170results about How to "Reduce structural complexity" patented technology

The utility model provides a stone material unloading machine's board material dump receiving mechanism, including the supporting plate device, the blanking device and the broken part, the supporting plate device can lift and reciprocatingly move and suspend in the front side of stone processing position, the blanking device is arranged in the back below of supporting plate device, the broken part can lift and reciprocatingly move and be arranged in the clearance between two pieces of vertical stone board, and make the vertical stone board of processing position and the connecting part of lower end realize fracture, the supporting plate device passes through the lift and horizontal movement and will be broken stone board on stone processing position stable receiving transition to the blanking device surface, the utility model discloses a reasonable cooperation through supporting plate device and blanking device, can be stable receiving vertical state's stone board after the stone board broken, avoid directly using the sucking disc and carrying on adsorption, reduced equipment structure complexity and operation risk.

The utility model discloses a code changing structure, a lock structure and a padlock, which comprise a plurality of press keys for pressing, a locking plate matched with the press keys for locking and a lock beam connected on the locking plate, a plurality of limiting pieces capable of moving along the moving direction of the press keys are arranged on the locking plate, bulges are arranged on the side surfaces of the press keys corresponding to the positions of the limiting pieces, and the lock beam is connected with the lock beam. The limiting piece is provided with a notch used for allowing the protrusion to go in and out in a matched mode. The lock beam and the locking plate are fixedly connected in the pulling-out direction of the lock beam, and the lock beam and the locking plate are rotationally connected in the circumferential direction. And when all the keys are pressed down until the bulges correspond to the notches of the corresponding limiting pieces, the lock beam is unlocked, the lock beam is pulled out to drive the locking plate to move until at least part of the bulges enter the notches, and the keys axially move to drive the limiting pieces to move to replace the password. The complexity of a code changing structure can be simplified, the assembling cost is reduced, the occupied structural space is reduced, and the production efficiency is improved.

The present application relates to a kind of core-pulling module of plastic forming die, including inclined top module, inclined top module includes U-shaped seat block, the directional plate of transverse fixed at the top opening of U-shaped seat block, oblique square column is connected in the directional plate and is active, and the traction strip that is transverse and is arranged in the inside of U-shaped seat block to have front and rear translation function and is connected with the lower end of oblique square column;Inclined top module further includes rotatable connection in the inside rear side of U-shaped seat block transmission gear and rotatable connection in the inside of U-shaped seat block and meshing in the front upper of transmission gear reversing gear;Inclined top module further includes vertical arrangement and meshing in the rear of transmission gear driving rack;The present application reduces both the complexity of the structure of mould, and the processing and manufacturing difficulty of mould, to reach the effect of time-saving and labor-saving and reduce manufacturing cost.

The invention discloses an antenna and terminal equipment, the antenna comprises a first radiator and at least one second radiator, and the first radiator generates a first resonant frequency; each of the at least one second radiator and the first radiator are arranged in an outer shell and are coupled in a suspended manner to form resonance, the at least one second radiator and the first radiator resonate to generate at least one second resonant frequency, and the second resonant frequency is different from the first resonant frequency. According to the embodiment of the invention, the second radiating body which is suspended relative to the first radiating body is adopted, so that the structural complexity of the first radiating body can be reduced, and the processing difficulty of the first radiating body is reduced; the first radiating body generates the first resonant frequency, and the second radiating body and the first radiating body generate the second resonant frequency, so that multiple functions of the antenna can be conveniently realized, the antenna performance is improved, and the application range is widened.

The utility model relates to alumina microsphere preparation technical field, concretely relates to a kind of preparation device of hundred-micron alumina microsphere, including feeding device, with the feeding pipe of feeding device connection, still including heating kettle, solvent cylinder being set in heating kettle, rotating shaft being rotationally arranged in solvent cylinder, rotating cavity being set in the lower end of rotating shaft and located in solvent cylinder, multiple micropore tubes being annularly arranged on rotating cavity, stirring paddle being set in the lower end of rotating cavity, servo motor being set in the upper end of heating kettle;The upper end of heating kettle is provided with the jack for the insertion of solvent cylinder, the rotating shaft is rotationally arranged in the upper side of heating kettle and is drivingly connected with servo motor, the upper end of rotating shaft is connected with feeding pipe, and the lower end is inserted in solvent cylinder.This device preparation hundred-micron alumina microsphere's specific surface area is large, and particle size is uniform, and equipment structure is not complex, easy to operate, and low in cost.

This invention discloses a carbon fiber composite material with in-situ monitoring and self-healing functions and its preparation method. The carbon fiber composite material includes a carbon fiber reinforcement and a functional resin matrix impregnated and cured within the carbon fiber reinforcement. The functional resin matrix is ​​formed from epoxy resin, a fatty amine curing agent, a photoresponsive self-healing agent, lamellar boron nitride nanoparticles, a dispersant, and a composite photoinitiator. The photoresponsive self-healing agent retains at least a portion of its photopolymerizable state under 365nm ultraviolet light. During preparation, lamellar boron nitride nanoparticles are first dispersed in epoxy resin, then the photoresponsive self-healing agent and composite photoinitiator are added, followed by the addition of the fatty amine curing agent, and the carbon fiber fabric is vacuum impregnated and cured at room temperature or low temperature. In use, the crack damage area is determined based on the change in 365nm transmittance relative to a reference value, and the self-healing agent polymerization is initiated by targeted irradiation with 365nm ultraviolet light. The lamellar boron nitride nanoparticles enhance the thermal conductivity and interfacial bonding of the repair area. This invention can achieve damage localization and in-situ repair without the need for implanted sensors and is applicable to carbon fiber reinforced composite material structures.

This invention provides an ink mixing device for a packaging box printing machine, relating to the field of ink processing technology. The ink mixing device for the packaging box printing machine includes a mixing tank and a bottom tank; it also includes a drive motor, the output end of which is connected to a pressing mechanism and a reciprocating mechanism. The pressing end of the pressing mechanism is connected to a piston, which moves within a metering mechanism. An adjustment mechanism for metering is also provided on the outside of the metering mechanism. Inside the mixing tank, a stirring assembly and a scraper are provided for ink mixing. The stirring assembly and scraper are driven by the drive motor. The reciprocating end of the reciprocating mechanism is connected to a scraper ring for scraping the inner wall of the mixing tank. This invention achieves coordinated operation of metered ink delivery, efficient mixing, and automatic tank wall cleaning by simultaneously driving the pressing mechanism, stirring assembly, and reciprocating mechanism with a single drive motor, effectively reducing equipment energy consumption and structural complexity.

The invention relates to a rotating shaft assembly, a grounding part and electronic equipment, the rotating shaft assembly comprises a rotating shaft and the grounding part, the grounding part is arranged between the rotating shaft and a rotating shaft back cover in the electronic equipment and is electrically connected with the rotating shaft back cover and the rotating shaft to form a grounding circuit, and the grounding part comprises a voltage limiting element. When the voltage in the grounding circuit is greater than or equal to a first threshold value of the voltage limiting element, the voltage limiting element conducts the grounding circuit; when the voltage in the grounding circuit is smaller than the first threshold value of the voltage limiting element, the voltage limiting element disconnects the grounding circuit. The rotating shaft assembly is simple in structure, easy to manufacture and low in cost, the ESD grounding requirement of the rotating shaft back cover and the daily use requirement of a user can be met at the same time, the service life of a metal appearance part outside the electronic equipment is prolonged, and the use safety of the electronic equipment is improved.

This application provides a method, apparatus, and electronic device for controlling a motor. Without using a Hall sensor or other device to detect motor speed, the processor in the electronic device calculates the peak voltage of the AC power supply driving the motor using a zero-crossing detection signal. Then, based on the peak voltage, it determines when the motor speed needs adjustment. The voltage control circuit adjusts the AC power supply voltage to the motor, thereby achieving motor speed adjustment. Therefore, this application reduces the structural complexity and cost of the electronic device while controlling the motor, and also improves the user experience of the electronic device.

The present application relates to the technical field of tunnel construction, in particular to a tunnel shield support non-blasting excavation method and equipment, the excavation method comprises four steps of drilling and pumping, concrete solidification, excavation of the surrounding rock and waterproof treatment, the method forms a concrete closed-loop shield support system by drilling and pumping in advance, a stable closed-loop support structure is formed before the excavation of the surrounding rock, effectively preventing the large deformation of soft rock and the rock burst phenomenon caused by stress release in hard rock during tunnel excavation; the system anchor rod, concrete spraying construction and explosive blasting process in the traditional support system are cancelled, which is safe and reliable, and has high economic benefits. The excavation equipment shares a propulsion mechanism through the spiral drill module and the reverse circulation down-the-hole drill module, without the need for separate propulsion devices for the two drill bits, the feed is achieved by driving the arc-shaped limiting piece with a chain, and the limiting block, the worm and the ring worm gear transmission self-locking function are matched to ensure the positioning accuracy of the drill bit during drilling, and to reduce the complexity of the equipment structure and the purchase and maintenance cost.

The invention discloses a sparse time sequence Bayesian network construction method and system based on power distribution network topological constraints, and the method specifically comprises the steps: constructing a power distribution network topological graph, and calculating an adjacent matrix between nodes and a k-hop neighborhood matrix Nk; based on the power distribution network topology distance information and the matrix Nk, generating a hard constraint rule, and constructing a topology dependence mask matrix M; calculating an electrical influence range of the fault point on surrounding nodes to obtain an electrical influence matrix E; if the electrical influence coefficient of one node on the other node is smaller than a set value, deleting the corresponding dependent edge; introducing a data source reliability matrix R, and performing hard deletion or soft weakening on edges with reliability lower than a threshold value; combining the matrixes M, E and R to synthesize a sparse structure matrix S; and taking the matrix S as a space skeleton, adding a time dimension autoregression edge, and constructing a complete sparse time sequence Bayesian network. According to the invention, by guiding the rarefaction of the network structure, the number of network edges and the number of parameters are effectively reduced, and the trainability and reasoning efficiency of the model are improved.

This invention provides a wireless, passive force-position implantable growth monitoring system and its fabrication method for early-onset scoliosis correction. The system includes: a connected compressible capacitive sensor and a flexible wireless antenna coil; the compressible capacitive sensor is connected to a self-growing early-onset scoliosis correction implant growth rod, and the flexible wireless antenna coil is disposed within the body. The compressible capacitive sensor and the flexible wireless antenna coil together constitute an LCR resonant circuit; the compressible capacitive sensor monitors the pressure changes caused by the elongation of the self-growing early-onset scoliosis correction implant growth rod during tissue or bone growth, thereby causing changes in capacitance and resulting in changes in the resonant frequency of the LCR resonant circuit; the resonant frequency change is detected and read out wirelessly via an external readout device. This system is designed to meet the needs of digital rehabilitation, requires no internal power supply, and has a stable structure, making it suitable for growth monitoring after early-onset scoliosis correction surgery.

A self-organizing swarm robot system and control method based on cellular soft and hard mechanisms are disclosed. The system includes several individual robots. Each robot includes an upper shell, a middle support, a lower support chassis, electrically driven legs, a magnetically connected actuator, a PCB control board, and light-emitting elements. The PCB control board is equipped with an ESP-NOW wireless communication module, a light sensor, and a multi-pose sensor. The magnetically connected actuator includes static and dynamic actuators alternately distributed along the circumference. This invention can simulate the adhesion force regulation and morphological expansion and contraction mechanism between biological cells, achieving dynamic control between swarm robots under mechanical action. It exhibits high flexibility and fast response speed, enabling multi-degree-of-freedom movement and posture adjustment in complex environments. By using ESP-NOW wireless communication technology in conjunction with light sensors and multi-pose sensors to construct a high-precision distributed sensing and control system, it supports the self-organization, collaboration, and task execution capabilities of swarm robots in weak information environments.

The application discloses a high-isolation dual-radiation-mode dual-frequency filtering antenna, and relates to the technical field of antennas of wireless communication terminals; the high-isolation dual-radiation-mode dual-frequency filtering antenna comprises a first dielectric substrate to a fourth dielectric substrate which are sequentially arranged from bottom to top; a pair of differential feeding lines arranged on the lower surface of the first dielectric substrate; an intermediate metal surface arranged between the first dielectric substrate and the second dielectric substrate; a pair of feeding extension branches arranged between the second dielectric substrate and the third dielectric substrate; a circular patch arranged between the third dielectric substrate and the fourth dielectric substrate; an upper metal surface and a ring-shaped patch arranged on the upper surface of the fourth dielectric substrate; a feeding probe vertically penetrating the center of each dielectric substrate; and a plurality of groups of metalized short-circuit through holes; the application utilizes the resonant characteristics of the structure itself and electromagnetic mixed coupling effects to obtain dual-frequency dual-band filtering responses; and adopts a feeding mode combining differential feeding and probe feeding and orthogonal mode excitation to realize high isolation between the dual-frequency bands.

This utility model discloses a telescopic leg tube and support frame with a quick locking and unlocking function. The telescopic leg tube includes a linkage rod and several sequentially cascaded leg tube assemblies. The linkage rod passes through several leg tube assemblies. Each leg tube assembly includes an outer tube, an inner tube, a synchronizing sleeve, a connecting sleeve, and a locking component. The synchronizing sleeve can move axially in a first direction relative to the linkage rod when the linkage rod rotates in the forward direction, thereby driving the locking component through the inner tube to restrict the relative movement between the inner tube and the outer tube of the next-level leg tube assembly. Alternatively, the synchronizing sleeve can move axially in a second direction relative to the linkage rod when the linkage rod rotates in the reverse direction, thereby driving the locking component through the inner tube to release the restriction on the relative movement between the inner tube and the outer tube of the next-level leg tube assembly. Through the above structure, multiple sets of leg tube assemblies can be simultaneously locked and unlocked by the linkage rod, making the structure uniform, which not only improves the convenience of use but also reduces the structural complexity and production cost.

The application provides a microwave energy receiving system of a spatial solar power station of a multiplex ground photovoltaic power station, which comprises a photovoltaic power station basic unit, an energy receiving and converting unit, a grid-connected energy management unit and a power generation mode switching unit; the energy receiving and converting unit is arranged based on the photovoltaic power station basic unit; the energy receiving and converting unit comprises a receiving panel, a photovoltaic assembly and a microwave assembly; the photovoltaic assembly and the microwave assembly are arranged on the receiving panel; the output end of the photovoltaic assembly and the output end of the microwave assembly are connected in parallel to a bus line to form a photovoltaic output loop and a microwave rectification loop; the bus line is connected to the grid-connected energy management unit; the grid-connected energy management unit is connected to an energy storage device and / or a power grid; and the power generation mode switching unit is connected to the energy receiving and converting unit to control the energy receiving and converting unit to switch between a photovoltaic power generation mode and a microwave receiving mode. The application is arranged based on the photovoltaic power station, and the structural complexity and construction cost of the system are reduced.

The invention relates to the technical field of wind tunnel test devices, in particular to a contraction section structure and a wind tunnel. The contraction section structure comprises a contraction section flange, the contraction section flange is provided with a contraction section molded surface, the contraction section molded surface is arranged to be a gradually-contracted section, supporting assemblies are arranged in the contraction section flange, the supporting assemblies are arranged in the length direction of the contraction section flange at intervals, and the supporting assemblies are used for providing supporting space for the outer frame and conducting flow guiding. The contraction section structure reduces structural complexity and manufacturing cost on the premise of meeting test requirements, has good machining feasibility and installation convenience while ensuring basic flow field performance, and can be widely applied to wind tunnel design in a limited space.

The application discloses a kind of laser-assisted drilling rock breaking intelligent control system and method, comprising: perception module, for obtaining the state information of each component of laser drill, tunneling parameter and drill drilling force;Decision module is used to determine whether the operation of laser drill is normal according to the state information of each component of laser drill, determine the surrounding rock grade under the current tunneling state according to tunneling parameter, and determine the drilling pressure difference between each drill tooth according to drill drilling force, and determine whether the drilling direction of drill is deviated by the drilling direction deviation occurrence threshold value;Execution module is used to determine whether to issue alarm and close laser drill according to the operation of laser drill determination result, select to start corresponding drilling mode according to surrounding rock grade, and adjust laser beam exit angle according to the drilling direction of drill determination result.Advantages: improve tunneling efficiency, ensure drilling stability and safety.

A mouse comprises a shell assembly and a core assembly; wherein the shell assembly comprises a bottom plate, a face shell and a support; the bottom plate is opposite to the face shell and connected to form a containing space therebetween; the core assembly is arranged on the bottom plate and located in the containing space; the face shell comprises first and second side walls opposite in the width direction of the mouse; the support is located in the containing space and connected between the first and second side walls. By omitting the middle shell in the traditional mouse and arranging the core assembly on the bottom plate, the structural complexity of the mouse can be effectively reduced, and the disassembly difficulty and weight of the mouse can be reduced; by forming a structural support in the interior of the face shell with the support, the face shell can maintain a stable structure, the structural strength or deformation resistance of the face shell can be improved, and the support can be used as a mounting carrier for auxiliary components such as side keys, so that the mouse structure and space can be fully utilized.

The utility model relates to a vertical tea uniform stacking machine, it includes: machine body, tea scattering mechanism and opening and closing mechanism, machine body top is provided with the feed port, bottom is provided with the discharge gate, is equipped with the layered structure in the machine body, the layered structure is used for separating the inside of machine body into upper chamber and lower chamber, and is provided with a plurality of horizontal side -by -side arrangement's blanking port, blanking port is used for the intercommunication upper chamber and lower chamber, and upper chamber intercommunication feed port, lower chamber intercommunication discharge gate. Tea scattering mechanism includes tea scattering ware, and tea scattering ware rotatably is located in the upper chamber, and is arranged in the just below of feed port. Opening and closing mechanism includes door body, driving part and transmission part, the number of door body is same with the number of blanking port, and each door body and each blanking port one to one correspondence, door body and driving part all with machine body movably connect, and each door body is respectively with driving part transmission connection through transmission part, to when driving part relative machine body activity, relative machine body activity and open or close each blanking port.

This utility model discloses a multi-directional floating connector assembly in the field of electronic device connector technology, including a first connector, a mating second connector, and a first mounting plate for mounting the first connector; the first mounting plate has a first through hole and a second through hole, the fixed end of the first connector has a flange with a threaded hole, and the mating end of the first connector extends through the second through hole; a first radial gap is provided between the first connector and the second through hole, a second radial gap is provided between the sleeve and the second through hole, and an axial distance is provided between the sleeve and the first mounting plate; this structure can realize the axial and radial floating adjustment of the connector during the insertion process, improve the connector's adaptability to installation errors and insertion deviations, has a simple structure, strong installation fault tolerance, and is suitable for connection needs in complex or high-density installation environments.

The utility model discloses a kind of perforating device of bundled straw biomass fuel, including frame, and frame is provided with perforating device, and perforating device includes linear power mechanism, mounting seat and punch assembly, the end surface of mounting seat is connected with linear power mechanism, and the other end surface is provided with punch assembly;The bottom of frame is provided with the positioning assembly for positioning straw bundle, and linear power mechanism drives punch assembly to carry out punching operation to the straw bundle after positioning. Linear power mechanism includes any one in hydraulic cylinder, cylinder, electric cylinder, and hydraulic cylinder is connected with hydraulic pump group and control valve group, cylinder is equipped with gas source equipment and solenoid valve, electric cylinder is electrically connected with servo driver and controller. The utility model punches in straw bundle, obtains straw bundle with air hole, increases airflow flow in straw bundle, effectively improves the combustion efficiency of whole straw bundle, can effectively reduce the volume and structure of combustion furnace, reduces combustion furnace investment cost.

The camera cleaning device provided by the embodiment of the application can utilize the reciprocating swing of the rear rain wiper motor to provide driving force for the driving cam, and convert the rotary driving force into reciprocating linear motion of the transmission member through the special-shaped side surface of the driving cam, so that the transmission member can drive the cleaning assembly to clean the rear camera reciprocatingly. Therefore, the camera cleaning device can clean the rear camera through a pure mechanical structure without integrating a power source, so that the structural complexity and cost of the camera cleaning device can be greatly reduced.

This application relates to the field of atomization technology and provides a smoke generator, including a housing, an atomizer, a fan, and a separator. The separator is disposed inside the housing, and a first side of the separator forms a smoke chamber with the housing. The separator has a second side opposite to the first side, which forms an mounting cavity with the housing. At least a portion of the housing corresponding to the smoke chamber is made of a transparent material. The housing includes a top wall and side walls surrounding the outer periphery of the top wall. The separator includes a top plate and a side plate surrounding the outer periphery of the top plate. The top wall and the top plate form a diffusion channel for the smoke chamber, and the side plates and at least a portion of the side walls form a sinking channel for the smoke chamber. A mist outlet channel is connected to the diffusion channel, and the mist outlet channel is connected to the mist outlet of the atomizer and the diffusion channel, respectively. The smoke generated by the atomizer flows sequentially through the mist outlet channel and the diffusion channel and then flows downward to the sinking channel. This makes the smoke generator simple in structure and easy to assemble.

The application discloses a kind of machine arm joint loosening and folding structure, including center disc cantilever assembly, machine arm folding assembly and threaded sleeve assembly.The application is tightly matched with center disc inner part by threaded sleeve kit, and threaded sleeve kit is pressed tightly machine arm inner part, so that machine arm folding assembly and center disc cantilever assembly are realized stable connection, simultaneously, the threaded sleeve loosening assembly designed can be loosened to threaded sleeve assembly, so as to increase the safety and reliability of unmanned aerial vehicle flight.The first pivot pin and the second pivot pin of the first pivot pin and the second pivot pin connected by machine arm folding assembly and folding adapter are rotated twice around the shaft, so that machine arm folding assembly can be folded to the smallest storage size space without increasing structural weight and complexity when folding without interfering with other components of unmanned aerial vehicle.

The embodiment of the present application provides a kind of light perception structure group, spectral imager and its use method.The light perception structure group includes hot light detector, including at least one feature unit structure, the feature unit structure includes multiple metal nano structures;And mobile device, including at least one moving component, the moving component is set to one-to-one group corresponding with the feature unit structure;The moving component is set to drive the feature unit structure to move, to change the relative position of the feature unit structure and the light source to be detected.The light perception structure group provided in the embodiment of the present application is set by moving component, and the feature unit structure is moved by moving component, to change the relative position of the feature unit structure and the light source to be detected, reduces the structural complexity of spectral imager, and realizes the perception of spectrum in ultra-wideband range.

The utility model discloses a kind of storage box of vehicle and vehicle, storage box includes: box main body, lid, clamping assembly and cooperation structure;Box main body is equipped with opening;Lid is rotatably arranged in opening;Clamping assembly is arranged in lid, clamping assembly is equipped with clamping portion;Cooperation structure is arranged in box main body by first connecting piece, cooperation structure is suitable for clamping clamping portion, to fix lid.The utility model fixes cooperation structure on box main body by first connecting piece, cooperation structure and box main body are both independently formed, reduce the overall structure complexity of box main body, reduce the difficulty of manufacturing and forming, shorten manufacturing cycle, reduce production cost, improve yield, while guaranteeing the stability of lid positioning Simplify box structure, reduce manufacturing cost and process difficulty.

The invention discloses a displacement sensor based on electromagnetic induction and a displacement measuring method, the sensor comprises a sensing and signal generating unit, a signal conditioning and converting unit and a digital processing and resolving unit, the sensing and signal generating unit comprises a multi-path analog switch and an LC oscillating circuit, inductance elements in the LC oscillating circuits are composed of displacement sensitive elements, and the multi-channel analog switch is used for selectively connecting the displacement sensitive elements to the corresponding LC oscillating circuits. The signal conditioning and converting unit is used for shaping the oscillation signal into a digital pulse signal; and the digital processing and resolving unit can measure the frequency of the digital pulse signal by adopting an equal-precision frequency measurement method and resolve the displacement according to the change of a frequency value. According to the invention, stable output amplitude and high frequency stability are maintained in a wide frequency range, and the stability of signals is ensured; in addition, measurement errors of a traditional frequency measurement method at low frequency are eliminated, and high-precision measurement in a full-scale range is guaranteed.

The utility model discloses a telescopic foot tube and a support frame capable of quickly unlocking and locking, the telescopic foot tube comprises a linkage rod and a plurality of foot tube components which are sequentially cascaded, the linkage rod is arranged on the plurality of foot tube components in a penetrating manner, and each foot tube component comprises an outer tube, an inner tube, a push-pull component and a locking component; the push-pull assembly can move in the first direction in the axial direction relative to the linkage rod when the linkage rod rotates in the forward direction, so that the inner pipe drives the locking assembly to limit relative movement between the inner pipe and the outer pipe of the next-stage foot pipe assembly. Or, the push-pull assembly can move in the second direction in the axial direction relative to the linkage rod when the linkage rod rotates reversely, so that the locking assembly is driven by the inner pipe to relieve the limitation on the relative movement between the inner pipe and the outer pipe of the next-stage foot pipe assembly; by means of the structure, the multiple foot tube assemblies can be linked through the linkage rods at the same time for locking and unlocking, the structure is made to be uniform, use convenience is improved, and structural complexity and production cost are reduced.