105 results about "Upper wing" patented technology

The invention discloses a folding wing structure of an unmanned aerial vehicle, which comprises a rotating shaft embedded in a vehicle body, wherein a lower wing elastic sheet and an upper wing elastic sheet are mounted in an inner cavity of the rotating shaft from bottom to top, a first locking block and a second locking block are respectively arranged at the free ends of the lower wing elastic sheet and the upper wing elastic sheet, the first locking block and the second locking block are respectively matched with a first notch and a second notch which are formed in the rotating shaft, the outer side of the rotating shaft is sequentially sleeved with a lower wing and an upper wing from bottom to top, the upper surface of the lower wing and the lower surface of the upper wing are each provided with a groove, the two grooves are oppositely formed to form a torsional spring groove, a torsional spring is arranged in the torsional spring groove, and the upper inner sides of the lower wingand the upper wing are provided with a first locking groove and a second locking groove correspondingly; and the outer side of the rotating shaft is further sleeved with a roller bearing, a baffle isinstalled at the top of the rotating shaft, and the roller bearing is located between the upper wing and the baffle. The processing cost of the unmanned aerial vehicle is reduced, the folding wing structure is insensitive to the structural size, and the folding wing structure can adapt to a more miniaturized barrel-shooting unmanned aerial vehicle.

The invention relates to the technical field of aircrafts, in particular to a telescopic wing type aircraft with a self-adaptive duct and a control method, and the telescopic wing type aircraft comprises a rack, a lifting force assembly, a power assembly and an adjusting assembly; the lifting force assembly comprises a telescopic wing mounted at the top end of the rack and an empennage mounted at the tail end of the rack; the power assembly comprises self-adaptive duct sets installed on the two sides of the rack, and the self-adaptive duct sets are located on the two sides of the bottom ends of the telescopic wings and used for preventing airflow from disturbing the telescopic wings. When the unmanned aerial vehicle ascends and descends vertically, power airflow can be sprayed out vertically and downwards almost and cannot be blocked or turned back by wings above, thrust is utilized to the maximum degree to overcome gravity, the thrust-weight ratio and the hovering efficiency are improved, and attitude control is more direct and accurate; in the cruising state, the positions of the self-adaptive duct sets prevent airflow from directly impacting the surfaces of the wings, smooth airflow on the surfaces of the wings is prevented from being damaged, vortexes are prevented from being generated, the power efficiency is improved, and thrust loss caused by airflow impact is avoided.

1. Name of the designed product: clip set (butterfly). 2. Use of the designed product: for clipping articles. 3. Design points of the designed product: in shape. 4. Picture or photo best indicating the design points: assembly state diagram. 5. Component 4 is the same as component 2, and component 5 is the same as component 3, and the views of component 4 and component 5 are omitted. 6. Other circumstances needing explanation: component 1 is a butterfly base, component 2 and component 4 are butterfly lower wings, and component 3 and component 5 are upper wings.

The utility model discloses a double-sided puller and a zipper, and relates to the field of zippers. A double-sided pull head comprises a pull head body and a rope used for pulling the pull head body to slide. The puller body comprises an upper wing plate, a lower wing plate and a connecting column, wherein the upper wing plate and the lower wing plate are vertically arranged, and the connecting column is fixed between the upper wing plate and the lower wing plate and located at the front end of the puller body. The upper wing plate is provided with an upper side tunnel which is through in the front-back direction, the lower wing plate is provided with a lower side tunnel which is through in the front-back direction, the front end opening of the upper side tunnel and the front end opening of the lower side tunnel both extend to the front side space of the connecting column, and the upper side tunnel, the lower side tunnel and the front side space of the connecting column form a rope channel; the rope movably penetrates through the rope channel, the head end of the rope can penetrate through the rear port of the upper side tunnel to be exposed, the head end of the rope is provided with an upper blocking part, the tail end of the rope can penetrate through the rear port of the lower side tunnel to be exposed, and the tail end of the rope is provided with a lower blocking part. The problem that the rope is broken due to scraping at least can be solved.

A winglet system is configured to be secured to a wing of an aircraft. The winglet system includes an upper blade, a lower blade, and a cover plate integrally formed with the upper blade and the lower blade. The cover plate covers an opening within a transition joint between the upper blade and the lower blade. The cover plate remains coupled to the upper blade if the lower blade is separated from the winglet system.

The invisible pull head comprises a pull head body, the pull head body comprises a lower wing plate, a side plate and an upper wing plate, a separation column is arranged on the lower wing plate, a pull piece is hinged to the top of the separation column, a Y-shaped channel is formed among the separation column, the lower wing plate, the side plate and the upper wing plate, a mounting hole is formed in the top of the separation column, and the mounting hole is higher than the upper wing plate. A cloth passing space is formed between the zipper pull and the upper side of the upper wing plate when the zipper pull is horizontally placed; the separation column is provided with a front convex part, and the front convex part is internally provided with a bow-shaped accommodating cavity and a bow-shaped elastic sheet; and the mounting hole is close to the front convex part, so that the mounting hole and the upper wing plate are staggered. On one hand, a cloth passing space is formed between the pull piece and the upper wing plate by lifting the mounting position of the pull piece; and on the other hand, the rotating shaft of the pull tab and the upper wing plate are staggered in a mode that the mounting hole deviates towards the front convex part, so that the rotating shaft of the pull tab is prevented from being propped against the cloth belt, and the movement of the invisible pull head is smoother.

The invention relates to the technical field of fully-mechanized top coal caving face conveying equipment, in particular to a middle trough with a replaceable upper wing plate, which comprises a middle trough body, the upper wing plate, a connecting bolt and a nut. In the operation process of a scraper conveyor on the rear portion of a fully-mechanized top coal caving working face, the upper wing plate of the middle trough is seriously abraded, according to the split structure of the upper wing plate and the trough body of the middle trough, the upper wing plate can be quite conveniently disassembled and replaced underground when the upper wing plate is seriously abraded, and the original notch section matching size of the middle trough of the scraper conveyor is recovered; the scraper chain can operate normally, smooth conveying of raw coal is achieved, and normal production of a fully-mechanized top coal caving working face is guaranteed.

A supersonic aircraft is disclosed herein. The supersonic aircraft comprises one or more fuselages, one or more wings, at least one wing-mounted engine, at least one inlet mounted on the upper surface of or above the wing, an upper wing surface propulsion system fairing, and a lower wing surface propulsion system fairing or lower wing surface modification to account for the presence of the engine.

The bucket rod comprises a bucket rod body, a front support is arranged at the front end of the bucket rod body, a rear support is arranged at the rear end of the bucket rod body, and a connecting structure is arranged in the bucket rod body. The bucket rod body comprises an upper wing plate, a lower wing plate, a left web plate and a right web plate, the connecting structure comprises a center body and a plurality of peripheral rib plates, the center body is fixedly connected among the peripheral rib plates, the left end faces of the center body and the peripheral rib plates are fixedly connected with the left web plate, and the right end faces of the peripheral rib plates are fixedly connected with the right web plate. The right end face of the center body and the right end face of the peripheral rib plates are fixedly connected with the right web, and the ends, away from the center body, of the peripheral rib plates are fixedly connected with the upper wing plate, the lower wing plate and the rear support correspondingly. The bucket rod is reasonable in structural design, the overall rigidity and strength level of the bucket rod are obviously improved, and the force flow transmission path of the upper lug plate, the rear support and the lower lug plate hinged hole of the bucket rod is greatly optimized.

The utility model relates to the technical field of automobile parts, disclose a quick installation structure of automobile exhaust system heat shield, including upper cover body and lower cover body, the outside of upper cover body is provided with installation mechanism, the outside of upper cover body is provided with heat abstractor, the outside of upper cover body is provided with reinforcing mechanism, the outside of upper cover body is provided with connecting mechanism, the installation mechanism includes upper wing board, the outer wall fixed connection in the left side of upper cover body of upper wing board, the left side fixed connection of lower cover body has lower wing board, the bottom fixed connection of upper wing board has two fixed blocks, the front and back of two fixed blocks all are fixedly connected with elastic gasket. In the utility model, the heat shield is installed through the fixed block of upper wing board and is engaged with lower wing board, is inserted into the plug pin fixed from the embedded entry to the through hole inside, the plug pin tail connects the limiting ring and the supplementary pin, and the plug pin is prevented from popping out by abutting against, has good steady attribute, and the convenient installation and replacement are facilitated.

The utility model provides an orthodontic bracket which comprises a bottom plate, a fixing block is arranged on the bottom plate, the fixing block comprises an upper wing and a lower wing, a sliding groove is formed in the top surface of the upper wing in a penetrating mode, a lock cover is connected in the sliding groove in a sliding mode, a first groove is formed in the sliding groove, and the first groove is formed in the vertical inner wall of the side, close to the bottom plate, in the sliding groove. A through hole is formed in the position, corresponding to the first groove, of the lock cover, a shaft wire is arranged in the through hole, one end of the shaft wire is located in the first groove, a limiting protruding block is arranged on the vertical inner wall of one side of the first groove and divides the first groove into two symmetrical containing grooves, and the shaft wire is made of deformable materials. The first groove with the limiting bump in the sliding chute is matched with the deformable shaft wire, so that the shaft wire is adjusted between the two placing grooves and is blocked and fixed by the limiting bump when the lock cover is opened and closed, stress concentration of a traditional sliding rail is avoided, the risk that the lock cover falls off is reduced, and stable transmission and effect of correction force are guaranteed.

The application discloses a manufacturing method and a column head of a multi-ledge steel column, and the manufacturing method comprises the following steps: S1, manufacturing a round pipe column; S2, manufacturing a top cover unit and a pipe side unit; S3, sequentially assembling and welding a plurality of pipe side units with the round pipe column, the plurality of pipe side units are distributed at intervals around the round pipe column and second inner partition plates and second process partition plates are arranged between the pipe side units; S4, respectively assembling and welding the top cover unit with the round pipe column and the pipe side unit; S5, welding and arranging third inner partition plates and third process partition plates in the round pipe column; S6, arranging second side plates between every two adjacent pipe side units to form corresponding prisms by combined welding; S7, manufacturing a ledge unit, the upper wing plate of the ledge unit is not welded first, and the remaining components are welded; and S8, sequentially assembling and welding a plurality of ledge units with the prisms, the box-shaped body of the ledge unit is welded first, and then the upper wing plate is assembled and welded. By decomposing the component into a multi-unit combined structure form, the component assembly process design is optimized, the assembly and welding of the ledge unit are facilitated, and the component is convenient to use.

The utility model relates to the field of cargo compartment design, and discloses a cargo compartment structure which comprises a bottom plate, the bottom plate is rotationally connected with a breast board assembly, a fixed beam is arranged at the bottom end of the bottom plate, an edge beam is arranged on the edge of the bottom plate, one end, away from a web plate, of an upper wing plate of the edge beam downwards forms a first flanged plate, and the end of the fixed beam is embedded into a groove of the edge beam and fixedly connected with the first flanged plate. The top end of the fixing beam is flush with the edge beam, the outer side of the bottom end of the breast board assembly is arranged in a downward protruding mode, an L-shaped groove allowing the end of the bottom plate to be embedded is formed between the outer side of the bottom end of the breast board assembly and the inner side of the bottom end of the breast board assembly, and when the breast board assembly rotates to be vertical, the edge of the bottom plate is embedded into the L-shaped groove in the bottom end of the breast board assembly. Rainwater is prevented from entering the cargo compartment from the gap between the breast board assembly and the bottom board, gaps exist between the fixing beams and the edge beams through the first flanged boards, flowing of electrophoresis liquid is facilitated, the fixing beams and the edge beams can be fully coated, and the bottom board structure has the effects of enhancing the corrosion resistance of the bottom board structure and preventing cargoes in the cargo compartment from being wetted.

The present invention is a zipper (1) having left and right zipper tapes (10), at least one slider (20), and a stopper (30) for the slider (20) to abut against, the stopper (30) being fixed across the left and right zipper tapes (11) and having a shape in which a portion of the stopper (30) can be inserted between the upper wing plate (22) and the lower wing plate (23) of the slider (20), the interval in the tape width direction between the left and right zipper teeth (13) in a state in which the left and right zipper tapes (10) are separated is defined as a tooth interval (A), the maximum value of the dimension in the tape width direction of the connecting column (24) of the slider (20) is defined as a column maximum width (B), and the tooth interval (A) is a size of 100% or more and 150% or less of the column maximum width (B). Thus, when the slider (20) is caused to slide toward the stopper (30), it is difficult for the zipper teeth (13) to fall over in the vicinity of the stopper (30), and it is possible to suppress the zipper teeth (13) from being caught in the slider (20).

The present application relates to the technical field of aircraft design, and particularly relates to a wide-speed-range aircraft based on a variable high-pressure capture wing shape and a control method thereof, which comprises a fuselage, an upper wing surface, a lower wing surface, a foldable canard, a variable high-pressure capture wing and a control system. The variable high-pressure capture wing is arranged above the fuselage and the upper wing surface, and is used for switching between a subsonic forward-swept configuration and a supersonic backward-swept configuration according to a flight speed range; the foldable canard is arranged at a leading edge of the wing surface, and is used for unfolding in a subsonic stage and folding to be attached to the lower wing surface in a supersonic stage; and the control system determines a current stage according to flight state parameters, and cooperatively drives the high-pressure capture wing and the canard to perform a configuration switching action. The present application realizes adaptive matching of an aerodynamic shape and a flight speed range through variable design.

An articulated machine 100 has a body portion 105 and a wing portion 110 comprising an active member and mounted on body portion 105. Wing portion 110 is moveable between a first (for example, lowered

The present invention provides a zipper pull. The zipper pull (1) of the present invention has a zipper pull body (10) having an upper wing plate (20) and a lower wing plate (30). A pair of groove portions (50, 60) are provided on the inner surface of the upper wing plate (20) and / or the lower wing plate (30). In a cross-sectional view of the zipper pull body (10), with the outermost position in the zipper pull width direction of the outer periphery of the connecting post (40) defined as the outermost position (41), the inner groove side edge portion (52a) of each groove portion (50, 60) is positioned inside the zipper pull width direction than the outermost position (41), and the outer groove side edge portion (52b) of each groove portion (50, 60) is positioned outside the zipper pull width direction than the outermost position (41). Therefore, even with repeated sliding operations, it is not easy to cause scraping of the zipper teeth caused by the inner surface of the zipper pull body (10).

1. Name of this design: Upper wing plate of pull head base. 2. Application of this design: The zipper pull base is used for zipper pull accessories; the upper wing plate of the zipper pull base is used for zipper pull accessories. 3. The key design features of this product are the combination of shape and color. 4. The image or photograph that best illustrates the design's key points: a 3D model. 5. The design for which protection is sought includes color. 6. Other situations requiring explanation: Other explanation: The parts covered in red are protected parts, and the parts not covered are unprotected parts.

A kind of steel bridge distortion fatigue carbon fiber cloth and multi-limb angle steel composite reinforcing structure and process, vertical steel plate beam web is arranged between upper wing plate and lower wing plate, vertical stiffening rib is arranged between steel plate beam web and wing plate, horizontal node plate is vertically arranged in the height direction of steel plate beam web, vertical stiffening rib vertically passes through horizontal node plate, and horizontal node plate web gap area and vertical stiffening rib web gap area are reinforced using carbon fiber reinforced resin base and multi-limb angle steel composite structure;When reinforcing using the reinforcing process, before the strength of composite structure glue layer is not consolidated to form, auxiliary device needs to be fixed, after removing auxiliary reinforcing device, carbon fiber cloth is pasted on the surface of angle steel to form composite reinforcing structure layer.The reinforcing structure is suitable for 50-100mm long distortion fatigue crack reinforcement, can effectively improve the stress performance of web gap, improve the ability of inhibiting detail distortion fatigue crack initiation and expansion, has the advantages of convenient construction, low cost and excellent performance.

This application relates to the field of vehicle technology. The present invention provides a riding vehicle, comprising: a power system including a power source providing power; a walking system including wheels that can be driven by the power system; a frame supporting the power system; a housing assembly housing the frame and the power system; and a control system for controlling the movement of the riding vehicle. The riding vehicle further comprises: two winglets respectively connected to both sides of the vehicle body, each winglet including an upper wing and a lower wing. The upper wing is connected to both sides of the vehicle body and extends outward relative to the vehicle body, while the lower wing is connected to both the upper wing and the vehicle body. The upper wing includes a windward portion, the upper end of which has a first windward surface, at least partially being a curved surface concave inward towards the windward portion. This application provides a riding vehicle that effectively prevents the front wheel from lifting off during high-speed travel by providing winglets, and the winglets do not excessively increase wind resistance.

The present application relates to a kind of box beam / column's assembly welding method and assembly welding structure, the method is: after main body workpiece is assembled together, concentrate on the welding of workpiece, box shape assembly: lower wing plate is fixed as bottom plate;Install baffle on lower wing plate;Assemble left web plate and right web plate;Assemble upper wing plate;Box shape welding: welding machine enters from the welding hole of upper wing plate, and the welding of each baffle and left, right web plate is carried out electric slag welding;Component is turned over 90 degrees, and welding machine enters from the welding opening of web plate side, and the welding of each baffle and upper, lower wing plate is carried out electric slag welding;Finally, the welding of four longitudinal welds of box shape outside;The structure is: baffle all is electric slag welding weld around;Upper wing plate is provided with welding hole corresponding to first weld, and first weld is continued to the surface of upper wing plate welding hole from lower wing plate;Left web plate / right web plate two sides are provided with welding opening corresponding to second weld, and second weld is connected with the longitudinal weld of left web plate / right web plate two sides.

The present disclosure relates to assembly line fabrication and assembly of aircraft wings. Systems and methods for assembling a wing are provided. The method includes suspending an upper wing panel of an aircraft below a shuttle, translating a rib into position, and placing the rib in contact with the upper wing panel, and then securing the rib to the upper wing panel while the upper wing panel is suspended. Some methods include installing a rib and spar to the upper wing panel while the upper wing panel is suspended, and joining a lower wing panel to the rib and spar. Some methods involve joining a rib to a spar (e.g., in whole or in part) to create a support structure, and then securing the support structure to the upper wing panel. The system includes a shuttle to suspend the upper wing panel, and a cart including a support to hold the rib, a chassis to translate the rib into position below the upper wing panel, and a lifting device to lift the rib into contact with the upper wing panel.

The utility model relates to a construction structure for reinforcing a landslide by cast-in-place high-bending-resistance anti-slide piles, which structurally comprises a plurality of unit I-shaped anti-slide piles, each unit consists of an upper wing plate pile, a web pile and a lower wing plate pile, and the web pile is vertically connected with the upper wing plate pile and the lower wing plate pile to form a horizontal support. A plurality of unit I-shaped anti-slide piles can be continuously arranged to form an underground diaphragm wall, or the intervals are adjusted according to needs to form discrete I-shaped anti-slide piles. The bending rigidity of the I-shaped section is 3.69 times and 4.15 times that of a square pile and a round pile respectively, and landslide thrust can be effectively resisted. Through modular design and I-shaped section optimization, the problems that a traditional anti-slide pile is insufficient in flexural rigidity and poor in geological adaptability are solved, and the anti-slide pile is suitable for narrow sites and complex geological conditions and has both structural stability and construction flexibility.

This invention relates to the field of aerodynamic component technology, and in particular to a wing spoiler device for a ground effect vehicle (GEV). The wing spoiler device for a GEV includes: a base, a movable flap, the front end of which is hinged to the front of the base, and the rear end of which is fixed to the rear of the base via an adjusting fastener passing through a pre-set first adjusting and fixing hole. The spoiler device is mounted above the front wing of the GEV via the base, so that when the incoming airflow passes over the upper wing surface, it obstructs the downwash airflow converging at the trailing edge of the wing, generating vortices inside the spoiler device to reduce the lift of the upper wing surface and increase the ground effect ratio of the lower wing surface, thereby suppressing the aerodynamic center of gravity shift of the GEV. The advantages of this invention are its simple structure, low manufacturing cost, and the elimination of the need for active control components such as servos or other transmission electronic devices. It also features a robust structure, better adaptability to harsh water environments, reduced safety hazards, and extended service life of the aircraft.

The application belongs to the technical field of aircraft design, and particularly relates to a high-lift-coefficient layout aircraft and a use method thereof. The aircraft comprises a fuselage, a hump arranged on an upper middle part of the fuselage, a lower wing connected to the hump, an upper wing located above the lower wing and detachably connected to the lower wing, the upper wing being connected to the lower wing through an actuator and a four-bar linkage mechanism, the separation or adhesion of the upper wing relative to the lower wing being controlled by the actuator, a trailing edge flap and aileron arranged on a trailing edge of the lower wing, a V-tail stabilizer connected to a rear part of the fuselage and a V-tail control surface connected to a tail part of the V-tail stabilizer, and an engine connected to the fuselage. The application can greatly increase wing area and effective angle of attack, and significantly improve take-off and landing lift.

The utility model belongs to the technical field of steel structures, and particularly relates to a bearing type steel structure beam column and accessories. Comprising a group of vertically-welded steel columns and novel load-increasing steel beams, each steel column is composed of a left flange plate, a web plate, a right flange plate and a stiffened plate, the two ends of the web plate are vertically connected to the middle of the left flange plate and the middle of the right flange plate, and the two sides of the left flange plate and the two sides of the right flange plate are each provided with a bend inwards. The stiffened plate is perpendicular to the two bends at the two parallel ends of the web plate; the steel beam is composed of an upper flange plate, a web and a lower flange plate, two sides of the upper flange plate are provided with bends inwards and are connected with the steel columns at the two ends through vertical bolts, the whole structure is not changed from a traditional style, but a main component is made of the bends and pull rods on the lower portion of the steel beam. According to the bearing-increasing type steel structure beam column and the accessory, the bearing capacity of the H-shaped steel is increased through the novel steel structure, design standard loads are achieved through fewer steel materials, the structure of a building can be more stable, and the cost is lower.

The invention discloses an H-shaped steel full-automatic production method and system based on assembly line cooperative control, and relates to the technical field of automatic equipment. According to the core technical scheme, synchronous feeding is conducted through three independent roller lines, and a lower wing plate, a web plate and an upper wing plate are centered; the web plate and the lower wing plate as well as the T-shaped steel and the upper wing plate are automatically assembled and subjected to spot welding forming on the first assembly station and the second assembly station in sequence through an electromagnetic turnover mechanism; and preheating, bilateral synchronous submerged-arc welding and deformation correction are sequentially carried out on the T-shaped steel and the H-shaped steel at the assembling, welding and correcting integrated station. The method solves the problems that in the prior art, the automation degree is low, the collaboration of all production units is poor, the product quality is unstable, and the flexibility of a production line is insufficient. According to the invention, the full-process automation and intelligent control are realized, the production efficiency and the product consistency are obviously improved, and the flexible production capacity is good.

This invention discloses a method, device, and electronic device for establishing a point cloud coordinate system for a vehicle, belonging to the field of automotive technology. The method includes: selecting four locations at the front end of the upper wing of the vehicle frame, and randomly selecting three of them to construct a Z-X reference plane; constructing a reference axis: obtaining reference circles C1 and C2 representing the circumferential positions of the wheel hubs on both sides of the drive axle through planar constraint projection and double-circle fitting technology; generating a feature line L1 by connecting the geometric center of reference circles C1 and C2; generating a symmetry plane in the middle of the straight section of the left and right longitudinal beams of the vehicle frame; constructing a vertical plane perpendicular to the Z-X reference plane through the reference axis; the symmetry plane, the Z-X reference plane, and the vertical plane intersect at a point, i.e., a reference point; calculating the origin of the final coordinate system based on the front axle wheel hub data; establishing an initial coordinate system, and then translating the initial coordinate system until the reference point and the origin of the final coordinate system coincide, thus obtaining the final coordinate system. This application significantly improves accuracy: the Y-axis error is reduced by more than 90%.

The utility model discloses a replaceable zipper which comprises a lower wing plate, the upper surface of the lower wing plate is fixedly connected with a connecting base, the two sides of the upper portion of the connecting base are fixedly connected with connecting blocks, the inner surfaces of the connecting blocks are fixedly connected with a fixing shaft, the two ends of the fixing shaft are rotationally connected with upper wing plates, and the upper wing plates are fixedly connected with the lower wing plate. A zipper strip is connected between the upper wing plate and the lower wing plate in a clamped mode, a connecting piece is rotationally connected to the upper surface of the connecting base, a second clamping block is driven to move through control over an adjusting block to achieve fixing and releasing of the upper wing plate, the upper wing plate of the zipper head can be turned over conveniently, and therefore buckling of zipper teeth is canceled, and the zipper head is convenient to use. The zipper head can be conveniently taken down for replacement, the replacement efficiency is improved, meanwhile, clothes are prevented from being damaged, through the arrangement of the push rod, the first spring and the first clamping block, the connecting piece can be conveniently fixed and released, the connecting piece can be conveniently turned over and opened, the pulling piece can be conveniently replaced, and the maintenance cost of the zipper head is reduced.