681results about How to "Structural symmetry" patented technology

A 4-freedom parallel robot structure with passive constraint branch is disclosed, which contains different two passive constraint branch structures and can be used for robot to realize one axial movement and three different rotations. Its advantages are high parallel rigidity and load-bearing power, simple structure, high precision and low cost.

The invention discloses an unfoldable unit of a triangular prism and an unfoldable support arm consisting of the unfoldable units, solving the problems that the existing hinged type support arm is large in folded size and low in repeated unfolding precision. According to the unfoldable unit, an upper triangular frame and a lower triangular frame are arranged from top to bottom in parallel; each corresponding top angle between the upper triangular frame and the lower triangular frame is respectively supported by a triangular prism folding arm and is rotatably connected with the triangular prism folding arm; a group of triangular prism inhaul cable assembly is arranged at the inner opposite angle of a rectangular plane formed by the upper triangular frame, the lower triangular frame and two adjacent triangular prism folding arms; and each two adjacent triangular prism unfoldable units are rotatably connected through a transit unfolding component. With the adoption of the inhaul cable component provided by the invention, the problem that inhaul cables at opposite corners are wound and move irregularly; and meanwhile the overall rigid and the repeated unfolding precision of the support arm are enhanced. The unfoldable unit is used in a satellite, a space station and a space probe.

An adjustable experimental platform with 3,4,5-SPS type parallel mechanism for robot, machine-tool, or sensing element is disclosed. 3,4 or 5 linear drive branches are distributed between upper platform and base in polygonaly symmetrical mode. One of 4 or 5 linear drive braches is arranged in the center of platform and base. The both ends of each branch have a ball set consisting of the rotation set A formed by connecting one end of said branch with ring frame, the rotation set B formed by connecting ring frame with supporter, and the rotation set C formed by connecting supporter with axle sleeve. The vertical and transverse pins are used to change the freedom of ball set.

The invention provides a pipeline clamping tool and a pipeline lifting method. the pipeline clamping tool comprises a pedestal, a clamping part of the clamping pipeline which is hinged on the pedestal by a hinge shaft; a first hydraulic cylinder which drives the rotation of the clamping part and is arranged on the pedestal and is connected to the clamping part; and a locking part which is used for locking the clamping part and is arranged on the pedestal in a movable mode. The invention also provides a pipeline lifting method, the pipeline lifting method comprises the following steps: driving the rotation of the clamping part by the first hydraulic cylinder and clamping the pipeline, then driving the locking part, preventing the rotation of the clamping part, and then lifting the pipeline and stopping the oil supply on the first hydraulic cylinder during the lifting process.

A scheme that a rudder system with a wing spreading locking function pushes rudder sheets to spread simultaneously and lock the rudder sheets is adopted by the invention. After a rocket projectile is launched, the rudder system is powered by a missile-borne controller; after a rudder spreading command is emitted, the rudder system controller receives the rudder spreading command of the missile-borne control system; current amplification is performed after the rudder system controller receives a rudder spreading command signal, so that a pin pusher is started, and a pushing disc is pushed to spread the four rudder sheets simultaneously; after spreading angles reach 90 degrees, limiting is performed through the locking mechanism, and the whole wing spreading locking function is finished; and then, the missile-borne controller gives a rudder deflecting command, so that a rudder engine is controlled to drive the rudder sheets to swing, and a servo control function is realized. Meanwhile, for ensuring that the sailing posture of the rocket projectile is not affected, the spreading time of the four rudder sheets is very short and the asynchronism of spreading is very low.

A high-power bi-directional non-recovery spring magnetic valve including permanent magnets has an upper magnetic circuit part and lower magnetic circuit part symmetrically disposed and connected together via an armature connection rod and a housing connection ring, the upper magnetic circuit part comprises an upper iron core, an upper housing, an upper coil, an upper annular permanent magnet, an upper yoke iron and an upper push rod, the lower magnetic circuit part comprises a lower iron core, a lower housing, a lower coil, a lower annular permanent magnet, a lower yoke iron and a lower push rod. The magnetic valve comprising permanent magnets realizes bistable-state magnetic retaining, and has an adjustable retaining force for permanent magnet adjustment, quick response, and high output force.

The invention discloses a manufacturing method for a thin coreless substrate. The method comprises the steps of a, sequentially stacking first copper foil, first prepreg and second copper foil for conducting pressing fit for the first time to obtain a first substrate, and manufacturing a second circuit on the second copper foil, wherein the second circuit comprises a first bonding pad, and the first bonding pad extends towards the periphery to form an electroplating frame; b, on the premise that the electroplating frame is exposed, sequentially stacking second prepreg and third copper foil on the second copper foil for conducting pressing fit for the second time to obtain a second substrate, and manufacturing a first circuit and a third circuit respectively so as to obtain a substrate workblank; c, conducting pressing fit for the third time; d, forming a first blind hole and a second blind hole, and filling the first blind hole and the second blind hole by the adoption of the electroplating hole filling technology respectively to obtain a substrate model. The thin coreless substrate is manufactured through the manufacturing method, is a three-layer coreless substrate, has the symmetric pressing-fit condition and the pressing-fit structure, and achieves internal layer circuit embedment.

The invention provides high-transparency polyurethane elastomer and a preparation method thereof. The high-transparency polyurethane elastomer is mainly prepared by adopting the following components: a polyether glycol mixture, an aliphatic isocyanate mixture, a chain extender and maleic anhydride grafted polypropylene; the polyether glycol mixture is a mixture of polytetramethylene ether glycol, polyoxytetramethylene glycol and polypropylene epoxy glycol; the aliphatic isocyanate mixture is a mixture of hexamethylene diisocyanate and isophorone diisocyanate; the chain extender is a mixture of 1,4-isophorone diisocyanate and diethylene glycol. By adjusting the dosage ratio of all components, by utilizing the synergism of HDI and IPDI, the transparency and transparent duration of the polyurethane elastomer are improved; the mixture of the 1,4-isophorone diisocyanate and diethylene glycol is used as the chain extender, so that the crystallization of a hard section of the polyurethane elastomer is inhibited, a plurality of small sections are formed, the specific surface area is increased, the deformation of a soft-section base material is effectively inhibited, and the mechanical performance is improved.

The invention provides a multi-dimensional force sensor calibration device with controllable poses. The multi-dimensional force sensor calibration device comprises a fixing platform, drive mechanisms, connecting rod mechanisms and a moving platform. The upper ends of the drive mechanisms and the lower ends of the connecting rod mechanisms are connected to form drive connecting rod mechanisms. The upper ends of the six drive connecting rod mechanisms are hinged to the moving platform through universal hinges, and the lower ends of the six drive connecting rod mechanisms are hinged to a fixed platform to form a six-freedom-degree parallel mechanism. The six drive connecting rod mechanisms are divided into three groups. Every two adjacent drive connecting rod mechanisms form one group and are arranged in the mode shaped like a Chinese character 'ba'. The poses of a calibration platform can be controlled and changed, and the calibration device has the function of calibrating a sensor dynamically and statically, and is complete in function, convenient to operate, high in calibration precision and capable of being well applied to practical engineering.

The structure of a wear-resistant, drag-resistant and low-temperature resistant flexible cable comprises a cable core, wherein the cable core is formed by twisting three main wire cores, three ground wire cores and a cable core gap semiconductive filler, each main wire core comprises a cross-linking wire core formed by co-extruding a conductor, a semiconductive nylon strap, a conductor shielding layer, an insulation layer and an insulation shielding steam continuous vulcanization layer, each ground wire core comprises a conductor and a semiconductive material steam continuous vulcanization extruded on a surface of the conductor, an isolation strip, an inner sheath, a fiber weaving reinforcement piece and an outer sheath are sequentially applied outside the cable core to form a finished cable, the conductors adopt tin-plated annealed copper conductors, filaments of the tin-plated annealed copper conductors are more slim, and the diameter ranges of the filaments are 0.1-0.41 millimeter. A cable fabrication method comprises the steps of fabricating the main wire cores and the ground wire cores; fabricating the cable core; winding an isolation strip; extruding the inner sheath; weaving the reinforcement layer; and performing steam continuous vulcanization extruding or radiating the cross-linking outer sheath. The cable fabricated according to the method can conform to the design and application requirements, and meanwhile, the qualified rate reaches over 99%.

The invention discloses a composite ultrasonic elliptical vibratory cutting device. The device consists of an ultrasonic vibrating unit, a cylindrical servo cutter frame, hollow piezoelectric ceramic and a base, wherein a cutter is arranged at the output end of the ultrasonic vibrating unit; the ultrasonic vibrating unit is arranged in the hollow piezoelectric ceramic; the hollow piezoelectric ceramic is arranged in the cylindrical servo cutter frame; the base is arranged on the end part of the cylindrical servo cutter frame; and the cylindrical servo cutter frame is provided with four elastic hinge structures. Due to the design of symmetrical hinges, cylindrical ceramic is prevented from being deviated while driving the cutter; and the processing accuracy of the surface appearance of a nanoscale three-dimensional micro-structure of the cutter is realized through the gapless transmission of the elastic hinges. The ultrasonic vibrating unit adopts two exciting sources with different structures, so that ultrasonic vibration of the cutter in a longitudinal direction and a bending direction is realized during processing. The cutting device of the invention can be suitable for making shark skin imitation structural skin.

The invention discloses an isolated three-level bidirectional DC-DC converter with a coupling inductor. The isolated three-level bidirectional DC-DC converter comprises a high-voltage side input capacitor, a low-voltage side input capacitor, a high-voltage side power supply, a low-voltage side power supply, a first power switching tube, a second power switching tube, a third switching tube, a fourth power switching tube, a first diode, a second diode, a third diode, a fourth diode, a first coupling filter inductor, a second coupling filter inductor, wherein the first coupling filter inductor and the second coupling filter inductor are coupled to each other. The isolated three-level bidirectional DC-DC converter has the advantages of small output current ripple and low loss of switching tubes, and is also relatively simple in structure.

The invention belongs to the field of flexible mechanisms, relating to a multistable mechanism realizing method based on a single bistable mechanism and external characteristics thereof. A framework and a flexible bistable mechanism in the framework are comprised. The left end and the right end of the flexible bistable mechanism are fixed in the framework. The multistable mechanism realizing method is characterized in that connecting rod slide block mechanisms are in parallel to a horizontal axis of the flexible bistable mechanism; the connecting rod slide block mechanisms comprise lead rails, slide blocks and connecting rods; the slide blocks are in the lead rails; the lead rail of the next level of the connecting rod slide block mechanism is mutually vertical with the adjacent lead rail of the upper level of the connecting rod slide block mechanism; the connecting rod of the first-level connecting rod slide block mechanism is connected with a shuttle of the flexible bistable mechanism; and the last-level slide block is in the stable position of N=2M+1 through movement of the slide block in each level of the connecting rod slide block mechanism and the change of the upper position and the lower position of the shuttle of the flexible bistable mechanism, wherein M is the number of the connecting rod slide block mechanisms; and the minimum value of the M is 1. The invention depends on elastic potential energy stored in the flexible bistable mechanism to keep stable state, and does not need durative action of external forces.

Disclosed is an ultra-wideband power divider based on an exponential gradient. The ultra-wideband power divider is composed of microstrip lines and ports of the microstrip lines, wherein the microstrip lines are located on a dielectric slab and used as a power divider body, and achieve matching and transmission characteristic transformation. The ultra-wideband power divider is provided with one input port, two equi-amplitude and in-phase output ports, an impedance conversion circuit and an ultra-wideband power distribution circuit, wherein the impedance conversion circuit and the ultra-wideband power distribution circuit are located between the input port and the output ports. The characteristic impedance of each of the microstrip lines of the three ports is 50omega, and the whole circuits are vertically symmetrical. One microstrip line based on the exponential gradient is adopted for the input port, the microstrip line with a characteristic impedance of 50omega is matched to an input end of the ultra-wideband power distribution circuit, the microstrip lines with a characteristic impedance of 25omega are divided into two vertically-symmetrical output paths, four sections of semicircular microstrip lines are in cascade connection to output equi-amplitude and in-phase signals, the characteristic impedance of each section of semicircular microstrip line is 50omega, the electrical length of each section of semicircular microstrip line is pi/2, an isolating resistor is connected between each pair of microstrip lines arranged up and down, and the isolating resistors are different from one another. The ultra-wideband power divider based on the exponential gradient is good in transmission performance, and relative bandwidth can reach more than 100%.

Provided is a phosphaphenanthrene-based compound represented by the following chemical structure:

The phosphaphenanthrene-based compound can be added in a resin composition and made into a prepreg or resin film. The prepreg or resin film made from such resin composition has low coefficient of thermal expansion, low dielectric constant and dissipation factor, and flame retardancy, thereby being suitable for copper-clad laminate or printed circuit board.

The invention discloses a symmetrical all-fiber Fabry-Perot sensor, a first single-mode fiber is welded with a first multi-mode fiber, and a second single-mode fiber is welded with a second multi-mode fiber; tail ends of the first multi-mode fiber and the second multi-mode fiber are provided with concave cavities; the concave cavities of the first multi-mode fiber and the second multi-mode fiber are in butt joint with each other to form an FP cavity. According to the symmetrical all-fiber Fabry-Perot sensor and the manufacturing method thereof provided by the invention, the structure is small and exquisite, manufacture is easy and cost is low, the fiber sensor can utilize a chemical corrosion method to obtain a long Fabry-Perot cavity, is symmetrical in structure and low in stripe fineness, is little affected by temperature, and can utilize a phase method based on Fourier transform to realize measurement of pressure and strain under high temperature.

The invention discloses a comprehensive detecting device for detecting internal defects of a drainage pipeline. The comprehensive detecting device comprises an equipment carrier capable of floating on water, wherein a camera capable of detecting the part above the pipeline water is arranged on a water part of the equipment carrier, and a camera illuminating lamp is arranged; a sonar sensor capable of detecting the pipeline underwater part is arranged on an underwater part of the equipment carrier; and controlling and receiving signals of the camera and the controlling and receiving signals of the sonar sensor are respectively connected with a controller by virtue of a cable. The comprehensive detecting device disclosed by the invention has the characteristics of complete functions, wide detecting range, safe and reliable work, and the like, and can be used for comprehensively detecting the internal conditions of the drainage pipeline.