Weaving forming method of high-thickness rotating body

Abstract

The invention discloses a knitting forming method of a rotating body, including: determining the knitting parameters of the rotating body according to the technical requirements of the rotating body; dividing the rotating body into a plurality of concentric circle areas in the thickness direction; calculating the number of yarn columns and layers in each concentric circle area, and the difference in the number of columns in adjacent concentric circle areas is 2n; determining the number of knitting machines according to the number of yarn columns in each concentric circle area, and evenly arranging the knitting machines along the circumferential direction of the rotating body; evenly distributing the number of yarn columns in each concentric circle area on each knitting machine, and the yarns on the yarn carrier of each knitting machine are distributed in a stepped manner, breaking through the problem of the inability to fit the mold due to the unchanged number of radial yarn columns of the traditional three-dimensional knitting rotating body; knitting according to the knitting process to obtain the rotating body. Suitable for rotating body components with an inner and outer diameter difference ratio of ≥2.5 times; using three-dimensional knitting process technology to achieve the overall knitting of high-thick rotating bodies, improving the mechanical properties between layers of the preform.

Description

Technical Field

[0001] The invention belongs to the technical field of textile technology and relates to a weaving forming method for a high-thickness rotating body. Background Art

[0002] High-performance fiber preform reinforced composite materials are highly favored by the aerospace and defense fields due to their excellent properties such as light structure weight, anti-delamination, high strength, ablation resistance, and high damage tolerance. High-thickness rotating bodies are a common component in the aerospace and defense fields, such as engine throat liners, nozzles, protective sleeves, etc. These components are often required to have properties such as high temperature resistance, high strength, erosion resistance, non-delamination, and good air tightness. High-performance fiber three-dimensional braids have properties such as anti-delamination, ablation resistance, and high damage tolerance due to their special structure, highlighting its application advantages. For high-thickness rotating bodies, a two-dimensional lamination method is usually used for preparation. The preform is woven on a loom and continuously wound on the rotating body core mold to obtain a high-thickness rotating body. This method has the disadvantage of poor interlayer performance due to the lack of reinforcing fibers in the thickness direction. In addition, this method is not integrally formed, and seams will be formed on the surface of the rotating body.

[0003] Regarding the high-thickness rotor weaving forming method, the preparation method disclosed in patent CN112877862A "Method for preparing rotor preform and rotor preparation method" is to divide the rotor into several rotating bodies, prepare corresponding winding shafts, arrange the warp yarns along the main body, interweave with the weft yarns through rotation, and determine the number of rotation windings according to the thickness to prepare the rotor preform. Patent CN108004650B "Large-size variable-thickness rotor preform and preparation method thereof" discloses a variable-thickness rotor preparation method, which determines the size parameters of the variable-thickness rotor preform based on the size parameters of the variable-thickness rotor preform, weaves the variable-thickness preform on a loom, and then continuously winds the variable-thickness preform on the rotor core mold to obtain the variable-thickness rotor preform. The methods used in the two patents to achieve high-thickness rotating bodies are to stack multiple layers of woven two-dimensional fabrics and wind them on the rotating body core mold to form a high-thickness rotating body. Adjacent layers of fabric are simply stacked together, and there is no fiber connection in the thickness direction. The interlayer performance is weak and easy to delaminate, which is suitable for structural parts that do not require high interlayer performance. In addition, the traditional three-dimensional woven rotating body has the limitation of unchanged radial yarn columns. For rotating components with thicker thickness, the inner diameter and outer diameter have a large difference. If the number of radial yarn columns remains unchanged, it will cause the internal yarn to be too crowded to fit the mold or the external yarn to be too sparse and not dense. Summary of the invention

[0004] The purpose of the present invention is to provide a weaving forming method for a high-thickness rotating body, which solves the problem in the prior art that the number of radial yarn columns remains unchanged, resulting in the internal yarns being too crowded to fit the mold and the external yarns being too sparse and not dense.

[0005] The technical solution adopted by the present invention is a method for knitting a high-thickness rotating body, comprising the following steps:

[0006] Step 1: Determine the knitting parameters of the high-thickness rotating body according to the technical requirements of the high-thickness rotating body;

[0007] Step 2, dividing the high-thick rotating body into a number of concentric circle areas along the thickness direction;

[0008] Step 3, according to the weaving parameters of the high-thickness rotating body and the size of the concentric circle area, the number of yarn columns and the number of layers in each concentric circle area are calculated, and the difference in the number of columns in adjacent concentric circle areas is 2n;

[0009] Step 4: Determine the number of knitting machines according to the number of yarn columns in each concentric circle area, and evenly arrange the knitting machines along the circumferential direction of the rotating body; evenly distribute the number of yarn columns in each concentric circle area on each knitting machine, and the yarn on the yarn carrier of each knitting machine is distributed in a stepped manner;

[0010] Step 5: Weave according to the weaving process to obtain a rotating body.

[0011] The present invention is also characterized in that:

[0012] The difference ratio between the inner and outer diameters of the high-thick rotating body is greater than or equal to 2.5 times.

[0013] The number of knitting machines is the greatest common divisor of the number of columns in each concentric circle area.

[0014] The weaving process is a three-dimensional four-step process. In the three-dimensional four-step weaving process, after every two steps, the yarn is shifted and replaced between adjacent weaving machines, and every four steps constitutes a weaving cycle.

[0015] The yarn shifting and transposition process in the three-dimensional four-step method is as follows: between adjacent knitting machines, the yarn shifting and transposition are performed alternately left and right by row to restore the yarn arrangement to the initial state.

[0016] The weaving process is 2.5D weaving process, and the specific operation steps are:

[0017] Step 5.1, first move the yarn carriers of the odd-numbered or even-numbered rows on each braiding machine radially by the distance between two yarn carriers to form a cloth fell; introduce circumferential yarns into each layer of cloth fell from the inside to the outside in turn, interweave with the braiding yarn, complete half an interweaving cycle, and then restore the yarn carriers to their initial flush state;

[0018] Step 5.2, move the yarn carrier that has not been moved in step 5.1 radially by the distance of two yarn carriers, and the moving direction is the same as step 5.1, to form a cloth fell again; introduce circumferential yarn into each layer of cloth fell from the outside to the inside in turn, and interweave with the braiding yarn to complete the entire interweaving cycle, and then restore the yarn carrier to the initial state;

[0019] Step 5.3: Repeat steps 5.1-5.2 until the knitting of the rotating body is completed.

[0020] The weaving process is 2.5D three-way orthogonal weaving process. The specific operation steps are as follows:

[0021] Step 5.1, separate the braided yarns from inside to outside in rows along the circumferential direction to form a cloth fell, introduce the circumferential yarns in sequence, and then introduce the normal yarns in sequence from inside to outside or from outside to inside in the column direction to form interlacing;

[0022] Step 5.2, continue to separate the braided yarns by rows, introduce the circumferential yarns in sequence along the circumferential direction, and then introduce the normal yarns by columns in the opposite direction to step 5.1 to complete a cycle of interweaving;

[0023] Step 5.3: Repeat steps 5.1-5.2 until the knitting of the rotating body is completed.

[0024] The beneficial effects of the present invention are as follows: the weaving forming method of the high-thickness rotating body of the present invention is suitable for rotating body components with thick thickness and inner and outer diameter difference ratio ≥2.5 times; the yarns are arranged in a stepped manner in equally divided areas, which breaks through the problem of the inability to fit the mold or the external yarns being too sparse and not dense due to the unchanged number of radial yarn columns of the traditional three-dimensional weaving rotating body; the three-dimensional weaving process technology is used to realize the overall weaving of the high-thickness rotating body, which greatly improves the mechanical properties between the layers of the preform. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram of a rotating body in the weaving forming method of a high-thick rotating body of the present invention;

[0026] Figure 2 It is a top view of the rotating body after being equally divided in the weaving forming method of the high-thick rotating body of the present invention;

[0027] Figure 3 It is a schematic diagram of the arrangement of the braiding machines in the braiding forming method of the high-thickness rotating body of the present invention;

[0028] Figure 4 It is a schematic diagram of the stepped yarn arrangement in the weaving forming method of the high-thickness rotating body of the present invention;

[0029] Figure 5 This is a diagram showing the initial state of yarn arrangement before weaving in the weaving forming method of a high-thickness rotating body of the present invention;

[0030] Figure 6 It is a state diagram of the yarn carrier after two steps of movement in the knitting forming method of the high-thickness rotary body of the present invention;

[0031] Figure 7 It is a schematic diagram of the yarn position after the first yarn shifting and transposition in the knitting forming method of the high-thickness rotary body of the present invention;

[0032] Figure 8 It is a state diagram of the yarn carrier after four steps of movement in the knitting forming method of the high-thickness rotary body of the present invention;

[0033] Fig. 9 It is a schematic diagram of the yarn position after the second yarn shifting and transposition in the knitting forming method of the high-thickness rotary body of the present invention;

[0034] Fig.10 It is a schematic structural diagram of another rotating body in the weaving forming method of a high-thick rotating body of the present invention;

[0035] Fig.11 It is a schematic diagram of the 2.5D weaving process of a rotating body in the weaving forming method of a high-thick rotating body of the present invention. DETAILED DESCRIPTION

[0036] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] The braiding forming method of a high-thickness rotating body is applicable to a rotating body whose inner and outer diameters differ in a ratio greater than or equal to 2.5 times, and comprises the following steps:

[0038] Step 1: Determine the weaving parameters of the high-thickness rotating body according to the technical requirements of the high-thickness rotating body; the weaving parameters include the size and shape of the rotating body, the fiber volume fraction, the height of the flower knot, and the width of the flower knot;

[0039] Step 2: In order to make the preform fit the mold better and the yarn distribution more even, the high-thick rotating body is equally divided into several concentric circle areas along the thickness direction;

[0040] Step 3: Calculate the number of yarn columns in each concentric circle area according to the diameter of each concentric circle area of ​​the high-thick rotating body and the width of the flower knot, and the difference in the number of columns in adjacent concentric circle areas is 2n; calculate the number of yarn layers in each concentric circle area according to the fiber volume fraction and the flower knot height;

[0041] Step 4: The greatest common divisor of the number of yarn columns in the concentric circle areas is used as the number of knitting machines, and the knitting machines are evenly arranged along the circumferential direction of the rotating body; the number of yarn columns in each concentric circle area is evenly distributed on each knitting machine, and the yarns on the yarn carrier of each knitting machine are distributed in a stepped manner;

[0042] Step 5: Weave according to the weaving process to obtain a rotating body.

[0043] Step 5.1, first move the odd-numbered row (2n+1) yarn carrier upward by the distance of one yarn carrier, and then the yarn arrangement is in the initial state before weaving;

[0044] Step 5.2, the yarn carriers in the odd-numbered columns (2n+1) move upward by the distance of one yarn carrier, and the yarn carriers in the even-numbered columns (2n) move downward by the distance of one yarn carrier;

[0045] Step 5.3, the yarn carriers of the odd-numbered rows (2n+1) move to the left by the distance of one yarn carrier, and the yarn carriers of the even-numbered rows (2n) move to the right by the distance of one yarn carrier;

[0046] Step 5.4, between adjacent knitting machines, perform yarn shifting and repositioning operations alternately in rows;

[0047] Step 5.5: The movement direction is opposite to that of step 5.2;

[0048] Step 5.6: The direction of movement is opposite to that of step 5.3. At this time, the yarn movement state is as follows: Fig. 9 As shown;

[0049] Step 5.7, between adjacent knitting machines, the second yarn shifting and replacement is completed row by row, and the yarn movement direction is opposite to the first time, so that the yarn arrangement is restored to the initial state; thus completing a knitting cycle;

[0050] Step 6: After weaving a cycle, every two rows are grouped together for arrangement and tightening, so that the yarns are interwoven with each other. Repeat 5.2-5.7, and with the corresponding tightening operation, the braided yarns can be interwoven with each other to obtain a high-thickness rotating body.

[0051] The weaving process is 2.5D weaving process, and the specific operation steps are:

[0052] Step 5.1, first move the yarn carriers of the odd-numbered or even-numbered rows on each braiding machine radially by the distance between two yarn carriers to form a cloth fell; introduce circumferential yarns into each layer of cloth fell from the inside to the outside in turn, interweave with the braiding yarn, complete half an interweaving cycle, and then restore the yarn carriers to their initial flush state;

[0053] Step 5.2, move the yarn carrier that has not been moved in step 5.1 radially by the distance of two yarn carriers, and the moving direction is the same as step 5.1, to form a cloth fell again; introduce circumferential yarn into each layer of cloth fell from the outside to the inside in turn, and interweave with the braiding yarn to complete the entire interweaving cycle, and then restore the yarn carrier to the initial state;

[0054] Step 5.3: Repeat steps 5.1-5.2 until the knitting of the rotating body is completed.

[0055] The weaving process is 2.5D three-way orthogonal weaving process. The specific operation steps are as follows:

[0056] Step 5.1, separate the braided yarns from inside to outside in rows along the circumferential direction to form a cloth fell, introduce the circumferential yarns in sequence, and then introduce the normal yarns in sequence from inside to outside or from outside to inside in the column direction to form interlacing;

[0057] Step 5.2, continue to separate the braided yarns by rows, introduce the circumferential yarns in sequence along the circumferential direction, and then introduce the normal yarns by columns in the opposite direction to step 5.1 to complete a cycle of interweaving;

[0058] Step 5.3: Repeat steps 5.1-5.2 until the knitting of the rotating body is completed.

[0059] Through the above methods, the weaving forming method of the high-thickness rotating body of the present invention is suitable for rotating body components with thick thickness and inner and outer diameter difference ratio ≥ 2.5 times; the use of equally divided area stepped arrangement of yarns breaks through the problem of the inability to fit the mold due to the unchanged number of radial yarn columns of the traditional three-dimensional braided rotating body; the three-dimensional braiding process technology is used to achieve the overall weaving of the high-thickness rotating body, which greatly improves the mechanical properties between the layers of the preform.

[0060] Example 1

[0061] Step 1: Figure 1 As shown, the thick cylindrical rotating body has an inner diameter of 10mm, an outer diameter of 30mm and a height of 20cm. The raw material is 6K carbon fiber, the fiber volume fraction is 45%, and a three-dimensional braided structure is adopted. The designed braided flower node height is 4.5mm and the flower node width is 1.5mm.

[0062] Step 2: Divide the rotating body into three concentric circle areas along the thickness direction, marked as area 1, area 2, and area 3. Figure 2 As shown, the diameters of area 1, area 2, and area 3 are Φ116.67 mm, Φ223.33 mm, and Φ330 mm, respectively;

[0063] Step 3, according to the diameter of each concentric circle area of ​​the rotating body and the width of the flower node, the number of yarn columns in area 1, area 2, and area 3 are calculated to be 69.82, 97.96, and 125.66 respectively. Since the number of yarn columns in each concentric circle area must be an even number, the number of yarn columns in each concentric circle area is taken as: 70 columns, 98 columns, and 126 columns respectively; according to the fiber volume fraction and the flower node height, the number of layers in area 1, area 2, and area 3 are all 2 layers;

[0064] Step 4: The greatest common divisor of the number of yarn rows in area 1, area 2, and area 3 is 7. Set up 7 knitting devices, such as Figure 3As shown, the braiding machines are evenly arranged along the circumferential direction of the rotating body; the number of yarn columns in each concentric circle area is evenly distributed on each braiding machine, that is, on each device, area 1 is 10 columns, area 2 is 14 columns, and area 3 is 18 columns. The yarn on each braiding machine is tied to the braiding machine yarn carrier in a ladder shape, as shown in FIG. Figure 4 As shown;

[0065] Step 5, weaving using a three-dimensional four-step weaving process;

[0066] Step 5.1, first move the odd-numbered row (2n+1) yarn carrier upward by the distance of one yarn carrier. At this time, the yarn arrangement is the initial state before weaving. The yarn arrangement is as follows: Figure 5 As shown;

[0067] Step 5.2, the yarn carriers in the odd-numbered columns (2n+1) move upward by the distance of one yarn carrier, and the yarn carriers in the even-numbered columns (2n) move downward by the distance of one yarn carrier; the yarn carriers in the odd-numbered rows (2n+1) move left by the distance of one yarn carrier, and the yarn carriers in the even-numbered rows (2n) move right by the distance of one yarn carrier; at this time, the movement state of the yarn on each knitting machine is as follows: Figure 6 As shown;

[0068] Step 5.3: Between adjacent knitting machines, perform the yarn shifting and transposition operation alternately in rows, completing the first yarn shifting and transposition. At this time, the yarn arrangement state is as follows: Figure 7 shown.

[0069] Step 5.4, the yarn carriers in the odd-numbered columns (2n+1) move downward by the distance of one yarn carrier, and the yarn carriers in the even-numbered columns (2n) move upward by the distance of one yarn carrier; the yarn carriers in the odd-numbered rows (2n+1) move right by the distance of one yarn carrier, and the yarn carriers in the even-numbered rows (2n) move left by the distance of one yarn carrier; at this time, the yarn movement state is as follows: Figure 8 As shown;

[0070] Step 5.5: In the opposite direction of the first yarn shifting, the yarn is shifted to the adjacent weaving equipment alternately left and right, and the weaving yarn is arranged as follows: Fig. 9 As shown, the second shifting and yarn changing is completed, thereby completing a knitting cycle;

[0071] Step 6: After weaving a cycle, every two rows are grouped together for arrangement and tightening, so that the yarns are interwoven with each other. Repeat 5.2-5.5, and with the corresponding tightening operation, the braided yarns can be interwoven with each other to obtain a high-thickness rotating body.

[0072] Example 2

[0073] like Fig.10As shown, it is an irregular rotary preform, the inner diameter of the upper half 1 of the rotary preform is Φ30mm~Φ40mm, the corresponding outer diameter is Φ55mm~Φ70mm, the difference ratio between the inner and outer diameters is less than 2.5, and radial equal row yarn is directly adopted. The inner diameter of the thinnest part in the middle of the lower half 2 is Φ11mm, the outer diameter is Φ31mm, and the difference ratio between the inner and outer diameters is 2.9, which is suitable for the high-thick rotary body weaving forming method of the present invention.

[0074] Step 1, the rotary preform raw material adopts 6K carbon fiber, the fiber volume fraction is 45%, and a 2.5D shallow cross-bend structure is adopted, the warp density is 10±0.2 strands / cm, and the weft density is 6±0.2 strands / cm;

[0075] Step 2: Divide the rotating body into three concentric circle areas along the thickness direction;

[0076] Step 3, along the radial direction from inside to outside, the yarns in area 1 are arranged into 18 rows × 7 layers, the yarns in area 2 are arranged into 24 rows × 7 layers, and the yarns in area 3 are arranged into 30 rows × 7 layers;

[0077] Step 4: Weave from the large end to the small end, evenly arrange the starting yarn rows on the three machines along the circumferential direction, and weave according to the 2.5D shallow cross bend weaving method, such as Fig.11 As shown;

[0078] Step 5.1, first move the odd-numbered yarn carriers on each device radially by the distance of two yarn carriers to form a weaving fell; introduce the circumferential yarn from the inside to the outside in turn along the circumferential direction, interweave with the braiding yarn, complete half an interweaving cycle, and then restore the yarn carrier to the initial flush state;

[0079] Step 5.2, move the yarn carriers in the even-numbered columns radially by the distance of two yarn carriers to form the weaving fell again; introduce the circumferential yarns from the outside to the inside in order along the circumferential direction by row, interweave with the braiding yarns to complete the entire interweaving cycle, and then restore the yarn carriers to the initial state, at which time a braiding cycle is completed;

[0080] Step 5.3, arrange the braiding yarn, and repeat steps 5.1-5.2 until the preform is braided.

Claims

1. A method for knitting a high-thickness rotating body, characterized in that: The following steps are involved: Step 1: Determine the knitting parameters of the high-thickness rotating body according to the technical requirements of the high-thickness rotating body; The difference between the inner and outer diameters of the high-thick rotating body is greater than or equal to 2.5 times; Step 2, dividing the high-thick rotating body into a number of concentric circle areas along the thickness direction; Step 3, according to the weaving parameters of the high-thickness rotating body and the size of the concentric circle area, the number of yarn columns and the number of layers in each concentric circle area are calculated, and the difference in the number of columns in adjacent concentric circle areas is 2n; Step 4: Determine the number of knitting machines according to the number of yarn columns in each concentric circle area, and evenly arrange the knitting machines along the circumferential direction of the high-thickness rotating body; evenly distribute the number of yarn columns in each concentric circle area on each knitting machine, and the yarn on the yarn carrier of each knitting machine is distributed in a stepped manner; The number of knitting machines is the greatest common divisor of the number of columns in each concentric circle area; Step 5: Weave according to the weaving process to obtain a high-thick rotating body.

2. The method for knitting a high-thickness rotating body according to claim 1, characterized in that: The weaving process is a three-dimensional four-step process. In the three-dimensional four-step process, after every two steps of movement, the yarn is shifted and replaced between adjacent weaving machines, and every four steps constitute a weaving cycle.

3. The method for knitting a high-thickness rotating body according to claim 2, characterized in that: The yarn shifting and repositioning process in the three-dimensional four-step method is as follows: between adjacent knitting machines, the yarn shifting operation is performed alternately left and right by row, so that the yarn arrangement is restored to the initial state.

4. The method for knitting a high-thickness rotating body according to claim 1, characterized in that: The weaving process is a 2.5D weaving process, and the specific operation steps are: Step 5.1, first move the yarn carriers of the odd-numbered or even-numbered rows on each braiding machine radially by the distance between two yarn carriers to form a cloth fell; introduce circumferential yarns into each layer of cloth fell from the inside to the outside in turn, interweave with the braiding yarn, complete half an interweaving cycle, and then restore the yarn carriers to their initial flush state; Step 5.2, move the yarn carrier that has not been moved in step 5.1 radially by the distance of two yarn carriers, and the moving direction is the same as step 5.1, to form a cloth fell again; introduce circumferential yarn into each layer of cloth fell from the outside to the inside in turn, and interweave with the braiding yarn to complete the entire interweaving cycle, and then restore the yarn carrier to the initial state; Step 5.3: Repeat steps 5.1-5.2 until the weaving of the high-thick rotating body is completed.

5. The method for knitting a high-thickness rotating body according to claim 1, characterized in that: The weaving process is a three-way orthogonal weaving process, and the specific operation steps are as follows: Step 5.1, separate the braided yarns from inside to outside in rows along the circumferential direction to form a cloth fell, introduce the circumferential yarns in sequence, and then introduce the normal yarns in sequence from inside to outside or from outside to inside in the column direction to form interlacing; Step 5.2, continue to separate the braided yarns by rows, introduce the circumferential yarns in sequence along the circumferential direction, and then introduce the normal yarns by columns in the opposite direction to step 5.1 to complete a cycle of interweaving; Step 5.3: Repeat steps 5.1-5.2 until the weaving of the high-thick rotating body is completed.

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