Three-dimensional woven composite material plate spring type undercarriage prefabricated body profiling forming tool and forming method

Abstract

The invention discloses a three-dimensional woven composite material plate spring type undercarriage prefabricated body profiling forming tool and method. The three-dimensional woven composite material plate spring type undercarriage prefabricated body profiling forming tool comprises a tool frame, a core mold, five clamps and five connecting rollers. The three-dimensional woven composite material plate spring type undercarriage structure prefabricated body comprises nine areas including a first uniform cross-section area, a first variable cross-section area, a second uniform cross-section area, a second variable cross-section area, a third uniform cross-section area, a third variable cross-section area, a fourth uniform cross-section area, a fourth variable cross-section area and a fifth uniform cross-section area, vertical parts are arranged on the two sides of a plate spring, an arc part is arranged in the middle of the plate spring, and the plate spring is of a symmetrical structure. The thicknesses of the fabrics in different areas are different, variable-thickness integrated weaving is adopted in the weaving process, and the fabric areas comprise binding warp yarns and weft yarns. The defects that an existing undercarriage prefabricated body is woven in blocks and cannot be integrally formed can be overcome, better size control and good mechanical performance are achieved, the three-dimensional woven composite material is adopted, and the undercarriage prefabricated body has the advantages of being large in specific stiffness and high in specific strength and further has excellent layering resistance and impact resistance.

Description

Technical Field

[0001] The invention relates to the technical field of textile machinery structures, in particular to a three-dimensional woven composite material leaf spring type landing gear preform copying molding tool and a molding method. Background Art

[0002] With the rapid development of UAVs, people have higher requirements for the take-off quality, cruising speed and energy saving and high efficiency of UAVs, and composite landing gears have emerged. Compared with high-performance metal materials such as 300M steel, 4340 steel and TC18 titanium alloy for aviation, carbon fiber reinforced composite materials not only have high strength, high modulus, good fatigue resistance and corrosion resistance, but also have the characteristics of light weight and strong designability, which are conducive to reducing the fuel consumption of UAVs and improving their endurance. Three-dimensional woven composite materials are currently the most widely used three-dimensional textile composite materials. The fabric structure introduces the binding yarn in the thickness direction, and forms an overall interlocking structure in space by connecting with the in-plane yarn, which enhances the interlayer performance of the composite material after molding, inhibits its delamination damage, and improves the impact resistance and damage tolerance. Based on the above background, the application of three-dimensional woven composite materials in landing gear will effectively solve the problems exposed in the use of the original metal landing gear, reduce the weight of the landing gear, and further improve the overall performance of ship-borne unmanned helicopters.

[0003] At present, the molding of three-dimensional woven composite landing gear preforms mostly adopts partial weaving and subsequent assembly, but the connection parts are prone to stress concentration and have poor mechanical properties. For example, patent CN110126300 provides a composite landing gear using three-dimensional weaving and a preparation method thereof, which adopts a three-point structural layout. The support center axis and the wheel rocker arm are both three-dimensionally woven components, which can achieve a lightweight design of the landing gear, but its overall structural performance is poor; CN108146617 designs and manufactures a composite leaf spring landing gear and a manufacturing method thereof, in which a foam layer is filled inside the continuous fiber shell. Although the landing gear is lightweight, the interior is a foam layer, and the load-bearing capacity is poor compared to the composite material plate, and the mechanical properties are poor.

[0004] To this end, we propose a three-dimensional woven composite leaf spring landing gear preform copy molding tool and molding method to solve the above problems. Summary of the invention

[0005] The object of the present invention is to provide a three-dimensional woven composite material leaf spring landing gear preform copying molding tool and molding method to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The first purpose is to provide a three-dimensional woven composite material leaf spring landing gear preform copying molding tool, which includes a tool frame, a core mold, five clamps, and five connecting rods.

[0008] The fixture frame 1 includes a bearing, ten shaft fans, and two pillars. The bearing is equipped with two bearing discs, a connecting rod, two arched limit blocks, and a small motor. Each bearing disc has a positioning hole at the center, and the positioning hole has a diameter of 50 mm. The lower part of the bearing disc has five symmetrically distributed "U"-shaped grooves, and each "U"-shaped groove has two limit holes, and the limit hole diameter is 16 mm. The connecting rod passes through the central positioning hole of the bearing disc to connect the two bearing discs horizontally. Each bearing disc has an arched limit block on the outside. The diameter of the connecting rod matches the arc diameter of the positioning hole and the arched limit block. The two arched limit blocks are symmetrically distributed, and the lower ends of the two arched limit blocks are connected to the pillars and connected by welding. The shaft fan is runway-shaped, with a length of 1200mm and an arc diameter of 16mm. There are two limit holes at the upper end, corresponding to the size of the 'U'-shaped groove of the bearing disk. There is a runway-shaped hole at the lower end, with a length of 400mm and a distance of 27mm from the lower end of the shaft fan. The ten shaft fans correspond to the 'U'-shaped grooves on the two bearing disks. There are five shaft fans on each bearing disk, which are fixed by bolts passing through the 'U'-shaped groove and the limit holes at the upper end of the shaft fan.

[0009] The core mold is an arched symmetrical structure, each side is composed of sixteen 'Z'-shaped core blocks and one vertical core block, connected by a convex core block in the middle, the upper ends of the two vertical core blocks are curved, and are embedded with the lower ends of the 'Z'-shaped core blocks. Each core block is provided with a positioning hole, and a connecting rod passes through the positioning hole and the 'U'-shaped groove on the shaft fan to connect the core mold to the tooling frame, and is fixed with a hexagonal nut to complete the combination of the core mold and the tooling frame; a small motor is provided on the right side of the bearing, so that the ten shaft fans drive the core mold to rotate around the bearing to realize the rotation of the tooling;

[0010] The clamp is composed of two clamps and two small connecting rods. Positioning holes are provided at both ends of the clamps. The diameter of the positioning holes is 16 mm. During the weaving process, one side of the clamp is close to the core mold and the other side is close to the fabric. Two small connecting rods are used to connect through the positioning holes and the two clamps are clamped by hexagonal nuts to make the fabric fit the core mold better and achieve the purpose of shape-matching.

[0011] The second object is to provide a three-dimensional woven composite leaf spring landing gear structure preform including nine regions of equal cross-section region 1, variable cross-section region 1, equal cross-section region 2, variable cross-section region 2, equal cross-section region 3, variable cross-section region 3, equal cross-section region 4, variable cross-section region 4, and equal cross-section region 5. The two sides of the leaf spring are vertical parts, the middle is an arc part, and the structure is symmetrical. The fabric thickness of different regions is different. Variable thickness integrated weaving is adopted in the weaving process. The fabric region includes binding warp yarns and weft yarns. The specific parameters of the fabric are set as follows:

[0012] The developed fabric has an arch height of 500mm and a span of 2000mm. The inner length of the entire leaf spring is 2368mm and the width is 185mm. The length of the equal-section area 1 is 100mm, the arc length of the variable-section area 1 is 20mm, the length of the equal-section area 2 is 264mm, the length of the variable-section area 2 is 443mm, and the length of the equal-section area 3 is 714mm. It has a symmetrical structure. The length of the variable-section area 3 is equal to that of the variable-section area 2, the length of the equal-section area 4 is equal to that of the equal-section area 2, the length of the variable-section area 4 is equal to that of the variable-section area 1, and the length of the equal-section area 5 is equal to that of the equal-section area 1.

[0013] The warp yarn is TG800H-12K carbon fiber three-ply, and the weft yarn is TG800H-12K single-ply;

[0014] The density of the warp yarns is 4 / cm, and the density of the weft yarns is 5 / cm;

[0015] The number of binding warp yarn rows n = fabric width × warp yarn density = 185 / 10 × 4 = 74 rows;

[0016] The volume content of fabric fiber is controlled at about 57%.

[0017] The third object is to provide a method for preparing a three-dimensional woven composite material leaf spring landing gear structure preform, wherein the weaving method comprises the following steps:

[0018] S1, tooling preparation, initial yarn arrangement of the fabric, 74 rows of warp yarn, and then weft insertion. According to the thickness of the fabric, the number of weft insertion layers in each area is calculated;

[0019] S2, weaving of uniform cross-section area 1:

[0020] S2-1, the fabric in this area is in a vertical shape and the thickness does not change. The fabric thickness is measured to be 25 mm, and the number of warp and weft yarn layers introduced is calculated. At the same time, the weaving tooling is controlled during the weaving process to ensure that the fabric thickness is evenly distributed. The fabric thickness is measured every 20 mm during the weaving process to ensure that its thickness distribution is the same;

[0021] S2-2, further, according to the thickness of the fabric, the number of warp yarn layers introduced is 33 layers, and the number of weft yarn layers is 34 layers. At the same time, during the weaving process, four hexagonal nuts in the clamp are used to clamp the fabric and the core mold with two clamps to ensure that they are close to the inside of the core mold to achieve the purpose of profiling. After the inner length of the woven landing gear preform reaches 100 mm, it enters the next area for weaving;

[0022] S3, weaving of variable cross-section area 1:

[0023] S3-1, this area is a variable thickness area, which is in the shape of a "corner". The inner length of the fabric is 20mm, and the fabric thickness increases from 25mm to 26mm and then decreases to 20mm. The addition and subtraction of yarn layers during the weaving process are designed to achieve the change of fabric thickness, and the bending shape of the fabric is ensured by controlling the angle of the weaving tooling;

[0024] S3-2, further, when the total inner length of the fabric is 100mm, the yarn is added, the warp yarn is added one layer, becoming 34 layers, the weft yarn is 35 layers, and the fabric thickness reaches 26mm, and then the yarn is reduced, and one layer of outer warp yarn is reduced for each weft, and a total of 8 layers are reduced. At this time, the warp yarn has 26 layers. At the same time, during the weaving process, the motor is used to drive the shaft fan to rotate around the bearing to control the angle of the weaving tooling, so that the cloth mouth is always parallel to the yarn direction. At the same time, the clamp is used to make the fabric fit better with the core mold to achieve shape-matching molding. When the inner length of the preform reaches 120mm, it enters the next area for weaving;

[0025] S4, weaving of equal cross-section area 2:

[0026] S4-1, the fabric thickness in this area does not change. The fabric thickness is still 20mm. The design introduces the number of warp and weft yarn layers. The fabric in this area has a certain curvature. Therefore, tooling is used to ensure the fabric bending surface to achieve profiling. At the same time, the fabric thickness is measured every 20mm during the weaving process to ensure that there is no obvious deviation in the fabric thickness.

[0027] S4-2, further, the number of warp yarn layers is calculated to be 26 layers, the number of weft yarn layers is calculated to be 27 layers, the bearing disc is used to drive the shaft fan to rotate around the bearing by a motor to control the angle of the weaving tooling, and the clamp is used to make the fabric fit tightly to the surface of the core mold to ensure the curved surface of the fabric, and the weaving is 264 mm. At this time, the total length of the inner side of the fabric is 384 mm, and the weaving of the next area is started;

[0028] S5, weaving of variable cross-section area 2:

[0029] S5-1, the fabric thickness in this area increases evenly, the fabric has a certain curvature, and the thickness increases from 20mm to 37mm. This is achieved by uniformly adding layers of warp yarns. The angle of the weaving tooling is controlled during the weaving process to achieve better shaping of the fabric;

[0030] S5-2, further, the initial number of warp yarn layers of the fabric in this area is 26 layers, and a layer of warp yarn is added on the outside every 26 mm, and a total of 17 layers are added, so that the final fabric thickness reaches 37 mm. At this time, the number of warp yarn layers of the fabric increases to 48 layers. At the same time, during the weaving process, the bearing disk is used to drive the shaft fan to rotate around the bearing to control the angle of the weaving tooling, and the clamp is used to make the fabric fit tightly to the surface of the core mold to ensure the curved surface of the fabric. The weaving is 443 mm. At this time, the total length of the inner side of the fabric is 827 mm, and the next area is weaved;

[0031] S6, weaving of equal cross-section zone 3:

[0032] S6-1, this area is the top area of ​​the landing gear, connected to the fuselage. The fabric thickness in this area is 37mm, and the thickness does not change. At the same time, the weaving tooling is controlled during the weaving process to ensure the curvature of the fabric. The fabric thickness is measured every 20mm during the weaving process to ensure that its thickness distribution is equal;

[0033] S6-2, further, according to the thickness calculation, 48 layers of warp yarn and 49 layers of weft yarn are introduced, and no layer of warp and weft yarn is added. At the same time, during the weaving process, the splint 22 and the hexagonal nut 21 are used to make the fabric close to the surface of the core mold to ensure the curvature of the fabric. 714mm is weaved, and the inner length of the fabric reaches 1541mm, and the next area is weaved;

[0034] S7, weaving of variable cross-section zone 3:

[0035] S7-1, the variable cross-section area 3 is symmetrical with the variable cross-section area 2. The arc length of this area is 443mm, and the fabric thickness is 37mm. The fabric thickness in this area is uniformly thinned from 37mm to 20mm, which is achieved by uniformly reducing the warp yarn layer and controlling the angle of the weaving tooling to ensure the bending surface of the fabric. At the same time, the fabric thickness is measured every 20mm during the weaving process to ensure that its thickness is within a certain range without large deviations;

[0036] S7-2, further, in the initial stage, the number of warp yarn layers is 48 layers, the number of weft yarn layers is 49 layers, and the number of outer warp yarn layers is reduced by one layer every 26 mm, a total of 17 layers are reduced, and 443 mm is woven. At this time, the fabric thickness is 20 mm, and the number of warp yarn layers is reduced to 26 layers. During the weaving process, the motor is used to drive the shaft fan to rotate around the bearing to control the angle of the weaving tooling. The cloth fell is always parallel to the yarn direction, and the two clamping plates are clamped with hexagonal nuts to make the fixture clamp the fabric and the core mold to obtain a certain curved surface. At this time, the total length of the inner side of the fabric reaches 1984 mm, and it enters the next area for weaving;

[0037] S8, weaving of equal cross-section zone 4:

[0038] S8-1, the equal-section area 4 is symmetrical with the equal-section area 2. This area is an equal-thickness area with a thickness of 20 mm. The thickness is evenly distributed without obvious changes. The thickness of the fabric is measured every 20 mm during the weaving process to ensure that its thickness is evenly distributed. The bending profile of the fabric is ensured by controlling the angle of the weaving tooling.

[0039] S8-2, further, according to the thickness calculation, 26 layers of warp yarn and 27 layers of weft yarn need to be introduced. During the weaving process, the motor is used to drive the shaft fan to rotate around the bearing to control the angle of the weaving tooling, and the splint and hexagonal nut are used to make the fabric close to the surface of the core mold to ensure the curved surface. The weaving is 264mm. At this time, the total length of the inner side of the fabric reaches 2248mm, and the next stage of weaving is entered;

[0040] S9, weaving of variable cross-section zone 4:

[0041] S9-1, the variable cross-section area 4 is symmetrical with the variable cross-section area 1. This area is a variable thickness area. The fabric thickness increases from 20mm to 26mm and then decreases to 25mm. This is achieved by adding and subtracting layers of warp and weft yarns, and by controlling the angle of the knitting tooling, the contouring is better achieved;

[0042] S9-2, further, continuing the last weft of the previous area, the number of warp yarn layers is 26, and the warp yarn is evenly added. Each weft is woven with an outer warp yarn layer, and a total of 8 layers are added. At this time, the warp yarn has 34 layers, and the fabric thickness reaches 26mm. Then the yarn layer is reduced, and the outer warp yarn is reduced by one layer in the next weft. The warp yarn has 33 layers and the fabric thickness is 25mm. During the weaving process, the motor is used to make the bearing disk drive the shaft fan to rotate around the bearing to control the angle of the weaving tooling, and the clamp is used to make the fabric fit tightly to the surface of the core mold to ensure the curved surface of the fabric. At this time, the total length of the inner side of the fabric is 2268mm, and the next area is entered for weaving;

[0043] S10, weaving of equal cross-section zone 5:

[0044] S10-1, the equal-section area 5 is symmetrical with the equal-section area 1, which is the vertical area of ​​the landing gear. The thickness of this area does not change. The fabric thickness is 25 mm and the length is 100 mm. No yarn is added or subtracted. The fabric is better fitted to the core mold by controlling the tooling to achieve contour shaping;

[0045] S10-2. Further, according to the thickness of the fabric, 33 layers of warp yarns and 34 layers of weft yarns are introduced. During the weaving process, the fabric is pressed against the surface of the core mold using a splint and a hexagonal nut to ensure the curvature of the fabric. The fabric thickness is measured every 20 mm to ensure that there is no significant deviation in the thickness. After weaving for 100 mm, the total length of the inner side of the fabric reaches 2368 mm, and the weaving of the landing gear preform is completed.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] The present invention can solve the defects of the existing landing gear preform that the block weaving and the inability to be integrated into one shape can achieve better size control and good mechanical properties. The three-dimensional woven composite material is adopted, which not only has the characteristics of large specific stiffness and high specific strength, but also has excellent anti-delamination and impact resistance, can realize the lightweight design of the landing gear, and has good compression, bending and torsion resistance. The three-dimensional woven composite landing gear molding tooling includes a molding core mold, which can be integrated into one shape during the weaving process. The tooling can be used to better weave an ideal shape, which makes up for the defects of the previous block weaving of the landing gear and improves the overall performance of the composite landing gear. The tooling fixture can make the fabric fit tightly to the core mold during the weaving process, which solves the defects of poor thickness control during weaving in the past, and can better realize the variable thickness integrated molding of the leaf spring landing gear. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a schematic diagram of the assembly of the present invention;

[0049] Figure 2 It is a schematic diagram of the tooling of the present invention;

[0050] Figure 3 is a schematic diagram of a bearing of the present invention;

[0051] Figure 4 It is a schematic diagram of the shaft fan of the present invention;

[0052] Figure 5 It is a schematic diagram of the core mold of the present invention;

[0053] Figure 6 is a schematic diagram of the clamp of the present invention;

[0054] Figure 7 It is a schematic diagram of the fabric of the present invention divided into regions;

[0055] Figure 8 It is the main flow chart of the present invention;

[0056] Fig. 9 It is the assembly tool flow chart of the present invention;

[0057] Fig.10 It is a weaving parameter flow chart of the present invention. DETAILED DESCRIPTION

[0058] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0059] Embodiment 1

[0060] A three-dimensional woven composite material leaf spring landing gear preform copying molding tool comprises a tool frame 1, a core mold 2, five clamps 3, and five connecting rods 4.

[0061] The fixture frame 1 includes a bearing 5, ten shaft fans 6, and two pillars 7. The bearing 5 is equipped with two bearing discs 8, a connecting rod 12, two arched stop blocks 13, and a small motor 14. Each bearing disc has a positioning hole 9 at the center, and the positioning hole has a diameter of 50 mm. The lower part of the bearing disc 8 has five symmetrically distributed "U"-shaped grooves 10, and each "U"-shaped groove has two stop holes 11, and the stop hole diameter is 16 mm. The connecting rod 12 passes through the central positioning hole 9 of the bearing disc to connect the two bearing discs 8 horizontally. Each bearing disc 8 has an arched stop block 13 on the outside. The diameter of the connecting rod 12 matches the arc diameter of the positioning hole 9 and the arched stop block 13. The two arched stop blocks 13 are symmetrically distributed, and the lower ends of the two arched stop blocks 13 are connected to the pillars 7 and connected by welding. The shaft fan 6 is runway-shaped, with a length of 1200mm and an arc diameter of 16mm. There are two limit holes 15 at the upper end, which correspond to the size of the 'U'-shaped groove 10 of the bearing disk 8. There is a runway-shaped hole 16 at the lower end, which is 400mm long and 27mm away from the lower end of the shaft fan. The ten shaft fans 6 correspond to the 'U'-shaped grooves 10 on the two bearing disks 8 respectively. There are five shaft fans on each bearing disk, which are fixed by bolts passing through the 'U'-shaped grooves 10 and the limit holes 15 at the upper end of the shaft fans.

[0062] The core mold 2 is an arched symmetrical structure, each side is composed of sixteen 'Z'-shaped core blocks 17 and a vertical core block 18, connected by a convex core block 19 in the middle, the upper ends of the two vertical core blocks 18 are curved, and are embedded with the lower ends of the 'Z'-shaped core blocks 17. A positioning hole 20 is provided on each core block. The connecting rod 4 passes through the positioning hole 20 and the 'U'-shaped groove 16 on the shaft fan 6 to connect the core mold 2 to the tooling frame 1, and is fixed with a hexagonal nut 21 to complete the combination of the core mold 2 and the tooling frame 1; a small motor 14 is provided on the right side of the bearing 5, so that the ten shaft fans 6 drive the core mold 2 to rotate around the bearing 5 to realize the rotation of the tooling;

[0063] The clamp 3 is composed of two clamps 22 and two small connecting rods 23. Positioning holes 24 are provided at both ends of the clamps 22. The diameter of the positioning holes is 16 mm. During the weaving process, one side of the clamp 22 is close to the core mold 2, and the other side is close to the fabric. The two small connecting rods 23 are connected through the positioning holes 24, and the two clamps 22 are clamped by hexagonal nuts 21, so that the fabric can better fit the core mold 2 to achieve the purpose of contouring.

[0064] Embodiment 2

[0065] A three-dimensional woven composite leaf spring landing gear structure preform includes nine regions, namely, a uniform cross-section region 1 25, a variable cross-section region 1 26, a uniform cross-section region 2 27, a variable cross-section region 2 28, a uniform cross-section region 3 29, a variable cross-section region 3 30, a uniform cross-section region 4 31, a variable cross-section region 4 32, and a uniform cross-section region 5 33. The two sides of the leaf spring are vertical parts, and the middle is an arc part, presenting a symmetrical structure. The fabric thickness of different regions is different. Variable thickness integrated weaving is adopted in the weaving process. The fabric region includes a connecting warp yarn and a weft yarn. The specific parameters of the fabric are set as follows:

[0066] The developed fabric has an arch height of 500mm and a span of 2000mm. The inner length of the entire leaf spring is 2368mm and the width is 185mm. The length of the uniform cross-section area 1 25 is 100mm, the arc length of the variable cross-section area 1 26 is 20mm, the length of the uniform cross-section area 27 is 264mm, the length of the variable cross-section area 28 is 443mm, and the length of the uniform cross-section area 3 29 is 714mm. It has a symmetrical structure. The length of the variable cross-section area 30 is equal to that of the variable cross-section area 28, the length of the uniform cross-section area 4 31 is equal to that of the uniform cross-section area 27, the length of the variable cross-section area 4 32 is equal to that of the variable cross-section area 1 26, and the length of the uniform cross-section area 5 33 is equal to that of the uniform cross-section area 1 25.

[0067] The warp yarn is TG800H-12K carbon fiber three-ply, and the weft yarn is TG800H-12K single-ply;

[0068] The density of the warp yarns is 4 / cm, and the density of the weft yarns is 5 / cm;

[0069] The number of binding warp yarn rows n = fabric width × warp yarn density = 185 / 10 × 4 = 74 rows;

[0070] The volume content of fabric fiber is controlled at about 57%.

[0071] Embodiment 3

[0072] A method for preparing a three-dimensional woven composite material leaf spring landing gear structure preform, wherein the weaving method comprises the following steps:

[0073] S1, tooling preparation, initial yarn arrangement of the fabric, 74 rows of warp yarn, and then weft insertion. According to the thickness of the fabric, the number of weft insertion layers in each area is calculated;

[0074] S2, weaving of equal cross-section area 25:

[0075] S2-1, the fabric in this area is in a vertical shape and the thickness does not change. The fabric thickness is measured to be 25 mm, and the number of warp and weft yarn layers introduced is calculated. At the same time, the weaving tooling is controlled during the weaving process to ensure that the fabric thickness is evenly distributed. The fabric thickness is measured every 20 mm during the weaving process to ensure that its thickness distribution is the same;

[0076] S2-2, further, according to the thickness of the fabric, the number of warp yarn layers introduced is 33 layers, and the number of weft yarn layers is 34 layers. At the same time, during the weaving process, the four hexagonal nuts 21 in the clamp 3 are used to clamp the fabric and the core mold 2 with two clamps 22 to ensure that they are close to the inside of the core mold to achieve the purpose of profiling. After the inner length of the woven landing gear preform reaches 100 mm, it enters the next area for weaving;

[0077] S3, weaving of variable cross-section area 26:

[0078] S3-1, this area is a variable thickness area, which is in the shape of a "corner". The inner length of the fabric is 20mm, and the fabric thickness increases from 25mm to 26mm and then decreases to 20mm. The addition and subtraction of yarn layers during the weaving process are designed to achieve the change of fabric thickness, and the bending shape of the fabric is ensured by controlling the angle of the weaving tooling;

[0079] S3-2, further, when the total inner length of the fabric is 100mm, the yarn is added, the warp yarn is added one layer, becoming 34 layers, the weft yarn is 35 layers, and the fabric thickness reaches 26mm, and then the yarn is reduced, and one layer of outer warp yarn is reduced for each weft, and a total of 8 layers are reduced. At this time, the warp yarn has 26 layers. At the same time, during the weaving process, the motor 14 needs to be used to drive the shaft fan 6 to rotate around the bearing 5 to control the angle of the weaving tooling, so that the cloth mouth is always parallel to the yarn direction. At the same time, the fixture 3 is used to make the fabric fit better with the core mold to achieve profiling molding. When the inner length of the preform reaches 120mm, it enters the next area for weaving;

[0080] S4, weaving of equal cross-sectional area 27:

[0081] S4-1, the fabric thickness in this area does not change. The fabric thickness is still 20mm. The design introduces the number of warp and weft yarn layers. The fabric in this area has a certain curvature. Therefore, tooling is used to ensure the fabric bending surface to achieve profiling. At the same time, the fabric thickness is measured every 20mm during the weaving process to ensure that there is no obvious deviation in the fabric thickness.

[0082] S4-2, further, the number of warp yarn layers is calculated to be 26 layers, the number of weft yarn layers is calculated to be 27 layers, the bearing plate 8 is used to drive the shaft fan 6 to rotate around the bearing 5 by the motor 14 to control the angle of the weaving tooling, and the clamp 3 is used to make the fabric fit tightly to the surface of the core mold 2 to ensure the curved surface of the fabric, and the weaving is 264 mm. At this time, the total length of the inner side of the fabric is 384 mm, and the weaving of the next area is entered;

[0083] S5, weaving of variable cross-section area 28:

[0084] S5-1, the fabric thickness in this area increases evenly, the fabric has a certain curvature, and the thickness increases from 20mm to 37mm. This is achieved by uniformly adding layers of warp yarns. The angle of the weaving tooling is controlled during the weaving process to achieve better shaping of the fabric;

[0085] S5-2, further, the initial number of warp yarn layers of the fabric in this area is 26 layers, and a layer of warp yarn is added on the outside every 26 mm, and a total of 17 layers are added, so that the final fabric thickness reaches 37 mm. At this time, the number of warp yarn layers of the fabric increases to 48 layers. At the same time, during the weaving process, the bearing plate 8 is used to drive the shaft fan 6 to rotate around the bearing 5 to control the angle of the weaving tooling, and the clamp 3 is used to make the fabric fit tightly to the surface of the core mold 2 to ensure the curved surface of the fabric. The weaving is 443 mm. At this time, the total length of the inner side of the fabric is 827 mm, and the next area weaving is entered;

[0086] S6, weaving of equal cross-section area three 29:

[0087] S6-1, this area is the top area of ​​the landing gear, connected to the fuselage. The fabric thickness in this area is 37mm, and the thickness does not change. At the same time, the weaving tooling is controlled during the weaving process to ensure the curvature of the fabric. The fabric thickness is measured every 20mm during the weaving process to ensure that its thickness distribution is equal;

[0088] S6-2, further, according to the thickness calculation, 48 layers of warp yarn and 49 layers of weft yarn are introduced, and no layer of warp and weft yarn is added. At the same time, during the weaving process, the splint 22 and the hexagonal nut 21 are used to make the fabric close to the surface of the core mold 2 to ensure the curvature of the fabric. 714mm is weaved, and the inner length of the fabric reaches 1541mm, and the next area is weaved;

[0089] S7, weaving of variable cross-section area 30:

[0090] S7-1, the variable cross-section area 30 and the variable cross-section area 28 are symmetrically structured, the arc length of this area is 443mm, the fabric thickness is 37mm, the fabric thickness in this area is uniformly thinned from 37mm to 20mm, which is achieved by uniformly reducing the warp yarn layer, and controlling the angle of the weaving tooling to ensure the bending surface of the fabric. At the same time, the fabric thickness is measured every 20mm during the weaving process to ensure that its thickness is within a certain range without large deviations;

[0091] S7-2, further, in the initial stage, the number of warp yarn layers is 48 layers, the number of weft yarn layers is 49 layers, and the number of outer warp yarn layers is reduced by one layer every 26 mm, a total of 17 layers are reduced, and 443 mm is woven. At this time, the fabric thickness is 20 mm, and the number of warp yarn layers is reduced to 26 layers. During the weaving process, the motor 14 is used to drive the shaft fan 6 to rotate around the bearing 5 to control the angle of the weaving tooling. The cloth fell is always parallel to the yarn direction, and the hexagonal nut 21 is used to clamp the two clamps 22, so that the clamp 3 clamps the fabric and the core mold 2 to obtain a certain curved surface. At this time, the total length of the inner side of the fabric reaches 1984 mm, and it enters the next area for weaving;

[0092] S8, weaving of equal cross-section area 4 31:

[0093] S8-1, the equal cross-sectional area 4 31 and the equal cross-sectional area 27 are symmetrically structured. This area is an equal thickness area with a thickness of 20 mm. The thickness is evenly distributed without obvious changes. The thickness of the fabric is measured every 20 mm during the weaving process to ensure that the thickness is evenly distributed. The bending profile of the fabric is ensured by controlling the angle of the weaving tooling.

[0094] S8-2, further, according to the thickness calculation, 26 layers of warp yarn and 27 layers of weft yarn need to be introduced. During the weaving process, the motor 14 is used to drive the shaft fan 6 to rotate around the bearing 5 to control the angle of the weaving tooling, and the clamping plate 22 and the hexagonal nut 21 are used to make the fabric close to the surface of the core mold 2 to ensure the curved surface. The weaving is 264mm. At this time, the total length of the inner side of the fabric reaches 2248mm, and the next stage of weaving is entered;

[0095] S9, weaving of variable cross-section area 432:

[0096] S9-1, the variable cross-section area 4 32 is symmetrical with the variable cross-section area 1 26. This area is a variable thickness area. The fabric thickness increases from 20 mm to 26 mm and then decreases to 25 mm. This is achieved by adding and subtracting layers of warp and weft yarns, and by controlling the angle of the knitting tooling, the contouring is better achieved.

[0097] S9-2, further, continuing the last weft of the previous area, the number of warp yarn layers is 26, and the warp yarn is evenly added. Each weft is woven with a layer of outer warp yarn, and a total of 8 layers are added. At this time, there are 34 layers of warp yarn, and the fabric thickness reaches 26mm. Then the yarn is reduced. The next weft is reduced by one layer of outer warp yarn. There are 33 layers of warp yarn, and the fabric thickness is 25mm. During the weaving process, the motor 14 is used to make the bearing disk 8 drive the shaft fan 6 to rotate around the bearing 5 to control the angle of the weaving tooling, and the fixture 3 is used to make the fabric fit tightly to the surface of the core mold 2 to ensure the curved surface of the fabric. At this time, the total length of the inner side of the fabric is 2268mm, and the next area is entered for weaving;

[0098] S10, weaving of equal cross-section area 533:

[0099] S10-1, the equal cross-section area 5 33 and the equal cross-section area 1 25 are symmetrically structured, which is the vertical area of ​​the landing gear. The thickness of this area does not change. The fabric thickness is 25 mm and the length is 100 mm. No yarn is added or subtracted. The fabric is better fitted to the core mold 2 by controlling the tooling to achieve contour molding;

[0100] S10-2. Further, according to the thickness of the fabric, 33 layers of warp yarns and 34 layers of weft yarns are introduced. During the weaving process, the splint 22 and the hexagonal nut 21 are used to make the fabric close to the surface of the core mold 2 to ensure the curvature of the fabric. The fabric thickness is measured every 20 mm to ensure that there is no obvious deviation in the thickness. After weaving 100 mm, the total length of the inner side of the fabric reaches 2368 mm, and the weaving of the landing gear preform is completed.

[0101] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0102] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A three-dimensional woven composite leaf spring landing gear preform profiling tooling, characterized in that: It comprises a tooling frame (1), a core mold (2), five clamps (3), and five connecting rods (4). The tooling frame (1) comprises a bearing (5), ten shaft fans (6), and two pillars (7). The bearing (5) is provided with two bearing discs (8), a connecting rod (12), two arched stop blocks (13), and a small motor (14). Each bearing disc (8) has a positioning hole (9) at the center. The lower part of the bearing disc (8) has five symmetrically distributed "U"-shaped grooves (10). Each "U"-shaped groove (10) has two stop holes (11). The connecting rod (12) passes through the central positioning hole (9) of the bearing disc (8) to laterally connect the two bearing discs (8). The bearing plates (8) are connected by a plurality of arc-shaped limit blocks (13) on the outside. The lower ends of the two arc-shaped limit blocks (13) are connected to the pillars (7) by welding. The upper ends of the two arc-shaped limit blocks (13) have two limit holes (15) corresponding to the size of the 'U'-shaped groove (10) of the bearing plates (8). The lower ends have runway-shaped holes (16). The ten shaft fans (6) correspond to the 'U'-shaped grooves (10) on the two bearing plates (8). Each bearing plate has five shaft fans (6) which are fixed by bolts passing through the 'U'-shaped grooves (10) and the limit holes (15) on the upper ends of the shaft fans (6); The core mold (2) is an arched symmetrical structure, each side is composed of sixteen 'Z'-shaped core blocks (17) and a vertical core block (18) interlaced and combined, and is connected in the middle by a convex core block (19). The upper ends of the two vertical core blocks (18) are curved and fit with the lower ends of the 'Z'-shaped core blocks (17). Each vertical core block (18) is provided with a positioning hole (20). The connecting rod (4) passes through the positioning hole (20) and the 'U'-shaped groove (16) on the shaft fan (6) to connect the core mold (2) to the tooling frame (1), and is fixed by a hexagonal nut (21). A small motor (14) is provided on the right side of the bearing (5), so that the ten shaft fans (6) drive the core mold (2) to rotate around the bearing (5); The clamp (3) is composed of two clamping plates (22) and two small connecting rods (23). Positioning holes (24) are provided at both ends of the clamping plates (22). During weaving, one side of the clamping plates (22) is close to the core mold (2) and the other side is close to the fabric. The two small connecting rods (23) are connected by passing through the positioning holes (24) and the two clamping plates (22) are clamped by a hexagonal nut (21), so that the fabric can better fit the core mold (2).

2. The three-dimensional woven composite leaf spring landing gear preform profiling tooling according to claim 1 is characterized in that: The diameter of the connecting rod (12) matches the arc diameter of the positioning hole (9) and the arched limiting block (13), and the two arched limiting blocks (13) are symmetrically distributed.

3. The three-dimensional woven composite leaf spring landing gear preform profiling tooling according to claim 1 is characterized in that: The shaft fan (6) is in a runway shape, with a length of 1200 mm and an arc diameter of 16 mm.

4. The three-dimensional woven composite leaf spring landing gear preform copying molding tool according to claim 1, characterized in that: The diameter of the limiting hole (11) is 16 mm.

5. The three-dimensional woven composite leaf spring landing gear preform copying molding tool according to claim 1, characterized in that: The diameter of the positioning hole (9) is 50 mm.

6. A three-dimensional woven composite leaf spring landing gear structure preform prepared by using the three-dimensional woven composite leaf spring landing gear preform copying molding tool as claimed in any one of claims 1 to 6, characterized in that: The leaf spring comprises nine regions, namely, a uniform cross-sectional region 1 (25), a variable cross-sectional region 1 (26), a uniform cross-sectional region 2 (27), a variable cross-sectional region 2 (28), a uniform cross-sectional region 3 (29), a variable cross-sectional region 3 (30), a uniform cross-sectional region 4 (31), a variable cross-sectional region 4 (32), and a uniform cross-sectional region 5 (33). The leaf spring has vertical parts on both sides and a circular arc part in the middle, presenting a symmetrical structure. The fabric thickness of different regions is different. Variable thickness integrated weaving is adopted in the weaving process. The fabric region comprises a connecting warp yarn and a weft yarn. The specific parameters of the fabric are set as follows: The developed fabric has an arch height of 500mm and a span of 2000mm. The inner length of the entire leaf spring is 2368mm and the width is 185mm. The length of the uniform cross-section area 1 25 is 100mm, the arc length of the variable cross-section area 1 26 is 20mm, the length of the uniform cross-section area 27 is 264mm, the length of the variable cross-section area 28 is 443mm, and the length of the uniform cross-section area 3 29 is 714mm. It has a symmetrical structure. The length of the variable cross-section area 30 is equal to that of the variable cross-section area 28, the length of the uniform cross-section area 4 31 is equal to that of the uniform cross-section area 27, the length of the variable cross-section area 4 32 is equal to that of the variable cross-section area 1 26, and the length of the uniform cross-section area 5 33 is equal to that of the uniform cross-section area 1 25. The warp yarn is TG800H-12K carbon fiber three-ply, and the weft yarn is TG800H-12K single-ply; The density of the warp yarns is 4 / cm, and the density of the weft yarns is 5 / cm; The number of binding warp yarn rows n = fabric width × warp yarn density = 185 / 10 × 4 = 74 rows; The volume content of fabric fiber is controlled at about 57%.

7. A method for preparing a three-dimensional woven composite leaf spring landing gear structure preform as claimed in claim 6, characterized in that: The following steps are involved: S1, tooling preparation, initial yarn arrangement of the fabric, 74 rows of warp yarn, and then weft insertion. According to the thickness of the fabric, the number of weft insertion layers in each area is calculated; S2, weaving of uniform cross-section area 1 (25): S2-1, the fabric in this area is in a vertical shape and the thickness does not change. The fabric thickness is measured to be 25 mm, and the number of warp and weft yarn layers introduced is calculated. At the same time, the weaving tooling is controlled during the weaving process to ensure that the fabric thickness is evenly distributed. The fabric thickness is measured every 20 mm during the weaving process to ensure that its thickness distribution is the same; S2-2, further, according to the thickness of the fabric, the number of warp yarn layers introduced is 33 layers, and the number of weft yarn layers is 34 layers. At the same time, during the weaving process, the four hexagonal nuts 21 in the clamp 3 are used to clamp the fabric and the core mold 2 with two clamps 22 to ensure that they are close to the inside of the core mold to achieve the purpose of profiling. After the inner length of the woven landing gear preform reaches 100 mm, it enters the next area for weaving; S3, weaving of variable cross-section zone 1 (26): S3-1, this area is a variable thickness area, which is in the shape of a "corner". The inner length of the fabric is 20mm, and the fabric thickness increases from 25mm to 26mm and then decreases to 20mm. The addition and subtraction of yarn layers during the weaving process are designed to achieve the change of fabric thickness, and the bending shape of the fabric is ensured by controlling the angle of the weaving tooling; S3-2, further, when the total inner length of the fabric is 100mm, the yarn is added, the warp yarn is added one layer, becoming 34 layers, the weft yarn is 35 layers, and the fabric thickness reaches 26mm, and then the yarn is reduced, and one layer of outer warp yarn is reduced for each weft, and a total of 8 layers are reduced. At this time, the warp yarn has 26 layers. At the same time, during the weaving process, the motor 14 needs to be used to drive the shaft fan 6 to rotate around the bearing 5 to control the angle of the weaving tooling, so that the cloth mouth is always parallel to the yarn direction. At the same time, the fixture 3 is used to make the fabric fit better with the core mold to achieve profiling molding. When the inner length of the preform reaches 120mm, it enters the next area for weaving; S4, weaving of uniform cross-section zone 2 (27): S4-1, the fabric thickness in this area does not change. The fabric thickness is still 20mm. The design introduces the number of warp and weft yarn layers. The fabric in this area has a certain curvature. Therefore, tooling is used to ensure the fabric bending surface to achieve profiling. At the same time, the fabric thickness is measured every 20mm during the weaving process to ensure that there is no obvious deviation in the fabric thickness. S4-2, further, the number of warp yarn layers is calculated to be 26 layers, the number of weft yarn layers is calculated to be 27 layers, the bearing plate 8 is used to drive the shaft fan 6 to rotate around the bearing 5 by the motor 14 to control the angle of the weaving tooling, and the clamp 3 is used to make the fabric fit tightly to the surface of the core mold 2 to ensure the curved surface of the fabric, and the weaving is 264 mm. At this time, the total length of the inner side of the fabric is 384 mm, and the weaving of the next area is entered; S5, weaving of variable cross-section area 2 (28): S5-1, the fabric thickness in this area increases evenly, the fabric has a certain curvature, and the thickness increases from 20mm to 37mm. This is achieved by uniformly adding layers of warp yarns. The angle of the weaving tooling is controlled during the weaving process to achieve better shaping of the fabric; S5-2, further, the initial number of warp yarn layers of the fabric in this area is 26 layers, and a layer of warp yarn is added on the outside every 26 mm, and a total of 17 layers are added, so that the final fabric thickness reaches 37 mm. At this time, the number of warp yarn layers of the fabric increases to 48 layers. At the same time, during the weaving process, the bearing plate 8 is used to drive the shaft fan 6 to rotate around the bearing 5 to control the angle of the weaving tooling, and the clamp 3 is used to make the fabric fit tightly to the surface of the core mold 2 to ensure the curved surface of the fabric. The weaving is 443 mm. At this time, the total length of the inner side of the fabric is 827 mm, and the next area weaving is entered; S6, weaving of uniform cross-section zone three (29): S6-1, this area is the top area of ​​the landing gear, connected to the fuselage. The fabric thickness in this area is 37mm, and the thickness does not change. At the same time, the weaving tooling is controlled during the weaving process to ensure the curvature of the fabric. The fabric thickness is measured every 20mm during the weaving process to ensure that its thickness distribution is equal; S6-2, further, according to the thickness calculation, 48 layers of warp yarn and 49 layers of weft yarn are introduced, and no layer of warp and weft yarn is added. At the same time, during the weaving process, the splint 22 and the hexagonal nut 21 are used to make the fabric close to the surface of the core mold 2 to ensure the curvature of the fabric. 714mm is weaved, and the inner length of the fabric reaches 1541mm, and the next area is weaved; S7, weaving of variable cross-section zone three (30): S7-1, the variable cross-section area three (30) is symmetrical with the variable cross-section area two 28. The arc length of this area is 443mm, and the fabric thickness is 37mm. The fabric thickness in this area is uniformly thinned from 37mm to 20mm, which is achieved by uniformly reducing the warp yarn layer and controlling the angle of the weaving tooling to ensure the bending surface of the fabric. At the same time, the fabric thickness is measured every 20mm during the weaving process to ensure that its thickness is within a certain range without large deviations; S7-2, further, in the initial stage, the number of warp yarn layers is 48 layers, the number of weft yarn layers is 49 layers, and the number of outer warp yarn layers is reduced by one layer every 26 mm, a total of 17 layers are reduced, and 443 mm is woven. At this time, the fabric thickness is 20 mm, and the number of warp yarn layers is reduced to 26 layers. During the weaving process, the motor 14 is used to drive the shaft fan 6 to rotate around the bearing 5 to control the angle of the weaving tooling. The cloth fell is always parallel to the yarn direction, and the hexagonal nut 21 is used to clamp the two clamps 22, so that the clamp 3 clamps the fabric and the core mold 2 to obtain a certain curved surface. At this time, the total length of the inner side of the fabric reaches 1984 mm, and it enters the next area for weaving; S8, weaving of uniform cross-section zone four (31): S8-1, the equal cross-sectional area four (31) and the equal cross-sectional area two 27 are symmetrically structured. This area is an equal thickness area with a thickness of 20 mm. The thickness distribution is uniform and there is no obvious change. The thickness of the fabric is measured every 20 mm during the weaving process to ensure that the thickness distribution is uniform. The bending profile of the fabric is ensured by controlling the angle of the weaving tooling. S8-2, further, according to the thickness calculation, 26 layers of warp yarn and 27 layers of weft yarn need to be introduced. During the weaving process, the motor 14 is used to drive the shaft fan 6 to rotate around the bearing 5 to control the angle of the weaving tooling, and the clamping plate 22 and the hexagonal nut 21 are used to make the fabric close to the surface of the core mold 2 to ensure the curved surface. The weaving is 264mm. At this time, the total length of the inner side of the fabric reaches 2248mm, and the next stage of weaving is entered; S9, weaving of variable cross-section zone four (32): S9-1, the variable cross-section area four (32) is symmetrical with the variable cross-section area one 26. This area is a variable thickness area. The fabric thickness increases from 20 mm to 26 mm and then decreases to 25 mm. This is achieved by adding and subtracting layers of warp and weft yarns, and by controlling the angle of the knitting tooling, the contouring molding is better achieved; S9-2, further, continuing the last weft of the previous area, the number of warp yarn layers is 26, and the warp yarn is evenly added. Each weft is woven with a layer of outer warp yarn, and a total of 8 layers are added. At this time, there are 34 layers of warp yarn, and the fabric thickness reaches 26mm. Then the yarn is reduced. The next weft is reduced by one layer of outer warp yarn. There are 33 layers of warp yarn, and the fabric thickness is 25mm. During the weaving process, the motor 14 is used to make the bearing disk 8 drive the shaft fan 6 to rotate around the bearing 5 to control the angle of the weaving tooling, and the fixture 3 is used to make the fabric fit tightly to the surface of the core mold 2 to ensure the curved surface of the fabric. At this time, the total length of the inner side of the fabric is 2268mm, and the next area is entered for weaving; S10, weaving of uniform cross-section zone five (33): S10-1, the equal cross-section area five (33) is symmetrical with the equal cross-section area one 25, and is the vertical area of ​​the landing gear. The thickness of this area does not change. The fabric thickness is 25 mm and the length is 100 mm. No yarn is added or subtracted. The fabric is better fitted to the core mold 2 by controlling the tooling to achieve contour molding; S10-2. Further, according to the thickness of the fabric, 33 layers of warp yarns and 34 layers of weft yarns are introduced. During the weaving process, the splint 22 and the hexagonal nut 21 are used to make the fabric close to the surface of the core mold 2 to ensure the curvature of the fabric. The fabric thickness is measured every 20 mm to ensure that there is no obvious deviation in the thickness. After weaving 100 mm, the total length of the inner side of the fabric reaches 2368 mm, and the weaving of the landing gear preform is completed.

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