CN106815435A - A kind of preparation method of biomimetic type automobile tail fin shell - Google Patents

Abstract

The present invention relates to a kind of preparation method of biomimetic type automobile tail fin shell, including：(1) collection of sparrow mouth feature：By sparrow mouth vertical section outline Drawing of Curve in the directrix equation (formula 1 1) of contour curve on the vertical section on graph paper, fitting sparrow mouth

Description

A kind of preparation method of biomimetic type automobile tail fin shell

Technical field

The present invention relates to a kind of automobile tail fin, and in particular to a kind of preparation method with biomimetic type automobile tail fin shell.

Background technology

Automobile tail fin increasingly obtains liking and high praise for masses as the function of automobile with decoration.Tail fin has release The functions such as electrostatic, amplification communication signal, flow-disturbing, raising gps system precision, while having radio FM antennas, GSM communications day concurrently Line, gps antenna etc. are acted on；Tail fin can also effectively eliminate the pneumatic noise of air, make traveling quieter, show luxurious, vertical Body individual character.During dry weather, cosmetic vehicle is also easy to produce electrostatic, discharges quiet by installing the bar chain mode that mops floor at blast pipe when previous Electricity, after having tail fin antenna, this problem has obtained efficient solution, and tail fin antenna makes full use of electronics to walk the characteristic at tip, will Electrostatic Electron imported into the tail point of tail fin and discharges.Conventional automobile tail fin mainly has rod-type and shark fin type.

Automobile tail fin as body shape important component, it determines a makings for automobile to a certain extent With individual character, while it is again influence automotive aerodynamics, fuel economy, one of key factor of dynamic property.Research shows, Automobile its main resistance when running at high speed is air drag.When automobile is travelled with the speed of 80km/h, the work(of engine 60% Rate is used for overcoming air drag；When automobile is travelled with the speed of 150km/h, its air drag is 2-3 times of rolling resistance.Such as Body drag coefficient reduction by 10%, then can save fuel oil 7% or so.Bodywork surface annex, eyelet, groove and gap etc. are drawn The air-flow interference drag for rising accounts for the 5%~16% of total air drag.Tail fin is placed in outside automobile as important surface attachment is naked In air flow field, the resistance caused by it is the 2%-5% of vehicle air drag, while changing the air stream near covering for roofs .This means the dynamic property and fuel economy of vehicle can be effectively improved by optimizing tail fin geometry.

Tail fin, if reasonable in design, can effectively eliminate the whistle of air-flow generation as the direct part with air contact Consonant, while showing automobile makings.The shark formula tail fin that automobile tail fin popular at present is designed for Bayerische Motorne Werke Aktiengeellschaft, its inspiration From shark fins.Shark fins can improve vehicle body entirety cleanliness, while playing a part of to receive signal.However, experiment table Bright, shark formula tail fin can not show good aerodynamic performance in wind tunnel test, and main cause is shark formula tail Fin in design primary concern is that its appearance and modeling and signal are received, not excessive its aerodynamic performance of consideration. In addition, shark is aquatic animal, its tail fin may have good reducing noise and drag performance (i.e. with good fluidity in water Can), but the air dynamic behaviour that may not be had in atmosphere.

By the evolution of 1 years, with good adaptive capacity to environment, this was the innovation and creation of the mankind to nature biotechnology There is provided inspiration, Bionic Design can allow vehicle body more visual impact and aesthetic feeling, at the same the man and nature that can further away from From having annotated getting along amiably and peacefully for man and nature to a certain extent.The sparrow of title of " native place thief " is have by prolonged raw Thing is evolved can fly kind jump, be active in one's movements, and research shows that its mouth is presented certain by prolonged biological evolution in flight Geometry, can substantially reduce air drag makes its freely circle in the air.Therefore, it is necessary to " Bionic Design " theory is applied into vapour In the design of tailstock fin, a kind of biomimetic type automobile tail fin shell is researched and developed, increase the property such as sound insulation and noise reduction, the air conducting of vehicle Energy.

The content of the invention

It is an object of the invention to provide a kind of simple structure, moulding streamline, aesthetic in appearance, air resistance coefficient it is small, can be every Biomimetic type " sparrow mouth formula " automobile tail fin shell of sound noise reduction, the shell can improve the fuel economy of automobile, reduce vapour The running resistance of car.

To achieve the above object, a kind of bionical automobile tail fin shell with sparrow mouth geometric properties of the present invention Preparation method, comprise the following steps：

1st, the collection of sparrow mouth feature：Obtain some adult sparrows, and filter out mouth feature completely it is exposed outside, The complete sparrow of profile, cuts sparrow mouth after being processed through surface cleaning, takes mouth, is cut open along center line, by sparrow mouth vertical profile Face outline Drawing of Curve is on graph paper；The sparrow mouth feature vertical section outline curve of drafting has two, that is, go up profile Curve and bottom profiled curve, the directrix equation of contour curve on the mouth feature vertical section of sparrow is gone out with least square fitting (formula 1-1)

2nd, the foundation of tail fin shell bionic model：The directrix equation of contour curve on the vertical section of step (1) is imported SolidWorks, forms bionical curve EF, crosses E points and sets up datum level X=151 perpendicular to bionical curve EF positions, in this base The first profile line L is set up in quasi- face；The first round profile L is symmetrical on EV；First round profile L, left-half was by first Circular arc EP, the second circular arc PQ, three-arc SQ, the 4th circular arc TU, be arranged between three-arc SQ and the 4th circular arc TU One straight line ST and the second straight line UV compositions being arranged on datum level X=151；Cross F points and is set up in datum level Y=0 planes Two contour line M, the second contour line M are semicircle, and left and right is symmetrical on FY, the second contour line M right half parts by 5th circular arc FW and the 3rd straight line YW compositions being arranged on datum level X=151；By first round profile L along bionical curve EF, straight Line VY is to constitute preliminary bionic model to the second contour line M setting-outs；Further to expand the application of automobile tail fin of the present invention Scope, make that automobile tail fin fits with roof more closely, set up first round profile L and the second contour line M in step (2) and put After sample boss, cutting profile line is set up in the plane of datum level Z=0；The cutting wheel profile is by the 6th circular arc HJ, and the 4th is straight Line HK and the 5th straight line KJ is constituted；The 6th circular arc HJ can be adjusted according to different vehicles, then carry out boss cutting, Constitute the bionic model of bottom cutting；In order to further reduce the air resistance coefficient of automobile tail fin, can be to making ready-made tail fin Cover top portion carries out fillet cutting process, and concrete operation method is：Fillet cutting profile is set up in the plane of datum level Z=0 Line；The fillet cutting wheel profile is made up of the 7th circular arc XZ, the 6th straight line XB and the 7th straight line BZ, then carries out boss and cuts Cut, finally carry out taking out shell treatment again, form hollow bionic caudal fin shell model.

3rd, the preparation of tail fin shell：The bionic model built up according to step (2) makes corresponding mould, is then prepared Or the bionic model that will directly make is input into computer, is printed using 3D printer.

To reduce tail fin quality, bending stiffness, torsional rigidity and the Modal Performances of tail fin shell, the step (3) are improved Carry out using carbon fiber enhancement resin base composite material during Mold Making, carbon fiber is formed using three layers of fiber mixing laying； Wherein, three layers of fibrage laying angle from top to bottom is [90/45/0], and 0 degree direction is tail fin transverse direction.

Advantages and positive effects of the present invention：

1st, the present invention is applied in the directrix of automobile tail fin vertical section by by sparrow mouth vertical section outline curve, makes system The bionic caudal fin shell vertical section directrix of work has variable curvature characteristic, and radius of curvature comb is presented the variation tendency for gradually increasing； Meanwhile, by the design to contour line L and the specific curves of contour line M, make automobile tail fin that there is good air dynamic behaviour, Air resistance coefficient is small, and air conducting is good, can be obviously improved fuel economy and overall cleanliness, preferably plays sound insulation and noise reduction Effect, improves riding comfort.

2nd, tail fin shell of the present invention can be printed directly after model has been set up using 3D printer, prepare work Skill is simple.Meanwhile, the present invention can also be processed making by the mould that be matched with bionic model of making, with Mold Making During, raw material can use bio-based materials, i.e., put leaf and bamboo fibre using the hemp in string, sisal hemp, jute, palm fibre Etc. extraordinary reinforcing material, it is combined with degradable matrix material can be made into can be degradable " Green Composites ", Automobile more green, environmental protection can so be made.

3rd, the curve of the present invention composition contour line L, M is the circular arc or straight line for determining curvature, and this had both dropped to a certain extent The technology difficulty coefficient of low 3D printing has taken into account the fuel economy of automobile again, makes the solid object surface moulding streamline of making, outer Type is attractive in appearance.And, the sparrow mouth vertical section outline curve that biomimetic type automobile tail fin can be as needed to fitting stretched, Scaling, so as to design various sizes of biomimetic type automobile tail fin, the need for meeting different automobile types.

4th, can replace traditional using carbon fiber enhancement resin base composite material when the automobile tail fin that the present invention makes makes Plastics tail fin, effectively reduces tail fin quality, and carbon fiber using three layers of fibrage, and laying angular arrangements from top to bottom are [90/45/0], bending stiffness, torsional rigidity and Modal Performances of tail fin shell etc. are improve, is increased the service life.

Brief description of the drawings

Fig. 1 is sparrow mouth feature vertical section outline curve；

Fig. 2 is the sparrow mouth vertical section outline curve and its Curvature varying form after fitting；

Fig. 3 is the schematic diagram that tail fin shell bionic model of the present invention is set up；

Fig. 4 is the schematic diagram of first round profile L；

Fig. 5 is the schematic diagram of the second contour line M；

Fig. 6 is the front view of biomimetic type automobile tail fin model；

Fig. 7 is the schematic diagram of cutting wheel profile when biomimetic type automobile tail fin bottom is cut；

Fig. 8 is the schematic diagram of biomimetic type automobile tail fin top fillet cutting profile；

Fig. 9 is that tail fin shell bionic model top of the present invention carries out the schematic diagram after fillet cutting；

Figure 10 is the schematic diagram of carbon fiber layer ply stacking-sequence.

Specific embodiment

To make those skilled in the art be clearly understood that technical scheme of the present invention and its advantage and effect, with reference to attached The present invention is described in detail for figure.

Embodiment 1

The preparation method of the bionical automobile tail fin shell with sparrow mouth geometric properties of the present invention, including it is following Step：

(1), the collection of sparrow mouth feature：Obtain some adult sparrows, and filter out mouth feature completely it is exposed Outward, the complete sparrow of profile, cuts sparrow mouth after being processed through surface cleaning, takes mouth, is cut open along center line, and sparrow mouth is indulged Cross-sectional outer exterior feature Drawing of Curve on graph paper (see Fig. 1)；The sparrow mouth feature vertical section outline curve of drafting has two, Contour curve O and bottom profiled curve I is gone up, then goes out contour curve O on mouth feature vertical section with least square fitting Directrix equation (formula 1-1)；

(2), the foundation of tail fin shell bionic model：The directrix equation of contour curve O on the vertical section of step (1) is imported SolidWorks, contour curve O (see Fig. 2) in formation, upper contour curve O have variable curvature characteristic, and radius of curvature comb is presented The variation tendency for gradually increasing, bionical curve EF (see Fig. 3) is set to by upper contour curve O, crosses E points and perpendicular to bionical curve EF Datum level X=151 is set up in position, and the first profile line L is set up in this datum level；The first round profile L is right on EV or so Claim；First round profile L left-halfs by the first circular arc EP, the second circular arc PQ, three-arc SQ, the 4th circular arc TU, be arranged on First straight line ST between three-arc SQ and the 4th circular arc TU and be arranged on datum level X=151 second straight line UV compositions (see Fig. 4)；Cross F points and set up the second contour line M in datum level Y=0 planes, the second contour line M is semicircle, and left and right is closed Symmetrical in FY, the second contour line M right half parts are by the 5th circular arc FW and the 3rd straight line being arranged on datum level X=151 YW is constituted (see Fig. 5)；By first round profile L along bionical curve EF, straight line VY to the second contour line M setting-outs be constitute it is preliminary bionical Model；

Process is simple during for the moulding streamline, the aesthetic in appearance and follow-up 3D printing that ensure institute's bionic caudal fin shell model, The first round profile L, the part of the second contour line M are the circular arc or straight line for determining curvature；Meanwhile, it is further to reduce Air resistance coefficient, it is of the invention by the test of many times to first round profile L of different shapes and the second contour line M of different shapes, It is final to determine：First circular arc EP parameters are the center of circle (0, -51), E (0, -58), P (6.5, -51), radius 6.5；Second circular arc PQ joins Number is the center of circle (59, -53), P (6.5, -51), Q (43, -3), radius are 53；Three-arc SQ parameters are the center of circle (43, -2), S (44, -2), Q (43, -3), radius are 1；4th circular arc TU parameters are the center of circle (43, -1), T (44, -1), U (43,0), radius are 1；First straight line ST parameters are S (44, -2), T (44, -1)；Second straight line VU parameters are first that U (43, -0), V (0,0) are constituted Contour line L and the 5th circular arc FW parameters are the center of circle (8,0), F (0,0), W (8, -8), and the 3rd straight line YW parameters are Y (8,0), W (8, -8) manufacture craft is most simple during the bionic model 3D printing of the second contour line M setting-outs for constituting, and air resistance coefficient is minimum, Air conducting is best.Above-mentioned first round profile L, the second contour line M coordinate value a little be it in respective datum level Value, its value in global coordinate system is not represented.

(3), the preparation of tail fin shell：The bionic caudal fin shell model built up according to step (2), it is direct using ABS resin Printed with 3D printer.

Embodiment 2

Step (1) is with step (2) with embodiment 1；

Step (3), the preparation of tail fin shell：The bionic caudal fin shell modelling built up according to step (2) is matched Mould, be then prepared using carbon fiber enhancement resin base composite material, carbon fiber used is to use three layers of fiber to mix Laying is closed to form；Wherein, three layers of fibrage laying angle from top to bottom is [90/45/0] (see Figure 10), and 0 degree direction is tail fin Laterally.

Embodiment 3

In order to reduce the air resistance coefficient of automobile tail fin, the range of application of bionic caudal fin is further expanded, present invention design Automobile tail fin bionic model bottom can need any cutting according to vehicle, tighter its purpose is to allow tail fin to be fitted with roof It is close；Meanwhile, fillet cutting process can be carried out to bionic model top, making carries out the biomimetic type of fillet treatment and bottom cutting Automobile tail fin shell, specifically includes following steps：

Step (1) is with embodiment 1；

Step (2), after first round profile L and the second contour line M and setting-out boss has been set up, in the flat of datum level Z=0 Cutting profile line is set up in face；The cutting wheel profile is made up of (see figure the 6th circular arc HJ, the 4th straight line HK and the 5th straight line KJ 7)；For example：For the automobile tail fin outer casing bottom for enabling making is fitted tightr with A0 grades of roof, put on the basis of F and set up Cutting wheel profile, wherein, the 6th circular arc HJ parameters are：The center of circle (79,3528), H (- 15, -4), J (173, -4), radius 3534； 4th straight line HK parameters are：H (- 15, -4), K (75,42)；5th straight line KJ parameters are：K (75,42), J (173, -4)；Meanwhile, Set up fillet cutting wheel profile in the plane of datum level Z=0, the fillet cutting wheel profile is by the 7th circular arc XZ, the 6th straight Line XB and the 7th straight line BZ compositions are (see Fig. 8)；For example：7th circular arc XZ parameters are：The center of circle (146, -51), X (145, -57), Z (151, -51), radius 5.5；6th straight line XB parameters are：X (145, -57), B (151, -58)；7th straight line BZ parameters are：B (151, -58), Z (151, -51)；The 6th circular arc HJ can be adjusted according to different vehicles, and boss cutting is carried out afterwards, Then carry out taking out shell treatment again, form hollow bionic caudal fin shell model (see Fig. 9).

Step (3) is with embodiment 1.

Experimental performance is tested

Wind tunnel test shows：The biomimetic type automobile tail fin made using method of the present invention will can be produced during traveling Raw whistle sound control system alleviates the diseases such as the headache caused by high-decibel noise, tinnitus, failure of memory below 30 decibels, effectively Shape.However, the noise that orthodox car tail fin sends typically is required no more than 80 decibels.Meanwhile, the present invention proves energy by testing The design that it is critical only that bionical curve EF that air resistance coefficient is small, makes it possess good air dynamic behaviour is enough substantially reduced, it is right Although air resistance coefficient can be reduced using the design parameter of the setting of embodiment 1 in first round profile L and the second contour line M, enter one Step improves air dynamic behaviour, but first round profile L and the second contour line M is simultaneously little to the overall influence of tail fin shell.

Additionally, being applied jointly in wind tunnel test with existing shark formula tail fin using the biomimetic type automobile tail fin that the present invention makes On, the present invention can reduce air drag 0.6%-0.8% compared with shark formula tail fin.

The present invention can carry out entirety to model as needed using the automobile tail fin that the above method makes in modeling process Flexible, scaling, so as to design various sizes of biomimetic type automobile tail fin, the need for making it meet different automobile types.

Claims (2)

1. a kind of preparation method of biomimetic type automobile tail fin shell, it is characterised in that：Specifically include following steps：

(1), the collection of sparrow mouth feature：Obtain some adult sparrows, and filter out mouth feature completely it is exposed outside, outward The complete sparrow of shape, cuts sparrow mouth after being processed through surface cleaning, takes mouth, is cut open along center line, by sparrow mouth vertical section Outline Drawing of Curve is on graph paper；The sparrow mouth feature vertical section outline curve of drafting has two, that is, go up profile bent Line and bottom profiled curve, the directrix equation (formula of contour curve on the mouth feature vertical section of sparrow is gone out with least square fitting 1-1)

$\begin{array}{c}x=0.445t+7.742t^{0.5}\\ y=0.333t-4.073t^{0.5}\end{array},t\∈\left(\begin{array}{cc}0& 150\end{array}\right)---(1-1);$

(2), the foundation of tail fin shell bionic model：The directrix equation of contour curve on the vertical section of step (1) is imported SolidWorks, forms bionical curve EF, crosses E points and sets up datum level X=151 perpendicular to bionical curve EF positions, in this base The first profile line L is set up in quasi- face；The first round profile L is symmetrical on EV；First round profile L, left-half was by first Circular arc EP, the second circular arc PQ, three-arc SQ, the 4th circular arc TU, be arranged between three-arc SQ and the 4th circular arc TU One straight line ST and the second straight line UV compositions being arranged on datum level X=151；Cross F points and is set up in datum level Y=0 planes Two contour line M, the second contour line M are semicircle, and left and right is symmetrical on FY, the second contour line M right half parts by 5th circular arc FW and the 3rd straight line YW compositions being arranged on datum level X=151；By first round profile L along bionical curve EF, straight Line VY is to constitute preliminary bionic model to the second contour line M setting-outs；After preliminary tail fin model is obtained, datum level Z=0's Cutting profile line is set up in plane carries out bottom cutting to model；The cutting wheel profile is by the 6th circular arc HJ, the 4th straight line HK And the 5th straight line KJ composition, the 6th circular arc HJ is adjusted according to different vehicles；Then in the plane of datum level Z=0 Fillet cutting wheel profile is inside set up, the fillet cutting wheel profile is by the 7th circular arc XZ, the 6th straight line XB and the 7th straight line BZ groups Into, boss cutting is carried out afterwards, finally carry out taking out shell treatment and obtain hollow bionic caudal fin shell model；

(3), the preparation of tail fin shell：The bionic model built up according to step (2) makes corresponding mould, is then prepared, Or the bionic model that will directly make is input into computer, is printed using 3D printer.

2. the preparation method of a kind of biomimetic type automobile tail fin shell according to claim 1, it is characterised in that：Step (3) When the making of tail fin shell is prepared using mould, it is prepared with carbon fiber enhancement resin base composite material, carbon fiber used It is to be formed using three layers of fiber mixing laying；Wherein, three layers of fibrage laying angle from top to bottom is [90/45/0], and 0 degree just To being tail fin transverse direction.