178 results about "Curved beam" patented technology

The invention relates to the technical field of overhead line system cantilever installation, in particular to railway overhead line system cantilever installation equipment which comprises a hanging basket fixedly installed with an external climbing crane mechanical arm, an arc-shaped beam is slidably connected to the middle of the hanging basket in a clamped mode, and a first carrying plate and a second carrying plate are fixed to the two sides of the arc-shaped beam respectively. First motors used for driving the arc-shaped beam to rotate are fixed to the two sides of the hanging basket correspondingly, and two second motors are fixed to the top face of the first carrying plate. According to the invention, the motor II drives the poke rod to rotate, so that the inclined cantilever can be automatically inserted into the mounting hole of the lower insulator, and the motor I drives the arc-shaped beam to rotate upwards by taking the hinged position of the lower insulator and the supporting column as the circle center, so that the arc-shaped beam moves the flat cantilever to the position of the mounting hole of the upper insulator; and finally, the whole cantilever is pushed towards the supporting column through the poke rod again, the cantilever is automatically installed between the two insulators, and the cantilever installation efficiency can be improved.

The invention belongs to the technical field of vibration isolation, and particularly relates to a quasi-zero stiffness metamaterial sandwich structure, a vibration isolation device and a manufacturing method. The quasi-zero stiffness metamaterial sandwich structure is formed by periodically arranging unit cells in the horizontal direction, and each unit cell comprises an upper panel, a lower panel, a QZS resonator core body and a vertical supporting column; the QZS resonator core comprises a central mass block, QZS resonator units are arranged on the upper portion and the lower portion of the central mass block in a mirroring mode, each QZS resonator unit is composed of two quasi-zero-stiffness unit cells which are arranged in a crossed mode, and each quasi-zero-stiffness unit cell is composed of a negative-stiffness component comprising a horizontal curved beam and a positive-stiffness component comprising an oblique straight beam. According to the sandwich structure, the quasi-zero-stiffness resonator of a novel structure serves as a core body, wider application in the ultra-low frequency vibration reduction field can be achieved, the band gap is adjustable, and the problems that a traditional metal base material structure is high in band gap frequency and limited in application field can be solved.

The invention provides an arc-shaped beam bending device for steel structure machining, and belongs to the technical field of machining. According to the structure, a pressing roller is connected to a sliding block, a plurality of electric cylinders are arranged on a base table, the free ends of the electric cylinders are connected with pushing rollers, a plurality of first motors are arranged on the base table, guide wheels are connected to main shafts of the first motors, a base is fixedly connected to the side of the base table, and a sliding way and a rack are fixedly connected to the base; the rack is parallel to the sliding way, a sliding table is arranged on the sliding way, a gear is arranged on the sliding table, the gear and the rack are in matched transmission, a second motor is fixedly arranged on the sliding table, and the second motor is in transmission connection with the gear. Bending machining is carried out on the conveying channel of the steel beam through the push rollers and the guide wheels, and the steel beam bending machine is suitable for high-hardness and large-curvature machining scenes and has the high yield. Meanwhile, the cutting mechanism and the welding mechanism are additionally arranged, multi-procedure operation can be continuously completed, and the overall process efficiency is improved.

The invention relates to a variable-width volute spiral spring design method and a volute spiral spring, and belongs to the technical field of volute spiral springs.The variable-width volute spiral spring design method comprises the steps that S1, polar angles corresponding to plane spiral lines at different arc length positions are determined; s2, determining curvature radiuses corresponding to the planar spiral lines at different polar angle positions; s3, according to different curvature radius parts, the initial section width of the volute spiral spring is designed; and S4, the initial width of the volute spiral spring is adjusted according to the ratio of the radius to the half thickness of different parts, and uniform distribution of bending stress is achieved. The core of the method is that a corresponding width change rule is designed according to a change rule of bending stress along with curvature radius disclosed by a curved beam theory. By means of the method, the maximum bending stress of all the sections can be equal, and therefore the bearing capacity and stability of the volute spiral spring are improved.

A framing system for a construction set comprising a number of interchangeable elements which can be arranged to construct a variety of three-dimensional structures, as well as individual, stand-alone floors, which in turn are adapted to be stacked on one another. In some embodiments, the system comprises at least one central unit, a plurality of outer mid-columns, at least one tie beam corner unit, and / or at least one curved beam unit which cooperate to form a variety of stand-alone floors. The system comprises additional components which increase the stability of the construction set, including but not limited to internal corner brackets, cross pins, cross studs, square panels, and rectangular panels.

The invention belongs to the technical field of cement-based composite metamaterials, and particularly relates to a cement-based metal framework reinforced concrete metamaterial. According to the concrete metamaterial, negative stiffness layers and energy absorption layers are alternately arranged, each negative stiffness layer comprises two curve beams which are symmetrically arranged in the length direction, each curve beam is structurally composed of a repeating unit with the middle portion arched and the two ends pre-bent, each energy absorption layer comprises a framework and concrete, the framework is filled with the concrete, and the negative stiffness layers and the energy absorption layers are arranged in a staggered mode. The framework is formed by periodically arranging a plurality of inwards-concave hexagonal units in the length direction, and the horizontal side length of each inwards-concave hexagonal unit makes contact with the arch in the middle of the curve beam. The non-filled negative stiffness framework area and the negative Poisson's ratio framework area filled with concrete are constructed, function partition response of the structure in different impact stages is achieved, flexible regulation and control of performance can be achieved through topological structure adjustment, and therefore the crashworthiness and adaptability of the structure are improved.

The present invention discloses a support structure for underpasses with anti-pullout piles and a construction method thereof, which solves the problems of high difficulty and low safety factor in the prior art of removing anti-pullout piles during concealed excavation of existing tunnels and / or buildings. The support structure for underpasses with anti-pullout piles of the present invention comprises a connecting steel pipe that connects the existing building structure and the tunnel segment using a pipe curtain method, wherein a curved beam plate is provided on the side of the tunnel segment corresponding to the connecting steel pipe, and a reinforcing ring beam is provided on the side of the existing building structure corresponding to the connecting steel pipe, one end of the connecting steel pipe passes through the tunnel segment and is connected to the curved beam plate, and the other end passes through the existing building structure and is connected to the reinforcing ring beam and / or the existing building structure; after one side of the existing building structure is connected to the tunnel segment via the connecting steel pipe, the existing anti-pullout pile is removed, and then the other side of the existing building structure is connected to the tunnel segment via the connecting steel pipe. The present invention uses the pipe curtain method to construct connecting steel pipes, and uses the connecting steel pipes to connect the tunnel segments and the internal curved steel beams with the upper existing building structure to form a whole, so that the tunnel segments and the upper structure have a common anti-floating effect, and can safely and efficiently realize the safe construction of tunnels passing under existing buildings.

A framing system for a construction set comprising a number of interchangeable elements which can be arranged to construct a variety of three-dimensional structures, as well as individual, stand-alone floors, which in turn are adapted to be stacked on one another. In some embodiments, the system comprises at least one central unit, a plurality of outer mid-columns, at least one tie beam corner unit, and / or at least one curved beam unit which cooperate to form a variety of stand-alone floors. The system comprises additional components which increase the stability of the construction set, including but not limited to internal corner brackets, cross pins, cross studs, square panels, and rectangular panels.

The utility model discloses a tool for guaranteeing the assembling and welding precision of a curved beam of a monorail turnout beam, which relates to the technical field of manufacturing of transportation equipment and specifically structurally comprises a plurality of support components distributed at intervals; the transverse supports are installed between every two adjacent supporting assemblies respectively, and the transverse supports are combined to form an arc-shaped tool face; the supporting assembly comprises two ground platforms which are arranged in a spaced mode. The supporting plates are mounted on the ground platforms in a one-to-one correspondence manner; the two side baffles are installed at the two ends of the ground platform located on the outer side respectively, and the tops of the side baffles are located on the same horizontal plane. The utility model solves the technical problem that the existing monorail turnout curved beam lacks a tool for manufacturing precision.

Disclosed in the present invention are a magnetic-levitation spatial curved beam molding system and molding method. The magnetic-levitation spatial curved beam molding system comprises: a side mold assembly; and functional part mold plate assemblies, wherein two functional mold plate assemblies are correspondingly arranged on two side mold plates, respectively, each functional part mold plate assembly comprises functional part mold plates used for locating a magnetic levitation functional part and at least two vertical adjustment assemblies, and driving ends of vertical adjustment parts are movably fitted with the bottoms of the functional part mold plates, respectively so as to adjust the spatial locations and angles of the functional part mold plates. The functional mold plate assemblies are provided to locate and mount the magnetic levitation functional part, and the vertical adjustment assemblies and lateral adjustment parts are provided to implement any adjustment of the spatial angles and locations of the functional part mold plates, so as to satisfy the requirement of adjusting the spatial location of the magnetic levitation functional part on a spatial curved beam, such that the arrangement location of the magnetic levitation functional part can be better matched with the structure of the spatial curved beam, and the molding precision of the spatial curved beam is ensured.

The utility model relates to a straddle carrier frame which comprises a main frame, extending frames are symmetrically arranged at the left end and the right end of the main frame, each extending frame comprises a bearing beam and a supporting base connected with the main frame, and the supporting bases are arranged at the two ends of the bottom of the bearing beam. The supporting base comprises a transverse plate arranged at the lower end of the bearing beam and a bent beam used for supporting the transverse plate, and reinforcing ribs are welded to the connecting position of the bent beam and the main frame. The design of the extension frame allows the frame to adapt to a smaller plant space while keeping the strength, and is very useful for a warehouse or a factory environment with limited space. By using the camber beams and the supporting transverse plates, the length of the supporting transverse plates is shortened, so that the weight of the frame is reduced, and meanwhile, the required strength is maintained.

The utility model provides a bridge girder erection machine capable of satisfying double-layer cast-in-place beam height limit width limit beam erection construction, which comprises a machine arm, a first column, a second column, a hanging curved beam and a hanging beam crane, the first column is installed on a lower ear beam at the front end of the machine arm and fixedly connected with the machine arm through a gear rack, the second column is installed on an upper ear beam of the machine arm, and the hanging curved beam is fixedly connected with the machine arm through a gear rack. The second column is fixedly connected with a machine arm through a gear rack, an anchoring cross beam is arranged on one side of the machine arm, a front beam transporting vehicle and a rear beam transporting vehicle are arranged below the machine arm, and a hanging curved beam is installed on one side of an upper lug beam of the machine arm. The device is suitable for the width-limiting working condition of portal piers after construction of upper-layer cast-in-place beams of double-layer beams erected by a bridge girder erection machine and the height-limiting working condition of erecting lower-layer beams, low-clearance-height beam erection of the lower-layer beams under the double-layer beam working condition can be achieved, and narrow-width space beam erection of the lower-layer beams under the double-layer beam working condition can be achieved; the anchoring type hanging curved beam is adopted to replace a second column to hang the machine arm, and the hole passing and beam erecting requirements of the bridge girder erection machine are met.

The utility model relates to the technical field of curved beam construction, and provides a curved steel box beam pushing device which comprises a bottom frame. The plurality of transverse pushing devices are arranged on the bottom frame and are used for linearly pushing the steel box girder; the multiple steering pushing devices are arranged on one side of the transverse pushing devices, one transverse pushing device and one steering pushing device form a group, and the multiple groups jointly conduct pushing operation on the steel box girder. By means of the technical scheme, the problem that in the prior art, after relative rotation of the beam body occurs, an existing pushing device can only move transversely or longitudinally, rotation of the beam body can be achieved only through other methods by field operators, and consequently the construction efficiency of the curved beam is low is solved.

A constant force mechanism comprises a rack, a moving part, an output part, a positive stiffness structure and a negative stiffness structure, and the moving part is movably arranged on the rack; the output part is movably arranged on the rack, and the output part is movably connected with the moving part and drives the moving part to move, so that the output part and the moving part get close to each other or get away from each other; the positive stiffness structure comprises a first curved beam and a second curved beam which are connected between the rack and the moving part, and the first curved beam and the second curved beam are arranged in a crossed mode. The negative stiffness structure comprises a first permanent magnet and a second permanent magnet, the first permanent magnet is arranged on the rack, the second permanent magnet is arranged on the side, away from the positive stiffness structure, of the moving part, and the S pole of the second permanent magnet is opposite to the N pole of the first permanent magnet, or the N pole of the second permanent magnet is opposite to the S pole of the first permanent magnet. According to the constant force output device, the elastic deformation force of the positive stiffness structure and the magnetic force of the negative stiffness structure are overlapped, so that the resultant force is kept constant within a certain displacement range, and constant force output is achieved.

The invention relates to the technical field of metamaterials, in particular to a controllable buffering and energy-absorbing negative-stiffness metamaterial which is formed by periodically arranging a plurality of same unit cells. The unit cell includes: a frame; the curved beam is arranged in the frame; the push rod is movably arranged on the frame and is in transmission connection with the curved beam; the air bag is arranged between the frame and the curved beam, and the air bag and the push rod are located on the two sides of the curved beam respectively; adjacent unit cells on different layers are connected with the middle parts of the curved beams and the bottom of the frame through push rods; the adjacent unit cells located on the same layer are connected through a shared frame. The curved beam is of a bistable structure, and after the curved beam is subjected to geometric deformation under the action of an external load, the curved beam can be converted from an initial first stable state to a second stable state and keep a configuration. A curved beam with a buckling step property and an air bag with controllable gas pressure are used, and through combination of the curved beam with the buckling step property and the air bag with controllable gas pressure, the negative stiffness metamaterial with the curved beam capable of being controlled to reset and used for buffering and energy absorption is constructed.

The invention discloses a knee joint assisting exoskeleton, and belongs to the field of exoskeletons. The first and second inertial measurement sensors are arranged on the thigh and shank clamp mechanisms; a shell of the power assisting mechanism is fixed to the thigh clamp mechanism. A first rack and a second rack are arranged on the two sides of the shell in a sliding mode. The motor is fixedly arranged on the shell and sleeved with the first gear, the second gear and the third gear are meshed with the first gear, the fourth gear and the third gear are meshed, and the second gear and the fourth gear are meshed with the first rack and the second rack on the corresponding side. Two ends of the first and second connecting rods are respectively fixed with the lower parts of the two first and second racks; the first ends of the first and second curved beams are respectively sleeved on the first and second connecting rods; two ends of the third connecting rod are fixed with the shank clamp mechanism; the second ends of the first curved beam and the second curved beam sleeve the third connecting rod; the plantar pressure sensor is arranged on the plantar; the first inertial measurement sensor, the second inertial measurement sensor, the motor and the plantar pressure sensor are electrically connected with the development board. Accurate matching of knee joint motion characteristics and rigidity requirements can be achieved.

The present invention discloses a deformation mechanism for the front middle section of a supersonic aircraft cabin. The driving mechanism includes a curved beam, which is the main load-bearing structure of the driving mechanism and is fixed to the front and rear ends of the front middle section of the aircraft cabin; four fan-shaped bottom plates of the same size are equally fixedly connected to the curved beam; a linear guide rail is connected to and fully fits the bottom of the curved beam, and a linear motor group is provided on the linear guide rail, which moves along the linear guide rail; the linear motor group is connected to a slider group through a push rod; a guide rail is provided on the fan-shaped bottom plate for the slider group to move up and down; a synchronous connecting rod passes through the holes on the slider group and the perforated plate to realize the synchronous movement of the slider group; the driving mechanism of the present invention is a synchronous motion device of three groups of slider mechanisms driven by a single motor module, which realizes the problem that the front middle section of a single aircraft cabin has a variable lift-to-drag ratio to meet different flight missions.

The application relates to the technical field of highway and railway bridge design, and discloses a corrugated steel web curved box girder torsional stress analysis method based on prestress effect, which comprises the following steps: S1, determining the mechanical characteristics of the corrugated steel web box girder bridge; S2, performing equivalent load processing on the prestress effect and performing reasonable simplification; S3, establishing a constraint torsion differential equation of the corrugated steel web combined curved box girder to obtain the constraint torsional normal stress and the constraint torsional shear stress of the required section; S4, combining the curved beam boundary conditions, the torsional double moment and the torsional stress formula of the box girder under various load conditions, adopting the initial parameter method to superimpose the boundary conditions into the general solution form of the constraint torsion differential equation of the corrugated steel web combined curved box girder, extracting the calculation data of the torsional stress of the corrugated steel web combined curved box girder, and analyzing to obtain the torsional stress result of the corrugated steel web combined curved box girder. The corrugated steel web curved box girder bridge torsional performance based on the prestress effect is researched by adopting the application.

The invention relates to a quasi-zero stiffness vibration isolation cell based on a flexible curved beam, a design method and a vibration isolator. Each cell comprises a first platform, a second platform, two first flexible curved beams and n second flexible curved beams, and n is a positive odd number. The first platform and the second platform are arranged in parallel in a spaced mode, the flexible curved beams are arranged between the two platforms, the n second flexible curved beams are arranged between the two first flexible curved beams arranged in the same direction, one end of each flexible curved beam is in rigid connection with the first platform through a support, and the other end of each flexible curved beam is in rigid connection with the second platform through a support. The mandrels of the flexible curved beams are cubic non-uniform B-spline curves defined by the same control point, the width of the cross section of the second flexible curved beam is twice that of the cross section of the first flexible curved beam, a gap is formed between every two adjacent flexible curved beams, and the flexible curved beams are arranged at an angle of 180 degrees. The cellular structure is simple and compact, most of harmful vibration can be effectively isolated, and yawing moment in the horizontal direction can be mutually offset.

A radiotherapy device (100, 320) and a magnetic resonance guided radiotherapy system (300, 400, 500, 600, 700). The radiotherapy device (100, 320) can include an electron gun (110) and a curved beam current deflection unit (120, 409, 509, 609, 709). The beam current deflection unit (120, 409, 509, 609, 709) is configured to accelerate an electron beam output by the electron gun (110) over a range of magnetic field strengths (B0). The magnetic resonance guided radiotherapy system (300, 400, 500, 600, 700) can include the radiotherapy device (100, 320) and a magnetic resonance imaging device (310).

The utility model discloses a special template for assembling and welding a roof framework of a passenger car, which belongs to the field of frame welding and comprises a template body, a first flat gasket is mounted at the upper top end of the template body through a cylindrical head socket head cap screw, a compression component is arranged on one side of the template body, and a second flat gasket is mounted at the other side of the template body. The pressing assembly comprises an edge beam pressing device and a pressing device screw combination, the edge beam pressing device is installed at the upper top end of the first flat gasket, the pressing device screw combination is installed on the outer wall of the edge beam pressing device, and through cooperative use of all the devices, in the machining process, the edge beam pressing device is used for pressing the edge, so that the machining efficiency is improved. The profile tolerance between the camber beam and the edge beam is guaranteed so as to achieve the effect of improving the flatness, meanwhile, the flatness between the longitudinal beam and the camber beam is guaranteed through the inner base plate and the outer base plate, the accuracy of the coach roof during machining and welding is further improved, the welding quality is improved, and the consistency between formworks can be improved through the arrangement of the multiple fixing plates.

The present invention discloses a landing gear, a design method thereof, and an aircraft, relating to the technical field of landing gear. The landing gear comprises at least two skids, at least two buffer beams, and at least two mounting brackets. The two skids are arranged opposite each other. The buffer beam connects the two skids and protrudes upward. The buffer beam comprises a transverse beam section and two curved beam sections, with the curved beam sections connected between the transverse beam section and the skids. The mounting brackets are used to connect to the aircraft body. The two mounting brackets are disposed at opposite ends of a transverse beam section, with a spacing d between the two mounting brackets. The width of the landing gear in the distribution direction of the mounting brackets is D, and 0.3≤d / D≤0.7 is achieved. The technical solution provided by the present invention can enhance the cushioning and energy absorption effect of the landing gear.

The utility model belongs to the technical field of cantilever bridge fabrication machines, and particularly relates to an outer mold suspender suitable for a curved beam intelligent suspension grouting bridge fabrication machine, which comprises a suspender, a suspender connected to the bottom of the suspender and a conversion suspension frame connected to the bottom of the suspender, and an anti-falling rod group is connected between the bottom end of the suspender and the top end of the conversion suspension frame. The hanging belt is arranged on the anti-falling rod set in a sleeving mode, the anti-falling rod set comprises an upper rod body, a lower rod body, a lock hook, a lock groove and a locking spring, the top end of the upper rod body is connected with the bottom end of the hanging rod through a spherical hinge structure, the bottom end of the lower rod body is connected with the top end of the swivel hanging frame through a spherical hinge structure, and the bottom end of the upper rod body is inserted into the lower rod body from the top end of the lower rod body. The lock groove is formed in the side face of the lower rod body, the lock hook is arranged in the upper rod body in a penetrating mode, the top end of the lock hook extends out of the side face of the upper rod body, the bottom end of the lock hook abuts against the inner wall face of the lower rod body, and the locking spring is arranged between the upper rod body and the lock rod. The anti-falling device has the advantages of falling prevention, high safety and high stability.

1. Name of the product in this design: Folding Chair (Curved Beam Camel Chair). 2. Purpose of this design: This design is for sitting or resting. 3. The key design feature of this product is its shape. 4. The image or photograph that best illustrates the design's key points: a 3D model.

The embodiment of the present disclosure provides an anti-impact and vibration-reducing and noise-reducing integrated multifunctional metamaterial structure and a preparation method thereof, and relates to the technical field of multifunctional metamaterials.The method comprises the following steps: manufacturing a super-elastic material structure, which is based on a curved beam structure; taking the super-elastic material structure as a core and a polygonal metal frame as a boundary, a single cell structure with super-damping effect is constructed; the single cell structure is constructed into a lattice structure in the form of a fractal structure, and the lattice structure is arranged according to a preset requirement to synthesize a metamaterial plate; and the polygonal metal frame boundary form and the number of the metamaterial plates are adjusted according to an application scenario to form an anti-impact and vibration-reducing and noise-reducing integrated multifunctional metamaterial structure.The anti-impact and vibration-reducing and noise-reducing integrated multifunctional metamaterial structure and the preparation method thereof can solve the defects that the current anti-impact metamaterial structure has a large thickness and a single function and is difficult to be applied to actual engineering problems.

Disclosed in the present invention are an automatic positioning and adjusting system and method for a maglev functional component on a guideway, for use in positioning the maglev functional component on a guideway forming system. The system comprises: functional component die plates, the functional component die plates being configured to position and mount maglev functional components; a functional component die plate adjusting system, the functional component die plate adjusting system being configured to adjust the spatial positions of the functional component die plates on a forming system; a measuring system, the measuring system being configured to measure position data of the functional component die plates or the maglev functional components on the functional component die plates; and a control system, the control system being configured to acquire measurement data of the measuring system and control the functional component die plate adjusting system on the basis of the position data measured by the measuring system and target position data of the functional component die plates or the maglev functional components. The present invention can realize rapid adjustment and positioning of a functional component die plates, thereby ensuring the position precision of maglev functional components on a guideway, and well satisfying the requirements of rapid and accurate forming of a spatial curved beam.

The utility model discloses a kind of automobile front suspension beam structure, it is related to automobile parts technical field, to solve the problem of traditional beam and plate spring connection positioning difference, easy to loosen. It includes beam body, beam body contains straight beam part and two end bent beam part, and connecting cylinder is equipped at the two ends of bent beam part;The top surface of the two ends of straight beam part is equipped with connecting square plate, and connecting square plate and straight beam part are equipped with boss, and boss is equipped with connecting hole, and connecting square plate is equipped with positioning recess and positioning hole. Straight beam part and bent beam part are equipped with contour reinforcing rib, and diagonal reinforcing rib and weight-reducing hole are equipped between straight beam part contour reinforcing rib;Boss is equipped with step hole, and connecting reinforcing rib is equipped between boss, and bent beam part and connecting cylinder joint are equipped with reinforcing protrusion. The structure can improve the positioning accuracy and stability of plate spring connection, and consider strength and light weight, adapt to commercial vehicle demand.

The utility model provides a belt conveyor carrier roller frame convenient to install and correct. The belt conveyor carrier roller frame comprises side supporting plates and a bent beam. The two ends of the camber beam are connected with the side faces of the tiger claws respectively, the multiple carrier rollers are evenly installed on the camber beam, the edge supporting plates are fixed to the tops of the tiger claws, the tiger claws at the two ends of the camber beam are installed on the edge beam pipes respectively, the lower ends of the edge beam pipes are supported by the multiple stand columns, and the lower ends of the opposite stand columns are connected through the connecting beam. The lower rollers are further installed between the opposite stand columns and located above the connecting beams, the carrier rollers are installed on the edge beam pipes through the tiger claws and locked through the elastic pins, and the installation process and steps of the belt are simplified; and after the belt deviates, the elastic pin can be pulled out to adjust the position of the tiger claw back and forth so as to correct the belt.

The application discloses a compliant variable stiffness curved beam supporting ultra-low frequency vibration isolation device, which comprises a main frame, a main connecting rod movably arranged in the main frame, and a negative stiffness mechanism and a positive stiffness mechanism coupled in parallel to the main connecting rod, wherein the negative stiffness mechanism with nonlinear negative stiffness is sleeved on the main connecting rod, the positive stiffness mechanism with nonlinear positive stiffness is fixed at one end on the main frame and is fixedly connected at the other end with the main connecting rod, the nonlinear positive stiffness mechanism is used for modulating the nonlinear negative stiffness mechanism, and the high static stiffness and low dynamic stiffness characteristics are realized. The application adopts the arc-shaped beam with double-end clamping to provide the nonlinear negative stiffness, adopts the spiral-shaped beam to provide the nonlinear positive stiffness and the guiding function, and adopts the parallel arc-shaped beam and spiral-shaped beam to realize the high static stiffness and low dynamic stiffness characteristics. The stiffness of the vibration isolation device only needs to be modulated by adjusting the coupling connection relationship of the positive stiffness mechanism and the negative stiffness mechanism, the configuration parameters of the elastic elements do not need to be changed or the elements do not need to be replaced, the stiffness modulation is flexible, and the ultra-low dynamic stiffness can be easily realized. The vibration isolation device adopts the compliant design, is convenient to assemble, has no motion gap and contact friction limitation, and can realize the ultra-low frequency vibration isolation.

The invention relates to the technical field of pipeline vibration reduction, in particular to a low-frequency vibration reduction device suitable for pipelines of various specifications. The upper circular hoop and the lower circular hoop are oppositely arranged and are connected through a bolt; the plurality of softened rigidity annular pads are arranged on the inner sides of the upper circular hoop and the lower circular hoop at intervals; the side faces of the two softening rigidity annular pads are arranged on the two sides of the lower circular hoop in an attached mode respectively. The softening rigidity base and the softening rigidity annular pad are both made of elastic materials. The softening rigidity base is provided with a plurality of base vibration reduction holes, and the base vibration reduction holes are spaced through oblique and long base curved beams and vertical and short base center rods. The softened rigidity annular cushion is provided with an annular cushion center hole and a plurality of annular cushion side holes which are spaced through annular cushion curved beams. The vibration response of pipelines of different specifications under the low-frequency working condition can be remarkably reduced, and therefore effective control over low-frequency vibration is achieved; and the overall deformation and the equivalent stiffness of the pipeline system can also be regulated and controlled so as to meet the requirements of different working conditions.