Overload warning electric jack

Abstract

The present application relates to the technical field of jack manufacturing, and particularly relates to an overload early warning electric jack, which comprises a rack, a lifting arm, a driving component and an alarm module; the driving component comprises a motor, a pump station and a hydraulic cylinder; the motor drives the pump station to generate a hydraulic driving force, and the hydraulic cylinder is pushed by the hydraulic driving force to complete a lifting action; when any of the motor, the pump station and the hydraulic cylinder appears an abnormal overload working condition, the alarm module is triggered and an overload alarm prompt is sent, and at the same time, the motor, the pump station and the hydraulic cylinder synchronously receive a stop working instruction. In this way, the motor, the pump station, the hydraulic cylinder and other core driving components can be comprehensively protected against overload, so that a single component overload is avoided to cause a device failure; and when the overload occurs, the alarm prompt and the core component shutdown operation are synchronously completed, which not only prevents the overload component from continuously running from the source and avoids the device damage from being aggravated, but also enables an operator to timely know the overload condition, so as to provide clear guidance for taking disposal measures and avoiding safety risks.

Description

Technical Field

[0001] This invention relates to the field of jack manufacturing technology, and in particular to an overload warning electric jack. Background Technology

[0002] Electric jacks, as a commonly used lifting device, are widely used in various scenarios such as automobile repair, cargo handling, and engineering construction. An electric jack typically consists of a frame, a lifting boom, and a drive unit. Both the lifting boom and the drive unit are mounted on the frame. The drive unit comprises a motor, a pump station, and hydraulic cylinders. The motor drives the pump station to generate hydraulic force, which in turn drives the hydraulic cylinders, thus moving the lifting boom to complete the lifting operation.

[0003] In practical use, overload conditions are one of the main causes of electric jack equipment failure, shortened service life, and even safety accidents. When the lifting load exceeds the equipment's rated load, or when mechanical jamming or hydraulic circuit abnormalities occur during operation, the motor, pump station, and hydraulic cylinder may all fall into an overload state. The motor is prone to excessive current and abnormal speed due to excessive load, which can lead to coil burnout and motor damage; the pump station may experience pipeline leaks and seal damage due to abnormally high hydraulic circuit pressure; and the hydraulic cylinder may experience piston rod deformation and cylinder body damage due to bearing working pressure exceeding the rated pressure. This not only affects the normal use of the equipment but may also cause the lifted load to fall due to equipment failure, resulting in property damage or even personal injury.

[0004] While some electric jacks in the current technology are equipped with simple overload protection structures, such as local overload warnings through single pressure monitoring, the protection and warning performance of such solutions is significantly insufficient and cannot meet the safety requirements of actual operations. Specifically, the monitoring range of existing protection structures is limited, mostly targeting only a single component (such as monitoring only motor current or only hydraulic cylinder pressure) for overload protection. They cannot simultaneously cover the overload conditions of the three core components: motor, pump station, and hydraulic cylinder. When an unmonitored component overloads, it cannot be identified and dealt with in a timely manner. More importantly, existing solutions suffer from a lack of synchronization between protection and warning. Either they can only passively stop the machine after an overload, lacking active alarm notification functions, making it impossible for operators to be aware of the overload situation in time, which can easily lead to secondary risks due to misoperation, or they can only issue an alarm notification without simultaneously cutting off the motor power supply, causing the overloaded component to continue operating, failing to fundamentally resolve the safety hazards and equipment damage caused by overloads. Summary of the Invention

[0005] The purpose of this invention is to provide an overload warning electric jack, which aims to solve the problems of existing designs having limited monitoring range, failing to fully cover overload conditions of motors, pump stations, and hydraulic cylinders, and having asynchronous protection and warning, failing to simultaneously realize overload power cut-off and alarm prompts.

[0006] This invention relates to an overload warning electric jack, comprising a frame, a lifting arm, and a drive component; both the lifting arm and the drive component are mounted on the frame, and the lifting arm is controlled by the hydraulic driving force of the drive component; The drive components include a motor, a pump station, and a hydraulic cylinder; the motor drives the pump station to perform work and generate hydraulic driving force; the hydraulic cylinder is driven by the hydraulic driving force to push the lifting arm to complete the lifting action; Furthermore, the overload warning electric jack also includes an alarm module; when any of the motor, pump station, or hydraulic cylinder experiences an abnormal overload condition, the alarm module is triggered and issues an overload alarm prompt. At the same time, the motor, pump station, and hydraulic cylinder receive a stop operation command.

[0007] As a further improvement to the technical solution disclosed in this invention, the alarm module includes a buzzer and an indicator light; when any of the motor, pump station, or hydraulic cylinder experiences an abnormal overload, the buzzer continuously sounds, and at the same time, the indicator light flashes at a high frequency.

[0008] As a further improvement to the technical solution disclosed in this invention, the overload warning electric jack also includes a detection module and a control module; The detection modules are associated with the motor, pump station, and hydraulic cylinder respectively, and are used to detect the operating parameters of the motor, pump station, and hydraulic cylinder in real time and generate detection signals. The control module is electrically connected to the detection module, motor, and alarm module respectively, and pre-stores the corresponding operating parameter thresholds for the motor, pump station, and hydraulic cylinder. After receiving the detection signal, the control module compares the detection parameters of the motor, pump station, and hydraulic cylinder with the corresponding operating parameter thresholds. When any detection parameter of the motor, pump station, or hydraulic cylinder exceeds the corresponding operating parameter threshold, it is determined that the motor is in an abnormal overload condition.

[0009] As a further improvement to the technical solution disclosed in this invention, the detection module is electrically connected to the motor and is used to detect the motor's operating speed and operating current in real time; the operating parameter of the pump station is the hydraulic circuit differential pressure; and the operating parameter of the hydraulic cylinder is the operating pressure.

[0010] As a further improvement to the technical solution disclosed in this invention, the detection module is an integrated sensing module; the detection module is embedded in the end cover of the motor, and its detection end is positioned relative to the rotor shaft of the motor.

[0011] As a further improvement to the technical solution disclosed in this invention, the control module pre-stores motor overload classification thresholds; the motor overload classification thresholds include a first-level warning threshold and a second-level shutdown threshold that correspond one-to-one with the motor's operating speed and operating current thresholds. When the motor speed detection data is between the corresponding first-level warning threshold and the second-level shutdown threshold, or when the operating current detection data is between the corresponding first-level warning threshold and the second-level shutdown threshold, the control module outputs a speed reduction control signal to regulate the motor to reduce its operating speed. When the motor speed detection data is lower than the speed threshold corresponding to the secondary shutdown threshold, or the operating current detection data is greater than the current threshold corresponding to the secondary shutdown threshold, the control module outputs a power-off control signal to cut off the power supply to the motor and triggers the alarm module.

[0012] As a further improvement to the technical solution disclosed in this invention, the control module incorporates a comprehensive dynamic overload judgment model for the motor, realizing dynamic quantitative judgment of motor overload. The formula is as follows: ; Where S is the comprehensive value of dynamic overload of the motor; This refers to the real-time operating current of the motor. This refers to the rated operating current of the motor. This refers to the real-time operating speed of the motor. The rated operating speed of the motor; For current overload weighting, 0.6 ≤ ≤0.8, For speed overload weighting coefficient, 0.2≤ ≤0.4, and + =1; The overload trend time amplification factor is 0.02s. -1 ≤γ≤0.05s -1 , The duration for which the detected data continuously exceeds the corresponding Level 1 warning threshold; The control module pre-stores an overload comprehensive value S1 that matches the first-level warning threshold and an overload comprehensive value S2 that matches the second-level shutdown threshold, and 0 < S1 < S2; when S1 < S < S2, the control module is triggered to output a speed reduction control signal; when S ≥ S2, the control module is triggered to output a power-off control signal and trigger the alarm module.

[0013] As a further improvement to the technical solution disclosed in this invention, the control module constructs an adaptive speed reduction control model for hydraulic load based on the comprehensive value S of motor dynamic overload, thereby achieving matched control of motor speed and hydraulic load. The formula is as follows: ; in, The adaptive target speed reduction for the motor; k is the basic speed reduction coefficient, 0.3≤k≤0.5; This refers to the real-time differential pressure in the hydraulic circuit of the pump station. The rated operating differential pressure of the pumping station; the control module limits the minimum motor speed reduction to no less than 0.4. .

[0014] As a further improvement to the technical solution disclosed in this invention, it is applicable to undercarriage lifts, cranes, presses, elevators, and hydraulic supports.

[0015] In practical applications, the overload warning electric jack disclosed in this invention can achieve at least the following beneficial technical effects, specifically: 1) The alarm module can respond synchronously to the overload conditions of the three core components: motor, pump station, and hydraulic cylinder. No matter which component of the motor, pump station, or hydraulic cylinder is overloaded, the protection mechanism can be triggered to ensure that the core drive components can be protected against overload in all types of lifting operation scenarios, and to avoid equipment failure caused by the failure to protect a single component from overload. 2) When any of the motor, pump station, or hydraulic cylinder experiences an abnormal overload, the overload warning electric jack can simultaneously trigger the alarm module and stop the operation of the motor, pump station, or hydraulic cylinder. In this way, on the one hand, by immediately stopping the core drive components, the overloaded components are prevented from continuing to operate at the source, avoiding further damage to the equipment and extending its service life; on the other hand, by issuing an overload warning through the alarm module, operators can be aware of the abnormal operation of the equipment as soon as possible, providing clear guidance for them to take timely measures and avoid safety risks such as falling heavy objects, greatly improving the safety and reliability of the equipment. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a three-dimensional schematic diagram of the electric jack with automatic overload protection disclosed in this invention.

[0018] Figure 2 This is also a three-dimensional schematic diagram of the overload warning electric jack disclosed in this invention (with the drive component exposed).

[0019] Figure 3 This is a three-dimensional schematic diagram of the drive component of the electric jack with automatic overload protection disclosed in this invention (the control module is shown in parallel).

[0020] Figure 4 This is the overload protection control logic block diagram of the electric jack disclosed in this invention (taking motor overload control as an example).

[0021] 1-Frame; 2-Lifting boom; 3-Drive components; 31-Motor; 32-Pump station; 33-Hydraulic cylinder; 4-Control module; 5-Battery pack; 6-Operating handle. Detailed Implementation

[0022] The technical solution of the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings. Figure 1 , Figure 2 The diagrams show two different states of the overload warning electric jack disclosed in this invention. It can be seen that it mainly consists of a frame 1, a lifting arm 2, a drive component 3, a battery pack 5, and a control handle 6. The lifting arm 2, as the main structure directly bearing the load and performing the lifting action, is mounted on the frame 1. The drive component 3 is also mounted on the frame 1, providing continuous hydraulic driving force for the lifting action of the lifting arm 2. The battery pack 5 serves as the power supply unit for the equipment, providing stable power support to all the electrical control components and drive component 3 of the electric jack. The control handle 6 is detachably connected to the frame 1, allowing the operator to flexibly adjust the position of the frame 1 on the ground by pushing or rotating the control handle 6. The control handle 6 also serves as a manual operating end to input commands for starting, stopping, and lifting.

[0023] Drive component 3 is the core unit for realizing the hydraulic drive of the electric jack, such as Figure 3 As shown, it mainly consists of a motor 31, a pump station 32, and a hydraulic cylinder 33. The motor 31 serves as the active power source for the entire hydraulic drive system. Its output torque directly drives the pump station 32 to operate and perform work, converting the electrical energy provided by the battery pack 5 into hydraulic energy. The resulting continuous hydraulic driving force is transmitted to the hydraulic cylinder 33, which then converts the hydraulic energy into mechanical energy, pushing the lifting arm 2 to complete the upward lifting action.

[0024] To achieve automatic overload protection for the electric jack, based on the aforementioned basic structure, the electric jack of this invention also includes a detection module (not shown in the figure), a control module 4, and an alarm module (not shown in the figure). These three components work together to form a complete overload detection, judgment, protection, and warning system. The detection module adopts an integrated sensor module design, directly embedded in the end cover of the motor 31, with the detection end of the module aligned directly with the rotor shaft of the motor 31. This improves the accuracy and real-time performance of parameter detection, providing reliable data support for subsequent overload judgment.

[0025] The detection modules are associated with motor 31, pump station 32, and hydraulic cylinder 33 respectively, and can detect their respective operating parameters in real time and generate detection signals. Specifically, the detection module is electrically connected to motor 31 to detect the operating speed and operating current of motor 31 in real time; for pump station 32, the detection module uses the hydraulic circuit pressure difference as the core operating parameter for real-time monitoring; for hydraulic cylinder 33, the detection module uses the working pressure as the core operating parameter for real-time monitoring. The detection modules convert all collected operating parameter information into detection signals in the form of electrical signals in real time and continuously transmit them to control module 4, realizing full-domain monitoring of the operating status of motor 31, pump station 32, and hydraulic cylinder 33, so that overload judgment can cover various operating conditions of the core drive components of the equipment.

[0026] Control module 4, as the control core of the entire overload protection system, is located on one side of motor 31 (e.g., Figure 3 (As shown in the diagram). The control module 4 is electrically connected to the detection module, motor 31, and alarm module, and undertakes the core functions of receiving detection signals, determining overload logic, and outputting various control signals. The control module 4 internally stores the corresponding operating parameter thresholds for motor 31, pump station 32, and hydraulic cylinder 33. For motor 31, the core power source, it also stores motor overload classification thresholds. The motor overload classification thresholds include a first-level warning threshold and a second-level shutdown threshold, each corresponding to the operating speed threshold and operating current threshold of motor 31. Through differentiated threshold settings, the overload state of motor 31 can be classified and controlled, making overload protection more closely aligned with the actual operating conditions of the equipment, thereby improving the flexibility and adaptability of equipment use.

[0027] During equipment operation, the control module 4 receives and analyzes the detection signals transmitted by the detection module in real time, extracting the real-time detection parameters of the motor 31, pump station 32, and hydraulic cylinder 33. The control module 4 then compares the detection parameters of each component with pre-stored corresponding operating parameter thresholds, forming an overload judgment logic based on multi-component full-domain monitoring. When the detection parameter of any of the motor 31, pump station 32, or hydraulic cylinder 33 exceeds the corresponding operating parameter threshold, the control module 4 immediately determines that the component is in an overload condition. At this time, it simultaneously triggers overload protection and alarm prompts. Through the full-domain monitoring of the detection module and the rapid judgment of the control module 4, the equipment can respond promptly to the overload condition of any core component, ensuring that the drive component 3 receives effective overload protection in various lifting operation scenarios, avoiding equipment failure due to the failure to identify the overload of a single component (e.g., Figure 4 As shown in the image).

[0028] For overload determination of motor 31, control module 4 also has a built-in comprehensive dynamic overload determination model for motor, which breaks through the limitation of determination based on single parameter comparison and realizes dynamic quantitative determination of the overload state of motor 31. The determination formula of this model is: ; in, This represents the combined dynamic overload value of the motor. This is the real-time operating current of motor 31; This is the rated operating current of motor 31; This refers to the real-time operating speed of motor 31; This refers to the rated operating speed of motor 31; This is the current overload weighting coefficient, with a value range of 0.6 ≤ ≤0.8, This is the overload weighting coefficient for rotational speed, with a value range of 0.2 ≤ ≤0.4, and satisfy + The weight allocation principle is 1; This is the overload trend time amplification factor, with a value range of 0.02s. -1 ≤ ≤0.05s -1 , This refers to the duration for which the detected data continuously exceeds the corresponding Level 1 warning threshold.

[0029] Furthermore, the control module 4 pre-stores an overload comprehensive value S1 that matches the first-level warning threshold and an overload comprehensive value S2 that matches the second-level shutdown threshold, and satisfies the numerical relationship 0 < S1 < S2. When the dynamic overload comprehensive value of the motor obtained by the model is in the range of S1 < S < S2, the control module 4 determines that the motor 31 is in a slightly overloaded state. At this time, it outputs a speed reduction control signal to regulate the motor 31 to reduce its operating speed. By reducing the power output, it alleviates the load pressure of the entire hydraulic system, avoids triggering shutdown protection with slight load fluctuations, and ensures the normal lifting operation rhythm of the equipment.

[0030] Based on the aforementioned comprehensive dynamic overload value S of the motor, control module 4 also constructs a hydraulic load adaptive speed reduction control model to achieve precise matching and control between the motor speed 31 and the actual load of the hydraulic system. This allows the speed reduction operation under slight overload conditions to better match the actual hydraulic load of the equipment. The control formula of this model is: ; in, The adaptive target speed reduction of motor 31; The basic speed reduction factor has a value range of 0.3 ≤ ≤0.5; The real-time differential pressure of the hydraulic circuit of pump station 32; This is the rated working pressure difference of pump station 32. Furthermore, to ensure the basic operation and adjustment effectiveness of the hydraulic system, control module 4 sets a minimum speed limit for the speed reduction of motor 31, with a minimum reduction speed not lower than 0.4n0. This avoids problems such as jamming and unstable power output in the hydraulic system due to excessively low speed. While relieving the load pressure on the hydraulic system, it ensures the normal operation of the equipment's hydraulic system, achieving a dual balance between equipment protection and normal operation.

[0031] When the speed detection data of motor 31 is lower than the speed threshold corresponding to the secondary shutdown threshold, or the working current detection data is greater than the current threshold corresponding to the secondary shutdown threshold, or when the comprehensive value of motor dynamic overload S calculated by the motor dynamic overload comprehensive judgment model is greater than or equal to S2, the control module 4 determines that motor 31 is in a heavy overload state. Combined with the multi-component full-domain monitoring judgment logic, when the hydraulic circuit pressure difference of pump station 32 exceeds the corresponding threshold and the working pressure of hydraulic cylinder 33 exceeds the corresponding threshold, the control module 4 determines that the corresponding component is in an overload condition. Regardless of whether any of the components—motor 31, pump station 32, or hydraulic cylinder 33—is overloaded, the control module 4 will immediately and synchronously output two control signals. One signal is a power-off control signal, which, upon transmission to motor 31, directly cuts off the power supply circuit of motor 31, causing motor 31 to stop running. This directly terminates the overload work from the power source, preventing the overloaded component from continuing to operate and avoiding further damage to the equipment. The other signal is an alarm control signal, which, upon transmission to the alarm module, triggers it to issue an overload alarm. This synchronizes overload protection and alarm notification, allowing operators to be aware of the overload situation immediately while the equipment is being protected, providing clear guidance for timely response measures.

[0032] The alarm module, serving as the audible and visual alert unit of the overload protection system, is electrically connected to the control module 4. The alarm module includes two alerting components: a buzzer and an indicator light. Both the buzzer and indicator light are independently electrically connected to the control module 4. When the control module 4 outputs an alarm control signal, it simultaneously triggers two audible and visual alarm actions: first, it controls the buzzer to continuously sound, transmitting overload warning information to the surrounding area; second, it controls the indicator light to flash at high frequency, providing a visual alert to clearly inform on-site operators of the equipment's overload status. This combined audible and visual alarm method is not limited by the on-site working environment, enabling effective overload alerts in various lifting operation scenarios, facilitating operators to quickly take subsequent measures such as unloading heavy objects and stopping the equipment for inspection.

[0033] Finally, it should be noted that the overload warning electric jack of the present invention is applicable to undercarriage lifts, cranes, presses, elevators and hydraulic supports, and can also be adapted to composite equipment formed by combining any one or more of the above-mentioned devices. The application scenarios of the present invention are not limited to the equipment types listed above.

[0034] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An overload warning electric jack, comprising a frame, a lifting arm, and a drive component; the lifting arm and the drive component are both mounted on the frame, and the lifting arm is controlled by the hydraulic driving force of the drive component; The drive components include a motor, a pump station, and a hydraulic cylinder; the motor drives the pump station to perform work and generate hydraulic driving force; the hydraulic cylinder, under the action of the hydraulic driving force, pushes the lifting arm to complete the lifting action; Its features are, It also includes an alarm module; when any of the motor, the pump station, or the hydraulic cylinder experiences an abnormal overload, the alarm module is triggered and issues an overload alarm prompt. At the same time, the motor, the pump station, and the hydraulic cylinder receive a stop operation command.

2. The overload warning electric jack according to claim 1, characterized in that, The alarm module includes a buzzer and an indicator light; when any of the motor, the pump station, or the hydraulic cylinder experiences an abnormal overload, the buzzer will sound continuously, and at the same time, the indicator light will flash at a high frequency.

3. The overload warning electric jack according to any one of claims 1-2, characterized in that, It also includes a detection module and a control module; The detection module is associated with the motor, the pump station, and the hydraulic cylinder respectively, and is used to detect the operating parameters of the motor, the pump station, and the hydraulic cylinder in real time and generate detection signals. The control module is electrically connected to the detection module, the motor, and the alarm module respectively, and pre-stores the corresponding operating parameter thresholds for the motor, the pump station, and the hydraulic cylinder. After receiving the detection signal, the control module compares the detection parameters of the motor, the pump station, and the hydraulic cylinder with the corresponding operating parameter thresholds. When any of the detection parameters of the motor, the pump station, and the hydraulic cylinder exceeds the corresponding operating parameter threshold, it is determined that the motor is in an abnormal overload condition.

4. The overload warning electric jack according to claim 3, characterized in that, The detection module is electrically connected to the motor and is used to detect the motor's operating speed and operating current in real time; the operating parameter of the pump station is the hydraulic circuit differential pressure; the operating parameter of the hydraulic cylinder is the operating pressure.

5. The overload warning electric jack according to claim 4, characterized in that, The detection module is an integrated sensing module; the detection module is embedded in the end cover of the motor, and its detection end is positioned relative to the rotor shaft of the motor.

6. The overload warning electric jack according to claim 4, characterized in that, The control module has pre-stored motor overload classification thresholds; the motor overload classification thresholds include a first-level warning threshold and a second-level shutdown threshold that correspond one-to-one with the motor's operating speed and operating current thresholds; When the motor speed detection data is between the corresponding first-level warning threshold and the second-level shutdown threshold, or when the operating current detection data is between the corresponding first-level warning threshold and the second-level shutdown threshold, the control module outputs a speed reduction control signal to regulate the motor to reduce its operating speed. When the motor speed detection data is lower than the speed threshold corresponding to the secondary shutdown threshold, or the operating current detection data is greater than the current threshold corresponding to the secondary shutdown threshold, the control module outputs a power-off control signal to cut off the power supply to the motor and triggers the alarm module.

7. The overload warning electric jack according to claim 6, characterized in that, The control module incorporates a comprehensive dynamic overload judgment model for the motor, enabling dynamic quantitative judgment of motor overload. The formula is as follows: ； Where S is the comprehensive value of dynamic overload of the motor; This refers to the real-time operating current of the motor. This refers to the rated operating current of the motor. This refers to the real-time operating speed of the motor. The rated operating speed of the motor; For current overload weighting, 0.6 ≤ ≤0.8, For speed overload weighting coefficient, 0.2≤ ≤0.4, and + =1; The overload trend time amplification factor is 0.02s. -1 ≤γ≤0.05s -1 , The duration for which the detected data continuously exceeds the corresponding Level 1 warning threshold; The control module pre-stores an overload comprehensive value S1 that matches the first-level warning threshold and an overload comprehensive value S2 that matches the second-level shutdown threshold, and 0 < S1 < S2; when S1 < S < S2, the control module is triggered to output a speed reduction control signal; when S ≥ S2, the control module is triggered to output a power-off control signal and trigger the alarm module.

8. The overload warning electric jack according to claim 7, characterized in that, The control module constructs an adaptive speed reduction control model for hydraulic load based on the comprehensive value S of motor dynamic overload, realizing the matching control of motor speed and hydraulic load. The formula is as follows: ； in, The adaptive target speed reduction for the motor; k is the basic speed reduction coefficient, 0.3≤k≤0.5; This refers to the real-time differential pressure in the hydraulic circuit of the pump station. The rated operating pressure differential of the pumping station; the control module limits the minimum speed reduction of the motor to no less than 0.

4. .

9. The overload warning electric jack according to claim 7, characterized in that, Suitable for undercarriage lifts, cranes, presses, elevators, and hydraulic supports.

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