112results about How to "Not easy to loosen and fall off" patented technology

The invention relates to a swinging-block type child seat safety buckle for an automobile, mainly comprising a buckle pulling main body and inserting pieces matched with the buckle pulling main body and can be inserted in and pulled out from the buckle pulling main body, wherein the buckle pulling main body comprises an upper cover, a lower cover, a button and a buckle pulling core body; the buckle pulling core body comprises an upper cover plate, a lower cover plate, a locking piece arranged on the lower cover plate, a left swinging block, a right swinging block, a left torsion spring, a right torsion spring and a top spring; and the locking piece pushes against or loosens the left swinging block and the right swinging block so that the left swinging block and the right swinging block get in a pushing or separated state with the button. In the invention, the locking piece pushes against middle lugs corresponding to the left swinging block and the right swinging block so that inserting hooks of the inserting pieces can be buckled with upper concave openings corresponding to the left swinging block and the right swinging block so as to realize locking of the safety buckle; or the locking piece pushes against lower lugs corresponding to the left swinging block and the right swinging block so that the concave openings corresponding to the left swinging block and the right swinging block release the inserting hooks of the inserting pieces so as to realize the release of the safety buckle. The swinging-block type child seat safety buckle has simple and compact structure and few linking pieces and is convenient to manufacture and use;, the matching structure of all components is stable and the locking is sensitive and hardly loosens or falls off, therefore the use safety performance is high.

The invention discloses a trim strip for a shelf, a shelf with the trim strip and a refrigerator with the shelf. The trim strip for the shelf comprises a body. An installation groove with an opening facing left and stretching forwards and backwards is formed in the body. A first anti-skidding protrusion and a flexible anti-skidding strip are formed on the lower surface of the upper side wall of the installation groove. The fixed end of the flexible anti-skidding strip is located at the left side of the first anti-skidding protrusion and the free end of the flexible anti-skidding strip is located below the first anti-skidding protrusion. The trim strip for the shelf is firm in match, not prone to loosening and falling, simple in structure and reliable in assembly.

The invention provides a connection structure of a connection end of a component and a connection terminal used in instruments and meters, discloses the connection structure of the connection end of the component and the connection terminal which is especially suitable for the field of electric energy meters, and aims at providing the connection structure of the connection end of the component and the connection terminal which is simple in structure, low in resistance in a contact position of the connection end of the component and the connection terminal, large in axial torsion of the connection terminal and low in self-power-consumption. The connection structure of the connection end of the component and the connection terminal comprises the connection terminal and a sampling device, wherein the connection terminal is a metal connection cylinder. Two ends of the metal connection cylinder are respectively provided with opposite holes, and the opposite holes are not communicated with each other. One end of the connection terminal is provided with a connection hole used for input and output of meter external power, and the other end of the connection terminal is connected with an input and output end binding post of the component, and a compression joint structure is formed by the other end of the connection terminal and the input and output end binding post of the component. The connection structure of the connection end of the component and the connection terminal has the advantages of being simple in structure, and convenient to produce and assemble. Meanwhile, the connection structure of the connection end of the component and the connection terminal can not loose or fall off easily and can improve usability of the component and the like.

The invention relates to a high-power power electronic capacitor for elastic connection among core sets and copper bars. The high-power power electronic capacitor comprises a cover plate assembly, an outer shell and the core sets. The core sets are fixed in the outer shell, leading-out copper strips are arranged on the two metal sprayed faces of each core set respectively, and bent leading-out electrodes are arranged at the upper ends of the leading-out copper strips and used for being electrically connected with leading-out terminals of the cover plate assembly through welding. Elastic conducting plates are arranged on the leading-out copper strips and extend to all capacitor core metal sprayed faces of the core sets, and the tail end of each elastic conducting plate is electrically connected with the corresponding capacitor core metal sprayed face through the welding. The core sets are connected with the leading-out copper strips in an elastic mode. The force, adhering to the elastic conducting plates, of welding points is strengthened. The situation that the leading-out copper strips have sufficient properties of current passing can be guaranteed, and in addition, the situation that the displacement of the core sets causes the welding points to be strained can be eliminated, so that the welding points are not prone to loosening and disengaging.

The invention discloses an aluminum oxide ceramic nut and a manufacturing process thereof. The aluminum oxide ceramic nut mainly comprises the following components in percentage by weight: 90-95 percent of aluminum oxide, 1-5 percent of talc powder, 1-5 percent of Suzhou soil and 0.5-1 percent of silicon dioxide. The aluminum oxide is ground and crushed to prepare paste, and the paste is moulded by hot pressure casting, and is fired at a high temperature of 1600 DEG C. The aluminum oxide ceramics nut is high in strength, corrosion-resistant, convergent-divergent which is the same as that of a corundum exposure head, and difficult to loosen and drop during operation.

The invention discloses a spliced structure of a stone floor and a carpet. The stone floor comprises a bonding layer formed on a cement mortar leveling layer, and a stone board on the bonding layer; the carpet close to the stone floor end comprises a wooden keel fixed on the cement mortar leveling layer, a barb board fixed on the wooden keel and a carpet surface layer on the barb board; the joint of the stone floor and the carpet is provided with a connecting piece; the connecting piece comprises a stone floor protection wall and a carpet protection wall; a buckling groove is formed between the floor protection wall and the carpet wall; the stone floor protection wall clings to the bonding layer of the stone floor and the end face, which faces the carpet direction, of the stone board; the carpet protection wall clings to the end faces, which face the stone floor direction, of the wooden keel and the barb board; and the carpet surface layer extends into the buckling groove. The spliced structure has the characteristics of smooth joint, natural transition, installation firmness and the like between the stone floor and the carpet, and the attractiveness of the splicing position between the stone floor and the carpet is ensured; and corners of the stone floor or the carpet are prevented from being damaged, and the decoration quality is ensured.

The invention discloses a casting method of a metal composite lining plate, and relates to the technical field of casting. The method comprises the following steps: a first molten metal is injected into a casting mold which is formed by closing a lower mold and an upper mold of a first metal layer, and the upper mold of the first metal layer is removed under the high-temperature state after the first metal layer is solidified; an upper mold of a second metal layer and the lower mold are subjected to mold closing, a mold is vacuumed, and then a second molten metal is poured into a mold cavity; after pouring is completed, the ultrasonic vibration is applied for 23-29 seconds, the second molten metal is solidified and cooled, and a metallurgical bonding state is achieved between the second molten metal and the first molten metal. According to the casting method of the metal composite lining plate, the problem that a clear binding interface cannot be formed due to the fact that a mixing phenomenon is prone to occur during casting the existing metal composite lining plate.

The invention discloses a fast-plug tail cable testing connector, and the connector comprises a main housing, a front medium, a rear medium, an internal conductor, a wire clamp, and a locking housing.The front side of the front medium abuts against a first step of an inner hole of the main housing, and the rear medium is fixedly disposed at the central part of the internal conductor in a sleevingmanner. A front plugging connection head of the internal conductor stretches into the inner hole of the front medium, and the front side of the rear medium abuts against the rear side of the front medium. The front end face of the wire clamp abuts against a second step of the inner hole of the main housing, and compresses the rear side of the rear medium. The central part of the inner hole of thewire clamp extends out of an annular positioning platform. When a cable is inserted, an end face of the cable shielding layer abuts against the annular positioning platform, and the annular positioning platform falls into a cable air medium ring. The front end of the locking housing is in screw fit with the rear end of the inner hole of the main housing. The connector is simple in structure, andis low in cost. During testing, only the end of the tail cable needs to be inserted into the connector; after testing, the end of the tail cable is plugged out, thereby achieving the quick plugging connection and disconnection of the connector and the cable, enabling the operation to be convenient, and greatly improving the cable testing efficiency.

The invention discloses a DC motor, which comprises a shell body, wherein a front end cover is fixedly installed on the front surface of the shell body, an output shaft is rotatably connected to the middle of the front surface of the shell body in a manner of penetrating through the front end cover, an installation base is welded to the lower surface of the shell body, a rear cover is fixedly installed on the rear surface of the shell body, a stator is fixedly installed on the inner wall of the shell body, a rotor is rotatably installed in the middle of the interior of the stator, an armatureis arranged at one end of the interior of the shell body, and a magnet yoke assembly is arranged at the position, close to the armature, of one end of the interior of the shell body. By arranging a heat dissipation opening sealing device, the problems that a motor is short-circuited and burnt due to the fact that water easily enters a direct-current motor working in a humid environment or outdoorsand is affected with damp, and meanwhile in a factory environment, much dust exists in air and can enter the motor through a heat dissipation net to cause poor heat dissipation are solved, and finally, the ventilation and heat dissipation effects are achieved while the problem of motor burnout is solved.

The invention discloses a forming die for a piston valve plate. The forming die comprises an upper sand box and a lower sand box, wherein each of the upper sand box and the lower box is of a box structure with hollow inside and open upper and lower bottom surfaces, a plurality of bent partition plates are arranged at the upper end of the inner cavity of the upper sand box and the lower end of theinner cavity of the lower sand box respectively, and a plurality of first cooling channels penetrating through two ends of the partition plates are formed in each partition plate; first extension blocks extending inwards are arranged on the inner wall of the upper end of the lower sand box, a base is fixed at the bottom of the lower sand box through bolts, a bottom plate is arranged above the base, and a plurality of compression springs are arranged between the bottom plate and the base; an upper cavity with semicircular section and arc-shaped side wall is formed in the upper sand box; a lowermold cavity matched with the upper mold cavity is formed in the lower sand box. The forming die can effectively prevent molding sand in the sand boxes from loosening and falling off, stability of thesand boxes is improved, and accordingly, casting quality of products is greatly improved; besides, the use amount of the molding sand is reduced, the production cost is reduced, and the cooling effect is good.

The invention discloses a spraying device with a quick drying function for production of steel sheets of windscreen wipers, and relates to the technical field of production of automobile parts. The spraying device specifically comprises a base, a screw rod chuck mechanism, a wedge clamping mechanism, a spraying mechanism and a quick drying mechanism, wherein a supporting column is arranged at oneend of the top end of the base; and the screw rod chuck mechanism is arranged at the bottom end of a lifting ring. According to the spraying device with the quick drying function for production of thesteel sheets of the windscreen wipers, the quick drying mechanism is arranged, a circulating mechanism is arranged, so that uniform distribution of the temperature in a cavity of a rack is guaranteed; a sliding groove which is shaped like a Chinese character 'jing (well)' is formed in the surface of a drying layer, so that a magnetic base can freely move on the surface of the sliding groove conveniently, and the adaptability to to-be-dried materials of different types and specifications is high; the magnetic base guarantees effective adsorption, and meanwhile, the contact between the magneticbase and the to-be-processed materials is reduced, so that the drying effect is guaranteed; and the drying layer and a heating layer can run at different rates due to the arrangement of a differential mechanism, so that the to-be-dried materials are uniformly heated, the drying rates of different parts are consistent, and the applicability is higher.

The invention discloses a clamping device with a ratchet device for a ground wire. The clamping device comprises a chuck, a propelling post, a clamping piece, a connection frame, an insulating rod and a ratchet fastening device, wherein the chuck comprises an upper bump, a lower bump and a connection block; the upper bump and the lower bump are arranged in parallel and are fixed at two ends of the connection block separately to form a structure with a groove; the propelling post passes through the lower bump and is in threaded connection with the lower bump; the clamping piece is fixed at one end, entering the inside of the groove, of the propelling post; a fixture block is arranged at one end, outside the chuck, of the propelling post and is a polygon; the ratchet fastening device is hinged with the connection frame; the connection frame is fixedly connected with the insulating rod; the ratchet fastening device comprises a fixture block mating hole; and the fixture block mating hole is in fit connection with the fixture block. By adopting the ratchet device, the target that the propelling post can only rotate in the same hour hand direction and cannot rotate in the other hour hand direction in the swing process of the insulating rod can be achieved, so that the single tightening or disassembling process can be continuously achieved through only one-step installation.

The invention belongs to the technical field of new energy automobiles, and particularly relates to a new energy automobile charging gun. The new energy automobile charging gun comprises a protectiveseat, two positioning rails are inserted on the protective seat in a penetrating mode in the left-right direction, and first racks are fixedly connected to the opposite side walls of the two positioning rails. One end of a boosting mechanism is fixedly connected with the end side wall, away from a fixed mechanism, of the protective seat, and a limiting mechanism used for limiting the two positioning rails is arranged in the protective seat. A charging plug is fixedly connected to the end side wall, close to the fixed mechanism, of the protective seat, a power line is fixedly connected to the lower end of the protective seat, and the power line is electrically connected with the charging plug. The new energy automobile charging gun has the advantages that the new energy automobile charginggun has better stability when being connected with an automobile connector, so that the phenomenon of loosing or falling of the charging plug is not prone to appearing, meanwhile, insertion and extraction postures of a user can be standardized and instruction can be provided for the user to protect a charging connector, the service life of the charging connector is prolonged, and using costs of the charging connector are reduced indirectly.

The invention relates to a stressed template component used for a floor system, and the component is composed of a template (1) and is characterized in that the invention also comprises trusses (2) which are parallel and arranged at intervals, and the trusses (2) are arranged on the template (1) and are connected with the template (1) into a whole; the trusses (2) are provided with a top boom (3), a lower boom (4) and a web member (5); wherein, the web member (5) is connected with the top boom (3) and the lower boom (4); the lower boom (4) of the trusses (2) is of an integral elongated template (1); the trusses (2) are of a rodless lower boom (4). The invention is applicable to cast-in-situ reinforced concrete or a hollow floor system, a roof system, walls and a foundation slab of the prestressed reinforced concrete as well as a vierendeel bridge girder, and is particularly suitable for a hollow flat slab.

The invention relates to the field of production machinery of ferrous metallurgy industry, and particularly discloses a rotary scraper and a manufacturing method thereof. The rotary scraper comprises a tool bar and a tool bit connected through a bolt. The rotary scraper is characterized by also comprising a jacket which is sleeved outside the tool bar and the tool bit. The method comprises the following steps of: manufacturing the tool bar; fixing the tool bit on the tool bar by using the bolt, and coating adhesive between the tool bit and the tool bar; sheathing the jacket outside the tool bit and the tool bar; drilling a hole on the bolt from the jacket at the part of deepening the bolt to the tool bar; and jacking a jackscrew into the hole, and vertically fixing the jackscrew on the bolt. According to the technical scheme provided by the invention, the service life of the scraper is prolonged, the integral toughness and the firmness of the scraper are enhanced, and the production efficiency is improved.

The invention relates to an electrical connection column which is formed by integrating an insulation shell, an upper embedded body and a lower embedded body in a hot-casting manner. The upper embedded body is embedded in the upper part of the insulation shell in a reverse screw structure, and a part of appearance of a screw cap of the upper embedded body is of a noncircular structure. The lower embedded body is embedded in the lower part of the insulation shell in a nut structure, and the appearance of a nut of the lower embedded body is of a noncircular structure. A bolt part of the upper embedded body is of an external thread structure, and the external thread part is embedded in the upper part of the insulation shell. The upper part and the lower part of the insulation shell are respectively embedded with the upper embedded body and the lower embedded body in a hot-casting manner, and parts are respectively locked and connected by the upper embedded body and the lower embedded body, thus the electrical connection column disclosed by the invention has a simple and compact structure, small weight, high corrosion resistance, high strength and high plasticity, is firmly connected with the parts, and can meet the requirements on the special performance of aero-products.

The invention discloses an efficient and precise machining method for a plastic mold hanging ring threaded hole and belongs to technical field of threaded hole machining technologies. The technological process in the method comprises the sequential steps that a workpiece material steel plate is sawn; rough milling is performed on the six surfaces of the material steel plate; the material steel plate is pressed; the center of a workpiece is determined; the center of a threaded hole of the workpiece is determined; a blind hole is drilled; a threaded bottom hole is drilled; a T-type hole is drilled; orifice chamfering is performed; internal threads are machined; shutdown is performed so that the threaded hole can be checked; the workpiece is taken down. For the threaded hole obtained through machining based on the method, the perpendicularity of the hanging ring threaded hole is high, and it can be guaranteed that the screw can be screwed to the bottom of a tooth hole; the machining method which is performed from bottom to top is adopted when the internal threads are machined, so that scrap iron will not fly around randomly, and safety is higher; meanwhile, the machined threads are thicker, high in tensile strength and high in safety, and besides the smoothness of the inner wall of the hanging ring threaded hole is higher. In addition, the efficient and precise machining method has the advantages that production is quicker, and quality is more stable.

The invention discloses a high strength steel bar connecting structure capable of achieving rotatable connection, and an operating method. The connecting structure comprises a steel bar A and a steelbar B, and threads are formed in the ends of the steel bar A and the steel bar B through machining; the end of the steel bar A is provided with a connecting piece A in a sleeving mode, and the end ofthe steel bar B is provided with a connecting piece B in the sleeving mode; the connecting piece A is hinged to the connecting piece B, and the exterior of the connecting piece A is provided with a locking cylinder A in the sleeving mode; and the exterior of the connecting piece B is provided with a locking cylinder B in the sleeving mode. The connecting structure has the advantages of rational design, the simple structure, rotatability and higher safety, and is not prone to loose and fall off.

The invention relates to the field of electric connectors, in particular to a method for preventing an electric connector of a manufacturing process from falling off, which comprises the following steps of: S1, providing a magnetic type electric connector of the manufacturing process, simultaneously pressing two groups of pressing keys, and aligning a male plug with a female plug; S2, during insertion, inserting the male plug into the slot of the female plug, loosening the pressing keys, and during pull-out, pressing the two sets of pressing keys at the same time, and pulling the male plug outof the slot of the female plug; wherein magnetic conductive metal grooves are formed in the left side and the right side of the magnetic type electric connector male plug, an inserting groove is formed in the upper side of the female plug, an annular groove is formed in the inner side wall of the middle of the inserting groove, protruding blocks are arranged on the left side and the right side ofthe upper portion of the female plug, sliding openings communicated with the annular groove are formed in the middles of the protruding blocks, and guiding sliding blocks are slidably connected intothe sliding openings. According to the method for preventing the electric connector of the manufacturing process from falling off, the problem that in the prior art, electric connection is prone to being pulled or dragged, loosening and falling off are caused, and accordingly the electric connector cannot work normally can be effectively solved.

The invention relates to the technical field of oil and gas well through-tubing perforation operation, in particular to a chain-type body-free perforator. The chain-type body-free perforator includesat least one bullet holder, wherein perforating bullets are installed on the bullet holders, the perforating bullets comprise shell bodies and shell covers, the shell bodies are connected with the shell covers to form bullet shells with sealed inner cavities, the inner cavities of the bullet shells are filled with explosives, and the explosives are compacted through shaped charge liners installedin the inner cavities of the bullet shells. The chain-type body-free perforator has the beneficial effects that the structures of the bullet shells are simple, disassembly and assembly are convenient,end face sealing is carried out by the shell covers, connection and sealing of the shell bodies and the shell covers are realized through extrusion deformation force between the shell bodies and theshell covers, and performance is reliable; the independent bullet holders serve as carriers of the perforating bullets, the number and the phase position of the perforating bullets are flexibly set conveniently according to needs, all the bullet holders are arranged independently and are not prone to being clamped in casing pipes, moreover, the bullet holders can be broken into fine particles completely after perforation of the perforating bullets, after perforation is finished, the bullet holders do not need to be taken out again, occurrence of the well jamming accident is avoided, and safetyperformance is improved.

The invention relates to an installation structure body for a main reducer of a roller mill and an application method thereof. The structure body comprises a mill reducer, a reducer foundation slab and a mill foundation frame which are sequentially connected, wherein a packer is arranged between the reducer foundation slab and the mill foundation frame. The application method comprises the following steps: 1) putting the reducer foundation slab on the mill foundation frame, adjusting a leveling bolt to generate a certain distance between the reducer foundation slab and the mill foundation frame; 2) putting a protecting sleeve and a locating taper pin; 3) sealing the periphery of the reducer foundation slab by a baffle plate on the periphery of the reducer foundation slab; 4) pouring the packer, and 5) fixedly connecting the mill reducer, the reducer foundation slab and the mill foundation frame together through the connection of the reducer a bolt. The installation structure body disclosed by the invention has the advantages of conveniently dismantling, easily leveling the reducer foundation slab and the like compared with the prior art because the reducer foundation slab is movably connected with the mill foundation frame.

The invention discloses a cold stamping one-time forming bearing chamber bearing seat and a production method thereof, which comprises a bearing seat upper seat 1, a base 2, a bearing chamber 4, a sealing cover 3, fixing bolts, etc., and the edge 13 of the sealing cover is high on both sides and low in the middle. structure, so that the sealing cover 3 is tightly buckled and pressed in the original bearing chamber 4, and it is not easy to fall off. The bearing chamber 4 is tightly installed in the bearing seat cavity 11 surrounded by the bearing seat upper seat 1 and the base 2, and the bearing is installed in the center of the bearing chamber 4 and the sealing cover 3; the bearing seat upper seat 1 and the base 2 are provided with bolt holes; It can be fixed with the corresponding mechanical bolt holes. Because the bearing seat is produced by cold stamping technology, the bearing seat has a large pressure bearing capacity. It not only has the precision and firmness of the cast bearing seat, but also has a simple process and high toughness, which is not easy to break. It also plays a dust-proof role and prolongs the service life of the bearing. .

The invention provides a clothesline with adjustable suspension rings. The clothesline comprises a clothesline body, wherein a plurality of suspension-ring devices are arranged on the clothesline body; each suspension-ring device comprises a line clamp and ring bodies arranged on the line clamp, and the line clamps clamp the clothesline body. The clothesline provided by the invention is provided with the suspension-ring devices with the line clamps, when the line clamps are loosened, the positions of the suspension rings can be adjusted, the positions of the suspension rings are convenient and flexible to adjust, the problem that the suspension rings on the clotheslines in the prior art cannot be adjusted is solved, and besides, because two ring bodies are symmetrically arranged on each suspension-ring device, the line clamps can be evenly stressed and have low probabilities of getting loose and falling off.

The invention discloses soft rhombic monofilament artificial turf. The turf comprises rhombic grass filaments with rhombic cross sections, wherein the rhombic grass filaments are mounted and inserted in a base layer, the base layer comprises a rubber layer, a felt layer is arranged under the rubber layer, the lower side of the felt layer is connected with a PU (polyurethane) cushion layer, the lower surface of the PU cushion layer is coated with a back gum layer, pits are formed in positions, corresponding to mounting and inserting positions of the rhombic grass filaments, of the lower surface of the PU cushion layer, and anti-falling tightening rings are arranged at roots of lower ends of the rhombic grass filaments and arranged at the pits. The invention further discloses a preparation method of the soft rhombic monofilament artificial turf. The grass filaments of the turf are soft, the toughness and the elasticity are good, the grass filaments are mounted and inserted firmly and cannot loose and fall off easily, and sport injuries such as skin scratches, sprains and contusions of feet and the like can be effectively reduced.

The invention discloses a bent radio frequency connector housing, which comprises a main shell and an auxiliary shell, wherein the main shell is a stepped shaft structure with one larger end and a smaller end, an axial through hole with the stepped structure is arranged in the main shell, an annular press-fitting table is arranged inside the small end of the main shell, an annular positioning table is arranged outside the small end of the main shell, and an axial through groove is arranged on one side of the outer peripheral surface of the small end of the main shell; An inner side of the horizontal through hole of the upper end of the sub-shell is interference-fitted with an annular press fitting table, an annular positioning groove is arranged on the outer side of the horizontal throughhole of the upper end of the sub-shell, the annular positioning table is embedded in the annular positioning groove, and the vertical through hole of the lower end of the sub-shell is vertically communicated with the axial through hole of the main shell through the axial through groove. The invention has the advantages of simple structure, low cost and convenient operation. The two-stage fixed structure provides double safety for the connection of the main shell and the auxiliary shell, which ensures that the connection of the main shell and the auxiliary shell is stable and reliable, and is not easy to loose and fall off, so as to ensure the normal transmission of the radio frequency signal.

The invention relates to an automatic fastening screw provided with a hollow outer screw body. An outer thread is arranged on the outer screw body. A hollow outer screw cap is arranged on the upper portion of the outer screw body. An expansion sheet is arranged in a cavity of the outer screw body. A V-shaped groove is formed in the upper end of the expansion sheet. Expansion grooves are formed in the side face of the outer screw body in the manner of being matched with the expansion sheet so that the expansion sheet can stretch out of the expansion grooves during expanding. A solid inner screw body is further arranged in a hollow structure of the outer screw cap and the outer screw body, a convex inner screw body sharp end is arranged at the bottom end of the inner screw body, and the inner screw body sharp end right faces the center of the V-shaped groove. A thread is arranged on the outer side of the inner screw body sharp end, and the inner screw body sharp end is rotationally fixed in the cavity of the outer screw body through a nut arranged in a matched manner. The top end of the inner screw body is connected with the inner edge of the outer screw cap through a connecting key, and a screw groove used in cooperation with a screwdriver is formed in the top end of the inner screw body. The automatic fastening screw can be firmly fixed inside a fixed object, and loosening and falling off are not prone to happening on occasions where shaking often happens.