A linear actuator with a contact safety nut and a fault detection method

Abstract

The present invention relates to the technical field of aerial work platforms, and particularly relates to a linear actuator with a contact safety nut and a fault detection method. The linear actuator includes a central screw, a transmission nut mechanism, a safety nut mechanism, and a transmission control assembly; the central screw has a spiral raceway, the safety nut mechanism includes a safety nut seat sleeved around the central screw, a limiting hole channel pointing to the central screw is formed on the safety nut seat, an elastic buffer is arranged in the limiting hole channel, a safety ball is arranged between the elastic buffer and the central screw, part of the safety ball falls in the spiral raceway and part is located in the limiting hole channel, and the safety ball can roll along the spiral raceway and can move along the limiting hole channel; the transmission control assembly includes a motor for driving the central screw to rotate and a motor controller for controlling the operation of the motor, and the motor controller can directly receive an external operation state signal and parse it into an action instruction to control the operation of the motor.

Description

Technical Field

[0001] The present invention relates to the technical field of aerial work platforms, and more particularly to a linear actuator with a contact safety nut and a fault detection method. Background Art

[0002] Linear actuators are currently widely used in various fields, including medical equipment, home office, solar power generation, etc. The structure of such a linear actuator generally includes a drive motor, a transmission lead screw, a worm gear, and a transmission nut. The drive motor drives the rotation of the lead screw, and when the lead screw rotates, it drives the axial movement of the transmission nut. The transmission nut can be connected to the driven object to achieve the driving purpose. During operation, the linear actuator not only needs to withstand axial forces but also certain lateral forces, which may cause the transmission nut to be damaged due to abnormal wear and material defects, resulting in a sudden drop, posing a greater risk. To improve the safety performance during use, safety nuts are provided in the transmission nuts of many linear actuators. The safety nut is not designed to keep the push rod running after the thread or ball of the transmission nut is damaged, but only to allow the push rod to descend to a safe position. When the transmission nut is operating normally, the safety nut is ineffective, so the safety nut usually does not engage with the lead screw at this time; when the transmission nut is damaged during the upward movement, the linear actuator will not continue to rise but will rotate in place. If the motor rotates in reverse, the safety nut can be used to drive the linear actuator back to a safe position.

[0003] Since the safety nut engages with the lead screw only when the lead screw fails and comes into play, the safety nut is inoperative during the normal operation of the lead screw lift. Thus, the safety nut does not engage with the lead screw and does not affect the normal operation of the lead screw lift. For example, a lifting device disclosed in the patent with the publication number CN113840794A includes a central screw, a main nut mechanism, and an auxiliary nut mechanism. The main nut mechanism engages with the central screw, and the auxiliary nut mechanism disengages from the central screw. In the event of a failure of the main nut mechanism, the auxiliary nut mechanism is configured to engage with the central screw to prevent the lifting device from descending rapidly and causing danger. Then, the lift controller is configured to allow the work platform to descend to the stowed or transport position to allow workers or operators to safely leave the vehicle. The auxiliary nut mechanism in this patent can engage with the central screw in the event of a failure of the main nut mechanism to ensure safety. However, when the main nut mechanism is operating normally, the auxiliary nut mechanism is always disengaged from the central screw. Therefore, a relatively violent impact will occur at the moment when the auxiliary nut mechanism engages with the central screw, which may cause damage to the central screw and the auxiliary nut mechanism, and will also cause relatively violent vibration of the actuator, and the lifted platform will also vibrate, endangering the safety of the personnel on the platform. In addition, after the auxiliary nut mechanism takes effect, the lifting device does not directly remain stationary at the current position waiting for repair. The actuator still needs to operate to complete the current lifting task or at least descend to a safe height. The auxiliary nut mechanism and the central screw are engaged through a helical thread, specifically approaching and engaging with each other along the axial direction of the central screw. Although the original gap is not large, the engagement will still cause an obvious position error of the actuator in the axial direction of the central screw, resulting in a large error in the entire lift control. In addition, the fault detection method in this patent has a low integration level. Summary of the Invention

[0004] The present invention makes improvements to address the problems existing in the above-mentioned prior art. That is, the technical problem to be solved by the present invention is to provide a linear actuator with a contact-type safety nut, which includes a central screw, a transmission nut mechanism, a safety nut mechanism, and a transmission control assembly; the central screw has a spiral raceway, the safety nut mechanism includes a safety nut seat sleeved around the periphery of the central screw, a limiting hole channel pointing to the central screw is provided on the safety nut seat, an elastic buffer is arranged in the limiting hole channel, a safety ball is arranged between the elastic buffer and the central screw, part of the safety ball falls into the spiral raceway and part is located in the limiting hole channel, and the safety ball can roll along the spiral raceway and can move along the limiting hole channel; the transmission control assembly includes a motor for driving the central screw to rotate and a motor controller for controlling the operation of the motor, and the motor controller can directly receive an external operation state signal and parse it into an action instruction to control the operation of the motor. The elastic buffer and the safety ball of the present invention form an elastic ball mechanism, and the safety nut mechanism always maintains engagement with the central screw through the elastic ball mechanism. The transmission nut mechanism is, for example, a traditional ball screw nut, which converts the rotational actuation of the central screw into a translational motion. In the normal working state where the transmission nut mechanism does not fail, compared with the prior art where the safety nut mechanism is disengaged from the central screw at this time, the safety nut mechanism of this patent always maintains elastic engagement with the central screw through a specially constructed elastic ball mechanism, that is, the meaning of a contact-type safety nut. When the transmission nut mechanism fails, the elastic ball mechanism does not affect the engagement of the safety nut mechanism with the central screw.

[0005] As a preference of the present invention, the inner wall of the safety nut seat has spiral top teeth, and the spiral top teeth extend into the spiral raceway and are spaced apart from the central screw.

[0006] As a preference of the present invention, it further includes a height sensor for monitoring the height value of the platform, a weight sensor for monitoring the weight value of the platform, and a current sensor for monitoring the current value of the motor. A calibration database of the height value, weight value, and current value in comparison is stored in the motor controller, and the motor controller can obtain the monitoring data of the height sensor, the weight sensor, and the current sensor in real time and determine whether the real-time current value exceeds the calibrated current value.

[0007] As a preference of the present invention, the motor controller has a standard current value calculation module. In the self-balanced state, the calculation module can calculate the corresponding standard current value according to the height value and weight value of the current platform, and determine whether the real-time current value is lower than the standard current value.

[0008] Preferably, in the present invention, the height sensor, the weight sensor, and the current sensor are all connected to the motor controller through wires.

[0009] Preferably, in the present invention, the motor controller has a wireless communication conversion module capable of receiving and parsing external operation status signals.

[0010] Preferably, in the present invention, a warning light is further included, and when the motor controller determines that the safety nut mechanism is effective, it can control the warning light to flash.

[0011] Preferably, in the present invention, a remote terminal for communicating with the cloud server through the network is further included. The motor controller can send a fault code to the remote terminal, and the remote terminal is used to transmit the fault code to the cloud server.

[0012] Preferably, in the present invention, when the linear driver performs a free fall action, the motor reverses and converts kinetic energy into electrical energy.

[0013] A fault detection method for a linear driver with a contact safety nut includes the following steps:

[0014] S01: The motor controller directly receives an external operation status signal and parses it into an action instruction capable of controlling the motor.

[0015] S02: Control the operation of the motor according to the parsed action instruction.

[0016] S03: If the action instruction is to rise or fall, the motor operates to make the linear driver perform a rising or falling action. At the same time, the motor controller continuously judges whether the real-time current value monitored exceeds the calibrated current value corresponding to the height value and weight value of the current platform in the database. If the real-time current value does not exceed the calibrated current value, the linear driver continues to perform the rising or falling action.

[0017] S04: If at a certain moment during the rising or falling action, the motor controller determines that the real-time current value monitored exceeds the calibrated current value corresponding to the height value and weight value of the current platform in the database, the motor controller controls the motor to change the output power to make the linear driver stop rising or stop falling and maintain at the current height.

[0018] S05: The linear driver enters the self-balancing state. The motor controller calculates the standard current value for maintaining the self-balancing state based on the height value and weight value of the current platform, and simultaneously determines in real time whether the monitored real-time current value is lower than the calculated standard current value for maintaining the self-balancing state. If the real-time current value is not lower than the standard current value, it is determined that the safety nut is not effective, and the motor controller controls the motor to continue executing the initial upward or downward action instruction.

[0019] S06: If the real-time current value is lower than the standard current value in the self-balancing state, the motor controller determines that the safety nut mechanism is effective.

[0020] S07: If the initial action instruction is upward, the motor controller stops the linear driver from rising, and the motor maintains the current state of the linear driver. If the action instruction is downward, the motor controller stops the motor from running, and the brake of the motor is released. The linear driver descends freely, and at the same time drives the motor to reverse, realizing the energy recovery of the motor.

[0021] S08: The motor controller controls the alarm light to flash and sends the fault code to the remote terminal. The remote terminal transmits the fault code to the cloud server, and the cloud server notifies the after-sales personnel through a wireless signal.

[0022] Beneficial effects:

[0023] The design of the contact-type safety nut enables the linear driver to always maintain safety, stability, and no loss of precision during the conversion process when the transmission nut mechanism fails and the safety nut mechanism intervenes to play a role. The motor controller has a micro-control unit (MCU) and integrates the functions of the vehicle controller (VCU). It can directly receive and analyze the operation status signal of the handle. In this way, the vehicle controller (VCU) is directly cancelled on the hardware, reducing costs, improving integration, reducing complex wiring, reducing the failure rate, and having higher efficiency and precision in fault detection. Description of the drawings

[0024] Figure 1 It is a three-dimensional structural schematic diagram of the transmission nut mechanism and the safety nut mechanism installed on the central screw.

[0025] Figure 2 It is a schematic diagram of the safety nut seat and the central screw.

[0026] Figure 3 For Figure 1 The sectional view of

[0027] Figure 4 For Figure 3The schematic diagram of the plunger and the elastic buffer is omitted;

[0028] Figure 5 It is a schematic diagram where the outlet of the limiting hole passage is located on the spiral top tooth;

[0029] Figure 6 It is a schematic diagram where the outlets of all the limiting hole passages are arranged on the spiral top tooth along the spiral extension direction of the spiral top tooth;

[0030] Figure 7 It is a flowchart of the fault detection method;

[0031] Figure 8 It is a schematic diagram of the overall structure of the scissor lift device;

[0032] Figure 9 It is a schematic diagram when the hydraulic buffer is working;

[0033] Figure 10 It is a schematic diagram of the structure of the hydraulic buffer;

[0034] Figure 11 It is a schematic diagram of the lower connection end;

[0035] Figure 12 It is a schematic diagram of the upper connection end;

[0036] In the figure: 1. Central screw, 11. Spiral raceway, 2. Transmission nut mechanism, 3. Safety nut mechanism, 31. Safety nut seat, 32. Limiting hole passage, 33. Elastic buffer, 34. Safety ball, 35. Spiral top tooth, 36. Plunger, 37. Transfer hole passage, 38. Oil replenishing cavity; 4. Scissor mechanism, 41. Horizontal support rod, 42. Scissor frame, 5. Hydraulic buffer, 51. Hydraulic cylinder, 52. Piston rod, 53. Dust cover, 6. Lower connection end, 61. Lower arc seat, 62. Lower arc groove, 63. Lower opening and closing part, 64. Mounting plate, 7. Upper connection end, 71. Upper arc seat, 72. Upper arc groove, 73. Upper opening and closing part, 81. Lower fastener, 82. Upper fastener, 9. Lifting mechanism. Specific embodiments

[0037] The following specific embodiments are only explanations of the present invention, and they do not limit the present invention. Those skilled in the art can make modifications without creative contributions to this embodiment as needed after reading this specification, but as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

[0038] Embodiment 1:

[0039] A linear actuator with a contact-type safety nut according to the present invention includes a central screw 1, a transmission nut mechanism 2, and a safety nut mechanism 3. The central screw 1 has a spiral raceway 11. The safety nut mechanism 3 includes a safety nut seat 31 sleeved around the periphery of the central screw 1. There is no contact between the safety nut seat 31 and the central screw 1. A limiting hole 32 pointing to the central screw 1 is formed in the safety nut seat 31. An elastic buffer 33 is arranged in the limiting hole 32. A safety ball 34 is arranged between the elastic buffer 33 and the central screw 1. One end of the elastic buffer 33 away from the safety ball 34 can be supported. Specifically, it can be fixedly connected to the inner wall of the limiting hole 32, or the end of the limiting hole 32 away from the central screw 1 is blocked and has a bottom surface, and the elastic buffer 33 directly abuts against this bottom surface. Part of the safety ball 34 falls into the spiral raceway 11 and part is located in the limiting hole 32. The safety ball 34 can roll along the spiral raceway 11 and can move along the limiting hole 32. The safety ball 34 is in complete fit with the spiral raceway 11, and the safety ball 34 can roll smoothly in the spiral raceway 11. When the linear actuator operates normally, the transmission nut mechanism 2 plays a main transmission role. The safety nut mechanism 3 does not function but still needs to move along with the transmission nut. Only the safety ball 34 in the safety nut mechanism 3 falls into the spiral raceway 11 of the central screw 1 and can roll along the spiral raceway 11. The rest of the components in the safety nut mechanism 3 do not contact the central screw 1, but the safety nut mechanism 3 is engaged with the central screw 1 through the safety ball 34. The safety ball 34 is located between the elastic buffer 33 and the central screw 1. When an external force is applied, the safety ball 34 can overcome the elastic force of the elastic buffer 33 and move in the limiting hole 32. Therefore, the safety ball 34 is not tightly pressed in the spiral raceway 11 and only rolls along the spiral raceway 11. Therefore, the presence of the safety ball 34 does not affect the normal operation of the transmission nut mechanism 2.When the transmission nut mechanism 2 fails, it is usually due to the loss of balls in the transmission nut mechanism 2; at this time, along the axial direction of the central screw 1, the safety balls 34 in the safety nut mechanism 3 tightly press against the side wall of the spiral raceway 11. Since the safety balls 34 themselves are completely fitted with the spiral raceway 11, there is no axial displacement of the safety balls 34. At the moment of taking effect, there is no violent impact between the safety balls 34 and the central screw 1, ensuring the stability of the entire linear actuator and avoiding damage to the safety balls 34 and the central screw 1; and part of the safety balls 34 are located in the limiting hole channels 32, so the axial displacement of the safety nut seat 31 can be restricted by clamping the limiting hole channels 32. In this way, the safety nut mechanism 3 will not cause a position error of the linear actuator in the axial direction during operation, and the safety balls 34 also play the role of replacing the lost balls in the transmission nut mechanism 2 and temporarily play a transmission role. In this way, the linear actuator can still complete the current lifting task or descend to a safe height. In short, it can still ensure the operation accuracy, and there is no need to re-check the accuracy when replacing the transmission nut mechanism 2 later. In the lateral direction perpendicular to the axial direction of the central screw 1, the safety nut seat 31 presses towards the central screw 1, and the safety balls 34 will move into the limiting hole channels 32 against the elastic force of the elastic buffer 33. The elastic buffer 33 plays a buffering role to avoid violent vibration of the safety nut mechanism 3 and the linear actuator, ensuring the safety of the lifting equipment. However, in this direction, the safety balls 34 cannot tightly press in the spiral raceway 11, and the safety nut seat 31 directly presses on the central screw 1, playing the role of locking the central screw 1 by the safety nut mechanism 3 to ensure safety. In short, the design of the contact type safety nut enables the linear actuator to always maintain safety, stability and no loss of accuracy during the conversion process when the transmission nut mechanism 2 fails and the safety nut mechanism 3 intervenes and takes effect.

[0040] In this embodiment, the limiting hole 32 points to the central screw 1. Specifically, the extending direction of the limiting hole 32 is perpendicular to the axial direction of the central screw 1. There is only one safety ball 34 in each limiting hole 32 of the safety nut mechanism 3. Therefore, to ensure the overall effect of the safety nut, in this embodiment, it is preferred that a plurality of the limiting holes 32 are arranged circumferentially on the safety nut seat 31, and the elastic buffer 33 and the safety ball 34 are arranged in each limiting hole 32. In this embodiment, the safety nut mechanism 3 mainly relies on the direct extrusion of the safety nut seat 31 and the central screw 1 to resist the lateral force and play a locking role. However, the inner wall of the safety nut seat 31 and the central screw 1 are in smooth contact. If the lateral force is small, the locking effect is average, and the locking effect in the axial direction is very average. Therefore, in this embodiment, it is preferred that the inner wall of the safety nut seat 31 has a spiral top tooth 35. The spiral top tooth 35 extends into the spiral raceway 11 and is spaced apart from the central screw 1. When the transmission nut mechanism 2 operates normally, the spiral top tooth 35 does not contact the central screw 1. When the transmission nut mechanism 2 fails, the safety ball 34 still plays the above role, and the safety nut seat 31 no longer directly presses against the central screw 1, but presses against the spiral raceway 11 of the central screw 1 through the spiral top tooth 35. In this way, the spiral top tooth 35 can directly press against the central screw 1 laterally, and the locking effect is good. At the same time, it can also share the burden of the safety ball 34 axially, ensuring the strength and reliability of the safety nut mechanism 3.

[0041] When the transmission nut mechanism 2 operates normally, the safety ball 34 is not tightly pressed in the spiral raceway 11 and rolls in the spiral raceway 11, so it will not have a great impact on the normal operation of the transmission nut mechanism 2. However, the friction between the safety ball 34 and the spiral raceway 11 will still have a slight impact on the normal operation of the transmission nut mechanism 2, especially the operating efficiency, accuracy, and energy consumption. Therefore, in this embodiment, it is preferred that the limiting hole 32 is filled with oil. The cross-sectional diameter of the limiting hole 32 is the same as the diameter of the safety ball 34. The outer circle of the safety ball 34 completely abuts against the inner wall of the limiting hole 32. The safety ball 34 can effectively block the limiting hole 32 to limit the effect of the safety nut seat 31. The movement of the safety ball 34 in the limiting hole 32 is fully restricted by the limiting hole 32, which is very stable. And the safety ball 34 blocks the limiting hole 32 to prevent the oil from flowing out of the limiting hole 32 directly. The oil is in direct contact with the surface of the safety ball 34, and the safety ball 34 with oil on its surface rolls in the spiral raceway 11. The oil plays a lubricating role, reducing the friction between the safety ball 34 and the spiral raceway 11, and further reducing the impact of the safety nut mechanism 3 on the normal operation of the transmission nut mechanism 2. In addition, the oil in the limiting hole 32 can also play a certain buffering role for the safety ball 34, further improving the shock absorption effect.

[0042] For further improvement, in this embodiment, it is preferred that the limiting hole 32 penetrates through the inner and outer side walls of the safety nut seat 31. The safety ball 34 plugs the outlet of the limiting hole 32 close to the central screw 1. A plunger 36 is detachably installed at the inlet of the limiting hole 32 away from the central screw 1. The plunger 36 plugs the inlet of the limiting hole 32. The elastic buffer 33 is located between the plunger 36 and the safety ball 34. The design that the limiting hole 32 penetrates through and the plunger 36 can facilitate the installation of the elastic buffer 33 and the safety ball 34, and also facilitate the perfusion of oil. During installation, first install the safety nut seat 31, then sequentially place the safety ball 34 and the elastic buffer 33 into the limiting hole 32, then perfusion oil, and finally install the plunger 36 in the inlet of the limiting hole 32 for plugging. The installation is very convenient and it is not necessary to manufacture the elastic buffer 33, the safety ball 34 and the safety nut seat 31 together during production and manufacturing, reducing the manufacturing cost and maintenance cost. During use, the oil will continue to be lost. When it is necessary to add oil, remove the plunger 36, then supplement and perfusion the oil, and then install the plunger 36 and continue to use. Preferably, the connection between the plunger 36 and the limiting hole 32 is a threaded connection.

[0043] The spiral top tooth 35 effectively improves the locking ability of the safety nut mechanism 3. However, in actual operation, when the safety nut mechanism 3 is in effect, the linear actuator still needs to run to complete the current lifting task or descend to the safe height. Therefore, under the action of the driving force, the spiral top tooth 35 on the safety nut mechanism 3 needs to be able to slide along the spiral raceway 11 to realize the advancement of the safety nut mechanism 3. In this embodiment, it is preferred that there is a gap between the safety nut seat 31 and the transmission nut mechanism 2 to form an oil replenishing cavity 38. The oil replenishing cavity 38 surrounds the central screw 1. A transfer hole 37 communicating the limiting hole 32 and the oil replenishing cavity 38 is provided in the safety nut seat 31. When perfusion oil, the limiting hole 32, the transfer hole 37 and the oil replenishing cavity 38 are all filled with oil. The oil in the oil replenishing cavity 38 directly flows into the spiral raceway 11 of the central screw 1, reducing the friction between the spiral top tooth 35 and the spiral raceway 11, so that the safety nut mechanism 3 can more easily advance along the central screw 1 under the drive of the driving force when it is in effect.

[0044] In this embodiment, it is preferred that the limiting holes 32 are arranged in a circumferential array along the circumference of the safety nut seat 31. This refers to the planar arrangement of the limiting holes 32 from the perspective of the axial direction of the central screw 1. In fact, there may be a spacing between these limiting holes 32 in the axial direction of the central screw 1, and they are not on the same cross-section. In a further improvement of this embodiment, it is preferred that the outlets of all the limiting holes 32 are arranged on the spiral top teeth 35 along the spiral extension direction of the spiral top teeth 35. In this way, all the safety balls 34 are also arranged along the spiral extension direction of the spiral top teeth 35. This enables the safety balls 34 to be combined with the spiral top teeth 35 and play their respective roles together at the same position on the spiral raceway 11, simultaneously achieving locking effects in the axial and lateral directions at the same position and improving the locking effect. In this embodiment, the elastic buffer 33 is a spring. The diameter of the spring is smaller than the diameter of the safety ball 34. There is no need for a connection relationship between the two, and they can interact by directly abutting against each other, which is convenient for installation and has a good force transmission effect.

[0045] An aerial work platform of the present invention includes the linear actuator with a contact safety nut. When the safety nut mechanism 3 in the linear actuator functions, it is safe, stable, and there is no loss of precision, which can ensure that the aerial work platform can still be safe, stable, and have good precision when encountering a failure of the linear actuator. The aerial work platform can be a common aerial work platform such as a scissor-type aerial work platform or an aerial work platform with a loading platform.

[0046] Embodiment Two:

[0047] The linear actuator in Embodiment 1 is mainly used in the whole vehicle of an aerial work platform. When a fault occurs in the linear actuator and the safety nut mechanism comes into effect, to ensure safety, it is necessary to stop working in a timely manner and prompt the operator for maintenance. Therefore, this embodiment is an improvement based on the linear actuator in Embodiment 1. That is, the linear actuator in this embodiment adopts the linear actuator in Embodiment 1, and then components are added on this basis to achieve the fault detection function. Specifically, the linear actuator in this embodiment further includes a transmission control assembly. The transmission control assembly includes a motor that drives the central screw to rotate and a motor controller that controls the operation of the motor. The motor controller can directly receive an external operation status signal and parse it into an action instruction to control the operation of the motor. Currently, the common method in the prior art in this field is to transmit the operation status signal of the handle to the vehicle control unit (VCU). After the vehicle control unit (VCU) parses the operation status signal, it is then transmitted to the micro control unit (MCU) in the motor controller. In this method, the vehicle control unit (VCU) is electrically connected to the handle and the motor controller respectively, so the wiring is complicated. The handle is a button device for the operator to issue instructions such as ascending, descending, and maintaining height. The number of its operation status signals is small, so the function of the corresponding vehicle control unit (VCU) is simple. It is easy to implement these functions in the micro control unit (MCU) of the motor controller in terms of hardware. Therefore, the motor controller in this embodiment has a micro control unit (MCU) and integrates the function of the vehicle control unit (VCU). It can directly receive the operation status signal of the handle and perform parsing, thus directly eliminating the vehicle control unit (VCU) in terms of hardware, reducing costs, improving the integration degree, reducing complicated circuits, and reducing the failure rate. At the same time, the operation status signal sent by the handle is an external operation status signal for the motor controller. Since the operation status signal transmitted from the handle to the motor controller is simple and the handle is directly manually operated by the operator, the handle and the motor controller can be connected by traditional reliable wires to transmit signals, or wireless signal communication can be used to transmit signals.

[0048] When the linear drive is actually used in the whole vehicle of an aerial work platform, the whole vehicle has a platform. In this embodiment, the fault detection of the motor controller is mainly judged by three quantities: the platform height value, the platform weight value, and the motor current value. Therefore, the linear drive of this embodiment further includes a height sensor for monitoring the platform height value, a weight sensor for monitoring the platform weight value, and a current sensor for monitoring the motor current value. The monitoring is carried out in real time during the ascending or descending operation process. The motor controller stores a calibration database in which the height value, the weight value, and the current value are compared. The motor controller can obtain the monitoring data of the height sensor, the weight sensor, and the current sensor in real time and judge whether the real-time current value exceeds the calibrated current value. In the normal operation state, there is a calibrated current value corresponding to the real-time height value and weight value in the calibration database. If the monitored real-time current value exceeds this calibrated current value, it proves that the linear drive is subject to a large additional resistance. It is very likely that the transmission nut mechanism fails and the safety nut mechanism comes into effect. The safety nut mechanism acts on the central screw, resulting in an increase in resistance. However, it cannot be completely determined that it is caused by the activation of the safety nut mechanism.

[0049] Once the situation where the real-time current value is greater than the calibrated current value occurs in the linear drive of this embodiment, the motor controller will control the motor to stop rotating, so that the transmission nut mechanism no longer ascends or descends, but maintains at the current height to avoid danger; the motor stopping rotating means that the main shaft stops rotating, realizing the central screw to stop rotating. Actually, the motor still has power output to maintain the current state. At this time, the linear drive enters the self-balanced state, and a fault detection needs to be carried out again to determine whether the safety nut mechanism has come into effect; therefore, the motor controller in this embodiment has a standard current value calculation module. In the self-balanced state, the calculation module can calculate the corresponding standard current value according to the height value and weight value of the current platform, and judge whether the real-time current value is lower than the standard current value. The standard current value refers to the current value that the motor should reach to maintain the self-balanced state when the safety nut mechanism has not come into effect; if the real-time current value is not lower than the standard current value, it proves that there is no additional resistance, the safety nut mechanism has not come into effect, and the transmission nut mechanism has no fault. The first fault detection carried out during the previous traveling process may have detection deviation due to other factors. In this way, the motor controller controls the motor to rotate to continue to execute the initial action instruction, and the linear drive returns to the normal working state; if the real-time current value is lower than the standard current value, it proves that there is additional resistance, it is determined that the safety nut mechanism has come into effect, and the transmission nut mechanism has a fault.

[0050] In this embodiment, the height sensor, the weight sensor, and the current sensor all need to monitor the device in real time. High requirements are placed on the efficiency of data monitoring, the accuracy, and the efficiency of numerical judgment. It is necessary to minimize the delay. Therefore, in this embodiment, it is preferred that the height sensor, the weight sensor, and the current sensor are all connected to the motor controller through wires, which improves the data transmission efficiency and the numerical judgment efficiency, thereby improving the accuracy of the entire fault monitoring. The operation status signals transmitted from the handle to the motor controller are simple and small in number. The handle is manually operated by the operator. Therefore, it is preferred that the motor controller has a wireless communication conversion module capable of receiving and parsing external operation status signals, reducing the setting of wires, facilitating the manual operation of the operator, and the reliability and speed of wireless communication are also sufficient to meet the transmission of simple operation status signals in the handle.

[0051] If it is proved that the safety nut mechanism is effective according to the above two fault detections, it is determined that the drive nut mechanism has a fault, and the normal operation needs to be terminated and repaired in time. In this embodiment, it is preferred that the linear drive further includes a warning light. When the motor controller determines that the safety nut mechanism is effective, it can control the warning light to flash, informing the on-site operator that a fault has occurred and the working state needs to be terminated. Usually, after the user discovers a fault in the linear drive, they need to notify the after-sales personnel of the manufacturer to come for repair, which causes trouble to the user. To further improve after-sales service, in this embodiment, after-sales is incorporated into the fault detection strategy. It is preferred that the linear drive further includes a remote terminal for communicating with the cloud server through the network. The motor controller can send the fault code to the remote terminal, and the remote terminal is used to transmit the fault code to the cloud server. The cloud server is operated by the manufacturer. After receiving the fault code, it can directly send the detailed information to the after-sales personnel in the nearby area. After receiving the assignment, the after-sales personnel can rush to the user's place for repair in time.

[0052] When the motor controller determines that the safety nut mechanism is effective and controls the linear drive to stop executing the lifting instruction, temporary protection measures are also required; specifically, if the initial action instruction is to rise, the motor controller controls the motor to stop rotating, but the motor still has output power to maintain the current state to ensure the safety of the platform, goods or personnel; if the initial action instruction is to descend, the motor controller stops the motor from running, and the brake of the motor is released. The motor is in a state without output power. Under the drive of an external force, the main shaft of the motor will rotate. In this embodiment, when the motor rotates in reverse, it can convert kinetic energy into electrical energy. Therefore, when the linear drive freely descends and contracts, the motor can achieve energy recovery, and the reverse rotation of the motor will provide resistance to the descending and contracting of the linear drive, avoiding the platform from descending too fast and causing danger.

[0053] The linear driver of this embodiment has a fault detection function, and a set of fault detection methods adapted thereto are derived during actual use. Therefore, a fault detection method for a linear driver with a contact safety nut according to the present invention includes the following steps:

[0054] S01: The motor controller directly receives an external operation status signal and parses it into an action instruction capable of controlling the motor.

[0055] S02: Control the operation of the motor according to the parsed action instruction.

[0056] S03: If the action instruction is to rise or fall, the motor operates to make the linear driver perform a rising or falling action. At the same time, the motor controller continuously judges whether the monitored real-time current value exceeds the calibrated current value corresponding to the height value and weight value of the current platform in the database. If the real-time current value does not exceed the calibrated current value, the linear driver continues to perform the rising or falling action.

[0057] S04: If at a certain moment during the rising or falling action, the motor controller determines that the real-time monitored current value exceeds the calibrated current value corresponding to the height value and weight value of the current platform in the database, the motor controller controls the motor to change the output power to make the linear driver stop rising or stop falling and maintain at the current height.

[0058] S05: The linear driver enters a self-balancing state. The motor controller calculates a standard current value for maintaining the self-balancing state according to the height value and weight value of the current platform, and at the same time continuously judges whether the monitored real-time current value is lower than the calculated standard current value for maintaining the self-balancing state. If the real-time current value is not lower than the standard current value, it is determined that the safety nut has not taken effect, and the motor controller controls the motor to continue to execute the initial rising or falling action instruction.

[0059] S06: If the real-time current value is lower than the standard current value in the self-balancing state, the motor controller determines that the safety nut mechanism has taken effect.

[0060] S07: If the initial action instruction is to rise, the motor controller makes the linear driver stop rising, and the motor maintains the current state of the linear driver. If the action instruction is to fall, the motor controller stops the motor, and the brake of the motor is released. The linear driver freely descends, and at the same time drives the motor to reverse to realize the energy recovery of the motor.

[0061] S08: The motor controller controls the alarm light to flash and sends the fault code to the remote terminal, and the remote terminal transmits the fault code to the cloud server, and the cloud server notifies the after-sales personnel through a wireless signal.

[0062] Embodiment Three:

[0063] A scissor lift device with a hydraulic buffer 5 for maintenance according to the present invention includes a hydraulic buffer 5 and a scissor mechanism 4. The hydraulic buffer 5 includes a hydraulic cylinder 51 and a piston rod 52. The hydraulic cylinder 51 has a lower connection end 6, and the piston rod 52 has an upper connection end 7. After the hydraulic buffer 5 is joined to the scissor mechanism 4 through the upper connection end 7 and the lower connection end 6, it can support the scissor mechanism 4. When using the hydraulic buffer 5 for support, when the scissor mechanism 4 applies pressure to the hydraulic buffer 5, the piston rod 52 will be gradually pressed into the hydraulic cylinder 51. In this process, the characteristics of the hydraulic buffer 5 itself, such as strong buffering ability and strong load capacity, are utilized. When the hydraulic buffer 5 supports the scissor mechanism 4, it is not only safe and stable, but also uses its buffering performance to resist impact, avoiding damage to itself and the scissor mechanism 4. In addition, the maximum load that can be satisfied is relatively large. During actual maintenance, it is even possible to only use the hydraulic buffer 5 for support without starting the lifting mechanism 9 to provide additional support force. During the generally long maintenance process, this can effectively save energy. In this embodiment, the hydraulic buffer 5 has a lower connection end 6 and an upper connection end 7 that are specifically joined to the scissor mechanism 4, and the joining firmness is good, further ensuring safety.

[0064] The scissor mechanism 4 includes two sets of front and rear scissor frames 42 and a cross support rod 41 erected between the two sets of scissor frames 42. The cross support rod 41 is arranged in the vertical direction on the left and right sides of the scissor mechanism 4; when the scissor frames 42 are unfolded, the cross support rods 41 on the same side are far away from each other in the vertical direction, and when the scissor frames 42 are contracted, the cross support rods 41 on the same side are close to each other in the vertical direction; the hydraulic buffer 5 is arranged between two vertically adjacent cross support rods 41 in the middle cross support rod 41 on one side, and is joined to the upper cross support rod 41 through the upper connection end 7 and joined to the lower cross support rod 41 through the lower connection end 6. By supporting these two cross support rods 41, the support for the entire scissor mechanism 4 is realized. The hydraulic buffer 5 may be damaged, and the load capacity required for the hydraulic buffer 5 is different for different actual situations. In both cases, the hydraulic buffer 5 needs to be replaced. Therefore, in this embodiment, the joining form between the lower connection end 6 and the cross support rod 41 is a detachable fixation.

[0065] Regarding the specific engagement form between the hydraulic buffer 5 and the horizontal support rod 41, in this embodiment, it is preferred that the lower connection end 6 includes a lower arc seat 61. The lower arc seat 61 has a lower arc groove 62 that can completely abut against the outer wall of the horizontal support rod 41 to achieve clamping. Both ends of the lower arc seat 61 are rotatably connected with lower opening and closing parts 63. The lower opening and closing parts 63 are arc-shaped and can completely abut against the outer wall of the horizontal support rod 41. The ends of the two lower opening and closing parts 63 are connected with a lower fastener 81, and the lower fastener 81 can pull the ends of the two lower opening and closing parts 63 towards each other to achieve locking. The lower arc seat 61 is an integrally formed part with relatively high self-structural strength and plays a main role in clamping and supporting. The horizontal support rod 41 is a circular rod, and the shape of the lower arc groove 62 fits the shape of the outer wall of the horizontal support rod 41. The lower arc seat 61 semi-encloses the horizontal support rod 41 through the lower arc groove 62, and the clamping relationship is very stable and reliable. The lower opening and closing parts 63 completely hoop the horizontal support rod 41 to further improve the firmness of the engagement. When the lower fastener 81 is locked, it has a force to pull the ends of the two lower opening and closing parts 63 towards each other, so that the two lower opening and closing parts 63 hoop the horizontal support rod 41 tightly. During installation, the two lower opening and closing parts 63 are in an open state. After the lower arc seat 61 is clamped with the horizontal support rod 41, the two lower opening and closing parts 63 are then used to hoop the horizontal support rod 41, and the lower fastener 81 is used for locking.

[0066] If the two ends are in contact after the two lower opening and closing parts 63 hoop the horizontal support rod 41, there is actually interference between them. No matter how much the locking force of the lower fastener 81 is increased, it is difficult to act on the two lower opening and closing parts 63. Therefore, in this embodiment, it is preferred that after the two lower opening and closing parts 63 completely abut against the outer wall of the horizontal support rod 41, there is a gap between the ends of the two lower opening and closing parts 63. In this way, when the locking force of the lower fastener 81 is increased, the clamping force between the lower opening and closing parts 63 and the horizontal support rod 41 can be improved, and the locking effect can be further improved. After locking, it is difficult for the lower connection end 6 to move relative to the horizontal support rod 41, so it can be considered that a fixed state is achieved. The ends of the lower opening and closing parts 63 have mounting pieces 64 for installing the lower fastener 81. The mounting pieces 64 are vertically arranged up and down, and the locking force generated by the lower fastener 81 is perpendicular to the mounting pieces 64. The lower fastener 81 pulls the two mounting pieces 64 to improve the transmission effect of the locking force of the lower fastener 81 and further improve the locking effect. It is preferred that the lower fastener 81 includes a bolt and a nut. Through holes for the bolt to pass through are provided in the mounting pieces 64. The bolt passes through the through holes of the two mounting pieces 64 at the same time, and then the nut is tightened to generate a locking force.

[0067] In this embodiment, the upper connecting end 7 includes an upper arc seat 71, and the upper arc seat 71 has an upper arc groove 72 that can be completely attached to the outer wall of the horizontal support rod 41 to achieve engagement; both ends of the upper arc seat 71 are rotatably connected with an upper opening and closing portion 73, and the upper opening and closing portion 73 is arc-shaped and can be completely attached to the outer wall of the horizontal support rod 41, and the ends of the two upper opening and closing portions 73 are connected with an upper fastener 82, and the upper fastener 82 can pull the ends of the two upper opening and closing portions 73 toward each other to achieve locking. The functions of the upper arc seat 71, the upper opening and closing portion 73 and the upper fastener 82 correspond to the lower arc seat 61, the lower opening and closing portion 63 and the lower fastener 81, respectively, and the installation principle is also the same. Of course, it can be further preferred that there is also a gap between the ends of the two upper opening and closing portions 73 after the horizontal support rod 41 is clamped, and the ends of the two upper opening and closing portions 73 are provided with a mounting piece 64 for the upper fastener 82 to install, so as to better play the locking effect of the upper fastener 82. The composition of the upper fastening member 82 is also the same as that of the lower fastening member 81 .

[0068] The hydraulic buffer 5 is only used when it is used for maintenance. When the scissor-type lifting equipment is working normally, the hydraulic buffer 5 does not work and can be directly removed through the lower connecting end 6 and the upper connecting end 7. However, there is usually no extra space on the equipment for placement, and it must be removed every time after use, which is too cumbersome. Therefore, in this embodiment, it is preferred that a storage box with an upward opening is provided on the side wall of one of the scissor frames 42 facing the other scissor frame 42. When the lower fastener 81 is loosened, the lower connecting end 6 can move along the cross support rod 41 toward the scissor frame 42 with the storage box, and the lower fastener 81 can rotate relative to the cross support rod 41, so that the hydraulic buffer 5 falls into the storage box. When in use, the hydraulic buffer 5 is usually located in the middle of the cross support rod 41 for better support, and the storage box is set on the side wall of the scissor frame 42, which is a directly fixed connection relationship. The closer it is, the higher the firmness, and it can avoid interference with the lifting mechanism 9; so when storing the hydraulic buffer 5, first release the engagement between the upper connecting end 7 and the cross support rod 41, and then loosen the nut in the lower fastener 81 so that the lower opening and closing part 63 no longer clamps the cross support rod 41, and the lower connecting end 6 can move or rotate relative to the cross support rod 41, first move toward the scissor frame 42 with the storage box, until the hydraulic buffer 5 is aligned with the storage box, and then rotate the lower connecting end 6 relative to the cross support rod 41, and the hydraulic buffer 5 falls into the storage box to achieve storage. Furthermore, it is preferred that a detachable cover plate is set at the opening of the storage box. When the hydraulic buffer 5 is stored in the storage box, the cover plate is installed to prevent the hydraulic buffer 5 from detaching from the storage box and affecting the normal operation of the equipment.

[0069] Since the piston rod 52 will enter and exit the hydraulic cylinder 51 when the hydraulic buffer 5 is working, in order to prevent impurities from entering the hydraulic cylinder 51 through the gap and affecting the normal operation of the hydraulic cylinder 51, in this embodiment, the hydraulic buffer 5 preferably also includes a dust cover 53 sleeved on one end of the hydraulic cylinder 51, the dust cover 53 is fixed on the piston rod 52, and the dust cover 53 can follow the piston rod 52 to move relative to the hydraulic cylinder 51, and the dust cover 53 surrounds one end of the hydraulic cylinder 51 in the circumferential direction, is sealed and fixed to the piston rod 52 on one axial side, and is open on the other axial side for the hydraulic cylinder 51 to extend into. In this way, the dust cover 53 can prevent impurities from entering the hydraulic cylinder 51. The hydraulic buffer cylinder has a maximum load capacity. If this load capacity is exceeded, it will be damaged and fail. Therefore, in this embodiment, a warning scale is preferably set on the outer wall of the hydraulic cylinder 51. When the dust cover 53 moves, a visible distance change occurs between its lower edge and the warning scale. When the lower edge of the dust cover 53 reaches the warning scale, the hydraulic buffer 5 reaches the maximum load capacity. When using the hydraulic buffer 5, firstly, the lifting mechanism 9 is used to lift the scissor mechanism 4, so that the distance between the two adjacent horizontal support rods 41 is greater than the total length of the hydraulic buffer 5 in the initial state, and then the hydraulic buffer 5 is lifted up from the storage box, so that the upper arc groove 72 in the upper arc seat 71 of the upper connecting end 7 is aligned with the upper horizontal support rod 41, and then the descending function module of the lifting mechanism 9 is started to drive the scissor mechanism 4 to contract and descend, so that the horizontal support rod 41 enters the upper arc groove 72, and continues to descend so that the hydraulic buffer 5 supports the horizontal support rod 41. In the process of continuing to descend, it is necessary to stop the lifting mechanism 9 from descending in time before the lower edge of the dust cover 53 exceeds the warning scale to avoid damage to the hydraulic buffer 5. In this way, only the scissor mechanism 4 is pressed on the hydraulic buffer 5, which is usually a load that the hydraulic buffer 5 can withstand.

[0070] However, in actual operation, the operator may forget to close the lifting mechanism 9 if he / she is not careful, and the lifting mechanism 9 continues to descend. The hydraulic buffer 5 bears the pressure of the scissor mechanism 4 and the thrust of the lifting mechanism 9. When the lower edge of the dust cover 53 exceeds the warning scale, the hydraulic buffer 5 is damaged. Therefore, in this embodiment, the scissor-type lifting equipment preferably also includes a lifting mechanism 9, a controller and a switch. The lifting mechanism 9 supports the scissor mechanism 4 and has a rising function module and a falling function module that can push the scissor mechanism 4 to extend or contract; the switch is set on the hydraulic buffer 5, and the switch can be triggered when the lower edge of the dust cover 53 reaches the warning scale; the controller can receive the signal of the switch and can control the lifting mechanism 9 to stop the descending action to avoid damage to the hydraulic buffer 5. The lifting mechanism 9 adopts the linear drive with contact safety nut described in the first embodiment.

[0071] Based on the above-mentioned scissor lift equipment with the hydraulic buffer 5 for maintenance, the present invention proposes a control method for the scissor lift equipment with the hydraulic buffer 5 for maintenance, specifically the control method during maintenance, including the following steps:

[0072] S01: Start the rising function module of the lifting mechanism 9 to drive the scissor mechanism 4 to extend until the distance between two adjacent cross struts 41 in the vertical direction exceeds the total length of the hydraulic buffer 5 in the initial state;

[0073] S02: Take out the hydraulic buffer 5 from the storage position and prop it up upward so that the upper connection end 7 of the hydraulic buffer 5 aligns with the cross strut 41 of the scissor mechanism 4;

[0074] S03: Start the descending function module of the lifting mechanism 9 to drive the scissor mechanism 4 to contract, and the cross strut 41 located above the hydraulic buffer 5 and closest to the upper connection end 7 moves toward the upper connection end 7 until it engages with the upper connection end 7;

[0075] S04: The lifting mechanism 9 continues to drive the scissor mechanism 4 to contract, the cross strut 41 squeezes the hydraulic buffer 5, the hydraulic buffer 5 gradually contracts, and the lower edge of the dust cover 53 gradually approaches the warning scale;

[0076] S05: Before the lower edge of the dust cover 53 exceeds the warning scale, turn off the descending function module of the lifting mechanism 9 to stop the contraction of the scissor mechanism 4, and the hydraulic buffer 5 supports the scissor mechanism 4.

[0077] For a further improvement of the above step S05, when the lower edge of the dust cover 53 reaches the warning scale in step S05, the dust cover 53 triggers the switch, and after the controller receives the signal of the switch, it controls the lifting mechanism 9 to turn off the descending function module.

[0078] For a further improvement, there is also step S06 after step S05. After the descending function module of the lifting mechanism 9 is turned off, the controller controls the lifting mechanism 9 to start the rising function module. The supporting force output by the rising function module can, together with the hydraulic buffer 5, maintain the static state of the scissor mechanism 4, reduce the burden on the hydraulic buffer 5, and moreover, even in the extreme case of sudden failure of the hydraulic buffer 5, the lifting mechanism 9 can also play a supporting role to further ensure safety.

[0079] Since the above control method utilizes the hoisting mechanism 9, it is applicable to the situation of repairing components other than the hoisting mechanism 9. If the hoisting mechanism 9 needs to be repaired, another control method is required. A control method for a scissor lift device with a hydraulic buffer 5 for repair includes the following steps:

[0080] S01: Hoist and pull the scissor mechanism 4 upward to extend the scissor mechanism 4 until the distance between two adjacent cross struts 41 in the vertical direction exceeds the total length of the hydraulic buffer 5 in the initial state;

[0081] S02: Take out the hydraulic buffer 5 from the storage position and prop it up upward so that the upper connection end 7 of the hydraulic buffer 5 aligns with the cross strut 41 of the scissor mechanism 4;

[0082] S03: Keep hoisting and pulling the scissor mechanism 4, and gradually lower the scissor mechanism 4 by using the hoisting force to make the scissor mechanism 4 contract. The cross strut 41 located above the hydraulic buffer 5 and closest to the upper connection end 7 moves toward the upper connection end 7 until it engages with the upper connection end 7;

[0083] S04: As the scissor mechanism 4 continues to contract, the hydraulic buffer 5 gradually supports the cross tie rod;

[0084] S05: Remove the hoisting force so that the scissor mechanism 4 is completely supported by the hydraulic buffer 5.

[0085] The hoisting force in this control method is provided by a suspension device.

[0086] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A fault detection method for a linear actuator with a contact safety nut, the linear actuator comprising a central screw (1), a transmission nut mechanism (2), a safety nut mechanism (3), and a transmission control assembly; the central screw (1) has a spiral raceway (11), the safety nut mechanism (3) includes a safety nut seat (31) sleeved around the periphery of the central screw (1), the safety nut seat (31) is provided with a limiting hole (32) pointing to the central screw (1), an elastic buffer (33) is arranged in the limiting hole (32), a safety ball (34) is arranged between the elastic buffer (33) and the central screw (1), part of the safety ball (34) falls in the spiral raceway (11) and part is located in the limiting hole (32), and the safety ball (34) can roll along the spiral raceway (11) and can move along the limiting hole (32); the transmission control assembly includes a motor for driving the central screw to rotate and a motor controller for controlling the operation of the motor, and the motor controller can directly receive an external operation state signal and parse it into an action instruction to control the operation of the motor; The inner wall of the safety nut seat (31) has a spiral top tooth (35), and the spiral top tooth (35) extends into the spiral raceway (11) and is spaced apart from the central screw (1); The linear actuator further includes a height sensor for monitoring the platform height value, a weight sensor for monitoring the platform weight value, and a current sensor for monitoring the current value of the motor, and a calibration database of the corresponding height value, weight value, and current value is stored in the motor controller. The motor controller can obtain the monitoring data of the height sensor, the weight sensor, and the current sensor in real time and determine whether the real-time current value exceeds the calibrated current value; It is characterized in that The method includes the following steps: S01: The motor controller directly receives an external operation state signal and parses it into an action instruction capable of controlling the motor; S02: Control the operation of the motor according to the parsed action instruction; S03: If the action instruction is to rise or fall, the motor operates to make the linear actuator perform a rising or falling action. At the same time, the motor controller continuously determines whether the real-time current value monitored exceeds the calibrated current value corresponding to the height value and weight value of the current platform in the database. If the real-time current value does not exceed the calibrated current value, the linear actuator continues to perform the rising or falling action; S04: If at a certain moment during the rising or falling action, the motor controller determines that the real-time monitored current value exceeds the calibrated current value corresponding to the height value and weight value of the current platform in the database, the motor controller controls the motor to change the output power to make the linear actuator stop rising or stop falling and maintain at the current height; S05: The linear driver enters the self-balancing state. The motor controller calculates the standard current value for maintaining the self-balancing state based on the height value and weight value of the current platform, and simultaneously determines in real time whether the monitored real-time current value is lower than the calculated standard current value for maintaining the self-balancing state. If the real-time current value is not lower than the standard current value, it is determined that the safety nut is not effective, and the motor controller controls the motor to continue executing the initial upward or downward action instruction. S06: If the real-time current value is lower than the standard current value in the self-balancing state, the motor controller determines that the safety nut mechanism is effective. S07: If the initial action instruction is upward, the motor controller stops the linear driver from rising, and the motor maintains the current state of the linear driver. If the action instruction is downward, the motor controller stops the motor from running, and the brake of the motor is released. The linear driver descends freely, and at the same time drives the motor to reverse, realizing the energy recovery of the motor. S08: The motor controller controls the warning light to flash and sends the fault code to the remote terminal. The remote terminal transmits the fault code to the cloud server, and the cloud server notifies the after-sales personnel through a wireless signal.

2. The fault detection method according to claim 1, characterized in that The motor controller has a standard current value calculation module. In the self-balancing state, the calculation module can calculate the corresponding standard current value based on the height value and weight value of the current platform, and determine whether the real-time current value is lower than the standard current value.

3. The fault detection method according to claim 2, wherein The height sensor, the weight sensor, and the current sensor are all connected to the motor controller through wires.

4. The fault detection method according to claim 3, characterized in that The motor controller has a wireless communication conversion module that can receive and analyze external operation status signals.

5. The fault detection method according to claim 4, wherein It also includes a warning light, and the motor controller can control the warning light to flash when it determines that the safety nut mechanism is effective.

6. The fault detection method according to claim 5, wherein, It also includes a remote terminal for communicating with the cloud server through the network. The motor controller can send the fault code to the remote terminal, and the remote terminal is used to transmit the fault code to the cloud server.

7. The fault detection method according to claim 6, wherein When the linear driver descends freely, the motor reverses and converts kinetic energy into electrical energy.

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