660 results about "Dead weight" patented technology

The invention discloses a high and large formwork engineering supporting system construction method, and belongs to the technical field of building engineering. Comprising the following steps: step 1, arranging intelligent nodes in a high and large template support system to realize information sharing and group cooperative regulation and control among the nodes; step 2, dividing the support system into a plurality of mutually associated load control areas, and setting differentiated load control parameters; step 3, automatically optimizing a pouring path; 4, when the concrete strength reaches a preset threshold value, the supporting rigidity or the reserved deformation amount is automatically adjusted according to a preset program, and the concrete structure bears the dead weight step by step; 5, the temporary load is automatically compensated, when the load exceeds a safety threshold value, a load redistribution mechanism and a reinforcing device are triggered, meanwhile, an alarm is started, and abnormal data are pushed; and step 6, continuously optimizing control parameters, accumulating construction data, constructing a digital construction record and a knowledge base, and realizing intelligent iterative upgrading of the construction method.

The invention discloses an electromagnetically-supported hybrid magnetic thrust bearing structure and a suspension force design method, and provides a hybrid magnetic bearing structure design in which radial alternate magnetization is adopted in the axial direction, a permanent magnet bearing formed by stacking multiple layers of magnetic rings bears all axial thrust loads, and radial electromagnetic bearings are assisted at the two ends to maintain dynamic stability of a rotor. The performance requirements of high bearing capacity, low power consumption, good active control capability and high dynamic stability of the hybrid magnetic thrust bearing in a limited space are met; in order to solve the problems that an inner magnetic ring and an outer magnetic ring are not strictly centered due to the influence of machining precision, an assembly process, rotor eccentricity and the like during actual operation of a permanent magnet thrust bearing, additional unbalance load, dynamic unbalance load and the like are generated in the radial direction. The electromagnetic supporting suspension force design method comprehensively considers the radial unbalance load of the permanent magnet thrust bearing, the dynamic unbalance load of the rotor and the self-weight influence, effective calculation of the suspension force of the supporting rotor is achieved, and important technical support is provided for the hybrid magnetic thrust bearing structure and suspension force design iteration.

The invention discloses a method for calculating stress and deformation of a roller carrier supporting thin-walled cylinder under the action of dead weight, which comprises the following specific steps of: S1, calculating the bending moment and deflection of a cylinder body in the longitudinal direction by adopting an overhanging beam model in the longitudinal direction, and determining the optimal position of the roller carrier in the longitudinal direction according to the maximum bending moment minimization and the maximum deflection minimization of a beam; s2, transversely utilizing symmetry to establish a semicircular curved beam model, and calculating bending moment and displacement in a transverse plane of the cylinder by adopting a Temosinke beam theory; s3, calculating the maximum stress in the cylindrical surface according to the in-surface bending moment, and determining the optimal half wrap angle required by the strength; and S4, calculating the ovality and root-mean-square roundness of the curved beam according to the displacement, and determining the optimal half wrap angle required by deformation. According to the method, the maximum stress and the deformation shape of the thin-walled cylinder are accurately predicted, and the optimal wrap angles of the roller carrier under the strength requirement and the deformation requirement can be determined to be 67.4 degrees and 90 degrees respectively, so that the optimal wrap angle is suggested to be between 67.4 degrees and 90 degrees in engineering.

A positioning device for H-shaped steel cutting machining comprises a supporting piece, a positioning piece and a positioning piece, a through containing groove is formed in the supporting piece, and the supporting piece is used for containing H-shaped steel and making the H-shaped steel in a suspended state; the two sets of positioning pieces are symmetrically arranged on the left side and the right side of the first end opening penetrating through the containing groove, located in the thickness direction of a web of the H-shaped steel and used for conducting preliminary extrusion positioning on the web of the H-shaped steel; the two sets of fixing pieces are symmetrically arranged on the upper side and the lower side of a first port penetrating through the containing groove, located in the height direction of a web of the H-shaped steel and used for being matched with the thickness of the web of the H-shaped steel and fixing the H-shaped steel in a suspended mode; and the two sets of guiding pieces are symmetrically arranged on the left side and the right side of the second end opening penetrating through the containing groove, located in the thickness direction of a web of the H-shaped steel and used for conducting suspension guiding on the H-shaped steel by abutting against the two sides of the web of the H-shaped steel. The device mainly can reinforce suspended H-shaped steel, the clamping stability of the H-shaped steel is guaranteed, and the probability that due to the fact that deviation is likely to happen under the influence of the dead weight of steel, a notch inclines or the size is out of tolerance is effectively reduced.

The utility model relates to the technical field of riprap fixing equipment, in particular to a riprap fixing device which comprises a riprap frame and a stretching net bag, the stretching net bag is arranged at the bottom of the riprap frame, the riprap frame and the stretching net bag are of a trapezoidal cage-shaped structure, the riprap frame is of a hollow structure, and a riprap opening is formed in the riprap frame. The stretching net bag is used for wrapping the submarine cable, and based on the principle of a riprap protection method, stone blocks are placed around the suspended submarine cable to fill the space, and a proper shape is built to protect the submarine cable; the device is filled with stones, the lower stretching net bag wraps the submarine cable under the action of gravity, and the suspended submarine cable is tightly surrounded by the device and the stones, so that the suspended submarine cable does not move any more, loss is reduced, the phenomenon that the suspended submarine cable is flushed down by water flow is avoided, and the dead weight and the structure of the device can ensure that the device is fixed in ocean current for a long time; and protection can be carried out for a long time, and the cost and the subsequent maintenance cost are saved.

The utility model provides an active dynamic balancing device based on a tower crane. The active dynamic balancing device comprises a tower body, a working arm and a balancing arm, wherein the working arm and the balancing arm are fixedly mounted on two sides of the top of the tower body respectively; a water storage tank and a balance water tank are fixedly mounted on the balance arm, and the bottom of the water storage tank is communicated with the balance water tank through a connecting pipeline; and a control valve group for controlling water distribution between the water storage tank and the balance water tank is arranged on the connecting pipeline. According to the utility model, the balance weight of the balance arm is designed into the capacity-adjustable water tank, the working moment is balanced by utilizing the moment generated by the dead weight of the water body, the volume of the balanced water body is adjusted in real time according to requirements, so that the moment is changed, and the quantity of the water body distributed in the water storage tank and the balanced water tank is adjusted in real time according to the working moment. And the balance moment is synchronously equal to the working moment in real time.

The invention relates to a pressing device, crimping equipment and a control method, the pressing device comprises a fixed seat, a pressing head structure, a pressing driver and a lifting driver, and the pressing head structure is movably arranged on the fixed seat; the press-fit driver is arranged on the fixed seat and connected with the pressure head structure so as to drive the pressure head structure to perform press-fit motion; the lifting driver is arranged on the fixed seat, the lifting driver is connected with the pressing head structure, and when the pressing device is in a working state, the lifting driver is used for lifting the pressing head structure in the direction opposite to the gravity direction so as to balance the dead weight of the pressing head structure. The lifting driver can lift the pressure head structure and balance the dead weight of the pressure head structure. Therefore, when the pressing driver drives the pressing head structure to perform pressing motion, the weight load of the pressing head structure does not need to be considered, so that higher-precision position control can be achieved when the pressing driver drives the pressing head structure to move, and higher-precision pressure can be output when the pressing device performs pressing operation so as to meet the pressing requirement.

The invention discloses a tractor chassis forging and drawing device and relates to the technical field of high-horsepower tractor production, the tractor chassis forging and drawing device comprises a machine base and a supporting assembly, a mold is arranged at one end of the top of the machine base, a chain conveyor is arranged in the machine base, a moving trolley is connected to the top of the machine base, and a clamp is arranged at the top of the moving trolley; the supporting assembly is connected to one side of the moving trolley and comprises a driving plate. Automatic lifting of the supporting mechanism is achieved through magnetic attraction linkage, when the moving trolley is away from the mold, a magnet drives a sliding block to drive a guide base to move, a sliding column ascends to a transverse groove along an inclined groove to be locked, a supporting rod pushes a pulley to make contact with the bottom of a bar to form supporting, and a suspended section between a mold outlet and a clamping point is effectively eliminated through the design; and stress field deviation caused by bending moment generated by the dead weight of the bar is avoided, the pulley structure provides stable bearing and can reduce surface scratches, and the drawing process quality is remarkably improved.

The application relates to a device and method suitable for precise positioning of steel pull rods of arch feet of steel truss arch bridges, the device comprising a first positioning steel plate and a second positioning steel plate, the length of the steel pull rod in the concrete arch support foundation being L, L being divided into n sections, the first positioning steel plate being arranged at a starting point node, the second positioning steel plate being arranged at intermediate nodes, and a lower bearing plate being arranged at an end point node, a plurality of through holes being arranged on the first positioning steel plate and the second positioning steel plate, the through holes being used for the steel pull rod to pass through, the positions of the first positioning steel plate and the second positioning steel plate being fixed through four coordinates, steel frame structures being arranged between the first positioning steel plate and the second positioning steel plate, adjacent second positioning steel plates, the second positioning steel plates and the lower bearing plate, and the steel frame structures being welded with the first positioning steel plate and the second positioning steel plate. The application can position the steel pull rod, avoid the steel pull rod from being deflected under the dead weight or being deformed under the impact of concrete pouring, and ensure that the long steel pull rod is perpendicular to the upper and lower bearing plates during construction.

The invention relates to a truss-rib-free laminated slab and a string truss supporting device thereof, and belongs to the technical field of building structure engineering.The laminated slab comprises a prefabricated bottom plate, Y-shaped shear keys, concrete ribbed beams and ribbed bolt sleeves, traditional truss steel bars are omitted, innovative construction of the Y-shaped shear keys and the ribbed bolt sleeves is adopted, the steel consumption is remarkably reduced, and the cost is reduced. And meanwhile, pre-arching control over the prefabricated bottom plate is achieved through the string truss supporting device, and the construction efficiency and the environmental protection performance are improved. The device is designed to be three-point supporting or four-point supporting according to the span of the prefabricated bottom plate, is rapidly assembled through bolts and can be repeatedly used, and the construction cost is reduced. On the premise that the bearing performance of the structure is guaranteed, steel is saved by about 20%, the dead weight of the structure is reduced, the construction efficiency is improved, and green construction and sustainable development are achieved.

The invention relates to the technical field of hydrological monitoring, and discloses a hydrological information observation and monitoring unmanned ship which comprises a ship body, a multi-parameter water quality instrument and a cabin formed in the top of the ship body, a mounting frame is fixedly mounted on the top surface of the ship body, and a laser radar and a monitoring camera are mounted at the top of the mounting frame through bolts; according to the hydrological information observation and monitoring unmanned ship, the immersion depth can be increased by increasing the self weight in the using process, the stability of the ship body is improved, the supporting face between the ship body and the water surface is enlarged in the self weight increasing process of the ship body, and the stability of the ship body is further improved; therefore, stable and effective hydrological monitoring is guaranteed, the accuracy of hydrological monitoring data is improved, and when transfer is needed, the increased dead weight and the enlarged supporting surface are reduced, so that the advancing resistance of the ship body is reduced, the advancing maneuverability of the ship body is improved, and the working efficiency of hydrological monitoring is improved. Effective coordination of stability and maneuverability of the unmanned ship is realized.

The invention belongs to the technical field of bridge engineering earthquake resistance, and particularly relates to a bridge bidirectional self-resetting earthquake-resistant device and method with a multistage earthquake-resistant function, the bridge bidirectional self-resetting earthquake-resistant device comprises an upper sliding cover plate and a lower fixing base, the upper sliding cover plate is provided with a convex block, the lower fixing base is provided with a groove, and the convex block is in sliding connection with the groove; when the support is normally used and the earthquake force is smaller than the elastic deformation force of the plate-type rubber support, the support is normally used through the shape of the plate-type rubber support, and when the earthquake force is larger than the elastic deformation force of the plate-type rubber support, the upper sliding cover plate and the lower fixing base slide relatively. When the earthquake force is continuously increased, the inclination angle formed by the protruding block of the upper sliding cover plate and the groove of the lower fixing base is used for resisting the earthquake force, and self-resetting of the main beam is achieved through the self-weight effect. A support sliding shock insulation mechanism is fully utilized, serious damage to bridge piers after an earthquake is avoided, meanwhile, residual displacement of the bridge after longitudinal and transverse earthquakes is reduced, beam falling is avoided, and the shock resistance toughness of the bridge under a large earthquake is improved.

The invention relates to the technical field of metal plastic forming, and provides a precision control system and method for bending forming of a long cylinder section wall plate of a storage box. The electric feeding table is arranged on the front side of the numerical control bending press; the follow-up material supporting device is arranged on the rear side of the numerical control bending machine and can support the bent arc section of the wallboard; and the machine vision camera is arranged on the side surface of the numerical control bending press and is matched with the control device to carry out online detection. Automatic feeding can be accurately controlled in the long cylinder section wallboard bending forming process, the follow-up material supporting device can adjust the position of an electric swing supporting arm and the angle of a swing arm at any time, the influence of the dead weight of a bent arc section wallboard on the forming curvature is counteracted, online detection is conducted on the curvature of an area inner wallboard through the machine vision technology, and the forming accuracy is improved. The bending forming precision of the long cylinder section wall plate of the storage box is greatly improved, and the detection efficiency is greatly improved.

The invention belongs to the field of building prefabricated slabs, and particularly relates to a light-weight prefabricated laminated slab which comprises an inverted-T-shaped concrete prefabricated slab formed by pouring aerated concrete. Truss rib mechanisms are arranged in the concrete prefabricated slabs, the multiple concrete prefabricated slabs are tightly attached to form a prefabricated base, reinforcement cage parts are longitudinally arranged at the concave positions between the adjacent concrete prefabricated slabs on the prefabricated base, and triangular cone parts are arranged in all triangular rib structures located at the same transverse position on the prefabricated base in a penetrating mode. The triangular cone parts synchronously penetrate through the middle parts of all the reinforcement cage parts at the same transverse position; aerated concrete is adopted as a main body material of the prefabricated slab, the dead weight of the floor slab is remarkably reduced, and meanwhile the concrete consumption is reduced through the inverted-T-shaped structural design; the composite structure of the truss rib mechanism, the reinforcement cage part and the triangular cone part optimizes the use amount of reinforcing steel bars on the premise of ensuring the strength, so that materials are saved.

The invention relates to the technical field of sealant packaging equipment, in particular to an automatic sealant production line which comprises a bag sealing mechanism. The bag sealing mechanism comprises a frame body, an unwinding assembly is arranged at the top of the frame body and comprises a shear fork arm assembly and a driving motor, carrier rollers are symmetrically installed at the two ends of the top of the shear fork arm assembly, and an auxiliary synchronous belt wheel is fixed to one end of one carrier roller; a third rotating shaft is arranged at the intersection point position of the shear fork arm assembly, one end of the third rotating shaft is fixedly connected with the output end of the driving motor through a coupler, and a main synchronous belt wheel in driving connection with the auxiliary synchronous belt wheel is fixed to the other end of the third rotating shaft; a first rotating shaft in sliding fit with the upper side plates on the two sides is arranged at one end of the bottom of the shear-fork arm assembly, and a second rotating shaft is arranged at the other end of the bottom of the shear-fork arm assembly and rotationally connected with the upper side plates on the two sides. The distance between the carrier rollers changes synchronously in real time along with the dead weight of the film roll and is matched with the dead weight of the film roll all the time, and dynamic and accurate adaptation in the full-unwinding process is achieved.

The invention discloses a construction method for repairing a concrete bridge deck through PVC pipes and a bridge deck structure thereof.The construction method for repairing the concrete bridge deck through the PVC pipes comprises the steps of early-stage calculation, broken bridge deck chiseling away, PVC pipe laying, concrete pouring and the like, and on the premise that it is guaranteed that the overall load of the bridge deck after maintenance and reinforcement meets the design requirement of an original bridge, the overall load of the bridge deck is reduced; the construction period is shortened and the construction cost is reduced while bridge deck maintenance and reinforcement are realized. A bridge deck structure repaired through PVC pipes comprises an original bridge deck pavement retaining layer and a concrete overlay layer, and the dead weight of a newly-added structure can be effectively reduced while the structural strength is guaranteed. The PVC pipe is applied to the maintenance and reinforcement engineering of the concrete bridge floor, the construction period of bridge floor maintenance is shortened while the cost is reduced, and the service life of a bridge is prolonged.

The invention provides a high-precision calculation method for weighing a farm feed tower under a wind load condition, and belongs to the technical field of weight calculation methods. The method specifically comprises the following steps that the dead weight of a feed tower, the total weight after feed is added and the static supporting force of each supporting leg are determined; the wind direction is measured, and the supporting legs are divided into a windward group and a leeward group according to the vertical symmetry plane, perpendicular to the wind direction, of the center of the material tower; respectively calculating the vertical distance from each supporting leg of the windward group and the leeward group to the symmetry plane, calculating the wind load force and the upsetting moment by combining the wind speed to establish a supporting leg counter-force mathematical model under the wind load, and obtaining the dynamic supporting force of each supporting leg; superposing the static supporting force and the dynamic supporting force of each supporting leg to obtain an estimated supporting force of each supporting leg; the estimated supporting force of each supporting leg under the wind load and the supporting force, measured in real time, of each supporting leg are used for conducting filtering calculation to obtain accurate dynamic supporting force of the wind load; and deducting the accurate wind load dynamic supporting force and the dead weight of the feed tower to obtain the actual accurate weight of the feed.

The invention relates to the technical field of valve welding, in particular to a valve body welding positioning tool which comprises a supporting assembly used for containing a valve body, an inner positioning assembly for positioning the inner side of the valve body and an outer positioning assembly for positioning the outer side of the valve body are arranged on the supporting assembly, and a pressing assembly corresponding to the valve body is arranged on the supporting assembly; the pressing assembly is pressed downwards through the dead weight of the valve body, the inner positioning assembly and the outer positioning assembly are synchronously driven to move towards the center of the valve body, radial accurate positioning of the valve body is achieved through inner and outer side extrusion, manual repeated position adjustment is avoided, and measurement errors are eliminated. And meanwhile, when the transmission assembly moves in the inner positioning assembly and the outer positioning assembly, the support conveying assembly is hydraulically driven, the valve body supports are extruded to the outer sides of the valve bodies, automatic alignment before welding is achieved, positioning of the two valve body supports can be synchronously completed, and efficiency is improved.

The invention provides a semi-automatic protective net shed for an orchard. The semi-automatic protective net shed comprises a shed frame; the protective net is used for enclosing the shed frame; the multiple winding mechanisms are used for winding the protective net, and each winding mechanism comprises a winding roller connected with the winding end of the protective net; the driving part is used for driving the winding roller to rotate; the winding ropes are located at the two ends of the winding roller in the length direction, one end of each winding rope is fixedly connected with the winding roller, and the other end of each winding rope is connected with the top of the shed frame; and the guide part is used for guiding the driving part to move on a preset track. According to the invention, the weight of the winding roller and the driving part is more borne by the winding rope, so that the protective net does not need to be torn off; when the winding roller rotates reversely to wind the lower winding rope, the winding roller can be pulled down under the dead weight of the winding roller and the driving component, the situation that the protective net cannot be opened is avoided, use is convenient, cost and labor employment are reduced, and safety and reliability are achieved.

The invention discloses a cavity assembly type reinforced concrete web bridge structure and a construction method thereof, and relates to the technical field of bridge engineering.The cavity assembly type reinforced concrete web bridge structure comprises a plurality of cavity type webs arranged in the length direction of a bridge, the upper side and the lower side of the web center component are each provided with a steel bar staggered net composed of a plurality of oblique steel bars and a plurality of transverse steel bar rings, and the steel bar staggered nets are in a hollow frustum shape. The top flange steel plate is horizontally arranged at the top of the cavity type web, and a concrete bridge deck is arranged at the top of the top flange steel plate; the lower flange steel plate is horizontally arranged at the bottom of the cavity type web; according to the hollow cavity type web, the inclined steel bars, the transverse steel bar rings and the web center component are combined to form a hollow frustum structure, the dead weight of a web bridge structure is greatly reduced, stress concentration is avoided, the cracking risk of the structure is reduced, and the overall strength and stability of the structure are effectively enhanced; meanwhile, local shear resistance and bending resistance are enhanced, the service life of the bridge is prolonged, and the probability of local damage is reduced.

The utility model discloses a composite aircraft integrating coaxial multi-rotor wings and tilting multi-rotor wings. The composite aircraft comprises an aircraft body, a hollow supporting column, at least two main lift force rotor wing assemblies and at least two tilting rotor wing assemblies. The lower end of the hollow supporting column is arranged on the upper surface of the machine body. A load is installed at the upper end of the hollow supporting column. According to the main lift rotor assembly, a first motor is installed on a hollow supporting column, the hollow supporting column is sleeved with a main lift rotor, and the first motor is connected with the main lift rotor; according to the tilting rotor assembly, an output shaft of a steering engine is connected with one end of a rotating shaft; a second motor is mounted at the other end of the rotating shaft and is connected with the tilting rotor; the steering engine is mounted on the fuselage, so that the rotating shafts extend outwards from the side surface of the fuselage, and the included angles between any two adjacent rotating shafts are the same; the size of the main lift rotor is larger than that of the tilting rotors, so that the tilting rotors are all located under the main lift rotor. The scheme is high in hovering and low-speed flight efficiency, low in noise and small in dead weight.

The utility model discloses a floating roller device and a tension control mechanism, the floating roller device comprises a main wall plate, a floating roller mounting main plate, a floating roller driving mechanism, a floating roller body and a counterweight assembly, the floating roller mounting main plate is rotatably mounted on the main wall plate, the floating roller driving mechanism drives the floating roller mounting main plate to rotate, and the counterweight assembly drives the floating roller body to rotate; the end of the floating roller body is installed on one side of the rotating center of the floating roller installation main plate, and the balance weight assembly is arranged on the other side of the rotating center of the floating roller installation main plate. According to the floating roller device, the influence of the dead weight of the floating roller can be reduced, the tension adjusting precision is improved, and the tension adjusting effect is improved. The overall tension adjusting structure formed based on the floating roller device can effectively and accurately control tension, and the corresponding production effect and product quality are improved.

The utility model provides a counterweight combined support, and relates to the technical field of elevator accessories, the counterweight combined support comprises a counterweight transverse support, counterweight vertical supports are connected to the two ends of the counterweight transverse support, first connecting pieces are arranged at the joints of the counterweight vertical supports and the counterweight transverse support, and the first connecting pieces are detachably connected with the counterweight vertical supports and the counterweight transverse support; and the counterweight vertical bracket and the counterweight transverse bracket are formed by punching. The counterweight vertical support and the counterweight transverse support are both formed through punching, the bending strength of the cross section is increased through machining, compared with a traditional support, more materials are saved, the production cost is reduced, on the premise that the strength is guaranteed, the dead weight of the support is reduced, the workload of installation personnel is effectively relieved, the space occupancy rate is lower, and the service life of the support is prolonged. The space utilization rate of an elevator shaft can be increased; all the components are connected and fixed through bolts, the adjusting difficulty of the support is lowered, and the adjusting range for irregular well wall faces is greatly widened.

The utility model discloses a combined photovoltaic support which comprises a first base which is driven into the ground below the head of a bearing plate, the upper surface of the first base is provided with a first supporting pipe, the top of the first supporting pipe is provided with a first hinged support, and the lower surface of the head of the bearing plate is provided with a hinged shaft hinged to the first hinged support; the second base is driven into the ground below the head of the bearing plate, a second supporting pipe is arranged on the upper surface, and an outer sleeve slidably sleeves the outer side of the top of the second supporting pipe; a first opposite-pull hole is formed in the pipe wall of the second supporting pipe, and a second opposite-pull hole is formed in the wall of the outer sleeve; the supporting rod is arranged at the top of the second supporting pipe, a second hinge support is arranged at the top of the supporting rod, a rotating block is hinged into the second hinge support, a sliding groove is formed in the rotating block, and a sliding rod is arranged on the bearing plate. The height of the tail part of the bearing plate is adjusted by matching the outer sleeve with the second base, so that the angle of the bearing plate is adjusted, the structure of the tracking type photovoltaic bracket can be effectively simplified, the overall dead weight of the device is reduced, and the requirement on the ground bearing capacity is reduced.

The utility model provides a building truss structure which comprises four vertical rods in one group, the outer sides of the bottom ends of the vertical rods are fixedly connected through a first cross rod, the outer sides of the top ends of the vertical rods are fixedly connected through a second cross rod and a third cross rod, and positioning columns are fixedly sleeved with the top ends of the vertical rods. According to the building truss structure, through cooperative use of the vertical rods, the first cross rods, the second cross rods, the third cross rods and the positioning columns, the truss structure can be assembled through a plurality of independent assemblies of the same structure, and then the size and the self weight of the single assemblies are small, so that carrying and assembling are facilitated; by rotating a bidirectional screw rod, a first limiting plate and a second limiting plate can be driven to reversely move in the axial direction of a third cross rod, and meanwhile, the first limiting plate and the second limiting plate are clamped to the outer side of a limiting block, so that the single assemblies which are assembled up and down are quickly limited and fixed; therefore, the truss structure can be disassembled and assembled conveniently.

The invention discloses a cavity leveling layer structure suitable for bridge longitudinal section transformation and a construction method thereof, belongs to the field of bridge engineering, and solves the problem that the dead weight of a box girder can be increased by adding a concrete leveling layer. The device comprises a box girder, a concrete leveling layer is arranged at the top of the box girder, and a plurality of hollow pipes are arranged in the concrete leveling layer side by side. The construction method comprises the following steps: cleaning sundries on the surface of the box girder structure to completely expose the top surface of the box girder; chiseling a notch in the top surface of the box girder, wherein the depth of the notch is based on the exposure of box girder steel bars; the vertical steel bars and the box girder steel bars are welded, and the notches are filled; longitudinal steel bars and transverse steel bars located on the lower portion of the concrete leveling layer are bound and fixed through vertical steel bars; hollow pipes are installed, and the hollow pipes are laid between the vertical steel bars; longitudinal steel bars and transverse steel bars located on the upper portion of the concrete leveling layer are bound and fixed through vertical steel bars; and pouring a concrete leveling layer. The self weight of the structure is effectively reduced.

The light-weight tire comprises a tire bead area, a tire side area, a tire body layer, a belted layer and a tire crown area which are distributed from inside to outside, the tire bead area is provided with a steel wire ring, bead filler wrapping the steel wire ring, a tire bead filling rubber strip covering the outer side of the bead filler, a wear-resistant rubber strip wrapping the exterior of a tire bead, and a tire chafer, the tire sidewall area comprises a tire sidewall and steel wire wrapping cloth at the edge of the tire sidewall, the tire body layer penetrates through the whole tire, the tire body layer comprises a tire body, and a lining layer is arranged on the inner side of the tire body layer. Through a series of structural design and process optimization measures, the self weight of the tire is reduced, and meanwhile, the driving performance and the safety of the tire are ensured not to be influenced.

The invention relates to the technical field of bridges, and provides a segment-assembled corrugated steel web mixed girder bridge and a construction method thereof.The areas, close to bridge piers, of side spans and middle spans are composed of first-class girder sections, and each first-class girder section comprises a first concrete top plate, a first concrete bottom plate and a first corrugated steel web; the midspan area is composed of a second type of beam sections and comprises a steel bottom plate, an ultra-high performance concrete combined top plate and a second corrugated steel web; and the combined beam section is connected between the two beam sections to realize smooth transition. Through the longitudinal partition structural design, the advantages of the respective materials are fully played, the side span-mid span ratio can be compressed to 0.35-0.60, and the span capacity is remarkably improved. An ultra-high-performance concrete combined top plate is adopted in the midspan, and the dead weight is reduced by 50%; the steel bottom plate is used for replacing a concrete bottom plate, and the cracking risk of the midspan bottom plate is thoroughly eliminated. Segmental prefabrication and assembly construction is adopted, the process is standardized, the adaptability to soft foundations is high, and the problems of midspan downwarping and web cracking are solved.

A prefabricated building foundation pit support template, including foundation pit and the side baffle that is arranged and set up along its inner wall both sides longitudinal arrangement, both sides side baffle outer wall near the center of foundation pit one side is equipped with side roof, and the bottom of two side roofs is equipped with the support platform for horizontally supporting, and is hung on the side baffle, so that side roof is suspended and is attached on the outer wall of side baffle, both sides side roof near the side of corresponding support platform is equipped with the hanging platform, and the inside of two hanging platforms is commonly equipped with the telescopic mechanism, because the utility model discloses the overall cooperation of support platform, hanging platform, telescopic mechanism, changes the three-step action of insertion- push top-limit into the traditional bolt connection, first, support platform bears the dead weight of side roof, hanging platform completes the quick hanging of side baffle, telescopic mechanism then synchronously tightens outwardly at one time, and the bolt is not repeatedly screwed on site, and a person can complete installation and removal, significantly shorten the support period, and the maintenance hidden danger caused by bolt corrosion and jamming is avoided.

The utility model discloses a tiltable power vertical take-off and landing unmanned aerial vehicle adopting a linked wing layout. The tiltable power vertical take-off and landing unmanned aerial vehicle comprises a fuselage, a pair of front wings, a pair of rear wings, a tail connecting wing and a side end connecting wing, the pair of front wings are respectively connected to two sides of the head of the fuselage; the pair of rear wings are respectively arranged on two sides above the rear part of the fuselage; the tail connecting wing is arranged on the upper side of the rear part of the fuselage and is respectively connected with the rear wings on the two sides; wingtips of the rear wings are connected with the front wings through the side end connecting wings. A front propeller is mounted on the lower side of each front wing, a lower hanging type mounting arm capable of tilting and adjusting in the front-back direction is arranged on the lower side of each rear wing, and a rear propeller is mounted at the tail end of the lower hanging type mounting arm. According to the utility model, the influence of the downward washing flow field of the front wing on the rear wing can be reduced, the lift-drag ratio of the rear wing is improved, the dead weight is reduced, and the cruising ability is improved.