58results about How to "Disengagement will not occur" patented technology

The invention provides a traverse control technology, capable of preventing the deviation and broken line of a wire rod in advance with the bigger change of the wire rod reeling spacing. A traverse device (1), reels the wire rod (3) of a reel (4) for a linear saw (2) on a traverse roller (5) and a tension roller (14), when the traverse roller (5) is the reciprocating motion along the axial direction of the reel (4), the target position of the wire rod (3) is in the right-angle direction relative to the axial direction of the reel (4) between the reel (4) and the traverse roller (5), the reference force (F1) of the wire rod (3) is detected at the tensioning roller (14), the variation force (F2) based on the displacement of the wire rod (3) deviated from the target position is detected at the traverse roller (5), based on the variation of the difference (delta F) of the reference force (F1) and the variation force (F2), the reciprocating speed (V) of the traverse roller (5) is controlled.

The invention discloses a method for improving the initial adhesive force of nylon 66 dipped tyre cord fabric. The method includes the steps of: 1) passing a non-dipped nylon 66 cord fabric through a dip solution at a speed of 50-120m / min; and 2) passing the dipped nylon 66 cord fabric through a drying area 1A, a drying area 1B, a drafting area and a shaping area in order at a speed of 50-120m / min, and then conducting packaging and storage. The dip solution is prepared by mixing 0.9-2.8 parts of resorcinol, 1.4-4.1 parts of formaldehyde, 0.1 part of caustic soda, 2.9-25.7 parts of natural latex, 8.6-51.5 parts of butadiene vinyl-pyridine rubber latex, 1.3-3.9 parts of ammonia water, and 28.9-79.2 parts of low purity water at 5-35DEG C for 5-9h. According to the invention, the dip solution greatly increases the natural latex content, the initial adhesive force of the prepared nylon 66 dipped tyre cord fabric finished product is increased to 500-1000g / 5 threads, and the production cost is low, therefore the method is easy for industrialization.

The invention belongs to the technical field of connection pieces and particularly provides an expansion bolt convenient to disassemble. The expansion bolt convenient to disassemble comprises a firstscrew cap, a first threaded rod and a first nut. The first threaded rod is fixedly installed on the bottom surface of the first screw cap and coaxial with the first screw cap. The first threaded rod is sleeved with the first nut. The bottom surface, far away from the first screw cap, of the first threaded rod is provided with a first through hole extending to the bottom surface of the first screwcap. The upper surface of the first screw cap is provided with second through holes communicating with the first through hole. A locking piece is fixedly installed on the upper surface of the first screw cap. The other end of each steel wire rope penetrates through an installation plate, the first through hole and the corresponding second through hole to be connected with the locking piece. The steel wire ropes are used for tensioning friction blocks to enable the elastic pieces to be compressed and deformed. According to the expansion bolt convenient to disassemble, through the arrangement ofthe friction blocks and the elastic pieces, the first nut is squeezed, so that locking of the bolt is achieved; a first screw is arranged to drive the steel wire ropes to move in the vertical direction so as to enable the bolt to be convenient to disassemble; and the use efficiency of the expansion bolt convenient to disassemble is improved.

The invention relates to a thin circuit protection device which comprises a hollow cavity formed by an upper shell and a lower shell, a breakable circuit consisting of a movable electrode, a movable contact, a fixed contact and a fixed electrode which are connected in series with one another, a macromolecular PTC (positive temperature coefficient) element and a bimetallic strip, wherein the upper shell consists of an upper metal insert and an upper plastic piece; reinforcement ribs are arranged on the upper metal insert, and reinforcement ribs matched with the upper plastic piece are also arranged on the upper plastic piece; the lower shell consists of a lower metal insert with a lead-out end and a fixed contact and a lower plastic piece; two clamping slots are formed in the ends, which are close to the outer wall, of two sides of the lower plastic piece; three embedding hooks are respectively arranged on a frame defined by three adjacent side edges, which are connected with the lower plastic piece, of the lower metal insert; the lower metal insert is embedded into the lower plastic piece through the embedding hooks; two bent parts are arranged at the middle section of the movable electrode along the direction perpendicular to the plane of the movable electrode; during mounting, the bent parts extend into the clamping slots of the lower plastic piece to press against the outer wall. The structural intensity of the thin circuit protection device disclosed by the invention is enhanced, and the reliability of the use of a product is improved.

The invention belongs to the field of lithium batteries, and provides a lithium battery current collector and a preparing method thereof. The lithium battery current collector comprises current collector foil and inert buffer layers applied to at least one surface of the current collector foil. Each inert buffer layer comprises coating powder and a binder, wherein the coating powder comprises at least one of metal nitride and metal carbide. The preparing method comprises the steps of dispersing the coating powder and the binder in a solvent to form inert buffer size, applying the inert buffer size to at least one surface of the current collector foil to form an inert buffer size coating, and conducting drying treatment.

The invention discloses a method for assembling lining plates of a multi-cylinder cone crusher. Moving cone lining plate installation comprises the steps that parts and tools are prepared; a movable cone lining plate falls onto a movable cone; a cutting ring is placed at the top of the movable cone; a locking bolt penetrates through the cutting ring and is screwed on the movable cone; the movablecone lining plate is centered on the movable cone and is in place; the movable cone lining plate is heated; a locking bolt is tightened; the cutting ring is welded; and epoxy resin is filled. Fixed cone lining plate installation comprises the steps that parts and tools are prepared; a fixed cone is placed on a fixed cone lining plate, so that the fixed cone lining plate and the fixed cone are centered and placed in place; a square head bolt, a spherical nut and a wedge block are installed; the spherical nut is screwed down, so that the wedge block correctly pushes against the fixed cone liningplate; whether the matching surface of the fixed cone lining plate and the fixed cone is tightly attached or not is checked; epoxy resin is filled; and a stop block and a nut lock are arranged to limit the rotation of the square head bolt and the spherical nut. According to the method, the correct, firm and reliable installation of the lining plates can be ensured; and the mounting time of the lining plates of the multi-cylinder cone crusher is saved, so that the replacement efficiency of the lining plates of the crusher is improved.

The invention provides a novel pipe joint, which has necessary and sufficient functions as a pipe joint such as for a water supply steel pipe, and simultaneously improves an application property. The pipe joint (1) provided by the invention comprises: straps (5, 5) which are welded on a part of the external circumferential surface of each connection end (4, 4) of two connected pipes (3, 3) and are used for fixing flanges; and a pair of plate-shaped flanges (6, 6) which extend along a direction parallel to a pipe shaft, and are formed at external sides of the straps (5, 5) for fixing the flanges at two positions opposite to the radial directions of the pipes, wherein connection holes (7, 7) for inserting fasteners are arranged on each flange, and the straps (5, 5) for fixing the flanges enable the pipe shafts to only extrude a specified distance to the external parts away from the end edges.

The invention discloses a power lithium battery heat dissipation mechanism which comprises a lithium battery shell and a shell cover, and the top of the lithium battery shell is movably connected with the bottom of the shell cover through a bolt. Through cooperative use of a suction fan, heat dissipation holes, a heat inductor, an induction line, a filter plate and a fixing device, when the temperature in the lithium battery shell is too high, the heat inductor operates to transmit a signal to the suction fan through the induction line, and the suction fan starts to rotate to suck external air into the lithium battery shell after receiving an instruction; hot air in the lithium battery shell can circulate to the outside through heat dissipation holes formed in the two sides, and the problems that an existing power lithium battery is in a sealed state when installed in the shell, heat of the battery is increased due to long-time operation of an electric vehicle, air in the sealed battery is violently expanded, the battery is swelled, and seriously, the battery is exploded, so that the user is easily harmed are solved.

An install arrangement of refrigerator lamp consists of a guiding plate and a lamp holder thereon. An installing hole is located on the guiding plate. Two grooves are respectively formed on the upper and lower edges of the hole. A flange is located from a side of lamp cover to a central portion on top of the screw portion in a declined way. A fixing hook is arranged at lower portion of the flange in a downward declined way. An elastic hook integrated with the holder on top of the holder with corrugated portion at its upper location to form a platform section, an upward declined section and a downward declined one. Its advantages include simple structure, easy opration, and tight installation with surface contact between the elastic hook and the lower edge of concave groove.

The invention relates to a multipurpose wrench, which comprises a shell, wherein a plurality of sleeve holes are formed on the circumferential wall of the shell towards the direction of the centre of a circle, and have different sizes. The multipurpose wrench is suitable for screwing external hexagonal screws or nuts.

Disclosed is a method that is for producing an absorbent sheet containing absorbent resin, hydrophilic fibers, and hydrophobic fibers, and that is provided with: a dehydration step for causing dehydration in the state of the abovementioned absorbent resin and the abovementioned hydrophilic fibers being in contact and containing water, resulting in a composite composition; and a sheet-forming step for heating while in the state of the abovementioned composite composition and the abovementioned hydrophobic fibers being in contact, forming a sheet shape.

The invention belongs to the technical field of bridge telescopic apparatuses, and particularly relates to a highway bridge anti-seismic telescopic apparatus. The highway bridge anti-seismic telescopic apparatus comprises supporting displacement boxes which are respectively arranged on two ends of a bridge telescopic seam, wherein a telescopic body consisting of a plurality of middle longitudinalbeams and supporting crossbeams which are connected with the middle longitudinal beams in a sliding manner is arranged between the supporting displacement boxes, the middle longitudinal beams disposedon two sides of the telescopic body are connected with the supporting displacement boxes by virtue of an edge longitudinal beam, two ends of the supporting crossbeams respectively stretch into the supporting displacement boxes and are connected by virtue of a non-directional rotating supporting seat, the non-directional rotating supporting seat is a fixed supporting seat which is arranged betweenthe supporting crossbeam and the supporting displacement box by virtue of a spherical sliding or columnar sliding, the fixed supporting seat comprises an upper supporting seat body and a lower supporting seat body with a center limiting mechanism, the limiting mechanism is arranged between the upper supporting seat body and the lower supporting seat body and consists of a center pin shaft and a receiving hole for limiting the swinging of the center pin shaft. The telescopic apparatus has the characteristics of multi-angle rotation of a bridge, seismic resistance and shock resistance and gooddamping and noise reduction effect.

The invention provides a self-grinding and self-rotating three-way reversing disc valve. A closed valve cavity is formed among an upper valve body 10, a lower valve body 1 and a middle body 3. The lower valve body 1 is provided with an inlet. The upper valve body 10 is provided with a first outlet and a second outlet. Valve seats 9 are arranged on the upper valve body 10 and the lower valve body 1 correspondingly. The valve seats are in sealed fit with upper and lower valve discs 4. The upper and lower valve discs 4 are in pressing fit on the sealing faces of the valve seats 9 through elastic supports. The center axes where the upper and lower valve discs 4 are located, the center axis where the inlet of the lower valve body 1 is located and the center axis where the first outlet in the upper valve body 10 is located do not coincide with one another, and eccentricity exists. The upper and lower valve discs 4 can achieve self-rotating around the center axes of the upper and lower valve discs 4. A sharp corner is formed at the junction of the side face and the bottom face of each valve disc (4). In the movement process of the valve, the valve discs (4) rotate around a valve rod and meanwhile achieve self-rotating around the center axes of the valve discs (4), the sealing faces are constantly ground and polished, and the service life of the valve is prolonged. In the valve reversing process, the sharp-edge valve discs (4) constantly scrape foreign matter on the sealing faces, the situation that particle media enter the sealing faces to cause damage is avoided, and the service life of the valve is prolonged.

The present invention relates to a ceria-carbon-sulfur (CeO2-C-S) composite, a method for preparing the same, and a positive electrode for a lithium-sulfur battery and the lithium-sulfur battery comprising the same. The composite comprise a ceria-carbon (CeO2-C) composite in which cylindrical carbon materials having ceria (CeO2) particles bonded to the surface thereof are intertwined and interconnected in three dimensions; and sulfur introduced into at least a part of the outer surface and the interior of the ceria-carbon composite.

The invention provides sticky controllable adhesive tape and an application method thereof. The sticky controllable adhesive tape at least comprises a base film and an adhesive layer, wherein the surface of the base film at least comprises the adhesive layer, the adhesive layer initially has no adhesive force at room temperature, when the temperature is raised to 70-95 DEG C, the adhesive layer produces a matching adhesive force, and when the temperature is adjusted to a specific temperature in a temperature range other than 70-95 DEG C, the adhesive force is reduced. The adhesive layer initially does not need to cover a release film at room temperature. When heated to 70-90 DEG C, the adhesive layer produces the matching adhesive force, so that the processing accuracy of ceramic lamination and cutting process is ensured. The lamination is completed and cooled to the room temperature, the adhesive tape still has sufficient adhesive force for ceramic lamination, so as to ensure that multi-layer ceramic lamination and the adhesive tape cannot be subjected to displacement and detachment in the process of transfer and transportation, after cutting is completed, heating is carried out to a specific temperature, the adhesive force between the adhesive tape and ceramic pieces is greatly reduced, and the ceramic pieces can be easily picked up from the adhesive tape. The temperature sensitive adhesive is very suitable for lamination and cutting of ceramic capacitors.

The invention discloses modeling construction equipment for landscaping, which comprises a machine shell, a diesel engine body is arranged in the machine shell, a sawtooth chain frame is arranged at the bottom end of the machine shell, one end of the diesel engine body is connected with an output shaft, a transmission sleeve is fixed to one end of the output shaft, a transmission block and a transmission column are arranged in the transmission sleeve, the transmission block is located at one end of the transmission column, and inclined surfaces with the same inclination are arranged on the adjacent surfaces of the transmission column and the transmission block. The transmission block, the transmission sleeve and the transmission column are designed, the transmission block and the transmission column are assembled in the transmission sleeve, the transmission block is driven by the transmission sleeve to rotate, at the moment, the adjacent surfaces of the transmission block and the transmission column are attached to each other to achieve synchronous transmission, at the moment, the inclined surfaces between the transmission column and the transmission block mutually extrude to push the transmission block to slide upwards, so that separation is generated, power transmission is stopped in time, and tooth pieces are prevented from being damaged.

The present invention provides a circuit substrate and a circuit-formed suspension substrate comprising the circuit substrate, the circuit substrate comprising a metal foil substrate and an insulating layer composed of a polyimide resin formed on the metal foil substrate, wherein the polyimide resin is one obtained by the reaction of (A) p-phenylene diamine and (B) acid anhydrides of (a) 3,4,3',4'-biphenyltetracarboxylic acid dianhydride and (b) 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane. Since a coefficient of linear thermal expansion of the polyimide resin is close to that of various metal foils, the circuit substrate causes no cracking on the resin layer and scarcely causes warpage, and the resin layer does not separate.

The invention provides a current collector and a preparation method thereof. The current collector comprises a current collector foil and at least one surface of the current collector foil is coated with coating layers containing graphene and a binder. The preparation method comprises the following steps of dispersing graphene and the binder in a solvent to obtain slurry, coating the slurry on at least one surface of the current collector foil and drying. Graphene of the coating layer has a two-dimensional sheet structure and thus the graphene forms a uniform and compact coating on the surface of the current collector foil so that a contact area of the graphene and the surface of the current collector is greatly improved; a conductive contact between an active material and the current collector is improved; the interface resistance of the current collector and the active material is effectively reduced; and internal resistance of a cell is reduced. Contact areas of graphene layers paved on the surface of the current collector and contact areas of the graphene layers and the current collector are large and thus interactional forces are strong; falling off is difficult; adhesive forces are strong; separation of the active material and the current collector is avoided in charging and discharging; and internal resistance reduction is promoted.

The invention discloses a coating waste liquid solid-liquid separation device, and belongs to the technical field of waste liquid treatment. The coating waste liquid solid-liquid separation device comprises a separation tank, a water inlet tank is fixedly connected to the upper portion of the separation tank, an inclined plate is fixedly connected to one side of the separation tank, baffles are arranged on the two sides of the inclined plate, and an impurity discharging tank is fixedly connected to the bottom end of the inclined plate; an opening is arranged at one end of the impurity discharging tank, a first rotating shaft is rotatably connected in the water inlet tank, a plurality of blades are fixedly connected to the outer wall of the first rotating shaft, a water inlet platform is arranged at the top of the water inlet tank and is communicated with the interior of the water inlet tank through a water inlet, the water inlet is formed in one side of the first rotating shaft, a water falling opening is formed in the bottom of the water inlet tank, and one end of the first rotating shaft extends out of the water inlet groove and is fixedly connected with a speed changing assembly. According to the separation device, continuous separation work of a large amount of waste liquid can be met, separated impurities are automatically pushed into the collecting box, follow-up centralized treatment is facilitated, electric drive is not needed, electric energy is saved, and the earlier-stage investment cost is reduced.

The invention belongs to the technical field of energy-saving building materials, and particularly discloses a building energy-saving wall enclosure OSB cladding structure insulation board. The cladding structure insulation board comprises an XPS core board, an upper surface board arranged on one side of the XPS core board and a lower surface board arranged on the other side of the XPS core board,wherein an upper cladding board is arranged between the XPS core board and the upper surface board, a lower cladding board is arranged between the XPS core board and the lower surface board, the upper cladding board and the lower cladding board are OSB boards, he upper surface board and the lower surface board are light calcium silicate boards, and the boards are bonded through a single-componentreactive polyurethane adhesive. The cladding structure insulation board has the characteristics of high efficiency, energy conservation, moisture resistance, water resistance, fire prevention, good sound insulation, simple structure, convenience in production, manufacturing, use and installation and long service life, and has a very good market application prospect.

The invention relates to the technical field of filling devices, and discloses a ceramic filling device with the high intelligent degree. The ceramic filling device comprises a ceramic pump body, a ceramic piston, a telescopic block and a ceramic shaft sleeve, the outer side of the ceramic pump body is fixedly sleeved with a matched protective sleeve, and a piston rod of the ceramic pump body is in threaded connection with the ceramic piston; the piston rod of the ceramic pump body is fixedly sleeved with a fixing ring, a locking mechanism is installed between the fixing ring and the ceramic piston, a guide pipe is fixedly inlaid in the center of the top of the protective sleeve, a matched threaded rod is movably inserted in the guide pipe, and the bottom end of the threaded rod penetratesthrough the guide pipe, extends downwards and is fixedly connected with the telescopic block; and the telescopic block is movably connected with the protective sleeve, the ceramic shaft sleeve is fixedly installed in the center of the lower surface of the telescopic block, and sliding grooves are symmetrically formed in the inner wall of the guide pipe. According to the ceramic filling device with the high intelligent degree, the telescopic block can be conveniently adjusted and controlled to ascend and descend, and the ceramic piston can be conveniently disassembled, assembled and replaced according to needs.

The invention discloses leather cutting equipment for bag manufacturing. The leather cutting equipment structurally comprises supporting stand columns, spreading and stretching mechanisms, an operation platform, a first limiting rod, a knife rest, a second limiting rod, spreading inlets, an operation button, heat dissipation openings, a machine body and an operation panel, wherein the operation platform is fixedly arranged at the top end of the machine body, and the spreading and stretching mechanisms are mounted on the two sides of the operation platform correspondingly; the spreading inletsare formed in one sides of the spreading and stretching mechanisms, and the heat dissipation openings are formed in the machine body and located below the spreading inlets; and the operation panel isarranged beside the operation platform. The spreading and stretching mechanisms and a pressing mechanism are combined to solve the problems that when the thickness of leather is not uniform, leather is too thick or too thin, folding and displacement are caused in the spreading process, and consequently errors occur in cutting of the next procedure and produced bags cannot reach the national standard; and round plastic clamping teeth are adopted for pressing, so that attractiveness of the leather is prevented from being damaged by scratches on the leather.

A rapid plug assembly comprises a copper bar female end, wherein at least one connector female end is arranged on the copper bar female end, the connector female end comprises a spring sheet frame, spring sheet bars are respectively arranged on two surfaces, opposite to each other, of the spring sheet spring, and each spring sheet bar comprises a plurality of contact strips parallel to one another. Such the copper bar female end is not liable to loose when inserted into a component, and is more stable to connect.

The invention relates to the technical field of automobile steering transmission, and discloses an offset collision steering wheel anti-deviation transmission device. A shaft hole is opened at a position in the middle through one side of the left clamping plate, and a shaft hole is movably socketed inside the shaft hole. For the reversing gear, one side of the reversing gear is movably socketed with the right clamping plate, and the outer surface of the reversing gear is in contact with the driving gear and the driven gear and is in a mutual meshing relationship. The driving shaft and the driven shaft are arranged in a mutually dislocated manner, and the reversing gear, the driving gear and the driven gear are meshed with each other for transmission, so as to realize the transmission effect of the original cardan shaft, and the front of the car is severely damaged due to impact. When the time is shortened, the driving shaft and the driven shaft that are misaligned with each other cannot transmit the impact generated by the impact to the steering wheel, thereby preventing the cardan shaft in the original device from transmitting the impact to the steering wheel during the impact, causing the steering wheel to deviate and causing the airbag to fail. Catch the problem of the head and improve the safety performance of the device.

The invention provides an electric ground cleaning machine which comprises a moving device, a sweeping device and the trash can bearing device. The trash can bearing device comprises a horizontal bearing frame, a vertical bearing frame, a positioning frame, a vertical telescopic rod and a horizontal telescopic rod. The bottom wall of the horizontal bearing frame is provided with a first sliding groove, the bottom wall of the vertical bearing frame is provided with a second sliding groove, the first sliding groove is matched with the second sliding groove, the two sides of the vertical bearing frame are provided with antifriction bearings, the positioning frame comprises guide rails fixedly connected to the moving device, the antifriction bearings are arranged in the guide rails, the vertical telescopic rod is connected between the moving device and the vertical bearing frame, and the horizontal telescopic rod is connected between the horizontal bearing frame and the vertical bearing frame. Ascending, descending, stretching and retraction of the bearing frames are controlled through the telescopic rods, the horizontal bearing frame which bears a trash can is closer to the ground when unloading the trash can, a user can conveniently draw out or install the trash can through the stretching and retraction movement, and the user can unload and install the trash can conveniently.

The invention belongs to the technical field of connection pieces and particularly provides an expansion bolt convenient to disassemble. The expansion bolt convenient to disassemble comprises a firstscrew cap, a first threaded rod and a first nut. The first threaded rod is fixedly installed on the bottom surface of the first screw cap and coaxial with the first screw cap. The first threaded rod is sleeved with the first nut. The bottom surface, far away from the first screw cap, of the first threaded rod is provided with a first through hole extending to the bottom surface of the first screwcap. The upper surface of the first screw cap is provided with second through holes communicating with the first through hole. A locking piece is fixedly installed on the upper surface of the first screw cap. The other end of each steel wire rope penetrates through an installation plate, the first through hole and the corresponding second through hole to be connected with the locking piece. The steel wire ropes are used for tensioning friction blocks to enable the elastic pieces to be compressed and deformed. According to the expansion bolt convenient to disassemble, through the arrangement ofthe friction blocks and the elastic pieces, the first nut is squeezed, so that locking of the bolt is achieved; a first screw is arranged to drive the steel wire ropes to move in the vertical direction so as to enable the bolt to be convenient to disassemble; and the use efficiency of the expansion bolt convenient to disassemble is improved.

The invention discloses a method for improving the initial adhesive force of nylon 66 dipped tyre cord fabric. The method includes the steps of: 1) passing a non-dipped nylon 66 cord fabric through a dip solution at a speed of 50-120m / min; and 2) passing the dipped nylon 66 cord fabric through a drying area 1A, a drying area 1B, a drafting area and a shaping area in order at a speed of 50-120m / min, and then conducting packaging and storage. The dip solution is prepared by mixing 0.9-2.8 parts of resorcinol, 1.4-4.1 parts of formaldehyde, 0.1 part of caustic soda, 2.9-25.7 parts of natural latex, 8.6-51.5 parts of butadiene vinyl-pyridine rubber latex, 1.3-3.9 parts of ammonia water, and 28.9-79.2 parts of low purity water at 5-35DEG C for 5-9h. According to the invention, the dip solution greatly increases the natural latex content, the initial adhesive force of the prepared nylon 66 dipped tyre cord fabric finished product is increased to 500-1000g / 5 threads, and the production cost is low, therefore the method is easy for industrialization.

The invention provides a micro-current signal transmission connector for a sensor, and belongs to the technical field of high-precision sensors. The micro-current signal transmission connector comprises: supporting legs, wherein the bottom ends of the supporting legs are fixedly connected to a conductive layer of a fixed polar plate; a limiting ring; and elastic sheets, wherein the diameter of theminimum circumference defined by the extending sections of the elastic sheets is smaller than that of the circumference of the limiting ring. According to the invention, the micro-current signal transmission connector is matched with the conductive column core in an inserting manner, so that in the installation process of the conductive column core, the micro-current signal transmission connectoris not separated from the conductive column core; and the connector is fixedly connected to the female component through the supporting legs to limit the conductive column core, so that the relativeposition of the connector and the fixed polar plate is fixed, and virtual connection or open circuit is avoided.