flip plate 300.

[0048] The support platform 100 includes a base 110, a bearing seat mounting block 120 mounted on the base 110, a first bearing seat 130 symmetrically positioned on one side of the top of the bearing seat mounting block 120, a second bearing seat 140 symmetrically positioned on the other side of the top of the bearing seat mounting block 120, a sensor mounting plate 150 mounted around the first and second bearing seats 130 and 140, and support frames 160 mounted on both sides of the base 110. The sensor mounting plate 150 is used to mount a sensor; the top of the support frame 160 abuts against the bottom of the first and second flaps 200 and 300 when they are flat.

[0049] The first flap 200 is provided with a first support shaft at its bottom. The first flap 200 is mounted on the first bearing seat 130 via the first support shaft and is rotatably connected to the first bearing seat 130. A spring assembly 210 is provided at the top of the first flap 200 to provide elastic support when the first flap 200 abuts the support frame 160. A first limiter 220 is also provided at the bottom of the first flap 200 to limit the tilting angle of the first flap 200. The contact surface between the first flap 200 and the workpiece to be flipped is also provided with a spacer and a wear-resistant pad.

[0050] The second flap 300 is provided with a second support shaft at the bottom, which is mounted on the second bearing seat 140 through the second support shaft and is rotatably connected to the second bearing seat 140. A second limiter 310 is provided at the bottom of the second flap to limit the flip angle of the second flap 300.

[0051] The first execution oil cylinder 54 is rotatably disposed on one side of the supporting platform 100 , and a retractable first support rod is disposed on the top. The first support rod is rotatably connected to the first flap 200 .

[0052] The second execution oil cylinder 64 is rotatably disposed on the other side of the supporting platform 100 , and a retractable second support rod is disposed on the top. The second support rod is rotatably connected to the second flap 300 .

[0053] like Figure 1 As shown, the panel turning machine is also connected to an electric control cabinet 600 , and the electric control cabinet 600 is integrated with a hydraulic control system for controlling the panel turning machine.

[0054] Exemplary methods:

[0055] A hydraulic control method for an automatic flip machine for a metal chassis is used for controlling the above exemplary device with a control unit, especially providing a method for dynamically adjusting the hydraulic state of the first actuator cylinder 54 and the second actuator cylinder 64. The specific hydraulic control method is shown below.

[0056] As the workpiece rotates with the flipper, the trajectory of its center of gravity in three-dimensional space follows the laws of rigid body kinematics. This trajectory depends not only on the workpiece's geometry and center of mass position, but also on the spindle mounting position and clamping method. Furthermore, during rotational motion, the center of gravity trajectory is a continuous curve determined by the geometry and spindle position. Step S1 decomposes the complex spatial motion into parameterized functions in the horizontal and vertical directions, providing input for mechanical calculations.

[0057] In step S1, the equation ;

[0058] Among them: independent variable Indicates the flip angle (unit: degree), which indicates the angle the flipper rotates from the initial horizontal position (0°), providing a rotation range of 80-95° for the first flip plate 200 and a rotation range of 105-120° for the second flip plate 300. Indicates the horizontal position coordinates of the center of gravity (unit: mm), as function. Indicates the vertical coordinates of the center of gravity (unit: mm), as function. is the initial horizontal position (unit: mm), indicating =0°. If the workpiece is asymmetrical (such as an engine block), Deviating from the center line of the rotating shaft, resulting in initial eccentricity. is the horizontal amplitude (unit: mm), indicating the maximum displacement of the center of gravity in the x-direction during the rollover process. Long workpieces (such as frame rails) have larger values. is the horizontal shape function (dimensionless), describing the center of gravity in the x direction. The mathematical characteristics of the change, optional forms include: linear function (k is the slope, applicable to regular workpieces with uniform center of gravity movement), sine function ( is the angular frequency, is the phase angle, simulating circular trajectory motion) and polynomial function (a, b, c are coefficients, fitting complex nonlinear trajectories). Similarly, is the initial vertical position (unit: mm), indicating =0° is the y coordinate of the center of gravity; is the vertical amplitude (unit: mm), indicating the maximum deviation range of the center of gravity in the y direction; the value is significant for flat workpieces (such as cover plates); is the vertical shape function (dimensionless), describing the center of gravity in the y direction The mathematical characteristics of the change, the optional form is the same .

[0059] Furthermore, methods for obtaining center of gravity trajectory parameters include three-coordinate measurement, dynamic balancing test, and laser tracking dynamic calibration. In the three-coordinate measurement method, a three-coordinate measuring instrument is used to scan the surface point cloud when the workpiece is stationary, and the center of gravity position is calculated using CAD software. In the dynamic balancing test, the workpiece is mounted on a rotating platform, counterweights are added at different angles until the torque is balanced, and the center of gravity trajectory is inferred. In the laser tracking dynamic calibration method, a laser tracker is used to record the movement of the marker points in real time during the flipping process, and the center of gravity trajectory is calculated using the rigid body transformation matrix.

[0060] The oil circuit is precisely controlled by center of gravity trajectory modeling, for example: When it is greater than 0, it means that the workpiece is horizontally eccentric and a larger initial thrust is required during the startup phase. When there is a maximum value near 90°, it indicates that the load torque at this position is the largest and the system pressure needs to be increased in advance; the trajectory curvature change point ( The mutation point) corresponds to the key point for adjusting the hydraulic parameters.

[0061] Step S2 calculates the rotational torque generated by gravity on the axis of rotation using the equation .

[0062] in: is the rotational torque generated by gravity on the axis of rotation (unit: N·m), as function. is the weight of the workpiece (unit: N), calculated using the formula G=m⋅g (m is the mass of the workpiece, unit: kg; g is the acceleration due to gravity, which is 9.8 m / s²). is the vertical position of the center of gravity (unit: mm), is the horizontal position of the center of gravity (unit: mm). is the axis inclination angle (unit: degree), which represents the angle between the axis and the horizontal plane. 、 is a trigonometric function term (dimensionless) used for coordinate rotation correction.

[0063] The load moment is essentially the rotational effect of gravity on the shaft, and its magnitude depends on the gravity, the effective lever ( , representing the vertical distance from the line of action of gravity to the axis of rotation) and the inclination angle of the axis of rotation ( ,when ≠0) The axis is not installed horizontally and coordinate rotation correction is required. When the center of gravity-axis connection line is perpendicular to the direction of gravity, the lever arm is maximum and the torque reaches its peak. For most workpieces, this occurs when It is in the range of 70-100°.

[0064] Furthermore, the first-order derivative represents the rate of change of torque, When it is greater than 0, it is the load increasing stage and the hydraulic thrust needs to be increased; During the load reduction phase, gravity can be used to assist the movement.

[0065] Furthermore, the second-order derivative Reflects the acceleration of torque change. A positive value indicates that the load is increasing at an accelerated rate and the flow rate needs to be increased preventively. A negative value indicates that the load is increasing at a slower rate and the hydraulic power can be reduced.

[0066] Step S3 determines the thrust that the cylinder needs to output using the equation .

[0067] in: is the thrust that the cylinder needs to output (unit: N), as function. is the rotational torque (unit: N·m). is the lever arm function (unit: m), which indicates the real-time distance between the cylinder hinge and the axis of rotation. In the four-bar linkage, It usually changes nonlinearly and is expressed as , are the hinge coordinates, is the axis coordinate. Is the angle function (unit: degree), which represents the real-time angle between the cylinder axis and the normal direction of the lever arm; it affects the thrust transmission efficiency ,when When the angle is greater than 30°, the efficiency drops significantly and additional thrust compensation is required. Friction compensation (unit: N), the additional force required to overcome mechanical friction, take the empirical value , is the maximum value of the ratio of moment to lever arm (unit: N).

[0068] Based on the above, the thrust change rate (core dynamic parameter) can be obtained .in: It is the rate of change of thrust with the flip angle (unit: N / degree), reflecting the dynamic characteristics of the load. is the rate of change of torque (unit: N·m / degree), indicating right The first derivative of When it is greater than 0, it is the load increasing stage and the hydraulic thrust needs to be increased. is the rate of change of the lever arm (unit: m / degree), indicating right The first-order derivative of ; reflects the kinematic influence of the mechanical structure. is the angle change rate (unit: degree / degree), indicating right The first derivative of ; significant when the hinge structure is special.

[0069] Furthermore, Contributes to the change in torque, is the main term, and determines the overall trend; , contributes to the change of the lever arm and is significant when the mechanical structure changes; Contributes to the change in angle, which is significant when the hinge structure is special.

[0070] thus, Determine the response of the hydraulic system: When the threshold parameter ( is the maximum thrust of the cylinder, unit: N), pressure feedforward control needs to be enabled; when the threshold parameter When the flow rate is constant, constant flow control can be used.

[0071] Step S4 converts the mechanical requirements into hydraulic system control parameters.

[0072] Pressure-based control .

[0073] in: is the system pressure setting value (unit: MPa), as function. is the cylinder thrust (unit: N). is the effective area of ​​the oil cylinder (unit: m²), and the calculation formula is (D is the cylinder diameter, unit: mm; d is the rod diameter, unit: mm). is the proportional gain coefficient (unit: MPa·s / N), which is used for the lead control of the differential term; it is adjusted according to the system inertia (0.8-1.2 for large inertia systems and 0.3-0.6 for small inertia systems). is the thrust change rate (unit: N / degree). is the integral gain coefficient (unit: MPa·s² / N), which is used to compensate for the steady-state error of the integral term. is the thrust error integral term (unit: N·degree), where is the thrust error (unit: N), which is defined as the deviation between the actual thrust and the target thrust; is the integral variable (unit: degree), which represents the infinitesimal flip angle.

[0074] The static pressure component includes the basic term , directly balance the current load.

[0075] The dynamic compensation component includes the differential term ( ) and the integral term ( ). Differential term ( ) provides advanced control to suppress system oscillation; when When it is greater than 0, pressure compensation is added (to prevent stall); when When it is less than 0, the pressure compensation is reduced (to prevent overshoot). ) Eliminate steady-state errors and compensate for model deviations, and are particularly suitable for overcoming the effects of static friction and leakage.

[0076] And, when The pressure damping algorithm is activated when: , is the damping gain coefficient, unit: MPa·s² / N; is the damping pressure, in MPa.

[0077] Based on flow control, the following formula is used for calculation: .

[0078] in: is the flow rate setting value (unit: L / min), as function. is the effective area of ​​the oil cylinder (unit: m²). is the speed curve required by the process (unit: mm / s), as function. is the speed compensation gain coefficient (dimensionless), used to smooth the speed deviation. is the hyperbolic tangent function (dimensionless), where is the speed deviation (unit: mm / s), defined as the deviation between the actual speed and the target speed; The maximum allowable speed (unit: mm / s), which is the system setting value. is the load mutation suppression gain coefficient (unit: L min -1 ·s² / N), take 0.01-0.05 m³ / (N·s²) (for large inertia systems, take the upper limit). It is the absolute value of the thrust change acceleration (unit: N / degree²), reflecting the intensity of the load mutation.

[0079] Base flow item, The speed curve required by the process; is the speed compensation function. When the actual speed deviation When it is greater than 10%, the flow rate is smoothly adjusted through the tanh function.

[0080] Load mutation suppression term, The acceleration of thrust change reflects the intensity of load mutation; through the gain Pre-increase the flow rate before the load changes suddenly to absorb the impact energy.

[0081] Flow control must meet both speed and stability requirements. The second-order derivative detects the rapidity of load changes and provides additional flow buffering during sudden acceleration changes.

[0082] Step S5 performs angle interval differentiation.

[0083] For the first flap 200 target angle travel 80-95°, critical point ,in is the critical angle (unit: degree), the angle at which the acceleration phase ends and the deceleration phase begins; is the safety margin (unit: degree) to ensure braking safety. The calculation formula is: , is the system braking time constant (unit: seconds, determined by the inertia of the hydraulic system), is the maximum angular velocity (unit: degree / second, indicating the maximum rotation rate of the flip machine), is a proportionality constant (dimensionless, used to relate time and angle units, defaults to 1).

[0084] The flow control function is , change 0- Defined as the acceleration stage, the flow rate increases linearly, and the matching torque rises ( );Will - Defined as the deceleration stage, the flow rate decays exponentially and decelerates naturally using gravitational potential energy. It is the short-stroke flow setting value (unit: L / min), which is dedicated to short-stroke flaps. is the minimum flow rate (unit: L / min), the system adjustable lower limit; is the linear increase coefficient (unit: L / (min·degree)), which controls the flow slope of the acceleration section; is the maximum flow rate (unit: L / min); is the exponential attenuation coefficient (unit: 1 / degree), and the calculation formula is , ensure that the angle travel The flow rate drops to a safe value.

[0085] For the second flap 300 target angle travel is 105-120°, where the critical point is 100°, and the flow control function is .in, It is the long-stroke flow setting value (unit: L / min), dedicated to long-stroke flaps. is a constant flow rate (unit: L / min), taking the maximum flow range of the oil pump; is the descending slope (unit: L / (min·degree)), which controls the flow rate deceleration rate in the braking section. , is the initial flow rate decline slope (unit: L / (min·degree)), =105°. Define 0-100° as the constant speed section, maintain maximum efficiency reversal, and apply to the torque stable area; define 100- is defined as the braking section, where the flow rate decreases in steps and active braking is used to resist the gravitational potential energy.

[0086] The exemplary method described above is based on the fusion of rigid-body dynamics principles and the transfer characteristics of hydraulic systems. In step S1, a parametric model of the spatial trajectory of the workpiece's center of gravity is established, decomposing the complex spatial rigid-body motion into quantifiable geometric characteristic parameters, including initial eccentricity, motion amplitude, and trajectory morphology function. This model is validated using three-dimensional coordinate measurement and laser dynamic calibration technology. Its selection of functions covers the center of gravity distribution patterns of most metal chassis workpieces, providing precise input for subsequent mechanical calculations.

[0087] The mechanical conversion process from steps S2 to S3 is based on the principle of virtual work. By analyzing the changing characteristics of the moment arm due to gravity on the rotating shaft, the nonlinear variation of the load torque with the tilt angle is calculated. The moment arm function and transmission efficiency factor of the cylinder articulation mechanism are then incorporated to convert the load torque into the real-time driving force required by the hydraulic actuator. This conversion process fully considers the kinematic constraints of the mechanical structure and friction loss compensation, significantly improving the dynamic matching accuracy between the hydraulic driving force and the load torque.

[0088] In the hydraulic parameter mapping mechanism of step S4, the driving force change rate is decomposed into a dual-channel regulation of pressure and flow control terms. Pressure control incorporates a dynamic compensation mechanism, suppressing system oscillations through a leading differential term and eliminating steady-state errors caused by static friction through an integral term. Flow control uses a second-order derivative to detect the intensity of sudden load changes and pre-increases flow to provide a buffer against sudden acceleration changes. This dual-channel decoupling control strategy ensures stable pressure even under highly nonlinear load conditions.

[0089] The differentiated control strategy of step S5 is derived from the quantitative analysis of the energy conversion characteristics of the two types of strokes: the short stroke range of 80-95° usually contains the load torque extreme point, and the torque change rate turns from positive to negative near 85°, and the system kinetic energy reaches its peak; in the long stroke range of 105-120°, the center of gravity of the workpiece passes the highest point of the rotation axis, and the gravitational potential energy is converted into acceleration kinetic energy.

[0090] Within the short-stroke 80-95° angle range, the rate of torque change reverses when the rotation exceeds 85°, at which point the system's accumulated rotational kinetic energy reaches its peak. Exponential flow decay mode uses a specific time constant to ensure that the flow rate decays substantially within a 5-degree rotation angle, rapidly dissipating kinetic energy through hydraulic damping. This control method significantly shortens braking distances compared to traditional on-off valve braking and eliminates water hammer caused by the sudden loss of kinetic energy.

[0091] Within the long travel range of 105-120°, when the tilt angle exceeds 100°, the workpiece's center of gravity shifts from a high to a low position relative to the axis of rotation, converting gravitational potential energy into downward acceleration. A stepped flow reduction strategy reduces flow in stages (15% every 5 degrees), actively increasing hydraulic resistance while maintaining smooth deceleration. This converts gravitational potential energy into system pressure energy for recycling, while also precisely controlling the deceleration process to significantly improve end-of-line positioning accuracy and reduce overall stroke energy consumption, fully meeting the requirements of green manufacturing projects.

[0092] Example systems:

[0093] like Figure 3 As shown, a hydraulic control system for an automatic metal chassis flip machine provides power for an exemplary device based on the above exemplary method, including an oil tank 1, an oil pump 2, a motor 3 and a directional control valve 4. Among them:

[0094] The oil inlet of the directional control valve 4 is connected to the oil outlet of the oil pump 2, the first working oil port is connected to the first flap control branch 5, and the second working oil port is connected to the second flap control branch 6; the first flap control branch 5 and the second flap control branch 6 are connected in parallel and are independent of each other;

[0095] The first flap control branch 5 includes a first electromagnetic reversing valve 51, a first balancing valve 52 and a first throttle valve 53 connected in sequence;

[0096] The second flap control branch 6 includes a second electromagnetic reversing valve 61, a second balancing valve 62 and a second throttle valve 63 connected in sequence;

[0097] The oil outlets of the first flap control branch 5 and the second flap control branch 6 are connected to the first actuating cylinder 54 and the second actuating cylinder 64 respectively;

[0098] Also includes a monitoring module and a control unit;

[0099] The monitoring module includes a first sensor mounted on the sensor mounting plate 150 for obtaining the flip angles of the first flap 200 and the second flap 300; and a second sensor mounted on the first flap control branch 5 and the second flap control branch 6 for obtaining the oil pressure status of the first flap control branch 5 and the second flap control branch 6;

[0100] The control unit is connected to the monitoring module signal and is electrically connected to the motor 3, the first flap control branch 5 and the second flap control branch 6; the control unit includes:

[0101] Storage module, pre-stores the center of gravity trajectory parameters of different workpieces;

[0102] The processing module is connected to the storage module via a data bus and is configured to match the center of gravity trajectory parameters based on the flip angle, calculate the hydraulic driving force based on the center of gravity trajectory parameters, and dynamically adjust the pressure setting values ​​of the first balancing valve 52 and the second balancing valve 62 and the flow curves of the first throttle valve 53 and the second throttle valve 63.

[0103] Furthermore, the pressure setting value adjustment of the first balancing valve 52 and the second balancing valve 62 includes a basic pressure value and an additional pressure compensation value;

[0104] The basic pressure value is determined by the current hydraulic driving force and the effective area of ​​the cylinder;

[0105] The additional pressure compensation value is determined by the rate of change of the hydraulic driving force. When the rate of change increases, the compensation is increased, and when the rate of change decreases, the compensation is reduced.

[0106] Furthermore, the flow curve of the first throttle valve 53 is configured such that when the flip angle is less than the critical angle, the flow rate increases linearly with increasing angle; when the flip angle is greater than the critical angle, the flow rate decays exponentially with increasing angle;

[0107] Furthermore, the flow curve of the second throttle valve 63 is configured to maintain a constant flow when the flip angle is less than a preset threshold; and when the flip angle is greater than the preset threshold, the flow decreases in a step-by-step manner as the angle increases.

[0108] Furthermore, the oil pump 2 is a variable pump with a maximum flow range of 38-42L / min; the motor 3 is a variable frequency motor with a power range of 17-20kW, connected to the oil pump through a coupling; the directional control valve 4 is a three-position four-way valve with a neutral unloading function; the system working hydraulic pressure range is 15-18MPa.

[0109] Furthermore, the system also includes an electromagnetic relief valve 71 and a set of direct-acting relief valves 72;

[0110] The oil inlet of the electromagnetic overflow valve 71 is connected to the oil pump 2, and the oil outlet is connected to the oil tank 1, and is connected in parallel with the oil tank 1;

[0111] The oil inlet of the direct-acting relief valve 72 is connected to the high-pressure side of the first flap control branch 5 and the second flap control branch 6 respectively, and the oil outlet is connected to the oil tank 1 respectively.

[0112] Furthermore, the system also includes a water cooler 73, a heater 74 and a temperature sensor 75, all of which are signal-connected to the control unit;

[0113] The cooling circuit of the water cooler 73 is connected to the oil tank 1 via a Y-type water filter;

[0114] The heater 74 is embedded in the side wall of the fuel tank 1;

[0115] The temperature sensor 75 is connected to the oil tank 1 and detects the oil temperature inside the oil tank 1 , and outputs a data signal to the control unit for triggering the start and stop switching of the water cooler 73 and the heater 74 .

[0116] Furthermore, the system also includes a filter 76 arranged between the oil tank 1 and the oil pump 2, a high-pressure filter 77 arranged between the oil pump 2 and the directional control valve 4, and a return oil filter 78 arranged in the oil return line of the oil tank 1.

[0117] Furthermore, the oil pump 2 is connected to a manual ball valve 79 , and pressure measuring joints 80 are connected in parallel at both ends of the inlet and outlet of the manual ball valve 79 .

[0118] Furthermore, the system also includes a liquid level sensor 81 installed in the oil tank 1, and the liquid level sensor 81 is connected to the control unit for signal communication.

[0119] In a specific embodiment, the system pressure is 16 MPa, the system flow is 40 L / min, the average speed of the first actuator cylinder 54 and the second actuator cylinder 64 is 186.795 mm / s, and the stroke of a single cylinder is 900 mm; the system needs to perform two active braking and flow adjustments in the transition stage between short stroke and long stroke, with a total dead time of 15 seconds; a single complete flipping process takes about 100 seconds.

[0120] The above description is based on the ideal embodiment of the present invention. Based on the above description, relevant personnel can make various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the content of the specification and must be determined according to the scope of the claims.

Claims

1. A hydraulic control system for an automatic metal chassis flipping machine, used to provide power for the flipping machine, comprising an oil tank (1), an oil pump (2), a motor (3) and a directional control valve (4), characterized in that: The oil inlet of the directional control valve (4) is connected to the oil outlet of the oil pump (2), the first working oil port is connected to the first flap control branch (5), and the second working oil port is connected to the second flap control branch (6); the first flap control branch (5) and the second flap control branch (6) are connected in parallel and are independent of each other; The first flap control branch (5) comprises a first electromagnetic reversing valve (51), a first balancing valve (52), and a first throttle valve (53) connected in sequence; The second flap control branch (6) comprises a second electromagnetic reversing valve (61), a second balancing valve (62), and a second throttle valve (63) connected in sequence; The oil outlets of the first flap control branch (5) and the second flap control branch (6) are connected to the first actuating oil cylinder (54) and the second actuating oil cylinder (64) respectively; Also includes a monitoring module and a control unit; The monitoring module is used to obtain the flip angle; The control unit is connected to the monitoring module signal and is electrically connected to the motor (3), the first flap control branch (5) and the second flap control branch (6); the control unit includes: Storage module, pre-stores the center of gravity trajectory parameters of different workpieces; The processing module is connected to the storage module via a data bus and is configured to match the center of gravity trajectory parameters based on the rollover angle, calculate the hydraulic driving force based on the center of gravity trajectory parameters, and dynamically adjust the pressure setting values ​​of the first balancing valve (52) and the second balancing valve (62) and the flow curves of the first throttle valve (53) and the second throttle valve (63); The flow curve of the first throttle valve (53) is configured such that when the flip angle is less than a critical angle, the flow rate increases linearly as the angle increases; when the flip angle is greater than the critical angle, the flow rate decays exponentially as the angle increases; The flow curve of the second throttle valve (63) is configured to maintain a constant flow rate when the flip angle is less than a preset threshold; and when the flip angle is greater than the preset threshold, the flow rate decreases in a step-like manner as the angle increases.

2. The hydraulic control system according to claim 1, characterized in that: The pressure setting value adjustment of the first balancing valve (52) and the second balancing valve (62) includes a basic pressure value and an additional pressure compensation value; The basic pressure value is determined by the current hydraulic driving force and the effective area of ​​the cylinder; The additional pressure compensation value is determined by the rate of change of the hydraulic driving force. When the rate of change increases, the compensation is increased, and when the rate of change decreases, the compensation is reduced.

3. The hydraulic control system according to claim 1, characterized in that: The oil pump (2) is a variable displacement pump with a maximum flow range of 38-42 L / min; The motor (3) is a variable frequency motor with a power range of 17-20kW and is connected to the oil pump via a coupling; The directional control valve (4) is a three-position four-way valve with a neutral unloading function; The system's working hydraulic pressure range is 15-18MPa.

4. The hydraulic control system according to claim 1, characterized in that: It also includes an electromagnetic overflow valve (71) and a set of direct-acting overflow valves (72); The oil inlet of the electromagnetic overflow valve (71) is connected to the oil pump (2), and the oil outlet is connected to the oil tank (1), and is connected in parallel with the oil tank (1); The oil inlet of the direct-acting relief valve (72) is respectively connected to the high-pressure side of the first flap control branch (5) and the second flap control branch (6), and the oil outlet is respectively connected to the oil tank (1).

5. The hydraulic control system according to claim 1, characterized in that: It also includes a water cooler (73), a heater (74) and a temperature sensor (75) all of which are connected to the control unit signal; The cooling circuit of the water cooler (73) is connected to the oil tank (1) via a Y-type water filter; The heater (74) is embedded in the side wall of the oil tank (1); The temperature sensor (75) is connected to the oil tank (1) and detects the oil temperature inside the oil tank (1), and outputs a data signal to the control unit for triggering the start and stop switching of the water cooler (73) and the heater (74).

6. The hydraulic control system according to claim 1, characterized in that: It also includes a filter screen (76) arranged between the oil tank (1) and the oil pump (2), a high-pressure filter (77) arranged between the oil pump (2) and the directional control valve (4), and an oil return filter (78) arranged in the oil return line of the oil tank (1).

7. The hydraulic control system according to claim 1, characterized in that: The oil pump (2) is connected to a manual ball valve (79), and the inlet and outlet ends of the manual ball valve (79) are connected in parallel to pressure measuring joints (80).

8. The hydraulic control system according to claim 1, characterized in that: It also includes a liquid level sensor (81) installed in the oil tank (1), and the liquid level sensor (81) is connected to the control unit signal.

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