A control method of an electric hydraulic jack with safety protection function

Abstract

The application discloses a control method of an electric hydraulic jack with a safety protection function, characterized in that when the jack is controlled to ascend, an ascending button of a positioning button area is pressed, and a main control module controls the jack to ascend; during the ascending process, the motor current and temperature are monitored, when the motor current exceeds the preset current parameter at the time of positioning, the main control module controls the ascending button and the descending button of the positioning button area to be locked, at this time, the ascending button and the descending button of the positioning button area are both invalid; when the jack continues to be controlled to ascend, the ascending button of a safety button area is pressed to control the motor to start, the motor drives the electric pump to start, and the hydraulic oil is pumped into the jack to make the jack continue to ascend. Through the setting of the application, the staff can conveniently operate the electric jack to lift the vehicle or other heavy objects, the jack operation process is monitored and the safety protection function is realized, so that the safety of the electric jack during use is improved, and the safety hidden danger is reduced.

Description

Technical Field

[0001] The present invention relates to an electric hydraulic jack, in particular to a control method of the electric hydraulic jack with a safety protection function. Background Art

[0002] An electric hydraulic jack is a type of jack that uses an electric motor as a power element to drive the jack for lifting. When the jack is lowered, the oil is released by opening the oil release valve, thereby achieving the lifting and lowering functions of the car.

[0003] Among the existing technologies, there are technical solutions that use push-pull electromagnets to drive the opening and closing of the oil drain valve, technical solutions that control the opening and closing of the oil drain valve through a solenoid valve, and solutions that control the rise and fall of the jack by controlling the forward and reverse rotation of the motor and gear pump.

[0004] In the above three control methods, when the operator presses the corresponding button, the main control module controls the corresponding motor, pushes and pulls the electromagnet or solenoid valve to drive the jack to lift and lower.

[0005] In the prior art, electric jacks can be driven by pressing a switch button on a handle, without manual depressing. For safety reasons, the switch on the handle is generally located at the distal end of the jack handle, away from the jack's lifting components, so that the operator maintains a safe distance from the vehicle being lifted. However, in actual vehicle lifting operations, to ensure that the jack's lifting components properly contact the vehicle's lifting points, the operator typically crouches under the vehicle being lifted to closely observe whether the jack is properly contacting the vehicle's lifting points. However, since the operating button of existing electric jacks is located at the distal end of the handle, the operator's arm length is not long enough to observe and operate the handle switch simultaneously. Therefore, the operator must frequently crawl in and out from under the vehicle being lifted, operating the jack while observing whether the jack's lifting components properly contact the vehicle's lifting points. This operation method is time-consuming and labor-intensive, and is inconvenient and unsafe. Therefore, it is necessary to provide the operator with a method for positioning the jack and the vehicle lifting so that the operator can operate the jack while observing that the jack arm can correctly contact the lifting point of the lifted vehicle, while ensuring the operator's personal safety. To this end, a control method for an electro-hydraulic jack with a safety protection function is proposed. Summary of the Invention

[0006] The purpose of the present invention is to solve the above problems and to provide a control method for an electric hydraulic jack with a safety protection function.

[0007] In order to achieve the above object, the present invention provides the following technical solution: a control method for an electric hydraulic jack with a safety protection function, characterized in that:

[0008] When the jack is positioned with the jacked object, the up button of the positioning button area is pressed to send a signal to the main control module, the main control module controls the motor to start, the motor drives the electric pump to start, and the hydraulic oil is pumped into the jack to make it jack up;

[0009] In the positioning and jacking process, the motor current acquisition module collects and monitors the motor current. After the jack contacts the jacked object, the motor current will increase. When the motor current acquisition module collects the motor current exceeding the preset current parameter at the time of positioning, it is fed back to the main control module. The main control module no longer receives the instruction signal of the up button and down button of the positioning button area or no longer outputs the control instruction after receiving the instruction signal of the up button and down button of the positioning button area. At this time, the up button and down button of the positioning button area are temporarily disabled and in a locked state. At this time, if the jack needs to continue to be controlled, the operator must press the up button of the safety button area to send a signal to the main control module. The main control module controls the motor to start, the motor drives the electric pump to start, and the hydraulic oil is pumped into the jack to make it continue to jack up.

[0010] Further preferably, it also includes a control method for controlling the jack to descend through the down button of the positioning button area; which includes when the jack does not contact the jacked object to form lifting, directly press the down button of the positioning button area to send a signal to the main control module, and the main control module controls the electromagnetic iron one to be powered on, thereby opening the oil drain valve to return oil and make the jack descend.

[0011] When the up button and down button of the positioning button area of the jacked object are in a locked state, first press the down button or up button of the safety button area to send an instruction to the main control module. After the main control module receives the instruction and controls the electromagnetic iron one or the motor to work, the up button of the positioning button area is unlocked. Then, continuously press the up button of the positioning button area for a set time. If the motor current exceeds the set current parameter at the time of positioning, the main control module controls the up button of the positioning button area to be locked again. When the current of the motor does not exceed the set current parameter at the time of positioning within the set time, the down button of the positioning button area is unlocked. After unlocking, press the down button of the positioning button area to send a signal to the main control module. The main control module controls the electromagnetic iron one to be powered on, thereby opening the oil drain valve to return oil and make the jack descend.

[0012] Further preferably, the jack is further lifted by controlling the up button in the safety button area, and the motor current acquisition module collects and monitors the motor current. When the motor current exceeds the set value, the main control module controls the motor to suspend operation. After the motor is suspended for a set time, the up button in the safety button area is pressed again to control the jack to rise. If the jack rises normally and the motor current does not exceed the set value, normal operation is performed. If the motor current exceeds the set value again, the main control module continues to control the motor to suspend operation.

[0013] When controlling the jack to descend, by pressing the descend button in the safety button area, a signal is sent to the main control module. The main control module controls the electromagnet to be energized, thereby opening the oil release valve to return oil and lowering the jack.

[0014] Further preferably, the motor temperature during motor operation is collected and monitored by a temperature acquisition module. When the motor temperature acquisition module detects that the motor temperature exceeds a set value, it sends a signal to the main control module. The main control module controls the motor to stop working. The motor can only be started again after the motor temperature is lower than the set value.

[0015] Further preferably, the up button and down button in the positioning button area are set at any position of the jack or on a control terminal that establishes a communication connection with the jack main control module through wired or wireless communication; the up button and down button in the safety button area are set on the handle of the jack and at one end far away from the jack and the object being lifted.

[0016] Further preferably, when controlling the movement of electromagnet 1 to open the oil drain valve and lower the jack, the main control module controls the power supply to electromagnet 1. After electromagnet 1 is energized, it drives the transmission part used to push the oil drain valve to open the oil drain valve to return oil, so that the jack is lowered. Then the main control module controls the power supply to electromagnet 2. After electromagnet 2 is energized, it is magnetically connected to a metal part, so that the transmission part keeps pushing the oil drain valve to the open position. Then the main control module controls the power supply to electromagnet 1.

[0017] Further preferably, the temperature and current of electromagnet 1 and electromagnet 2 are detected in real time during the descent process. When the temperature and current of electromagnet 1 and electromagnet 2 are within the set range, they continue to work normally. When the temperature and current exceed the set range, the main control module controls to cut off the power to electromagnet 1 and electromagnet 2.

[0018] Further preferably, when the single continuous working time of the electromagnet 2 exceeds the set value, the main control module actively cuts off the output and the jack stops descending.

[0019] Further preferably, it also includes a display module controlled by the main control module for displaying the jack status and battery pack status.

[0020] Further preferably, the method of lowering the jack by controlling the electromagnet and the oil drain valve through the main control module is replaced by controlling the solenoid valve through the main control module to switch the oil circuit back to achieve the jack lowering, or by controlling the rotation direction of the motor and gear pump through the main control module to switch the flow direction of the hydraulic oil to achieve the jack lowering.

[0021] The beneficial effects of the present invention are as follows: through the configuration of the present invention, it is convenient for workers to operate the electric jack to lift vehicles or other heavy objects, and at the same time, the operation process of the jack is monitored and safety protection is provided, thereby improving the safety of the electric jack when in use and reducing safety hazards;

[0022] By setting the up button and down button in the positioning button area, the up button is used to drive the jack to rise when it is unloaded, and the down button is used to drive the jack to descend when it is unloaded. The jacking position of the jack is adjusted by the up button and down button in the positioning button area. After the jack contacts the object to be lifted, the up button and down button in the positioning button area are locked after the motor current exceeds the set current parameter for positioning. At this time, the up button and down button locking fail. At this time, the user can only climb out of the object to be lifted or leave the vicinity of the object to be lifted, and then press the up button set in the safety button area after being in a safe position to drive the jack to continue lifting. The up button and down button in the positioning button area can be unlocked only when the up button in the safety button area is pressed and the main control module controls the up button in the positioning button area to unlock. After unlocking, the up button in the positioning button area can be pressed to control the jack to rise.

[0023] Before pressing the down button in the positioning button area to control the jack to descend, you must first keep pressing the up button in the positioning button area for the set time to ensure that the jack is in a no-load state. Only then can you control the jack to descend by pressing the down button in the positioning button area. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the local structure of the jack using the present invention;

[0025] Figure 2 This is a schematic diagram of the first position of the positioning button area and the safety button area in the jack using the present invention;

[0026] Figure 3 This is a schematic diagram of the second position of the positioning button area and the safety button area in the jack of the present invention;

[0027] Figure 4 This is a schematic diagram of the third position of the positioning button area and the safety button area in the jack of the present invention;

[0028] Figure 5This is a schematic diagram of the fourth position of the positioning button area and the safety button area in the jack of the present invention.

[0029] Description of the drawings: 1. Jack; 2. Motor; 3. Electromagnet 1; 4. Transmission part; 5. Electromagnet 2; A. Positioning button area; B. Safety button area. DETAILED DESCRIPTION

[0030] Next, we will further illustrate the control method of the electric hydraulic jack with safety protection function according to the present invention with reference to the accompanying drawings.

[0031] It should be noted that all directional indications in the embodiments of the present invention, such as up, down, left, right, front, back, etc., are only used to explain the relative position relationship, movement status, etc. between the various components in a certain specific posture as shown in the accompanying drawings. If the specific posture changes, the directional indication will also change accordingly.

[0032] In the present invention, unless otherwise specified or limited, the terms "connected" and "fixed" should be understood in a broad sense; they may refer to mechanical or electrical connections, direct or indirect connections through an intermediate medium, and may refer to internal communication between two elements or the interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0033] See Figure 1-Figure 5 As shown in , a control method for an electric hydraulic jack 1 with a safety protection function is characterized by:

[0034] When the jack 1 is moved to the bottom of the object to be lifted for lifting, the operator is located under the object to be lifted and observes the lifting position of the jack 1 and the object to be lifted. The operator first controls the jack 1 to lift without load until the jack 1 contacts the lifting position of the object to be lifted.

[0035] When controlling the positioning of the jack 1 and the object to be lifted, press the rising button in the positioning button area to send a signal to the main control module. The main control module controls the motor to start, and the motor drives the electric pump to start, pumping hydraulic oil into the jack 1 to lift it;

[0036] During the positioning and lifting process, the motor current acquisition module collects and monitors the motor current. After the jack 1 contacts the object being lifted, the motor current will increase. When the motor current acquisition module detects that the motor current exceeds the preset current parameter for positioning, it will feed back to the main control module. Then, the main control module will no longer receive the command signals of the up button and down button in the positioning button area, or will no longer output control commands after receiving the command signals of the up button and down button in the positioning button area. At this time, the up button and down button in the positioning button area are temporarily disabled and in a locked state.

[0037] At this time, if it is necessary to continue to control the lifting of jack 1, the operator must press the up button in the safety button area to send a signal to the main control module. The main control module controls the motor to start, and the motor drives the electric pump to start, pumping hydraulic oil into jack 1 to continue lifting;

[0038] During the lifting process of jack 1, the motor current and temperature are monitored by the motor current acquisition module and the motor temperature acquisition module. When the motor current or temperature exceeds the set value, the control module controls the motor to stop working and controls the display module to light up red.

[0039] When the motor current exceeds the set value, the main control module controls the motor to suspend operation; after the motor suspends operation for the set time, press the up button in the safety button area again to control the jack 1 to rise. If the jack 1 rises normally and the motor current does not exceed the set value, it will continue to work normally; if the motor current exceeds the set value again, the main control module controls the motor to suspend operation;

[0040] When the motor temperature acquisition module detects that the motor temperature exceeds the set value, it sends a signal to the main control module, which controls the motor to stop working. The motor can only be started again when the motor temperature is lower than the set value.

[0041] When controlling the jack 1 to descend, by pressing the descend button in the safety button area, a signal is sent to the main control module, and the main control module controls the power supply to the electromagnet 1 3. After the electromagnet 1 3 is energized, it drives the transmission member 4 used to push the oil drain valve to open the oil drain valve to return oil, so that the jack 1 is lowered. The electromagnet 1 3 adopts a push-pull electromagnet or other push electromagnet; then the main control module controls the power supply to the electromagnet 2 5. After the electromagnet 2 5 is energized, it is magnetically connected to a metal part, so that the transmission member 4 keeps pushing the oil drain valve to open position, and then the main control module controls the power supply to the electromagnet 1 3.

[0042] During the descent process, the temperature and current of electromagnet 1 3 and electromagnet 2 5 are detected in real time. When the temperature and current of electromagnet 1 3 and electromagnet 2 5 are within the set range, they continue to work normally. When the temperature and current exceed the set range, the main control module controls the display module to light up a red light and simultaneously controls to cut off the power to electromagnet 1 3 and electromagnet 2 5; wait for the temperature to drop below the set value before restarting; after the interruption set time, electromagnet 1 3 and electromagnet 2 5 are powered on again. If the current is lower than the set value, it works normally. If it is still higher than the set value, it is powered off again and stops working;

[0043] After pressing the down button or up button in the safety button area, the main control module controls the up button in the positioning button area to unlock; after unlocking, the jack 1 can be driven to lift by pressing the up button in the positioning button area;

[0044] After the up button in the positioning button area is unlocked, when the up button in the positioning button area is pressed, if the motor current is lower than the current parameter set during positioning, the jack 1 is driven normally to lift. If the motor current exceeds the current parameter set during positioning, the main control module controls the up button and down button in the positioning button area to be locked again.

[0045] When the jack 1 is not in contact with the object being lifted and the jack 1 is controlled to descend, the descending button in the positioning button area is directly pressed to send a signal to the main control module. The main control module controls the electromagnet 1 3 to be energized, thereby opening the oil release valve to return oil and lowering the jack 1.

[0046] When the up button and down button in the positioning button area of ​​the lifted object are in the locked state, to control the jack 1 to descend, first press the down button or up button in the safety button area to send a command to the main control module. After receiving the command, the main control module controls the electromagnet 1 or the motor to work, and unlocks the up button in the positioning button area. After unlocking, continue to press the up button in the positioning button area for a set time. If the motor current exceeds the set current parameter for positioning within the set time, the main control module controls the up button in the positioning button area to lock again. When the motor current does not exceed the set current parameter for positioning within the set time, the down button in the positioning button area is unlocked. After unlocking, press the down button in the positioning button area to send a signal to the main control module. The main control module controls the electromagnet 1 to be energized, thereby opening the oil release valve to return oil, causing the jack to descend.

[0047] During the entire use of the jack 1, the battery pack of the jack 1 is monitored in real time. When the voltage of the battery pack is lower than the set value, the main control module controls the yellow light in the display module to flash, informing the user that the battery voltage is too low. At this time, the voltage of the battery pack cannot start the motor, and can only start the electromagnet 1 3 and the electromagnet 2 5 to drive the jack 1 to descend;

[0048] Through the setting and control of electromagnet 1 3 and electromagnet 2 5, electromagnet 1 3 is used to drive the transmission part 4 to push the oil drain valve to open, and electromagnet 2 5 is used to maintain the position of the transmission part 4, so as to keep the oil drain valve in an open state; after the electromagnet 1 3 is controlled to drive the oil drain valve to open, the electromagnet 2 5 is controlled to move to maintain the position of the electromagnet 1 3 in place, and then the electromagnet 1 3 is controlled to be powered off, and only the electromagnet 2 5 is relied on to maintain the electromagnet 1 3 and the transmission part 4 in place; compared with electromagnet 1 3, the energy consumption required for electromagnet 2 5 when working is lower than that of electromagnet 1 3. It is low and generates less heat, so it can work effectively for a long time. Therefore, through the setting and control of electromagnet 2 5, while ensuring the realization of the oil drain valve function, the overall working energy consumption of the electromagnet is reduced, and at the same time, it is avoided that electromagnet 1 3 is in a high-power state for a long time, which causes the temperature of electromagnet 1 3 to reach the set high temperature value too quickly, thereby avoiding the jack 1 from stopping working due to the temperature of electromagnet 3 exceeding the set temperature value limit when the jack 1 is not completely lowered, causing the jack 1 to stop lowering. It is necessary to wait until the temperature of electromagnet 3 drops before working again, affecting work efficiency.

[0049] In one embodiment, in order to better control the temperature of electromagnet 2 5, when the single continuous working time of electromagnet 2 5 exceeds the set value, the main control module actively cuts off the output at that time, and the jack stops descending. When controlling the descent again, the descending button in the positioning button area or the safety button area is pressed again to send a signal to the main control module. The main control module controls the electromagnet 1 3 to be energized. After the electromagnet 1 3 is energized, it drives the transmission part 4 used to push the oil drain valve to open the oil drain valve to return oil, so that the jack 1 is lowered; then the main control module controls the electromagnet 2 5 to be energized. After the electromagnet 2 5 is energized, it is magnetically connected to a metal part, so that the transmission part 4 keeps pushing the oil drain valve to open position, and then the main control module controls the electromagnet 1 3 to be de-energized to control the jack to continue to descend.

[0050] In one embodiment, the up button and down button of the positioning button area are set at the handle of the jack 1 near the main body of the jack 1 or at any position on the main body of the jack 1, or are set on a control terminal connected to the main control module of the jack 1 through wired or wireless connection; the up button and down button of the safety button area are set on the handle of the jack 1 and on the end away from the jack 1;

[0051] The control terminal and the main control module are connected by wired or wireless connection; when wireless connection is adopted, the control terminal and the main control module are connected through a communication module, and the communication module is selected from any one of a Bluetooth communication module, an RF wireless control module or a network communication module;

[0052] In one embodiment, it also includes a display module controlled by the main control module for displaying different conditions of the jack 1 and the battery pack condition. The display module is used to display green, red and yellow lights. The yellow light is used to display that the battery pack voltage is lower than the set value, the red light is used to display that the temperature and current parameters of the electromagnet 1 3, the electromagnet 2 5 and the motor exceed the set value, and the green light is used to display that the power is on and working normally; the machine can work normally when the green light is on, and stop working when the red light is on. When the yellow light flashes, the motor cannot be started, and only the jack 1 can be started to descend.

[0053] In one embodiment, the main control module controls the electromagnet 3 and the oil drain valve to lower the jack 1, and the main control module controls the solenoid valve to switch the oil return line to lower the jack 1, or controls the main control module to control the rotation direction of the motor 2 and the gear pump to switch the flow direction of the hydraulic oil to lower the jack 1.

[0054] When a solenoid valve is used, the main control module controls the opening and closing of the solenoid valve to realize the opening and closing of the oil return line, thereby realizing the lowering or stopping of the jack 1;

[0055] When the motor 2 and the gear pump are used, the main control module controls the change of the rotation direction of the motor 2 and the gear pump to switch between the lifting and lowering of the jack 1, thereby realizing the lifting or lowering of the jack 1.

[0056] The protection scope of the present invention is not limited to the above embodiment and its variations. Conventional modifications and replacements made by those skilled in the art based on the contents of this embodiment fall within the protection scope of the present invention.

Claims

1. A control method for an electric hydraulic jack with a safety protection function, characterized by: When controlling the positioning of the jack and the object to be lifted, press the rising button in the positioning button area to send a signal to the main control module. The main control module controls the motor to start, and the motor drives the electric pump to start, pumping hydraulic oil into the jack to lift it. During the positioning and lifting process, the motor current acquisition module collects and monitors the motor current. The motor current will increase after the jack contacts the object being lifted. When the motor current acquisition module collects that the motor current exceeds the preset current parameters for positioning, it will feed back to the main control module. The main control module will no longer receive the command signals of the up button and down button in the positioning button area, or will no longer output control commands after receiving the command signals of the up button and down button in the positioning button area. At this time, the up button and down button in the positioning button area are temporarily invalid and in a locked state. At this time, if it is necessary to continue to control the lifting of the jack, the operator must press the up button in the safety button area to send a signal to the main control module. The main control module controls the motor to start, and the motor drives the electric pump to start, and then injects hydraulic oil into the jack to make it continue to lift.

2. The control method of an electric hydraulic jack with a safety protection function according to claim 1, characterized in that: Also included is a control method for controlling the jack to descend by using a descending button in the positioning button area; It includes that when the up button and down button in the positioning button area are not in the locked state, directly pressing the down button in the positioning button area sends a signal to the main control module, and the main control module controls the electromagnet to be energized, thereby opening the oil release valve to return oil and lowering the jack; When the up button and down button in the positioning button area of ​​the lifted object are in the locked state, first press the down button or up button in the safety button area to send an instruction to the main control module. After receiving the instruction, the main control module controls the electromagnet 1 or the motor to work, thereby unlocking the up button in the positioning button area; then continue to press the up button in the positioning button area for a set time. If the motor current exceeds the set current parameter during positioning, the main control module controls the up button in the positioning button area to lock it again. When the motor current does not exceed the set current parameter during positioning within the set time, the down button in the positioning button area is unlocked. After unlocking, press the down button in the positioning button area to send a signal to the main control module. The main control module controls the electromagnet 1 to be energized, thereby opening the oil release valve to return oil, and lowering the jack.

3. The control method of the electric hydraulic jack with safety protection function according to claim 1, characterized in that: The jack is further lifted by the up button in the safety button area. The motor current acquisition module collects and monitors the motor current. When the motor current exceeds the set value, the main control module controls the motor to stop working. After the motor stops working for a set time, the up button in the safety button area is pressed again to control the jack to rise. If the jack rises normally and the motor current does not exceed the set value, normal operation is performed. If the motor current exceeds the set value again, the main control module continues to control the motor to stop working. When controlling the jack to descend, by pressing the descend button in the safety button area, a signal is sent to the main control module, and the main control module controls the electromagnet to be energized, thereby opening the oil release valve to return oil and lowering the jack.

4. A control method for an electric hydraulic jack with a safety protection function according to claim 1, 2 or 3, characterized in that: It also includes collecting and monitoring the motor temperature during the operation of the motor through the temperature acquisition module. When the motor temperature acquisition module detects that the motor temperature exceeds the set value, it sends a signal to the main control module. The main control module controls the motor to stop working. The motor can only be controlled to start again after the motor temperature is lower than the set value.

5. The control method of the electric hydraulic jack with safety protection function according to claim 2, characterized in that: The up button and down button in the positioning button area are set at any position of the jack or on a control terminal that establishes a communication connection with the jack main control module through wired or wireless communication; the up button and down button in the safety button area are set on the handle of the jack and at one end far away from the jack and the object being lifted.

6. A control method for an electric hydraulic jack with a safety protection function according to claim 2 or 3, characterized in that: When the oil drain valve is opened to lower the jack by controlling the action of electromagnet 1, the main control module controls the power supply to electromagnet 1. After electromagnet 1 is energized, it drives the transmission component used to push the oil drain valve to open the oil drain valve to return oil, so that the jack is lowered. Then the main control module controls the power supply to electromagnet 2. After electromagnet 2 is energized, it is magnetically connected to a metal component, so that the transmission component keeps pushing the oil drain valve to open position. Then the main control module controls the power supply to electromagnet 1.

7. The control method of the electric hydraulic jack with safety protection function according to claim 6, characterized in that: During the descent process, the temperature and current of electromagnet 1 and electromagnet 2 are detected in real time. When the temperature and current of electromagnet 1 and electromagnet 2 are within the set range, they continue to work normally. When the temperature and current exceed the set range, the main control module controls to cut off the power to electromagnet 1 and electromagnet 2.

8. The control method of the electric hydraulic jack with safety protection function according to claim 7, characterized in that: It also includes that when the single continuous working time of the electromagnet 2 exceeds the set value, the main control module actively cuts off the output at that time and the jack stops descending.

9. The control method of an electric hydraulic jack with a safety protection function according to claim 1, characterized in that: It also includes a display module controlled by the main control module for displaying the status of the jack and the battery pack.

10. A control method for an electric hydraulic jack with a safety protection function according to claim 2 or 3, characterized in that: The method of lowering the jack by controlling the electromagnet and the oil drain valve by the main control module is replaced by controlling the solenoid valve by the main control module to switch the oil circuit back to lower the jack, or by controlling the rotation direction of the motor and gear pump by the main control module to switch the flow direction of the hydraulic oil to lower the jack.

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