29results about How to "Reduce drag coefficient" patented technology

The invention relates to the technical field of communication, in particular to mobile 5G communication base station equipment. According to the technical scheme, the communication equipment comprises an electric lifter and a communication equipment body, a first fixing block is fixedly installed on the electric lifter, a first rotating block is hinged to the first fixing block, a first electric push rod is fixedly installed on the first rotating block, a second rotating block is fixedly installed on the first electric push rod, and a third rotating block is fixedly installed on the electric lifter; the electric elevator further comprises a first stabilizing mechanism used for stabilizing the first rotating block, a second electric push rod is arranged on the first stabilizing mechanism, a second stabilizing mechanism used for stabilizing the electric elevator is arranged on the second electric push rod, and a limiting transverse plate wraps the peripheral surface of the first fixing block, so that the limiting effect is achieved; and a third electric push rod is unfolded to drive a connecting plate to move, so that a clamping plate is driven to move, the clamping plate is fixedly clamped on the electric elevator, and the stability of the electric elevator is improved.

The invention discloses a bulk cargo ship cargo hold cover and a bulk cargo ship, the bulk cargo ship cargo hold cover comprises a hatch cover and a hatch coaming, the hatch cover is arranged above an exposed deck, and the hatch coaming is embedded in the exposed deck; a first pressing strip is arranged on the exposed deck, and a first sealing part is arranged at the bottom of the hatch cover; a second pressing strip is arranged on the hatch coaming panel, and a second sealing part is arranged at the bottom of the hatch cover; a hatch cover skirt plate is fixedly arranged at the bottom of the hatch cover and arranged between the first sealing component and the second sealing component. And an inflatable pressing part is arranged on the hatch coaming vertical plate. The cargo hold cover of the bulk cargo ship has the advantage of multi-point watertight protection.

The utility model belongs to the technical field of grating screens, particularly relates to an LED grating screen, and aims to solve the problems that an existing spring pin is arranged on the back face and needs to be pulled to move during disassembly, when the density of light bars is large, the distance is reduced, the spring pin is inconvenient to pull, a power source is connected with the light bars through wires, the installation difficulty is increased, and use is inconvenient. According to the technical scheme, the LED lamp comprises a plurality of LED lamp strips, two first aluminum back strips are fixedly arranged on one sides of the LED lamp strips, two second aluminum back strips used for being fixed to a wall are arranged on one sides of the two LED lamp strips, and a # shape is formed between the two second aluminum back strips and the two first aluminum back strips; according to the LED lamp strip, the first aluminum back strip and the second aluminum back strip are fixed together through the first clamping block and the second clamping block, the position is convenient to adjust, meanwhile, a plurality of LED lamp strips can be electrically connected through a plurality of three-way wire rows and flat cables, so that the LED lamp strips are convenient to connect and do not need to be connected through additional wires, and the installation efficiency is improved.

This utility model provides a front wheel dam and a vehicle, belonging to the field of automotive parts technology. It includes a dam positioned in front of the vehicle's front wheel, with a guide vane at its bottom edge. The bottom end of the guide vane is inclined towards the front wheel, and a vertically positioned flap is located at the bottom of the guide vane. This utility model can guide airflow, preventing it from directly impacting the wheels, while also reducing the drag of the dam itself, thus helping to reduce the vehicle's drag coefficient.

The utility model discloses an air disinfection module, and relates to the technical field of air disinfection. The device comprises a frame body; the air inlet grille is made of a light guide material and is arranged on the inner side of the frame body in a striding manner, and a photocatalyst is sprayed on the surface of the air inlet grille; and the LED lamps are arranged on the frame body and abut against the peripheral side of the air inlet grille so as to guide light emitted by the LED lamps into the air inlet grille, so that the photocatalyst on the surface of the air inlet grille fully reacts, and air passing through the air inlet grille is killed. The air inlet grille comprises a plurality of air inlet faces arranged in parallel, and the LED lamps are arranged in multiple sets and correspondingly abut against the side faces of the air inlet faces. By adopting the technical scheme, the photocatalyst has the advantages of sufficient reaction, good disinfection effect and low cost.

The application provides a solid-state laser radar built in a vehicle headlamp and a point cloud processing method, comprising: a vehicle lamp shell, which is internally separated into an illumination cabin and a radar cabin, and a heat insulation layer is arranged between the illumination cabin and the radar cabin; a solid-state laser radar is arranged in the radar cabin and comprises a VCSEL emission array, a SPAD receiving array and a signal processing and control circuit; a heat dissipation layer is arranged in the radar cabin; based on the above structure, the application provides a solid-state laser radar point cloud processing method built in a vehicle headlamp, wherein the solid-state laser radar is two, a first solid-state laser radar installed in a left front vehicle lamp and a second solid-state laser radar installed in a right front vehicle lamp, which can not only improve the field of view range, but also form a field of view overlapping area in front of the vehicle, so that the point cloud monitoring density and accuracy in the overlapping area are significantly improved.

The glass trough comprises a first section, a second section and a third section, the first section is arranged on the inner side surface of corner window glass, the second section is connected to the first section and extends in the direction away from the corner window glass, the second section is connected with the third section, and the first section, the second section and the third section define a guide sliding groove. The end, away from the corner window glass, of the second section extends towards the direction where the saddle is located. The glass trough can be installed on the vehicle door and is in sliding connection fit with the side door glass through the guide sliding groove, an outwards-protruding decoration strip does not need to be installed, the zero-section-difference design of the corner window portion of the vehicle door is achieved, the wind resistance coefficient of the vehicle is reduced, and the performance of the vehicle is improved. The end, away from the corner window glass, of the second section extends towards the direction where the saddle is located, so that passengers can obtain a wider view range through the corner window glass, and then the driving safety is improved.

The utility model discloses a propeller locking structure, a power assembly and an unmanned aerial vehicle, and belongs to the technical field of machinery. The propeller locking structure comprises an inner hexagonal screw, a spring gasket and a propeller locking gasket, the propeller locking gasket is provided with a first mounting hole, the hole wall of the first mounting hole is provided with a step, the step is used for placing the spring gasket, the bottom of the propeller locking gasket is further provided with a lower boss, and the lower boss is used for being embedded into a second mounting hole of the propeller from top to bottom; the motor shaft is used for being embedded into the second mounting hole from bottom to top; and the inner hexagonal screw is used for penetrating through the spring gasket and the first mounting hole and is fixedly connected with the motor shaft in the second mounting hole. According to the propeller locking structure, the power assembly and the unmanned aerial vehicle provided by the embodiment of the invention, the inner hexagonal screw and the spring gasket are assembled on the propeller locking gasket and are connected to the motor shaft, so that the propeller is fixed. The propeller locking structure has the advantages of being anti-loose, convenient to install, high in reliability, attractive, capable of reducing the wind resistance coefficient in the operation process of a power system, low in cost and the like.

The invention provides a commercial vehicle electric door, a system and a control method thereof. The electric vehicle door of the commercial vehicle comprises a vehicle door body which is rotatably connected with a vehicle body through a hinge; the electric limiting stopper is mounted on one side, corresponding to the hinge, of the automobile door body and is connected with the automobile body; the door lock is mounted on the other side, away from the hinge, of the vehicle door body and comprises a door lock body and a self-suction lock; the switch key part comprises an internal opening key and a central control key which are respectively mounted on the inner side of the vehicle door body, and an external opening key mounted on the outer side of the vehicle door body; the vehicle door controller is in communication connection with the electric limiting stopper, the door lock body, the self-suction lock, the internal opening key, the central control key and the external opening key through wire harnesses; and the control module is used for controlling the door lock body to perform unlocking or locking action, the door lock body to perform opening action, the electric limiting stopper to perform door opening or door closing action and the self-suction lock to perform door closing action.

The utility model discloses a geotextile positioning device for concrete guardrail maintenance, and belongs to the technical field of geotextile positioning. A geotextile positioning device for concrete guardrail maintenance comprises a device body, the device body comprises a rotating shaft, a first positioning piece and a second positioning piece which are hinged to each other are arranged at the rotating shaft, and the first positioning piece is provided with a first attaching part attached to the outer wall of the outer side of a concrete guardrail; the second positioning piece is provided with a second attaching part attached to the outer wall of the inner side of the concrete guardrail; the first positioning piece and the second positioning piece are each provided with a balance weight piece. The first attaching part of the first positioning piece is attached to the outer wall of the outer side of the concrete guardrail, and the second attaching part of the second positioning piece is attached to the outer wall of the inner side of the concrete guardrail, so that the geotechnical cloth covering the guardrail is fixed, and the phenomenon that the geotechnical cloth is not attached to the surface of the guardrail due to the influence of the external environment is prevented.

The utility model relates to a pair of combined glasses, which comprises a pair of main glasses and a pair of auxiliary glasses. The main glasses comprise a main glasses frame and main lenses connected to the main glasses frame, and the main glasses frame comprises a main glasses frame and glasses legs. The auxiliary glasses comprise an auxiliary glasses frame and auxiliary lenses connected to the auxiliary glasses frame. Wherein the auxiliary glasses frame is detachably connected to the inner side of the main glasses frame through a connecting piece, and the connecting piece extends in the direction of increasing the distance between the main glasses frame and the auxiliary glasses frame. The main mirror frame can have a large bending radian, and the wind resistance coefficient is reduced. The distance between the main glasses frame and the auxiliary glasses frame is increased through the connecting piece, so that the auxiliary glasses frame cannot abut against the inner side of the main glasses frame, bending deformation of the auxiliary glasses frame is avoided, in other words, the original radian of the myopic lenses serving as auxiliary lenses in the myopic glasses can be kept, and the imaging effect of the myopic lenses cannot be affected.

The utility model relates to the technical field of rainwater collection, and provides a motor home rainwater collection device which comprises a water tank and further comprises a filtering assembly arranged in the water tank, the filtering assembly comprises two clamping grooves which are formed in the centers of the opposite faces in the water tank, and clamping plates are movably arranged in the two clamping grooves; the two filter screen plates are fixedly arranged on the opposite surfaces of the two clamping plates; the collecting assembly is arranged on the outer surface of the water tank; the two filter screen plates are embedded into the water tank through the clamping plates, the two clamping plates are embedded into the clamping grooves, the stability of the two filter screen plates can be improved, the two filter screen plates are more stably embedded into the water tank, collected rainwater is filtered, a certain gap is formed between the two filter screen plates, impurities in the rainwater are better filtered, and the rainwater collecting efficiency is improved. The filtering openings of the two filtering net plates are different, and the filtering holes close to the lower ends are small, so that small impurities in rainwater are intercepted, and the cleanliness of the rainwater is improved.

The application belongs to the technical field of robots, and discloses a scalable amphibious robot driven by a paddle wheel, which comprises a shell, four wheel shafts rotatably connected to the shell and distributed on the left and right sides of the shell, four independent driving mechanisms arranged in the shell, four driving mechanisms connected with the four wheel shafts to drive the wheels to rotate independently, a scalable paddle wheel mechanism contained in the wheel mechanism, the scalable paddle wheel comprising a wheel, an independent small wheel body, a plurality of paddle plates and a scalable mechanism; the scalable mechanism is used for the expansion and contraction of the paddle plates of the paddle wheel, so that the paddle plates of the paddle wheel can be retracted into the wheel and form an integral whole with the wheel, or be expanded into a paddle wheel mechanism and be used for rowing. The single power driving system is combined with the scalable paddle wheel structure, so that the rigidity and flexibility of the hub are ensured when the amphibious robot runs on land, and the energy utilization efficiency is improved when the amphibious robot sails on water.

This invention relates to the field of overhead power transmission conductor technology, and in particular to a tenon-and-mortise interlocking ultra-high strength aluminum alloy steel core conductor and its preparation method. The conductor comprises an ultra-high strength steel core and an outer ultra-high strength aluminum alloy conductive layer. The ultra-high strength steel core is a G3A grade galvanized steel core, and the ultra-high strength aluminum alloy conductive layer is composed of 3-4 layers of S / Z type tenon-and-mortise interlocking wires concentrically stranded. The S / Z type tenon-and-mortise interlocking wires are a single-layer, single-wire concave-convex interlocking structure. This invention optimizes the Mg-Si-Zr-RE-B multi-element alloy composition system, achieving a Mg to Si mass ratio of 1.0-1.4, and combines this with a "solution-cold drawing-double-stage aging" process. This maintains high conductivity while increasing tensile strength to ≥360MPa, achieving an excellent match of high strength and high conductivity, and significantly improving strength while ensuring unchanged conductivity.

The invention discloses a wheel system and a vehicle, and relates to the technical field of automobile accessories and safety protection devices.The wheel system comprises a hub, a decorative cover and a thermal response contact assembly; the decorative cover is arranged on the outer side of the hub, is rotationally connected with a rim of the hub and can rotate relative to the hub; the thermal response contact assembly is arranged on the hub or the decorative cover, and when the temperature exceeds a preset temperature threshold value of the thermal response contact assembly, the hub and the decorative cover are in transmission connection through the thermal response contact assembly. The invention provides a wheel system which is simple in structure and high in reliability and does not need extra power supply support, and a brake overheating alarm function is realized through a mechanical method.

The invention relates to the technical field of charging piles, and discloses a mute device for a charging device, a mute charging device and an installation method.The mute charging device comprises the charging pile, a first access door is arranged on the left side of the charging pile, a second access door is arranged on the right side of the charging pile, and an air inlet silencing structure is arranged on the left side of the first access door; an air outlet noise reduction structure is arranged on the right side of the second access door. Noise is reduced by arranging the air inlet noise reduction structure and the air outlet noise reduction structure, and under the condition that the original structure and the heat dissipation effect of the charging pile are not changed, silent charging is achieved through the reasonably-arranged miniaturized and light silent equipment through the structure of the access door of the charging pile, and meanwhile the use experience of a user is improved.

The application provides a high altitude balloon launching method and a composite high altitude balloon. The high altitude balloon launching method comprises the following steps: putting the high altitude balloon into a windproof air bag, and connecting the high altitude balloon, a cable and a gondola in sequence; arranging winch pull ropes on the periphery of the windproof air bag, and arranging cutters on the winch pull ropes respectively; filling air into the windproof air bag and filling helium into the high altitude balloon, and controlling the pressure difference between the windproof air bag and the high altitude balloon within a preset pressure difference range after the filling is completed; releasing the windproof air bag and synchronously releasing the winch pull ropes; cutting the winch pull ropes by using the cutters when the distance between the gondola and the ground is greater than a first safety height; and detaching the windproof air bag to make the windproof air bag separate from the high altitude balloon when the distance between the gondola and the ground is greater than a second safety height. The high altitude balloon launching method and the composite high altitude balloon provided by the application aim to solve the problem that the wind resistance of the high altitude balloon is weak and the high altitude balloon is easy to be damaged in the launching process in the prior art.

The application discloses a trailer mounting method for a deep water test pool and relates to the technical field of deep sea engineering, which comprises the following steps: S1, basic frame manufacturing and installation: taking the center line of the on-site pool as the X-Y trailer installation reference, manufacturing and installing the basic frame; S2, X-Y trailer main body installation (including the wheel set); S3, drive device installation; S4, auxiliary trailer installation; S5, hydraulic brake system installation; S6, guide device installation; S7, cleaning device installation; S8, speed measuring device installation; S9, welding and fixing the buffer support according to the on-site actual measurement size, synchronously welding the front and rear buffer blocks of the X-Y trailer; installing the hydraulic buffer on the buffer support; S10, electric control cabinet positioning base and electric control circuit installation; and S11, power supply system installation: the slide wire is hung on the installation support through the insulator, and the carbon brush slider of the current collector on the main trailer is kept in close contact with the lower surface of the slide wire. The application effectively solves the installation problem caused by the space sealing of the laboratory through the step-by-step assembly scheme.

The invention relates to a framework structure of a flexible pipeline, the flexible pipeline and a machining method of the flexible pipeline, and the framework structure comprises a framework unit which is coaxially arranged with the flexible pipeline; the framework unit comprises a framework; the framework extends in the circumferential direction of the flexible pipeline to form a spirally-wound S-shaped interlocking structure. A gap is formed in the framework in the axial direction of the flexible pipeline; the shielding unit comprises a shielding body, the shielding body is wound along the inner side of the framework to form a spiral structure, the shielding body and the framework are embedded, and the shielding body is close to the side, where a medium is located, in the flexible pipeline; the shielding body comprises a body and a bending part, and the bending part extends to the gap. The shielding body is installed in the framework and can shield gaps of the pipeline framework, so that the flow-induced pulsation phenomenon is effectively restrained, the flow choking coefficient of a rough pipeline is reduced, and the conveying efficiency of a medium is improved; the problems of tedious operation, low inhibition effect and high cost in the prior art are solved.

The invention discloses a hub capable of reducing wind resistance, which comprises a hub part, a rim and a plurality of spokes connected with the hub part and the rim, a window is arranged between adjacent spokes, the window is strip-shaped, and the direction of the long axis of the window is the same as the radial direction of the hub; the spoke comprises a supporting part arranged on the front side of the spoke and a heat dissipation part arranged on the rear side of the spoke. The supporting part comprises a first supporting part, a second supporting part and a third supporting part connected with the first supporting part and the second supporting part, the first supporting part is fixed to the rim, and the second supporting part is fixed to the hub part; and the heat dissipation part is provided with wavy bulges. According to the hub, the window of the hub is arranged to be in the long-strip shape, meanwhile, the heat dissipation part is arranged at the spoke, the heat dissipation area is increased by arranging the wavy protrusions on the heat dissipation part, and the situation that the strength of the hub is affected due to long-term overheating of the hub is prevented.

This utility model relates to a wind-resistant vehicle body, comprising a main body consisting of a front fascia, side fascias, a roof, a floor, and a tailgate. The three sides of the roof facing away from the tail are curved beams with a smoothly transitioning curved surface structure. One side of the tail is a non-curved beam with a tail fin installed. Multiple teardrop-shaped air guides arranged in a predetermined direction are integrally formed on its corrugated plate. Curved columns are installed on both sides with extended end faces. After installation, these extended end faces overlap and connect with corresponding parts of the front and side fascias, forming a curved surface structure at the transition between the front and side fascias. An arc-shaped cover is installed at the junction of the curved columns and the roof, completely enclosing the junction to form a curved surface structure. This utility model, through the curved beams, curved columns, and arc-shaped cover forming multiple smoothly transitioning curved surface structures, effectively reduces airflow impact and eddies caused by traditional right-angle or acute-angle connections. The teardrop-shaped air guides guide the orderly flow of air from the roof, reducing turbulence interference.

This application relates to the field of vehicle component technology, and discloses a fixed glass assembly, a vehicle door, and a vehicle. The fixed glass assembly includes: a glass element; a bright strip frame having a first surface facing outwards along the width direction of the vehicle, the first surface including a first region and a second region distributed from front to rear along the length direction of the vehicle, the second region being recessed from the first region, at least the front edge of the inner surface of the glass element being fixed to the second region, and the outer surface of the glass element being flush with the first region; a support frame located on the edge of the inner surface of the glass element in a region not covered by the bright strip frame; the bright strip frame and the support frame are respectively used for connection with the door sheet metal of the vehicle door. The fixed glass assembly of this application, with its coordinated design of the bright strip frame and the glass element, eliminates the visual difference between the glass element and the vehicle body components, maintains the overall harmony of the vehicle's appearance, and also reduces wind noise and drag coefficient.

The utility model discloses a car door outer water cutting structure and a car, the car door outer water cutting structure comprises a car door outer plate assembly and an outer water cutting part arranged on the inner side of the car door outer plate assembly, the car door outer plate assembly comprises a car door outer plate and a connecting plate arranged on the inner side of the car door outer plate, the outer water cutting part comprises an outer water cutting part body, and the connecting plate is arranged on the outer side of the car door outer plate. The outer side of the outer water cutting body is connected with the connecting plate, a first supporting lip edge and a second supporting lip edge are arranged on the inner side of the outer water cutting body, the first supporting lip edge is connected with automobile door glass, and the end of the first supporting lip edge extends towards the top of the automobile door outer plate to abut against the automobile door outer plate. The second supporting lip edge is arranged below the first supporting lip edge and connected with the automobile door glass. The wind resistance coefficient of the automobile door can be effectively reduced, and the NVH performance of the whole automobile and the delicate appearance of the whole automobile are improved; the connecting plate arranged on the inner side of the automobile door outer plate can guarantee reliable connection between the automobile door outer plate and the outer water cutting strip.

The invention discloses a lower automobile body structure of an electric automobile. The lower automobile body structure comprises an automobile body lower assembly composed of a front cabin assembly, a battery pack assembly and a rear floor assembly. The front cabin assembly comprises a front longitudinal beam wheel cover assembly, and a front baffle lower cross beam is arranged on the front longitudinal beam wheel cover assembly. A battery pack front cross beam, a battery pack side edge beam and a battery pack rear cross beam are arranged on the side wall of the battery pack assembly; the rear floor assembly comprises a rear longitudinal beam wheel cover assembly; a rear floor front cross beam is arranged on the rear longitudinal beam wheel cover assembly; the front baffle lower cross beam is fixed with the battery pack front cross beam through a bolt, and the bolt is fixed with the battery pack rear cross beam through the rear floor front cross beam; the integration is high, the two independent units of the lower vehicle body and the battery pack are combined into a whole, and the number of parts and the weight of the vehicle body are reduced; a front floor assembly is omitted, the vehicle body tool development investment is reduced, and the whole vehicle development cost is reduced.

The invention relates to a hydrogen vehicle drag coefficient optimization method and device, a terminal and a storage medium. Comprising the following steps: 1, carrying out initialization design on a hydrogen vehicle wind resistance coefficient prediction device and preparing data required by wind resistance coefficient prediction; 2, performing hydrogen vehicle wind resistance coefficient prediction simulation analysis based on CFD simulation software to obtain whether the hydrogen vehicle wind resistance coefficient is within a set receivable range or not; 3, comparing and verifying a simulation result with existing wind tunnel experiment data; 4, performing optimization design on the hydrogen vehicle wind resistance coefficient which does not meet the requirement by utilizing aerodynamics; and 5, performing experimental verification and effect evaluation on the optimized scheme. By integrating computational fluid dynamics simulation, wind tunnel experiment data and real-time data acquisition and analysis technologies, the aerodynamic performance of the hydrogen vehicle can be comprehensively evaluated and optimized, the wind resistance coefficient can be reduced, meanwhile, the vehicle body shape can be optimized, the air resistance can be reduced, the energy efficiency performance of the hydrogen vehicle can be remarkably improved, and the energy efficiency and the endurance mileage can be improved.

The present invention discloses a multi-degree-of-freedom automobile active aerodynamics kit, including a multi-degree-of-freedom active rear wing, an active diffuser and an active front lip. The multi-degree-of-freedom active automobile rear wing is fixed on the trunk cover of a motor vehicle. The multi-degree-of-freedom active automobile rear wing includes a rear wing bottom plate, a rear wing main plate, an electric push rod and a slider. The rear wing bottom plate is used to be fixedly connected to the trunk cover of the motor vehicle. One end of the electric push rod is fixed to the rear wing bottom plate, and the other end is hinged to the slider. The slider is connected to the rear wing main plate. Compared with the prior art, by adding a multi-degree-of-freedom active rear wing, the rear wing can be raised, lowered and tilted according to different vehicle speeds and driving modes to meet the aerodynamic needs in various states, ensure the stability of the vehicle during driving, reduce the wind resistance coefficient during normal driving, and improve the cornering performance of the vehicle under high-speed driving.

The invention discloses an intelligent cleaning robot for a photovoltaic power station in a differentiated environment. The intelligent cleaning robot comprises a framework, an intelligent deviation correcting system, an upper transmission support, a lower transmission support, an upper housing and a lower housing. The framework is connected with the upper transmission bracket and the lower transmission bracket; the upper transmission support and the lower transmission support each comprise a transmission shaft and a multi-stage transmission structure, and the transmission shafts are connected with the integrated stepping motors and the driving walking wheels respectively. The intelligent deviation rectifying system comprises a deviation rectifying gyroscope and a control circuit; and the deviation rectifying gyroscope is integrated in a control circuit. The cleaning robot can cope with the distribution difference of the photovoltaic modules in different environments, precise distribution and control and efficient cleaning are achieved, the fault rate in the cleaning process is effectively reduced, and the cleaning effect and efficiency are improved.

The utility model relates to the technical field of vehicles, in particular to an automobile electric spoiler and an automobile with the same. According to the automobile electric spoiler, in the vertical direction of an automobile, a spoiler plate is provided with a first surface and a second surface which are arranged back to back, and the second surface is relatively located above the first surface; the second surface comprises a connecting surface and an arc surface which are connected in sequence, the arc surface is relatively located behind the connecting surface and extends towards the end relatively away from the connecting surface in the front-back direction of the automobile, and the end, away from the connecting surface, of the arc surface is bent upwards in the vertical direction of the automobile. The flow direction and speed of the air flow can be changed, so that the air flow can smoothly pass through the automobile body to reduce generation of vortex at the tail of the automobile, and therefore the wind resistance coefficient is reduced, and oil consumption or power consumption is reduced.