529 results about "Convex structure" patented technology

The invention discloses a special cable for a complex environment and a preparation method of the special cable. The special cable comprises a cable core, a composite protection layer, an armor layer and an outer coating layer, the composite protective layer comprises an inner sheath layer, a middle reinforcing layer and an outer sheath layer; the armor layer is formed by wrapping a metal belt, the inner side of the armor layer is provided with a continuous bulge structure, and the continuous bulge structure is embedded with the spiral grooves in the surface of the outer sheath layer to form mechanical interlocking, so that displacement and looseness of the armor layer are effectively prevented; the reinforcing core body is embedded in the groove in the outer side of the metal belt, and the reinforcing core body and the metal belt are fixed through the spring piece, so that reinforcing buffering is formed, the anti-fatigue and anti-impact performance is remarkably improved, and the cable is suitable for complex working conditions of dynamic bending, torsion and frequent vibration, such as ocean cables, trailing cables and robot cables. The device has the advantages of being stable in structure, high in fatigue resistance and long in service life. The preparation method comprises the steps of spiral groove processing, metal belt pre-forming, reinforcing core inlaying, spring piece fixing, wrapping and armoring and the like, the process is reliable, and the method is suitable for large-scale production.

The utility model relates to the technical field of oil field underground oil extraction tools, and discloses a deep well fracturing packer rubber sleeve, which comprises an outer layer flexible sealing ring, an inner layer flexible sealing ring, an inner layer flexible sealing ring and an outer layer flexible sealing ring, and the outer layer flexible sealing ring is used for adapting to the surface of a well wall and realizing sealing; the middle composite buffer layer is used for buffering external pressure and absorbing stress generated by expansion; the inner-layer rigid supporting framework is used for providing structural support and limiting the expansion range of the rubber sleeve; the outer layer flexible sealing ring is of a gradient type flexible protruding structure. According to the utility model, the outer-layer flexible sealing ring adapts to an irregular well wall and realizes tight sealing through a gradient structure and micro lines, the middle composite buffer layer absorbs external pressure and disperses expansion stress, the anti-fatigue capability of the rubber sleeve is enhanced, and the inner-layer rigid supporting framework controls deformation through the supporting ribs and the compensation grooves; and the long-term stability of the rubber sleeve under high-pressure and high-temperature conditions is ensured.

The utility model discloses heat insulation type laminated iron, which comprises a metal substrate and a PET (polyethylene terephthalate) layer adhered on the surface of the metal substrate, the PET layer comprises a base layer and a conical array structure formed on the surface of the base layer, the conical array structure comprises a plurality of conical convex structures, and an Ag layer and an oxide protection layer are sequentially arranged on the side surface of each conical convex structure. According to the laminated iron, the reflectivity of the laminated iron in an infrared band can be improved, the heat insulation performance of a material is enhanced, meanwhile, the risk of migration of harmful substances is avoided, and the laminated iron has good safety.

The utility model discloses a correction component which comprises a first protruding structure arranged corresponding to the lip-cheek side or the tongue side of a first tooth jaw, and the first protruding structure is configured in the mode that when the first protruding structure abuts against a second tooth jaw of a pair jaw, a first jaw position is formed, the first jaw position deviates from an initial jaw position, and when the first jaw position deviates from the initial jaw position, the second jaw position deviates from the initial jaw position. The first occlusal force corresponding to the first jaw position is greater than the initial occlusal force corresponding to the initial jaw position. According to the utility model, the first jaw position can be reached through the mutual abutting of the first convex structure and the second tooth jaw, and the first jaw position has larger first occlusal force, so that larger orthodontic force can be provided for the first tooth jaw and the second tooth jaw.

The utility model provides a nested type grinding roller structure which comprises an assembling layer, a connecting layer and a grinding layer which are sequentially arranged in an annular nested mode from inside to outside, and concave-convex structures in the horizontal direction and the vertical direction are arranged on the outer surfaces of the assembling layer and the connecting layer respectively. The minimum inner diameter of the inner surface of the grinding layer is larger than the maximum inner diameter of the outer surface of the assembly layer. Cheap carbon steel is used in the inner layer, high-chromium alloy with high cost is used in the outer layer, and the problems of high cost, waste of raw materials and the like in the abrasion replacement process due to the fact that the whole body is cast by using the high-chromium alloy are solved; after the fixing of the assembly layer and the grinding layer is removed, the assembly layer can be taken out from the axial direction and replaced with a new grinding layer, so that a new assembly layer does not need to be cast again, the processing time of a new product is saved, the replacement efficiency is improved, and meanwhile, the cost is reduced to a certain extent by repeatedly using the assembly layer.

The utility model relates to the technical field of steam power generation turbines, in particular to a mixed flow type saturated steam power generation turbine which comprises a cylinder, the cylinder comprises a vertical inlet cavity and a horizontal outlet cavity which are communicated, and reinforcing ribs are arranged at the positions, corresponding to the joint of the two cavities, of the inner wall of the cylinder. A protruding structure at the bottom of the side, away from the horizontal outlet cavity, of the outer wall of the air cylinder is fixedly connected with a gearbox. The stationary blade assembly comprises a first-stage radial flow stationary blade fixedly arranged on the inner wall of the vertical inlet cavity and a second-stage axial flow stationary blade fixedly arranged on the reinforcing ribs; the rotor assembly comprises a rotating part connected with the high-speed shaft of the gear box, a first-stage radial flow vane impeller and a second-stage axial flow vane impeller, wherein the periphery of the rotating part is sleeved with the first-stage radial flow vane impeller and the second-stage axial flow vane impeller. The radial flow turbine and the axial flow turbine are combined to form the mixed-flow turbine, so that the working capacity of a single cylinder is improved, the power generation efficiency is improved, the cost is saved, and the unit size is reduced.

The utility model discloses a quick repair pavement patch for municipal engineering, and particularly relates to the technical field of road maintenance, the quick repair pavement patch comprises a pavement, a patch assembly and an adjusting assembly, and the patch assembly and the adjusting assembly are placed above the pavement; the patch assembly comprises a limiting groove plate, a mold plate and an insertion rod. Through the synergistic effect of the patch assembly and the adjusting assembly, the inserting rods are evenly inserted into asphalt filler in the vibration tamping process, vibration tamping is accelerated, air is exhausted, dense distribution is ensured, and the bearing capacity and durability of a road surface are improved; after the assembly is removed, a concave-convex structure is formed on the asphalt surface, the heat dissipation area is increased to accelerate the cooling speed, meanwhile, the anti-skid performance is remarkably enhanced by improving the roughness, and the driving safety in rainy days is guaranteed. In addition, the sliding design of the adjusting assembly can flexibly adjust the overlapping range of the first rectangular groove and the second rectangular groove, the size of the surface protruding block is controlled, the antiskid requirements of different traffic scenes are met, and the universality and adaptability of the device are enhanced.

The utility model discloses a pressure stabilizing cover, relates to the technical field of pressure stabilization, and aims to solve the technical problem that the sealing effect needs to be improved when air pressure is balanced through a cross curve. The bottle cap comprises a cap body capable of being connected with a bottle body, the cap body is respectively provided with a first through hole for containing an air pressure balancing device and a second through hole for containing a material guide pipe, the air pressure balancing device comprises an elastic film, the elastic film comprises a plurality of elastic blocks which are in contact with one another, and a concave-convex structure is arranged at the contact position of every two adjacent elastic blocks. The multiple elastic blocks making contact with one another form a blocking structure for blocking the first through hole through the concave-convex structure. The bottom plate, the top plate and the like are adopted, so that the sealing degree of the bottle body can be improved, and the stability of the device in use can be improved.

The application provides a kind of ice constant temperature dynamic mechanical property testing device, belongs to ice detection technical field, including launch subassembly, impact lever, incident support, incident lever, sample support, transmission support, transmission lever, data acquisition module and data processing module, the end face of impact lever towards incident lever is equipped with several spaced convex structures, the end face of incident lever towards impact lever is equipped with shaping piece, shaping piece is used to extend the rising time of incident stress wave that incident lever transmits to ice sample, the end face of incident lever towards ice sample is equipped with wave modulation module, wave modulation module is used to realize the wave impedance continuous gradient matching of incident stress wave from incident lever to ice sample, data processing module corrects the data collected by data acquisition module to obtain final incident wave strain and final transmission wave strain, and calculates the strain rate, stress and strain of ice sample.The application scheme improves the accuracy of ice constant temperature dynamic mechanical property test results.

The application discloses a backlight module and a display device, and belongs to the technical field of display. The backlight module provided by the application comprises a shell, a lamp plate and an optical film material. The shell is provided with a plurality of convex structures on the side of the bottom plate facing the light transmission opening. The convex structures are used for supporting the optical film material, thereby supporting the light mixing distance between the optical film material and the lamp plate. The height of the convex structures can be flexibly adjusted according to the light mixing distance. Since the convex structures and the shell can be formed simultaneously by one-stroke stamping process, or the convex structures and the shell are fixedly connected through connecting pieces, the firmness of the connection between the convex structures and the shell can be ensured. Therefore, the convex structures can replace the inner glue frame, the cost is reduced, and the reliability of the backlight module is improved.

The utility model discloses a kind of general carriers suitable for a variety of special-shaped PCB mounting, belong to PCB mounting carrier technical field, including shell, the inside fixed connection of shell has carrier plate, by the carrier plate in shell forms storage space, phase-change medium is placed in the storage space;Through the solid-liquid phase change characteristic of phase-change medium, temperature control is carried out with heating coil, can make supporting component with PCB shape dynamic adjustment deployment position and height, after melting, phase-change medium allows supporting component free displacement, after cooling solidification forms stable support structure, can perfectly adapt to different curvature, concave-convex structure special-shaped PCB, solve the problem that magnetic attraction is not stable, easily affect production, the control mechanism set with heating and cooling two modes, phase-change medium can be quickly melted by heating coil, then cooling water circulation is driven by miniature pump body, can be quickly completed medium solidification, simple and convenient to use, and adjustment speed is fast.

The invention relates to the technical field of aero-engine gas flow path sealing, and discloses a labyrinth type multi-stage brush type sealing device which comprises a rotor runway and a multi-stage brush type sealing structure. The rotor runway comprises a plurality of convex parts and a plurality of concave parts, and the convex parts and the concave parts are sequentially and alternately connected in the first direction to form a concave-convex structure; the multi-stage brush type sealing structure comprises a plurality of brush type sealing units, part of the brush type sealing units abut against the protruding parts, and part of the brush type sealing units abut against the concave parts. The multi-stage brush type sealing is arranged, so that the pressure resistance of the sealing device is improved; and meanwhile, the rotor runway forms a concave-convex structure through sequentially and alternately connecting a plurality of convex parts and a plurality of concave parts, and is matched with a multi-stage brush type sealing structure to form a labyrinth sealing effect, so that double sealing is formed, a leakage flow path is increased, leakage energy loss is effectively increased, the leakage amount is greatly reduced, and the sealing performance of the whole device is improved.

The invention relates to the field of clothes treatment equipment, in particular to a protruding structure of a door, the door and the clothes treatment equipment, and aims to solve the problem of water leakage possibly caused when water enters the existing clothes treatment equipment. In order to achieve the purpose, the clothes processing equipment comprises an outer barrel, an inner barrel and a door, the inner barrel is rotatably arranged on the inner side of the outer barrel, and a gap is formed between an inner barrel opening of the inner barrel and an outer barrel opening of the outer barrel; the end face of the protruding structure of the door faces the inner side of the inner barrel, the end face is closer to the inner side of the inner barrel than the gap, a water outlet is formed in the end face, a water inlet channel structure is arranged on the door, and the water inlet channel structure guides a water source into the inner barrel through the water outlet. According to the scheme, after entering the water inlet passage structure, a water source flows out through the water outlet in the end face, and the end face faces the inner side of the inner barrel and is closer to the inner side of the inner barrel than the gap, so that water flowing out of the water outlet directly flows to the inner side of the inner barrel and cannot be leaked into the gap.

The invention relates to the technical field of automobile door systems, in particular to a square step flange piece blank cold heading process for an automobile door system. The method is applied to a square step flange piece cold heading blank, and the flange piece cold heading blank comprises a cold heading blank body of an inverted convex structure. Size-variable clamping grooves are formed in the two ends of the blank; the method further comprises the following steps that S1, shearing and blanking are conducted, specifically, a cylindrical blank accurate in length and size is cut from the wire rod wire; s2, upsetting is conducted, specifically, multiple stations are adopted, segmented upsetting is conducted in sequence, the cylindrical blank is upset into a conical blank, and preparation is made for forming an inverted convex structure; s3, flange preforming is conducted, specifically, the conical blank is subjected to cold heading to form a blank of an inverted convex structure through a shape mold; and S4, final shaping is conducted, specifically, final coining is conducted on the blank of the inverted convex structure, and tiny fillets or radian errors of the previous procedure are eliminated. Through cooperation of multi-station segmented upsetting, pre-forming and final shaping, near-net forming of the square step flange piece blank is achieved, and consumption of raw materials is greatly reduced.

A knob type locking buckle comprises a middle shaft sleeve, a clamping groove end piece and a clamp end piece, the clamping groove end piece and the clamp end piece are correspondingly arranged at the two ends of the middle shaft sleeve respectively and inserted into the middle shaft sleeve to be in butt joint with a lock catch, a clamping groove is formed in the end of the clamping groove end piece, a spirally-coiled sliding groove is formed in the circumferential wall of the clamping groove end piece, and a protruding column corresponding to the spirally-coiled sliding groove is arranged on the inner wall of the middle shaft sleeve. When the clamping groove end piece is inserted into the middle shaft sleeve, the protruding column on the inner wall of the middle shaft sleeve is clamped into the sliding groove to limit the limiting position where the clamping groove end piece extends out of the middle shaft sleeve to be exposed out of the clamping groove and retreat from the middle shaft sleeve, and the end, facing the middle shaft sleeve, of the clamp end piece is provided with a clamping end structure clamped into the clamping groove. According to the knob type locking buckle disclosed by the utility model, the clamping groove end piece can be switched between two different states of exposing the clamping groove part and folding and shielding the clamping groove part through the rotary progressive sliding groove and the bulge structure, so that the matched clip end piece is clamped into the clamping groove to realize opening and closing of a jewelry rope chain, and the knob type locking buckle is simple in structure and convenient to use. Fatigue failure is effectively prevented, and connection is stable and reliable. And the product quality and the use experience are improved.

The ventilation device comprises a shell, a cold and hot module, an air inlet baffle, an air outlet baffle, a shifting rod, a rotating disc and an elastic piece, an air channel is formed in the shell, one end of the air channel is provided with a hot air inlet and a cold air inlet which are arranged up and down, and the other end of the air channel is provided with a first air outlet and a second air outlet which are arranged left and right; the air inlet baffle can be turned up and down to open the hot air inlet or the cold air inlet, the air outlet baffle can be turned left and right to open the first air outlet or the second air outlet, the shifting rod is provided with an abutting portion, and the rotating disc is provided with a concave-convex structure and can rotate to drive the air outlet baffle to be turned over through the second transmission structure. Meanwhile, the abutting part movably abuts against the concave-convex structure to enable the deflector rod to swing up and down, and the deflector rod drives the air inlet baffle to turn over through the first transmission structure. The air inlet baffle and the air outlet baffle are simultaneously driven by the rotary table, switching of cold and hot air and switching of the left and right air outlets can be controlled only by driving the rotary table, the number of action mechanisms is small, the structure is compact, and control is easy.

The application relates to the technical field of injection molding and discloses a rapid-forming automobile key precision injection mold and a processing method, which comprise a movable mold and a fixed mold, the upper portion of the movable mold is provided with a stirring device, the stirring device stirs and injects raw materials, and the raw materials are injected into the movable mold; the upper portion of the stirring device is provided with a top plate, a pushing motor is installed at the center position of the top plate, and the pushing motor is used for pushing the stirring device and the movable mold to move up and down; the bottom portion of the fixed mold is provided with a cooling tank, the fixed mold is placed on the cooling tank, and cooling liquid is injected into the cooling tank; the fixed mold is composed of two lower molds, two positioning plates and a supporting plate, the bottom portion of the supporting plate is fixedly installed with a stand column, the stand column is fixedly installed in the cooling tank and is used for supporting the supporting plate, the middle portion of the lower mold is designed as a convex block, the two convex blocks and the supporting plate form a convex structure, the bottom portion of the movable mold is designed as a concave structure, the convex structure and the concave structure form a mold cavity, and the mold cavity is used for automobile key precision injection molding.

The utility model discloses a vehicle mattress, which comprises a first inflating body, a second inflating body and a third inflating body, the first inflating body comprises a concave-convex structure, the concave-convex structure is positioned at the bottom of the first inflating body and used for being matched with a concave-convex part of a vehicle seat, and the concave-convex structure is matched with the concave-convex part in a concave-convex manner; and the second inflating body is positioned above the first inflating body. The mattress can be attached to concave and convex parts of positions such as a vehicle seat and the like, so that the mattress has good stability when in use, and the use experience of a user can be improved.

The utility model discloses an anti-slipping structure capable of preventing a main line locking bean from slipping, and belongs to the technical field of fishing tackles. The structure is arranged on the outer surface of a main line protection rope, the main line protection rope wraps the upper end of a main line for a certain length, the upper end of the main line is fixed to the tip of a fishing rod in a knotting mode, and a locking bean is arranged outside the protection rope in a sleeving mode and used for limiting the knotted portion. The anti-disengaging structure is a protruding structure arranged below the locking bean and can provide mechanical stopping when the locking bean slides. The protruding structure can be formed in the modes of sleeving an elastic sleeve, performing thermal shrinkage forming, bonding a prefabricated part, winding a flexible material or dispensing curable colloid and the like. The structure effectively prevents the locking bean from sliding downwards in the operation or throwing process, guarantees the stability and the use safety of a fishing tackle combination, and is suitable for various fishing tackle combination forms.

The invention belongs to the technical field of hydraulic equipment, and particularly discloses a small-table-board ultrahigh-pressure hydraulic extrusion press which comprises a hydraulic system, an electrical system, a supercharger and a hydraulic body. The hydraulic body comprises a rack, a liquid filling device, an upper cross beam, a main cylinder, a return cylinder, an abutting mechanism, a pressing head and a workbench. The pressurizer is used for pressurizing liquid of the hydraulic system and conveying the liquid into the liquid filling device; a big-end-down stepped hole is formed in the rack; a cylinder body of the main cylinder is of a big-end-down protruding structure, a through hole matched with the small end of the cylinder body is formed in the upper cross beam, and the small end of the cylinder body of the main cylinder is embedded into the through hole. The periphery of the upper cross beam is fixed in a small hole of the stepped hole; the cylinder body large end of the main cylinder is matched with the large hole of the stepped hole, and the upper side of the cylinder body large end can abut against the top of the large hole of the stepped hole; the abutting mechanism can jack up the main cylinder upwards. And the return cylinder is mounted on the main cylinder. The pressurizer is adopted to provide ultrahigh pressure, the use pressure is improved, the cylinder diameter of the main cylinder is reduced, and the device is more suitable for large-tonnage small table tops.

The utility model relates to a kind of for solid medicine's grinding medicine injection device, comprising: vertically arranged cylinder;Cylinder cover, the cylinder cover is with the cylinder with detachable way be connected together by rotating connecting mechanism, the cylinder and the cylinder cover are configured to form grinding chamber for receiving solid medicine in their inside, the top of the grinding chamber is formed with the feed inlet for receiving the solid medicine, and its two sides are formed with the input port for receiving liquid and the output port for discharging liquid respectively;Wherein, the bottom surface of the cylinder cover is configured with grinding assembly, the grinding assembly includes axially arranged needle, the cutting blade group around the needle arrangement and multiple convex structures distributed between the cutting blade group.The utility model also relates to a kind of medicine injection system, to improve grinding efficiency, while realizing grinding-mixing-infusion whole-process closed operation.

The utility model provides a gear ring mounting structure and a gear box. The gear ring mounting structure comprises a gear ring mounting piece. The supporting ring and the gear ring mounting piece are mounted in a circumferential anti-torsion manner; the gear ring is installed on the gear ring installation piece in a circumferential direction and anti-torque mode through a supporting ring, a concave-convex structure is formed on the circumferential wall of the supporting ring in the circumferential direction of the supporting ring, and an inner circumferential concave portion located on the inner circumferential wall and an outer circumferential convex portion located on the outer circumferential wall are formed on the portion, integrally deformed towards the radial outer side, of the circumferential wall of the supporting ring. An inner peripheral convex part located on the inner peripheral wall and an outer peripheral concave part located on the outer peripheral wall are formed on the portion, integrally deformed towards the radial inner side, of the peripheral wall of the supporting ring, a spline is arranged on the periphery of the gear ring, and the spline is matched with the inner peripheral concave part, so that the gear ring and the supporting ring are installed in a circumferential anti-torque mode. And an accommodating space is formed between the peripheral concave part and the gear ring mounting piece.

The invention relates to the technical field of tire production, and discloses a blocky pattern tire tread and a pneumatic tire, the blocky pattern tire tread comprises a plurality of blocky patterns, at least the blocky patterns in contact with the ground form tread textures, the tread textures form at least one group of concave-convex structures for dividing the blocky patterns, the concave-convex structures extend along the surfaces of the blocky patterns through grooves, and the grooves extend along the surfaces of the blocky patterns. And the depth H1 of the groove is greater than or equal to 0.2 mm and less than or equal to 2mm. According to the invention, a plurality of groups of concave-convex structures are formed to divide the surface layer of the block-shaped patterns, so that the hardness of the surface layer is reduced under the condition that regular arrangement of the block-shaped patterns on the tread is not damaged, the absorption of impact energy when the tire is in contact with the ground is improved, and the noise in the tire running process is reduced; and therefore, the tire can comprehensively consider the driving performance, the wetland drainage performance and the low-noise requirement.

The utility model discloses a quick mounting and connecting assembly for a marine environment monitoring sensor, and belongs to the technical field of marine environment monitoring sensor mounting. A quick mounting and connecting assembly for a marine environment monitoring sensor comprises a mounting seat fixedly connected to the bottom end of a marine buoy body, the bottom end of the mounting seat is provided with an insertion groove with the vertical section of an inverted-convex structure, and an insertion plate with the vertical section of an inverted-convex structure is movably inserted into the insertion groove. According to the quick mounting and connecting assembly for the marine environment monitoring sensor, when the quick mounting and connecting assembly for the marine environment monitoring sensor is used and the water quality monitoring sensor needs to be dismounted and overhauled, the clamping plate can be manually pushed to compress the two S-shaped elastic sheets, and meanwhile, one end, far away from the clamping plate, of the clamping block continues to go deep into the bayonet; at the moment, the distance between the second arc-shaped clamping opening and the first arc-shaped clamping opening is enlarged, the signal line can be conveniently taken out, then under the rebound effect of the S-shaped elastic piece, the clamping plate rebounds and moves rightwards to be attached to the inner wall of the right side of the line plugging groove, and at the moment, the end, away from the clamping plate, of the clamping block is completely pulled out of the clamping opening.

A structure having a surface structure capable of controlling friction anisotropy and a sliding device utilizing the structure are provided. [Solution] The structure 1 comprises a surface 2 and a structural substance 6 defined by the surface 2, wherein the surface 2 forms a surface structure 4 including a reference surface 3 and a plurality of surface structure elements 4a, the surface structure elements 4a having a convex structure formed on the reference surface 3 and having an inclined structure 4ap inclined relative to the reference surface 3, the inclined structure 4ap including an inclined rising surface portion 4as and a descending portion 4ad descending from an apex 4at of the inclined rising surface portion to the reference surface 3, the gradient of the inclined rising surface portion 4as being equal to or less than the gradient formed by the apex 4at and the vertical direction from the apex 4at toward the reference surface 3, and the gradient of the descending portion 4ad being greater than the gradient of the inclined rising surface portion 4as.

The utility model discloses a scorpion anti-oxidation packaging device, which relates to the technical field of packaging, and comprises a tank body, a tank cover hermetically matched with an opening of the tank body, and a plurality of partition plates arranged in the tank body and used for dividing an inner cavity of the tank body into a plurality of independent cavities for storing scorpions; the protruding structure is arranged on the inner side of the tank cover, is provided with a filling cavity and is used for storing deoxidizing filler; the communicating assembly is arranged in the inner cavity of the tank body and used for communicating the filling cavity with gas in each independent cavity in the tank body; the blocking assembly is arranged at the opening of the tank body and used for blocking air leaking into the tank body from the tank cover; wherein the opening end of the tank body is provided with a step surface which is in matched contact with the protruding structure, the tank body is provided with an annular groove at the position of the step surface, the annular groove is formed in the circumferential direction of the tank body, and the blocking assembly is arranged in the annular groove. The method has the effect of improving the quality stability of the scorpions.

The embodiment of the utility model provides water drinking equipment. The water drinking equipment comprises a machine body, and an opening is formed in the top of the machine body; the cover body covers the opening, the cover body comprises a plug body part, the plug body part is used for being inserted into the opening and matched with the opening, the orthographic projection of the plug body part on the horizontal plane is in a polygon shape and is provided with a plurality of corners, and the shapes and / or sizes of the corners are different so that the cover body can be limited to cover the opening in the set direction. Compared with the prior art that the cover body and the machine body are matched through an additionally-arranged concave-convex structure, the cover body and the machine body are matched through differentiated corners, the appearance attractiveness of the plug body part can be guaranteed, the attractiveness of the cover body and the machine body can be improved, the product texture can be improved, and the accuracy of the installation position of the cover body can be guaranteed.