68results about How to "Reduce design weight" patented technology

A motion tracking system for tracking an object composed of object parts in a three-dimensional space. The system comprises a number of magnetic field transmitters; a number of field receivers for receiving the magnetic fields of the field transmitters; a number of inertial measurement units for recording a linear acceleration; a number of angular velocity transducers for recording angular velocities. The system further comprises a processor for controlling the transmitters and receiving signals coming from the field receivers and the inertial measurement unit; which processor contains a module for deriving orientation and / or position information of the constituent object parts of the object on the basis of the received signals. The processor is configured for intermittently controlling the transmitters transmit at a predetermined frequency, wherein the position and / or orientation information is derived by periodically calibrating the motion information coming from the inertial measurement unit with the motion information coming from the magnetic field receivers.

The invention relates to a power generation device, in particular to a vertical-axis clutch type wind power generation device so as to solve the problems that an existing large-power vertical-axis wind power generator is difficult in self-starting and braking and low in power generation efficiency. The vertical-axis clutch type wind power generation device comprises a wind wheel, a first transmission shaft, a wind wheel locking device, a first coupler, a second transmission shaft, a third coupler, a clutch, a speed increasing gear, a support, a second coupler, a power generator, a tower and two brake devices. The vertically-arranged first transmission shaft is rotationally arranged on the top of the tower, one brake device is arranged on the top of the tower, and the wind wheel locking device is arranged on the top of the part, below a flange plate, of the tower. The upper end of the first transmission shaft is connected with the wind wheel, the lower end of the first transmission shaft is connected with the first coupler, and the speed increasing gear is fixed to the support. The clutch is connected between the second transmission shaft and an input shaft of the speed increasing gear, an output shaft of the speed increasing gear is connected with an input shaft of the power generator through the second coupler, and the other brake device is arranged on a power generator shell. The vertical-axis clutch type wind power generation device is used for wind power generation.

The invention discloses a cloth control method for cloth equipment. A cloth arm rack of the cloth equipment comprises at least two arm sections. The cloth control method comprises the steps of: firstly, controlling the first arm section of the cloth arm rack to move to a vertical state, and enabling the first arm section to maintain in the vertical state; and secondly, controlling the other arm sections of the cloth arm rack to move so as to carry out the cloth operation. Additionally, the invention further provides the cloth equipment for realizing the cloth control method. According to the cloth control method, on the premise of ensuring a maximum cloth height, by creatively giving up part of cloth semi-diameter, a supporting span of the cloth equipment in cloth operation is reduced, and the probability of lowering the intensity of a supporting leg is provided, so that a size of the flexible supporting leg is enabled to be decreased, the number of corresponding reinforce pieces is enabled to be reduced, thereby the purpose of losing weight of the cloth equipment is effectively reached, and stability and safety of the cloth equipment are effectively guaranteed.

The invention relates to a double-P type radiant tube. The double-P type radiant tube is arranged in a heat treatment furnace and comprises three parallel arrayed straight tubes, and both ends of each straight tube are symmetrically welded with two bent tubes, wherein the middle of one bent tube is provided with an air inlet tube coaxially arranged with the middle straight tube, while the other bent tube is welded with one end of a supporting tube coaxial to the middle straight tube. The manufacture method of the double-P type radiant tube comprises the following steps of: (1) calculating the manufacture size of the double-P type radiant tube; (2) cutting a plate, rolling the plate and welding the plate into the straight tubes; (3) punching and forming a plate into half bent tubes and welding the half bent tubes into the bent tubes; and (4) argon arc welding the manufactured straight tubes and the bent tubes and welding the supporting tube.

The invention discloses a daytime climbing flight method for reducing the weight and size of a solar unmanned aerial vehicle, and belongs to the field of design of air vehicles. The daytime climbing flight method for reducing the weight and size of the solar unmanned aerial vehicle comprises the steps that with 24 hours as a cycle, the solar unmanned aerial vehicle cruises at a normal cruising altitude from the sunrise moment t1 to the time when a secondary power supply is fully charged; from the moment when the secondary power supply is fully charged, residual solar energy is fully used by the unmanned aerial vehicle for climbing flight; the unmanned aerial vehicle starts to descend with power after climbing to the specific altitude, and the unmanned aerial vehicle starts to slide downwards without power from the moment when the secondary power supply starts to participate in power supply till the unmanned aerial vehicle slides downwards to the normal cruising altitude; and the unmanned aerial vehicle cruises all over the night in a constant-altitude mode at the normal cruising altitude by means of energy provided by the secondary power supply till the sunrise moment of the next day, the circulating cycle of one day is ended, and the next cycle is started. According to the daytime climbing flight method for reducing the weight and size of the solar unmanned aerial vehicle, the flight strategy that the solar unmanned aerial vehicle climbs after noon and then falls, so that the energy demand for the secondary power supply is reduced, the weight of the secondary power supply is reduced to a certain extent, the weight and size of the solar unmanned aerial vehicle are reduced accordingly, and the feasibility of the scheme is improved.

The invention relates to the field of flight control, in particular to a design method of a flap driving mechanism and the flap driving mechanism, and aims to solve the problem that the driving mechanism is low in use efficiency when an aircraft flap is loaded heavily and deflects a large angle. According to the design method of the flap driving mechanism, on the basis that a universal coupling is in an original state, a driven shaft is rotated by a preset angle around a hinge point in the anti-clockwise direction, and the current state of the universal coupling is used as the original state to be designed, so that the efficiency loss of the universal coupling is reduced when the flap is driven to rotate by the same angle, and the efficiency of the driving mechanism is greatly improved; meanwhile, on the premise that the external driving load of by the flap driving mechanism remains unchanged, the design load of the driving mechanism is reduced, the design weight of the driving mechanism is reduced, and the reliability of the driving mechanism is improved; the principle is simple and practical, and easy to implement.

The invention relates to a high bit rate data acquisition and transmission system based on a star topology framework. The system comprises a sensor, acquiring and editing units and a central processing unit (CPU), wherein the sensor is used for sensing physical parameters of a measured object, converting the physical parameters into electrical signals and outputting the electrical signals into the acquiring and editing units; the acquiring and editing units adopting an integral design are used for completing power supply of the sensor and signal acquiring and encoding, conditioning the received electrical signals, processing the electrical signals by input filtering, amplification, sampling and analog to digital (A / D) conversion, and transmitting the processed signals into the CPU; the CPU is used for carrying out sequential control on the acquiring and editing units through a control bus so as to enable the acquiring and editing units to output data according to the preset logic, and also used for processing received data output from the plurality of acquiring and editing units in a centralized way, framing the data according to the prescribed form, converting parallel signals into serial signals and outputting the signals into modulation and transmitting equipment. The centralized control and synchronous acquisition method is adopted by the system, so that the system is easy to maintain, automatic fault isolation is realized, and the purposes of synchronous working of the plurality of acquiring and editing units and high bit rate data transmission can be effectively realized.

The invention discloses a main load-bearing structure suitable for a ballistic reentry recovery capsule, and belongs to the technical field of load bearing of a recovery capsule. The main load-bearing structure suitable comprises a head shell, a stabilizing flare, a flare bottom, an instrument panel, a transition bracket, a support base, a platform, a parachute bay device and a pull rod, wherein two ends of the stabilizing flare are respectively butted with the head shell and the flare bottom; the instrument panel is fixed to an upper end frame of the stabilizing flare; the transition bracket is coaxially mounted on the bottom surface of the instrument panel; the platform is connected with the middle bulkhead of the stabilizing flare; the support base is fixed to the upper surface of the platform; the support base is connected with the transition bracket; after a mounting end of the parachute bay device penetrates through the platform, the mounting end is connected with the support base and the transition bracket, and a parachute deployment end is connected with the stabilizing flare through the pull rod after penetrating through the stabilizing flare; a circular gap of the flare bottom is sealed by the spherical surface of the parachute deployment end of the parachute bay device; the structure can bear up under complicated reentry load conditions, meet the requirements of equipment mounting, increase the transversal fundamental frequency of the capsule body, and achieve lightweight design on the premise of satisfying rigidity and strength.

The invention relates to a connecting structure and system of an integrated brake device for a railway vehicle and belongs to the technical field of railway vehicle manufacturing. The connecting structure of the integrated brake device for the railway vehicle comprises a brake valve, a dust collector, a middle body, an air cylinder, a support assembly and a connecting assembly. The middle body is of a plate-type structure. The brake valve and the dust collector are installed at one side of the middle body. The air cylinder and the middle body are connected through the connecting assembly. The air cylinder is installed at the other side of the middle body. The support assembly is located between the air cylinder and the middle body. The connecting structure of the integrated brake device for the railway vehicle is simple and compact in structure and capable of saving space. Brake parts are integrated on the middle body, and all the brake parts and the whole integrated brake device are connected with an external mounting base safely and reliably. According to the connecting system of the integrated brake device for the railway vehicle, by setting connection between the middle part and all the brake parts, connecting stability of the brake parts is improved and connecting safety of the connecting assembly is also improved.

The invention provides a vehicle-mounted tank made of a carbon fiber reinforced composite. The vehicle-mounted tank is formed by combining three to six tank cavities. Each tank cavity is made of an inner liner layer. A rubber air-inflation inner container serves as a die of each inner linear layer, and each inner linear layer is made through a four-dimensional enveloping and winding formation process. The tank cavities are connected with one another through bolts and bonding. Each tank cavity is externally coated with a structural layer. Each structural layer is a glass fiber reinforced thermosetting composite layer and made through a four-dimensional enveloping and winding formation technology. Reinforcing ribs are arranged at the connection positions of the tank cavities. The reinforcing ribs are made of a glass fiber reinforced thermosetting composite and perform hoop winding reinforcing. Through holes are formed among the tank cavities. Supports are arranged at the bottoms of the tank cavities. The vehicle-mounted tank has the beneficial effects that by means of the vehicle-mounted tank made of the carbon fiber reinforced composite, the problem that a metal vehicle-mounted tank is poor in corrosion resistance can be solved; the wall thickness and design weight of a tank body can be remarkably lowered; fuel consumption of a vehicle is reduced; and the vehicle-mounted tank is small in weight, high in strength, resistant to corrosion and static electricity, capable of saving energy, environmentally friendly, good in comprehensive benefit and the like.

The invention relates to a hanging side formwork of a cradle, which comprises a left side formwork, a right side formwork and a hanging device. The upper ends of the left side formwork and the right side formwork have cantilever structures, the left side formwork and the right side formwork are placed on rail beams and are hung on a cast beam section and a front cross beam of the cradle through the rail beams, and the left side formwork and the right side formwork are oppositely braced and fixed through two finely-rolled threaded steel bars. The hanging device comprises phi-36 finely-rolled threaded bars and assorted nut backing plates, wherein the phi-36 finely-rolled threaded bars penetrate through the left side formwork and the right side formwork, the lower ends of the phi-36 finely-rolled threaded bars are fixed on a lower crossbeam through the assorted nut backing plates while the upper ends thereof are fixed on the cast beam section through the assorted nut backing plate, and the scale height of the left side formwork and the right side formwork can be adjusted by pretensioning and drawing so that the left side formwork and the right side formwork can be attached onto the cast beam section. The hanging side formwork of the cradle is an assorted modeling steel formwork of various cradles used for construction of symmetric cantilevers of box girders and particularly suitable for adverse places having higher box girders, heavy sections of the box girders, higher requirement for stability of the side formwork, and strict load control requirements for the cradle.

The invention relates to a mobile phone, which comprises a body, a cover body, a rotating shaft connected between the body and the cover body, a projection module capable of projecting a virtual keyboard, a first image sensor and a second image sensor. The cover body can rotate relative to the body, and is switched between two states of covering on the body and forming an included angle with the body; one end of the body connected with the rotating shaft is extended outwards to form a rotation limiting mechanism; the projection module is arranged on the rotation limiting mechanism; the cover body is provided with a reflecting element; when the cover body covers on the body, the projection module directly projects the virtual keyboard on the surface outside the mobile phone; the first image sensor is started and used for shooting the virtual keyboard so as to sense operated virtual keys of the virtual keyboard; the projection module projects the virtual keyboard onto the body through the reflecting element when the cover body and the body form the included angle; and the second image sensor is started and used for shooting the virtual keyboard so as to sense the operated virtual keys of the virtual keyboard.

The invention provides a manual three-way tolerance adjuster. The adjuster comprises adjusting studs, bolt assemblies and fixing bases, wherein the bolt assemblies comprises bolts and locking pieces;a through hole is formed in the middle of the bottom plate of each fixing base, wherein internal threads are arranged on the inner wall of each through hole; external threads are arranged on the outerwall of the adjusting studs, and bosses are arranged on the top end faces of the adjusting studs; and the adjusting studs and the fixing bases are connected and fixed in a threaded manner. The invention further provides an application and installation method of the manual adjuster in a hidden handle. According to the manual three-way tolerance adjuster and the application and installation methodthereof, threaded preset height installation is adopted, tolerance adjustment in three directions can be completed only through two parts matched with manual adjustment; and meanwhile the structure issimple, the operation is convenient, the strength is extremely high, and the cost is extremely low.

A method of repairing defect in cast iron workpiece, including: machining the workpiece in the area of the defect to remove the defective material and form a chamber opening at a surface of the workpiece; anchoring a receptacle to the workpiece above the chamber (2), the receptacle is provided with an orifice in communication with the chamber; adding molten iron (4) into the receptacle so that it at least part of it flows into the chamber; adding slagging agent (5) into the receptacle; heating the slagging agent and the molten iron with an electrode (6); adding nodulizing agent into the molten iron so as to segregate graphite; and allowing the molten iron and the workpiece to cool down slowly. The above-described technique also has applicability for connecting two cast iron workpieces (11, 12) together.

The invention discloses an airborne electronic module plugging locking puller and aims to provide an airborne tool with good reliability and compatibility. The airborne electronic module plugging locking puller is achieved by the following technical solution that a shaft sleeve (7) sleeved with a torsion spring (8) passes through a lug hole in a horizontal lug elbow of a pull rod (1), a wedge-shaped block (3) is hinged together by a rotating shaft (5) inserted into the shaft sleeve (7) and a washer (6), the pull rod is close to a seat body of a support seat (2) in a vertical direction, and a free end upper lock is locked to a locking hook on a bottom end of the support seat (2). A vertical spring seat at a lower side of a wedge-shaped block lug spring groove pushes a compression spring (4)into a lug spring groove on the top of the wedge-shaped block, a wedge-shaped tapered surface at the top of the wedge-shaped block extends out of an opening in the lug spring groove, and a moving pair linked with a lever of the pull rod is formed. The pull rod rotates around the rotating shaft to form a rotating pair and the moving pair controlled by the torsion spring (8).

The invention discloses a six-degree-of-freedom active and passive dynamic vibration-absorbing device, which comprises a bracket and six single degree-of-freedom dynamic vibration absorbers, wherein the six single degree-of-freedom dynamic vibration absorbers are in pairwise symmetrical arrangement, and are fixedly connected with three vertical directions of the bracket via bolts respectively; and the vibration absorbers are connected with a controlled structure in two ways, namely, the vibration absorbers are connected internally and externally with the controlled structure. The bracket is ahollow metal framework connected by six crosses into a cube; each single degree-of-freedom dynamic vibration absorber comprises an end cover, a shell, a coil sleeve, a motor rotor, a diaphragm spring, an M4 nut and an M3 bolt. The six-degree-of-freedom active and passive dynamic vibration-absorbing device is installed on the surface of the controlled structure, has six-degree-of-freedom vibrationsuppression capability and active and passive control modes, is flexible and easy to control, fast in response speed and good in reliability, and is adapted to the complex vibration suppression working condition with multiple degree-of-freedom. The device has higher practical value and wide application prospect in the technical field of aviation and aerospace.

The invention relates to the technical field of thrust bearings of main shaft systems of submersible vehicles, and particularly discloses a thrust bearing device with a compact structure. A forward running end and a reverse running end adopt an asymmetric design form, an oil inlet and outlet pipe is arranged on a transition surface, and a supporting bearing bush and a forward running lantern ring adopt a conformal design; reverse running thrust blocks, forward running thrust blocks and the bush surface of the supporting bearing bush are made of a large-ratio shaft bush material, and the shell is of a high-strength steel plate welding structure, so that the overall weight, occupied size and the like of the thrust bearing can be greatly reduced, the mounting space of equipment on a submersible vehicle is saved, and the occupation of the overall weight resource of the submersible vehicle is reduced; and besides, vibration reduction cylinders are closely arranged behind an even number of the forward running thrust blocks which are evenly distributed in the circumferential direction, the vibration reduction cylinders are communicated through hydraulic pipelines and are connected with an energy accumulator structure to form a communicating device, so that the forward running thrust blocks in the circumferential direction are equal in stress, the stress can be balanced, and the situation that a single thrust block is excessively stressed and burnt due to installation and machining errors is avoided.

The invention relates to the technical field of ultra-hard materials, in particular to a hinge beam assembly and a novel synthesis press. The hinge beam assembly comprises a body, a thrust column, a small-stroke ultrahigh-pressure oil cylinder, a threaded part and a driving device. The thrust column is slidably arranged on the body along a first preset direction, the small-stroke ultrahigh-pressure oil cylinder is arranged at the front end of the thrust column, transmission and bearing connection between the body and the thrust column is formed by the threaded part, and the driving device andthe threaded part are in transmission connection. The thrust column is driven to reciprocate along a first preset direction, the small-stroke ultrahigh-pressure oil cylinder generates ultrahigh-pressure thrust, and the thrust column transmits bearing force to the body. The novel synthesis press is formed on the basis of the hinge beam assembly.

The invention relates to a high-precision clamping type telescopic system, in particular to a clamping type telescopic system which can be adjusted at high precision and can isolate external influences. The system comprises a clamping type primary mirror part, a secondary mirror part, a secondary mirror position adjusting mechanism and an external mounting mechanism. The clamping type primary mirror part comprises a primary mirror, a primary mirror fixing mechanism, a primary mirror mounting base and the like. According to the primary mirror fixing mechanism composed of the three hinges, whenan external structural part of the clamping type telescopic system shakes, the hinges of the primary mirror fixing mechanism rotate, but movement cannot be transmitted to a main machine, so that the influence of the external environment on the surface shape of the primary mirror and the position of the primary mirror can be isolated. And the secondary mirror position adjusting mechanism can precisely adjust the position of the secondary mirror by rotating the screw rod. And the external mounting mechanism adopts a cylindrical hinge mounting form, so that the influence of an external environment on the clamping type telescopic system is further isolated. The system can be applied to space cameras with clamping type telescopic requirements in spaceflight, aviation and navigation, and has theadvantages of easiness in assembly and adjustment, capability of isolating external interference and the like.

The invention relates to the field of airplane fuel oil system designing, specifically to a self-locking multifunctional gravity refill opening assembly for a mini airplane to solve the problem that a unidirectional ventilation function, oiling direction board and gravity refill opening cover can not be integrated in a conventional opening cap device and the structure of the opening cover device is complex. A sealing gasket and a wear-resistant pad are laminated with each other to ensure wear resistant performance, and a self-locking device and a gravity refill opening seat are better connected. An opening cover, a multifunctional fastening bolt, a ventilation assembly and a rubber valve are jointly form a unidirectional vent to prevent fuel oil or air in a fuel tank from flowing out of the vent. When the negative pressure of the fuel tank is great, ventilation of the fuel tank can be completed timely. The self-locking multifunctional gravity refill opening assembly is simple and delicate in structure, convenient for dismounting, and reliable in installation and sealing, the design weight is effectively reduced, and the safety of a fuel oil system is improved.

The invention discloses a towing-type vehicle and a trailer. The towing-type vehicle comprises a towing vehicle, the trailer and a vehicle controller; the towing vehicle comprises a first energy storage system; the trailer comprises a second energy storage system which is suitable for being connected with the first energy storage system and the vehicle controller under a towing mode; and under thetowing mode, the energy supply level of the second energy storage system is higher than the energy supply level of the first energy storage system. According to the towing-type trailer, a power battery system with the same high and low voltage parameters as the energy storage systems (such as a power battery system and a hydrogen fuel storage device) of the towing vehicle can be integrated on thetrailer, the driving mileage under the towing condition is increased, the operation efficiency under the trailer-free working condition is improved, and the energy utilization rate is increased, wherein the high and low voltage parameters comprise the voltage or gas pressure, communication and control strategies and the like.

Provided is a machining method of a metallurgical furnace launder. A mode that plate blank forging and machining are combined is used for machining. The method comprises the following steps that forged plate blanks are forged and pressed into a metallurgical furnace launder semi-finished product with an arc face; and a metallurgical furnace launder component semi-finished product is subjected to finish machining to form a metallurgical furnace launder finished product. The machined metallurgical furnace launder finished product comprises a launder body. The launder is formed in the top of the launder body. A plurality of cooling water channels are arranged in the launder body. The cooling water channels are communicated with each other in an end-to-tail mode. At least one water inlet and one water outlet are formed. A forming technology is changed into the mode that forging, pressing and machining are combined, so that body materials are compact, grain refining is achieved, mechanical property is good, heat conductivity is high, composite holes are used as the cooling water channels, the cooling performance of the cooling water channels is further improved, the improvements are combined so that the thickness of the launder body can be greatly reduced, a producer can know that the launder with good performance can be obtained with low cost increased, frequent maintaining or replacing is of no need, influence on normal production can be greatly reduced, and production efficiency is greatly improved.

The invention relates to a naval vessel cabin spraying and explosion suppression system. The naval vessel cabin spraying and explosion suppression system comprises a pre-warning sub system, a controlsub system and a spraying sub system; the pre-warning sub system is used for detecting the movement locus of an enemy attack weapon and sending a pre-warning signal; the control sub system is used forreceiving the pre-warning signal of the pre-warning sub system, judging the hitting part of the enemy attack weapon and sending a spraying starting instruction to the spraying sub system according toa judging result; and the spraying sub system is used for receiving the spraying starting instruction of the control sub system and starting the spraying at a corresponding part before an anti-ship weapon warhead explodes. Due to being used together the existing protection structure, the naval vessel cabin spraying and explosion suppression system can rapidly absorb explosion energy by using theliquid drop compressing, crushing, dispersing and atomizing process and the water mist heat-absorbing and gasifying process when explosion in a vessel generation cabin generates shock wave and quasi-static gas pressure load; and therefore, the strengths of the explosion shock wave and the quasi-static gas pressure are weakened and the damage degree of the cabin structure is also reduced; and correspondingly, the design weight of the structure can be reduced under the same protection grade requirement.

The invention discloses a core material structure. The core material structure comprises a main body and grooves distributed in the main body, wherein the grooves comprise at least one first groove which is formed in the first surface of the main body and extends in the length direction of the fan blade; and the at least one second groove is formed in the first surface of the main body and extends in the chordwise direction of the fan blade.

A fabrication method of a carbon nanotube shading cover comprises the following steps of (1) determining a stray light ratio elimination index of the shading cover; (2) determining the position and the size of a baffle plate inside the shading cover; (3) modeling the size, the shape and the surface diffuse reflection characteristic inside the shading cover to obtain a light ratio elimination simulation calculation result, comparing the light ratio elimination simulation calculation result with the index, and entering the next step if the requirement is met; (4) designing the shading cover and a baffle plate structure inside the shading cover which can be fixedly arranged and can stand an emission mechanical environment; (5) carrying out modal analysis on the emission mechanical environment of the designed shading cover to obtain the shading cover conforming to the mechanical performance required by emission; (6) mechanically processing the shading cover by using titanium alloy; (7) determining a growth process parameter of a carbon nanotube; and (8) growing a carbon nanotube coating layer on the inner wall of the shading cover obtained through mechanical processing, and completing fabrication. With the method disclosed by the invention, the problems of inadequate stray light elimination capability, relatively large size and relatively heavy weight of a black paint elimination shading cover can be solved.

The invention relates to a suspension support used for improving collision performance, a power assembly structure and an automobile. The suspension support comprises a first auxiliary frame mounting part, a suspension front arm and a power assembly mounting part, wherein the suspension front arm is fixedly connected between the first auxiliary frame mounting part and the power assembly mounting part, the first auxiliary frame mounting part is used for being fixedly connected to an auxiliary frame of an automobile, the power assembly mounting part is used for being fixedly connected with a power assembly of an automobile, and the suspension support is arranged to be broken at the suspension front arm when the power assembly of the automobile is extruded on the suspension front arm. The suspension support is designed into a collision fracture structure, so the suspension support is fractured when the automobile is collided, and the power assembly of the automobile is prevented from colliding and extruding an automobile body front wall structure; a problem that in the prior art, when the automobile is collided, the power assembly of the automobile extrudes a passenger compartment and seriously deforms, and passengers in the automobile are seriously collided and hurt is solved.

The invention discloses phthalimide diglycidyl ether and a preparation method thereof, which relate to a high performance resin and a preparation method thereof. The invention solves the problems that the prior high performance resin has high price or high solidification molding temperature and softening point. The phthalimide diglycidyl ether is prepared by 100 portions of diphenylmethane bismaleimide, 160 to 170 portions of furfuryl alcohol, 350 to 370 portions of epoxy chloropropane, and 20 to 25 portions of sodium hydroxide according to weight portion ratio through an addition reaction, a phthaloylation reaction and an epoxidation reaction. The solidification temperature of a product is between 160 and 170 DEG C, the epoxy value is between 0.24 and 0.31, and the softening point is between 40 and 50 DEG C. The method has rich raw material sources, a simple process, no discharge of pollutants, and low production cost, reduces the price of the product, has steady product performance, and is convenient for popularization and application. The product can produce materials with grade C insulation structures such as grade C insulation products and grade C insulation binding materials with good performance when being matched with other auxiliary materials.

The invention provides a hollow composite material paving slab. According to the invention, the periphery of the paving slab is of an L-shaped structure; two adjacent sides are of an upper L-shaped structure; other two sides are of a lower L-shaped structure; the L-shaped structure is provided with pin holes; the upper L-shaped structure and the lower L-shaped structure match with each other and fit with the pin holes; the interior of the paving slab is of a honeycomb reinforcing rib structure; and connecting members are arranged between paving slabs for solid connection. The invention has the following advantages: the hollow composite material paving slab provided by the invention has characteristics like light weight, high strength, corrosion and aging resistance, convenient installation, long service life, greenness and environmental protection; and rapid construction of places like temporary roads and working platforms under special working conditions can be realized.

The invention discloses a parallel system of 2N inverters and a control method of the parallel system. A dotted end of a coupling inductor a is connected with phases a of a first inverter and a secondinverter, the other dotted end of the coupling inductor a is connected with an input end of an independent inductor a, similarly, a coupling inductor b is connected with a coupling inductor c, outputends of same independent inductors are connected in parallel, each independent inductor is used for suppressing a ring current between the inverters, and each coupling inductor is used for suppressing a ring current in each inverter unit. On the basis of the inverter parallel systems, the control method comprises the steps of calculating a rising edge and a descending edge of switch pulse according to synchronous sawtooth carrer and a pulse phase-shift angle, and acquiring a PWM signal; and achieving control of a parallel structure of the 2N inverters by the PWM signal. The ring current of the 2N inverters is suppressed by combining advantages of the coupling inductors and the independent inductors, and expansion and control of the coupling inductor-based inverter parallel system are achieved.