Safety protection system and protection method for station driver type stacker truck

Abstract

The application discloses a safety protection system and method for a station-driving type stacker, and belongs to the technical field of warehouse vehicle safety protection. The system comprises a controller, an interlocking switch, a lifting buffer switch, a descending buffer switch, an OPS switch, a transportation safety switch, a high-position speed limiting switch, an arm protection switch, a station plate sensing switch and a handle. The controller is used for judging the lifting height H of a portal frame, and the working states of the driving motor and the pump motor are controlled according to the signal states of the handle, the station plate sensing switch, the OPS switch, the arm protection switch, the transportation safety switch, the high-position speed limiting switch, the lifting buffer switch and the descending buffer switch. The application can realize the associated control of the driving speed of the station-driving type stacker and the lifting and stacking height.

Description

Technical Field

[0001] This invention relates to the field of warehouse vehicle safety protection technology, and more specifically, to a safety protection system and method for stand-on stacker trucks. Background Technology

[0002] A stand-on stacker truck is a type of vehicle used in warehousing environments. It is equipped with a foldable standing platform, retractable arm protection devices, and a gantry safety control device to ensure the safety of the vehicle's driving and stacking.

[0003] Currently, stand-on stacker trucks generally separate vehicle driving safety and stacking safety control strategies, with driving speed and stacking height being unrelated. Market feedback indicates two scenarios: First, during stacking, a sensor switch reduces the lifting speed of the high-level stacking gantry within the sensing range to ensure high-level stacking safety. However, if the vehicle loses power while stacking is in a high-level position and power is restored, the controller cannot determine the stacking position, thus failing to control the stacking lifting speed, posing a safety hazard in this state. Second, during vehicle operation, the driving speed and stacking height are unrelated, allowing the vehicle to travel at high speeds when the gantry is in a high-level stacking position, also posing a safety hazard. In both scenarios, a power outage during high-level stacking, followed by power restoration, prevents the vehicle from determining the stacking height, resulting in uncontrolled lifting speeds and the vehicle being able to operate at high speeds while stacking, posing a significant safety risk and potentially leading to accidents. In another scenario, during normal vehicle operation, the stacking height cannot be determined at the corresponding driving speed, posing a safety hazard when the vehicle is stacked at a high position and traveling at high speed. Summary of the Invention

[0004] One objective of this invention is to provide a safety protection system and method for a stand-on stacker truck, which can effectively improve the situation where, after a power outage and subsequent power restoration, the vehicle cannot determine the stacking height and the lifting speed is uncontrolled. This optimizes the correlation between the vehicle's stacking height and driving speed, reducing safety accidents and economic losses to customers caused by the above reasons during vehicle use.

[0005] According to a first aspect of the present invention, a safety protection system for a stand-on stacker truck is provided, comprising a controller, an interlock switch, a lifting buffer switch, a lowering buffer switch, an OPS switch, a transport safety switch, a high-position speed limit switch, a guard arm protection switch, a platform sensing switch, and a handle; one end of the interlock switch, one end of the lifting buffer switch, one end of the lowering buffer switch, the OPS switch, the transport safety switch, the high-position speed limit switch, the guard arm protection switch, and one end of the platform sensing switch are respectively connected to the controller; the controller is connected to the power supply terminal of the handle via a bus, the controller power terminal UVW is connected to the drive motor power terminal UVW, and a corresponding port of the controller is also connected to a pump motor; the controller determines the lifting height H of the gantry, and controls the operation of the drive motor and the pump motor according to the signal states of the handle, the platform sensing switch, the OPS switch, the guard arm protection switch, the transport safety switch, the high-position speed limit switch, the lifting buffer switch, and the lowering buffer switch.

[0006] Optionally, the safety protection system for a stand-on stacker truck further includes a battery, a start switch, and a composite switch. The positive terminal of the battery is connected to the power input terminal B+ of the start switch, and the negative terminal of the battery is connected to the negative terminal of the controller and the negative terminal of the handle. The output terminal of the start switch is connected to one normally open switch terminal of the composite switch, the other normally open switch terminal is connected to one coil terminal of the composite switch, the other coil terminal is connected to one end of the first fuse F1, and the contact a terminal of the composite switch is connected to the positive terminal of the battery. In the composite switch, contact b is connected to one end of the second fuse F2; the other end of the first fuse F1 is connected to the controllable power supply terminal of the controller, one end of the interlock switch, one end of the lifting buffer switch, one end of the lowering buffer switch, one end of the OPS switch, one end of the transport safety switch, one end of the high-position speed limit switch, one end of the guard arm protection switch, one end of the station plate sensing switch, and the power supply terminal of the handle; the other end of the second fuse F2 is connected to the power supply terminal of the controller, the positive terminal of the pump motor, and the positive terminal of the lowering solenoid valve.

[0007] Optionally, the drive motor includes an electromagnetic brake, a temperature sensor, and a speed encoder. The control port of the electromagnetic brake is connected to the controller, the signal port of the temperature sensor is connected to the controller, and the signal port of the speed encoder is connected to the controller.

[0008] Optionally, the handle includes a lifting switch, a lowering switch, and an accelerator; the lifting switch is used to trigger a lifting signal, which is transmitted to the controller via a bus, and the controller controls the pump motor to operate, so that the gantry performs a lifting action; the lowering switch is used to trigger a lowering signal, which is transmitted to the controller via a bus, and the controller controls the lowering solenoid valve to operate, so that the gantry performs a lowering action; the accelerator is used to trigger a forward acceleration signal or a reverse acceleration signal, which is transmitted to the controller via a bus, and the controller controls the drive motor to control the corresponding forward and reverse speeds.

[0009] Optionally, the interlock switch, the lifting buffer switch, the lowering buffer switch, the OPS switch, the guard arm protection switch, and the station plate sensing switch are normally open proximity switches, while the transport safety switch and the high-position speed limit switch are steady-state switches.

[0010] Optionally, the controller is a two-in-one AC drive plus DC pump control controller.

[0011] Optionally, the pump motor is a DC motor, and the descending solenoid valve is a proportional solenoid valve.

[0012] Optionally, the interlock switch is installed below the handle shaft to sense the handle's working area; the lifting buffer switch is installed at the gantry height H1 to sense the gantry's lifting height; the lowering buffer switch is installed at the gantry height H0 to sense the gantry's lifting height; the transport safety switch is installed at the gantry height Ha to sense the gantry's lifting height, where Ha > H0; the high-position speed limit switch is installed at the gantry height Hb to sense the gantry's lifting height, where Hb < H1; the OPS switch is installed below the pedal to sense whether the operator is standing on the pedal; the arm guard protection switch is installed below the arm guard shaft to sense the arm guard's retracted / lowered state; and the platform sensing switch is installed below the pedal shaft to sense the platform's retracted / lowered state.

[0013] According to a second aspect of the present invention, a safety protection method for a stand-on stacker truck is provided, comprising the following steps:

[0014] Step 1: Close the composite switch and the start switch in sequence. The battery supplies power to each component. After the controller and handle are powered on, they communicate and connect, putting the vehicle into the starting state.

[0015] Step 2: Press down the handle to close the interlock switch, rotate the accelerator of the handle to trigger the forward or backward acceleration signal, and operate the hoisting switch or descent switch to control the hoisting or descent of the gantry respectively.

[0016] Step 3: When the pedal is open and no one is standing, the controller 4 receives a signal from the station board sensing switch 12 indicating that it is in the closed state, and the signal from the OPS switch 8 indicating that it is in the open state. The vehicle does not perform any driving, lifting, or lowering actions.

[0017] Step 4: When the pedal is open and someone is standing, the guard arm is opened. The controller receives the station board sensing switch signal, OPS switch signal, and guard arm protection switch signal, all of which are in the closed state. Step 2 is executed, and the vehicle moves and lifts / lowers.

[0018] Step 5: When the pedal is open and someone is standing, the guard arm is retracted. The controller receives the station board sensing switch signal and the OPS switch signal as closed, and the guard arm protection switch signal as open. Then, Step 2 is executed, and the vehicle moves and lifts / lowers.

[0019] Step 6: With the pedal retracted and no one standing, the guard arm receives the station plate sensing switch signal and OPS switch signal, which are in the off state, and the guard arm protection switch signal is in the closed state. Then, execute step 2. The vehicle does not perform any driving, lifting, or lowering actions.

[0020] Step 7: With the pedal retracted and no one standing, the guard arm is retracted. The controller receives signals from the station board sensing switch, OPS switch 8, and guard arm protection switch, all of which are in the off state. Step 2 is then executed, and the vehicle begins to move and perform lifting and lowering actions.

[0021] The safety protection system and method for stand-on stacker trucks disclosed herein have the following technical effects:

[0022] This invention uses a controller to determine the lifting height of the gantry, the status of the handle signal, the status of the platform sensing switch signal, the status of the OPS switch signal, the status of the guard arm protection switch signal, the status of the transport safety switch signal, the status of the high-position speed limit switch signal, the status of the lifting buffer switch signal, and the status of the lowering buffer switch signal. Based on this, it controls the operation of the drive motor and the pump motor, realizing the correlation control of vehicle travel speed and lifting stacking height. This reduces safety hazards and economic losses to customers caused by operation, and also provides safety protection for the operator.

[0023] Other features and advantages of the invention will become clear from the following detailed description of exemplary embodiments of the invention with reference to the accompanying drawings. Attached Figure Description

[0024] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the invention and, together with their description, serve to explain the principles of the invention.

[0025] Figure 1 This is a circuit block diagram of a safety protection system for a stand-on stacker truck provided in an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of the entire vehicle for the safety protection system and protection method for a stand-on stacker truck provided in an embodiment of the present invention.

[0027] The diagram is marked as follows:

[0028] 1. Battery; 2. Start switch; 3. Compound switch; 31. Normally open switch; 32. Coil; 4. Controller; 5. Interlock switch; 6. Lifting buffer switch; 7. Lowering buffer switch; 8. OPS switch; 9. Transport safety switch; 10. High-position speed limit switch; 11. Arm protection switch; 12. Station platform sensing switch; 13. Handle; 131. Lifting switch; 132. Lowering switch; 133. Accelerator; 14. Pump motor; 15. Lowering solenoid valve; 16. Drive motor; 161. Electromagnetic brake; 162. Temperature sensor; 163. Speed ​​encoder; 18. Gantry; 19. Pedal; 20. Arm protection. Detailed Implementation

[0029] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0030] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0031] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0032] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0033] In existing technologies, when the vehicle loses power while stacked at a high position, the vehicle cannot determine the stacking height after power is restored, resulting in uncontrolled lifting speed and a safety hazard of high-speed operation while the vehicle is stacked at a high position, which can easily lead to accidents. Furthermore, during normal vehicle operation, the stacking height cannot be determined at the corresponding speed, again posing a safety hazard when the vehicle is stacked at a high position and traveling at high speed. This application uses a controller combined with interlock switches, lifting buffer switches, lowering buffer switches, OPS switches, transport safety switches, high-position speed limit switches, arm protection switches, platform sensing switches, and the signal status of the handle to control the operation of the drive motor and pump motor. It performs correlated control of the vehicle's travel direction, travel speed, gantry lifting speed, and gantry lowering speed, achieving correlated control of the travel speed and lifting / stacking height of the stand-on stacking vehicle.

[0034] This invention proposes an embodiment of a safety protection system for stand-on stacker trucks, specifically, as follows: Figure 1 and Figure 2 As shown, the system includes a controller 4, an interlock switch 5, a lifting buffer switch 6, a lowering buffer switch 7, an OPS switch 8, a transport safety switch 9, a high-position speed limit switch 10, a guard arm protection switch 11, a platform sensing switch 12, and a handle 13. One end of the interlock switch 5 and one end of each of the following switches are connected to the controller 4: the lifting buffer switch 6, the lowering buffer switch 7, the OPS switch 8, the transport safety switch 9, the high-position speed limit switch 10, the guard arm protection switch 11, and the platform sensing switch 12. The controller 4 is connected to the power supply terminal of the handle 13 via a bus. The controller 4 power terminal UVW is connected to the drive motor 16 power terminal UVW, and the corresponding port of the controller 4 is also connected to the pump motor 14. The controller 4 determines the lifting height H of the gantry 18, and controls the operation of the drive motor 16 and the pump motor 14 based on the signal status of the handle 13, the station plate sensing switch 12, the OPS switch 8, the arm protection switch 11, the transport safety switch 9, the high-position speed limit switch 10, the lifting buffer switch 6, and the lowering buffer switch 7, thereby realizing the correlation control of vehicle travel speed and lifting stacking height.

[0035] Specifically, the other end of interlock switch 5 is connected to port M1 of controller 4; the other end of lifting buffer switch 6 is connected to port M29 of controller 4; the other end of lowering buffer switch 7 is connected to port M6 of controller 4; the other end of OPS switch 8 is connected to port M17 of controller 4; the other end of transport safety switch 9 is connected to port M19 of controller 4; the other end of high-position speed limit switch 10 is connected to port M20 of controller 4; the other end of guard arm protection switch 11 is connected to port M17 of controller 4; and the other end of platform sensing switch 12 is connected to port M16 of controller 4. Controller 4 is connected to the CANL and CAN ports of handle 13 via buses M27 and M28. The H port is connected accordingly; the other end of the second fuse F2 is connected to the power supply terminal B+ of controller 4, the positive terminal P+ of pump motor 14, and the positive terminal of descent solenoid valve 15 respectively; the power terminal UVW of drive motor 16 is connected to the power terminal UVW of controller 4 respectively; the negative terminal of pump motor 14 is connected to the P- port of controller; the negative terminal of descent solenoid valve 15 is connected to the M24 port of controller; the EBP port and EBN port of electromagnetic brake 161 are connected to the M2 and M4 ports of controller 4 respectively; the PTHRM port and NTHRM port of temperature sensor 162 are connected to the M22 and M5 ports of controller 4; the power port of speed encoder 163 is connected to the M25 port of controller 4, the negative port of speed encoder 163 is connected to the M5 port of controller 4, the PHA port of speed encoder 163 is connected to the M14 port of controller 4, and the PHB port of speed encoder 163 is connected to the M13 port of controller 4.

[0036] In this embodiment of the invention, the safety protection system for a stand-on stacker truck further includes a battery 1, a start switch 2, and a composite switch 3. The positive terminal of the battery 1 is connected to the power input terminal B+ of the start switch 2, and the negative terminal of the battery 1 is connected to the negative terminal of the controller 4 and the negative terminal of the handle 13. The output terminal of the start switch 2 is connected to one end of the normally open switch 31 in the composite switch 3. The other end of the normally open switch 31 in the composite switch 3 is connected to one end of the coil 32 in the composite switch 3. The other end of the coil 32 in the composite switch 3 is connected to one end of the first fuse F1. The contact a terminal in the composite switch 3 is connected to the positive terminal of the battery 1. Terminal b is connected to one end of the second fuse F2; the other end of the first fuse F1 is connected to the controllable power supply terminal M10 of the controller 4, the power port of the interlock switch 5, the power port of the lifting buffer switch 6, the power port of the lowering buffer switch 7, the power port of the OPS switch 8, the power port of the transport safety switch 9, the power port of the high-position speed limit switch 10, the power port of the guard arm protection switch 11, the power port of the station plate sensing switch 12, and the power port of the handle 13; the other end of the second fuse F2 is connected to the power supply terminal of the controller 4, the positive terminal of the pump motor 14, and the positive terminal of the lowering solenoid valve 15.

[0037] In this embodiment of the invention, the drive motor 16 includes an electromagnetic brake 161, a temperature sensor 162, and a speed encoder 163. The control port of the electromagnetic brake 161 is connected to the controller 4, and the controller 4 sends an electrical signal to control the activation and release of the electromagnetic brake. The signal port of the temperature sensor 162 is connected to the controller 4, and the temperature sensor sends real-time temperature data to the controller. The controller adjusts the operating state of the motor according to the received temperature data to prevent the motor from overheating. The signal port of the speed encoder 163 is connected to the controller 4, and the speed encoder sends real-time speed data of the motor to the controller. The controller adjusts the control strategy of the motor according to the speed data to achieve precise speed control or speed feedback control. By integrating the electromagnetic brake 161, the temperature sensor 162, and the speed encoder 163, and tightly connecting them with the controller 4, the drive motor 16 forms a highly efficient and reliable motor control system.

[0038] In this embodiment of the invention, the handle 13 includes a lifting switch 131, a lowering switch 132, and an accelerator 133. The lifting switch 131 is used to trigger a lifting signal, which is transmitted to the controller 4 via a bus. The controller 4 controls the pump motor 14 to operate, so that the gantry 18 performs a lifting action. The lowering switch 132 is used to trigger a lowering signal, which is transmitted to the controller 4 via a bus. The controller 4 controls the lowering solenoid valve 15 to operate, so that the gantry 18 performs a lowering action. The accelerator 133 is used to trigger a forward acceleration signal or a reverse acceleration signal, which is transmitted to the controller 4 via a bus. The controller 4 controls the drive motor 16 to operate at the corresponding forward and reverse speeds. The accelerator 133 is a bidirectional controller that can trigger both forward acceleration and backward acceleration signals. These signals are transmitted to the controller 4 via a bus. The controller 4 adjusts the speed and direction of the drive motor 16 based on the received signals, thereby controlling the forward or backward speed of the vehicle. When the operator pushes the accelerator 133 forward, it sends a forward acceleration signal to the controller 4; when the operator pulls the accelerator 133 backward, it sends a backward acceleration signal.

[0039] In this embodiment of the invention, the interlock switch 5, lifting buffer switch 6, lowering buffer switch 7, OPS switch 8, arm guard protection switch 11, and platform sensing switch 12 are normally open proximity switches. Specifically, when no object (such as the forklift's arm guard or platform) is approaching, the interlock switch 5, lifting buffer switch 6, lowering buffer switch 7, OPS switch 8, arm guard protection switch 11, and platform sensing switch 12 are in the open state. When the relevant components are in the correct position or approach to a certain distance, the interlock switch 5, lifting buffer switch 6, lowering buffer switch 7, OPS switch 8, arm guard protection switch 11, and platform sensing switch 12 close, sending a signal to allow or execute the corresponding operation. For example, the arm guard protection switch is used to detect whether the arm guard is fully extended and locked; lifting or lowering operations are only allowed when the arm guard is correctly positioned.

[0040] Transportation safety switch 9 and high-position speed limit switch 10 are steady-state switches. Specifically, transportation safety switches are installed to ensure safety during transportation, and they may include various types such as emergency stop buttons, safety door switches, and safety pull rope switches. The high-position speed limit switch is an important safety device used in transportation equipment to control the operating speed.

[0041] In this embodiment of the invention, controller 4 is a two-in-one AC drive and DC pump control controller. Specifically, controller 4 integrates two main functions: AC drive control and DC pump control. Controller 4 controls the speed, torque, and power output of the AC motor by adjusting parameters such as the input voltage, current, or frequency to meet the needs of different operating conditions. Controller 4 controls the flow rate, pressure, and speed of the DC pump by adjusting parameters such as the input voltage, current, or duty cycle to meet specific process requirements. As a "two-in-one AC drive and DC pump control controller," controller 4 not only enables precise control of the AC motor, improving the operating efficiency and stability of the equipment, but also allows for flexible adjustment of the DC pump to meet various complex process requirements.

[0042] In this embodiment of the invention, the pump motor 14 is a DC motor, and the lowering solenoid valve 15 is a proportional solenoid valve. The DC motor generates significant torque during startup, making it excellent for applications requiring rapid and heavy-load starts. Due to its good speed regulation and starting characteristics, the DC motor can meet the precise control requirements of hydraulic systems for changes in flow and pressure. The proportional solenoid valve's opening is continuously adjustable, making it very useful in applications requiring precise control of fluid parameters. Furthermore, proportional solenoid valves are typically driven by electromagnetic force, resulting in fast response speeds and high control accuracy.

[0043] In this embodiment of the invention, the interlock switch 5 is installed below the handle shaft to sense the working area of ​​the handle; the lifting buffer switch 6 is installed at the height H1 of the gantry 18 to sense the lifting height of the gantry; the lowering buffer switch 7 is installed at the height H0 of the gantry 18 to sense the lifting height of the gantry; the transport safety switch 9 is installed at the height Ha of the gantry 18 to sense the lifting height of the gantry, wherein Ha > H0; the high-position speed limit switch 10 is installed at the height Hb of the gantry 18 to sense the lifting height of the gantry, wherein Hb < H1; the OPS switch 8 is installed below the pedal 19 to sense whether the operator is standing on the pedal 19; the arm guard protection switch 11 is installed below the shaft of the arm guard 20 to sense the retracted and lowered state of the arm guard 20; and the platform sensing switch 12 is installed below the shaft of the pedal 19 to sense the retracted and lowered state of the pedal 19.

[0044] The present invention also provides an embodiment of a safety protection method for a stand-on stacker truck, comprising the following steps:

[0045] Step 1: Close the composite switch 3 and the start switch 2 in sequence. The battery 1 supplies power to each component. After the controller 4 and the handle 13 are powered on, they communicate with each other, so that the whole vehicle enters the starting state.

[0046] Step 2: By pressing down the handle 13, the interlock switch 5 is closed by sensing. Rotating the accelerator 133 of the handle 13 triggers the forward or backward acceleration signal. Operating the hoisting switch 131 or the lowering switch 132 controls the hoisting or lowering action of the gantry 18 respectively.

[0047] Step 3: When pedal 19 is open and no one is standing on it, controller 4 receives a signal from station board sensing switch 12 indicating that it is in the closed state, and OPS switch 8 indicates that it is in the open state. The vehicle does not perform any driving, lifting, or lowering actions.

[0048] Step 4: When pedal 19 is opened and someone is standing, the guard arm 20 is opened. The controller 4 receives signals from the station plate sensing switch 12, OPS switch 8, and guard arm protection switch 11, all of which are in a closed state. Step 2 is executed, and the vehicle moves and lifts / lowers.

[0049] It should be noted that in step 4, when the lifting height H of the gantry 18 is less than or equal to H0, the controller 4 receives a signal from the transport safety switch 9 that is in the open state, and the signal from the descent buffer switch 7 that is in the closed state. The maximum driving speed of the vehicle is the set full speed state V0; the maximum lifting speed of the gantry is the set full speed state V1; and the maximum descent speed of the gantry is the set full speed state V2 / 5.

[0050] In step 4, when the lifting height of the gantry 18 is H0 < H < Ha, the controller 4 receives a signal from the transport safety switch 9 that it is in the off state, the lowering buffer switch 7 signal that it is in the off state, the maximum driving speed of the whole vehicle is the set full speed state V0; the maximum lifting speed of the gantry 18 is the set full speed state V1, and the maximum lowering speed of the gantry 18 is the set full speed state V2.

[0051] In step 4, when the lifting height Ha of the gantry 18 is ≤ H < Hb, the controller 4 receives a signal from the transport safety switch 9 that is closed, the lifting buffer switch 6 that is open, the lowering buffer switch 7 that is open, the high-position speed limit switch 10 that is open, the maximum driving speed of the vehicle reaches the set V0 / 2, the maximum lifting speed of the gantry 18 is the set full speed state V1, and the maximum lowering speed of the gantry 18 is the set full speed state V2.

[0052] In step 4, when the height Hb of the gantry 18 is less than or equal to H, the controller 4 receives a signal from the transport safety switch 9 that is closed, the lifting buffer switch 6 that is closed, the lowering buffer switch 7 that is open, and the high-position speed limit switch 10 that is closed. The vehicle cannot perform driving or lifting actions.

[0053] In step 4, when the height H of the gantry 18 is in any of the above states, the vehicle is powered off and then restarted. After restarting, the vehicle remains in the state before the power outage.

[0054] Step 5: When pedal 19 is opened and someone is standing, the guard arm 20 is retracted. The controller 4 receives signals from the station board sensing switch 12 and the OPS switch 8, which are in the closed state. The guard arm protection switch 11 is in the open state. Step 2 is executed, and the vehicle moves and lifts / lowers.

[0055] It should be noted that in step 5, when the lifting height H of the gantry 18 is less than or equal to H0, the controller 4 receives a signal from the transport safety switch 9 indicating that it is in the open state, and a signal from the descent buffer switch 7 indicating that it is in the closed state. The maximum driving speed of the vehicle is the set full speed state V0 / 2; the maximum lifting speed of the gantry is the set full speed state V1; and the maximum lowering speed of the gantry is the set full speed state V2 / 5.

[0056] In step 5, when the lifting height of the gantry 18 is H0 < H < Ha, the controller 4 receives the signal from the transport safety switch 9 (which is in the off state) and the signal from the descent buffer switch 7 (which is in the off state). The maximum travel speed of the vehicle is the set full speed state V0 / 2; the maximum lifting speed of the gantry 18 is the set full speed state V1; and the maximum descent speed of the gantry 18 is the set full speed state V2.

[0057] In step 5, when the lifting height Ha of the gantry 18 is ≤ H < Hb, the controller 4 receives a signal from the transport safety switch 9 that is closed, the lifting buffer switch 6 that is open, the lowering buffer switch 7 that is open, and the high-position speed limit switch 10 that is open. The maximum driving speed of the vehicle reaches the set V0 / 2. The maximum lifting speed of the gantry 18 is the set full speed state V1, and the maximum lowering speed of the gantry 18 is the set full speed state V2.

[0058] In step 5, when the lifting height Hb of the gantry 18 is ≤ H < H1, the controller 4 receives a signal from the transport safety switch 9 that is closed, the lifting buffer switch 6 that is open, the lowering buffer switch 7 that is open, and the high-position speed limit switch 10 that is closed. The maximum travel speed of the vehicle reaches the set V0 / 5; the maximum lifting speed of the gantry is the set full speed state V1; and the maximum lowering speed of the gantry is the set full speed state V2.

[0059] In step 5, when the height H1 of the outer gantry 18 of the vehicle is less than or equal to H, the controller 4 receives a signal from the transport safety switch 9 that is closed, the lifting buffer switch 6 that is closed, the lowering buffer switch 7 that is open, and the high-position speed limit switch 10 that is closed. The maximum driving speed of the vehicle reaches the set V0 / 5; the maximum lifting speed of the gantry is the set full speed V1 / 5; ​​and the maximum lowering speed of the gantry is the set full speed V2.

[0060] In step 5, when the height H of the gantry 18 is in any of the above states, the vehicle is powered off and then restarted. After restarting, the vehicle remains in the state before the power outage.

[0061] Step 6: With pedal 19 retracted and no one standing, open guard arm 20. The controller 4 receives signals from station board sensing switch 12 and OPS switch 8, which are in the off state, and guard arm protection switch 11, which is in the closed state. Execute step 2. The vehicle does not perform any driving, lifting, or lowering actions.

[0062] It should be noted that in step 6, when the pedal 19 is retracted and the operator is not standing on the pedal 19, the guard arm 20 is opened, the controller 4 receives a signal from the station plate sensing switch 12 that it is in the off state, the OPS switch 8 signal that it is in the off state, and the guard arm protection switch 11 signal that it is in the closed state, and step 2 is executed, the whole vehicle does not perform any driving, lifting or lowering actions.

[0063] Step 7: When pedal 19 is retracted and no one is standing, the guard arm 20 is retracted. The controller 4 receives signals from the station board sensing switch 12, the OPS switch 8, and the guard arm protection switch 11, all of which are in the off state. Step 2 is executed, and the vehicle moves and lifts / lowers.

[0064] It should be noted that in step 7, the pedal 19 is retracted, the operator does not stand on the pedal 19, the guard arm 20 is retracted, the controller 4 receives the signal from the station plate sensing switch 12 that it is in the off state, the signal from the OPS switch 8 that it is in the off state, the signal from the guard arm protection switch 11 that it is in the off state, and then step 2 is executed, and the whole vehicle moves and lifts and lowers.

[0065] Specifically, in step 7, when the lifting height H of the gantry 18 is less than or equal to H0, the controller 4 receives a signal from the transport safety switch 9 that is in the open state, and a signal from the descent buffer switch 7 that is in the closed state. The maximum driving speed of the vehicle is the set full speed state V0 / 2; the maximum lifting speed of the gantry 18 is the set full speed state V1; and the maximum descent speed of the gantry 18 is the set full speed state V2 / 5.

[0066] In step 7, when the lifting height of the gantry 18 is H0 < H < Ha, the controller 4 receives the signal from the transport safety switch 9 (which is in the off state) and the signal from the descent buffer switch 7 (which is in the off state). The maximum travel speed of the vehicle is the set full speed state V0 / 2; the maximum lifting speed of the gantry 18 is the set full speed state V1; and the maximum descent speed of the gantry 18 is the set full speed state V2.

[0067] In step 7, when the lifting height Ha of the gantry 18 is ≤ H < Hb, the controller 4 receives a signal from the transport safety switch 9 that is closed, the lifting buffer switch 6 that is open, the lowering buffer switch 7 that is open, and the high-position speed limit switch 10 that is open. The maximum driving speed of the vehicle reaches the set V0 / 2; the maximum lifting speed of the gantry 18 is the set full speed state V1; and the maximum lowering speed of the gantry 18 is the set full speed state V2.

[0068] In step 7, when the lifting height Hb of the gantry 18 is less than or equal to H1, the controller 4 receives a signal from the transport safety switch 9 that is closed, the lifting buffer switch 6 that is open, the lowering buffer switch 7 that is open, and the high-position speed limit switch 10 that is closed. The maximum driving speed of the vehicle reaches the set V0 / 5; the maximum lifting speed of the gantry 18 is the set full speed V1; and the maximum lowering speed of the gantry 18 is the set full speed V2.

[0069] In step 7, when the lifting height H1 of the gantry 18 is less than or equal to H, the controller 4 receives a signal from the transport safety switch 9 that is closed, the lifting buffer switch 6 that is closed, the lowering buffer switch 7 that is open, and the high-position speed limit switch 10 that is closed. The maximum driving speed of the vehicle reaches the set V0 / 5; the maximum lifting speed of the gantry 18 is the set full speed V1 / 5; ​​and the maximum lowering speed of the gantry 18 is the set full speed V2.

[0070] In step 7, when the height H of the gantry 18 is in any of the above states, the vehicle is powered off and then restarted. After restarting, the vehicle remains in the state before the power outage.

[0071] The present invention also provides another embodiment of a safety protection method for a stand-on stacker truck, comprising the following sequential steps:

[0072] (1) Close the composite switch 3 and the start switch 2. The battery 1 supplies power to the controller 4, interlock switch 5, lifting buffer switch 6, lowering buffer switch 7, OPS switch 8, transport safety switch 9, high-position speed limit switch 10, guard arm protection switch 11, station plate sensing switch 12, handle 13, pump motor 14, and lowering solenoid valve 15. After the controller 4 and handle 13 are powered on, communication is established, and the whole vehicle is in the start state.

[0073] (2) Open pedal 19, without the operator standing on pedal 19, operate handle 13, normally trigger any signal, the whole vehicle will not perform driving and lifting actions;

[0074] (3) Open the pedal 19, the operator stands on the pedal 19, open the guard arm 20, operate the handle 13, and the controller 4 determines the lifting height H of the mast 18, and the whole vehicle executes different driving speeds and different mast lifting and lowering speeds.

[0075] (4) Open the pedal 19, the operator stands on the pedal 19, retracts the guard arm 20, operates the handle 13, and the controller 4 determines the lifting height H of the mast 18, and the whole vehicle executes different driving speeds and different mast lifting and lowering speeds.

[0076] (5) Retract the pedal 19, the operator does not stand on the pedal 19, open the guard arm 20, operate the handle 13, and normally trigger any signal, the whole vehicle will not perform driving and lifting actions;

[0077] (6) Retract the pedal 19, the operator does not stand on the pedal 19, retract the guard arm 20, operate the handle 13, and the controller 4 determines the lifting height H of the mast 18, and the whole vehicle executes different driving speeds and different mast lifting and lowering speeds.

[0078] It should be noted that steps (2), (3), (4), (5), and (6) are independent states and are all performed on the premise of completing step (1). After the vehicle starts, the controller 4 receives the start signal, judges the signal status of the station board sensing switch 12, the signal status of the OPS switch 8, the signal status of the arm protection switch, the lifting height H information of the gantry 18, and the trigger information of the handle 13, and controls the vehicle to perform driving functions, gantry lifting, and gantry lowering working states based on the above information. Specifically, the steps are as follows:

[0079] Battery 1 serves as the system power source, directly powering the start switch 2. Battery 1 supplies power to controller 4, interlock switch 5, lifting buffer switch 6, lowering buffer switch 7, OPS switch 8, transport safety switch 9, high-position speed limit switch 10, guard arm protection switch 11, platform sensing switch 12, handle 13, pump motor 14, and lowering solenoid valve 15. After controller 4 and handle 13 are energized, communication is established, and the vehicle is in start-up mode.

[0080] After the vehicle starts, the controller 4 judges the status of the station board sensing signal, the status of the OPS switch 8 signal, the status of the guard arm protection switch signal, and the lifting height H information of the gantry 18.

[0081] Open the arm guard 20, the operator stands on the footboard 19, the gantry 18 is raised to a height H≤H0, press down the handle 13, the interlock switch 5 is closed, the accelerator 133 of the handle 13 is turned to trigger the forward acceleration signal (reverse signal), the controller 4 controls the drive motor 16 to travel in the forward (reverse) direction, the maximum travel speed is V0; trigger the lifting switch 131 to trigger the lifting signal, the controller 4 controls the pump motor 14 to work, the gantry 18 performs the lifting action, the maximum lifting speed is V1; trigger the lowering switch 132 to trigger the lowering signal, the controller 4 controls the lowering solenoid valve 15 to work, the gantry 18 performs the lowering action, the maximum lowering speed is V2 / 5;

[0082] Open the arm guard 20, the operator stands on the footboard 19, the gantry 18 is raised to a height H0 < H < Ha, press down the handle 13, the interlock switch 5 is closed, the accelerator 133 of the handle 13 is turned to trigger the forward acceleration signal (reverse signal), the controller 4 controls the drive motor 16 to travel in the forward (reverse) direction, the maximum travel speed is V0; trigger the lifting switch 131 to trigger the lifting signal, the controller 4 controls the pump motor 14 to work, the gantry 18 performs the lifting action, the maximum lifting speed is V1; trigger the lowering switch 132 to trigger the lowering signal, the controller 4 controls the lowering solenoid valve 15 to work, the gantry 18 performs the lowering action, the maximum lowering speed is V2;

[0083] Open the arm guard 20, the operator stands on the footboard 19, the gantry 18 is raised to a height Ha ≤ H < Hb, press down the handle 13, the interlock switch 5 is closed, the accelerator 133 of the handle 13 is turned to trigger the forward acceleration signal (reverse signal), the controller 4 controls the drive motor 16 to travel in the forward (reverse) direction, the maximum travel speed is V0 / 2; trigger the lifting switch 131 to trigger the lifting signal, the controller 4 controls the pump motor 14 to work, the gantry 18 performs the lifting action, the maximum lifting speed is V1; trigger the lowering switch 132 to trigger the lowering signal, the controller 4 controls the lowering solenoid valve 15 to work, the gantry 18 performs the lowering action, the maximum lowering speed is V2;

[0084] Open the guard arm 20, the operator stands on the footboard 19, the mast 18 is raised to a height Hb≤H, press down the handle 13, the interlock switch 5 is closed, turn the accelerator 133 of the handle 13 to trigger the forward acceleration signal (reverse signal), the whole vehicle does not perform the driving action; trigger the lifting switch 131 to trigger the lifting signal, the whole vehicle does not perform the mast lifting action; trigger the lowering switch 132 to trigger the lowering signal, the whole vehicle does not perform the mast lowering action;

[0085] Retract the arm guard 20, set the operator to the standing foot pedal 19, raise the gantry 18 to a height H≤H0, press down the handle 13, the interlock switch 5 is activated and closed, rotate the handle 13, the accelerator 133 triggers a forward acceleration signal (reverse signal), the controller 4 controls the drive motor 16 to move forward (reverse), the maximum travel speed is V0 / 2; trigger the lifting switch 131 to trigger a lifting signal, the controller 4 controls the pump motor 14 to work, the gantry 18 performs a lifting action, the maximum lifting speed is V1; trigger the lowering switch 132 to trigger a lowering signal, the controller 4 controls the lowering solenoid valve 15 to work, the gantry 18 performs a lowering action, the maximum lowering speed is V2 / 5;

[0086] Retract the arm guard 20, set the operator to the standing foot pedal 19, raise the gantry 18 to a height H0 < H < Ha, press down the handle 13, the interlock switch 5 is activated and closed, rotate the handle 13, the accelerator 133 triggers a forward acceleration signal (reverse signal), the controller 4 controls the drive motor 16 to move forward (reverse), the maximum travel speed is V0 / 2; trigger the lifting switch 131 to trigger a lifting signal, the controller 4 controls the pump motor 14 to work, the gantry 18 performs a lifting action, the maximum lifting speed is V1; trigger the lowering switch 132 to trigger a lowering signal, the controller 4 controls the lowering solenoid valve 15 to work, the gantry 18 performs a lowering action, the maximum lowering speed is V2;

[0087] Retract the arm guard 20, set the operator to the standing foot pedal 19, raise the gantry 18 to a height Ha ≤ H < Hb, press down the handle 13, the interlock switch 5 is activated and closed, rotate the handle 13 to trigger the forward acceleration signal 133 (reverse signal), the controller 4 controls the drive motor 16 to move forward (reverse), the maximum travel speed is V0 / 2; trigger the lifting switch 131 to trigger the lifting signal, the controller 4 controls the pump motor 14 to work, the gantry 18 performs the lifting action, the maximum lifting speed is V1; trigger the lowering switch 132 to trigger the lowering signal, the controller 4 controls the lowering solenoid valve 15 to work, the gantry 18 performs the lowering action, the maximum lowering speed is V2;

[0088] Retract the arm guard 20, set the operator to the standing foot pedal 19, raise the gantry 18 to a height Hb ≤ H < H1, press down the handle 13, the interlock switch 5 is activated and closed, rotate the handle 13 to trigger the forward acceleration signal 133 (reverse signal), the controller 4 controls the drive motor 16 to move in the forward (reverse) direction, the maximum travel speed is V0 / 5; trigger the lifting switch 131 to trigger the lifting signal, the controller 4 controls the pump motor 14 to work, the gantry 18 performs the lifting action, the maximum lifting speed is V1; trigger the lowering switch 132 to trigger the lowering signal, the controller 4 controls the lowering solenoid valve 15 to work, the gantry 18 performs the lowering action, the maximum lowering speed is V2;

[0089] Retract the arm guard 20, set the operator to the standing foot pedal 19, raise the gantry 18 to a height H1 ≤ H, press down the handle 13, the interlock switch 5 is activated and closed, rotate the handle 13, the accelerator 133 triggers a forward acceleration signal (reverse signal), the controller 4 controls the drive motor 16 to move forward (reverse), the maximum travel speed is V0 / 5; trigger the lifting switch 131 to trigger a lifting signal, the controller 4 controls the pump motor 14 to work, the gantry 18 performs a lifting action, the maximum lifting speed is V1 / 5; ​​trigger the lowering switch 132 to trigger a lowering signal, the controller 4 controls the lowering solenoid valve 15 to work, the gantry 18 performs a lowering action, the maximum lowering speed is V2;

[0090] Retract the guard arm 20 and the pedal 19. The operator does not stand on the pedal 19. The lifting height of the gantry 18 is H≤H0. Press down the handle 13. The interlock switch 5 is closed. Rotate the accelerator 133 of the handle 13 to trigger the forward acceleration signal (reverse signal). The controller 4 controls the drive motor 16 to travel in the forward (reverse) direction, with a maximum travel speed of V0 / 2. Trigger the lifting switch 131 to trigger the lifting signal. The controller 4 controls the pump motor 14 to work, and the gantry 18 performs a lifting action, with a maximum lifting speed of V1. Trigger the lowering switch 132 to trigger the lowering signal. The controller 4 controls the lowering solenoid valve 15 to work, and the gantry 18 performs a lowering action, with a maximum lowering speed of V2 / 5.

[0091] Retract the guard arm 20 and the pedal 19. The operator does not stand on the pedal 19. The lifting height of the gantry 18 is Ha≤H<Hb. Press down the handle 13. The interlock switch 5 is closed by sensing. Rotate the accelerator 133 of the handle 13 to trigger the forward acceleration signal (reverse signal). The controller 4 controls the drive motor 16 to travel in the forward (reverse) direction, with a maximum travel speed of V0 / 2. Trigger the lifting switch 131 to trigger the lifting signal. The controller 4 controls the pump motor 14 to work, and the gantry 18 performs a lifting action, with a maximum lifting speed of V1. Trigger the lowering switch 132 to trigger the lowering signal. The controller 4 controls the lowering solenoid valve 15 to work, and the gantry 18 performs a lowering action, with a maximum lowering speed of V2.

[0092] Retract the guard arm 20 and the pedal 19. The operator does not stand on the pedal 19. The lifting height of the gantry 18 is Hb≤H

[0093] Retract the guard arm 20 and the pedal 19. The operator does not stand on the pedal 19. The lifting height of the gantry 18 is H1≤H. Press down the handle 13. The interlock switch 5 is closed. Rotate the accelerator 133 of the handle 13 to trigger the forward acceleration signal (reverse signal). The controller 4 controls the drive motor 16 to travel in the forward (reverse) direction, with a maximum travel speed of V0 / 5. Trigger the lifting switch 131 to trigger the lifting signal. The controller 4 controls the pump motor 14 to work, and the gantry 18 performs a lifting action, with a maximum lifting speed of V1 / 5. Trigger the lowering switch 132 to trigger the lowering signal. The controller 4 controls the lowering solenoid valve 15 to work, and the gantry 18 performs a lowering action, with a maximum lowering speed of V2.

[0094] Open the guard arm 20, retract the pedal 19, and the operator does not stand on the pedal 19. The vehicle does not perform any driving, lifting, or lowering actions.

[0095] With the guard arm 20 open and the pedal 19 open, the operator does not stand on the pedal 19, and the vehicle does not perform any driving, lifting, or lowering actions.

[0096] With the guard arm 20 closed and the pedal 19 retracted, the operator does not stand on the pedal 19, and the vehicle does not perform any driving, lifting, or lowering actions.

[0097] In all the above working states, if the vehicle is powered off and restarted, the transport safety switch 9 and the high-position speed limit switch 10 will remain in the state before the power failure. The controller 4 can determine the height H of the gantry 18 through the transport safety switch 9 and the high-position speed limit switch 10, and then re-execute the above actions.

[0098] ​In summary, this invention, through the use of controller 4 in conjunction with interlock switch 5, lifting buffer switch 6, lowering buffer switch 7, OPS switch 8, transport safety switch 9, high-position speed limit switch 10, arm protection switch 11, platform sensing switch 12, and handle 13 signal status, controls the operation of drive motor 16 and pump motor 14. It correlates and controls the vehicle's travel direction, travel speed, gantry lifting speed, and gantry lowering speed, achieving intelligent correlation between travel speed and lifting stacking height. This ensures that vehicle speed meets safety standards at different heights, preventing loss of control or overturning due to excessive speed. This invention, through a highly integrated controller combined with multiple safety switches and sensors, achieves comprehensive monitoring and intelligent control of key operations such as vehicle travel, lifting, and lowering, effectively improving operational safety and reducing accident risks.

[0099] The above description of the structure, features, and effects of the present invention is based on the embodiments shown in the figures. However, the above are only preferred embodiments of the present invention. It should be noted that the technical features involved in the above embodiments and their preferred methods can be reasonably combined and matched by those skilled in the art to form a variety of equivalent solutions without departing from or changing the design concept and technical effects of the present invention. Therefore, the present invention is not limited to the scope of implementation shown in the figures. Any changes made in accordance with the concept of the present invention, or modifications to equivalent embodiments, that do not exceed the spirit covered by the specification and figures, should be within the protection scope of the present invention.

Claims

1. A safety protection system for a stand-on stacker truck, characterized in that, The system includes a controller (4), an interlock switch (5), a lifting buffer switch (6), a lowering buffer switch (7), an OPS switch (8), a transport safety switch (9), a high-position speed limit switch (10), a guard arm protection switch (11), a platform sensing switch (12), and a handle (13). One end of the interlock switch (5), and one end of the lifting buffer switch (6), the lowering buffer switch (7), the OPS switch (8), the transport safety switch (9), the high-position speed limit switch (10), the guard arm protection switch (11), and the platform sensing switch (12) are respectively connected to the controller (4). The controller (4) is connected via... The bus is connected to the power terminal of the handle (13), the power terminal of the controller (4) is connected to the power terminal of the drive motor (16), and the corresponding port of the controller (4) is also connected to the pump motor (14); the controller (4) determines the lifting height of the gantry (18), and controls the operation of the drive motor (16) and the pump motor (14) according to the signal status of the handle (13), the station plate sensing switch (12), the OPS switch (8), the arm protection switch (11), the transport safety switch (9), the high-position speed limit switch (10), the lifting buffer switch (6), and the lowering buffer switch (7); The interlock switch (5) is installed below the handle shaft and is used to sense the working area of ​​the handle; The lifting buffer switch (6) for sensing the lifting height of the gantry is installed at the height H1 of the gantry (18), the lowering buffer switch (7) is installed at the height H0 of the gantry (18), the transport safety switch (9) is installed at the height Ha of the gantry (18), and the high-position speed limit switch (10) is installed at the height Hb of the gantry (18), wherein Ha > H0, Hb < H1, and Ha < Hb; The OPS switch (8) is installed below the pedal (19) and is used to sense whether the operator is standing on the pedal (19); The arm protection switch (11) is installed below the arm (20) shaft and is used to sense the arm (20) retracted and lowered state. The station board sensing switch (12) is installed below the rotating shaft of the pedal (19) and is used to sense the retracted and lowered state of the pedal (19).

2. The safety protection system for a stand-on stacker truck according to claim 1, characterized in that, It also includes a storage battery (1), a start switch (2), and a composite switch (3). The positive terminal of the storage battery (1) is connected to the power input terminal B+ of the start switch (2), and the negative terminal of the storage battery (1) is connected to the negative terminal of the controller (4) and the negative terminal of the handle (13). The output terminal of the start switch (2) is connected to one end of the normally open switch (31) in the composite switch (3), and the other end of the normally open switch (31) in the composite switch (3) is connected to one end of the coil (32) in the composite switch (3). The other end of the coil (32) in the composite switch (3) is connected to one end of the first fuse F1. The contact a terminal in the composite switch (3) is connected to the positive terminal of the storage battery (1). The contact b end of the switch (3) is connected to one end of the second fuse F2; the other end of the first fuse F1 is connected to the controllable power supply terminal of the controller (4), one end of the interlock switch (5), one end of the lifting buffer switch (6), one end of the lowering buffer switch (7), one end of the OPS switch (8), one end of the transport safety switch (9), one end of the high-position speed limit switch (10), one end of the guard arm protection switch (11), one end of the station plate sensing switch (12), and the power supply terminal of the handle (13); the other end of the second fuse F2 is connected to the power supply terminal of the controller (4), the positive terminal of the pump motor (14), and the positive terminal of the lowering solenoid valve (15).

3. The safety protection system for a stand-on stacker truck according to claim 1, characterized in that, The drive motor (16) includes an electromagnetic brake (161), a temperature sensor (162), and a speed encoder (163). The control port of the electromagnetic brake (161) is connected to the controller (4), the signal port of the temperature sensor (162) is connected to the controller (4), and the signal port of the speed encoder (163) is connected to the controller (4).

4. The safety protection system for a stand-on stacker truck according to claim 2, characterized in that, The handle (13) includes a lifting switch (131), a lowering switch (132), and an accelerator (133). The lifting switch (131) is used to trigger a lifting signal and transmit the lifting signal to the controller (4) via a bus. The controller (4) controls the pump motor (14) to work so that the gantry (18) can lift. The lowering switch (132) is used to trigger a lowering signal and transmit the lowering signal to the controller (4) via a bus. The controller (4) controls the lowering solenoid valve (15) to work so that the gantry (18) can lower. The accelerator (133) is used to trigger a forward acceleration signal or a backward acceleration signal and transmit the forward acceleration signal or the backward acceleration signal to the controller (4) via a bus. The controller (4) controls the drive motor (16) to move in the forward direction and backward direction respectively.

5. The safety protection system for a stand-on stacker truck according to claim 1, characterized in that, The interlock switch (5), the lifting buffer switch (6), the lowering buffer switch (7), the OPS switch (8), the guard arm protection switch (11), and the station plate sensing switch (12) are normally open proximity switches, while the transport safety switch (9) and the high-position speed limit switch (10) are steady-state switches.

6. The safety protection system for a stand-on stacker truck according to claim 1, characterized in that, The controller (4) is a two-in-one AC drive plus DC pump control controller.

7. The safety protection system for a stand-on stacker truck according to claim 2, characterized in that, The pump motor (14) is a DC motor, and the descending solenoid valve (15) is a proportional solenoid valve.

8. A safety protection method for a stand-on stacker truck, implemented using the safety protection system for a stand-on stacker truck as described in any one of claims 2, 4, and 7, characterized in that, Includes the following steps: Step 1: Close the composite switch (3) and the start switch (2) in sequence. The battery (1) supplies power to each component. After the controller (4) and the handle (13) are powered on, they communicate and connect to start the vehicle. Step 2: By pressing down the handle (13), the interlock switch (5) is closed by sensing. Rotating the accelerator (133) of the handle (13) triggers the forward or backward acceleration signal. Operating the lifting switch (131) or the lowering switch (132) controls the lifting or lowering action of the gantry (18) respectively. Step 3: When the pedal (19) is open and no one is standing, the controller (4) receives a signal from the station board sensing switch (12) that it is in the closed state, and the signal from the OPS switch (8) that it is in the open state. The whole vehicle does not perform driving, lifting, or lowering actions. Step 4: When the pedal (19) is open and someone is standing, the guard arm (20) is opened. The controller (4) receives the station board sensing switch (12), the OPS switch (8), and the guard arm protection switch (11) signals, all of which are in a closed state. Step 2 is executed, and the whole vehicle moves and lifts and lowers. Step 5: When the pedal (19) is open and someone is standing, the guard arm (20) is retracted. The controller (4) receives the station board sensing switch (12) signal and the OPS switch (8) signal. The guard arm protection switch (11) signal is in the closed state. Step 2 is executed, and the whole vehicle moves and lifts and lowers. Step 6: When the pedal (19) is retracted and no one is standing, the guard arm (20) is opened. The signal received by the controller (4) from the station board sensing switch (12) and the signal from the OPS switch (8) are in the open state, and the signal from the guard arm protection switch (11) is in the closed state. Step 2 is executed, and the whole vehicle does not perform any driving, lifting, or lowering actions. Step 7: The pedal (19) is retracted and no one is standing. The guard arm (20) is retracted. The controller (4) receives the signals from the station board sensing switch (12), the OPS switch (8), and the guard arm protection switch (11), all of which are in the off state. Step 2 is executed, and the whole vehicle moves and lifts and lowers.

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