Safety protection method of hydraulic lifting platform and hydraulic lifting platform

Abstract

The application provides a safety protection method and a hydraulic lifting platform, and relates to the technical field of safety protection of the hydraulic lifting platform. The scheme acquires the running state parameters of the hydraulic lifting platform in real time, comprehensively determines and controls the electromagnetic reversing valve, and makes the hydraulic lifting platform enter the first-level safety protection. After the first-level safety protection is started, the hydraulic pressure change is continuously detected, it is judged whether the first-level safety protection is abnormal, and the second-level safety protection state is identified in combination with the platform inclination and the platform descending speed when the abnormality occurs. The scheme realizes the hierarchical safety determination and continuous control response, and can improve the fault identification accuracy and the safety and reliability of the hydraulic lifting platform.

Description

Technical Field

[0001] This application relates to the field of safety protection technology for hydraulic lifting platforms, and in particular to a safety protection method for a hydraulic lifting platform and a hydraulic lifting platform. Background Technology

[0002] Heavy-duty lifting platforms are typically used in industrial manufacturing, logistics warehousing, and construction scenarios to achieve lifting operations using a combination of hydraulic drive and electronic control monitoring for safety protection.

[0003] However, existing protection solutions mostly rely on single or dual-layer protection architectures. Anomaly detection is often based on a single parameter or independent alarm signal. The monitoring information and the actuator are not linked enough, making it difficult to accurately identify and quickly handle complex faults such as tilting, pressure fluctuations and abnormal speeds. Furthermore, under high-frequency load impacts, single-point failures are prone to occur, leading to a decrease in protection reliability. Summary of the Invention

[0004] In view of the above problems, this application provides a safety protection method for a hydraulic lifting platform and a hydraulic lifting platform, which can improve the ability to identify complex faults and the reliability of protection against abnormal working conditions.

[0005] To achieve the above objectives, the embodiments of this application provide the following technical solutions:

[0006] In a first aspect, embodiments of this application provide a safety protection method for a hydraulic lifting platform, applied to a hydraulic lifting platform, the method comprising:

[0007] The operating status parameters of the hydraulic lifting platform are obtained, including the first hydraulic pressure, the first platform tilt angle, and the first platform descent speed.

[0008] Based on the first hydraulic pressure, the first platform tilt angle, and the first platform descent speed, the opening and closing of the electromagnetic reversing valve in the hydraulic lifting platform is controlled to determine whether the hydraulic lifting platform enters the first-level safety protection state.

[0009] When the hydraulic lifting platform enters the first-level safety protection state, the second hydraulic pressure is obtained, and based on the first hydraulic pressure and the second hydraulic pressure, it is determined whether the first-level safety protection state is abnormal.

[0010] If the first-level safety protection status is determined to be abnormal, the tilt angle of the second platform and the descent speed of the second platform are obtained. Based on the tilt angle of the second platform and the descent speed of the second platform, the second-level safety protection status of the hydraulic lifting platform is determined.

[0011] In one possible implementation, controlling the opening and closing of the electromagnetic directional valve in the hydraulic lifting platform based on the first hydraulic pressure, the first platform tilt angle, and the first platform descent speed to determine whether the hydraulic lifting platform enters a first-level safety protection state includes:

[0012] If at least one of the parameters of the first hydraulic pressure, the first platform tilt angle, and the first platform descent speed reaches the corresponding preset threshold, the electromagnetic reversing valve is controlled to disconnect, and the hydraulic lifting platform is determined to enter the first-level safety protection state.

[0013] If none of the first hydraulic pressure, the first platform tilt angle, or the first platform descent speed reaches the corresponding preset threshold, the electromagnetic reversing valve is closed to determine that the hydraulic lifting platform has not entered the first-level safety protection state.

[0014] In one possible implementation, obtaining the second hydraulic pressure and determining whether the primary safety protection state is abnormal based on the first hydraulic pressure and the second hydraulic pressure includes:

[0015] After the hydraulic lifting platform has entered the first-level safety protection state for a preset time, the second hydraulic pressure is obtained;

[0016] Calculate the pressure change between the first hydraulic pressure and the second hydraulic pressure;

[0017] If the pressure change is greater than the preset pressure change threshold, then the first-level safety protection status is determined to be abnormal.

[0018] If the pressure change is less than or equal to the preset pressure change threshold, then the first-level safety protection status is determined to be normal.

[0019] In one possible implementation, determining the secondary safety protection state of the hydraulic lifting platform based on the tilt angle and descent speed of the second platform includes:

[0020] If the tilt angle of the second platform is less than the preset tilt angle and the descent speed of the second platform is less than the preset speed, then the secondary protection status is determined to be normal.

[0021] If the tilt angle of the second platform is greater than or equal to the preset tilt angle, or the descent speed of the second platform is greater than or equal to the preset speed, then the secondary protection status is determined to be abnormal.

[0022] In one possible implementation, the method further includes:

[0023] If the hydraulic lifting platform moves to a preset limit position when the level 2 safety protection status is determined to be abnormal, then the hydraulic lifting platform is determined to enter the level 3 safety protection status.

[0024] Secondly, this application provides a hydraulic lifting platform, which includes a platform body, a hydraulic cylinder, a solenoid directional valve, a hydraulic lock, a speed limiting valve, and a controller.

[0025] The hydraulic cylinder is connected to the platform body and is used to drive the platform body to perform lifting and lowering movements;

[0026] The electromagnetic directional valve is connected to the hydraulic cylinder and is used to control the on / off state of the hydraulic oil circuit corresponding to the hydraulic cylinder.

[0027] The hydraulic lock is installed in the hydraulic circuit corresponding to the hydraulic cylinder and is used to maintain the state of the hydraulic oil in the hydraulic cylinder when the solenoid directional valve disconnects the hydraulic circuit, thereby restricting the extension and retraction of the hydraulic cylinder.

[0028] The speed limiting valve is installed in the return oil line of the hydraulic cylinder to limit the descent speed of the hydraulic cylinder;

[0029] The controller is connected to the electromagnetic directional valve and is used to execute the safety protection method of the hydraulic lifting platform described in any of the above claims.

[0030] In one possible implementation, the hydraulic lifting platform further includes: a pressure sensor, a tilt sensor, and a speed sensor;

[0031] The pressure sensor is installed in the hydraulic circuit corresponding to the hydraulic cylinder to detect the hydraulic pressure of the hydraulic cylinder;

[0032] The tilt sensor is installed on the platform body and is used to detect the tilt angle of the platform body;

[0033] The speed sensor is used to detect the descent speed of the platform body;

[0034] The pressure sensor, the tilt sensor, and the speed sensor are each connected to the controller.

[0035] In one possible implementation, two of each of the hydraulic cylinder, solenoid directional valve, hydraulic lock, and speed limiting valve are provided.

[0036] The two hydraulic cylinders are respectively located on both sides of the platform body, each with an independent hydraulic circuit;

[0037] Each of the hydraulic cylinders is respectively provided with an electromagnetic directional valve, a hydraulic lock, and a speed limiting valve.

[0038] In one possible implementation, the hydraulic lifting platform further includes: a limit stop;

[0039] The limiting block is set at the extreme position of the platform body's movement and is used to mechanically block the platform body when both the primary and secondary safety protection states fail, thereby restricting the platform body from continuing to move.

[0040] In one possible implementation, the hydraulic lifting platform further includes: an upper limit switch and a lower limit switch;

[0041] The upper limit switch and the lower limit switch are respectively set at the motion limit positions corresponding to the platform body;

[0042] The controller is connected to the upper limit switch and the lower limit switch respectively, and is used to detect that the hydraulic lifting platform has run to a preset limit position according to the upper limit switch and the lower limit switch, and trigger the three-level safety protection.

[0043] The safety protection method for the hydraulic lifting platform provided in this application embodiment, and the hydraulic lifting platform itself, obtain the operating status parameters of the hydraulic lifting platform and combine them with the first hydraulic pressure, the first platform tilt angle, and the first platform descent speed to control the opening and closing of the solenoid directional valve to determine whether to enter the first-level safety protection state. This can link the platform pressure, attitude, and motion state with the actuator to achieve timely response to abnormal working conditions. Furthermore, after entering the first-level safety protection state, it is further determined whether the first-level safety protection state is abnormal based on the first hydraulic pressure and the second hydraulic pressure. If an abnormality is determined, the second-level safety protection state is determined by combining the second platform tilt angle and the second platform descent speed. This can re-verify the first-level protection result and complete the graded protection judgment, thereby improving the safety protection response reliability and fault adaptability of the hydraulic lifting platform.

[0044] In addition to the technical problems solved by the embodiments of this application, the technical features constituting the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions described above, the safety protection method of the hydraulic lifting platform provided by the embodiments of this application, as well as other technical problems that the hydraulic lifting platform can solve, other technical features included in the technical solutions, and the beneficial effects brought about by these technical features, will be further explained in detail in the specific implementation. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 Flowchart of the safety protection method for the hydraulic lifting platform provided in this application Figure 1 ;

[0047] Figure 2 Flowchart of the safety protection method for the hydraulic lifting platform provided in this application Figure 2 ;

[0048] Figure 3 This is a schematic diagram of the structure of the hydraulic lifting platform provided in the embodiments of this application.

[0049] Explanation of reference numerals in the attached figures:

[0050] 1-Platform body; 2-Hydraulic cylinder; 3-Solenoid directional valve; 4-Hydraulic lock; 5-Speed ​​limit valve; 6-Pressure sensor; 7-Tilt sensor; 8-Speed ​​sensor; 9-Limit stop; 10-Upper limit switch; 11-Lower limit switch. Detailed Implementation

[0051] Hydraulic lifting platform safety protection technology involves the field of industrial equipment control and operational safety, and is mainly used in heavy-duty lifting operations in industrial manufacturing, logistics warehousing and construction sites.

[0052] Existing heavy-duty lifting platforms mostly use hydraulic systems in conjunction with electromagnetic directional valves, pressure detection elements, and limit detection elements to achieve basic safety control. Their operation typically involves collecting individual status information during platform operation and outputting alarms or shutdown commands when abnormal pressure, stroke completion, or posture deviation is detected. While some devices have added tilt angle or speed detection functions, most signals are processed independently, remaining largely at the alarm level and lacking close linkage with the actuators.

[0053] The above methods can provide basic protection under normal operating conditions. However, under conditions of high-frequency lifting, heavy-load impact, pipeline fluctuations, or localized failures, judging a single parameter can easily miss complex faults, and independent alarms are difficult to translate into effective control actions in a timely manner. When the platform simultaneously experiences abnormal pressure, attitude deviation, and changes in descent speed, the system may fail to accurately identify the fault level, and the control timing of the electromagnetic reversing valve may be delayed, resulting in a lack of subsequent judgment on the continued expansion of the abnormality after the first-level protection fails. This can easily lead to problems such as interruption of the protection link, insufficient fault adaptability, and an increased risk of platform loss of control.

[0054] To address the aforementioned technical issues, the safety protection of hydraulic lifting platforms needs to shift from single-signal triggering to multi-source joint judgment of operating status. This involves pressure, tilt angle, and descent speed all contributing to platform operating status identification, and the judgment results are directly linked to the control of the solenoid directional valve. After the platform enters the first-level safety protection state, it continues to collect hydraulic pressure changes to distinguish whether an anomaly has occurred in the first-level protection. This, combined with subsequent tilt angle and descent speed data, identifies the second-level safety protection state. By integrating a system architecture of hydraulic drive, sensor detection, and electronic control execution, the hydraulic lifting platform gains layered judgment and continuous response capabilities under complex working conditions, thereby improving the reliability of safety protection response and fault adaptability.

[0055] To make the above-mentioned objectives, features, and advantages of the embodiments of this application more apparent and understandable, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0056] 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.

[0057] Figure 1 Flowchart of the safety protection method for the hydraulic lifting platform provided in this application Figure 1 In this embodiment, the executing entity is, for example, a controller. Figure 1 As shown, the method includes:

[0058] S101: Obtain the operating status parameters of the hydraulic lifting platform, including the first hydraulic pressure, the first platform tilt angle, and the first platform descent speed.

[0059] The first hydraulic pressure is used to characterize the current hydraulic operating state of the hydraulic lifting platform.

[0060] The first platform tilt angle is used to characterize the current attitude change of the platform.

[0061] The descent velocity of the first platform is used to characterize the motion state of the platform during its descent.

[0062] Specifically, after the controller acquires the first hydraulic pressure, the first platform tilt angle, and the first platform descent speed, it can be used as characterizing data of the current operating status of the hydraulic lifting platform, providing a basis for subsequent electromagnetic directional valve control.

[0063] S102: Based on the first hydraulic pressure, the first platform tilt angle, and the first platform descent speed, control the opening and closing of the electromagnetic directional valve in the hydraulic lifting platform to determine whether the hydraulic lifting platform enters the first-level safety protection state.

[0064] Among them, Level 1 security protection status refers to the first layer of protection that the platform enters after detecting abnormal signs.

[0065] Specifically, the controller judges the operating status of the hydraulic lifting platform based on the obtained first hydraulic pressure, first platform tilt angle and first platform descent speed, and outputs control signals to the solenoid directional valve accordingly to determine whether the hydraulic lifting platform has entered the first-level safety protection state.

[0066] Upon detecting abnormal signs on the hydraulic lifting platform, the system enters its first-level protective operating state, and the judgment result can be recorded by the controller. The operating status parameters are then correlated with the control actions of the solenoid directional valve, thus intervening in the oil circuit status and forming a primary safety protection link.

[0067] S103: When the hydraulic lifting platform enters the first-level safety protection state, obtain the second hydraulic pressure, and determine whether the first-level safety protection state is abnormal based on the first hydraulic pressure and the second hydraulic pressure.

[0068] The second hydraulic pressure is used to characterize the pressure state after the hydraulic lifting platform enters the first-level safety protection state.

[0069] Specifically, after the controller confirms that the hydraulic lifting platform has entered the first-level safety protection state, it continues to monitor the hydraulic lifting platform. After acquiring the second hydraulic pressure, the controller compares the first hydraulic pressure with the second hydraulic pressure to determine whether the first-level safety protection state is abnormal. An abnormality in the first-level safety protection refers to any further abnormalities discovered under the first-level safety protection state. The controller can generate a first-level safety protection verification result based on the comparison result of the first and second hydraulic pressures, and use it for subsequent second-level protection judgments.

[0070] After the first-level safety protection is established, a second hydraulic pressure is introduced to make a correlation judgment between the preceding and following steps, so that the controller can distinguish between the different states of the first-level safety protection being established and the abnormality still existing after the first-level safety protection is established, thereby providing triggering conditions for subsequent higher-level protection.

[0071] S104: If the first-level safety protection status is determined to be abnormal, obtain the tilt angle of the second platform and the descent speed of the second platform, and determine the second-level safety protection status of the hydraulic lifting platform based on the tilt angle of the second platform and the descent speed of the second platform.

[0072] The second platform tilt angle is used to characterize the subsequent attitude state of the platform after a level 1 safety protection anomaly.

[0073] The descent speed of the second platform is used to characterize the subsequent motion state of the platform after a failure of the first-level safety protection.

[0074] Level 2 security protection status is used to further identify whether platform anomalies are escalating, building upon Level 1 security protection.

[0075] Specifically, upon determining an anomaly in the Level 1 safety protection, the controller initiates the Level 2 safety protection judgment process. After acquiring the tilt angle and descent speed of the second platform, the controller determines the Level 2 safety protection status of the hydraulic lifting platform based on these parameters. The controller can then output corresponding execution results based on the Level 2 safety protection status.

[0076] After verifying the anomaly at the first-level pressure, a second platform tilt angle and a second platform descent speed are introduced for secondary identification, expanding the platform anomaly judgment from the hydraulic dimension to the attitude and speed dimensions, thus forming a layered and continuous safety protection process.

[0077] Based on the above analysis, this application provides a safety protection method for a hydraulic lifting platform, comprising: acquiring operating status parameters of the hydraulic lifting platform, including a first hydraulic pressure, a first platform tilt angle, and a first platform descent speed; controlling the opening and closing of an electromagnetic directional valve in the hydraulic lifting platform according to the first hydraulic pressure, the first platform tilt angle, and the first platform descent speed to determine whether the hydraulic lifting platform has entered a first-level safety protection state; acquiring a second hydraulic pressure when the hydraulic lifting platform has entered a first-level safety protection state, and determining whether the first-level safety protection state is abnormal based on the first hydraulic pressure and the second hydraulic pressure; and determining whether the first-level safety protection state is abnormal after determining the first-level safety protection state. In the event of an abnormal state, the tilt angle and descent speed of the second platform are obtained. Based on the tilt angle and descent speed of the second platform, the secondary safety protection state of the hydraulic lifting platform is determined. This method applies the judgment results of the first hydraulic pressure, the tilt angle of the first platform, and the descent speed of the first platform to the control of the solenoid directional valve. After the first-level safety protection is established, the second hydraulic pressure is used to perform a verification. Then, under the abnormal conditions of the first-level safety protection, the tilt angle and descent speed of the second platform are used to perform secondary identification. This constitutes a continuous processing link from anomaly detection, valve control intervention, first-level verification to second-level determination, enabling the hydraulic lifting platform to respond to abnormal working conditions in a layered manner.

[0078] Figure 2 Flowchart of the safety protection method for the hydraulic lifting platform provided in this application Figure 2 ,like Figure 2 As shown, in this embodiment... Figure 1Based on the embodiments, the safety protection method of the hydraulic lifting platform is described in detail, which includes:

[0079] S201: Obtain the operating status parameters of the hydraulic lifting platform, including the first hydraulic pressure, the first platform tilt angle, and the first platform descent speed.

[0080] Step S101 is similar to step S201, and will not be described again here.

[0081] S202: If at least one of the parameters of the first hydraulic pressure, the first platform tilt angle, and the first platform descent speed reaches the corresponding preset threshold, the solenoid directional valve is disconnected, and the hydraulic lifting platform is confirmed to enter the first-level safety protection state.

[0082] S203: If the first hydraulic pressure, the first platform tilt angle, and the first platform descent speed do not reach the corresponding preset threshold, the solenoid directional valve is closed to confirm that the hydraulic lifting platform has not entered the first-level safety protection state.

[0083] Specifically, pressure sensors, tilt sensors, and displacement velocity sensors detect and output corresponding acquisition signals. The controller filters and quantizes these signals, then compares them one by one with their respective preset thresholds. When any parameter reaches its corresponding preset threshold, the controller outputs a disconnect control signal, de-energizing the solenoid directional valve coil and switching it to the disconnected state. The hydraulic oil circuit is cut off, and the hydraulic lifting platform maintains its current posture and stops operating in its original motion state, thus forming a first-level safety protection state. When all three parameters are below the preset thresholds, the controller keeps the solenoid directional valve closed, keeping the oil circuit open and maintaining normal lifting control.

[0084] By directly controlling the opening and closing of the solenoid directional valve based on the combined judgment results of pressure, tilt angle, and descent speed, a one-to-one correspondence is established between the valve body state and the first-level safety protection state, and abnormal signals are quickly converted into oil circuit cut-off actions. Since the triggering conditions of the first-level safety protection are jointly limited by one or more operating parameters, the platform can promptly enter the first-level safety protection state when abnormal load, attitude deviation, or descent stall occurs, while maintaining valve circuit continuity under normal operating conditions, without affecting continuous operation.

[0085] With this method, the control timing of the electromagnetic directional valve is synchronized with the abnormal operation detection results. The hydraulic lifting platform can quickly establish a first-level safety protection state when the parameters reach the preset threshold, and maintain normal operation when the parameters do not reach the preset threshold. This enables a direct linkage between safety control and hydraulic actuator, improving the reliability of the first-level safety protection judgment and the consistency of control response.

[0086] For example, the first hydraulic pressure corresponds to a preset threshold. The first platform tilt angle corresponds to a preset threshold. The descent speed of the first platform corresponds to a preset threshold. .

[0087] S204: When the hydraulic lifting platform enters the first-level safety protection state, after the hydraulic lifting platform has entered the first-level safety protection state for a preset time, the second hydraulic pressure is obtained.

[0088] S205: Calculate the pressure change between the first hydraulic pressure and the second hydraulic pressure.

[0089] S206: If the pressure change is greater than the preset pressure change threshold, the first-level safety protection status is determined to be abnormal.

[0090] S207: If the pressure change is less than or equal to the preset pressure change threshold, then the first-level safety protection status is determined to be normal.

[0091] The pressure change can be obtained by the controller by calculating the difference between the first hydraulic pressure and the second hydraulic pressure, and the difference can be in absolute form to characterize the degree of pressure deviation between the two samplings.

[0092] The preset pressure change threshold is stored in the controller parameter area, and its value can be calibrated based on the hydraulic cylinder sealing status, pipeline elastic deformation range, and equipment rated load.

[0093] Specifically, when the pressure change exceeds the threshold, the controller outputs a Level 1 safety protection status abnormality signal and transmits the result to subsequent protection logic; when the pressure change is less than or equal to the preset pressure change threshold, the controller maintains the judgment result of Level 1 safety protection status being normal.

[0094] By acquiring the second hydraulic pressure after the first-level safety protection state has reached a preset duration and comparing the two pressure differences with a threshold, the first-level safety protection anomaly judgment can be based on stable pressure information. This distinguishes pressure fluctuations from continuous abnormal states, making the basis for subsequent protection and control clearer and ensuring the consistency and reliability of the first-level safety protection state judgment.

[0095] S208: If the first-level safety protection status is determined to be abnormal, obtain the tilt angle of the second platform and the descent speed of the second platform. If the tilt angle of the second platform is less than the preset tilt angle and the descent speed of the second platform is less than the preset speed, then the second-level protection status is determined to be normal.

[0096] S209: If the tilt angle of the second platform is greater than or equal to the preset tilt angle, or the descent speed of the second platform is greater than or equal to the preset speed, then the secondary protection status is determined to be abnormal.

[0097] The preset tilt angle can be set to a fixed threshold based on the rated load, support span, and allowable attitude deviation of the hydraulic lifting platform. For example, the preset tilt angle is... .

[0098] The preset speed can be set to a fixed threshold based on the allowable drop value of the hydraulic cylinder. For example, the preset speed is... .

[0099] Specifically, after acquiring the tilt angle and descent speed of the second platform, the controller compares them with preset tilt angle and preset speed, respectively. When the tilt angle of the second platform is less than the preset tilt angle and the descent speed of the second platform is less than the preset speed, the controller outputs a normal secondary protection status signal and writes the result to the safety status register; when either parameter is greater than or equal to the corresponding threshold, the controller outputs an abnormal secondary protection status signal and triggers subsequent alarm or shutdown control.

[0100] The combined judgment of the hydraulic lifting platform's attitude and descent speed distinguishes whether the current operation is still within a controllable range. Since the platform tilt angle reflects the platform's imbalance trend and the descent speed reflects the degree of instability, incorporating both into the judgment ensures that the output of the secondary safety protection status corresponds to the platform's actual operating state, thus forming a hierarchical judgment chain. This allows for continued joint identification of the platform's tilt and descent states even after a primary safety protection anomaly. A normal result is output when both parameters are below the threshold, and an abnormal result is output when either parameter is greater than or equal to the corresponding threshold. This gives the secondary safety protection judgment clear threshold boundaries and control direction, thereby improving the continuity and consistency of safety protection status identification.

[0101] S210: If the hydraulic lifting platform moves to a preset limit position when the level 2 safety protection is determined to be abnormal, the hydraulic lifting platform is determined to enter the level 3 safety protection state.

[0102] Among them, the preset limit position refers to the boundary position that is pre-set for the running direction of the hydraulic lifting platform. This position can be calibrated according to the platform's rated stroke, installation environment, and the position of the mechanical limit structure.

[0103] Level 3 security protection status indicates that the platform has entered a higher level of ultimate protection zone.

[0104] Specifically, when the hydraulic lifting platform reaches the preset limit position, the controller receives the corresponding limit signal, determines that the platform has reached the predetermined boundary based on the running direction, and identifies this state as a level three safety protection trigger condition. In this state, the hydraulic lifting platform can further activate mechanical limit, power failure holding, or forced shutdown control logic to keep the hydraulic lifting platform within the safety boundary.

[0105] During operation, when the hydraulic lifting platform continuously rises and falls and reaches the preset limit position, the controller samples and judges the limit input signal. If the valid level or position signal corresponding to the limit position is met, the controller outputs a control command for the platform to enter the third-level safety protection state, and records this state separately from the aforementioned first-level and second-level safety protection states. If the platform continues to move towards the limit boundary after the first-level or second-level safety protection stage, this judgment can be used as a fallback trigger condition to ensure that the platform eventually enters the third-level safety protection state if the abnormality persists.

[0106] By determining that the platform enters a level-three safety protection state when it reaches a preset limit position, the platform can trigger the final protection logic upon reaching the boundary position, forming a continuous connection with the aforementioned hierarchical protection chain. This method enables the controller to provide a timely final protection decision under extreme operating conditions, reliably locking the platform's operating state at the boundary position, thereby improving the overall safety and protection integrity of the hydraulic lifting platform.

[0107] Figure 3 This is a schematic diagram of the structure of the hydraulic lifting platform provided in an embodiment of this application. Figure 3 As shown, this application embodiment provides a hydraulic lifting platform, which includes a platform body 1, a hydraulic cylinder 2, an electromagnetic reversing valve 3, a hydraulic lock 4, a speed limiting valve 5, and a controller;

[0108] Hydraulic cylinder 2 is connected to platform body 1 and is used to drive platform body 1 to perform lifting and lowering movements;

[0109] The electromagnetic directional valve 3 is connected to the hydraulic cylinder 2 and is used to control the on / off of the hydraulic oil circuit corresponding to the hydraulic cylinder 2.

[0110] The hydraulic lock 4 is installed in the hydraulic oil circuit corresponding to the hydraulic cylinder 2. It is used to maintain the state of the hydraulic oil in the hydraulic cylinder 2 when the solenoid directional valve 3 disconnects the hydraulic oil circuit, and to restrict the extension and retraction of the hydraulic cylinder 2.

[0111] The speed limiting valve 5 is installed in the return oil line of the hydraulic cylinder 2 to limit the descent speed of the hydraulic cylinder 2;

[0112] The controller is connected to the solenoid directional valve 3 to perform any of the above-mentioned safety protection methods for the hydraulic lifting platform.

[0113] The platform body 1 refers to the main structure that carries the work object and moves up and down with the hydraulic lifting platform. As the object that carries and outputs motion, it forms a motion coupling relationship with the hydraulic cylinder 2. It is usually located on the upper part of the lifting mechanism and is connected to the hydraulic cylinder 2 through a connecting rod, hinge seat, or guide mechanism to convert the linear thrust of the hydraulic cylinder 2 into the lifting displacement of the platform. For example, the platform body 1 can take the form of a rectangular plate frame, a box-shaped load-bearing platform, or a welded steel frame platform, and the material can be steel or aluminum alloy profiles.

[0114] Hydraulic cylinder 2 refers to the actuator that converts hydraulic oil pressure into linear reciprocating motion. In the overall device, it serves as a drive component connected to the platform body 1. When the solenoid directional valve 3 opens the hydraulic oil circuit, it pushes the platform body 1 to rise or retract, thereby causing the platform to descend. Hydraulic cylinder 2 is typically located below or on either side of the platform body 1 and is connected to the platform body 1 via a piston rod, trunnion seat, or hinge to transmit the linear motion of hydraulic cylinder 2 to the platform mechanism. For example, hydraulic cylinder 2 can be implemented as a single-acting hydraulic cylinder, a double-acting hydraulic cylinder, or a differential hydraulic cylinder.

[0115] The electromagnetic directional valve 3 is an electrically controlled valve used to switch the on / off state of the hydraulic oil circuit. It is electrically connected to the controller in the overall device and is located in the main oil circuit between the hydraulic pump station and the hydraulic cylinder 2. It is used to change the oil inlet, oil return, or pressure holding state of the hydraulic cylinder 2 according to the controller's instructions, thereby realizing the extension, retraction, or stopping of the platform body 1. For example, the electromagnetic directional valve 3 can adopt three structures: a two-position three-way valve, a three-position four-way valve, or a two-position four-way valve. The electromagnetic coil can be a DC coil, an AC coil, or an explosion-proof coil.

[0116] Hydraulic lock 4 refers to a pressure-holding and locking element installed in the hydraulic circuit corresponding to hydraulic cylinder 2. It is connected in series or parallel near the oil inlet of hydraulic cylinder 2 or in the main oil circuit in the overall device. It is used to seal the hydraulic oil and maintain the current state of hydraulic cylinder 2 when the solenoid directional valve 3 disconnects the hydraulic oil circuit, thereby restricting the extension and retraction of hydraulic cylinder 2. For example, hydraulic lock 4 can take the form of a hydraulically controlled check valve, a hydraulic check lock, or a two-way locking valve.

[0117] The speed limiting valve 5 is a flow control element installed in the return oil line of the hydraulic cylinder 2. It is located in the overall device in the return oil branch, the main return oil line, or near the return oil port of the hydraulic cylinder 2. It is used to throttle and limit the return oil flow during the descent of the hydraulic cylinder 2, ensuring that the platform's descent is under control. For example, the speed limiting valve 5 can be implemented using three methods: a throttle valve, a one-way speed limiting valve, or a pressure-compensated speed limiting valve.

[0118] The controller is a control unit used to implement safety protection methods and coordinate the actions of various electro-hydraulic components. It is electrically connected to the solenoid directional valve 3 in the overall device and can be installed in the control cabinet, the side wall of the equipment base, or an independent electrical control box. It is used to receive and process safety protection-related signals, and then output control commands to drive the solenoid directional valve 3 to act and achieve safety protection.

[0119] The hydraulic lifting platform provided in this application, when started, has a controller that controls the solenoid directional valve 3 to allow hydraulic oil to flow in the main oil circuit in a set direction and enter the hydraulic cylinder 2. The hydraulic cylinder 2, under the action of pressurized oil, pushes the platform body 1 to complete the lifting or retraction action. Once the hydraulic lifting platform enters the working position, the controller continuously manages the solenoid directional valve 3 and its associated hydraulic state. When it is necessary to maintain the position, the solenoid directional valve 3 switches to an open or pressure-holding state, and the hydraulic lock 4 immediately locks the corresponding hydraulic oil circuit, keeping the hydraulic oil in the hydraulic cylinder 2 in a predetermined state. The platform body 1 thus maintains its current position and does not undergo uninstructed displacement. If the hydraulic lifting platform enters the descent process, the hydraulic oil on the return side is throttled by the speed limiting valve 5 and returns to the oil tank. The return flow is constrained, and the piston rod of the hydraulic cylinder 2 can only retract at a controlled speed, thus keeping the descent process of the hydraulic lifting platform stable. By combining the controller's linkage control of the solenoid directional valve 3 with the direct constraints of the hydraulic circuit state by the hydraulic lock 4 and the speed limiter valve 5, the hydraulic lifting platform can switch to a locked or controlled descent state when abnormal working conditions occur. This transforms simple signal judgment into direct hydraulic execution control, thereby forming a safety protection system that maintains the platform's position, suppresses abnormal sliding, and constrains the descent process. Thus, under complex working conditions, the hydraulic lifting platform can achieve integrated linkage of lifting action and safety control through the coordinated operation of the hydraulic cylinder 2, solenoid directional valve 3, hydraulic lock 4, and speed limiter valve 5, improving its adaptability to heavy-duty operations, pressure fluctuations, and changes in the state of the actuator.

[0120] In one possible implementation, the hydraulic lifting platform also includes: a pressure sensor 6, a tilt sensor 7, and a speed sensor 8;

[0121] Pressure sensor 6 is installed in the hydraulic oil circuit corresponding to hydraulic cylinder 2 to detect the hydraulic pressure of hydraulic cylinder 2;

[0122] The tilt sensor 7 is installed on the platform body 1 to detect the tilt angle of the platform body 1;

[0123] Speed ​​sensor 8 is used to detect the descent speed of platform body 1;

[0124] Pressure sensor 6, tilt sensor 7, and speed sensor 8 are connected to the controller.

[0125] The pressure sensor 6 is a measuring element used to convert pressure changes in the hydraulic circuit corresponding to the hydraulic cylinder 2 into an electrical signal output. Its function is to reflect the load status of the hydraulic system, the fluctuation of the hydraulic circuit, and the force changes of the hydraulic cylinder 2 in real time. For example, the pressure sensor 6 can be arranged at a pressure monitoring point near the oil inlet line, main oil supply line, or hydraulic lock 4 of the hydraulic cylinder 2. The sensor output can be an analog voltage signal, a standard current signal, or a digital communication signal.

[0126] The tilt sensor 7 is an angle measuring element used to detect the tilt angle of the platform body 1 relative to the horizontal reference plane. Its function is to sense the platform's attitude deviation in real time and feed back the degree of tilt to the controller so that safety protection can be triggered in time when the platform tilts, is unbalanced, or is subjected to uneven force. For example, the tilt sensor 7 can be in the form of an electronic level or a dual-axis / triaxial angle sensor.

[0127] Speed ​​sensor 8 is a speed measurement element used to obtain the descent speed of platform body 1. Its function is to monitor the motion state of the platform during descent and identify abnormal situations such as overspeed descent, uncontrolled slippage, or sudden speed changes. For example, speed sensor 8 can be set at platform body 1, guide mechanism, hydraulic cylinder 2 return oil line, or detection position associated with platform motion.

[0128] Pressure sensor 6, tilt sensor 7, and speed sensor 8 are connected to the controller so that the controller can synchronously collect, jointly analyze, and coordinate the hydraulic pressure, platform attitude, and descent speed, thereby forming a basis for multi-source status judgment.

[0129] For example, when the hydraulic lifting platform is started, the controller first initializes and zero-point calibrates the pressure sensor 6, tilt sensor 7, and speed sensor 8. During the process of the platform rising, holding pressure, or falling, the pressure sensor 6 continuously collects the pressure changes of the hydraulic oil circuit corresponding to the hydraulic cylinder 2 and outputs real-time pressure data (e.g., first hydraulic pressure, second hydraulic pressure) to the controller. The tilt sensor 7 synchronously detects the attitude deviation of the platform body 1 relative to the horizontal plane (e.g., first platform tilt angle, second platform tilt angle). The speed sensor 8 continuously feeds back the descent speed information of the platform body 1 (e.g., first platform descent speed, second platform descent speed). The controller makes a joint judgment on the platform's operating status based on the above three signals. When the hydraulic pressure fluctuates abnormally, the platform tilt angle exceeds the preset threshold, or the descent speed is higher than the set range, the controller can promptly identify the abnormal trend and output corresponding control commands to control the solenoid directional valve 3 in conjunction with the hydraulic lock 4 to maintain the state of the hydraulic cylinder 2 and suppress further descent with the help of the speed limiting valve 5. Since the three parameters of pressure, attitude, and speed are not judged separately, but complement each other to reflect the hydraulic load state, platform balance state, and motion stability state, the controller can more accurately distinguish between normal fluctuations and fault symptoms under heavy load impact, pipeline fluctuation, local failure, or off-center load conditions. This reduces protection omissions caused by misjudgment of a single signal and improves the platform's response reliability and fault adaptability in complex working conditions.

[0130] In one possible implementation, two hydraulic cylinders 2, two solenoid directional valves 3, two hydraulic locks 4, and two speed limiting valves 5 are provided.

[0131] Two hydraulic cylinders 2 are respectively located on both sides of the platform body 1, each with an independent hydraulic circuit;

[0132] Each hydraulic cylinder 2 is equipped with a solenoid directional valve 3, a hydraulic lock 4, and a speed limit valve 5.

[0133] The two hydraulic cylinders 2 form a dual-drive unit arranged symmetrically on the left and right sides, which are used to provide lifting driving force to both sides of the platform body 1 and to share the load, thereby improving the platform's posture stability and load uniformity under off-center loading conditions. The two hydraulic cylinders 2 are respectively installed on the two side supports under the platform body 1, on both sides of the guide frame, or on the corresponding mounting positions that are hinged to the platform, and are connected to the control elements through their own independent hydraulic oil circuits to avoid a single path failure affecting the operation of the entire platform.

[0134] Each hydraulic cylinder 2 is equipped with a corresponding solenoid directional valve 3, a hydraulic lock 4, and a speed limiter valve 5. This means that each hydraulic circuit has independent on / off control, lock-up protection, and descent speed limiting capabilities. Typically, the solenoid directional valve 3 is located on the main hydraulic line between the hydraulic pump and the hydraulic cylinder 2, the hydraulic lock 4 is located in the corresponding inlet and return oil branch of the hydraulic cylinder 2, and the speed limiter valve 5 is located on the return oil line of the hydraulic cylinder 2. The three components can be connected by flanges, threads, or integrated valve blocks to form an integrated circuit.

[0135] The two hydraulic cylinders 2 and their corresponding solenoid directional valves 3, hydraulic locks 4 and speed limiting valves 5 can be implemented by using parallel independent circuits, left and right flow split circuits or dual pump dual valve circuits. The two circuits are structurally independent but functionally coordinated. When one circuit experiences pressure drop, valve jamming or hydraulic oil leakage, the other side can still maintain basic support or complete descent under controlled conditions, thereby reducing the impact of single-point failure on the safety of the entire platform.

[0136] For example, when the hydraulic lifting platform is started, the controller outputs control signals to the solenoid directional valves 3 on both sides, causing the two hydraulic oils to enter the corresponding hydraulic cylinders 2 in a predetermined direction. The two hydraulic cylinders 2 extend synchronously or with a preset slight difference, jointly lifting the platform body 1 and sharing the load on the left and right sides. During the lifting process, the two hydraulic locks 4 can promptly close their respective circuits when the valve ports are closed or the control signal is abnormal, preventing the hydraulic cylinders 2 from retracting on their own due to pressure fluctuations. The two speed limiting valves 5 limit the return oil flow during the descent phase, allowing the platform to descend at a stable speed without impact. Since each side has an independent hydraulic circuit, when a partial failure occurs in one hydraulic cylinder 2 or its corresponding valve, the circuit on the other side can still maintain support or execute a controlled shutdown under the intervention of the controller. This gives the platform better redundancy and attitude maintenance capabilities under heavy load, off-center load, or complex working conditions, reducing the risk of platform tilting, instability, and sudden falls caused by single-circuit failure, and providing higher action certainty and execution reliability for subsequent safety protection control.

[0137] In one possible implementation, the hydraulic lifting platform further includes: a limit stop 9;

[0138] The limit block 9 is set at the extreme position of the movement of the platform body 1. It is used to mechanically block the platform body 1 when both the first-level safety protection state and the second-level safety protection state fail, so as to limit the platform body 1 from continuing to move.

[0139] Specifically, the limit stop 9 is a mechanical limiting component used to provide hard contact blocking for the platform body 1 under extreme failure conditions. Essentially, it is a passive safety element that functions independently without relying on electronic control signals or hydraulic holding capabilities. The purpose of this component is that when the controller fails to promptly suppress abnormal movement of the platform body 1 under both the primary and secondary safety protection states established by the pressure sensor 6, tilt sensor 7, and speed sensor 8, it can still directly absorb or withstand the end-of-stroke impact force of the platform body 1 through a rigid structure. This forcibly terminates the continued descent, ascent, or overtravel of the platform body 1, preventing it from exceeding its predetermined stroke and causing a fall, collision, or structural instability. The limit stop 9 is typically positioned at the extreme movement limit of the platform body 1, or in the area on the support base corresponding to the end of the platform's movement trajectory. It can also be positioned within the projected area of ​​the platform guide structure, column structure, or stroke end, allowing it to make direct contact with the bottom, side beams, guide wheel seats, or load-bearing frame of the platform body 1 when it reaches its extreme position. The installation method can be welding, bolting, or embedding to ensure that the stop block maintains stable installation rigidity and positional accuracy when subjected to repeated impacts. A single-sided or bi-directional limiting structure can be set according to the running direction of the platform body 1. For example, the limiting stop block 9 can be any of three forms: block-shaped stop, wedge-shaped stop, or boss-type stop. Block-shaped stop blocks provide a larger contact area to disperse impact stress, wedge-shaped stop blocks facilitate guidance and buffering transition at the moment of contact, and boss-type stop blocks are suitable for installation scenarios with limited structural space.

[0140] For example, when the hydraulic lifting platform is started, the platform body 1 completes the lifting movement according to the controller's instructions under the drive of the hydraulic cylinder 2. Under normal working conditions, the limit stop 9 does not participate in active action, but is stationary at the predetermined limit position, existing as the end mechanical safety boundary. When the controller determines that the first-level safety protection state and the second-level safety protection state have failed based on the combined signals of the pressure sensor 6, the tilt sensor 7 and the speed sensor 8, and the electromagnetic reversing valve 3, the hydraulic lock 4 or the speed limiting valve 5 fails to terminate the abnormal movement of the platform body 1 in time, the platform body 1 will continue to move towards the movement limit position and eventually come into contact with the limit stop 9. The stop relies on its own rigidity and the mounting support surface to bear the impact load of the platform body 1, limiting the continued displacement of the platform body 1 within the predetermined range, thereby providing the last passive mechanical barrier after the failure of the electrical control protection and hydraulic protection. Therefore, the limit stop 9 in this application can form a hierarchical safety cooperation with the aforementioned hydraulic control and sensor protection links. When the previous protection fails, the platform body 1 can still be prevented from running over the limit by physical stop, thereby improving the safety redundancy and fault tolerance of the hydraulic lifting platform under extreme abnormal working conditions.

[0141] In one possible implementation, the hydraulic lifting platform further includes: an upper limit switch 10 and a lower limit switch 11;

[0142] The upper limit switch 10 and the lower limit switch 11 are respectively set at the corresponding motion limit positions of the platform body 1;

[0143] The controller is connected to the upper limit switch 10 and the lower limit switch 11 respectively, and is used to detect when the hydraulic lifting platform runs to the preset limit position according to the upper limit switch 10 and the lower limit switch 11, and trigger the three-level safety protection.

[0144] Among them, the upper limit switch 10 is used to detect when the platform body 1 reaches the upper movement limit position and output the upper limit position signal.

[0145] The lower limit switch 11 is used to detect when the platform body 1 reaches the lower movement limit position and output the lower limit position signal.

[0146] Specifically, the upper limit switch 10 and the lower limit switch 11 are respectively set at the corresponding motion limit positions of the platform body 1. During installation, they can be arranged at the end of the guide rail, the top of the support frame, the end of the base, or on a fixed bracket corresponding to the platform's lifting path, forming a relative cooperative relationship with the triggering components on the platform body 1, enabling the platform to trigger a travel action when it is raised to the preset position. The controller is connected to the upper limit switch 10 and the lower limit switch 11 respectively. The connection between the controller and the limit switches can be a wired connection, an anti-interference shielded connection, or a dual-circuit redundant connection, so that the controller can receive the limit position signal in real time and output a three-level safety protection control command after determining that the hydraulic lifting platform has reached the preset limit position. In this application, the three-level safety protection corresponds to the final overtravel protection, which can be linked to the electromagnetic directional valve 3 to perform control actions such as power-off, reversing back to center, holding, or braking, thereby limiting the platform body 1 from continuing to move in the limit direction.

[0147] For example, when the hydraulic lifting platform is started, the controller drives the hydraulic cylinder 2 to lift the platform body 1 after receiving the lifting command. During the upward movement of the platform, the upper limit switch 10 and the triggering component on the platform body 1 gradually approach each other. When the platform moves to the preset upper limit position, the triggering component causes the upper limit switch 10 to change state and outputs a position signal to the controller. The controller determines that the platform has reached the upper limit position and immediately triggers the three-level safety protection. Similarly, when the platform moves downward and approaches the lower limit position, the lower limit switch 11 will be triggered when the platform approaches the preset lower limit position. The controller determines that the platform has reached the lower limit position based on the lower limit signal and executes the corresponding three-level safety protection control. Since the upper limit switch 10 and the lower limit switch 11 independently detect the upper and lower boundary positions of the platform, the controller can form a direct boundary lock when the platform approaches or reaches the limit position, preventing the platform from continuing to run beyond its travel range under the action of inertia, pressure fluctuations or control delay. This provides the final stage of mechanical travel protection for the hydraulic system and complements the previous stage's state judgment based on pressure, tilt angle and speed. This allows the platform to maintain reliable shutdown and limit control effects under complex working conditions, thereby improving the operational safety and fault adaptability of the hydraulic lifting platform.

[0148] The various embodiments or implementation methods described in this specification are presented in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other.

[0149] It should be noted that the embodiments referred to in the specification, such as "one embodiment," "embodiment," "exemplary embodiment," and "some embodiments," may include specific features, structures, or characteristics, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.

[0150] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A safety protection method for a hydraulic lifting platform, characterized in that, Applied to hydraulic lifting platforms, the method includes: The operating status parameters of the hydraulic lifting platform are obtained, including the first hydraulic pressure, the first platform tilt angle, and the first platform descent speed. Based on the first hydraulic pressure, the first platform tilt angle, and the first platform descent speed, the opening and closing of the electromagnetic reversing valve in the hydraulic lifting platform is controlled to determine whether the hydraulic lifting platform enters the first-level safety protection state. When the hydraulic lifting platform enters the first-level safety protection state, the second hydraulic pressure is obtained, and based on the first hydraulic pressure and the second hydraulic pressure, it is determined whether the first-level safety protection state is abnormal. If the first-level safety protection status is determined to be abnormal, the tilt angle of the second platform and the descent speed of the second platform are obtained. Based on the tilt angle of the second platform and the descent speed of the second platform, the second-level safety protection status of the hydraulic lifting platform is determined.

2. The method according to claim 1, characterized in that, The step of controlling the opening and closing of the solenoid directional valve in the hydraulic lifting platform based on the first hydraulic pressure, the first platform tilt angle, and the first platform descent speed to determine whether the hydraulic lifting platform enters the first-level safety protection state includes: If at least one of the parameters of the first hydraulic pressure, the first platform tilt angle, and the first platform descent speed reaches the corresponding preset threshold, the electromagnetic reversing valve is controlled to disconnect, and the hydraulic lifting platform is determined to enter the first-level safety protection state. If none of the first hydraulic pressure, the first platform tilt angle, or the first platform descent speed reaches the corresponding preset threshold, the electromagnetic reversing valve is closed to determine that the hydraulic lifting platform has not entered the first-level safety protection state.

3. The method according to claim 1, characterized in that, The step of obtaining the second hydraulic pressure and determining whether the first-level safety protection status is abnormal based on the first hydraulic pressure and the second hydraulic pressure includes: After the hydraulic lifting platform has entered the first-level safety protection state for a preset time, the second hydraulic pressure is obtained; Calculate the pressure change between the first hydraulic pressure and the second hydraulic pressure; If the pressure change is greater than the preset pressure change threshold, then the first-level safety protection status is determined to be abnormal. If the pressure change is less than or equal to the preset pressure change threshold, then the first-level safety protection status is determined to be normal.

4. The method according to claim 1, characterized in that, The step of determining the secondary safety protection status of the hydraulic lifting platform based on the tilt angle and descent speed of the second platform includes: If the tilt angle of the second platform is less than the preset tilt angle and the descent speed of the second platform is less than the preset speed, then the secondary protection status is determined to be normal. If the tilt angle of the second platform is greater than or equal to the preset tilt angle, or the descent speed of the second platform is greater than or equal to the preset speed, then the secondary protection status is determined to be abnormal.

5. The method according to any one of claims 1-4, characterized in that, The method further includes: If the hydraulic lifting platform moves to a preset limit position when the level 2 safety protection status is determined to be abnormal, then the hydraulic lifting platform is determined to enter the level 3 safety protection status.

6. A hydraulic lifting platform, characterized in that, The hydraulic lifting platform includes a platform body, a hydraulic cylinder, a solenoid directional valve, a hydraulic lock, a speed limiting valve, and a controller. The hydraulic cylinder is connected to the platform body and is used to drive the platform body to perform lifting and lowering movements; The electromagnetic directional valve is connected to the hydraulic cylinder and is used to control the on / off state of the hydraulic oil circuit corresponding to the hydraulic cylinder. The hydraulic lock is installed in the hydraulic circuit corresponding to the hydraulic cylinder and is used to maintain the state of the hydraulic oil in the hydraulic cylinder when the solenoid directional valve disconnects the hydraulic circuit, thereby restricting the extension and retraction of the hydraulic cylinder. The speed limiting valve is installed in the return oil line of the hydraulic cylinder to limit the descent speed of the hydraulic cylinder; The controller is connected to the electromagnetic reversing valve and is used to execute the safety protection method of the hydraulic lifting platform according to any one of claims 1-5.

7. The hydraulic lifting platform according to claim 6, characterized in that, The hydraulic lifting platform also includes: a pressure sensor, a tilt sensor, and a speed sensor; The pressure sensor is installed in the hydraulic circuit corresponding to the hydraulic cylinder to detect the hydraulic pressure of the hydraulic cylinder; The tilt sensor is installed on the platform body and is used to detect the tilt angle of the platform body; The speed sensor is used to detect the descent speed of the platform body; The pressure sensor, the tilt sensor, and the speed sensor are each connected to the controller.

8. The hydraulic lifting platform according to claim 6, characterized in that, The hydraulic cylinder, solenoid directional valve, hydraulic lock, and speed limit valve are all provided in two versions. The two hydraulic cylinders are respectively located on both sides of the platform body, each with an independent hydraulic circuit; Each of the hydraulic cylinders is respectively provided with an electromagnetic directional valve, a hydraulic lock, and a speed limiting valve.

9. The hydraulic lifting platform according to claim 6, characterized in that, The hydraulic lifting platform also includes: a limit stop; The limiting block is set at the extreme position of the platform body's movement and is used to mechanically block the platform body when both the primary and secondary safety protection states fail, thereby restricting the platform body from continuing to move.

10. The hydraulic lifting platform according to claim 9, characterized in that, The hydraulic lifting platform also includes: an upper limit switch and a lower limit switch; The upper limit switch and the lower limit switch are respectively set at the motion limit positions corresponding to the platform body; The controller is connected to the upper limit switch and the lower limit switch respectively, and is used to detect that the hydraulic lifting platform has run to a preset limit position according to the upper limit switch and the lower limit switch, and trigger the three-level safety protection.

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