Fork frame type aerial work platform and control method of fork frame type aerial work platform

Abstract

The invention discloses a fork frame type aerial work platform and a control method of the fork frame type aerial work platform. The fork frame type aerial work platform comprises a platform body, a lifting device, a lifting driving device, a fork frame, a control module and a pressure detection piece. The control module is used for acquiring pressure information, determining position information of the fork frame, outputting a first control instruction when the pressure information meets a preset pressure rule, and outputting a second control instruction when the position information of the fork frame meets a preset position rule; the lifting driving device is used for controlling the lifting device to stop outputting based on the first control instruction, so that the fork frame is kept in the current contraction state; and controlling the lifting device to output negative torque based on the second control instruction, and controlling the lifting device to stop outputting when the current negative torque reaches the preset negative torque and is maintained for a preset duration, so that the fork frame is kept in the current contraction state. By the adoption of the scheme, the problem that deformation caused by too large contraction tension is difficult to prevent while the fork frame is contracted to the bottom is solved.

Description

Technical Field

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

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

[0003] For existing fork-type aerial work platforms, if the fork frame is over-contracted, it will cause the fork frame to deform. After a long time, it will cause the fork frame to be rigidly deformed, causing the fork frame to be offset or even broken. At the same time, it will also cause the lifting device to be subjected to excessive tension, reducing its life or even damaging it. In order to prevent excessive contraction, some control logic of fork-type aerial work platforms may limit the output of negative torque and let the fork frame fall by its own gravity. However, the friction resistance of each vehicle is different. If the negative torque is removed to prohibit the lifting cylinder from pulling down, it may be possible that the fork frame cannot be retracted to the bottom. Summary of the invention

[0004] The present invention provides a fork frame type aerial work platform and a control method for the fork frame type aerial work platform, so as to solve the problem that it is difficult to prevent deformation caused by excessive contraction tension when the fork frame is fully contracted.

[0005] According to one aspect of the present invention, there is provided a fork-frame aerial work platform, the fork-frame aerial work platform comprising a platform body, a lifting device, a lifting drive device, a fork frame, a control module and a pressure detection member;

[0006] 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;

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

[0008] 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;

[0009] The lifting drive device is electrically connected to the lifting device, and 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; 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 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.

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

[0011] The control module is specifically used to obtain the total weight of the platform load, the lifting motor reduction ratio, 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.

[0012] In an optional embodiment of the present invention, the position information includes the angle of the lifting motor when the fork frame is retracted;

[0013] The control module is specifically used to determine the angle of the lifting motor when the fork frame is retracted 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 through the following mathematical relationship:

[0014] F max =M 总 *9.8*2 / sinθ;

[0015] F max =T max *η*2π*R / L;

[0016] Among them, M 总 is the total weight of the platform load, R is the motor reduction ratio, L is the lead of the screw, 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 frame is retracted; F max The maximum thrust required for lifting.

[0017] In an optional 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; 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,

[0018] 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.

[0019] According to another aspect of the present invention, a control method for a fork-frame aerial work platform is provided, which is used for the fork-frame aerial work platform described in any embodiment of the present invention, and the control method comprises:

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

[0021] 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;

[0022] Determining the position information of the fork;

[0023] 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.

[0024] In an optional embodiment of the present invention, when the pressure information satisfies a preset pressure rule, outputting a first control instruction includes:

[0025] Get the preset pressure threshold;

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

[0027] In an optional embodiment of the present invention, when the position information of the fork frame meets the preset position rule, outputting the second control instruction includes:

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

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

[0030] Get lifting operation parameters;

[0031] 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.

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

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

[0034] The preset pressure threshold is determined based on the total weight of the platform load.

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

[0036] The preset pressure threshold is determined based on the total weight of the platform load by the following formula:

[0037] 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.

[0038] The technical solution of the embodiment of the present invention is to obtain the pressure information through the control module, determine the position information of the fork frame, output the first control instruction when the pressure information meets the preset pressure rule, and output the second control instruction when the position information of the fork frame meets the preset position rule; then the lifting drive device controls the lifting device to stop output based on the first control instruction, so that the fork frame 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 time, so that the fork frame remains in the current retracted state. Therefore, when the friction between the forks is large and the fork frame cannot be stored in place by its own gravity, the lifting device can output negative torque to pull down the fork frame so that the fork frame is stored in place, while preventing the lifting device from continuously pulling down the fork frame to cause excessive tension. When the friction between the forks is small and the fork frame can be stored in place by its own gravity, when the pressure information meets the preset pressure rule, the fork frame can stop retracting, so the fork frame can be stored in place and the fork frame can be prevented from being damaged by excessive tension caused by excessive retraction. Therefore, the problem that the fork frame is difficult to retract to the bottom while preventing deformation caused by excessive retraction force is solved. The life of the fork frame aerial work platform is increased, which is of great significance to the sustainable development and resource conservation of the industry.

[0039] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended 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] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0041] Figure 1 It is a structural schematic diagram of a fork-type aerial work platform provided according to the first embodiment of the present invention;

[0042] Figure 2 yes Figure 1 The enlarged schematic diagram of point A in the middle;

[0043] Figure 3 It is an information flow transmission path diagram of a fork-type aerial work platform provided according to the first embodiment of the present invention;

[0044] Figure 4 is a flow chart of a control method for a fork-type aerial work platform provided according to Embodiment 2 of the present invention;

[0045] Figure 5 It is a flow chart of a control method of a fork-type aerial work platform provided according to the third embodiment of the present invention.

[0046] Among them: 1. Platform body; 2. Lifting device; 3. Lifting drive device; 4. Fork frame; 6. Control module; 7. Pressure detection component. DETAILED DESCRIPTION

[0047] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

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

[0049] Embodiment 1

[0050] Figure 1 A schematic diagram of the structure of a fork-type aerial work platform provided in the first embodiment of the present invention is shown in FIG. Figure 1 and Figure 2 As shown, the fork frame aerial work platform includes a platform body 1, a lifting device 2, a lifting drive device 3, a fork frame 4, a control module 6 and a pressure detection component 7. The platform body 1 refers to the main part of the fork frame aerial work platform. The fork frame 4, the lifting device 2, the lifting drive device 3 and the control module 6 are all arranged on the platform body 1.

[0051] The lifting device 2 is used to drive the fork frame 4 to expand or contract in the vertical direction. When the fork frame 4 is expanded, the fork frame aerial work platform rises, and when the fork frame 4 is retracted and stored, the fork frame aerial work platform is lowered. The lifting device 2 refers to a device that can drive the fork frame 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 use other devices that can drive the fork frame 4 to expand or contract in the vertical direction.

[0052] The pressure detection component 7 is arranged on the fork frame 4, and is used to detect the pressure information of the fork frame 4; wherein, the pressure information of the fork frame 4 refers to the pressure that the fork frame 4 bears when it is folded, that is, the folding pressure or folding stress. The pressure detection component 7 can be arranged at the connection of the fork frame 4, such as hinges, pins and other positions, and can directly measure the pressure generated during the folding process. The pressure detection component 7 can also be arranged at some key stress points of the fork frame 4, such as the end of the support arm, the corner of the folding part, etc. These positions are also ideal positions where the pressure detection component 7 can be set, which can accurately reflect the stress conditions of the fork frame 4 during the folding process. The specific structure of the pressure detection component 7 is not specifically limited here, but is only illustrated by example. In some embodiments, the pressure detection component 7 includes a pressure sensor, so that the pressure information of the fork frame 4 can be easily detected.

[0053] like Figure 1 and Figure 3 As shown, the input end of the control module 6 is electrically connected to the pressure detection member 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 capable of driving the lifting device 2 to work. In some embodiments, the lifting device 2 includes a lifting motor, and the lifting drive device 3 is a motor driver. The motor driver can control the rotation speed and direction of the lifting motor by changing the parameters of the current or voltage input to the lifting motor, thereby controlling the lifting motor to drive the fork frame 4 to expand or contract in the vertical direction.

[0054] The control module 6 is used to: obtain pressure information, determine the position information of the fork frame 4, 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 4 meets the preset position rule. Among them, the control module 6 refers to a functional module capable of performing logical control. In some embodiments, the control module 6 includes a microprocessor. In other embodiments, other devices may also be used for control, such as one of PLC, DSP, and FPGA. No specific limitation is made here, only examples are given. The position information of the fork frame 4 refers to information reflecting the current retracted position of the fork frame 4. The standard storage position refers to the retracted position of the fork frame 4 when the fork frame 4 is fully retracted and not over-retracted. When the position information of the fork frame 4 reaches the standard storage position, it means that the fork frame 4 has been stored in place. The preset position rule refers to the situation where the position where the fork frame 4 stops retracting under the action of its own gravity is not satisfied by the standard storage position.

[0055] The lifting drive device 3 is electrically connected to the lifting device 2. The lifting drive device 3 is used to control the lifting device 2 to stop output based on the first control instruction so that the fork frame 4 remains in the current contracted state; wherein the first control instruction refers to the electrical signal used to control the lifting drive device 3, and the current contracted state refers to the contracted state of the fork frame 4 at this time. When the lifting device 2 stops outputting, the lifting device 2 will no longer move, and thus the fork frame 4 will no longer move, and will remain in the current contracted state and will no longer continue to contract. If the friction between the forks 4 is small, the forks 4 can be stored in place by their own gravity. By stopping the forks 4 from contracting further when the pressure information meets the preset pressure rules, it can prevent the forks 4 from contracting excessively and causing damage to the forks 4 due to excessive tension.

[0056] The lifting drive device 3 is also used to control the lifting device 2 to output negative torque based on the second control instruction, and control the lifting device 2 to stop outputting when the current negative torque reaches the preset negative torque and maintains the preset time, so that the fork frame 4 remains in the current contracted state. Wherein, the second control instruction refers to an electrical signal used to control the lifting drive device 3. When the lifting device 2 outputs negative torque, the fork frame 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 value that the negative torque output by the lifting device 2 is not greater than when the fork frame 4 is not over-contracted. The preset time is the time that the preset negative torque should be maintained. If the friction between the forks 4 is large, the fork frame 4 cannot be stored in place by its own gravity. By controlling the lifting device 2 to output negative torque when the position information of the fork frame 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 the preset time, the fork frame 4 can be stored in place while preventing the lifting device 2 from constantly pulling down the fork frame 4 to cause excessive pulling force.

[0057] In the above scheme, the control module 6 obtains pressure information and determines the position information of the fork frame 4. When the pressure information meets the preset pressure rule, the first control instruction is output, and when the position information of the fork frame 4 meets the preset position rule, the second control instruction is output; then the lifting drive device 3 controls the lifting device 2 to stop output based on the first control instruction, so that the fork frame 4 remains in the current retracted state; the lifting drive device 3 controls the lifting device 2 to output negative torque based on the second control instruction, and controls the lifting device 2 to stop output when the current negative torque reaches the preset negative torque and maintains the preset time, so that the fork frame 4 remains in the current retracted state. Therefore, when the friction between the forks 4 is large and the forks 4 cannot be stored in place by their own gravity, the lifting device 2 can output negative torque to pull down the fork frame 4 so that the fork frame 4 is stored in place, while preventing the lifting device 2 from continuously pulling down the fork frame 4 to cause excessive pulling force. When the friction between the forks 4 is small and the forks 4 can be stored in place by their own gravity, when the pressure information meets the preset pressure rules, the forks 4 can stop shrinking, so the forks 4 can be stored in place and prevented from shrinking too much and causing damage to the forks 4 due to excessive tension. Therefore, the problem that the forks 4 are difficult to shrink to the bottom while preventing deformation due to excessive shrinkage tension is solved. The life of the fork-type aerial work platform is increased, which is of great significance to the sustainable development and resource conservation of the industry.

[0058] In an optional embodiment of the present invention, Figure 1-Figure 3As shown, the control module 6 is specifically used to: output a first control instruction when the pressure information is greater than a preset pressure threshold. The preset pressure threshold refers to the value that the pressure information is greater than when the fork frame 4 is stored in place. When the pressure is too high, the fork frame 4 may be damaged. By outputting the first control instruction when the pressure information is greater than the preset pressure threshold, the fork frame 4 can stop shrinking when the pressure information is too high. Therefore, the fork frame 4 can be stored in place and can prevent the fork frame 4 from shrinking too much and causing the fork frame 4 to be damaged due to excessive tension.

[0059] In an optional embodiment of the present invention, the control module 6 is specifically used to: output a second control instruction when the distance between the position information and the standard storage position is less than a preset distance. The standard storage position refers to the value of the position information when the fork frame 4 is stored in place. When the distance between the position information and the standard storage position is less than the preset distance, it means that the fork frame 4 is close to being stored in place. If the friction between the fork frames 4 is large, the fork frame 4 cannot be stored in place by its own gravity. When the fork frame 4 is close to being stored in place, the lifting device 2 applies a negative torque to pull down the fork frame 4 so that the fork frame 4 continues to shrink until the negative torque increases to the preset negative torque and is maintained for a preset time, and the lifting device 2 is controlled to stop output, so that the fork frame 4 remains in the current contracted state, and the fork frame 4 is prevented from being pulled down continuously, so that the fork frame 4 is stored in place while preventing the lifting device 2 from pulling down the fork frame 4 continuously, resulting in excessive pulling force.

[0060] In an optional embodiment of the present invention, Figure 1-Figure 3 As shown, the lifting device 2 is used to feed back the lifting operation parameters to the control module 6 through the lifting drive device 3; the control module 6 is specifically used to: determine the maximum output torque based on the lifting operation parameters, and determine the preset negative torque based on the maximum output torque. Among them, the lifting operation parameters refer to the relevant parameters when the lifting device 2 is in operation. In some embodiments, the lifting device 2 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 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, when the preset time length is fixed, even if the preset negative torque is the same, the degree to which the lifting device 2 pulls down the fork frame 4 from the beginning of applying the negative torque to the end of output is different. When the preset time length is fixed and the maximum output torque of the lifting device 2 is the same, the value of the preset negative torque is different, and the degree to which the lifting device 2 pulls down the fork frame 4 from the beginning of applying the negative torque to the end of output is also different. Therefore, changes in the maximum output torque and the value of the preset negative torque will affect the degree to which the lifting device 2 pulls down the fork frame 4 from the beginning of applying the negative torque to the end of output. By determining the preset negative torque based on the maximum output torque, the degree to which the lifting device 2 pulls down the fork frame 4 when applying the negative torque can be better controlled, so that the lifting device 2 can better prevent the fork frame 4 from being damaged by excessive pulling force caused by the lifting device 2 constantly pulling down the fork frame 4 while the fork frame 4 is stored in place.

[0062] Based on the above embodiments, Figure 1-Figure 3 As 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 used 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 motor speed. Among them, the control module 6 is specifically used to: determine the motor power based on the motor current and motor voltage: P 功率 =U*I, I is the motor current, U is the motor voltage, P 功率 is the motor power; the maximum output torque is determined based on the motor power and 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 optional embodiment of the present invention, the control module 6 is specifically configured 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 The preset negative torque can be accurately calculated according to the maximum output torque through this formula, so as to better control the degree of pulling down the fork frame 4 when the lifting device 2 applies the negative torque, thereby better preventing the lifting device 2 from continuously pulling down the fork frame 4 and causing damage to the fork frame 4 due to excessive pulling force while the fork frame 4 is stored in place.

[0064] In an optional embodiment of the present invention, Figure 1-Figure 3As shown, the lifting device 2 includes a lifting motor; the control module 6 is specifically used to: obtain the total weight of the platform load, the lifting motor reduction ratio, the lead of the screw and the efficiency of the lifting motor, and determine the position information of the fork frame 4 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. Among them, the total weight of the platform load refers to the total weight of the fork frame 4, the platform body 1 and the load, and the lifting motor reduction ratio refers to the ratio between the speed of the input shaft (usually the motor shaft) and the speed of the output shaft (usually the load shaft). The lifting device 2 also includes a screw assembly, which includes a ball screw and a ball nut. The lead of the screw 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 determines the accuracy and efficiency of the lifting device 2. The larger the lead, the greater the displacement of the ball screw per rotation, so the lifting speed is faster. The efficiency of the lifting motor refers to the efficiency of the lifting motor in converting the input electrical energy into mechanical energy during the working process. The total weight of the platform load, the lifting motor reduction ratio, the lead of the screw, the efficiency of the lifting motor and the maximum output torque will jointly affect the position of the fork frame 4, so the position information of the fork frame 4 can be determined 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.

[0065] On the basis of the above embodiment, the position information includes the angle of the lifting motor when the fork frame 4 is retracted; wherein, the angle of the lifting motor refers to the angle of the lifting motor in the working stroke. When the fork frame 4 is retracted, the degree of retraction of the fork frame 4 is different, and the angle of the lifting motor will be different, so the angle of the lifting motor can reflect the position of the fork frame 4. The control module 6 is specifically used to: determine the angle of the lifting motor when the fork frame 4 is retracted 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 through the following mathematical relationship: F max =M 总 *9.8*2 / sinθ;F max =T max *η*2π*R / L; where M 总 is the total weight of the platform load, R is the motor reduction ratio, L is the lead of the screw, 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 frame 4 is retracted; F max By the above mathematical relationship, since other values ​​are known, the angle of the lifting motor when the fork frame 4 is retracted can be easily calculated to obtain accurate position information of the fork frame 4.

[0066] In an optional embodiment of the present invention, Figure 1-Figure 3As shown, the control module 6 is specifically used to: obtain the total weight of the platform load, and determine the preset pressure threshold based on the total weight of the platform load. The maximum pressure that the fork frame 4 can withstand is different under different total weights of the platform load. By determining the preset pressure threshold based on the total weight of the platform load, the preset pressure threshold can be more consistent with the actual situation of the fork frame 4, and the fork frame 4 can be better retracted to the bottom without excessive retraction force causing deformation.

[0067] Based on the above embodiment, the control module 6 is specifically used to: determine the preset pressure threshold value based on the total weight of the platform load by the following formula: 限制 =M 总 / 10, where M 总 is the total weight of the platform load, P 限制 is the preset pressure threshold. The above formula can be used to conveniently calculate the preset pressure threshold according to the total weight of the platform load, and the preset pressure threshold obtained is more accurate.

[0068] In an optional embodiment of the present invention, the fork-type aerial work platform further includes a power supply, which includes a battery, and the battery is electrically connected to the lifting drive device 3 for providing a DC working power supply.

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

[0070] Embodiment 2

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

[0072] S110, obtaining pressure information of the fork frame detected by the pressure detection component.

[0073] Among them, the pressure information of the fork frame refers to the pressure that the fork frame bears when it is folded, that is, the folding pressure or folding stress. The pressure detection component can be set at the connection of the fork frame, such as hinges, pins and other positions, and can directly measure the pressure generated during the folding process. The pressure detection component can also be set at some key stress points of the fork frame, such as the end of the support arm, the corner of the folding part, etc. These positions are also ideal positions where the pressure detection component can be set, which can accurately reflect the stress conditions of the fork frame during the folding process. The specific structure of the pressure detection component is not specifically limited here, but is only illustrated by example. In some embodiments, the pressure detection component includes a pressure sensor, so that the pressure information of the fork frame can be easily detected.

[0074] S120: 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 remains in the current retracted state.

[0075] The first control instruction refers to an electrical signal for controlling the lifting drive device, and the current contraction state refers to the contraction state of the fork frame at this time. When the lifting device stops outputting, the lifting device will no longer move, and the fork frame will no longer move, and will remain in the current contraction state and will no longer continue to contract. If the friction between the forks is small, the forks can be stored in place by their own gravity. When the pressure information meets the preset pressure rules, the forks are stopped from contracting further, which can prevent the forks from being damaged due to excessive tension caused by excessive contraction of the forks.

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

[0077] The fork position information refers to information reflecting the current retracted position of the fork.

[0078] S140. When the position information of the fork frame satisfies a 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 a 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.

[0079] The preset position rule refers to the situation that the position where the fork frame stops shrinking due to its own weight is not satisfied by 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 negative torque, the fork frame will continue to shrink under the action of the negative torque. The current negative torque refers to the negative torque currently output by the lifting device. The preset negative torque refers to the value that the negative torque output by the lifting device is not greater than when the fork frame is not over-shrunk. The preset duration is the duration that the preset negative torque should be maintained. If the friction between the forks is large, the fork frame cannot be stored in place by its own weight. When the position information of the fork frame meets the preset position rule, the lifting device is controlled to output negative torque, and when the current negative torque reaches the preset negative torque and is maintained for the preset duration, the lifting device is controlled to stop outputting. This can prevent the lifting device from constantly pulling down the fork frame and causing excessive pulling force while the fork frame is stored in place.

[0080] The above scheme obtains the pressure information of the fork frame detected by the pressure detection component, and when the pressure information meets the preset pressure rule, outputs the 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 frame remains in the current retracted state. When the friction between the forks is small and the fork frame can be stored in place by its own gravity, when the pressure information meets the preset pressure rule, the fork frame can stop retracting, so that the fork frame can be stored in place and can prevent the fork frame from being damaged by excessive tension due to excessive contraction. By determining the position information of the fork frame, when the position information of the fork frame meets the preset position rule, outputs the 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 is maintained for a preset time, the lifting drive device controls the lifting device to stop output, so that the fork frame remains in the current retracted state. Therefore, when the friction between the forks is large and the forks cannot be stored in place by their own gravity, the lifting device can output negative torque to pull down the forks so that the forks are stored in place, while preventing the lifting device from continuously pulling down the forks to cause excessive tension. Therefore, the problem that the forks are difficult to shrink to the bottom while preventing deformation caused by excessive shrinkage tension is solved. The service life of the fork-type aerial work platform is increased, which is of great significance to the sustainable development and resource conservation of the industry.

[0081] Embodiment 3

[0082] Embodiment 3 of the present invention provides a control method for a fork-type aerial work platform. This embodiment improves on Embodiment 2. Optionally, when the pressure information meets 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 meets 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, Figure 5 As shown, the control method of the fork-type aerial work platform includes:

[0083] S210: Obtain pressure information of the fork frame detected by the pressure detection component.

[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 frame remains in the current retracted state.

[0085] The preset pressure threshold refers to the value that the pressure information is greater than when the fork frame is stored in place. When the pressure is too high, the fork frame may be damaged. By outputting the first control instruction when the pressure information is greater than the preset pressure threshold, the fork frame can be stopped from retracting when the pressure information is too high. Therefore, the fork frame can be stored in place and excessive contraction of the fork frame can be prevented, which may cause damage to the fork frame due to excessive tension.

[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, 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 a 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.

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

[0089] In an optional embodiment of the present invention, when the distance between the position information and the standard storage position is less than a preset distance, before outputting the second control instruction, it also 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. Among them, the lifting operation parameters refer to the relevant parameters when the lifting device is in operation. 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 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 torque of the lifting device is different, when the preset time length is fixed, even if the preset negative torque is the same, the degree to which the lifting device pulls down the fork frame from the beginning of applying the negative torque to the end of output is different. When the preset time length is fixed and the maximum output torque of the lifting device is the same, the values ​​of the preset negative torque are different, and the degree to which the lifting device pulls down the fork frame from the beginning of applying the negative torque to the end of output is also different. Therefore, changes in the values ​​of the maximum output torque and the preset negative torque will affect the degree to which the lifting device pulls down the fork frame from the beginning of applying the negative torque to the end of output. By determining the preset negative torque based on the maximum output torque, the degree to which the lifting device pulls down the fork frame when applying the negative torque can be better controlled, thereby better preventing the lifting device from constantly pulling down the fork frame while the fork frame is stored in place, resulting in excessive tension and damage to the fork frame.

[0091] In an optional 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] Wherein, the control module is specifically used to determine the motor power based on the motor current and the motor voltage: 功率 =U*I, I is the motor current, U is the motor voltage, P 功率 The maximum output torque is determined based on the motor power and the motor speed through the following mathematical relationship: P 功率 =T max *n 转速 / 9549, among which, T max is the maximum output torque, n 转速 is the motor speed.

[0093] In an optional 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 by the following formula: 反 =T max / 5, T max is the maximum output torque, T 反 The preset negative torque is the preset negative torque. The preset negative torque can be accurately calculated according to the maximum output torque through this formula, so as to better control the degree of pulling down the fork frame when the lifting device applies the negative torque, thereby better preventing the lifting device from constantly pulling down the fork frame and causing excessive tension to damage the fork frame while the fork frame is stored in place.

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

[0095] Among them, the total weight of the platform load refers to the total weight of the fork frame, the platform body and the load, and the lifting motor reduction ratio refers to the ratio between the speed of the input shaft (usually the motor shaft) and the speed of the output shaft (usually the load shaft). The lifting device also includes a screw assembly, which includes a ball screw and a ball nut. The screw lead refers to the stroke when the ball nut rotates 2π radians relative to the ball screw. In the lifting device, the size of the screw lead determines the accuracy and efficiency of the lifting device. The larger the lead, the greater the displacement of the ball screw per rotation, so the lifting speed is faster. The lifting motor efficiency refers to the efficiency of the lifting motor in converting the input electrical energy into mechanical energy during operation. The total weight of the platform load, the lifting motor reduction ratio, the screw lead, the lifting motor efficiency and the maximum output torque will jointly affect the position of the fork frame, so the position information of the fork frame can be determined according to the total weight of the platform load, the motor reduction ratio, the screw lead, the lifting motor efficiency 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 is retracted; wherein, the angle of the lifting motor refers to the angle of the lifting motor in the working stroke, and when the fork frame is retracted, the degree of retraction of the fork frame is different, and the angle of the lifting motor will be different, so the angle of the lifting motor can reflect the position of the fork frame.

[0097] The determining of 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 includes: determining the angle of the lifting motor when the fork frame is retracted through the following mathematical relationship 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: F max =M 总 *9.8*2 / sinθ;F max =T max *η*2π*R / L; where M 总 is the total weight of the platform load, R is the motor reduction ratio, L is the lead of the screw, 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 frame is retracted; F max By using the above mathematical relationship, since other values ​​are known, the angle of the lifting motor when the fork frame is retracted can be easily calculated to obtain accurate fork frame position information.

[0098] In an optional embodiment of the present invention, when the pressure information satisfies the preset pressure rule, before outputting the first control instruction, it further includes: obtaining the total weight of the platform load, and determining the preset pressure threshold based on the total weight of the platform load. Wherein, under different total weights of the platform load, the maximum pressure that the fork frame can withstand is also different. By determining the preset pressure threshold based on the total weight of the platform load, the preset pressure threshold can be more in line with the actual situation of the fork frame, and the fork frame can be better retracted to the bottom without excessive retraction force causing deformation.

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

[0100] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0101] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in 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.

2. The fork-type aerial work platform according to claim 1, characterized in that: The lifting device includes a lifting motor; The control module is specifically used to obtain the total weight of the platform load, the lifting motor reduction ratio, 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.

3. The fork-type aerial work platform according to claim 2, characterized in that: The position information includes the angle of the lifting motor when the fork frame is retracted.

4. The fork-type aerial work platform according to any one of claims 1 to 3, 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.

5. 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 4, 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.

6. The control method of the fork-type aerial work platform according to claim 5, 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.

7. The control method of a fork-type aerial work platform according to claim 5, 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.

8. The control method of a fork-type aerial work platform according to claim 5, 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.

9. The control method of a fork-type aerial work platform according to claim 6, 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.

10. The control method of a fork-type aerial work platform according to claim 9, 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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