Double-scissor-fork type lifting operation device and system

Abstract

The invention relates to a double-shear-fork type lifting operation device and system, and belongs to the technical field of lifting platforms. The device comprises an upper base, a lower base, a first pair of sliding grooves and a second pair of sliding grooves; the lower base is arranged opposite to the upper base and is fixedly provided with a second pair of sliding grooves; the scissor fork mechanism comprises a first scissor fork mechanism body and a second scissor fork mechanism body, the first scissor fork mechanism body and the second scissor fork mechanism body are hinged through a pin shaft, and the front end of the bottom of the first scissor fork mechanism body and the front end of the bottom of the second scissor fork mechanism body are slidably connected with the second pair of sliding grooves through pin shafts; the rear end of the bottom of the first shear fork mechanism and the front end of the bottom of the second shear fork mechanism are fixedly connected with the second pair of sliding grooves. The front end of the upper portion of the first shear fork mechanism and the front end of the upper portion of the second shear fork mechanism are both in sliding connection with the first pair of sliding grooves through pin shafts, and the rear end of the upper portion of the first shear fork mechanism and the front end of the upper portion of the second shear fork mechanism are both fixedly connected with the first pair of sliding grooves. The bearing capacity of the operation device is improved, and lifting potential safety hazards are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of lifting platforms, and particularly relates to a double scissor-type lifting operation device and system. Background Art

[0002] The scissor-type lifting platform is a vertical lifting device widely used in aerial work. It is composed of multiple scissor-type structures connected together, making the lifting of the platform relatively stable and having a high work safety guarantee. It can be widely used for equipment maintenance, mechanical installation, equipment maintenance, and building maintenance both indoors and outdoors in stations, docks, bridges, halls, and factories.

[0003] In the patent with the patent number 202210933072.6: A double scissor aerial work platform facilitating operation adjustment, this solution uses two groups of single scissors to lift the platform. The operation platform includes a bottom plate and a top plate. Four chutes are respectively opened at the upper end of the bottom plate and the lower end of the top plate. Four sliding plates are respectively slidably connected to the inner walls of the four chutes. Two scissor-type steel frames are installed between the two corresponding sliding plates, the upper end of the bottom plate, and the lower end of the top plate. The rotating parts on the side walls of the two scissor-type steel frames are jointly connected to a rotating shaft.

[0004] Although this device can also lift the platform through single scissors, this solution still has certain defects: 1) Due to the use of single scissors, the bearing capacity is limited; 2) Although a pair of single scissors are provided, the two single scissors are arranged in a line. If operators perform aerial work on this platform, it may cause tipping. Summary of the Invention

[0005] In view of this, it is necessary to provide a double scissor-type lifting operation device and system to solve the problems of poor bearing capacity and instability of the double scissor aerial work platform.

[0006] To solve the above problems, in the first aspect, the present invention provides a double scissor-type lifting operation device, including: An upper base, fixedly provided with a first pair of chutes; A lower base, oppositely arranged with the upper base and fixedly provided with a second pair of chutes; A scissor mechanism, including a first scissor mechanism and a second scissor mechanism arranged oppositely. The first scissor mechanism and the second scissor mechanism are hinged to each other through a pin shaft. The front end of the bottom of the first scissor mechanism and the front end of the bottom of the second scissor mechanism are both slidably connected to the second pair of chutes through a pin shaft. The rear end of the bottom of the first scissor mechanism and the front end of the bottom of the second scissor mechanism are both fixedly connected to the second pair of chutes; the front end of the upper part of the first scissor mechanism and the front end of the upper part of the second scissor mechanism are both slidably connected to the first pair of chutes through a pin shaft. The rear end of the upper part of the first scissor mechanism and the front end of the upper part of the second scissor mechanism are both fixedly connected to the first pair of chutes.

[0007] In a possible implementation, the pin shaft connecting the front end of the bottom of the first scissor mechanism and the front end of the bottom of the second scissor mechanism is the bottom pin shaft. Both ends of the bottom pin shaft are hinged to the first slider, and the first slider is slidably connected to the second pair of sliding grooves.

[0008] In a possible implementation, the pin shaft connecting the upper front end of the first scissor mechanism and the upper front end of the second scissor mechanism is the upper pin shaft. Both ends of the upper pin shaft are hinged to the second slider, and the second slider is slidably connected to the first pair of sliding grooves.

[0009] In a possible implementation, it further includes a hydraulic cylinder. A connecting plate is fixedly arranged on the scissor mechanism. Both ends of the hydraulic cylinder are hinged to the pin shaft sleeve, the pin shaft sleeve is slidably connected to the pin shaft, and the pin shaft is hinged to the connecting plate.

[0010] In a possible implementation, the hydraulic cylinders are evenly distributed on the scissor mechanism.

[0011] In a possible implementation, a main platform is further arranged on the upper surface of the upper base. The main platform is connected to the upper base through a rotating device, and the left telescopic platform and the right telescopic platform are connected to both sides of the main platform through chains. In a second aspect, the present invention further provides a double-scissor type lifting operation system, including: It includes the double-scissor type lifting operation device described in any one of the above, and further includes a displacement monitoring component, a PLC controller, a switch component, and a power component; The displacement monitoring component is used to detect the displacement of the hydraulic cylinder; The PLC controller is connected to the displacement monitoring component and is used to generate a first control instruction according to the error value of the displacement; The switch component is used to switch its own state from the initial state to the first state or from the initial state to the second state according to the first control instruction, and simultaneously generate a second control instruction. The first state is to make the hydraulic oil enter the hydraulic cylinder, and the second state is to make the hydraulic oil flow out of the hydraulic cylinder; The power component is connected to the switch component and is used to receive the second control instruction to start the motor of the power component.

[0012] In a possible implementation, the power component includes: a motor and an oil tank; The oil tank is connected to the switch component and is used to store hydraulic oil; The motor is connected to the oil tank and is used to drive the inflow or outflow of the hydraulic oil in the oil tank.

[0013] In a possible implementation, the switch component is a four-way three-position proportional reversing valve.

[0014] In a possible implementation, the PLC controller is configured to obtain the displacement deviation and displacement error of the hydraulic cylinder, where the displacement deviation is obtained based on the input quantity and displacement change amount corresponding to the system adjustment channel, and the displacement error is obtained based on the input quantity and displacement change amount corresponding to the system free channel; obtain a synchronization error based on the displacement deviation and the displacement error; obtain the proportional gain parameter increment and integral gain parameter increment of the system adjustment channel based on the displacement deviation and the synchronization error; determine a fuzzy rule based on the displacement deviation, displacement error, synchronization error, proportional gain parameter increment, and integral gain parameter increment; adjust the gain parameter of the system adjustment channel based on the fuzzy rule to obtain an adjusted gain parameter; adjust the flow rate and pressure of the hydraulic cylinder based on the adjusted gain parameter; control the synchronous lifting of the double scissor lift work platform based on the flow rate and pressure of the hydraulic cylinder.

[0015] The beneficial effects of the present invention are as follows: The double scissor lift working device provided in this embodiment includes an upper base fixedly provided with a first pair of sliding grooves; a lower base disposed opposite to the upper base and fixedly provided with a second pair of sliding grooves. The upper and lower bases are disposed opposite to each other, so as to ensure that the device is evenly stressed in the vertical direction during the ascending or descending process. The scissor mechanism includes a first scissor mechanism and a second scissor mechanism disposed opposite to each other. The first scissor mechanism and the second scissor mechanism are hinged by a pin shaft. The front end of the bottom of the first scissor mechanism and the front end of the bottom of the second scissor mechanism are both slidably connected to the second pair of sliding grooves by a pin shaft. The rear end of the bottom of the first scissor mechanism and the front end of the bottom of the second scissor mechanism are both fixedly connected to the second pair of sliding grooves; the front end of the upper part of the first scissor mechanism and the front end of the upper part of the second scissor mechanism are both slidably connected to the first pair of sliding grooves by a pin shaft. The rear end of the upper part of the first scissor mechanism and the front end of the upper part of the second scissor mechanism are both fixedly connected to the first pair of sliding grooves. Sliding grooves are respectively provided at the bottom and the upper part of the scissor mechanism, so that the scissor mechanism can be synchronously contracted when being pushed or pulled by the hydraulic cylinder, thereby maintaining the stability of the device. The scissor device of the working platform of the invention includes two scissor mechanisms disposed opposite to each other. The two scissor mechanisms are superimposed to improve the load-bearing capacity of the platform, and each scissor mechanism corresponds to a pair of sliding grooves up and down. When being pushed or pulled by the hydraulic cylinder, the force can be quickly dispersed and conducted to the sliding grooves and slide in the sliding grooves, improving the stability of the working state and reducing the safety hazard of lifting. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic structural diagram of an embodiment of a double scissor lift work platform provided by the present invention; Figure 2Lifting structure diagram of an embodiment of a double scissor - type lifting work platform provided by the present invention; Figure 3 Schematic diagram of the installation of hydraulic cylinders in an embodiment of a double scissor - type lifting work platform provided by the present invention; Figure 4 Schematic diagram of the structure of a lifting control circuit in an embodiment of a double scissor - type lifting work system provided by the present invention; Figure 5 Schematic diagram of cross - coupled fuzzy PID synchronous control principle in an embodiment of a double scissor - type lifting work system provided by the present invention; Figure 6 Diagram for selecting the grade membership function of displacement deviation in PID synchronization in an embodiment of a double scissor - type lifting work system provided by the present invention; Figure 7 Diagram for selecting the grade membership function of the increment of the first proportional gain parameter in PID synchronization in an embodiment of a double scissor - type lifting work system provided by the present invention; Figure 8 Diagram for selecting the grade membership function of the increment of the first integral gain parameter in PID synchronization in an embodiment of a double scissor - type lifting work system provided by the present invention; Wherein: 1 - upper base; 2 - lower base; 3 - second pair of sliding grooves; 4 - scissor mechanism; 5 - pin shaft; 6, first slider; 7 - scissor unit; 8 - connecting plate; 9 - lower hydraulic cylinder; 10 - upper hydraulic cylinder; 11 - pin shaft sleeve; 12 - main platform; 13 - rotating device; 14 - chain; 15 - left telescopic platform; 16 - right telescopic platform; 17 - fuel tank; 18 - filter; 19 - motor; 20 - gear pump; 21 - overflow valve; 22 - throttle valve; 23 - four - position three - way proportional reversing valve; 24 - accumulator; 25 - balance valve; 26 - hydraulic cylinder; 27 - displacement sensor; 28 - amplifier; 29 - PLC controller; 30 - industrial remote controller. Detailed implementation manners

[0017] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present invention.

[0018] In the description of the embodiments of the present invention, unless otherwise specified, the meaning of "a plurality of" is two or more. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships, for example: A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone.

[0019] In the embodiments of the present invention, the descriptions such as "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Therefore, the technical features defined with "first" and "second" may explicitly or implicitly include at least one such feature.

[0020] Referring to "embodiments" herein means that the specific features, structures, or characteristics described in connection with the embodiments may be included in at least one embodiment of the present invention. The phrase appears in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0021] Before presenting the embodiments, the following terms are explained first.

[0022] A hydraulic cylinder is a hydraulic actuator that converts hydraulic energy into mechanical energy and performs linear reciprocating motion (or swinging motion). It has a simple structure and reliable operation. When used to achieve reciprocating motion, it can eliminate the deceleration device, and there is no transmission gap, and the motion is stable. Therefore, it is widely used in the hydraulic systems of various machines. The output force of the hydraulic cylinder is proportional to the effective area of the piston and the pressure difference on both sides; the hydraulic cylinder basically consists of a cylinder barrel and a cylinder head, a piston and a piston rod, a sealing device, a buffering device, and an exhaust device.

[0023] The present invention provides a double scissor - type lifting operation device and system, which are described separately below.

[0024] Figure 1 It is a schematic flow diagram of an embodiment of the double scissor - type lifting platform provided by the present invention, as Figure 1As shown in the figure, a double scissor lift working device includes: an upper base 1, which is fixedly provided with a first pair of chutes; a lower base 2, which is arranged opposite to the upper base and is fixedly provided with a second pair of chutes 3; a scissor mechanism 4, which includes a first scissor mechanism and a second scissor mechanism arranged opposite to each other. The first scissor mechanism and the second scissor mechanism are hinged to each other through a pin shaft 5. The front end of the bottom of the first scissor mechanism and the front end of the bottom of the second scissor mechanism are both slidably connected to the second pair of chutes 3 through a pin shaft, and the rear end of the bottom of the first scissor mechanism and the front end of the bottom of the second scissor mechanism are both fixedly connected to the second pair of chutes 3; the front end of the upper part of the first scissor mechanism and the front end of the upper part of the second scissor mechanism are both slidably connected to the first pair of chutes through a pin shaft, and the rear end of the upper part of the first scissor mechanism and the front end of the upper part of the second scissor mechanism are both fixedly connected to the first pair of chutes.

[0025] In summary, the double scissor lift working device provided in this embodiment includes an upper base, which is fixedly provided with a first pair of chutes; a lower base, which is arranged opposite to the upper base and is fixedly provided with a second pair of chutes. The upper and lower bases are arranged opposite to each other, so as to ensure that the device is uniformly stressed in the vertical direction during the ascending or descending process. The scissor mechanism includes a first scissor mechanism and a second scissor mechanism arranged opposite to each other. The first scissor mechanism and the second scissor mechanism are hinged to each other through a pin shaft. The front end of the bottom of the first scissor mechanism and the front end of the bottom of the second scissor mechanism are both slidably connected to the second pair of chutes through a pin shaft, and the rear end of the bottom of the first scissor mechanism and the front end of the bottom of the second scissor mechanism are both fixedly connected to the second pair of chutes; the front end of the upper part of the first scissor mechanism and the front end of the upper part of the second scissor mechanism are both slidably connected to the first pair of chutes through a pin shaft, and the rear end of the upper part of the first scissor mechanism and the front end of the upper part of the second scissor mechanism are both fixedly connected to the first pair of chutes. Chutes are respectively arranged at the bottom and the upper part of the scissor mechanism, so that the scissor mechanism can be synchronously contracted when receiving the thrust or pulling force of the hydraulic cylinder, thereby maintaining the stability of the device. The scissor device of the working platform of the invention includes two scissor mechanisms arranged opposite to each other. The two scissor mechanisms are superimposed to improve the load-bearing capacity of the platform, and a pair of chutes are correspondingly arranged above and below each scissor mechanism. When receiving the thrust or pulling force of the hydraulic cylinder, the force can be quickly dispersed and conducted to the chutes and slide in the chutes, improving the stability of the working state and reducing the safety hazards of lifting.

[0026] In some embodiments of the present invention, the pin shaft 5 connecting the front end of the bottom of the first scissor mechanism and the front end of the bottom of the second scissor mechanism is a bottom pin shaft. Both ends of the bottom pin shaft are hinged to a first slider 6, and the first slider 6 is slidably connected to the second pair of chutes.

[0027] In some embodiments of the present invention, the pin shaft connecting the front end of the upper part of the first scissor mechanism and the front end of the upper part of the second scissor mechanism is an upper pin shaft. Both ends of the upper pin shaft are hinged to a second slider, and the second slider is slidably connected to the first pair of chutes.

[0028] In a specific embodiment of the present invention, the structures of the first scissor mechanism and the second scissor mechanism are the same. The specific structure of the first scissor mechanism is described in detail below, and the structure of the second scissor mechanism is the same by analogy. As Figure 2 shown, the first scissor mechanism includes six layers of inner and outer scissor units 7. Each scissor unit 7 includes two scissor arms 8 that are cross - arranged and hinged together by a pin shaft. Adjacent two - layer scissor units are arranged one above the other. The top end of the lower - layer scissor arm is hinged to the bottom end of the upper - layer scissor arm by a pin shaft. The pin shaft at the top layer is hinged to the second slider, and the second slider can slide in the first pair of chutes. The pin shaft at the bottom layer is hinged to the first slider 6, and the first slider 6 can slide in the second pair of chutes.

[0029] In some embodiments of the present invention, a hydraulic cylinder is further included. A connecting plate 9 is fixedly arranged on the scissor mechanism 4. Both ends of the hydraulic cylinder are hinged to a pin bushing. The pin bushing is slidably connected to a pin shaft, and the pin shaft is hinged to the connecting plate. The hydraulic cylinder is used to drive the scissor mechanism to rise and fall.

[0030] In some embodiments of the present invention, the hydraulic cylinders are evenly distributed on the scissor mechanism 4 to ensure the stability of rising and falling.

[0031] In a specific embodiment of the present invention, as Figure 3 shown, two hydraulic cylinders are arranged on the scissor mechanism 4. For example, upper hydraulic cylinders 10 are obliquely arranged on the first layer and the third layer of the first scissor mechanism and the second scissor structure with six layers respectively, and lower hydraulic cylinders 9 are obliquely arranged on the fourth layer and the sixth layer of the first scissor mechanism and the second scissor structure. The bottom of the lower hydraulic cylinder 9 is hinged to a pin bushing 11. The pin bushing 11 is slidably connected to a pin shaft. The connecting plate 8 is fixedly connected to the two inner scissor arms of the scissor unit 7, and the pin shaft is connected to the two connecting plates 8. When the four hydraulic cylinders are arranged side - by - side horizontally, the horizontal space occupancy rate is high and the lifting height is limited. At the same time, when the hydraulic cylinders are concentrated on the same plane, a weak - stiffness area is formed in the middle of the scissor mechanism; arranging them up and down on the left and right sides can optimize and release the horizontal space, greatly increase the lifting height, and improve the stiffness of the mechanism.

[0032] In some embodiments of the present invention, a main platform 12 is further arranged on the upper surface of the upper base 1. The main platform 12 is connected to the upper base 1 through a rotating device 13. The two sides of the main platform are connected to the left telescopic platform 15 and the right telescopic platform 16 through chains 14, which can realize the ±90° rotation of the platform. The left telescopic platform 15 and the right telescopic platform 16 can realize a free telescopic length of 1.5 m.

[0033] Workflow of this embodiment: When the platform ascends, the lower hydraulic cylinder 9 and the upper hydraulic cylinder 10 extend, synchronously driving the scissor mechanism, so that the distance between the parallel scissor arms increases, the slider moves towards the middle position of the chute, the opening distance of the scissor component becomes smaller, and the amplitude change heights of each scissor unit are superposed synchronously, driving the main platform 12 to move upward; when the platform descends, the lower hydraulic cylinder 9 and the upper hydraulic cylinder 10 retract, synchronously driving the scissor mechanism, so that the distance between the parallel scissor arms decreases, the slider moves towards the outer end position of the chute, the opening distance of the scissor double arms becomes larger, and the amplitude change heights of each scissor unit decrease synchronously, driving the main platform 12 to move downward.

[0034] When the platform descends, the lower hydraulic cylinder 9 and the upper hydraulic cylinder 10 shorten, synchronously driving the scissor component, so that the distance between the parallel scissor arms increases, the slider moves towards the middle position of the chute, the opening distance of the scissor component becomes smaller, and the amplitude change heights of each scissor unit are superposed synchronously, driving the main platform 12 to move upward; when the platform descends, the lower hydraulic cylinder 9 and the upper hydraulic cylinder 10 retract, synchronously driving the scissor component, so that the distance between the parallel scissor arms decreases, the slider moves towards the outer end position of the chute, the opening distance of the scissor component becomes larger, and the amplitude change heights of each scissor component decrease synchronously, driving the main platform 12 to move downward.

[0035] In a second aspect, the present invention also provides a double-scissor type lifting operation system, including the double-scissor type lifting operation platform described in any one of the above, including the double-scissor type lifting operation platform described in any one of the above, and further including a displacement monitoring component, a PLC controller, a switch component, and a power component; The displacement monitoring component is used to detect the displacement of the hydraulic cylinder; The PLC controller is connected to the displacement monitoring component and is used to generate a first control instruction according to the error value of the displacement; The switch component is used to switch its own state from the initial state to the first state or from the initial state to the second state according to the first control instruction, and at the same time generate a second control instruction. The first state is to make the hydraulic oil enter the hydraulic cylinder, and the second state is to make the hydraulic oil flow out of the hydraulic cylinder; The power component is connected to the switch component and is used to receive the second control instruction to start the motor of the power component.

[0036] In some embodiments of the present invention, the power component includes: a motor and a fuel tank; The fuel tank is connected to the switch component and is used to store hydraulic oil; The motor is connected to the fuel tank and is used to drive the inflow or outflow of the hydraulic oil in the fuel tank.

[0037] In some embodiments of the present invention, the switch component is a four-way three-position proportional reversing valve.

[0038] In a specific embodiment of the present invention, the displacement monitoring component is a displacement sensor for detecting the displacement of the hydraulic cylinder.

[0039] In a specific embodiment of the present invention, as Figure 4 shown, the displacement sensor 27 is located inside the hydraulic cylinder 26 and is connected to the amplifier 28, transmitting the detected displacement errors of the four hydraulic cylinders to the amplifier 28; the industrial remote controller 30, the PLC controller 29, the proportional amplifier 28 and the four-way three-position proportional directional control valve 23 are connected in sequence to achieve the commutation function of the proportional directional control valve and realize the lifting and stopping of the working platform.

[0040] In a specific embodiment of the present invention, the system further includes: an amplifier 28, an industrial remote controller 28, a filter 18, a gear pump 20, a relief valve 21, a throttle valve 22, an accumulator 24 and a balance valve 25.

[0041] The above components are used to construct a hydraulic synchronous control circuit. The connection relationship of the hydraulic synchronous control circuit is as follows: the motor 19, the displacement sensor 27 and the PLC controller 29 are connected. The displacement sensor 27 is arranged inside the hydraulic cylinder 26, and the displacement sensor 27 is connected to the PLC controller 29.

[0042] The displacement sensor 27 is connected to the amplifier 28, the amplifier 28 is connected to the PLC controller 29, the hydraulic cylinder 26 is connected to the gear pump 20, the gear pump 20 is connected to the motor, and the gear pump 20 is connected to the oil tank 17. An accumulator 24 is provided in the hydraulic synchronous control circuit to maintain pressure and replenish oil for the system when the platform stops at any position; a throttle valve 22 is provided to control the lifting speed of the hydraulic cylinder. A balance valve 25 is arranged between the proportional directional control valve 23 and the hydraulic cylinder 26 to achieve the balance control of the hydraulic cylinder 26 and the main platform 7.

[0043] In a specific embodiment of the present invention, the working process of the lifting control circuit in the rising stage is as follows: the industrial remote controller 30 sends a rising instruction to the PLC controller 29, the PLC controller 29 sends a signal for the working platform to rise, which reaches the proportional directional control valve 23 through the amplifier 28. The left position of the proportional directional control valve 23 is connected, the motor 19 starts, and the hydraulic oil flows out from the oil tank 17, passes through the gear pump 20, the throttle valve 22, the proportional directional control valve 23, and the balance valve 25 and enters the rodless cavity of the hydraulic cylinder 26, pushing the working platform to rise, and the hydraulic system charges the accumulator 24.

[0044] The working process of the lifting control circuit in the ascending stage is as follows: The industrial remote controller 30 sends a descending instruction to the PLC controller 29. The PLC controller 29 sends a signal for the work platform to descend. After passing through the amplifier 28, it reaches the proportional directional valve 23. The right position of the proportional directional valve 23 is connected. The motor 19 starts. The hydraulic oil flows out from the oil tank 17, passes through the gear pump 20, throttle valve 22, proportional directional valve 23, and balance valve 25, and enters the rod chamber of the hydraulic cylinder 26, pushing the work platform to descend. The hydraulic system charges the accumulator.

[0045] In summary, in the embodiment of the present invention, the lifting and descending of the hydraulic cylinder are controlled through the lifting control circuit. Therefore, through the lifting and descending of the hydraulic cylinder, the ascending and descending of the scissor sub-arms can be driven. The ascending and descending of the scissor sub-arms further drive the ascending and descending of the scissor mechanism. The ascending and descending of the scissor mechanism further drive the ascending and descending of the scissor device. The ascending and descending of the scissor device further drive the ascending and descending of the upper base, thereby realizing the ascending and descending of the work platform.

[0046] In some embodiments of the present invention, the PLC controller is used to, obtain the displacement deviation and displacement error of the hydraulic cylinder. The displacement deviation is obtained based on the input quantity and displacement change amount corresponding to the system adjustment channel. The displacement error is obtained based on the input quantity and displacement change amount corresponding to the system free channel; obtain the synchronization error based on the displacement deviation and the displacement error; obtain the proportional gain parameter increment and integral gain parameter increment of the system adjustment channel based on the displacement deviation and the synchronization error; determine the fuzzy rules based on the displacement deviation, displacement error, synchronization error, proportional gain parameter increment, and integral gain parameter increment. The proportional gain parameter increment is the first proportional gain parameter increment, that is, Figure 5 the proportional gain parameter increment of the medium scenic spot PID controller 1. The integral gain parameter increment is the first integral gain parameter increment, that is, Figure 5 the integral gain parameter increment of the medium scenic spot PID controller 1; adjust the gain parameters of the system adjustment channel based on the fuzzy rules to obtain the adjusted gain parameters; adjust the flow rate and pressure of the hydraulic cylinder based on the adjusted gain parameters; control the synchronous lifting and descending of the double-scissor type lifting work platform based on the flow rate and pressure of the hydraulic cylinder.

[0047] In a specific embodiment of the present invention, cross-coupling control and fuzzy PID control are used for the synchronous control of a double scissor lift platform with a four-cylinder symmetric arrangement to ensure that the four hydraulic cylinders achieve synchronous movement during the lifting process to maintain the horizontal state of the platform. Due to the symmetric structure, the cross-coupling fuzzy PID synchronous control method for the double cylinders will be introduced below, and the control principle is as shown in Figure 5 as follows. The following are the detailed implementation steps: This control method divides the two channels of the two valve-controlled cylinder systems into an adjustment channel and a free channel. Figure 5 In r ( t ) is the system command input quantity; u 1 ( t ) and u 2 ( t ) are the control output quantities of the channel PID controllers; y 1 ( t ) and y 2 ( t ) are the position output quantities of the two-channel valve-controlled cylinder systems; e 1 ( t ) and e 2 ( t ) are the respective tracking errors of the two-channel valve-controlled cylinder systems, e 1 ( t ) = r ( t ) - y 1 ( t ), e 2 ( t ) = r ( t ) - y 2 ( t ); e 12 ( t ) is the synchronous error between the two-channel valve-controlled cylinder systems, e 12 ( t ) = y 1 ( t ) - y 2 ( t ). This control strategy adds the PID control parameters in the adjustment channel on the basis of the original classical PID synchronous control algorithmK P1 and K I1 fuzzy adjustment module. The fuzzy control module uses e 1 ( t ) and e 2 ( t ) as input variables, and a two-input two-output fuzzy decision-making system with △ K P1 and △ K I1 as output variables. The specific synchronization control principle is: At the beginning, both the adjustment channel and the free channel use the command input amount r ( t ) as the tracking target; when e 12 ( t ) ≠ 0 but is not large, on the one hand, both the adjustment channel and the free channel use the command input amount r ( t ) as the tracking target, on the other hand, the adjustment channel will also adjust △ e 12 ( t ) in real time to make K P1 and △ K I1 such that e 12 ( t ) → 0; when e 12 ( t ) is very large, u 1 ( t ) and u 2 ( t ) can be directly cut off, and even the hydraulic pump can be stopped to prevent system failures.

[0048] The control method of the specific cross-coupled fuzzy PID synchronization controller for double cylinders is as follows: Step 1: Selection of fuzzy variables Select the displacement deviation of the adjustment channel e 1 ( t ) and the displacement error between channels e 2 ( t ) as fuzzy control input variables, and select the fuzzy output control quantity as the PID control parameters △ K P1 and △ K I1, in this two-input two-output fuzzy controller, △ K P and △ K I can be expressed as △ K P = [△ K Pmin , △ K Pmax , △ K I = [△ K Imin , △ K Imax . Here, the stable parameter ranges are taken according to the actual system debugging experiments: △ K P = [0.2, 15], △ K I = [0.1, 0.5]. And for convenience, △ K P and △ K I are normalized to the parameters △ K’ P and △ K’ I in the range of [0, 1] through the following linear transformation.

[0049]

[0050] Step 2: Variable Fuzzification According to the relevant performance requirements of the actual system, the control input quantity is the displacement error e 1 ( t ) = r ( t ) - y 1 ( t ), with a variation range of [-50, 50] mm, and it is divided into 11 levels of {-5, -4, …, -1, 0, …, 4, 5}. The quantization factor α 1 = 5 / 50, so the universe of discourse of the displacement error is U1 = [-5, 5], which is represented by the fuzzy subset CP1 = {NB, NS, ZO, PS, PB}. The synchronization error e 12 ( t ) has a variation range of [-10, 10] mm, and it is divided into 9 levels of {-4, …, -1, 0, …, 4}. The quantization factor is α 2 = 4 / 10, so the universe of discourse of the synchronization error is U2 = [-4, 4], which is represented by the fuzzy subsetCP 2 is represented by {NB, ZO, PB}. The controlled output quantity △ K’ P and △ K’ I vary in the range of [0, 1]. They are divided into 6 levels of {0, 1, 2, 3, 4, 5}, and the quantization factor α 3 = α4 = 5 / 1, then △ K’ P and △ K’ I have the universe of discourse U3 = U4 = [0, 5], and are represented by the fuzzy subsets DP 1 = DP 2 ={S, M, B}.

[0051] Step 3: Determination of the membership function Its specific forms include curves such as triangular, rectangular, trapezoidal, Gaussian, etc. Here, for all fuzzy quantities, the triangular function shown in Figure 6 、 Figure 7 as well as Figure 8 is adopted.

[0052] Step 4: Determination of the fuzzy decision rule From the fuzzy quantification of the system variables in Steps 2 and 3, it can be seen that the controller of the double-channel valve-controlled cylinder electro-hydraulic servo system belongs to a multi-input multi-output fuzzy controller. The formulation of the i-th fuzzy control rule of the fuzzy controller here can be expressed as: R i :IF( e 1 is CP 1i )AND( e 12 is CP 2i )THEN(△ K’ Pi = DP 1i ) (△ K’ Ii = DP 2i ) In the formula, CP 1i and CP 2i are fuzzy input subsets, CP 1i ∈CP 1 、 CP2i ∈CP 2 ; DP 1i and DP 2i are the fuzzy output subsets, DP 1i ∈DP 1 、 DP 2i ∈DP 2 , i = 1, 2,.., 15. These fuzzy rules can also be expressed in the implication format: R i : ( CP 1i × CP 2i ) → ( DP 1 + DP 2 ) In the formula, × is the Cartesian product, and + is the union operation.

[0053] Thus, the fuzzy control relationship of this two-input two-output fuzzy controller can be obtained as: ( k = 1, 2,; j = 1, 2) The fuzzy rules in the above formula can be represented by Table 1. The fuzzy logic inference rules in this table are obtained by actual debuggers through a large number of experiments and have passed the tests of rule integrity, compatibility, and interference.

[0054] Table 1: Fuzzy PID Control Decision Planning Table for Adjustment Channels

[0055] Step Five: Fuzzy Control Output and Its Defuzzification According to Table 1, the relationship between the corresponding control output and the control input can be described as:

[0056] In the formula, represents the sup-min composition inference decision.

[0057] Through the above steps, △ K’ P and △ K’ I are obtained, and then according to △ K’ P and △ K’ IObtain the gain parameters of the first PID controller, and then, based on the gain parameters of the first PID controller, control the flow rate and pressure of the hydraulic cylinder. Finally, based on the flow rate and pressure of the hydraulic cylinder, control the synchronous lifting of the double scissor lift work platform.

[0058] Adopt the cross-coupled fuzzy PID synchronous control strategy. According to the output errors of multiple channels, automatically adjust, modify, and improve the PID control parameters of the adjustment channels during the control process, so as to adjust the output flow rate and pressure of each hydraulic cylinder in real time, enabling synchronous control of each hydraulic cylinder. The double scissor lift work platform of this embodiment has the advantages of high control accuracy, small synchronous error, strong anti-overturning performance, and safe operation.

[0059] The above has introduced the double scissor lift work platform and system provided by the present invention in detail. Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A double scissor lift device, characterized in that: include: The upper base is fixedly provided with a first pair of slide grooves; A lower base, arranged opposite to the upper base and fixedly provided with a second pair of slide grooves; The scissors-fork mechanism comprises a first scissors-fork mechanism and a second scissors-fork mechanism which are arranged opposite to each other. The first scissors-fork mechanism and the second scissors-fork mechanism are hinged by a pin. The bottom front end of the first scissors-fork mechanism and the bottom front end of the second scissors-fork mechanism are both slidably connected to the second pair of slide grooves by the pin. The bottom rear end of the first scissors-fork mechanism and the bottom front end of the second scissors-fork mechanism are both fixedly connected to the second pair of slide grooves. The upper front end of the first scissors-fork mechanism and the upper front end of the second scissors-fork mechanism are both slidably connected to the first pair of slide grooves by the pin. The upper rear end of the first scissors-fork mechanism and the upper front end of the second scissors-fork mechanism are both fixedly connected to the first pair of slide grooves.

2. The double scissor lift device according to claim 1, characterized in that: The pin connecting the bottom front end of the first scissor mechanism and the bottom front end of the second scissor mechanism is a bottom pin, and the first slider is hinged at both ends of the bottom pin, and the first slider is slidably connected to the second pair of slide grooves.

3. The double scissor lift device according to claim 1, characterized in that: The pin connecting the upper front end of the first scissor-fork mechanism and the upper front end of the second scissor-fork mechanism is an upper pin, and the second slider is hinged at both ends of the upper pin, and the second slider is slidably connected to the first pair of slide grooves.

4. The double scissor lift device according to claim 1, characterized in that: It also includes a hydraulic cylinder, a connecting plate is fixedly arranged on the scissor mechanism, two ends of the hydraulic cylinder are hinged to the pin sleeve, the pin sleeve is slidably connected to the pin, and the pin is hinged to the connecting plate.

5. The double scissor lift device according to claim 4, characterized in that: The hydraulic cylinders are evenly distributed on the scissor-type mechanism.

6. The double scissor lift device according to claim 1, characterized in that: A main platform is also arranged on the upper base, and the main platform is connected to the upper base through a rotating device. A left telescopic platform and a right telescopic platform are connected to two sides of the main platform through chains.

7. A double scissor lift system, characterized in that: The double scissor lift working device as claimed in claims 1 to 6 comprises the double scissor lift working device as claimed in claims 1 to 6, and further comprises a displacement monitoring component, a PLC controller, a switch component and a power component; A displacement monitoring component, used to detect the displacement of the hydraulic cylinder; A PLC controller, connected to the displacement monitoring component, for generating a first control instruction according to the error value of the displacement; a switch component, used to switch its own state from an initial state to a first state, or switch its own state from an initial state to a second state according to the first control instruction, and generate a second control instruction at the same time, wherein the first state is to allow hydraulic oil to enter the hydraulic cylinder, and the second state is to allow hydraulic oil to flow out of the hydraulic cylinder; The power component is connected to the switch component and is used to receive the second control instruction to start the motor of the power component.

8. The double scissor lift system according to claim 7, characterized in that: The power components include: an electric motor and an oil tank; An oil tank, connected to the switch component and used for storing hydraulic oil; The electric motor is connected to the oil tank and is used to drive the hydraulic oil in the oil tank to flow in or out.

9. The double scissor lift system according to claim 7, characterized in that: The switch component is a four-position three-way proportional reversing valve.

10. The double scissor lift system according to claim 7, characterized in that: The PLC controller is used to: Obtaining a displacement deviation and a displacement error of the hydraulic cylinder, wherein the displacement deviation is obtained based on an input amount and a displacement change amount corresponding to the system adjustment channel, and the displacement error is obtained based on an input amount and a displacement change amount corresponding to the system free channel; Obtaining a synchronization error based on the displacement deviation and the displacement error; Obtaining a proportional gain parameter increment and an integral gain parameter increment of the system adjustment channel based on the displacement deviation and the synchronization error; Determine the fuzzy rule based on the displacement deviation, the displacement error, the synchronization error, the proportional gain parameter increment and the integral gain parameter increment; Adjusting the gain parameter of the system adjustment channel based on the fuzzy rule to obtain an adjusted gain parameter; adjusting the flow and pressure of the hydraulic cylinder based on the adjusted gain parameters; The synchronous lifting of the double scissor lift work platform is controlled based on the flow and pressure of the hydraulic cylinder.

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