An electromagnetic stepping three-dimensional rotary braiding machine and control method

Abstract

The present invention discloses an electromagnetic stepping three-dimensional rotary braiding machine, which includes a braiding machine chassis and its motion mechanism, an electromagnetic auxiliary system, a fabric traction device, and an electronic control system. The motion mechanism of the braiding machine chassis consists of adjacent cross forks, which are used to drive the yarn carrier to move in a certain pattern; the electromagnetic auxiliary system is used to realize the position transfer and stop of the yarn carrier between moving parts; the fabric traction device is used to lift the woven fabric at a certain speed; the electronic control system is used to issue and transmit the motion instructions of the yarn carrier. The present invention also provides a method for preparing three-dimensional structured fabrics by using this machine. The electromagnetic stepping three-dimensional rotary braiding machine described in the present invention innovatively realizes the control of the movement and stop of the yarn carrier through the electromagnetic auxiliary system. The mechanical structure and transmission mode are greatly simplified compared with traditional stepping rotary braiding machines, and it is easy to realize the automation and digital forming of three-dimensional braided fabrics with complex structures.

Description

Technical Field

[0001] The present invention relates to the technical field of knitting machines, and particularly relates to an electromagnetic stepping three-dimensional rotary knitting machine and a control method thereof. Background Art

[0002] Three-dimensional braided fabrics can be used as composite material reinforcements, with stable structures, good designability, and the ability to be integrally near-net shaped. They have been successfully applied in the fields of aerospace, rail transit, automotive and marine, and accordingly, the three-dimensional braiding forming technology and equipment have also been well developed.

[0003] The three-dimensional braiding technology makes a three-dimensional braided preform with a spatial three-dimensional network structure by driving the yarn carriers wound with yarns by a knitting machine to traction the yarns to circulate and interweave. The three-dimensional braided preform can be made by a row type three-dimensional knitting machine and a rotary three-dimensional knitting machine. The rotary three-dimensional knitting machine drives the yarn carriers to circulate and move regularly according to the yarn interweaving rule by the rotation of the chassis moving parts, and can be divided into a continuous rotary knitting machine and a stepping rotary knitting machine.

[0004] The rotary moving parts of the stepping rotary knitting machine have action time sequences, but it can realize the digital control of the moving track of the yarn carriers, and is more suitable for the forming of three-dimensional braided preforms with complex cross-sections. However, at present, the stepping three-dimensional rotary knitting machine used for preparing three-dimensional braided preforms has a high equipment failure rate due to the complex composition structure and the difficult effective control of the collision and interference problems between the moving parts during the operation process, which affects the weaving efficiency and further limits its further popularization and application in the engineering field. Summary of the Invention

[0005] Aiming at the deficiencies in the prior art, the purpose of the present invention is to propose an electromagnetic stepping three-dimensional rotary knitting machine to achieve the efficient forming of three-dimensional braided preforms with complex cross-sections.

[0006] The present invention also provides a control method for the electromagnetic stepping three-dimensional rotary knitting machine.

[0007] To achieve the above purpose, the electromagnetic stepping three-dimensional rotary knitting machine of the present invention can adopt the following technical solutions:

[0008] An electromagnetic stepping three-dimensional rotary braiding machine, comprising an upper support plate, a plurality of cross forks mounted on the support plate, a driving device for driving the cross forks to rotate, and a plurality of yarn carriers cooperating with the cross forks; the plurality of cross forks are uniformly mounted on the upper support plate in rows and columns, and each cross fork includes a central rotating shaft perpendicular to the surface of the upper support plate and inserted into the support plate, and fingers extending in four directions from the central rotating shaft; each finger is an electromagnet structure and is independently controlled to be energized; the driving device is used to drive all the cross forks to rotate simultaneously, and the rotation directions of two adjacent cross forks are opposite; the yarn carrier assembly includes a yarn carrier base and a yarn carrier disposed on the base, and a support column made of ferromagnetic material is provided in the middle of the yarn carrier base for cooperating with the fingers; when the fingers of one of the cross forks are energized, a magnetic force is generated to adsorb the support column and simultaneously drive the yarn carrier base to rotate.

[0009] Further, a plurality of guide grooves are further provided on the upper support plate, and a guide groove is provided between two adjacent cross forks. A guide electromagnet is provided at the bottom of each guide groove. When the fingers of a cross fork are energized and the support column is rotated to face the guide groove, the guide electromagnet is energized to generate a magnetic force greater than that of the fingers to adsorb the support column into the guide groove.

[0010] Further, the driving device includes a motor located below the upper support plate and a plurality of gear shafts arranged in rows and columns and parallel to each other. One gear shaft is coaxially connected to the central rotating shaft of a cross fork, and a gear is provided on each gear shaft. The adjacent two gears in each row or column are meshed with each other, and one of the gear shafts serves as a driving gear shaft and is connected to the output shaft of the motor.

[0011] Further, it further includes a fabric traction device located above the yarn carrier assembly for traction of the yarn wound on the yarn carrier assembly.

[0012] Further, the yarn carrier base further includes an upper mounting block and a lower sliding block. The support column is located between the upper mounting block and the lower sliding block, and the bottom surface of the lower sliding block is in a shape of a boat bottom with a low middle and gradually rising ends for cooperating with the guide groove.

[0013] Further, the support column is cylindrical, and the front end of the finger is an arc-shaped groove adapted to the cylindrical support column.

[0014] Further, it further includes a lower support plate located below the upper support plate. The bottom of the gear shaft is mounted on the lower support plate through a bearing, and a support shaft is provided between the upper support plate and the lower support plate. The bottom of the support shaft is fixed to the lower support plate and the top is fixed to the upper support plate. A through hole is provided at the center of the support shaft for introducing an axial yarn.

[0015] Beneficial effects: Based on the traditional stepping three-dimensional rotary braiding machine, the present invention controls the movement and stop of the yarn carrier through electromagnetic adsorption, and proposes an electromagnetic stepping three-dimensional rotary braiding machine to replace the way of driving the movement of the yarn carrier through the linkage of angle wheels and dials in the traditional stepping three-dimensional rotary braiding machine. The mechanical structure and transmission mode of the electromagnetic stepping three-dimensional rotary braiding machine in the present invention are simplified compared with the traditional stepping three-dimensional rotary braiding machine, reducing the degree of friction and collision between the moving mechanisms and the equipment failure rate, and facilitating the automatic and digital forming of three-dimensional braided fabrics with complex structures.

[0016] The present invention also provides a technical solution for the control method of the above-mentioned electromagnetic stepping three-dimensional rotary braiding machine. An optional technical solution includes the following steps:

[0017] S1. Arrange the yarn carrier assembly on the upper support plate according to the braiding requirements;

[0018] S2. Start the finger electromagnet structure to adsorb the yarn carrier assembly;

[0019] S3. Drive all cross forks to rotate 90° simultaneously;

[0020] S4. The energized finger electromagnet structure in S2 is de-energized, and the finger electromagnet structure of another cross fork adjacent to the de-energized finger is energized, and the yarn carrier assembly slides towards the energized finger;

[0021] S5. Lift the fabric height according to the design requirements of the fabric structure;

[0022] S6. The braiding machine repeats the above mechanical steps to form the fabric structure in a preset trajectory cycle.

[0023] Another optional technical solution for the control method includes the following steps:

[0024] S1. Arrange the yarn carrier assembly on the upper support plate according to the braiding requirements;

[0025] S2. Start one finger electromagnet structure to adsorb the yarn carrier assembly;

[0026] S3. Drive all cross forks to rotate 90° simultaneously;

[0027] S4. Start the electromagnet in the guide groove until the yarn carrier assembly slides into the guide groove from the finger;

[0028] S5. The energized finger electromagnet structure in S2 is de-energized, and the finger electromagnet structure of another cross fork adjacent to the de-energized finger is energized until the yarn carrier assembly slides towards the energized finger;

[0029] S6. Lift the fabric height according to the design requirements of the fabric structure;

[0030] S7. The knitting machine repeats the above mechanical steps to cyclically form a fabric structure along a preset trajectory.

[0031] Further, in step S6, the fabric height is constrained by the following equation:

[0032]

[0033] In the formula, v is the fabric lifting speed of the lifting mechanism (1), H is the fabric pitch height, W is the rotational angular velocity of the cross fork (10), ΔT1 is the time when the finger electromagnet structure is energized to generate magnetic force, and ΔT2 is the time when the electromagnet in the guide groove is energized to generate magnetic force. Description of the Drawings

[0034] Figure 1 It is a schematic overall view of an electromagnetic step three-dimensional rotary knitting machine according to the present invention;

[0035] Figure 2 It is a schematic view of the machine chassis and its motion mechanism of the knitting machine according to the present invention;

[0036] Figure 3 It is a top view of the motion mechanism and electromagnetic auxiliary system of the knitting machine according to the present invention;

[0037] Figure 4 It is an oblique side view of the motion mechanism and electromagnetic auxiliary system of the knitting machine according to the present invention;

[0038] Figure 5 It is a schematic view of the yarn carrier base of the knitting machine according to the present invention;

[0039] Figure 6 It is a schematic view of the yarn carrier base and its yarn carrier of the knitting machine according to the present invention;

[0040] Figure 7 It is a schematic view of the motion of the yarn carrier assembly during the knitting process of the knitting machine according to the present invention, and shows the state where the yarn carrier assembly is adsorbed by the first finger;

[0041] Figure 8 It is a schematic view of the motion of the yarn carrier assembly during the knitting process of the knitting machine according to the present invention, and shows the state where the yarn carrier assembly is driven by the first finger to rotate 90°;

[0042] Figure 9 It is a schematic view of the motion of the yarn carrier assembly during the knitting process of the knitting machine according to the present invention, and shows the state where the yarn carrier assembly is adsorbed by the electromagnet in the guide groove and enters the guide groove;

[0043] Figure 10 It is a schematic view of the motion of the yarn carrier assembly during the knitting process of the knitting machine according to the present invention, and shows the state where the yarn carrier assembly is adsorbed by the second finger adjacent to the first finger;

[0044] Figure 11 For Figures 7 to 10 a three-dimensional schematic diagram integrating the movement of the yarn carrier assembly shown in the same figure;

[0045] Figure 12 It is a schematic diagram of the covered position of the trajectory of the yarn carrier according to the present invention. Specific Embodiments

[0046] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0047] Referring to Figures 1 to 4 as shown, the present invention discloses an electromagnetic stepping three-dimensional rotary braiding machine, including a machine chassis 2 of the braiding machine, a fabric traction device 1, and an electronic control system 3. The fabric traction device 1 is used to lift the woven fabric at a certain speed. The electronic control system 3 is used to issue and transmit the movement instructions of the yarn carrier 5 to realize the digital control of the movement trajectory of the yarn carrier of the braiding machine.

[0048] The structural improvement of the movement control of the yarn carrier 5 on the machine chassis 2 of the braiding machine is the key improvement of the present invention compared with the prior art. The chassis 2 includes an upper support plate 6, a plurality of cross forks 10 installed on the support plate, a driving device for driving the cross forks 10 to rotate, and a plurality of yarn carrier assemblies 23 cooperating with the cross forks 10.

[0049] The plurality of cross forks 10 are uniformly installed on the upper support plate 6 in rows and columns. Each cross fork 10 includes a central rotating shaft 19 perpendicular to the surface of the upper support plate 6 and inserted into the support plate, and finger portions 22 extending from the central rotating shaft 19 in four directions. Each finger portion 22 is an electromagnet structure and is independently controlled to be energized. In this embodiment, the four finger portions 22 on the cross fork 10 extend perpendicular to each other, so the whole is in the shape of a "cross". The driving device is used to drive all the cross forks 10 to rotate simultaneously, and the rotation directions of two adjacent cross forks 10 are opposite. The electromagnet structure is that the finger portions are all made of ferromagnetic materials and are sleeved with energizable solenoids 13.

[0050] The yarn carrier assembly includes a yarn carrier base 14 and a yarn carrier 5 arranged on the base. A support column 18 made of ferromagnetic material is provided in the middle of the yarn carrier base 14 for cooperating with the finger portion 22; when the finger portion 22 of one of the cross forks 10 is energized, a magnetic force is generated to adsorb the support column 18 and drive the yarn carrier base 14 to rotate simultaneously.

[0051] The driving device includes a motor located below the upper support plate 6 and a number of gear shafts arranged in rows and columns and parallel to each other. One gear shaft is coaxially connected to the central rotating shaft 19 of a cross fork 10, and a gear 9 is provided on each gear shaft. The adjacent two gears in each row or column mesh with each other, and one of the gear shafts is used as the driving gear shaft and is connected to the motor output shaft. To support the gear shafts, a lower support plate 7 located below the upper support plate 6 is further included in this embodiment. The bottom of the gear shaft is installed on the lower support plate 7 through a bearing, and a support shaft 8 is provided between the upper support plate and the lower support plate. The bottom of the support shaft 8 is fixed to the lower support plate 7 and the top is fixed to the upper support plate 6. A through hole is provided at the center of the support shaft 8 for introducing the axial yarn.

[0052] As Figure 7 shown, a further improvement is that a number of guide grooves 11 are also provided on the upper support plate 6. A guide groove is provided between every two adjacent cross forks 10. A guide electromagnet 12 is provided at the bottom of each guide groove. When the finger part 22 of a cross fork 10 is energized and rotates the support column 18 to face the guide groove, the guide electromagnet 12 is energized to generate a greater magnetic force relative to the finger part 22 to adsorb the support column 18 into the guide groove. The guide groove 11, as an intermediate structure between two adjacent cross forks 10, can provide positioning and stopping devices for the intermediate trajectory when the yarn carrier assembly moves between two adjacent cross forks 10 to prevent the yarn carrier assembly from running off track. Moreover, a number of guide grooves 11 and the electromagnets 12 between the guide grooves can also be provided at the four edges of the upper surface of the upper support plate 6. When the finger parts 22 of the outermost ring of cross forks 10 rotate the yarn carrier assembly 23 to the four-edge positions of the upper surface of the upper support plate 6, the guide grooves 11 and the electromagnets 12 at the four edges can be used to stop the yarn carrier assembly 23.

[0053] The yarn carrier base 14 further includes an upper mounting block 16 and a lower sliding block 17. The support column 18 is located between the upper mounting block 16 and the lower sliding block 17. The bottom surface of the lower sliding block 17 is in a shape of a boat bottom with a lower middle and gradually rising ends to cooperate with the guide groove 11. The support column 18 is cylindrical, and the front end of the finger part 22 is an arc-shaped groove adapted to the cylindrical support column 18. One or more yarn carriers 5 can be installed on the upper mounting block 16. By increasing or decreasing the number of yarn carriers 5, the increase or decrease of the yarn in the knitting machine can be realized.

[0054] In the case where the guide groove 11 is provided, a control method for preparing a three-dimensional structure fabric by an electromagnetic step three-dimensional rotary knitting machine provided by the present invention is as follows:

[0055] S1. As Figure 7 shown, arrange the yarn carrier assembly at the end of the cross fork 10, start the electromagnet structure of the cross fork finger part 22, supply direct current to the solenoid 13 and continuously increase its current until it tightly adsorbs the yarn carrier assembly 23;

[0056] S2. As shown in Figure 8 , the servo motor 20 mounted on the starting frame is started to drive the moving mechanism to drive the cross fork 10 to rotate synchronously by 90°. At the same time, the yarn carrier assembly 23 also rotates by 90° along with the cross dial;

[0057] S3. As shown in Figure 9 , the electromagnet 12 in the guide groove 11 is started until the yarn carrier assembly 23 slides from the finger part of the cross fork into the guide groove 11;

[0058] S4. As shown in Figure 10 , the electromagnet structure of the cross fork finger part described in step 3 is powered off and the electromagnet structure of the adjacent cross fork finger part is powered on and its current is continuously increased until it tightly adsorbs the yarn carrier assembly 23;

[0059] S5. As shown in Figure 11 , after completing a knitting cycle, the fabric height is increased by the fabric traction mechanism 1 according to the fabric structure design requirements;

[0060] S6. The knitting machine repeats the above mechanical steps to form a fabric structure in a set trajectory cycle. Figure 12 is the range of the trajectory 21 that the yarn carrier assembly can move.

[0061] S7. The knitting machine repeats the above mechanical steps to form a fabric structure in a preset trajectory cycle.

[0062] The power supply system of the electromagnet is controlled by the electronic control system 3 of the knitting machine, and can selectively power on and off any electromagnet structure of the cross fork finger part and the electromagnet 12 between the guide grooves 11 according to the set parameters.

[0063] There is a certain functional relationship between the fabric lifting height in the above steps and the knitting parameters of the knitting machine, and it is restricted by the following equation:

[0064]

[0065] In the formula, v is the fabric lifting speed of the lifting mechanism 1, H is the fabric pitch height, W is the rotational angular velocity of the cross fork 10, ΔT1 is the time for the electromagnet 13 at the four ends of the cross fork to generate magnetic force when powered on, and ΔT2 is the time for the electromagnet 12 in the guide groove to generate magnetic force when powered on.

[0066] For the control method provided for another implementation mode of the knitting machine without a guide groove 11, step S3 of the above control method is deleted, and the yarn carrier assembly can be directly moved from one finger part to an adjacent finger part to achieve knitting control, which will not be elaborated here.

[0067] There are many specific application ways of the present invention, and the above description is only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. An electromagnetic stepping three-dimensional rotary braiding machine, characterized in that, It includes an upper support plate (6), several cross forks (10) mounted on the support plate, a driving device for driving the cross forks (10) to rotate, and several yarn carriers (23) cooperating with the cross forks (10); The several cross forks (10) are evenly mounted on the upper support plate (6) in rows and columns. Each cross fork (10) includes a central rotating shaft (19) perpendicular to the surface of the upper support plate (6) and inserted into the support plate, and finger portions (22) extending from the central rotating shaft (19) in four directions; each finger portion (22) is an electromagnet structure (13) and is independently controlled to be energized; the driving device is used to drive all the cross forks (10) to rotate simultaneously, and the rotation directions of two adjacent cross forks (10) are opposite; The yarn carrier assembly includes a yarn carrier base (14) and a yarn carrier (5) provided on the base. A support column (18) made of ferromagnetic material is provided in the middle of the yarn carrier base (14) for cooperating with the finger portion (22); when the finger portion (22) of one of the cross forks (10) is energized, a magnetic force is generated to adsorb the support column (18) and simultaneously drive the yarn carrier base (14) to rotate.

2. The electromagnetic step three-dimensional rotary braiding machine according to claim 1, wherein: Several guiding grooves (11) are further provided on the upper support plate (6). A guiding groove is provided between two adjacent cross forks (10). A guiding electromagnet (12) is provided at the bottom of each guiding groove. When the finger portion (22) of a cross fork (10) is energized and rotates the support column (18) to face the guiding groove, the guiding electromagnet (12) is energized to generate a magnetic force greater than that of the finger portion (22) to adsorb the support column (18) into the guiding groove.

3. The electromagnetic step three-dimensional rotary braiding machine according to claim 2, characterized in that: The driving device includes a motor located below the upper support plate (6) and several gear shafts arranged in rows and columns and parallel to each other. One gear shaft is coaxially connected to the central rotating shaft (19) of a cross fork (10), and a gear (9) is provided on each gear shaft. The two adjacent gears in each row or column are meshed with each other, and one of the gear shafts serves as a driving gear shaft and is connected to the output shaft of the motor.

4. The electromagnetic step three-dimensional rotary braiding machine according to claim 1 or 2 or 3, characterized in that: It further includes a fabric traction device (1) located above the yarn carrier assembly (5) for traction of the yarn wound on the yarn carrier assembly (5).

5. The electromagnetic step three-dimensional rotary braiding machine according to claim 1 or 2, characterized in that: The yarn carrier base (14) further includes an upper mounting block (16) and a lower sliding block (17). The support column (18) is located between the upper mounting block (16) and the lower sliding block (17). The bottom surface of the lower sliding block (17) is in a shape of a boat bottom that is low in the middle and gradually rises at both ends for cooperating with the guiding groove (11).

6. The electromagnetic step three-dimensional rotary braiding machine according to claim 5, wherein: The support column (18) is cylindrical, and the front end of the finger portion (22) is an arc-shaped groove adapted to the cylindrical support column (18).

7. The electromagnetic step three-dimensional rotary braiding machine according to claim 3, wherein: It further includes a lower support plate (7) located below the upper support plate (6). The bottom of the gear shaft is mounted on the lower support plate (7) through a bearing, and a support shaft (8) is provided between the upper support plate and the lower support plate. The bottom of the support shaft (8) is fixed to the lower support plate (7) and the top is fixed to the upper support plate (6). A through hole is provided at the center of the support shaft (8) for introducing axial yarn.

8. A control method for an electromagnetic step three-dimensional rotary braiding machine according to any one of claims 1 to 7, characterized in that, It includes the following steps: S1. Arrange the yarn carrier assembly on the upper support plate (6) according to the knitting requirements; S2. Activate the electromagnet structure of the finger part (22) to adsorb the yarn carrier assembly; S3. Drive all the cross forks to rotate 90° simultaneously; S4. Cut off the power supply of the energized finger electromagnet structure in S2, and energize the finger electromagnet structure of another cross fork adjacent to the de-energized finger, and the yarn carrier assembly slides towards the energized finger; S5. Lift the fabric height according to the design requirements of the fabric structure; S6. The knitting machine repeats the above mechanical steps to form a fabric structure in a preset trajectory cycle.

9. A control method for an electromagnetic stepping three-dimensional rotary braiding machine according to claim 2, characterized in that Including the following steps: S1. Arrange the yarn carrier assembly on the upper support plate (6) according to the knitting requirements; S2. Activate the electromagnet structure of one finger part (22) to adsorb the yarn carrier assembly; S3. Drive all the cross forks to rotate 90° simultaneously; S4. Activate the electromagnet in the guide groove (11) until the yarn carrier assembly slides from this finger into the guide groove; S5. Cut off the power supply of the energized finger electromagnet structure in S2, and energize the finger electromagnet structure of another cross fork adjacent to the de-energized finger until the yarn carrier assembly slides towards the energized finger; S6. Lift the fabric height according to the design requirements of the fabric structure; S7. The knitting machine repeats the above mechanical steps to form a fabric structure in a preset trajectory cycle.

10. The control method of the electromagnetic step three-dimensional rotary braiding machine according to claim 9, characterized in that, In step S6, the fabric height is restricted by the following equation: In the formula, v is the fabric lifting speed of the lifting mechanism (1), H is the fabric pitch height, W is the rotational angular velocity of the cross fork (10), ΔT1 is the time for the finger electromagnet structure to generate magnetic force when energized, and ΔT2 is the time for the electromagnet in the guide groove to generate magnetic force when energized.

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