Automatically forming composite oblique grid storage tank and forming tool thereof

Abstract

The application discloses an automatic forming composite material oblique grid storage tank, which comprises an upper end cover, a lower end cover and an intermediate section; the intermediate section is connected with the upper end cover and the lower end cover respectively; the upper end cover and the lower end cover are both ellipsoidal; the intermediate section is a column section or a cone section and is provided with a round hole; the upper end cover, the intermediate section and the lower end cover all comprise an oblique grid formed by bidirectional spiral ribs and a skin; the center line of the outer surface of the bidirectional spiral ribs is an equi-pitch spiral line, an equi-helix-angle spiral line or a short-range line; and the center lines of the outer surfaces of the bidirectional spiral ribs of the upper end cover, the intermediate section and the lower end cover are smooth and continuous. The application further discloses a forming tool, which comprises a storage tank end cover silicone rubber grid mold formed by stereoscopic casting; a silicone rubber male mold is used as a mold; a proper cutting plane is selected so that the four corner distances of the storage tank end cover silicone rubber grid mold are equal to the cutting plane distance; and a pouring opening is arranged on one side of the silicone rubber male mold without a grid rib groove. The application has the advantages of simple structure forming process, low cost, light weight and suitability for automatic batch production.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of automatic forming of composite materials, and relates to an automatic forming composite material oblique grid tank and a forming tool thereof. BACKGROUND

[0002] In rocket structures, instrument cabins, post-modification cabins, satellite supports, inter-stage sections, head covers and the like have been designed as composite material structures, and good effects of large weight reduction have been obtained. The weight ratio of the tank structure in the rocket structure is larger, and the tank structure is designed as a composite material structure, so that the weight reduction effect will be better. Compared with the instrument cabin, the post-modification cabin, the satellite support, the inter-stage section and the head cover, the composite material tank needs to overcome many difficulties such as demolding, sealing, medium compatibility and the like. The low-temperature medium sealing problem also needs to be solved, and the design and automatic forming are more difficult. SUMMARY

[0003] The present application aims to overcome the above-mentioned defects, and provides an automatic forming composite material oblique grid tank and a forming tool thereof, which solve the technical problem of large design and automatic forming difficulty of the composite material tank in the prior art. The composite material grid tank is designed reasonably, low-temperature medium sealing is effectively realized, and low cost and light weight are realized.

[0004] To achieve the above-mentioned application purposes, the present application provides the following technical solutions.

[0005] The present application discloses an automatic forming composite material oblique grid tank and a forming tool thereof. The center lines of the outer contour surfaces of the bidirectional helical ribs are respectively ellipsoidal surfaces, cylindrical surfaces, pitch helixes, helixes with the same helix angle and geodesics. The helixes are smooth and continuous. The bidirectional helical ribs are symmetrical to each other. The bidirectional helical ribs are automatically and continuously wound, the helixes with the same pitch and the helixes with the same helix angle are automatically laid. The skin of the automatic forming composite material oblique grid tank is formed by combining automatic winding and automatic laying of the helixes with the same thickness. The present application is designed reasonably, has light weight and high strength. Meanwhile, the present application is combined with the process forming, and the composite material oblique grid tank is automatically formed by the special forming tool. The arc lengths of various ellipsoidal surface helixes are calculated for automatic winding, automatic laying and automatic cutting of the fiber tows of the composite material oblique grid tank. The corresponding soft mold forming device is designed to solve the problems of automatic continuous winding, automatic laying and forming of the structure. Different helical rib structures are selected according to different use conditions through comparison and design. The structure forming process is simple, the structure realizes low cost and light weight, and is suitable for automatic batch production.

[0006] An automatic forming composite material oblique grid tank comprises an upper end cover, a lower end cover and an intermediate section. The upper end and the lower end of the intermediate section are connected to the upper end cover and the lower end cover respectively. The upper end cover and the lower end cover are both ellipsoidal. The intermediate section is a cylindrical section or a conical section. The upper end cover and the lower end cover are provided with circular holes.

[0007] The upper head, the lower head and the middle section each comprise an inclined grid structure composed of bidirectional spiral ribs and a skin covering the outside of the inclined grid structure;

[0008] The center line of the outer profile of the bidirectional spiral rib is an equi-pitch spiral, an equi-helix-angle spiral or a geodesic, the center line of the outer profile of the bidirectional spiral rib of the upper head, the middle section and the lower head is smooth and continuous;

[0009] The bidirectional spiral rib with the center line of the outer profile being an equi-pitch spiral, an equi-helix-angle spiral and a geodesic is respectively referred to as an equi-pitch bidirectional spiral rib, an equi-helix-angle bidirectional spiral rib and a geodesic bidirectional spiral rib, the geodesic bidirectional spiral rib is automatically and continuously wound and formed, and the equi-pitch bidirectional spiral rib and the equi-helix-angle bidirectional spiral rib are automatically laid and formed.

[0010] Further, when the middle section is a column section, it is a cylindrical storage tank:

[0011] The ellipsoid profile equation of the upper head of the cylindrical storage tank is:

[0012]

[0013] wherein (x1, y1, z1) is the coordinate of any point in the coordinate system o1x1y1z1, and a and b are the long semi-axis length and the short semi-axis length of the ellipsoid profile respectively;

[0014] The geodesic parameter equation of the ellipsoid profile of the upper head of the cylindrical storage tank is:

[0015]

[0016] wherein (y1, z1) is the coordinate of any point on the y1o1z1 plane in the coordinate system o1x1y1z1, and φ1 is the included angle between the vector from the coordinate origin o1 on the y1o1z1 plane and the y1 axis, which satisfies the geodesic parameter equation of the ellipsoid profile of the upper head of the cylindrical storage tank;

[0017] The center line of the outer profile of one of the spiral ribs in the geodesic bidirectional spiral rib is an ellipsoid geodesic in the upper head and the lower head, and a cylindrical geodesic in the column section;

[0018] The ellipsoid geodesic bidirectional geodesic of the upper head of the cylindrical storage tank comprises two symmetrical geodesics, and the equation of one of the geodesics is:

[0019]

[0020] wherein θ1 is the included angle between the vector from the coordinate origin to the point (x1, y1) on the x1o1y1 plane and the x1 axis, θ1 of the ellipsoid geodesic, and α 短程线is the angle between the tangent of the ellipsoid generatrix at φ1=0 and the tangent of the ellipsoid brachistochrone at φ1=0; k is the ratio of the major axis to the minor axis of the ellipsoid, and the value range of k is [1.6, 2];

[0021] The coordinates of any point in the coordinate system o2x2y2z2 are (x2, y2, z2), and the cylindrical brachistochrone equation is:

[0022]

[0023] The length L of the cylinder segment is brought into the above equation set, and z2=L, and the angle difference Δθ2 between the upper and lower end points of the cylindrical brachistochrone can be calculated;

[0024] Where θ2 is the angle between the vector from the coordinate origin to point (x2, y2) on the x2o2y2 plane and the x2 axis, and R is the radius of the cylinder, R=a;

[0025] The ellipsoid surface equation of the lower head of the cylindrical storage tank is:

[0026]

[0027] Where (x3, y3, z3) are the coordinates of any point in the coordinate system o3x3y3z3;

[0028] The ellipsoid generatrix parameter equation of the lower head of the cylindrical storage tank is:

[0029]

[0030] Where (y3, z3) are the coordinates of any point on the y3o3z3 plane in the coordinate system o3x3y3z3, and φ3 is the angle between the vector from the coordinate origin o3 on the y3o3z3 plane and the y3 axis, which satisfies the ellipsoid generatrix parameter equation of the lower head of the cylindrical storage tank;

[0031] The ellipsoid brachistochrone equation of the lower head of the cylindrical storage tank is:

[0032]

[0033] Where θ3 is the angle between the vector from the coordinate origin to point (x3, y3) on the x3o3y3 plane and the x3 axis, is the θ3 of the ellipsoid brachistochrone;

[0034] The center line of the outer contour surface of one of the two helical ribs with equal pitch is an ellipsoid surface equal pitch helix on the upper head and the lower head, and a cylindrical equal pitch helix on the cylinder segment;

[0035] The ellipsoid equal pitch helix equation of the upper head of the cylindrical storage tank is:

[0036]

[0037] The equation of the equal-pitch helix of the cylindrical tank is:

[0038]

[0039] The equation of the equal-pitch helix of the ellipsoid head of the lower head of the cylindrical tank is:

[0040]

[0041] wherein, θ1 is the θ1 of the equal-pitch helix of the ellipsoid head of the upper head of the cylindrical tank; θ3 is the θ3 of the equal-pitch helix of the ellipsoid head of the lower head of the cylindrical tank; α 等螺距 φ1 is the angle between the tangent of the ellipsoid generatrix and the tangent of the equal-pitch helix of the ellipsoid head; k 柱等螺距 is the proportional coefficient between θ1 等螺距 and sinφ1, for the tank with the middle section being a cylinder section, the k 柱等螺距 of the upper head and the lower head of the tank is the same;

[0042] The outer contour surface center line of one of the equal-helix-angle double helical ribs is the equal-helix-angle helix of the ellipsoid head of the upper head and the lower head, and is the equal-helix-angle helix of the cylinder section;

[0043] The equation of the equal-helix-angle helix of the ellipsoid head of the upper head of the cylindrical tank is:

[0044]

[0045] The equation of the equal-helix-angle helix of the cylinder section of the cylindrical tank is:

[0046]

[0047] The equation of the equal-helix-angle helix of the ellipsoid head of the lower head of the cylindrical tank is:

[0048]

[0049] wherein, θ1 is the θ1 of the equal-helix-angle helix of the ellipsoid head of the upper head of the cylindrical tank; θ3 is the θ3 of the equal-helix-angle helix of the ellipsoid head of the lower head of the cylindrical tank; α 等螺旋角 φ1 is the angle between the tangent of the ellipsoid generatrix and the tangent of the equal-helix-angle helix of the ellipsoid head;

[0050] The coordinate system o1x1y1z1 takes the cylindrical tank rotation axis as the z1 axis, takes the intersection point of the z1 axis and the upper head ellipsoid and the cylindrical segment interface as the origin, the z1 axis points to the upper head top end from the origin, and the x1o1y1 plane is perpendicular to the z1 axis; the coordinate system o2x2y2z2 takes the cylindrical tank rotation axis as the z2 axis, the origin is the same as the coordinate system o1x1y1z1, the z2 axis is opposite to the z1 axis, and the x2 axis is coincident with the x1 axis; the coordinate system o3x3y3z3 takes the cylindrical tank rotation axis as the z3 axis, takes the intersection point of the z3 axis and the lower head ellipsoid and the cylindrical segment interface as the origin, the z3 axis is the same as the z2 axis, and the x3 axis forms an angle Δθ2 with the x1 axis, and the angle is positive when the x1 axis points to the x3 axis counterclockwise around the z3 axis; the three coordinate systems are all right-handed coordinate systems.

[0051] Further, when a = 400 mm, b = 250 mm; the cylindrical segment height L = 408 mm;

[0052] For the circular hole diameter of the upper head and the lower head being 250 mm, and the short-range line two-way spiral rib with the circular hole as the polar hole, α 短程线 = 18.20995686°;

[0053] For the ellipsoid surface equal-pitch spiral line with the starting point of the intersection between the upper head ellipsoid surface short-range line upper head and the cylindrical segment and the end point of the upper head circular hole being coincident, k 柱等螺距 = 87.20389426;

[0054] When the ellipsoid surface equal-pitch spiral line and the cylindrical surface equal-pitch spiral line are smoothly continuous, α 等螺距 = 67.67472979°.

[0055] Further, the starting point and the end point of the three kinds of intermediate segment cylindrical tank surface spiral lines are coincident;

[0056] The two-way spiral rib section is all a trapezoid which is mutually congruent, the trapezoid section geometric dimension is adjusted according to the bearing condition, and the height-width ratio value range The height-width ratio is preferably the golden section outer ratio 1.618; the trapezoid section is perpendicular to the outer surface center line of the two-way spiral rib, the trapezoid section center line points to the tank surface normal direction, the upper base and the lower base of the trapezoid section are respectively located on the tank inner surface and the tank outer surface, and the lower base midpoint sweeps along the outer contour surface center line of the two-way spiral rib to form the two-way spiral rib.

[0057] Further, when the intermediate segment is a cylindrical segment:

[0058] The skin is automatically laid according to the close-packed spiral line equation.

[0059] The ellipsoid surface equation of the upper head and the lower head is:

[0060] The equation of the close-packed helical line on the ellipsoid surface of the upper head of the cylindrical storage tank is:

[0061]

[0062] The equation of the close-packed helical line on the cylindrical surface is:

[0063]

[0064] The equation of the close-packed helical line on the ellipsoid surface of the lower head of the cylindrical storage tank is:

[0065]

[0066] φ0is the included angle between the tangent of the generatrix of the ellipsoid surface of the cylindrical storage tank and the tangent of the close-packed helical line on the ellipsoid surface when φ1is 0; θ1is the θ1of the close-packed helical line on the ellipsoid surface of the upper head of the cylindrical storage tank; θ3is the θ3of the close-packed helical line on the ellipsoid surface of the lower head of the cylindrical storage tank.

[0067] Further, when the middle section is a cone section, it is a conical storage tank:

[0068] The center line of the outer contour surface of one of the helical ribs in the short-range line bidirectional helical rib of the conical storage tank is a short-range line on the conical surface in the conical section, and the upper head and the lower head of the conical storage tank are an ellipsoid surface short-range line on the upper head of the conical storage tank and an ellipsoid surface short-range line on the lower head of the conical storage tank, respectively;

[0069] The equation of the short-range line on the conical surface is:

[0070]

[0071] where (x4, y4, z4) is the coordinates of any point in the coordinate system o4x4y4z4; z 下 is the distance from the conical vertex where the conical surface is located to the lower end surface of the truncated cone;

[0072] The distance z 上 from the conical vertex where the conical surface is located to the upper end surface of the truncated cone is substituted into the fourth equation of the above equation set to calculate the angle difference between the upper end point and the lower end point of the short-range line on the truncated conical surface

[0073] That is:

[0074] The equation of the ellipsoid surface of the upper head of the conical storage tank is:

[0075]

[0076] where (x5, y5, z5) is the coordinates of any point in the coordinate system o5x5y5z5;

[0077] The parametric equation of the generatrix of the ellipsoid surface of the upper head of the conical storage tank is:

[0078]

[0079] Where (y5,z5) are the coordinates of any point on the y5o5z5 plane in the coordinate system o5x5y5z5, and φ5 is the angle between the vector on the y5o5z5 plane originating from the origin o5 and the y5 axis. This angle satisfies the generatrix parameter equation of the ellipsoidal surface of the upper end cap of the conical tank.

[0080] The equation of the geodesic of the ellipsoidal surface of the upper head of the conical storage tank is:

[0081]

[0082] φ 5切 Let φ5 be the point where the generatrix of the conical surface is tangent to the elliptical generatrix of the ellipsoidal surface of the upper head of the conical tank. From equation number 4 above, the geodesic points φ5 = 0 and φ5 = φ on the ellipsoidal surface of the upper head of the conical tank can be calculated. 5切 angular difference between points

[0083] Right now:

[0084] The equation for the ellipsoidal surface of the lower head of the conical tank is:

[0085]

[0086] Where (x6, y6, z6) are the coordinates of any point in the coordinate system o6x6y6z6;

[0087] The equation for the generatrix parameter of the ellipsoidal surface of the lower head of the conical tank is as follows:

[0088]

[0089] Where (y6,z6) are the coordinates of any point on the y6o6z6 plane in the coordinate system o6x6y6z6, and φ6 is the angle between the vector on the y6o6z6 plane originating from the origin o6 and the y6 axis. This angle satisfies the generatrix parameter equation of the ellipsoidal surface of the upper head of the conical tank.

[0090] The equation of the geodesic of the ellipsoid of the lower head of the conical tank is:

[0091]

[0092] φ 6切 Let φ6 be the point where the generatrix of the conical surface is tangent to the elliptical generatrix of the lower head of the conical tank. From equation 4 above, the geodesic points φ6 = 0 and φ6 = φ on the lower head ellipsoid can be calculated. 6切 angular difference between points Right now:

[0093]

[0094] The coordinate system o4x4y4z4 takes the conical rotary axis as the z4 axis, takes the conical vertex as the origin, the z4 axis points to the lower end surface of the truncated cone from the origin, and the x4o4y4 plane is perpendicular to the z4 axis; the z5 axis of the coordinate system o5x5y5z5 is opposite to the z4 axis, and the distance between the origin o5 and the origin o4 is z 上+ b 上 sinφ 5切 , the angle between the x5 axis and the x4 axis is This angle is positive when the x4 axis points to the x5 axis counterclockwise around the z5 axis; the z6 axis of the coordinate system o6x6y6z6 is the same as the z4 axis, and the distance between the origin o6 and the origin o4 is z 下+ b 下 sinφ 6切 , the angle between the x6 axis and the x4 axis is This angle is positive when the x4 axis points to the x6 axis counterclockwise around the z5 axis; the above three coordinate systems are right-handed coordinate systems;

[0095] wherein θ4 is the angle between the vector from the coordinate origin to the point (x4, y4) on the x4o4y4 plane and the x4 axis, θ4 is the θ4 of the ellipsoidal surface brachistochrone, θ5 is the angle between the vector from the coordinate origin to the point (x5, y5) on the x5o5y5 plane and the x5 axis, θ5 is the θ5 of the ellipsoidal surface brachistochrone, θ6 is the angle between the vector from the coordinate origin to the point (x6, y6) on the x6o6y6 plane and the x6 axis, θ6 is the θ6 of the ellipsoidal surface brachistochrone, β is the half-conical angle of the conical segment, φ 孔 is the diameter of the circular hole provided on the upper and lower heads, a 上 and b 上 are the long semi-axis length and the short semi-axis length of the ellipsoidal surface of the upper head, respectively, a 下 and b 下 are the long semi-axis length and the short semi-axis length of the ellipsoidal surface of the lower head, respectively, α′ 上 and α′ 下 are the angles between the tangent of the ellipsoidal surface generatrix at the tangent point of the conical generatrix and the ellipsoidal surface brachistochrone and the tangent of the ellipsoidal surface brachistochrone, respectively; k 上 and k 下 are the long-to-short axis ratios of the ellipsoidal surface of the upper head and the ellipsoidal surface of the lower head, respectively;

[0096] The center line of the outer contour surface of one of the equal-pitch double-direction helical ribs is an equal-pitch helix on the ellipsoidal surface of the upper head and an equal-pitch helix on the ellipsoidal surface of the lower head, and is an equal-pitch helix on the conical surface in the conical segment;

[0097] The equation of the equal pitch helix on the conical tank conical surface is:

[0098]

[0099] Substitute z 上 and z 下 into the third equation of the above equation set and subtract, the angle difference between the upper end point and the lower end point of the equal pitch helix on the truncated conical surface can be calculated

[0100]

[0101] In order to make the upper end point of the equal pitch helix on the truncated conical surface coincide with the upper end point of the short line on the truncated conical surface (the starting point of the various helixes at the upper end of the head and the end point of the upper head tangential to the conical section all coincide), rotate counterclockwise around the z4 axis:

[0102]

[0103] The equation of the equal pitch helix on the ellipsoidal surface of the upper head of the conical tank is:

[0104]

[0105] From the fourth equation of the above equation set, the angle difference between φ5=0 and φ5=φ 5切 of the equal pitch helix on the ellipsoidal surface of the upper head can be calculated That is:

[0106] In order to make the equal pitch helix smooth and continuous, rotate counterclockwise around the z5 axis: The equation of the equal pitch helix on the ellipsoidal surface of the lower head of the conical tank is:

[0107]

[0108] From the fourth equation of the above equation set, the angle difference between φ6=0 and φ6=φ 6切 of the equal pitch helix on the ellipsoidal surface of the lower head can be calculated That is:

[0109] In order to make the equal pitch helix smooth and continuous, rotate counterclockwise around the z6 axis:

[0110] Wherein, a 等螺 is the proportionality coefficient of the equal pitch helix on the conical surface, is θ5 of the equal pitch helix on the ellipsoidal surface, is θ6 of the equal pitch helix on the ellipsoidal surface, K 上 and K 下The ratio coefficient of the upper head ellipsoidal surface and the lower head ellipsoidal surface, respectively;

[0111] The outer profile surface center line of one helical rib in the equal helix angle double helical rib is the upper head ellipsoidal surface equal helix angle helix and the lower head ellipsoidal surface equal helix angle helix in the upper head and the lower head, and is the conical surface equal helix angle helix in the cone section;

[0112] The conical surface equal helix angle helix equation is:

[0113]

[0114] The length of the generatrix of the conical surface from the conical vertex to the lower end surface of the truncated cone is ρ 下 Substitute the above equation group 4th formula and subtract, the angle difference between the upper end point and the lower end point of the truncated conical surface equal helix angle helix can be calculated

[0115] That is:

[0116] In order to make the upper end point of the truncated conical surface equal helix angle helix coincide with the upper end point of the truncated conical surface short line (the starting point of the upper head various helixes and the end point of the upper head tangent to the cone section all coincide), rotate counterclockwise around z4 axis:

[0117] The conical storage tank upper head ellipsoidal surface equal helix angle helix equation is:

[0118]

[0119] From the above equation group 4th formula, the angle difference between φ5=0 and φ5=φ 5切 of the upper head ellipsoidal surface equal helix angle helix can be calculated

[0120] That is: In order to make the equal helix angle helix smooth and continuous, the upper head ellipsoidal surface equal helix angle helix rotates counterclockwise around z5 axis:

[0121]

[0122] The conical storage tank lower head ellipsoidal surface equal helix angle helix equation is:

[0123]

[0124] From the above equation group 4th formula, the angle difference between φ6=0 and φ6=φ 6切 of the lower head ellipsoidal surface equal helix angle helix can be calculated

[0125] That is:

[0126] In order to make the equal helix angle helix smooth and continuous, the equal helix angle helix of the upper head ellipsoidal surface is rotated counterclockwise around the z6 axis:

[0127] wherein p is the length of the conic generatrix, is the θ5 of the equal pitch helix of the upper head ellipsoidal surface, is the θ6 of the equal pitch helix of the lower head ellipsoidal surface; φ 锥上 is the upper end diameter of the conical surface, a 锥等螺旋角 is the included angle between the tangent of the conical tank surface generatrix and the tangent of the equal pitch helix of the conical tank surface, k 上 and k 下 are the ratio of the major axis to the minor axis of the upper head ellipsoidal surface and the lower head ellipsoidal surface, respectively.

[0128] hyperbolic cosine inverse function

[0129] hyperbolic tangent inverse function

[0130] Further, the upper end diameter of the conical surface φ 锥上 = 727.602 mm, the lower end diameter of the conical surface φ 锥下 = 950 mm, h = 415 mm, β = 15°, φ 孔 = 280 mm;

[0131] k 上 = 1.60529632, k 下 = 1.60529632, a 上 = 368.8340882 mm, b 上 = 229.7607511 mm, a 下 = 480.4025512 mm, b 下 = 299.9891610 mm, a' 上 = 22.30732623°, a' 下 = 16.90075971°;

[0132] When the start point and the end point of the equal pitch helix of the upper head ellipsoidal surface coincide with the start point and the end point of the short-range line of the upper head ellipsoidal surface, and the start point and the end point of the equal pitch helix of the lower head ellipsoidal surface coincide with the start point and the end point of the short-range line of the lower head ellipsoidal surface, K 上 = 99.74378385;

[0133] When the equal pitch helix of the upper head ellipsoidal surface, the equal pitch helix of the lower head ellipsoidal surface and the equal pitch helix of the conical surface are smooth and continuous, a 等螺距 = 136.6372015, K 下= 130.5270084;

[0134] When the start point and the end point of the upper head ellipsoidal surface equi-spiral angle helix coincide with the start point and the end point of the upper head ellipsoidal surface short-range line, and the start point and the end point of the lower head ellipsoidal surface equi-spiral angle helix coincide with the start point and the end point of the lower head ellipsoidal surface short-range line, α 锥等螺旋角 = 48.01224003°.

[0135] Further, when the middle section is a cone section:

[0136] The skin is automatically laid according to the close-packed helix equation;

[0137] The equation of the close-packed helix of the conical surface is:

[0138]

[0139] The distance z 上 from the vertex of the cone where the conical surface is located to the upper end surface of the truncated cone and the distance z 下 from the vertex of the cone where the conical surface is located to the lower end surface of the truncated cone are substituted into the 4th equation of the above equation set and subtracted to calculate the angle difference between the upper end point and the lower end point of the close-packed helix of the truncated conical surface

[0140] That is:

[0141] In order to make the upper end point of the close-packed helix of the truncated conical surface coincide with the upper end point of the short-range line of the truncated conical surface (it is impossible to make the start point at the polar hole of the close-packed helix of the upper head and the end point at the tangent point of the upper head and the cone section both coincide with the short-range line of the upper head), the z4 axis is counterclockwise rotated by:

[0142]

[0143] The equation of the close-packed helix of the conical head ellipsoidal surface of the conical storage tank is:

[0144]

[0145] φ 0上 is the φ5 when the included angle between the tangent of the generatrix of the conical head ellipsoidal surface and the tangent of the close-packed helix of the conical head ellipsoidal surface is 0; the angle difference between the φ5=0 point and the φ5=φ 5切 point of the close-packed helix of the conical head ellipsoidal surface can be calculated from the 4th equation of the above equation set

[0146] That is:

[0147] In order to make the close-packed helix smooth and continuous, the close-packed helix of the conical head ellipsoidal surface is counterclockwise rotated around the z5 axis by:

[0148]

[0149] The equation of the close-packed helical line of the ellipsoid surface of the lower head of the conical tank is:

[0150]

[0151] φ 0下 is φ6 when the included angle between the tangent of the generatrix of the ellipsoid surface of the lower head and the tangent of the close-packed helical line of the ellipsoid surface of the lower head is 0. The angle difference between φ6=0 and φ6=φ6 of the close-packed helical line of the ellipsoid surface of the lower head can be calculated according to the fourth equation in the above equation group. 6切

[0152] That is:

[0153] In order to make the close-packed helical line smooth and continuous, the close-packed helical line of the ellipsoid surface of the lower head is counterclockwise rotated around z6 axis:

[0154] Further, when the cylindrical tank with the middle section being a column section is formed, the cylindrical tank is divided into two parts by the middle of the middle section, and the two parts are formed respectively.

[0155] Let the skin thickness be t, first form the bidirectional helical rib of the two parts and the skin with a thickness of t / 3, and additionally form a thickened area at the joint of the two parts. After curing, process a sunken area that cooperates with each other at the thickened area of the two parts. After the two parts are inserted through the sunken area, form the skin with a remaining thickness of 2t / 3, and perform secondary curing to obtain the cylindrical tank.

[0156] When the conical tank with the middle section being a cone section is formed, the conical tank is divided into a first part and a second part by the maximum diameter of the conical tank, and the first part and the second part are formed respectively. The first part includes: the upper head and the lower head with a smaller diameter, the cone section, and a part of the upper head and the lower head with a larger diameter. The second part includes: another part of the upper head and the lower head with a larger diameter.

[0157] When the conical tank is formed, a transition section is additionally processed on the first part and the second part. The first part and the second part are inserted by using the transition section to obtain the conical tank.

[0158] The transition section is a column section, and the bidirectional helical rib of the transition section is formed according to the transition section column surface short-range line equation.

[0159]

[0160] Wherein α 柱过渡 is the included angle between the tangent of the generatrix of the transition section column surface and the tangent of the helical line of the transition section column surface. ​

[0161] When the transition section cylinder asper is smoothly continuous with the conical tank asper, α 柱过渡 = 16.7050855°, the transition section angle is 4.5°, and the transition section length is 125.7225224 mm.

[0162] Further, the arc length of the helix on the ellipsoid asper of the upper head and the lower head is determined according to the following formula:

[0163] The arc length of the short-range helix on the ellipsoid asper of the tank is:

[0164]

[0165] The arc length of the equal-pitch helix on the ellipsoid asper of the cylindrical tank with a cylinder section in the middle section is:

[0166]

[0167] The arc length of the equal-helix-angle helix on the ellipsoid asper of the cylindrical tank with a cylinder section in the middle section is:

[0168]

[0169] The arc length calculation of the densely packed helix on the ellipsoid asper of the tank is:

[0170]

[0171] wherein γ is the included angle between the tangent of the ellipsoid asper generatrix and the Z-axis, α is the included angle between the tangent of the ellipsoid asper generatrix and the helix tangent, φ is the parameter of the elliptic parameter equation on the yoz plane, (y, z) is the coordinates of any point on the ellipsoid asper generatrix in the coordinate system oxyz, φ0 is the φ when the included angle between the tangent of the ellipsoid asper generatrix and the tangent of the densely packed helix of the ellipsoid asper is 0; φ 起点 is the φ at the starting point of the sought ellipsoid asper helix; φ 终点 is the φ at the end point of the sought ellipsoid asper helix; and b is the minor axis length of the ellipsoid asper. The coordinate system oxyz takes the tank ellipsoid asper rotation axis as the z-axis, takes the intersection of the z-axis and the ellipsoid lower end face as the origin, and takes the z-axis pointing to the ellipsoid top end from the origin, with the xoy plane being perpendicular to the z-axis.

[0172] Further, the tank is connected with the external forked ring, and the connection form of the tank and the external forked ring is:

[0173] The cylinder section of the tank is processed into an arc-shaped depression, the aluminum alloy ring-shaped part is processed into an arc-shaped convex chord matching the arc-shaped depression, the aluminum alloy ring-shaped part is glued with the cylinder section, the convex chord of the aluminum alloy ring-shaped part and the depression of the cylinder section are clamped with each other, and a composite material is wound at the connection between the aluminum alloy ring-shaped part and the cylinder section and is solidified.

[0174] The forming tool of the automatic forming composite material oblique grid storage tank comprises a three-dimensional pouring forming tank head silicone rubber grid mold;

[0175] When the three-dimensional pouring forming tank head silicone rubber grid mold is formed, the silicone rubber male mold is used as the mold;

[0176] A suitable tangent plane is selected, so that the distance between the four corners of the tank head silicone rubber grid mold and the tangent plane is equal, and the pouring port is arranged on the side of the silicone rubber male mold without a grid rib groove;

[0177] The calculation method of the normal direction of each point on the helix of the tank head silicone rubber grid mold is as follows:

[0178] The unit normal vector of the curved surface is:

[0179]

[0180] Wherein E, F and G are the first basic quantities:

[0181] F=r φ ·r θ 、

[0182] r=|g (phi) cos theta, g (phi) sin theta, f (phi)|

[0183] r=|acos phi cos theta, acos phi sin theta, b sin phi|

[0184] Thus, the normal direction of each point on the short-range line of the ellipsoid surface is obtained, which is used to ensure that the helical rib of the tank head silicone rubber grid male mold is along the normal direction. When phi=phi1 and theta=theta1, the normal direction of each point on the short-range line of the ellipsoid surface of the upper head of the cylindrical storage tank is obtained. In the same way, the normal direction of each point on the short-range line of the ellipsoid surface of the lower head of the cylindrical storage tank and the normal direction of each point on the short-range line of the ellipsoid surface of the upper and lower heads of the conical storage tank can be obtained.

[0185] Compared with the prior art, the present application has at least one of the following beneficial effects:

[0186] (1) The composite material grid storage tank of the present application is an oblique grid structure, which improves the structural rigidity by increasing the grid reinforcing ribs, reduces the deformation of the composite material grid storage tank when bearing a large internal pressure, and thus solves the problem of low-temperature medium sealing; at the same time, the structural bearing efficiency is improved by increasing the grid reinforcing ribs.

[0187] (2) The center line of the grid reinforcing rib of the composite material storage tank is a brachistochrone on the ellipsoid head surface and the cylindrical surface, the winding track of the grid reinforcing rib is accurately calculated, the ellipsoid head of the composite material grid storage tank is utilized to realize the automatic continuous winding of the reinforcing rib and the skin, the manhole can play the role of the torus, and the product is suitable for batch production.

[0188] (3) The center line of the grid reinforcing rib of the composite material storage tank can also be designed as a helix with equal pitch or a helix with equal helix angle on the ellipsoid head surface and the cylindrical surface according to requirements, the track of the grid reinforcing rib can also be accurately calculated to realize automatic laying, and the product is also suitable for batch production.

[0189] (4) The ellipsoid surface is a non-developable complex surface, the helix with equal pitch or the helix with equal helix angle on the ellipsoid surface is a complex spatial curve, and the silicon rubber grid male die formed by the complex spatial curve has double curvature, good adhesion with the ellipsoid surface of the core die and good continuity of the helical rib groove.

[0190] (5) The silicon rubber grid male die is formed by stereoscopic pouring, each silicon rubber grid male die is only one fifth to one eighth of the circumference, the grid processing amount is greatly reduced, the five-coordinate machine tool processing time can be greatly reduced, the processing cost can be reduced, the processing period can be compressed, and the product quality is not affected, so that the cost is reduced and the development progress is accelerated.

[0191] (6) The geometric size of the silicon rubber grid male die is not as accurate as that of the hard die, but the use requirements can be met under the condition of greatly reducing the cost.

[0192] (7) The composite material grid storage tank skin is formed in an automatic laying and winding manner, the shear capacity of the reinforced skin and the rib interface can be improved, the outer layer wrinkle of the skin can be reduced, the laying angle of the tank head can be optimized, and the thickness of the tank head can be gradually changed.

[0193] (8) The composite material grid storage tank is divided into two halves in the middle of the column segment, is formed respectively, a thickening area with the same height as the rib is formed at the joint, the structure is solidified, and a sunken area that cooperates with each other is processed in the thickening area and is inserted together, the circumferential stress of the storage tank is twice the axial stress, the inserted part plays the role of a ring rib, and the load bearing capacity of the structure is improved.

[0194] (9) The composite material grid storage tank meets the productization requirements, the conical tank which is difficult to be formed by a metal tank is designed as a composite material grid tank and can be automatically formed, is suitable for designing and forming the oxidizer tank and the combustion agent tank of each stage of the liquid rocket, has good structural integrity, good forming process, high production efficiency, realizes low cost and light weight, and can quickly form the composite material grid storage tank. BRIEF DESCRIPTION OF DRAWINGS

[0195] Figure 1Automatic forming composite grid tank three-dimensional model provided by the present application; wherein (a) is a three-dimensional model, (b) is a sectional view;

[0196] Figure 2 Helical line on the surface of revolution of the present application;

[0197] Figure 3 Cylindrical tank short-range helical line inclined grid of the present application;

[0198] Figure 4 First winding fiber tow trajectory of the cylindrical tank of the present application;

[0199] Figure 5 Composite grid tank one-time winding three-dimensional model sectional view of the present application;

[0200] Figure 6 Composite grid tank one-time winding three-dimensional model of the present application;

[0201] Figure 7 Composite grid tank one-time curing three-dimensional model sectional view of the present application (the negative mold is not shown);

[0202] Figure 8 Composite grid tank one-time curing three-dimensional model of the present application;

[0203] Figure 9 Composite grid tank secondary winding three-dimensional model sectional view of the present application;

[0204] Figure 10 Composite grid tank secondary winding three-dimensional model of the present application;

[0205] Figure 11 Composite grid tank secondary curing three-dimensional model sectional view of the present application; wherein (a) is a three-dimensional model, (b) is a sectional view;

[0206] Figure 12 Composite grid tank secondary curing three-dimensional model of the present application;

[0207] Figure 13 Composite grid tank head silicone grid male mold three-dimensional model of the present application;

[0208] Figure 14 Head silicone grid male mold solid casting mold of the present application; wherein, (a) is a front view, (b) is a sectional view of B-B direction of figure (a), (c) is a sectional view of A-A direction of figure (a);

[0209] Figure 15 Head silicone grid male mold solid casting mold lower mold three-dimensional model of the present application;

[0210] Figure 16Normal direction on the brachistochrone of the ellipsoidal head of the storage tank of the application

[0211] Figure 17 Three-dimensional model of the silicon rubber grid male die for the composite material grid storage tank column section of the application

[0212] Figure 18 Stereocasting mold of the silicon rubber grid male die for the column section of the application; wherein the lower left is the front view, the upper left is the A-A direction sectional view of the front view, and the upper right (i.e. figure (c)) is the B-B direction sectional view of the A-A direction sectional view;

[0213] Figure 19 Three-dimensional model of the lower mold of the stereocasting mold of the silicon rubber grid male die for the column section of the application

[0214] Figure 20 Oblique grid of the equal-pitch helix of the cylindrical storage tank of the application

[0215] Figure 21 Oblique grid of the equal-helix-angle helix of the cylindrical storage tank of the application

[0216] Figure 22 Close-packed helix of the cylindrical storage tank of the application

[0217] Figure 23 Comparison of the three kinds of helixes of the cylindrical storage tank of the application

[0218] Figure 24 Oblique grid of the brachistochrone of the conical storage tank of the application

[0219] Figure 25 First winding fiber tow trajectory of the conical storage tank of the application

[0220] Figure 26 Connection form at the butt joint of the conical storage tank of the application

[0221] Figure 27 Oblique grid of the equal-pitch helix of the conical storage tank of the application

[0222] Figure 28 Oblique grid of the equal-helix-angle helix of the conical storage tank of the application

[0223] Figure 29 Oblique grid of the close-packed helix of the conical storage tank of the application

[0224] Figure 30 Comparison of the three kinds of helixes of the conical storage tank of the application

[0225] Figure 31 Sectional view at the forked ring of the application

[0226] Figure 32 Unfolding diagram of the outer surface of the ring-shaped member at the forked ring of the application

[0227] In the figure: 1 - mandrel, 2 - spherical silicone rubber grid mold, 3 - cylindrical silicone rubber grid mold, 4 - core mold, 5 - flange, 6 - metal ring, 7 - adapter plate, 8 - steel belt, 9 - bent plate, 10 - nut, 11 - bolt, 12 - positioning shaft, 13 - female mold, 14 - middle mold one, 15 - middle mold two, 16 - middle mold three, 17 - grid bottom mold, 18 - top cover, 19 - lifting ring, 20 - nut, 21 - positioning pin, 22 - limiting pin, 23 - middle mold four. DETAILED DESCRIPTION

[0228] The features and advantages of the present application will become more apparent from the detailed description in conjunction with the accompanying drawings.

[0229] The term "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations. Unless specifically stated otherwise, the drawings are not drawn to scale and the appended description is not intended to be limiting.

[0230] The present application provides a composite grid tank and a forming tool thereof. The composite grid tank is designed reasonably, effectively seals low-temperature medium, and realizes low cost and lightweight. The composite grid tank and the forming tool thereof have low manufacturing cost and are suitable for automatic batch production of the composite grid tank.

[0231] In the present application:

[0232] The cylindrical composite grid tank is a diagonal grid structure, and the center line of the grid reinforcing rib is an equal-pitch helix on the ellipsoidal head surface and the cylindrical surface, an equal-helix-angle helix, or a geodesic.

[0233] The forming tool of the cylindrical composite grid tank, and the grid male die is a silicone rubber grid male die, which is formed by stereoscopic pouring.

[0234] The forming tool of the cylindrical composite grid tank, and the helical rib on the lower die of the ellipsoidal head silicone rubber grid male die is in the normal direction of the ellipsoidal head surface, and the normal direction is accurately calculated.

[0235] The cylindrical composite grid tank is finally formed through two winding and two curing.

[0236] The trajectories of the grid reinforcing ribs of the cylindrical composite tank are accurately calculated. The equal-pitch helical rib and the equal-helix-angle helical rib grid structure are automatically formed by automatic laying of the grid reinforcing ribs, and the geodesic helical rib grid structure is automatically formed by automatic winding of the grid reinforcing ribs, realizing continuous automatic winding.

[0237] The cylindrical composite material grid tank skin is automatically laid and wound, the inner layer skin is continuously and automatically wound to form the skin and the rib, so that the skin and the rib are closely combined and the interface shear capacity between the skin and the rib is enhanced; the outer layer skin is continuously and automatically wound to maintain a certain tension by using the outer layer skin, and the outer layer skin is reduced; the remaining layers of the skin can be automatically laid along the equal pitch, equal spiral angle, densely arranged spiral lines according to the needs, so that the laying angle of the tank head is optimized and the thickness gradually changes.

[0238] The cylindrical composite material grid tank is precisely calculated in terms of the arc length of the ellipsoid head profile pitch spiral line, the equal spiral angle spiral line, the short-range line and the densely arranged spiral line, so that the automatic laying, automatic winding and automatic cutting of the fiber tows are realized.

[0239] The conical composite material grid tank is a grid structure, and the center line of the grid rib is an equal pitch spiral line or an equal spiral angle spiral line on the ellipsoid head profile and the conical surface. The conical composite material grid tank is more difficult to design and form than the cylindrical composite material grid tank, but the design and formation thereof can refer to the cylindrical composite material grid tank.

[0240] The trajectory of the conical composite material tank grid rib is precisely calculated. The equal pitch spiral rib and the equal spiral angle spiral rib grid structure is automatically formed by automatic laying; the short-range line spiral rib grid structure is automatically formed by automatic winding, and continuous automatic winding is realized.

[0241] The conical composite material tank grid skin is automatically laid and wound, the inner layer skin is continuously and automatically wound to form the skin and the rib, so that the skin and the rib are closely combined and the interface shear capacity between the skin and the rib is enhanced; the outer layer skin is continuously and automatically wound to maintain a certain tension by using the outer layer skin, and the outer layer skin is reduced; the remaining layers of the skin can be automatically laid along the equal pitch, equal spiral angle, densely arranged spiral lines according to the needs, so that the laying angle of the tank head is optimized and the thickness gradually changes.

[0242] The structure of the application has the advantages of reasonable design, effective realization of low-temperature medium sealing, low cost, lightweight, etc., and the manufacturing tooling of the structure has the advantages of low manufacturing cost and suitability for automatic batch production of the structure.

[0243] Embodiment:

[0244] This embodiment is combined with the accompanying drawings Figures 1-32 for detailed description.

[0245] 1) Composition and size of the cylindrical tank

[0246] Taking the center of the ellipse as the coordinate origin, taking the y1 axis as the horizontal coordinate and the z1 axis as the vertical coordinate, the ellipse generatrix equation of the two end heads of the cylindrical tank is:

[0247]

[0248] where: a = 400, b = 250, a = kb, k = 1.6

[0249] The cylinder section is a 408 mm long cylinder. There is a φ250 mm hole in each end head.

[0250] The center line of the rib constituting the inclined grid is a spiral line on the surface of the tank. The composite tank skin is also automatically wound or automatically laid on the spiral line on the surface of the tank.

[0251] 2) Spiral angle calculation of spiral line on curved generatrix revolving surface

[0252] As shown in Figure 2 , the spiral angle α of the spiral line is defined as the included angle between the tangent of the generatrix and the tangent of the spiral line. Take any point A(x, y, z) on the spiral line, polar coordinates A(r, θ, z). Let the parameter equation of the generatrix be:

[0253]

[0254] The tangent of the generatrix is:

[0255]

[0256] Form a revolving surface with the z-axis as the axis of revolution.

[0257] The direction vector of the tangent of the generatrix at point A is:

[0258]

[0259] Let the parameter equation of the spiral line be:

[0260]

[0261] The direction vector of the tangent of the spiral line at point A is:

[0262]

[0263] The spiral angle α at point A satisfies the following relationship:

[0264]

[0265]

[0266]

[0267]

[0268] Because of the symmetry of the helix on the surface of revolution, only the positive sign is taken in the above equation.

[0269] 3) Geodesic on the ellipsoidal surface of the head of the cylindrical tank

[0270] The helix on the surface of revolution that satisfies the Clairant theorem is a geodesic.

[0271] r1 sin α1 = r2 sin α2 = r s in 90° = const (10)

[0272] In the equation, r1 is the radius of the first point on the generatrix, α1 is the winding angle of the first point, r2 is the radius of the second point on the generatrix, α2 is the winding angle of the second point, and r = const is the polar hole radius of the geodesic helical winding pattern.

[0273] As can be seen from equation (8),

[0274]

[0275] Multiply both sides by R2 = g 2 (t) (equation (2))

[0276]

[0277] The solution is:

[0278]

[0279]

[0280] 3.1) Ellipsoidal geodesic

[0281] Taking the φ250mm circular hole at both ends of the head as the polar hole, we have from equation (10):

[0282] 400 sin α 短程线 = 125 sin 90° = C (15)

[0283] The solution is: 短程线 = 18.20995686° (16)

[0284] sin α 短程线 = 0.3125

[0285] Substituting the elliptical generatrix equations (1) and (15) into equation (14), we have:

[0286]

[0287] From equations (1), (5), and (17), the equation of the ellipsoidal geodesic on the head of the cylindrical tank that needs to be designed in this paper is:

[0288]

[0289] To make the spiral line on the ellipsoid with the same end point, the short-range line on the ellipsoid is calculated between the end points of the short-range line

[0290] The upper limit of integration is α 短程线 The angles are complementary.

[0291] 3.2) Short-range line of the cylinder

[0292] Cylinder: The formula (20) is brought into the following formula (14):

[0293]

[0294]

[0295] z2=R cot α 短程线 (θ2-C) (23)

[0296] C=0 can be taken, and the short-range line of the cylinder is:

[0297]

[0298] To make the short-range line on the tank smooth and continuous, the equation of the short-range line of the cylinder of the tank designed in this paper is:

[0299]

[0300] The oblique grid of the short-range spiral line of the cylindrical tank is shown in Figure 3

[0301] 4) Forming of the oblique grid tank of the short-range line of the composite material of the cylinder

[0302] 4.1) Winding and curing of the oblique grid tank of the short-range line of the composite material of the cylinder

[0303] The spacing between the oblique ribs is 10°, the height of the rib is 8mm, the width of the rib is 5mm, and the thickness of the skin is 3mm. To facilitate demolding, the tank is divided into two halves in the middle of the cylinder segment and formed respectively. During the forming, the forming rib and the 1mm thick skin are wound first, and the butt joint is formed with the thickening area with the same height as the rib. The structure is cured. The recessed areas that cooperate with each other are processed in the thickening area and inserted together. Then the remaining 2mm thick skin is wound and formed, and finally the second curing is carried out. Since the winding trajectory can be accurately calculated, the butt joint winding of the two parts can be realized. In this way, the material is not wasted, and the automatic rapid forming is easy. The hoop stress of the tank cylinder segment is twice the axial stress, and the butt joint is reinforced in the hoop direction. For example Figure 1 ​The rest of the grid form of the storage tank is only different in the grid form, while the cross section of the rib and the thickness of the skin are the same, so only the grid form is shown. The spiral line on the surface of revolution is shown as Figure 2 . .

[0304] The fiber tows of the first winding of the cylindrical storage tank are wound along the trajectory, and the column segment is extended by 5° on the basis Figure 3 , which is used for forming the butt joint thickening area, as shown in Figure 4 . .

[0305] The mold winding state is mainly composed of the following parts: mandrel, core mold, silicone rubber split male mold, flange, stop ring, key, small key, etc. The 66mm silicone rubber split male mold area in the middle is filled with a 66mm wide and 10mm thick silicone rubber plate.

[0306] The mold curing state is mainly composed of the following parts: core mold, silicone rubber split male mold, flange, outer mold.

[0307] The twice winding and twice curing of the composite material grid storage tank are shown in Figures 5-12 , in which: 1-mandrel, 2-spherical silicone rubber grid mold, 3-column segment silicone rubber grid mold, 4-core mold, 5-flange. 6-metal ring, 7-adapter disc, 8-steel belt, 9-bending plate, 10-nut, 11-bolt, 12-positioning shaft, 13-female mold, 14-middle mold one, 15-middle mold two, 16-middle mold three, 17-grid bottom mold, 18-top cover, 19-lifting ring, 20-nut, 21-positioning pin, 22-limiting pin, 23-middle mold four.

[0308] 4.2) Pouring forming of the silicone rubber grid mold of the storage tank head

[0309] Since the head is an ellipsoid, its surface is a non-developable surface, so the forming of the silicone rubber grid mold of the storage tank head is difficult, and needs to be completed in the form of three-dimensional pouring. Choose the right tangent plane, so that the four corners of the silicone rubber grid mold of the storage tank head are at a distance of about equal to the tangent plane, try to make the three-dimensional pouring planar, fully utilize the smooth flow of the arc surface to ensure the pouring quality of the silicone rubber male mold. The pouring port is set on the side of the silicone rubber male mold without grid rib grooves, to ensure the pouring quality of the grid rib grooves, and thus ensure the quality of the grid ribs of the composite material grid structure. See Figure 13 . Figure 15 .

[0310] 4.3) Calculation of the normal direction of the spiral line on the ellipsoid surface

[0311] Unit normal vector of the surface:

[0312]

[0313]

[0314] where E, F, G are the first basic quantities:

[0315]

[0316]

[0317] r = |g(φ)cosθ, g(φ)sinθ, f(φ) (29)

[0318] r = |acosφcosθ, acosφsinθ, bsinφ (30)

[0319] Thus the normal direction of each point on the short-range line of the ellipsoidal surface is obtained, which is used to ensure the helical rib of the grid male die of the silicone rubber along the normal direction. The normal direction of each point on the short-range line of the ellipsoidal surface of the upper head of the cylindrical storage tank is shown in Fig. 6. Figure 16 When φ = φ1, θ = θ1, the normal direction of each point on the short-range line of the ellipsoidal surface of the upper head of the cylindrical storage tank is obtained. In the same way, the normal direction of each point on the short-range line of the ellipsoidal surface of the lower head of the cylindrical storage tank and the normal direction of each point on the short-range line of the ellipsoidal surface of the upper and lower heads of the conical storage tank can be obtained.

[0320] 4.4) Casting of the silicone rubber grid die of the cylindrical section of the storage tank

[0321] The casting of the silicone rubber grid die of the cylindrical section of the storage tank is shown in Fig. 7. Figure 17 Figure 19 .

[0322] 5) Helical lines with equal pitch on the surface of the cylindrical storage tank

[0323] In formula (5), when z is in linear ratio with θ, the helical line on the surface of the revolution is the helical line with equal pitch.

[0324] 5.1) Helical lines with equal pitch on the ellipsoidal surface

[0325] Let θ1= k 柱等螺距 sinφ1 (31)

[0326] Combined with formula (19), the distance between the two end points of the helical line with equal pitch on the ellipsoidal surface is calculated. and let it be equal to

[0327]

[0328] k 柱等螺距 = 87.20389426 (33)

[0329] From formula (1), (5), (31) and (33), the equation of the helical line with equal pitch on the ellipsoidal surface of the storage tank designed in this paper is:

[0330] ​​

[0331] Note that formula (33) is in degrees, which should be converted to radians when substituted into formula (9).

[0332]

[0333] When φ1=0°,

[0334]

[0335] Solving for α 等螺距 = 67.67472979° (37)

[0336] 5.2) Cylindrical equal pitch helix

[0337] The cylindrical equal pitch helix in formula (5) is:

[0338]

[0339] Substitute formula (38) into formula (9):

[0340]

[0341] k0 is a constant.

[0342] k0 = R cot α 等螺距 (40)

[0343] The cylindrical equal pitch helix is:

[0344]

[0345] In order to make the equal pitch helix on the tank smooth and continuous, from formula (37), the cylindrical equal pitch helix equation of the tank designed in this paper is:

[0346]

[0347] The oblique grid of the cylindrical tank equal pitch helix is shown in Figure 20 .

[0348] 6) Equal helix angle helix on the surface of the cylindrical tank

[0349] In formula (9), when α is a constant, the helix on the surface of revolution is an equal helix angle helix.

[0350] 6.1) Ellipsoidal equal helix angle helix

[0351] Substitute formula (1) into formula (9):

[0352]

[0353]

[0354] Combining equation (19), the equal helix angle helix between the two endpoints of the ellipsoid surface is calculated And let it be equal to

[0355]

[0356] Solving tanα 等螺旋角 = 0.965 (46)

[0357] That is, α 等螺旋角 = 43.97957239° (47)

[0358]

[0359] 6.2) Cylindrical surface equal helix angle helix

[0360] Cylindrical surface parameter equation:

[0361]

[0362] Bring equation (49) into equation (9):

[0363]

[0364] z2= R cotα 等螺旋角 (θ2-c) (51)

[0365] You can take C = 0

[0366] Cylindrical segment equal pitch helix is:

[0367]

[0368] In order to make the equal helix angle helix on the tank smooth and continuous, from equation (47), the cylindrical surface equal helix angle helix equation of the tank designed in this paper is:

[0369]

[0370] The oblique grid of cylindrical tank equal helix angle helix is shown in Figure 21 .

[0371] 7) Dense spiral on the surface of cylindrical tank

[0372] Suppose the width of the fiber tows is d, and there are n fiber tows. The circumference at R0 is: 2πR0 = nd, and the circumference at R is: 2πR = nd R .

[0373] In order to make the fiber tow centerline automatically lay along the dense spiral, then:​

[0374] d = d R cosα 密排 (54)

[0375] R0 = R cosα 密排 (55)

[0376]

[0377] R0: R when α = 0.

[0378] 7.1) Ellipsoidal close-packed helix

[0379] From equation (56):

[0380] Substitute equation (43) into equation (56):

[0381]

[0382]

[0383] The value range of φ0 is 71.79004314°-90°. When φ0 = 71.79004314°, i.e. 1.252972623 rad:

[0384]

[0385] Therefore, the close-packed helix cannot pass through the same two endpoints as the other three helices.

[0386] Let: φ0 = 71.79004314°,

[0387] The equation of the close-packed helix on the ellipsoid is:

[0388]

[0389] 7.2) Cylindrical close-packed helix

[0390] Since the cylinder segment R0 = R, equation (57) is an identity.

[0391] The development of helices with the same helix angle on the cylinder is parallel lines, proving that the helix on the cylinder is a close-packed line.

[0392] From equation (56):

[0393] cosα 密排 = R0 / R = cosφ0 / cosφ1 (62)

[0394] Since φ1 = 0 and cosφ1 = 1 at the intersection of the cylinder and the ellipsoid, α 密排 = φ0.

[0395] Equation of the spiral line of the cylindrical section of the tank:

[0396]

[0397] The close-packed spiral line is used for the laying of the equal-thickness skin.

[0398] In order to make the close-packed spiral line on the tank smooth and continuous, the equation of the close-packed spiral line of the cylindrical section of the tank designed in this paper is:

[0399]

[0400] The four spiral lines of the cylindrical section of the tank are the same kind of spiral line according to equation (24), equation (41), equation (52) and equation (63).

[0401] The close-packed spiral line of the cylindrical tank is shown in Figure 22 .

[0402] The comparison of the three spiral lines of the cylindrical tank is shown in Figure 23 .

[0403] Since the diameter of the ellipsoidal end of the tank gradually decreases from the connection of the cylindrical section, the fiber tows need to be reduced during the automatic winding and automatic laying process. The reduction laying is related to the diameter of the structure and the cosine of the spiral angle of the fiber tows, and the relationship between the three is expressed by equation (54). The equal-spiral-angle spiral line is only related to the diameter. The diameter of the close-packed line and the cosine of the spiral angle of the fiber tows just offset each other. The cosine of the included angle of the equal-pitch spiral line needs to be calculated by equation (35). And the short-range line appears the situation of d / cos90=d / 0 at the polar hole, so the structure at the polar hole position will be very thick, and needs to be automatically reduced. The reduction forming should be related to the arc length of the spiral line to realize the automatic cutting of the fiber tows according to the requirements.

[0404] 8) The structure and size of the conical tank

[0405] Taking the center of the ellipse as the coordinate origin, and taking the y5 axis as the horizontal coordinate and the z5 axis as the vertical coordinate, the equation of the elliptical generatrix of the conical tank end cover is:

[0406]

[0407] The ratio of the major axis to the minor axis of the elliptical end cover is about 1.6.

[0408] The upper end diameter of the conical section of the conical composite inclined grid tank is 727.602 mm, the lower end diameter is 950 mm, the height is 415 mm, and the half-cone angle β of the conical section is 15°. There is a φ280 mm circular hole in each of the upper and lower end covers, and the spiral rib spacing on the conical surface is 9°. The upper and lower ends of the cylindrical section are tangent to the upper ellipsoidal end cover and the lower ellipsoidal end cover, respectively. Taking this structure as an example, the design of the conical composite inclined grid tank is carried out.

[0409] The center line of the stringers that make up the oblique grid is a spiral on the conical tank face. The composite tank skin that is wound into shape is also automatically wound or automatically laid in a spiral on the tank face.

[0410] 9) brachistochrone on the conical tank face

[0411] 9.1) brachistochrone on the conical face

[0412] Brachistochrone on the conical cylindrical face:

[0413]

[0414] Bring formula (66) into formula (14):

[0415] Yield:

[0416] That is:

[0417] Integrate to get:

[0418]

[0419] That is:

[0420] For the conical tank studied in this paper, the third formula of formula (66) is:

[0421]

[0422] The brachistochrone equation of the conical section is:

[0423]

[0424]

[0425] Let the central angle of the bidirectional spiral stringer at the lower end of the conical section be 3.85265°.

[0426] Central angle of bidirectional spiral stringer at upper end of conical section:

[0427] 5×9°-3.85265°-2×21.2162159°=-1.2850818°

[0428] 9.2) brachistochrone on the upper head ellipsoidal face

[0429] a 上 =k 上 b 上 (71)

[0430]

[0431] Radius of upper end of cone section

[0432]

[0433] c = a 上 sin α' 上 = 140 (74)

[0434]

[0435] φ 5终 = 90° - α' 上 (76)

[0436]

[0437]

[0438] Solving the equations (71) - (78), the values of the parameters are as follows:

[0439] Table 1

[0440]

[0441] b 上 sin φ 5切 = 37.82735011, the distance from the apex of the cone to the upper end of the truncated cone: z 上 = 1357.724134, the distance from the center of the ellipsoid to the apex of the cone: 1395.551166.

[0442] The equation of the geodesic of the ellipsoid for the upper head:

[0443]

[0444] where:

[0445] 9.3) The geodesic of the ellipsoid for the lower head

[0446] Still using the eight equations (71) - (78) to solve the structural parameters, but the specific forms and values of the equations are changed:

[0447] Radius of lower end of cone section:

[0448]

[0449] Radius of upper end of cone section

[0450]

[0451] c = a 下 sin α' 下 = 140 (74')

[0452]

[0453] φ 6终 = 90° - α' 下 (76')

[0454]

[0455]

[0456] The values of the parameters obtained by solving the equations are shown in the following table:

[0457] Table 2

[0458]

[0459] b 下 sinφ 6切 = 49.38961493, the distance from the cone top to the lower end surface of the truncated cone: z 下 = 1772.724134, the distance from the ellipsoid center to the cone top is the sum of the above two: 1822.113749.

[0460] The short-range line equation of the ellipsoid is:

[0461]

[0462] Wherein:

[0463] The short-range line inclined grid of the conical storage tank is shown in Figure 24 .

[0464] The conical composite material grid storage tank should be divided at the maximum diameter, that is, the small head and the conical section and a small part of the large head are integrally formed, and the vast majority of the large head is separately formed. Otherwise, it is difficult to demold.

[0465] According to the principle of Clery:

[0466] The value of α is obtained by solving the equation 柱过渡 = 16.7050855°.

[0467] The short-range line equation of the transition cylindrical surface is:

[0468]

[0469] The transition angle is 4.5°, and the transition length is 125.7225224 mm.

[0470] 18x9°+17x9°+9°+3.85265°-1.2850818°+21.2162159°x2=369°, 369°-360°=9°, can be continuous winding. The first winding fiber track of the conical storage tank is shown in Figure 25 .

[0471] The connecting form of the conical storage tank butt joint is shown in Figure 26 ;

[0472] 10) Equal pitch helix on the surface of conical storage tank

[0473] 10.1) Equal pitch helix on the ellipsoidal surface of upper head

[0474] Let

[0475] Combined with the value of φ 5切 , φ 5终 , in Table 1,

[0476]

[0477] Solving K 上 = 99.74378385

[0478] The equation of equal pitch helix on the ellipsoidal surface of upper head of the storage tank to be designed in this paper is:

[0479]

[0480] Note that K 上 is obtained in angle system, which should be converted to radian system when substituted into equation (9).

[0481]

[0482] Substitute φ 5切 into equation (85) to solve the angle α 上 between the tangent of ellipsoidal generatrix at the tangent point of conical section and upper head and the tangent of equal pitch helix of ellipsoid, which is:

[0483] 10.2) Equal pitch helix on the conical surface

[0484] Let the equation of equal pitch helix on the conical surface be:

[0485]

[0486] Substitute equation (86) into equation (9):

[0487]

[0488] k1 is a constant,

[0489] Let k1 = a cos β (88)

[0490] At the tangent point of the conical section and the upper head,

[0491] tan α 锥等螺距 = tan α 上 = θ 上 sin 15° (89)

[0492] Solving θ 上 = 10.28723832 rad.

[0493] The conical surface equal-pitch helix is:

[0494]

[0495] From the third equation of formula (90), we have: 上 = a · θ 上 · cos 15°

[0496] Solving a = 136.6372015, and substituting this value and β = 15° into formula (90), we obtain the equation of the equal-pitch helix of the conical section of the storage tank designed in this paper.

[0497] Similarly, we have: 下 = a · θ 下 · cos 15°

[0498] Solving θ 下 = 13.43162074 rad.

[0499] 10.3) Lower head ellipsoidal surface equal-pitch helix

[0500] At the tangent point of the conical section and the lower head,

[0501] tan α 下 = θ 下 · sin 15° (91)

[0502] Solving the angle α between the ellipsoidal generatrix tangent and the ellipsoidal equal-pitch helix tangent at the tangent point of the conical section and the lower head, 下 = 73.95173427° From formula (9):

[0503]

[0504] Substituting φ 6切 into formula (92), we obtain: 下 = 130.5270084

[0505] The equation of the lower head ellipsoidal surface equal-pitch helix of the storage tank designed in this paper is:

[0506]

[0507] Conical tank Equi-pitch helixes Oblique grid Figure 27 .

[0508] 11) Conical tank Equi-helix angle helixes

[0509] 11.1) Upper head ellipsoidal surface Equi-helix angle helixes

[0510] Substitute equation (65) into equation (9),

[0511]

[0512] Integrating, we have

[0513]

[0514] where

[0515] Δθ5= θ 锥 (φ 5终 )-θ 锥 (φ 5切 ) (97)

[0516] Solving, we have tanα 锥等螺旋角 = 1.11108976 (98)

[0517] That is, α 锥等螺旋角 = 48.01224003° (99)

[0518] 11.2) Conical surface Equi-helix angle helixes

[0519] Conical surface parameter equation:

[0520]

[0521] Substitute equation (100) into equation (9),

[0522]

[0523] That is,

[0524] Integrating, we have

[0525] Thus, the solution of the differential equation is:

[0526]

[0527] c2 is determined in the same way as in the paper “3D Modeling and Mold Design of C / E Composite Grid Winding Structure” [J]. Spacecraft Technology, 2010,

[0528] 40(4)23-26).

[0529] c2= p0cosβ (105)

[0530] where

[0531] Substitute equation (105) into equation (104) to get:

[0532]

[0533] Integrate equation (100) and equation (106) to get the parametric equation of the three-dimensional curve of the conical segment helix about θ:

[0534]

[0535] The helix with equal helix angle on the conical side is the same as the conclusion given in "Three-dimensional modeling and mold design of C / E composite grid winding structure", and the solving process is much simpler than that in "Three-dimensional modeling and mold design of C / E composite grid winding structure". Only the parametric equation of the conical surface is brought into the formula of the angle between the tangent vectors of the two curves, and the solution can be obtained. This shows that the conclusion derived from the non-developable surface is still applicable on the developable surface. The developable surface can be regarded as a special case of the hyperbolic non-developable surface when R1→∞.

[0536] The equation of the equal helix angle helix on the conical segment of the storage tank to be designed in this paper:

[0537]

[0538] 11.3) Equal helix angle helix on the lower ellipsoidal surface

[0539] The equal helix angle helix on the lower ellipsoidal surface:

[0540]

[0541] where:

[0542]

[0543] The equal helix angle helix shell can be designed to be orthogonal to itself; as mentioned earlier, the short-range line with the same start and end point on the upper head is approximately orthogonal to the equal pitch helix. The fiber tows are placed obliquely and orthogonally along the helix, which can increase the interlayer shear resistance for skin laying. Figure 28 The equal helix angle helix on the conical storage tank is obliquely placed grid.

[0544] 12) Dense helix on the surface of the conical storage tank

[0545] 12.1) Dense helix on the ellipsoidal surface of the upper head

[0546] Substitute formula (57) and formula (65) into formula (9):

[0547]

[0548]

[0549] Since the upper limit of integration is φ 5终 = 67.69267378°, the value range of φ0is 67.69267378°-90°. When , the included angle between the two end points of the close-packed spiral on the upper head surface is The minimum is:

[0550]

[0551] The included angle between the two end points of the other three kinds of spiral on the upper head surface is Δθ5=75.85746097°, so the close-packed spiral on the upper head surface cannot pass through the same two end points with the other three kinds of spiral on the upper head surface.

[0552] Let: φ 0上 = 67.69267378°.

[0553] The equation of the close-packed spiral on the upper head ellipsoidal surface is:

[0554]

[0555] 11.2) Close-packed spiral on the conical surface

[0556] The spiral angle at the tangent point between the conical surface and the upper head ellipsoidal surface is calculated by formula (57):

[0557]

[0558] Solve α 锥密排上 = 67.36707574°

[0559] Substitute formula (100) into formula (9):

[0560]

[0561] The tangent point between the conical surface and the upper head ellipsoidal surface is z4=1357.724134, tanα 锥密排上 = 2.398460049, and z0=522.487234 is solved.

[0562] From formula (115):

[0563]

[0564] Integrate and take the integration constant as 0, to obtain:

[0565]

[0566] Helix for constant thickness skin layup.

[0567] In order to make the close-packed helix on the tank smooth and continuous, the equation of the close-packed helix on the conical surface of the tank to be designed in this paper is:

[0568]

[0569] where z0=522.4872349.

[0570] 12.3) Close-packed helix on lower ellipsoidal surface

[0571] From equation (115):

[0572]

[0573] z0=522.4872349,

[0574] z = 1772.724134 at the tangent point of the conical surface and the lower head ellipsoidal surface, tan a = 3.242140378, and a = 72.85823794°. 锥密排下 锥密排下

[0575] cos φ = 0.290714948° (121) 0下

[0576] i.e. φ = 73.09923623° 0下

[0577]

[0578]

[0579] The inclined grid of the close-packed helix of the conical tank is shown in Figure 29 ;

[0580] The comparison of the three helixes of the conical tank is shown in Figure 30 ;

[0581] 13) Connection form of the forked ring of the composite tank

[0582] ​​​​Integral type "hoop stick and wrap" structure: R625.25 arc type depression in the column segment 50mm range, the deepest 0.5mm. Aluminum alloy ring type design as a whole, with column segment processing R625.25 arc type convex chord height 0.5mm; its column segment part open 24 slots of 2mm, 30° apart. When installing, the pressure is applied to the aluminum alloy ring type flange, which pushes the arc convex to the column segment arc depression (installation method similar to expansion screws, also can open 48 slots of 2mm to reduce the rigidity of the column segment arc convex, or use special tools to expand the aluminum alloy ring type column segment, and then press it back after installation); and with glue, the arc type of the aluminum alloy ring and the storage tank cooperates with each other, and at the same time, the 0.5mm composite material is wound and solidified within 50mm of the column segment.

[0583] Cross-section view of fork ring Figure 31 ; the outer surface of the fork ring is unfolded Figure 32 .

[0584] 14) Elliptical spiral arc length calculation

[0585] In order to facilitate the automatic winding and automatic laying of the fiber tows of the composite material inclined grid storage tank, the length of the spiral line on the ellipsoid is calculated. The length of the equal pitch, equal spiral angle, densely packed spiral line and geodesic on the ellipsoid head surface can be integrated. Let the angle between the ellipsoid generatrix tangent and the Z axis be γ,

[0586]

[0587] The arc length of the geodesic on the ellipsoid:

[0588]

[0589] From equation (15), for the arc length between the two end points of the geodesic on the ellipsoid head surface of the cylindrical storage tank:

[0590]

[0591] The arc length of the equal pitch spiral line on the ellipsoid:

[0592]

[0593] From equation (35), for the arc length between the two end points of the equal pitch spiral line on the ellipsoid head surface of the cylindrical storage tank:

[0594]

[0595] The arc length of the equal spiral angle spiral line on the ellipsoid:

[0596]

[0597] From equation (46), for the arc length between two end points of the equi-spiral angle helix on the ellipsoid surface of the cylindrical tank upper head:

[0598]

[0599]

[0600] Arc length of the close-packed helix on the ellipsoid surface:

[0601]

[0602] From equation (56), when φ0=71.79004314°, for the arc length between two end points of the close-packed helix on the ellipsoid surface of the cylindrical tank upper head:

[0603]

[0604] The present application has been described in detail by combining the specific embodiments and exemplary examples, but these descriptions cannot be understood as limiting the present application. It is understood by those skilled in the art that various equivalent substitutions, modifications or improvements can be made to the technical solutions and embodiments of the present application without departing from the spirit and scope of the present application, and these all fall within the scope of the present application. The scope of protection of the present application is subject to the appended claims.

[0605] The contents not described in detail in the specification of the present application are the known technology of those skilled in the art.

Claims

1. An automated forming compound material canted grid bin, comprising: The upper end and the lower end of the middle section are connected with the upper end cover and the lower end cover respectively, the upper end cover and the lower end cover are both ellipsoidal, and the middle section is a column section or a cone section, and the upper end cover and the lower end cover are provided with circular holes; The upper end cover, the lower end cover and the middle section all comprise an oblique grid structure composed of bidirectional spiral ribs and a skin wrapped outside the oblique grid structure; The outer profile center line of the bidirectional spiral rib is an equi-pitch spiral line, an equi-helix angle spiral line or a geodesic line, and the outer profile center lines of the bidirectional spiral ribs of the upper end cover, the middle section and the lower end cover are smooth and continuous; The bidirectional spiral rib with the outer profile center line being the equi-pitch spiral line, the equi-helix angle spiral line and the geodesic line is respectively denoted as an equi-pitch bidirectional spiral rib, an equi-helix angle bidirectional spiral rib and a geodesic bidirectional spiral rib, the equi-pitch bidirectional spiral rib and the equi-helix angle bidirectional spiral rib are automatically laid and formed, and the geodesic bidirectional spiral rib is automatically and continuously wound and formed; when the middle section is a column section, the column-shaped storage tank is divided into two parts by the middle section, and the two parts are formed respectively; The thickness of the skin is denoted as t, the bidirectional spiral ribs of the two parts and the skin with the thickness of t / 3 are formed first, and thickened areas are additionally formed at the joint of the two parts, the recessed areas matched with each other are processed at the thickened areas of the two parts after solidification, the two parts are inserted through the recessed areas, the skin with the remaining thickness of 2t / 3 is formed, secondary solidification is performed, and the column-shaped storage tank is obtained; When the middle section is a cone section, the conical storage tank is divided into a first part and a second part by the maximum diameter of the conical storage tank, and the first part and the second part are formed respectively, wherein the first part comprises the upper end cover and the lower end cover with smaller diameters, the cone section and a part of the upper end cover and the lower end cover with larger diameters, and the second part comprises another part of the upper end cover and the lower end cover with larger diameters; When the conical storage tank is formed, transition sections are additionally processed on the first part and the second part, the first part and the second part are inserted through the transition sections, and the conical storage tank is obtained; The transition section is a column section, and the bidirectional spiral rib of the transition section is formed according to a transition section column surface geodesic line equation, wherein the transition section column surface geodesic line equation is: wherein a 柱过渡 is the angle between the tangent to the transition section cylindrical generatrix and the tangent to the transition section cylindrical helix. When the transition section cylindrical asper and the conical tank asper are smoothly continuous, α 柱过渡 = 16.7050855°, the transition section angle is 4.5°, and the transition section length is 125.7225224 mm.

2. An automated forming fabric composite oblique grid bin as in claim 1, wherein, When the middle section is a column section, the column-shaped storage tank is obtained: The ellipsoidal surface equation of the upper end cover of the column-shaped storage tank is: Wherein, (x1, y1, z1) is the coordinates of any point in the coordinate system o1x1y1z1, a and b are the long semi-axis length and the short semi-axis length of the ellipsoidal surface respectively; The parametric equation of the ellipsoidal surface generatrix of the upper end cover of the column-shaped storage tank is: Wherein, (y1, z1) is the coordinates of any point on the y1o1z1 plane in the coordinate system o1x1y1z1, and φ1 is the angle between the vector from the coordinate origin o1 on the y1o1z1 plane and the y1 axis, and the angle satisfies the parametric equation of the ellipsoidal surface generatrix of the upper end cover of the column-shaped storage tank; The outer profile center line of one of the spiral ribs in the bidirectional geodesic rib is an ellipsoidal surface geodesic line in the upper end cover and the lower end cover, and a column surface geodesic line in the column section; The bidirectional geodesic rib of the ellipsoidal surface of the upper end cover of the column-shaped storage tank comprises two symmetrical geodesic lines, and the equation of one of the geodesic lines is: wherein θ1 is the angle between the projection of the vector from point (0, 0, z1) to point (x1, y1, z1) on the x1o1y1 plane and the x1 axis, θ1 is the angle between the projection of the vector from point (0, 0, z1) to point (x1, y1, z1) on the x1o1y1 plane and the x1 axis, 短程线 φ1 is the angle between the tangent of the generatrix of the ellipsoid surface at φ1 = 0 and the tangent of the brachistochrone of the ellipsoid surface; k is the ratio of the major axis to the minor axis of the ellipsoid surface, and the value range of k is [1.6, 2]; The coordinates of any point in the coordinate system o2x2y2z2 are denoted as (x2, y2, z2), and the column surface geodesic line equation is: The length L of the column segment is brought into the third equation of the above equation set, and z2=L, and the angle difference Δθ2 between the end points of the short-range line of the cylindrical surface can be calculated; Wherein, θ2 is the angle between the projection of the vector from point (0, 0, z2) to point (x2, y2, z2) on the x2o2y2 plane and the x2 axis, R is the radius of the cylindrical surface, R=a; The ellipsoid surface equation of the lower head of the cylindrical tank is: Wherein, (x3, y3, z3) is the coordinates of any point in the coordinate system o3x3y3z3; The parametric equation of the generatrix of the ellipsoid surface of the lower head of the cylindrical tank is: Wherein, (y3, z3) is the coordinates of any point on the y3o3z3 plane in the coordinate system o3x3y3z3, and φ3 is the angle between the vector from the coordinate origin o3 on the y3o3z3 plane and the y3 axis, which satisfies the parametric equation of the generatrix of the ellipsoid surface of the lower head of the cylindrical tank; The short-range line equation of the ellipsoid surface of the lower head of the cylindrical tank is: where θ3 is the angle between the projection of the vector from point (0, 0, z3) to point (x3, y3, z3) on the x3o3y3 plane and the x3 axis, θ3 is the angle between the projection of the vector from point (0, 0, z3) to point (x3, y3, z3) on the x3o3y3 plane and the x3 axis, The center line of the outer contour surface of one of the equal-pitch double-direction helical ribs is an ellipsoid surface equal-pitch helix on the upper head and the lower head, and a cylindrical surface equal-pitch helix on the column segment; The equal-pitch helix equation of the ellipsoid surface of the upper head of the cylindrical tank is: The cylindrical surface equal-pitch helix equation of the cylindrical tank is: The equal-pitch helix equation of the ellipsoid surface of the lower head of the cylindrical tank is: in, θ1 represents the constant pitch helix of the ellipsoidal surface of the upper head; θ3; α represents the constant pitch helix of the ellipsoidal surface of the lower head. 等螺距 The angle between the tangent to the generatrix of the ellipsoidal surface at φ1=0 and the tangent to the helix of the ellipsoidal surface with equal pitch; k 柱等螺距 yes The proportionality coefficient between sinφ1 and the upper and lower end caps, for a tank with a column section in the middle, is k. 柱等螺距 same; The center line of the outer contour surface of one of the equal-helix-angle double-direction helical ribs is an ellipsoid surface equal-helix-angle helix on the upper head and the lower head, and a cylindrical surface equal-helix-angle helix on the column segment; The equal-helix-angle helix equation of the ellipsoid surface of the upper head of the cylindrical tank is: The cylindrical surface equal-helix-angle helix equation of the cylindrical tank is: The equal-helix-angle helix equation of the ellipsoid surface of the lower head of the cylindrical tank is: wherein, θ1 is the θ of the equal helix angle helix of the ellipsoidal surface of the upper head of the cylindrical tank; θ3 is the θ of the equal helix angle helix of the ellipsoidal surface of the lower head of the cylindrical tank; and 等螺旋角 α is the angle between the tangent of the generatrix of the ellipsoidal surface and the tangent of the equal helix angle helix of the ellipsoidal surface. The coordinate system o1x1y1z1 takes the rotation axis of the cylindrical tank as the z1 axis, takes the intersection point of the z1 axis and the ellipsoid of the upper head and the column segment as the origin, the z1 axis points to the top end of the upper head from the origin, and the x1o1y1 plane is perpendicular to the z1 axis; the coordinate system o2x2y2z2 takes the rotation axis of the cylindrical tank as the z2 axis, the origin is the same as the coordinate system o1x1y1z1, the z2 axis is opposite to the z1 axis, and the x2 axis coincides with the x1 axis; the coordinate system o3x3y3z3 takes the rotation axis of the cylindrical tank as the z3 axis, takes the intersection point of the z3 axis and the ellipsoid of the lower head and the column segment as the origin, the z3 axis is the same as the z2 axis, and the x3 axis forms an angle Δθ2 with the x1 axis, the angle is positive when the x1 axis points to the x3 axis counterclockwise around the z3 axis; the above three coordinate systems are right-handed coordinate systems.

3. An automated forming fabric composite oblique grid bin as in claim 2, wherein, When a=400 mm, b=250 mm, and the column segment height L=408 mm; For the head and the lower head of the circular hole diameter of 250 mm, and with this circular hole as the polar hole, the short-range line two-way spiral rib, α 短程线 = 18.20995686°; For the ellipsoid surface equal pitch helix whose start point at the intersection of the short-range line of the above head ellipsoid surface and the cylinder segment and end point at the circular hole of the head ellipsoid surface coincide, k 柱等螺距 = 87.20389426; When the ellipsoid profile constant-pitch helix and the cylindrical constant-pitch helix are smoothly continuous, α 等螺距 = 67.67472979°.

4. An automated forming fabric composite oblique grid bin as in claim 3, wherein, The starting points and ending points of the helixes of the tank surface of the three intermediate segments are coincident with the column segment; The cross sections of the bidirectional spiral rib are all mutually fully equivalent trapezoids, the geometric dimensions of the trapezoidal cross section are adjusted according to the bearing condition, and the height-width ratio is valued in the range of The trapezoidal cross section is perpendicular to the center line of the outer surface of the bidirectional spiral rib, the center line of the trapezoidal cross section points to the normal direction of the tank surface, the upper base and the lower base of the trapezoidal cross section are respectively located on the inner surface of the tank and the outer surface of the tank, and the midpoint of the lower base is swept along the center line of the outer contour surface of the bidirectional spiral rib to form the bidirectional spiral rib.

5. An automated forming fabric composite grid storage bin according to claim 2, wherein, When the intermediate segment is a column segment: The skin is automatically laid according to the close-packed helix equation; The ellipsoid surface equations of the upper head and the lower head are: The close-packed helix equation of the ellipsoid surface of the upper head of the cylindrical tank is: The close-packed helix equation of the cylindrical surface is: The close-packed helix equation of the ellipsoid surface of the lower head of the cylindrical tank is: φ0 is the included angle between the tangent of the generatrix of the ellipsoidal surface of the cylindrical storage tank and the tangent of the densely packed spiral line of the ellipsoidal surface when φ1 is 0; θ1 is the θ1 of the densely packed spiral line of the ellipsoidal surface of the upper head of the cylindrical storage tank; θ3 is the θ3 of the densely packed spiral line of the ellipsoidal surface of the lower head of the cylindrical storage tank.

6. An automated forming fabric composite grid storage bin according to claim 1, wherein, When the intermediate segment is a conical segment, it is a conical tank: The outer profile surface center line of one of the helical ribs in the conical tank short-range line two-way helical rib is a conical surface short-range line in the conical section, and is an upper conical tank ellipsoidal surface short-range line and a lower conical tank ellipsoidal surface short-range line in the upper and lower heads of the conical tank respectively; The conical surface short-range line equation is: wherein (x4, y4, z4) is the coordinate of any point in the coordinate system o4x4y4z4; z 下 is the distance from the conical vertex where the conical surface is located to the lower end surface of the truncated cone. z is the distance from the apex of the cone where the taper is located to the upper end surface of the truncated cone 上 Substituting the above equation group 4, the angle difference between the upper end point and the lower end point of the tangent of the truncated cone can be calculated That is, The upper conical tank ellipsoidal surface equation is: Wherein, (x5, y5, z5) is the coordinate of any point in the coordinate system o5x5y5z5; The upper conical tank ellipsoidal surface generatrix parameter equation is: Wherein, (y5, z5) is the coordinate of any point in the y5o5z5 plane of the coordinate system o5x5y5z5, and φ5 is the angle between the vector from the coordinate origin o5 and the y5 axis in the y5o5z5 plane, which satisfies the upper conical tank ellipsoidal surface generatrix parameter equation; The upper conical tank ellipsoidal surface short-range line equation is: φ 5切 φ5is the angle of the tangent line of the conic generatrix and the elliptic generatrix of the ellipsoidal surface of the upper head of the conical tank at the point φ5, and the angle difference between the short line φ5= 0 and the short line φ5= φ5= φ4at the point φ4of the upper head of the conical tank can be calculated by the fourth equation of the above equation set 5切 ​ That is, The lower conical tank ellipsoidal surface equation is: Wherein, (x6, y6, z6) is the coordinate of any point in the coordinate system o6x6y6z6; The lower conical tank ellipsoidal surface generatrix parameter equation is: Wherein, (y6, z6) is the coordinate of any point in the y6o6z6 plane of the coordinate system o6x6y6z6, and φ6 is the angle between the vector from the coordinate origin o6 and the y6 axis in the y6o6z6 plane, which satisfies the lower conical tank ellipsoidal surface generatrix parameter equation; The lower conical tank ellipsoidal surface short-range line equation is: φ 6切 φ6is the angle of the tangent line of the conical generatrix and the ellipsoidal surface of the lower head of the conical tank at the point of tangency of the elliptic generatrix of the ellipsoidal surface, which can be calculated from the fourth equation of the above equation set as φ6= 0 and the angle difference between φ6= φ 6切 That is: ​ The coordinate system o4x4y4z4 takes the conical rotary axis as the z4 axis, takes the conical vertex as the origin, the z4 axis points to the lower end surface of the truncated cone from the origin, and the x4o4y4 plane is perpendicular to the z4 axis; the z5 axis of the coordinate system o5x5y5z5 is opposite to the z4 axis, the distance between the origin o5 and the origin o4 is z 上 +b 上 sinφ 5切 , the included angle between the x5 axis and the x4 axis is The included angle is positive in the counterclockwise direction of the x4 axis to the x5 axis around the z5 axis; the z6 axis of the coordinate system o6x6y6z6 is the same as the z4 axis, the distance between the origin o6 and the origin o4 is z 下 +b 下 sinφ 6切 , the included angle between the x6 axis and the x4 axis is The included angle is positive in the counterclockwise direction of the x4 axis to the x6 axis around the z5 axis; the above three coordinate systems are right-handed coordinate systems; Wherein, θ4 is the angle between the projection of the vector from point (0, 0, z4) to point (x4, y4, z4) on the x4o4y4 plane and the x4 axis, θ5 is the angle between the projection of the vector from point (0, 0, z5) to point (x5, y5, z5) on the x5o5y5 plane and the x5 axis, θ6 is the angle between the projection of the vector from point (0, 0, z6) to point (x6, y6, z6) on the x6o6y6 plane and the x6 axis, β is the half-cone angle of the conical section, φ is the angle between the projection of the vector from point (0, 0, z) to point (x, y, z) on the xoy plane and the x axis, 孔 D is the diameter of the circular hole provided on the upper and lower heads, a 上 and b 上 are the long and short semi-axis lengths of the ellipsoidal surface of the upper head, respectively, a 下 and b 下 are the long and short semi-axis lengths of the ellipsoidal surface of the lower head, respectively, α' 上 and α' 下 are the angles between the tangent of the ellipsoidal surface generatrix at the tangent point of the conical generatrix and the tangent of the ellipsoidal surface short-range line, respectively; k 上 and k 下 are the ratios of the long and short axes of the ellipsoidal surface of the upper head and the ellipsoidal surface of the lower head, respectively; The outer profile surface center line of one of the helical ribs in the equal-pitch two-way helical rib is an upper head ellipsoidal surface equal-pitch helix and a lower head ellipsoidal surface equal-pitch helix in the upper and lower heads respectively, and is a conical surface equal-pitch helix in the conical section; The conical surface equal-pitch helix equation is: z 上 and z 下 Substituting the above equation group 3rd equation and subtracting, the angle difference between the upper end point and the lower end point of the equal pitch helix on the truncated cone surface can be calculated That is, In order to make the upper end point of the conical surface equal-pitch helix coincide with the upper end point of the conical surface short-range line, the conical surface equal-pitch helix is rotated counterclockwise around the z4 axis: The upper conical tank ellipsoidal surface equal-pitch helix equation is: From the 4th equation of the above equation set, the angle difference between the φ5=0 and φ5=φ 5切 at the ellipsoidal surface of the upper head of the constant-pitch helix can be calculated i.e. In order to make the equal pitch helix smooth and continuous, the equal pitch helix of the ellipsoid surface of the lower head of the conical storage tank is counterclockwise rotated around the z5 axis: The equation of the equal pitch helix of the ellipsoid surface of the lower head of the conical storage tank is: From the 4th equation of the above equation set, the angle difference between the φ6=0 and φ6=φ 6切 at the ellipsoidal surface of the lower head and the equal pitch helix at the φ6=φ i.e. In order to make the lower conical tank ellipsoidal surface equal-pitch helix smooth and continuous, the lower conical tank ellipsoidal surface equal-pitch helix is rotated counterclockwise around the z6 axis: wherein a 等螺距 is a proportionality coefficient of the conical surface constant-pitch helix, is θ5 of the ellipsoidal surface constant-pitch helix, is θ6 of the ellipsoidal surface constant-pitch helix, K 上 and K 下 are proportionality coefficients of the upper head ellipsoidal surface and the lower head ellipsoidal surface, respectively; The outer profile surface center line of one of the helical ribs in the equal-helix-angle two-way helical rib is an upper head ellipsoidal surface equal-helix-angle helix and a lower head ellipsoidal surface equal-helix-angle helix in the upper and lower heads respectively, and is a conical surface equal-helix-angle helix in the conical section; The conical surface equal-helix-angle helix equation is: ρ is the length of the generatrix of the truncated cone from the vertex of the cone to the lower end surface of the truncated cone 下 The angle difference between the upper end point and the lower end point of the helix with the same helix angle on the truncated cone surface can be calculated by substituting the above equation group into the fourth equation and subtracting That is, In order to make the upper end point of the conical surface equal-helix-angle helix coincide with the upper end point of the conical surface short-range line, the conical surface equal-helix-angle helix is rotated counterclockwise around the z4 axis: The equation of the helix with the same helix angle of the ellipsoid surface of the conical tank upper head is: From the 4th equation of the above equation set, the angle difference between the ellipsoid surface of the upper head and the helix line with equal helix angle φ5=0 and φ5=φ at φ5=φ can be calculated. 5切 ​ That is: To make the equal-helix-angle helix smooth and continuous, the ellipsoid surface of the upper head is rotated counterclockwise around the z5 axis: The lower conical tank ellipsoidal surface equal-helix-angle helix equation is: From the 4th equation of the above equation set, the angle difference between the φ6=0 and φ6=φ 6切 at the ellipsoidal surface of the lower head with the same helix angle φ6 can be calculated. That is, To make the equal helix angle helix smooth and continuous, the lower head ellipsoidal surface equal helix angle helix rotates counterclockwise around the z6 axis: wherein p is the length of the conic generatrix, θ5 is the θ of the upper head ellipsoidal surface equal-pitch spiral line, θ6 is the θ of the lower head ellipsoidal surface equal-pitch spiral line; φ 锥上 α is the upper end diameter of the conical surface, 锥等螺旋角 k is the included angle between the tangent of the conical tank surface generatrix and the tangent of the conical tank surface equal-pitch spiral line, 上 and k 下 are the ratios of the major and minor axes of the upper head ellipsoidal surface and the lower head ellipsoidal surface, respectively; inverse hyperbolic sine function arctangent function 7. An automated forming fabric composite grid storage bin according to claim 6, wherein, φ 锥上 = 727.602 mm, φ 锥下 = 950 mm, h = 415 mm, β = 15°, φ 孔 = 280 mm; k 上 = 1.60529632, k 下 = 1.60529632, a 上 = 368.8340882 mm, b 上 = 229.7607511 mm, a 下 = 480.4025512 mm, b 下 = 299.9891610 mm, a' 上 = 22.30732623°, a' 下 = 16.90075971°; K = 99.74378385; when the start point and the end point of the upper head ellipsoid surface equi-pitch helix and the upper head ellipsoid surface short-range line coincide, the start point and the end point of the lower head ellipsoid surface equi-pitch helix and the lower head ellipsoid surface short-range line coincide 上 = 99.74378385; a 等螺距 = 136.6372015, K 下 = 130.5270084; When the start point and the end point of the upper head ellipsoidal surface equal-helix-angle helix line coincide with the start point and the end point of the upper head ellipsoidal surface short-range line, and the start point and the end point of the lower head ellipsoidal surface equal-helix-angle helix line coincide with the start point and the end point of the lower head ellipsoidal surface short-range line, α 锥等螺旋角 = 48.01224003°.

8. An automated forming fabric composite grid storage bin according to claim 6, wherein, When the middle section is a conical section: The skin is automatically laid according to the close-packed helix equation; The conical surface close-packed helix equation is: z is the distance from the apex of the cone where the taper is located to the upper end face of the truncated cone 上 z is the distance from the apex of the cone where the taper is located to the lower end face of the truncated cone 下 Substituting the above equation group 4 and subtracting, the angle difference between the upper end point and the lower end point of the close-packed helix on the truncated cone surface can be calculated That is, To make the end point of the helix on the truncated cone coincide with the end point of the short line on the truncated cone, rotate counterclockwise about the z4 axis: The upper conical tank ellipsoidal surface close-packed helix equation is: φ 0上 φ5is the angle between the tangent of the generatrix of the ellipsoidal surface of the upper head of the conical tank and the tangent of the close-packed helical line of the ellipsoidal surface of the upper head when φ5= 0; the angle difference between φ5= 0 and φ5= φ 5切 ​ That is, In order to make the upper conical tank ellipsoidal surface close-packed helix smooth and continuous, the upper conical tank ellipsoidal surface close-packed helix is rotated counterclockwise around the z5 axis: The lower conical tank ellipsoidal surface close-packed helix equation is: φ 0下 The angle φ6 is the angle between the tangent of the generatrix of the ellipsoidal surface of the lower head of the conical tank and the tangent of the close-packed helical line of the ellipsoidal surface of the lower head when φ6 = 0. The angle difference between φ6 = 0 and φ6 = φ 6切 ​ That is, In order to make the close-packed helix smooth and continuous, the close-packed helix of the lower head ellipsoidal surface is rotated counterclockwise around the z6 axis:

9. An automated forming fabric composite grid storage bin according to claim 1, wherein, The arc length of the upper helix of the upper and lower head ellipsoidal surfaces is determined according to the following formula: The arc length of the short-range helix of the tank ellipsoidal surface is: The arc length of the upper equal-pitch helix of the column tank ellipsoidal surface when the middle section is a column section is: The arc length of the upper equal-helix-angle helix of the column tank ellipsoidal surface when the middle section is a column section is: Arc length calculation of close-packed helix on ellipsoid surface of storage tank: Wherein, γ is the included angle between the tangent of the ellipsoidal profile generatrix and the Z axis, α is the included angle between the tangent of the ellipsoidal profile generatrix and the helix tangent, φ is the parameter of the elliptic parameter equation on the yoz plane, (y, z) is the coordinate of any point on the ellipsoidal profile generatrix in the coordinate system oxyz, φ0 is the φ when the included angle between the tangent of the ellipsoidal profile generatrix and the tangent of the densely arranged helix of the ellipsoidal profile is 0; φ 起点 is the φ at the starting point of the sought ellipsoidal profile helix; φ 终点 is the φ at the terminal point of the sought ellipsoidal profile helix; b is the short axis length of the ellipsoidal profile; the coordinate system oxyz takes the storage tank ellipsoidal profile rotation axis as the z axis, takes the intersection of the z axis and the ellipsoidal lower end face as the origin, the z axis points to the ellipsoidal top end from the origin, and the xoy plane is perpendicular to the z axis.

10. An automated forming compound material oblique grid bin according to claim 1, wherein, The storage tank is connected with the external forked ring, and the connection form of the storage tank and the external forked ring is: The column section of the storage tank is processed into a circular arc type depression, the aluminum alloy ring type piece is processed into a circular arc type protrusion matched with the circular arc type depression, the aluminum alloy ring type piece is glued between the column section, the protrusion of the aluminum alloy ring type piece and the depression of the column section are mutually clamped, and the composite material is wound at the connection between the aluminum alloy ring type piece and the column section and is solidified.

11. A forming tool for automatically forming a composite material oblique grid storage box according to any one of claims 1-10, characterized in that, The grid mold of the storage tank head made of silicone rubber is formed by stereoscopic casting; When the grid mold of the storage tank head made of silicone rubber is formed by stereoscopic casting, the silicone rubber male mold is used as the mold; A suitable tangent plane is selected, so that the distance between the four corners of the grid mold of the storage tank head made of silicone rubber and the tangent plane is equal, and the pouring port is arranged on the side of the silicone rubber male mold without the grid rib groove; The calculation method of the normal direction of each point of the helix on the grid mold of the storage tank head made of silicone rubber is: The unit normal vector of the curved surface is: wherein E, F, G are first base quantities: F＝r φ ·r θ 、 r = |g (φ) cosθ, g (φ) sinθ, f (φ)| r = |acosφcosθ, acosφsinθ, bsinφ| Thus, the normal direction of each point on the short-range line of the ellipsoid surface is obtained, which is used to ensure that the helical rib of the male mold of the grid of the storage tank head made of silicone rubber is along the normal direction; when φ = φ1 and θ = θ1, the normal direction of each point on the short-range line of the ellipsoid surface of the upper head of the column-shaped storage tank is obtained; by using the above method, the normal direction of each point on the short-range line of the ellipsoid surface of the lower head of the column-shaped storage tank and the normal direction of each point on the short-range line of the ellipsoid surface of the upper and lower heads of the conical storage tank are obtained.

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