30results about How to "Realize support positioning" patented technology

The invention provides a detection and positioning device for a checking tool for automobile parts, which can simply and conveniently realize the positioning of the parts on the checking tool and ensure the detection quality of the automobile parts. The detection and positioning device comprises a detection simulation block seat, and is characterized in that a positioning column is arranged on the detection simulation block seat, a detection and positioning end corresponding to the shape of an automobile part is arranged on the positioning column, and a positioning and detection surface matched with the automobile part is arranged at the detection and positioning end.

The invention discloses a pulling belt type round log splicing machine and a round log splicing method. The pulling belt type round log splicing machine comprises a frame, pulling belts, drawing cylinders, at least two outer supporting frames and inner supporting frames. The outer supporting frames are used for supporting the outer wall of a hollow round log, the inner supporting frames are used for supporting the inner wall of the hollow round log and arranged at two ends of the hollow round log, and the outer walls of the inner supporting frames match with the inner wall of the hollow round log. The outer supporting frames are mounted on the frame and uniformly distributed along the length direction of the hollow round log, and the radian of the inner walls of the outer supporting frames is uniform with that of the outer periphery of the hollow round log. A body of each drawing cylinder is mounted on the frame, a piston rod of each drawing cylinder is connected with one end of the corresponding pulling belt, and the other end of each pulling belt is wound on the hollow round log prior to being connected with the frame. The pulling belt type round log splicing machine and the round log splicing method have advantages that structural simplicity and convenience and quickness in operation are achieved, and positioning accuracy and high efficiency in a sector splicing process are realized; owing to positioning and supporting of the inner supporting frames in preliminary pressurizing, displacement and deformation of the hollow round log are avoided at a preliminary stage, and hollow round log splicing effects are improved.

The invention belongs to the technical field of welding clamps, and particularly relates to a self-adaptive positioning combination clamp for welding curved-surface panels. The self-adaptive positioning combination clamp comprises a first rotary supporting rod, a second rotary supporting rod, a first locking bearing, a second locking bearing, a ball head, a torsional spring, a limiting spring, a clamping spring, a spring stop dog, a driving supporting seat, a driven supporting seat, an angle seat, a bottom plate, a locking device, a power device, a coupling device, a fixed rotary shaft and a clamping device. Workers opens the clamping device, the welded curved-surface panels are placed on the clamp, the rotary supporting rods rotate around the fixed rotary shaft, the torsional spring is automatically adjusted, and a balance state is achieved; locking is carried out through the power device, then clamping is carried out, and welding is started; and the welding is completed, the clampingdevice is opened, the curved-surface panels are taken out, the rotary supporting rods are automatically adjusted according to different curved-surface panels to adapt to the welding of the curved-surface panels with different shapes, the time of designing and producing the welding clamp is shortened, the clamp cost is reduced, and the production cycle is shortened.

The invention relates to a device and a method for adjusting the thickness of a steel bar protective layer. The device for adjusting the thickness of the steel bar protective layer comprises an upper cushion block, a lower cushion block and supporting legs connected to the lower cushion block through connecting rods, wherein the upper cushion block is provided with at least three upper steel bar supporting long holes and upper steel bar containing openings corresponding to the upper steel bar supporting long holes; the lower cushion block is provided with corresponding lower steel bar supporting long holes and lower steel bar containing openings corresponding to the lower steel bar supporting long holes; the distance between the top face of the upper cushion block and the bottom faces of the supporting legs is the thickness of a floor needing to be constructed; in any two upper steel bar supporting long holes and any two lower steel bar supporting long holes, the distance between the tops of the upper steel bar supporting long holes and the top face of the upper cushion block is equal to the thickness of an upper steel bar protective layer, and the distance between the bottoms of the lower steel bar supporting long holes and the bottom faces of the supporting legs is equal to the thickness of a lower steel bar protective layer; and floors with different thicknesses of upper steel bar protective layers and lower steel bar protective layers can be constructed, and the application range is widened.

The invention belongs to the technical field of telescopic arm systems and engineering machines, and particularly relates to a combined telescopic arm system and engineering machine. The combined telescopic arm system and engineering machine comprises a vehicle body and lifting air cylinders. Fixed barrels are fixed to the upper end of the vehicle body. The lifting air cylinders are mounted on thetwo sides of the lower end of the vehicle body. Linkage rods are mounted on the two sides of supporting frames. A fixed seat is fixed to the left side of the vehicle body. A telescopic arm is fixed to the upper end of a mounting seat. A moving ring is mounted on the outer side of the telescopic arm. A compartment is fixed to the right side of the vehicle body. Work blocks are fixed to the two sides of the compartment. A work rod is mounted on the outer portion of a function rod. A locating groove is formed on the outer wall of the compartment. According to the combined telescopic arm system and engineering machine, operation rods are rotated, so that moving plates stretch out from the interior of the supporting frame, the lifting air cylinders are further started and drive the supportingframes and supporting cushions at the lower ends of the moving plates to extrude the ground, supporting and locating to the whole position of the device are achieved, and the overall work stability ofthe device is guaranteed.

The width dynamically adjustable conveying device of the present invention is to solve the above-mentioned problems existing in the prior art and obtain the specific shape size and position of the current package based on visual recognition technology, and adopt the method of randomly adjusting the side baffles of the conveying device The opening and closing angle is expected to realize dynamic adjustment of the conveying width at any time and is suitable for fully automatic directional conveying and tallying of multi-standard parcels, so as to realize unimpeded passage of parcels, improve conveying efficiency and prevent congestion. It includes a frame and a visual recognition device arranged vertically above the frame; at least on the baffle on one side of the frame, there is an adjustable baffle driven and connected by an angle adjustment device; the angle adjustment device has a support A rod assembly and a push rod assembly, the push rod assembly includes an electric cylinder installed on the baffle, the output shaft of the electric cylinder is connected to one end of the connecting rod through a connecting fork and a joint bearing, and the other end of the connecting rod is connected to the adjustment baffle through a joint bearing; Connect the support rod assembly between the frame and the adjustment baffle.

The invention discloses a flaw detection device for cable saddle groove clapboard welding seams and belongs to the field of the flaw detection device. The flaw detection device comprises a holder, walking modules, a positioning module, an adjustment module and a probe. The walking modules are mounted at the bottom of the holder. A support column is set at the top of the holder. The support columnis set horizontally. The positioning module slidably sleeves the support column. An elastic element is set between the positioning module and the support column. One end of the elastic element is connected with the positioning module, and the other end of the elastic element is connected with the support column. The adjustment module is slidably mounted on the positioning module. The probe is rotationally mounted on the adjustment module. According to the flaw detection device, the flaw detection of the saddle groove clapboard welding seams can be realized.

The invention provides a locating device for constant-velocity universal joints, and belongs to the technical field of work-piece locating. The locating device solves the problem that the constant-velocity universal joints cannot be held or located by universal clamps in the prior art. The locating device for the constant-velocity universal joints comprises a lower guide plate and an upper guide plate; a plurality of constant-velocity universal joint direction controllers are arranged in the length directions of the guide plates, the distance between every two constant-velocity universal joint direction controllers is an integral multiple of the circumferential distance of windows on the constant-velocity universal joints, and each constant-velocity universal joint direction controller comprises two opening-closing plates capable of extending into the constant-velocity universal joint windows; rotary drums are arranged on the guide plates in a rotating mode, the guide plates are provided with rotation control mechanisms controlling the rotary drums to rotate relative to the guide plates, and the upper end faces of the rotary drums are flush with the surfaces of the guide plates; and the upper guide plate is provided with a mechanism controlling lifting and horizontal moving of the upper guide plate. According to the structural feature that the constant-velocity universal joints are provided with the constant-velocity universal joint windows, the constant-velocity universal joints can be held and located, multi-angle adjustment of the constant-velocity universal joints can be realized, and therefore the machining requirements can be met.

The invention relates to the technical field of hydrogen centralized storage equipment, and provides hydrogen centralized storage equipment for hydrogen fuel cells, aiming at hydrogen fuel cell vehicles with different specifications and models, the hydrogen centralized storage equipment not only can realize the adjustment of the installation number of hydrogen storage bottles, but also can realize the adjustment of the relative arrangement positions of a plurality of hydrogen storage bottles, is more flexible to use, and is more uniform in heat exchange. The hydrogen storage device is relatively practical and comprises a plurality of hydrogen storage bottles and a plurality of mounting frames, each mounting frame comprises a front mounting edge ring and a rear mounting edge ring, the hydrogen storage bottles are arranged between the front mounting edge rings and the rear mounting edge rings, the rear mounting edge rings are connected with a plurality of connecting rods, the connecting rods are connected with pressing nuts, the front mounting edge rings are provided with a plurality of connecting holes, and the front mounting edge rings are provided with pressing nuts. The front mounting edge ring is connected with a collecting ring, the rear mounting edge ring is connected with a collecting ring, the collecting ring is communicated with a mounting ring through a plurality of cooling pipes, the mounting ring and the collecting ring are respectively communicated with a cooling water inlet pipe and a cooling water outlet pipe, and the front mounting edge ring and the rear mounting edge ring are respectively provided with connecting rings through a front assembling frame and a rear assembling frame.

The invention discloses a lifting tooling for a hydraulic immersed pump and a lifting method and belongs to the field of ship liquid cargo handling systems. A power transmission pipe of the hydraulicimmersed pump is divided into a first transmission pipe body and a second transmission pipe body. A lifting plate is connected to a first flange and a second flange on the first transmission pipe bodyand lifts the first transmission pipe body into a liquid cargo tank. The first flange and the second flange are arranged between the lifting plate and a first supporting plate in a clamped manner, the first supporting plate and a second supporting plate support and position the first flange and the second flange on a deck, and it is guaranteed that the first transmission pipe body is mounted in an accurate position. The lifting plate is detached, the second transmission pipe body is lifted, and connection between the second transmission pipe body and the first flange & the second flange is achieved through a connecting space between the first supporting plate and the second supporting plate. The first supporting plate and the second supporting plate are detached, the second transmission pipe body is lifted into the liquid cargo tank, and the second transmission pipe body and the deck are fixed. It is guaranteed that the hydraulic immersed pump is lifted in a segmental mode, and the problem of bending caused by oscillating when the power transmission pipe is too long is relieved.

Disclosed in the invention is a mother-daughter board connector module comprising a mother-daughter board connector with a connector shell. Contact elements are arranged inside the connector shell; the front ends of the contact elements are plug ends; and the back ends of the contact elements are provided with welding pins. The connector shell is further provided with shell mounting posts. The mother-daughter board connector module also includes at least a gasket with through holes for the pins, which is located between the connector shell and a corresponding printed board. The gasket can be arranged in the following two ways: first, gasket mounting post through holes for the passing of the shell mounting posts are arranged on the gasket, and the shell mounting posts pass through the gasket mounting post through holes, and then are plugged into printed board mounting post through holes on the printed board; and second, the gasket mounting post through holes for plugging of the shell mounting posts are arranged on the gasket and the gasket mounting posts are arranged on the gasket on the opposite side of the connector shell. The invention provides the mother-daughter board connector module which can adapt to at least two board spacings.

The invention relates to the technical field of foundation pile drilling, in particular to a foundation pile drilling machine. The foundation pile drilling machine comprises a machine body and a drill rod; a supporting frame is arranged on the machine body and located under a drill rod driving element; the upper end and the lower end of an inner cavity of the supporting frame communicate with the outside; the drill rod vertically penetrates into the inner cavity of the supporting frame; a limiting assembly used for limiting swing of the drill rod is arranged in the inner cavity of the supporting frame; and when the drill rod drills holes, the supporting frame is supported on the ground. The drilling machine has the effects that in the construction process, the peripheral side of a foundation pile is limited, so that the foundation pile is not prone to large-amplitude swing in the rotating process, and the stability of the piling process is improved.

The invention belongs to the technical field of welding fixtures, and specifically relates to a self-adaptive positioning combined fixture for welding curved panels, including a No. 1 rotating support rod, a No. 2 rotating support rod, a No. 1 locking bearing, and a No. 2 locking Bearings, ball joints, torsion springs, limit springs, circlips, spring stops, active support seats, driven support seats, corner seats, bottom plates, locking devices, power units, coupling devices, fixed rotating shafts and clips Tightening device; in the present invention, workers open the clamping device, put the welded curved plate on the fixture, the rotating support rod rotates around the fixed rotating shaft, and the torsion spring is automatically adjusted to reach a balanced state, locked by the power device, and then clamped , start welding; after the welding is completed, open the clamping device, take out the curved plate, and the rotating support rod will automatically adjust according to different curved plates, which is suitable for welding of curved plates of different shapes, saving the time of designing and producing welding fixtures and reducing the fixture. cost, shortened production cycle.

The invention belongs to the field of graphitization internal furnace stringing, and discloses a signal transmission-stable combined power supply vehicle for graphitization internal furnace stringing.The signal transmission-stable combined power supply vehicle comprises a power supply equipment main body, wherein a support platform is arranged at the bottom of the power supply equipment main body, two guide grooves extending from front to back are formed in the top of the support platform, the interiors of the two guide grooves are slidably connected with guide blocks, and the bottoms of thetwo guide blocks are fixedly connected with the bottom of the power supply equipment main body. When the scheme is used, after the whole equipment is moved to a designated position through mutual cooperation of the supporting legs and the walking wheels, supporting and positioning are carried out through the vehicle body stabilizing assembly, so that the working stability of the power supply equipment main body is improved, convenience is brought to movement, stable work is achieved, and the working quality is improved; and through the mutual cooperation of the guide grooves, the guide blocksand the positioning assembly, the fine adjustment of the power supply equipment can be quickly and stably realized, then the signal transmission is quickly and stably carried out, and the work efficiency is improved.

The invention discloses a cable laying device, and belongs to the field of electric power engineering equipment. A cable laying support is horizontally and fixedly arranged on the upper side of a cable laying base, a laying positioning mechanism is arranged on the cable laying support along the lower portion of the side of a cable conveying guide roller, the cable conveying guide roller is horizontally and rotationally connected to one side of the upper portion of the cable laying support, and a reciprocating translation guide plate is arranged on a cable pulling and conveying guide rod in a sliding mode in the horizontal direction. The upper pulling and conveying pressing plate is horizontally arranged on the upper side of the lower pulling and conveying bearing plate, a translation pushing wedge plate is horizontally and fixedly arranged on the upper pulling and conveying pressing plate along the cable clamping mechanism side, and the cable clamping pressing plate is horizontally arranged on the upper side of the cable laying guide roller. And the cable clamping pressing plate is horizontally and fixedly provided with a bearing and pushing lifting wedge plate matched with the translation pushing wedge plate along the cable pulling and conveying mechanism side. The cable laying device is reasonable in structural design and stable in operation and use, cables can be efficiently and smoothly pulled and laid section by section, the automation degree of cable laying is improved, and the use requirement is met.

The invention discloses a hoisting tool and hoisting method of a hydraulic submersible pump, belonging to the field of ship liquid cargo loading and unloading systems. The power transmission pipe of the hydraulic submersible pump is divided into a first transmission pipe and a second transmission pipe. The hoisting plate connects the first flange and the second flange on the first transfer pipe to hoist the first transfer pipe into the liquid cargo tank. The first flange and the second flange are interposed between the hoisting plate and the first support plate, realizing the support positioning of the first support plate and the second support plate on the deck of the first flange and the second flange, Ensure that the position of the first transfer pipe is installed accurately. The lifting plate is removed, the second transmission pipe is hoisted, and the second transmission pipe is connected to the first flange and the second flange through the connection space between the first support plate and the second support plate. Remove the first support plate and the second support plate, lift the second transfer pipe into the liquid cargo tank and fix the second transfer pipe and the deck. Ensure that the hydraulic submersible pump is hoisted in sections to reduce the bending problem caused by the shaking of the power transmission pipe when it is too long.

The invention provides a crankshaft transfer frame box comprising a pedestal, stand pillars, a reinforced top plate, grooved stand plates, fixed separating plates, movable separating plates and supporting plates. The pedestal is formed by welding cross connecting plates and longitudinal connecting plates. The two grooved stand plates are vertically fixed between the cross connecting plate on the left side and the reinforced top plate; the movable separating plates are installed in layers; two movable separating plates in each layer are movably connected with the grooved stand plates via hinge shafts and are supported on the grooved stand plates, with the right ends being supported by the supporting plates; the supporting plates are arranged between the two stand pillars on the right side in layers; push-pull rods penetrating the grooved stand plates transversely are arranged between the stand pillars on the left side in layers; the push-pull rods are provided with insertion pins which are located above the hinge shafts on the grooved stand plates and are corresponding to insertion pin holes in the grooved stand plates and the movable separating plates so as to locate the movable separating plates which are turned to stand in an inclined manner. The crankshaft transfer frame box is reasonable in structure, facilitates crankshaft loading and unloading operations, is high in carrying efficiency and is suitable for carrying of various kinds of crankshafts.

The invention discloses a flaw detection device used for the welding seam of a saddle groove partition plate, belonging to the field of flaw detection devices. The flaw detection device includes a bracket, a walking module, a positioning module, an adjusting module and a probe. The walking module is installed at the bottom of the bracket, and the top of the bracket is provided with a support column, which is arranged horizontally. The positioning module is slidably set on the support column, and the positioning An elastic piece is arranged between the module and the support column, one end of the elastic piece is connected to the positioning module, the other end of the elastic piece is connected to the support column, the adjustment module is slidably installed on the positioning module, and the probe is rotatably installed on the adjustment module. The invention can realize the flaw detection of the weld seam of the saddle groove diaphragm.

The invention discloses a booster opening mechanism of a gearbox control assembly. The booster opening mechanism of the gearbox control assembly comprises an input gear shifting lever, a booster inputpoking head, a booster input shaft, a booster output shaft, a booster output poking head and an output gear shifting lever. One end of the input gear shifting lever stretches into a control assemblyshell and is fixedly connected with one end of the booster input poking head, the other end of the booster input poking head is connected with the booster input shaft, the other end of the booster input shaft is located inside the booster output shaft, and the booster input shaft is connected with a booster valve element. The outer wall of the booster output shaft is connected with the booster output poking head and the output gear shifting lever in sequence. When the booster input shaft moves, the booster valve element is opened, and the booster output shaft is pushed to move in the movementdirection of the booster input shaft. According to the booster opening mechanism of the gearbox control assembly, a booster opening structure which is of an internal and external shaft structure and is located on the control assembly is replaced by a two-section type booster opening structure, the single-lever and dual-lever universal control is replaced by the dual-lever control, and therefore the structure of the control assembly is greatly simplified, the cost is reduced, and the gear selection performance of the control assembly is improved.

The invention discloses a discharging door of a vertical shaft stirrer, and belongs to the technical field of concrete stirring. The discharging door comprises a discharging door body and a discharging door seat, and is characterized in that the discharging door further comprises a fixed seat, a discharging door shaft, a bearing, a flat key and a gland nut; the discharging door shaft is mounted inthe discharging door seat through the bearing; a threaded lead screw is arranged at the top end of the discharging door shaft; the top end of the discharging door shaft is in threaded connection withthe fixed seat; the fixed seat is fixed to the discharging door seat; the discharging door body is connected with the discharging door shaft through the flat key and is fixed to the discharging doorshaft through the gland nut; a discharging door sealant is arranged on the discharging door body; and a tank body sealant is arranged on a tank body. According to the discharging door, after rotary lifting is adopted for compensating for sealing, the sizes of clearances between the discharging door and the tank body sealant and between the tank body and the discharging door sealant are adjusted automatically, and automatic sealing compensation of the discharging door is achieved; and after being closed, the discharging door is in the tightest compression sealing state, sealing is achieved moretightly, and slurry leaking is not prone to happening to the tank body.

The invention provides a photoelectric composite cable which comprises an outer sheath and a cable core arranged in the outer sheath. The cable core comprises an optical fiber bushing, copper conductors, a filler rope and cable paste, wherein the optical fiber bushing, the copper conductors and the filler rope are arranged in a spaced mode; the cable paste is filled among the optical fiber bushing, the copper conductors and the filler rope. A steel belt longitudinal wrap with which the outer circumferential face of the cable core is coated is arranged in the outer sheath, and reinforcers which extend in parallel with the cable core are arranged in the wall of the outer sheath. Compared with the structure that the reinforcers are arranged in the center of the cable core in the prior art, the photoelectric composite cable has the advantages that the reinforcers are arranged in the wall of the outer sheath, the radial dimension of the wall of the outer sheath is effectively utilized, space is not additionally occupied, the outer diameter of the cable core can be effectively reduced on the premise that tensile strength of the composite cable is guaranteed, and accordingly cost of the cable paste filled into the cable core can be lowered and the outer diameter dimension of the whole cable core can be reduced; the cable core is coated with the steel belt longitudinal wrap, so strength of the whole cable core can be effectively improved, and the cable core of the cable can be better protected.

The invention aims to solve the problem of gall bladder resection, and discloses a gall bladder extractor for gall bladder resection surgery. The gall bladder extractor comprises a cover tube, wherein a tray is fixedly mounted at the right end of the cover tube, a sucker is fixedly mounted on the right end surface of the tray, a positioning ring is fixedly mounted on the front side surface of the cover tube, a catheter communicated with the tray is sleeved in the positioning ring, an air bag is fixedly installed at the left end of the catheter, a connector is arranged on the air bag, a supporting rod is fixedly installed on the right side of the upper surface of the cover pipe, a rotating block is installed at the top end of the supporting rod, a movable shaft is installed between the rotating block and the supporting rod, a sleeve is fixedly installed on the upper surface of the rotating block, an insertion pipe is sleeved with the sleeve, a positioning block is fixedly arranged on the right side in the cover pipe in a sleeved mode, and an inserting needle is arranged in the positioning block in a sleeved mode. According to the invention, the inserting needle is inserted into the gall bladder, and bile in the gall bladder is extracted out, so that the bile is prevented from flowing into a human body when the gall bladder is cut, and the human body is better protected.

The invention relates to the technical field of ship instruments, and discloses an adjustable skiff storage tool. The storage tool comprises a base, wherein a supporting frame used for laterally supporting skiffs is arranged on the base, the supporting frame comprises two supporting pieces rotationally assembled on the base and a driving piece driving the supporting pieces to rotate, the two supporting pieces are arranged in a V shape, and a containing space used for containing the skiffs is formed between the two supporting pieces. According to the adjustable skiff storage tool, when the skiffs of different types are stored, an operator can arrange the skiffs in the containing space between the two supporting pieces, the driving piece drives the supporting pieces to rotate on the base tochange the included angles between the supporting pieces and the base so that the size of the containing space can be changed, the two supporting pieces make lateral contact with the skiffs to supportthe skiffs so as to avoid rollover of the skiffs, and supporting and positioning of the skiffs of different types are realized, so that manufacturing of different types of supporting tools is avoided, storage cost of the skiffs is reduced, the process of adjusting posture of the skiffs is also omitted, and therefore storage efficiency is improved.

The invention belongs to the field of graphitized internal series furnaces, and discloses a combined electric trolley for graphitized internal series furnaces with stable signal transmission, including a main body of power transmission equipment, a support platform is set at the bottom of the main body of the power transmission equipment, and the support platform The top is provided with two guide grooves extending from front to back, the insides of the two guide grooves are slidingly connected with guide blocks, and the bottoms of the two guide blocks are respectively fixedly connected with the bottom of the main body of the power transmission device. When this solution is used, the entire device is moved to the designated position through the mutual cooperation of the supporting legs and the walking wheels, and then supported and positioned by the vehicle body stabilization component, thereby increasing the stability of the main body of the power transmission device when it is working, and realizing easy movement Taking into account stable work and improving work quality, through the mutual cooperation of guide grooves, guide blocks and positioning components, the fine-tuning of power transmission equipment can be realized quickly and stably, and then the signal transmission can be carried out quickly and stably to improve work efficiency.

An assembly type suspended ceiling vertical plate hanging installation structure comprises a vertical frame plate and a keel arranged on the vertical frame plate, a hanging strip connected with the keel is arranged on the vertical frame plate, and the vertical frame plate comprises a long edge and a short edge which are connected. Corresponding keel hanging pieces are arranged at the bottoms of the keels, the hanging strips penetrate through the keel hanging pieces, and frame connecting pieces connected with the keel hanging pieces are arranged on the long edges of the hanging strips. Vertical frame hanging pieces are arranged on the short edges, and leveling pieces are arranged on the vertical frame hanging pieces and the keels; compared with the prior art; the vertical frame plates and the hanging strips are supported and positioned in the vertical direction through connection between the vertical frame plates and the frame-shaped clamping pieces and insertion connection between the hanging strips and the frame-shaped clamping pieces, meanwhile, the keel hanging pieces are hung at the bottoms of the keels, and through insertion connection between the hanging strips and the keel hanging pieces, the vertical frame plates and the hanging strips are supported and positioned in the vertical direction. The overall vertical frame plate and the keel are supported and positioned in the vertical direction, the overall structure is simple, and disassembly and assembly are convenient and fast.