Forklift type aerial work platform and control method thereof

Abstract

The present invention discloses a fork-lift type aerial work platform and a control method for the fork-lift type aerial work platform. The fork-lift type aerial work platform includes a platform main body, a lifting device, a lifting drive device, a fork, a control module and a pressure detection member; the control module is configured to: obtain pressure information, determine the position information of the fork, output a first control instruction when the pressure information meets a preset pressure rule, and output a second control instruction when the position information of the fork meets a preset position rule; the lifting drive device is configured to control the lifting device to stop outputting based on the first control instruction so that the fork remains in the current retracted state; control the lifting device to output a negative torque based on the second control instruction, and control the lifting device to stop outputting when the current negative torque reaches a preset negative torque and maintains for a preset duration so that the fork remains in the current retracted state. By adopting the above solution, the problem that it is difficult for the fork to prevent deformation caused by excessive contraction tension while retracting to the end is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of lifting mechanical equipment, and in particular, to a fork-type aerial work platform and a control method for a fork-type aerial work platform. Background Art

[0002] The fork-type aerial work platforms currently used in the market generally include a lifting device and multiple forks. The forks can be raised, unfolded, and contracted in the vertical direction. The lifting device is used to drive the forks to be raised, unfolded, or contracted in the vertical direction. The lifting device generally includes one or more of a lifting hydraulic cylinder and a lifting motor.

[0003] For the existing fork-type aerial work platforms, if the forks are contracted excessively, it will cause the deformation of the forks. After a long time, it will cause hard deformation of the forks, resulting in the force of the forks shifting or even breaking, and at the same time, it will also cause the lifting device to be subjected to excessive pulling force, reducing the service life or even damaging it. In order to prevent excessive contraction, some control logics of the fork-type aerial work platform may limit the output of negative torque and let the forks fall by their own gravity. However, the frictional resistance of each vehicle is different. If the negative torque is removed and the lifting cylinder is prohibited from pulling down, there may be a possibility that the forks cannot be contracted to the bottom. Summary of the Invention

[0004] The present invention provides a fork-type aerial work platform and a control method for a fork-type aerial work platform to solve the problem that it is difficult for the forks to be contracted to the bottom while preventing deformation caused by excessive contraction pulling force.

[0005] According to an aspect of the present invention, there is provided a fork-type aerial work platform, which includes a platform main body, a lifting device, a lifting driving device, a fork, a control module, and a pressure detection member;

[0006] The fork, the lifting device, the lifting driving device, and the control module are all arranged on the platform main body. The lifting device is used to drive the fork to be unfolded or contracted in the vertical direction;

[0007] The pressure detection member is arranged on the fork and is used to detect the pressure information of the fork;

[0008] The input end of the control module is electrically connected to the pressure detection member, and the output end of the control module is electrically connected to the lifting driving device. The control module is used to: acquire the pressure information, determine the position information of the fork, and output a first control instruction when the pressure information meets a preset pressure rule, and output a second control instruction when the position information of the fork meets a preset position rule;

[0009] The lifting drive device is electrically connected to the lifting device. The lifting drive device is configured to control the lifting device to stop output based on the first control instruction, so that the forklift carriage remains in the current contracted state; control the lifting device to output negative torque based on the second control instruction, and control the lifting device to stop output when the current negative torque reaches a preset negative torque and maintains for a preset duration, so that the forklift carriage remains in the current contracted state; the lifting device is configured to feedback the lifting operation parameters to the control module through the lifting drive device.

[0010] In an alternative embodiment of the present invention, the lifting device includes a lifting motor;

[0011] Specifically, the control module is configured to: obtain the total platform load weight, the lifting motor reduction ratio, the lead screw pitch, and the lifting motor efficiency, and determine the position information of the forklift carriage based on the total platform load weight, the motor reduction ratio, the lead screw pitch, the lifting motor efficiency, and the maximum output torque.

[0012] In an alternative embodiment of the present invention, the position information includes the angle of the lifting motor when the forklift carriage contracts;

[0013] Specifically, the control module is configured to: determine the angle of the lifting motor when the forklift carriage contracts through the mathematical relationship of the following formula based on the total platform load weight, the motor reduction ratio, the lead screw pitch, the lifting motor efficiency, and the maximum output torque:

[0014] F max =M 总 *9.8*2 / sinθ;

[0015] F max =T max *η*2π*R / L;

[0016] Wherein, M 总 is the total platform load weight, R is the motor reduction ratio, L is the lead screw pitch, η is the lifting motor efficiency, T max is the maximum output torque, θ is the angle of the lifting motor when the forklift carriage contracts; F max is the maximum thrust required for lifting.

[0017] In an alternative embodiment of the present invention, the lifting device includes a lifting motor, and the lifting operation parameters include motor current, motor voltage, and motor speed; specifically, the control module is configured to: determine the motor power based on the motor current and the motor voltage, and determine the maximum output torque based on the motor power and the motor speed; and / or,

[0018] The control module is specifically configured to: determine the preset negative torque based on the maximum output torque through the following formula: T 反 =T max / 5, where T max is the maximum output torque, and T 反 is the preset negative torque.

[0019] According to another aspect of the present invention, there is provided a control method for a fork-lift type aerial work platform, which is used for the fork-lift type aerial work platform described in any embodiment of the present invention. The control method includes:

[0020] Obtain the pressure information of the fork detected by the pressure detection component and the preset negative torque;

[0021] When the pressure information meets the preset pressure rule, output a first control instruction to make the lifting drive device control the lifting device to stop output based on the first control instruction, so that the fork remains in the current retracted state;

[0022] Determine the position information of the fork;

[0023] When the position information of the fork meets the preset position rule, output a second control instruction to make the lifting drive device control the lifting device to output a negative torque based on the second control instruction, and when the current negative torque reaches the preset negative torque and maintains for a preset duration, make the lifting drive device control the lifting device to stop output, so that the fork remains in the current retracted state.

[0024] In an alternative embodiment of the present invention, the step of "when the pressure information meets the preset pressure rule, output a first control instruction" includes:

[0025] Obtain a preset pressure threshold;

[0026] When the pressure information is greater than the preset pressure threshold, output a first control instruction.

[0027] In an alternative embodiment of the present invention, the step of "when the position information of the fork meets the preset position rule, output a second control instruction" includes:

[0028] When the distance between the position information and the standard storage position is less than a preset distance, output a second control instruction.

[0029] In an alternative embodiment of the present invention, obtaining the preset negative torque includes:

[0030] Obtain the lifting operation parameters;

[0031] Determine the maximum output torque based on the lifting operation parameters, and determine the preset negative torque based on the maximum output torque.

[0032] In an alternative embodiment of the present invention, obtaining a preset pressure threshold includes:

[0033] Obtaining the total weight of the platform load;

[0034] Determining the preset pressure threshold based on the total weight of the platform load.

[0035] In an alternative embodiment of the present invention, determining the preset pressure threshold based on the total weight of the platform load includes:

[0036] Determining the preset pressure threshold based on the total weight of the platform load through the following formula:

[0037] P 限制 = M 总 / 10, where M 总 is the total weight of the platform load, and P 限制 is the preset pressure threshold.

[0038] In the technical solution of the embodiment of the present invention, the control module obtains the pressure information and determines the position information of the fork. When the pressure information meets the preset pressure rule, a first control instruction is output. When the position information of the fork meets the preset position rule, a second control instruction is output. Then, the lifting drive device controls the lifting device to stop output based on the first control instruction, so that the fork remains in the current retracted state. The lifting drive device controls the lifting device to output negative torque based on the second control instruction, and controls the lifting device to stop output when the current negative torque reaches the preset negative torque and maintains the preset duration, so that the fork remains in the current retracted state. Thus, when the friction between the forks is large and the forks cannot be retracted in place by their own gravity, it is possible to pull down the forks by outputting negative torque of the lifting device to make the forks retract in place while preventing the lifting device from continuously pulling down the forks, resulting in excessive tension. When the friction between the forks is small and the forks can be retracted in place by their own gravity, when the pressure information meets the preset pressure rule, the forks can be prevented from continuing to retract. Therefore, the forks can be retracted in place and prevent excessive retraction tension from damaging the forks. Therefore, the problem that it is difficult for the forks to retract to the bottom while preventing excessive retraction tension from causing deformation is solved. The service life of the aerial work platform with forks is increased, which is of great significance to the sustainable development of the industry and resource conservation.

[0039] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0041] Figure 1 is a schematic structural diagram of a fork-lift type aerial work platform provided in Embodiment 1 of the present invention;

[0042] Figure 2 is Figure 1 an enlarged schematic view of part A in

[0043] Figure 3 is a diagram of the information flow transmission path of a fork-lift type aerial work platform provided in Embodiment 1 of the present invention;

[0044] Figure 4 is a flowchart of a control method for a fork-lift type aerial work platform provided in Embodiment 2 of the present invention;

[0045] Figure 5 is a flowchart of a control method for a fork-lift type aerial work platform provided in Embodiment 3 of the present invention.

[0046] Among them: 1, platform main body; 2, lifting device; 3, lifting drive device; 4, fork; 6, control module; 7, pressure detection component. Detailed implementation manners

[0047] In order to enable those skilled in the art to better understand the solutions of the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, rather than all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0048] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of the present invention are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0049] Embodiment 1

[0050] Figure 1 FIG. is a schematic structural diagram of a fork-lift type aerial work platform provided by Embodiment 1 of the present invention. As Figure 1 and Figure 2 shown, the fork-lift type aerial work platform includes a platform main body 1, a lifting device 2, a lifting drive device 3, a fork 4, a control module 6 and a pressure detection member 7. Among them, the platform main body 1 refers to the main part of the fork-lift type aerial work platform. The fork 4, the lifting device 2, the lifting drive device 3 and the control module 6 are all arranged on the platform main body 1.

[0051] The lifting device 2 is used to drive the fork 4 to expand or contract in the vertical direction. When the fork 4 expands, the fork-lift type aerial work platform rises. When the fork 4 contracts and retracts, the fork-lift type aerial work platform descends. The lifting device 2 refers to a device that can drive the fork 4 to expand or contract in the vertical direction. In some embodiments, the lifting device 2 includes one or more of a lifting hydraulic cylinder and a lifting motor. In this embodiment, the lifting device 2 includes a lifting motor, but this is only an example. In other embodiments, the lifting device 2 can also adopt other devices that can drive the fork 4 to expand or contract in the vertical direction.

[0052] The pressure detection member 7 is arranged on the fork 4 and is used to detect the pressure information of the fork 4; among them, the pressure information of the fork 4 refers to the pressure borne by the fork 4 when it is folded, that is, the folding pressure or folding stress. The pressure detection member 7 can be arranged at the connection of the fork 4, such as positions like hinges and pin shafts, and can directly measure the pressure generated during the folding process. The pressure detection member 7 can also be arranged at some key stress points of the fork 4, such as the ends of the support arms and the corners of the folding parts. These positions are also ideal positions where the pressure detection member 7 can be arranged and can accurately reflect the stress situation of the fork 4 during the folding process. The specific structure of the pressure detection member 7 is not specifically limited here, only for illustration. In some embodiments, the pressure detection member 7 includes a pressure sensor, so as to conveniently detect the pressure information of the fork 4.

[0053] As Figure 1 and Figure 3 shown, the input end of the control module 6 is electrically connected to the pressure detection component 7, and the output end of the control module 6 is electrically connected to the lifting drive device 3. The lifting drive device 3 refers to a device that can drive the lifting device 2 to work. In some embodiments, the lifting device 2 includes a lifting motor, and the corresponding lifting drive device 3 is a motor driver. By changing the parameters of the current or voltage input to the lifting motor, the motor driver can control the rotation speed and direction of the lifting motor, and further control the lifting motor to drive the fork 4 to expand or contract in the vertical direction.

[0054] The control module 6 is configured to: obtain pressure information, determine the position information of the fork 4, output a first control instruction when the pressure information meets a preset pressure rule, and output a second control instruction when the position information of the fork 4 meets a preset position rule. Among them, the control module 6 refers to a functional module that can perform logical control. In some embodiments, the control module 6 includes a microprocessor. In other embodiments, other devices can also be used for control, such as one of PLC, DSP, and FPGA, which is not specifically limited here, but only for illustration. The position information of the fork 4 refers to the information reflecting the current contraction position of the fork 4. The standard storage position refers to the contraction position of the fork 4 when the fork 4 is fully contracted and not over-contracted. When the position information of the fork 4 reaches the standard storage position, it means that the fork 4 has been stored in place. The preset position rule refers to the situation where the position where the fork 4 stops contracting under its own gravity is not the standard storage position.

[0055] The lifting drive device 3 is electrically connected to the lifting device 2, and the lifting drive device 3 is configured to control the lifting device 2 to stop output based on the first control instruction, so that the fork 4 remains in the current contraction state; wherein, the first control instruction refers to an electrical signal used to control the lifting drive device 3, and the current contraction state refers to the contraction state where the fork 4 is located at this time. When the lifting device 2 stops output, the lifting device 2 no longer operates, so that the fork 4 also no longer operates and remains in the current contraction state without continuing to contract. If the friction between the forks 4 is small, the forks 4 can be stored in place by their own gravity. By making the forks 4 no longer continue to contract when the pressure information meets the preset pressure rule, it is possible to prevent the forks 4 from being damaged due to excessive pulling force caused by over-contraction.

[0056] The lifting drive device 3 is further configured to control the lifting device 2 to output a negative torque based on a second control instruction, and to control the lifting device 2 to stop outputting when the current negative torque reaches a preset negative torque and maintains for a preset duration, so that the fork carriage 4 is kept in the current contracted state. Herein, the second control instruction refers to an electrical signal for controlling the lifting drive device 3. When the lifting device 2 outputs a negative torque, the fork carriage 4 will continue to contract under the action of the negative torque. The current negative torque refers to the negative torque currently output by the lifting device 2, the preset negative torque refers to the maximum value that the negative torque output by the lifting device 2 should not exceed when the fork carriage 4 does not contract excessively, and the preset duration is the duration for which the preset negative torque should be maintained and output in advance. If the friction force between the fork carriages 4 is large and the fork carriage 4 cannot be retracted in place by its own gravity, by controlling the lifting device 2 to output a negative torque when the position information of the fork carriage 4 meets the preset position rule, and controlling the lifting device 2 to stop outputting when the current negative torque reaches the preset negative torque and maintains for the preset duration, it is possible to make the fork carriage 4 retract in place while preventing the lifting device 2 from continuously pulling down the fork carriage 4, resulting in excessive pulling force.

[0057] In the above solution, the control module 6 obtains the pressure information to determine the position information of the fork carriage 4. When the pressure information meets the preset pressure rule, a first control instruction is output. When the position information of the fork carriage 4 meets the preset position rule, a second control instruction is output. Then, the lifting drive device 3 controls the lifting device 2 to stop outputting based on the first control instruction, so that the fork carriage 4 is kept in the current contracted state. The lifting drive device 3 controls the lifting device 2 to output a negative torque based on the second control instruction, and controls the lifting device 2 to stop outputting when the current negative torque reaches the preset negative torque and maintains for the preset duration, so that the fork carriage 4 is kept in the current contracted state. Thus, when the friction force between the fork carriages 4 is large and the fork carriage 4 cannot be retracted in place by its own gravity, it is possible to prevent the lifting device 2 from continuously pulling down the fork carriage 4, resulting in excessive pulling force, while pulling down the fork carriage 4 by outputting a negative torque from the lifting device 2 to make the fork carriage 4 retract in place. When the friction force between the fork carriages 4 is small and the fork carriage 4 can be retracted in place by its own gravity, when the pressure information meets the preset pressure rule, it is possible to prevent the fork carriage 4 from continuing to contract. Therefore, the fork carriage 4 can be retracted in place and prevent excessive contraction of the fork carriage 4, resulting in excessive pulling force and damage to the fork carriage 4. Therefore, the problem that it is difficult for the fork carriage 4 to prevent excessive contraction pulling force and deformation while retracting to the bottom is solved. The service life of the aerial work platform with fork carriages is increased, which is of great significance to the sustainable development of the industry and resource conservation.

[0058] In an alternative embodiment of the present invention, as Figures 1-3As shown, the control module 6 is specifically configured to: when the pressure information is greater than a preset pressure threshold, output a first control instruction. The preset pressure threshold refers to the value that the pressure information is greater than when the fork rest 4 is fully retracted. When the pressure is too high, the fork rest 4 may be damaged. By outputting the first control instruction when the pressure information is greater than the preset pressure threshold, the fork rest 4 can be stopped from retracting when the pressure information is too high. Therefore, the fork rest 4 can be fully retracted and the fork rest 4 can be prevented from being damaged due to excessive pulling force caused by over-retraction.

[0059] In an alternative embodiment of the present invention, the control module 6 is specifically configured to: when the distance between the position information and the standard retracted position is less than a preset distance, output a second control instruction. The standard retracted position refers to the value that the position information will be when the fork rest 4 is fully retracted. When the distance between the position information and the standard retracted position is less than the preset distance, it means that the fork rest 4 is close to being fully retracted at this time. If the friction between the fork rests 4 is large, the fork rest 4 cannot be fully retracted by its own gravity. When the fork rest 4 is close to being fully retracted, the lifting device 2 applies a negative torque to pull down the fork rest 4 to make the fork rest 4 continue to retract until the negative torque increases to a preset negative torque and maintains the preset duration, and then controls the lifting device 2 to stop outputting, so that the fork rest 4 remains in the current retracted state, preventing the fork rest 4 from being continuously pulled down, thereby making the fork rest 4 fully retracted while preventing the lifting device 2 from continuously pulling down the fork rest 4 resulting in excessive pulling force.

[0060] In an alternative embodiment of the present invention, as Figures 1-3 shown, the lifting device 2 is configured to feedback the lifting operation parameters to the control module 6 through the lifting drive device 3; the control module 6 is specifically configured to: determine the maximum output torque based on the lifting operation parameters, and determine the preset negative torque based on the maximum output torque. The lifting operation parameters refer to the relevant parameters when the lifting device 2 is operating. In some embodiments, the lifting device 2 includes a lifting motor, and the lifting operation parameters include the motor current, the motor voltage, and the motor speed. The motor current refers to the working current of the lifting motor, the motor voltage refers to the working voltage of the lifting motor, and the motor speed refers to the rotational speed output by the lifting motor. The maximum output torque refers to the maximum torque output by the lifting device 2.

[0061] When the maximum output torque of the lifting device 2 is different, with a fixed preset duration, even if the preset negative torque is the same, the degree to which the lower fork 4 is pulled down during the process from the start of applying the negative torque to the stop of output by the lifting device 2 is different. When the preset duration is fixed and the maximum output torque of the lifting device 2 is the same, with different values of the preset negative torque, the degree to which the lower fork 4 is pulled down during the process from the start of applying the negative torque to the stop of output by the lifting device 2 will also be different. Therefore, the changes in the values of the maximum output torque and the preset negative torque will both affect the degree to which the lower fork 4 is pulled down during the process from the start of applying the negative torque to the stop of output by the lifting device 2. By determining the preset negative torque based on the maximum output torque, the degree to which the lower fork 4 is pulled down when the lifting device 2 applies the negative torque can be better controlled, so that while the fork 4 can be better stored in place, it can prevent the lifting device 2 from continuously pulling down the fork 4, resulting in excessive tension and damage to the fork 4.

[0062] Based on the above embodiments, as Figures 1-3 shown, the lifting device 2 includes a lifting motor, and the lifting operation parameters include motor current, motor voltage, and motor speed; the control module 6 is specifically configured to: determine the motor power based on the motor current and motor voltage, and determine the maximum output torque based on the motor power and the motor speed. Among them, the control module 6 is specifically configured to: determine the motor power based on the following formula of the motor current and motor voltage: P 功率 =U*I, where I is the motor current, U is the motor voltage, and P 功率 is the motor power; determine the maximum output torque based on the motor power and the motor speed through the following mathematical relationship: P power = T max *n speed / 9549, where T max is the maximum output torque and n speed is the motor speed.

[0063] In an alternative embodiment of the present invention, the control module 6 is specifically configured to: determine the preset negative torque based on the maximum output torque through the following formula: T 反 =T max / 5, where T max is the maximum output torque and T 反 is the preset negative torque. Among them, through this formula, the preset negative torque can be accurately calculated based on the maximum output torque, and the degree to which the lower fork 4 is pulled down when the lifting device 2 applies the negative torque can be better controlled, so that while the fork 4 can be better stored in place, it can prevent the lifting device 2 from continuously pulling down the fork 4, resulting in excessive tension and damage to the fork 4.

[0064] In an alternative embodiment of the present invention, as Figures 1-3As shown in the figure, the lifting device 2 includes a lifting motor; the control module 6 is specifically configured to: obtain the total platform load weight, the reduction ratio of the lifting motor, the lead of the screw rod, and the efficiency of the lifting motor, and determine the position information of the fork 4 based on the total platform load weight, the motor reduction ratio, the lead of the screw rod, the efficiency of the lifting motor, and the maximum output torque. Among them, the total platform load weight refers to the total weight of the fork 4, the platform main body 1, and the load. The reduction ratio of the lifting motor refers to the ratio of the rotational speed of the input shaft (usually the motor shaft) to the rotational speed of the output shaft (usually the load shaft). The lifting device 2 further includes a screw rod assembly, and the screw rod assembly includes a ball screw and a ball nut. The lead of the screw rod refers to the stroke when the ball nut rotates 2π radians relative to the ball screw. In the lifting device 2, the size of the lead of the screw rod determines the accuracy and efficiency of the lifting device 2. The larger the lead, the greater the displacement of the ball screw per revolution, and thus the faster the lifting speed. The efficiency of the lifting motor refers to the efficiency of the lifting motor in converting the input electrical energy into mechanical energy during operation. The total platform load weight, the reduction ratio of the lifting motor, the lead of the screw rod, the efficiency of the lifting motor, and the maximum output torque jointly affect the position of the fork 4. Therefore, the position information of the fork 4 can be determined according to the total platform load weight, the motor reduction ratio, the lead of the screw rod, the efficiency of the lifting motor, and the maximum output torque.

[0065] Based on the above embodiments, the position information includes the angle of the lifting motor when the fork 4 contracts; among them, the angle of the lifting motor refers to the angle of the lifting motor during the working stroke. When the fork 4 contracts, the degree of contraction of the fork 4 is different, and the angle of the lifting motor will be different. Therefore, the angle of the lifting motor can reflect the position of the fork 4. The control module 6 is specifically configured to: determine the angle of the lifting motor when the fork 4 contracts through the mathematical relationship of the following formula based on the total platform load weight, the motor reduction ratio, the lead of the screw rod, the efficiency of the lifting motor, and the maximum output torque: F max =M 总 *9.8*2 / sinθ; F max =T max *η*2π*R / L; where M 总 is the total platform load weight, R is the motor reduction ratio, L is the lead of the screw rod, η is the efficiency of the lifting motor, T max is the maximum output torque, θ is the angle of the lifting motor when the fork 4 contracts; F max is the maximum thrust required for lifting. Through the above mathematical relationship, since other values are known, the angle of the lifting motor when the fork 4 contracts can be easily calculated, and the accurate position information of the fork 4 can be obtained.

[0066] In an alternative embodiment of the present invention, as Figures 1-3As shown, the control module 6 is specifically configured to: obtain the total platform load weight, and determine a preset pressure threshold based on the total platform load weight. Among them, under different total platform load weights, the maximum pressure that the fork 4 can bear is also different. By determining the preset pressure threshold based on the total platform load weight, the preset pressure threshold can be made more in line with the actual situation of the fork 4, and it can better ensure that the fork 4 will not be deformed due to excessive contraction tension when it contracts to the bottom.

[0067] Based on the above embodiments, the control module 6 is specifically configured to: determine the preset pressure threshold based on the total platform load weight through the following formula: P 限制 =M 总 / 10, where M 总 is the total platform load weight, and P 限制 is the preset pressure threshold. Through the above formula, the preset pressure threshold can be conveniently calculated according to the total platform load weight, and the obtained preset pressure threshold is more accurate.

[0068] In an alternative embodiment of the present invention, the fork-type aerial work platform further includes a power source, and the power source includes a battery. The battery is electrically connected to the lifting drive device 3 and is used to provide a DC working power supply.

[0069] In some embodiments, the lifting device 2 further includes a rotation speed detection component, and the rotation speed detection component is used to detect the motor rotation speed of the lifting motor. In some embodiments, the rotation speed detection component includes at least one of a Hall sensor and an encoder.

[0070] Embodiment 2

[0071] Figure 4 The following is a flowchart of a control method for a fork-type aerial work platform provided in Embodiment 2 of the present invention. The control method for the fork-type aerial work platform is used for the fork-type aerial work platform described in any embodiment of the present invention, and the control method for the fork-type aerial work platform can be executed by the control module of the fork-type aerial work platform. As Figure 4 shown, the control method for the fork-type aerial work platform includes:

[0072] S110. Obtain the pressure information of the fork detected by the pressure detection component.

[0073] Among them, the pressure information of the fork support refers to the pressure borne by the fork support during folding, that is, the folding pressure or folding stress. The pressure detection component can be arranged at the connection of the fork support, such as positions like hinges and pin shafts, and can directly measure the pressure generated during the folding process. The pressure detection component can also be arranged at some key stress points of the fork support, such as the ends of the support arms and the corners of the folding parts. These positions are also ideal positions where the pressure detection component can be arranged and can accurately reflect the stress condition of the fork support during folding. No specific limitation is made on the specific structure of the pressure detection component here, only for illustrative purposes. In some embodiments, the pressure detection component includes a pressure sensor, so as to conveniently detect the pressure information of the fork support.

[0074] S120. When the pressure information meets the preset pressure rule, output a first control instruction to enable the lifting drive device to control the lifting device to stop outputting based on the first control instruction, so that the fork support remains in the current contracted state.

[0075] Among them, the first control instruction refers to the electrical signal used to control the lifting drive device, and the current contracted state refers to the contracted state where the fork support is at this time. When the lifting device stops outputting, the lifting device no longer operates, so the fork support also no longer operates and remains in the current contracted state without continuing to contract. If the friction between the fork supports is small, the fork support can be retracted in place by its own gravity. By making the fork support no longer continue to contract when the pressure information meets the preset pressure rule, it can prevent the fork support from being damaged due to excessive contraction resulting in excessive pulling force.

[0076] S130. Determine the position information of the fork support.

[0077] Among them, the position information of the fork support refers to the information reflecting the current contracted position of the fork support.

[0078] S140. When the position information of the fork support meets the preset position rule, output a second control instruction to enable the lifting drive device to control the lifting device to output negative torque based on the second control instruction, and when the current negative torque reaches the preset negative torque and maintains for a preset duration, enable the lifting drive device to control the lifting device to stop outputting, so that the fork support remains in the current contracted state.

[0079] Among them, the preset position rule refers to the situation where the position where the fork support stops contracting under the action of its own gravity does not meet the standard storage position. The second control instruction refers to the electrical signal used to control the lifting drive device. When the lifting device outputs a negative torque, the fork support will continue to contract under the action of the negative torque. The current negative torque refers to the negative torque currently output by the lifting device, and the preset negative torque refers to the maximum value that the negative torque output by the lifting device should not exceed when the fork support does not contract excessively. The preset duration is the duration that the preset negative torque should be maintained and output in advance. If the friction between the fork supports is large and the fork support cannot be stored in place by its own gravity, by controlling the lifting device to output a negative torque when the position information of the fork support meets the preset position rule, and controlling the lifting device to stop output when the current negative torque reaches the preset negative torque and maintains the preset duration, it is possible to make the fork support be stored in place while preventing the lifting device from continuously pulling down the fork support, resulting in excessive tensile force.

[0080] In the above solution, by obtaining the pressure information of the fork support detected by the pressure detection component, when the pressure information meets the preset pressure rule, a first control instruction is output, so that the lifting drive device controls the lifting device to stop output based on the first control instruction, so that the fork support remains in the current contracted state. When the friction between the fork supports is small and the fork support can be stored in place by its own gravity, when the pressure information meets the preset pressure rule, the fork support can be prevented from continuing to contract, so the fork support can not only be stored in place but also prevent the fork support from being damaged due to excessive contraction and excessive tensile force. By determining the position information of the fork support, when the position information of the fork support meets the preset position rule, a second control instruction is output, so that the lifting drive device controls the lifting device to output a negative torque based on the second control instruction, and when the current negative torque reaches the preset negative torque and maintains the preset duration, the lifting drive device controls the lifting device to stop output, so that the fork support remains in the current contracted state. Thus, when the friction between the fork supports is large and the fork support cannot be stored in place by its own gravity, it is possible to prevent the lifting device from continuously pulling down the fork support, resulting in excessive tensile force, while pulling down the fork support by outputting a negative torque through the lifting device to make the fork support be stored in place. Therefore, the problem that it is difficult for the fork support to prevent excessive contraction tensile force from causing deformation while contracting to the bottom is solved. The service life of the aerial work platform with fork supports is increased, which is of great significance to the sustainable development of the industry and resource conservation.

[0081] Embodiment III

[0082] Embodiment 3 of the present invention provides a control method for a fork-type aerial work platform. This embodiment improves Embodiment 2. Optionally, when the pressure information satisfies a preset pressure rule, a first control instruction is output, including: when the pressure information is greater than a preset pressure threshold, a first control instruction is output. Optionally, when the position information of the fork satisfies a preset position rule, a second control instruction is output, including: when the distance between the position information and the standard storage position is less than a preset distance, a second control instruction is output. Based on this, as Figure 5 shown, the control method of the fork-type aerial work platform includes:

[0083] S210. Obtain the pressure information of the fork detected by the pressure detector.

[0084] S220. When the pressure information is greater than a preset pressure threshold, output a first control instruction, so that the lifting drive device controls the lifting device to stop output based on the first control instruction, so that the fork remains in the current retracted state.

[0085] Wherein, the preset pressure threshold refers to the value greater than which the pressure information is when the fork is fully stored. When the pressure is too high, the fork may be damaged. By outputting a first control instruction when the pressure information is greater than the preset pressure threshold, the fork can be stopped from retracting when the pressure information is too high. Therefore, the fork can be fully stored and the fork can be prevented from being damaged due to excessive pulling force caused by excessive retraction.

[0086] S230. Determine the position information of the fork.

[0087] S240. When the distance between the position information and the standard storage position is less than a preset distance, output a second control instruction, so that the lifting drive device controls the lifting device to output negative torque based on the second control instruction, and when the current negative torque reaches the preset negative torque and maintains the preset duration, the lifting drive device controls the lifting device to stop output, so that the fork remains in the current retracted state.

[0088] Wherein, the standard storage position refers to the retracted position of the fork when the fork is fully retracted and not over-retracted. When the position information of the fork reaches the standard storage position, it means that the fork has been fully stored. When the distance between the position information and the standard storage position is less than a preset distance, it means that the fork is close to being fully stored at this time. If the friction between the forks is large, the fork cannot be fully stored by its own gravity. When the fork is close to being fully stored, the lifting device applies negative torque to pull down the fork to make the fork continue to retract until the negative torque increases to the preset negative torque and maintains the preset duration, and then controls the lifting device to stop output, so that the fork remains in the current retracted state, preventing the fork from being continuously pulled down, so that the fork can be fully stored while preventing the lifting device from continuously pulling down the fork, resulting in excessive pulling force.

[0089] In an alternative embodiment of the present invention, before outputting the second control instruction when the distance between the position information and the standard storage position is less than a preset distance, the method further includes: obtaining the lifting operation parameters fed back by the lifting device, determining the maximum output torque based on the lifting operation parameters, and determining the preset negative torque based on the maximum output torque. The lifting operation parameters refer to the relevant parameters during the operation of the lifting device. In some embodiments, the lifting device includes a lifting motor, and the lifting operation parameters include motor current, motor voltage, and motor speed. The motor current refers to the working current of the lifting motor, the motor voltage refers to the working voltage of the lifting motor, and the motor speed refers to the rotational speed output by the lifting motor. The maximum output torque refers to the maximum torque output by the lifting device.

[0090] When the maximum output torques of the lifting devices are different, with a fixed preset duration, even if the preset negative torques are the same, the degree of pulling down the lower fork during the process of the lifting device starting to apply the negative torque until it stops outputting is different. And when the preset duration is fixed and the maximum output torques of the lifting devices are the same, with different values of the preset negative torque, the degree of pulling down the lower fork during the process of the lifting device starting to apply the negative torque until it stops outputting is also different. Therefore, the changes in the values of the maximum output torque and the preset negative torque will both affect the degree of pulling down the lower fork during the process of the lifting device starting to apply the negative torque until it stops outputting. By determining the preset negative torque based on the maximum output torque, the degree of pulling down the lower fork when the lifting device applies the negative torque can be better controlled, so that the fork can be better stored in place while preventing the lifting device from continuously pulling down the lower fork, resulting in excessive tension and damage to the lower fork.

[0091] In an alternative embodiment of the present invention, the lifting device includes a lifting motor, and the lifting operation parameters include motor current, motor voltage, and motor speed; determining the maximum output torque based on the lifting operation parameters includes: determining the motor power based on the motor current and the motor voltage, and determining the maximum output torque based on the motor power and the motor speed.

[0092] Among them, the control module is specifically configured to: determine the motor power based on the motor current and the motor voltage according to the following formula: P 功率 =U*I, where I is the motor current, U is the motor voltage, and P 功率 is the motor power; determine the maximum output torque based on the motor power and the motor speed through the following mathematical relationship: P 功率 =T max *n 转速 / 9549, where T max is the maximum output torque, and n 转速 is the motor speed.

[0093] In an alternative embodiment of the present invention, determining the preset negative torque based on the maximum output torque includes: determining the preset negative torque based on the maximum output torque through the following formula: T 反 =T max / 5, where T max is the maximum output torque, and T 反 is the preset negative torque. Among them, through this formula, the preset negative torque can be accurately calculated according to the maximum output torque, which can better control the degree of pulling down the fork frame when the lifting device applies a negative torque, so that the fork frame can be better collected in place while preventing the lifting device from continuously pulling down the fork frame, resulting in excessive tension and damage to the fork frame.

[0094] In an alternative embodiment of the present invention, the lifting device includes a lifting motor; determining the position information of the fork frame includes: obtaining the total platform load weight, the reduction ratio of the lifting motor, the lead of the screw rod, and the efficiency of the lifting motor, and determining the position information of the fork frame based on the total platform load weight, the motor reduction ratio, the lead of the screw rod, the efficiency of the lifting motor, and the maximum output torque.

[0095] Among them, the total platform load weight refers to the total weight of the fork frame, the platform body, and the load. The reduction ratio of the lifting motor refers to the ratio of the rotational speed of the input shaft (usually the motor shaft) to the rotational speed of the output shaft (usually the load shaft). The lifting device further includes a screw rod assembly, and the screw rod assembly includes a ball screw and a ball nut. The lead of the screw rod refers to the stroke when the ball nut rotates 2π radians relative to the ball screw. In the lifting device, the size of the lead of the screw rod determines the accuracy and efficiency of the lifting device. The larger the lead, the greater the displacement of the ball screw per revolution, and thus the faster the lifting speed. The efficiency of the lifting motor refers to the efficiency of the lifting motor in converting the input electrical energy into mechanical energy during operation. The total platform load weight, the reduction ratio of the lifting motor, the lead of the screw rod, the efficiency of the lifting motor, and the maximum output torque jointly affect the position of the fork frame, so the position information of the fork frame can be determined according to the total platform load weight, the motor reduction ratio, the lead of the screw rod, the efficiency of the lifting motor, and the maximum output torque.

[0096] Based on the above embodiment, the position information includes the angle of the lifting motor when the fork frame contracts; among them, the angle of the lifting motor refers to the angle of the lifting motor during the working stroke. When the fork frame contracts, the degree of contraction of the fork frame is different, and the angle of the lifting motor will be different. Therefore, the angle of the lifting motor can reflect the position of the fork frame.

[0097] Determining the position information of the fork frame based on the total platform load weight, the motor reduction ratio, the lead of the lead screw, the efficiency of the lifting motor, and the maximum output torque includes: determining the angle of the lifting motor when the fork frame contracts through the mathematical relationship of the following formula based on the total platform load weight, the motor reduction ratio, the lead of the lead screw, the efficiency of the lifting motor, and the maximum output torque: F max =M 总 *9.8*2 / sinθ; F max =T max *η*2π*R / L; where M 总 is the total platform load weight, R is the motor reduction ratio, L is the lead of the lead screw, η is the efficiency of the lifting motor, T max is the maximum output torque, and θ is the angle of the lifting motor when the fork frame contracts; F max is the maximum thrust required for lifting. Through the above mathematical relationship, since other values are known, the angle of the lifting motor when the fork frame contracts can be easily calculated, and accurate position information of the fork frame can be obtained.

[0098] In an alternative embodiment of the present invention, before outputting the first control instruction when the pressure information meets the preset pressure rule, it further includes: obtaining the total platform load weight and determining the preset pressure threshold based on the total platform load weight. Among them, under different total platform load weights, the maximum pressure that the fork frame can withstand is also different. By determining the preset pressure threshold based on the total platform load weight, the preset pressure threshold can be made more in line with the actual situation of the fork frame, and the fork frame can be better prevented from being deformed due to excessive contraction tension when it contracts to the bottom.

[0099] Based on the above embodiment, determining the preset pressure threshold based on the total platform load weight includes: determining the preset pressure threshold through the following formula based on the total platform load weight: P 限制 =M 总 / 10, where M 总 is the total platform load weight and P 限制 is the preset pressure threshold. Through the above formula, the preset pressure threshold can be easily calculated according to the total platform load weight, and the obtained preset pressure threshold is more accurate.

[0100] It should be understood that various forms of the processes shown above can be used, steps can be reordered, added, or deleted. For example, the steps described in the present invention can be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved, and no limitation is made herein.

[0101] The above specific embodiments do not constitute a limitation on the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub - combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A fork-type aerial work platform, characterized in that: It includes a platform body, a lifting device, a lifting drive device, a fork frame, a control module and a pressure detection component; The fork frame, the lifting device, the lifting drive device and the control module are all arranged on the platform body, and the lifting device is used to drive the fork frame to expand or retract in the vertical direction; The pressure detection member is arranged on the fork frame, and is used to detect the pressure information of the fork frame; The input end of the control module is electrically connected to the pressure detection element, and the output end of the control module is electrically connected to the lifting drive device. The control module is used to: obtain the pressure information, determine the position information of the fork frame, and output a first control instruction when the pressure information meets the preset pressure rule, and output a second control instruction when the position information of the fork frame meets the preset position rule; The lifting drive device is electrically connected to the lifting device, and the lifting drive device is used to control the lifting device to stop output based on the first control instruction, so that the fork frame remains in a current retracted state; Controlling the lifting device to output negative torque based on the second control instruction, and controlling the lifting device to stop outputting negative torque when the current negative torque reaches a preset negative torque and is maintained for a preset time, so that the fork frame remains in a current retracted state; The lifting device is used to feed back lifting operation parameters to the control module through the lifting drive device; The lifting device includes a lifting motor; The control module is specifically used to: obtain the total weight of the platform load, the reduction ratio of the lifting motor, the lead of the screw and the efficiency of the lifting motor, and determine the position information of the fork frame based on the total weight of the platform load, the motor reduction ratio, the lead of the screw, the efficiency of the lifting motor and the maximum output torque; The position information includes the angle of the lifting motor when the fork frame is retracted.

2. The fork-type aerial work platform according to claim 1, characterized in that: The lifting device includes a lifting motor, and the lifting operation parameters include motor current, motor voltage and motor speed; the control module is specifically used to: determine the motor power based on the motor current and the motor voltage, and determine the maximum output torque based on the motor power and the motor speed; and / or, The control module is specifically used to determine the preset negative torque based on the maximum output torque by the following formula: 反 =T max / 5, T max is the maximum output torque, T 反 is the preset negative torque.

3. A control method for a fork-type aerial work platform, characterized in that: For a fork-type aerial work platform according to any one of claims 1 to 2, the control method comprises: Obtaining pressure information of the fork frame detected by the pressure detection component and a preset negative torque; When the pressure information satisfies a preset pressure rule, a first control instruction is outputted, so that the lifting drive device controls the lifting device to stop outputting based on the first control instruction, so that the fork frame is kept in a current retracted state; Determining the position information of the fork; When the position information of the fork frame meets the preset position rule, a second control instruction is output to enable the lifting drive device to control the lifting device to output a negative torque based on the second control instruction, and when the current negative torque reaches the preset negative torque and is maintained for a preset time, the lifting drive device controls the lifting device to stop outputting, so that the fork frame remains in the current retracted state.

4. The control method of the fork-type aerial work platform according to claim 3, characterized in that: When the pressure information satisfies a preset pressure rule, outputting a first control instruction includes: Get the preset pressure threshold; When the pressure information is greater than the preset pressure threshold, a first control instruction is output.

5. The control method of a fork-type aerial work platform according to claim 3, characterized in that: When the position information of the fork frame meets the preset position rule, a second control instruction is output, including: When the distance between the position information and the standard collection position is less than a preset distance, a second control instruction is output.

6. The control method of a fork-type aerial work platform according to claim 3, characterized in that: Acquiring the preset negative torque includes: Get lifting operation parameters; A maximum output torque is determined based on the lifting operation parameter, and the preset negative torque is determined based on the maximum output torque.

7. The control method of a fork-type aerial work platform according to claim 4, characterized in that: Get preset pressure thresholds, including: Get the total weight of the platform load; The preset pressure threshold is determined based on the total weight of the platform load.

8. The control method of a fork-type aerial work platform according to claim 7, characterized in that: Determining the preset pressure threshold based on the total weight of the platform load includes: The preset pressure threshold is determined based on the total weight of the platform load by the following formula: P 限制 =M 总 / 10, where M 总 is the total weight of the platform load, P 限制 is the preset pressure threshold.

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