Deviation rectifying device for preparing continuous fiber reinforced resin prepreg filaments

Abstract

The invention belongs to the field of composite material additive manufacturing, and discloses a deviation rectifying device for preparing continuous fiber reinforced resin prepreg filaments, which comprises a deviation rectifying module and a tension adjusting module. In order to solve the problem of fiber eccentricity in the prepreg filament caused by a large included angle between the dry filament and a central axis in the continuous fiber prepreg filament preparation process, an unwinding device in which a raw material roller and the dry filament reversely follow up is designed, and it is guaranteed that the included angle between the fiber dry filament and the central axis of the device is smaller than 20 degrees; in order to solve the problem that in the silk making process, due to the fact that tension is too large, fibers are snapped, or due to the fact that the tension is too small, fiber / resin impregnation is insufficient, the tension adjusting device capable of feeding back tension is designed, the tension in the silk making process is quantitatively adjusted, and tension controllability is achieved. Through cooperative work of the deviation rectifying module and the tension adjusting module, the included angle between the dry fiber and the axis of the device is controlled within a small range, meanwhile, quantitative adjustment of the tension of the fiber is achieved, and finally the distribution uniformity and mechanical performance of fibers in the prepared prepreg yarn are improved.

Description

Technical Field

[0001] The invention belongs to the field of composite material additive manufacturing and relates to a deviation-correcting device for preparing continuous fiber-reinforced resin prepreg yarns. Background Art

[0002] Continuous fiber reinforced resin additive manufacturing technology has the advantages of high flexibility and no need for mold manufacturing. In recent years, it has been widely used in the automotive, sporting goods and other industries. Continuous fiber prepreg is an important basic raw material for continuous fiber reinforced resin 3D printing. The degree of fiber / resin impregnation determines the interface bonding performance of the printed component. The uniformity of fiber arrangement in the prepreg determines the smoothness of the printing process. For example, uneven fiber arrangement may cause uneven deposition, clogging, poor interlayer bonding and other problems in the printing process. However, most of the existing continuous fiber prepreg preparations start from the impregnation mold to ensure the degree of fiber / resin impregnation and fiber arrangement uniformity, but do not consider that during the silk making process, the fiber dry filaments on the raw material roller are not always wound around the center of the raw material roller. Therefore, as the silk making process proceeds, the fiber dry filaments on the raw material roller will deviate from the axis at a large angle, which will lead to the problem of fiber eccentricity in the prepared prepreg, and will also make the tension of the silk making process unstable, thereby affecting the degree of fiber / resin impregnation. Therefore, it is necessary to develop a fiber deviation correction device with tension control function to ensure that the angle between the fiber dry yarn and the axis is always in a small range during the silk making process, so as to solve the problems of fiber eccentricity in prepreg yarn and sudden tension change in the silk making process.

[0003] In order to improve the degree of fiber resin / impregnation, patent CN111186138A uses a tensioning roller to increase the pre-tension in the fiber filament preparation process, and increases the external force of the fiber filament when it is impregnated in the flow channel by increasing the tension. However, in the process of pursuing tension increase, the patent ignores that during the silk making process, the dry filaments are not concentrated on the central axis unwinding on the fiber roller, and there is a large deviation between the dry filaments and the impregnation axis, which makes the fiber distribution in the prepared prepreg uneven. Patent CN114179251A improves the fiber dry filament feeding module on the basis of the above patents, and uses a motor to drive the rubber wheel friction to ensure that the fiber filament is in the axis position, but it ignores the strong wear resistance of the fiber. When the dry filaments are rubbed between the rubber wheels for a long time, a gap will be worn in the middle of the rubber wheel, causing the tension adjustment mechanism to be unable to function. Therefore, it is necessary to comprehensively consider the requirements of continuous fiber prepreg performance for tension adjustment and the requirements of fiber filament distribution uniformity for dry filament unwinding tension stability and the angle between the fiber dry filament and the axis, and develop a deviation correction device that can adjust the tension in real time and ensure that the angle between the fiber dry filament and the central axis is small. Summary of the invention

[0004] The present invention discloses a deviation correction device for preparing continuous fiber reinforced resin prepreg yarns, which mainly comprises a raw material roller and a reeling device which moves in opposite directions with the fiber dry yarns. When the fiber dry yarns on the raw material roller deviate upward, they will hit the upper limit switch, and the raw material roller moves downward, and vice versa. By controlling the spacing between the left and right limit switches, the angle between the fiber dry yarns and the central axis is kept in a smaller range, thereby solving the problem of fiber eccentricity in the prepared prepreg yarns. In addition, a tension adjustment device with tension feedback is designed to quantitatively adjust the tension in the yarn making process, thereby solving the problem of fiber yarns being broken due to excessive tension or insufficient fiber / resin impregnation due to too small tension, thereby significantly improving the mechanical properties of the prepreg yarns.

[0005] The technical solution of the present invention:

[0006] A deviation correction device for preparing continuous fiber reinforced thermoplastic resin prepreg yarns, comprising a deviation correction module A and a tension adjustment module B; a raw material roller A9 in the deviation correction module A swings back and forth between two limit switches to achieve a deviation correction function; the tension adjustment module B cooperates with a tension roller through a tension force meter B13 to achieve accurate adjustment of the tension during the preparation of the prepreg yarns.

[0007] The correction module A includes a bracket A1, a linear module A2, a slider A3, a connecting plate A4, an upper positioning block A5, an upper support plate A6, an upper damper A7, an upper support shaft A8, a raw material roller A9, a lower support shaft A10, a motor A11, a lower positioning block A12, a lower support plate A13, a lower damper A14, a base A15, an upper moving block A16, an upper limit switch A17, an upper limit shaft A18, a lower moving block A19, a lower limit switch A20, a lower limit shaft A21 and a bottom plate A22; The linear module A2 is fixed on the bracket A1, the slider A3 is fixed on the linear module A2 and can move up and down, the connecting plate A4 is fixed on the slider A3 to keep the same linear motion as the slider A3; the upper positioning block A5 is fixed on the upper end of the connecting plate A4, and the upper support plate A6 is fixed on the lower end of the upper positioning block A5 to support the raw material roller A9; one end of the upper damper A7 is connected to the upper support plate A6, and the other end is connected to the upper support shaft A8, and the torque of the raw material roller A9 is controlled by adjusting the resistance of the upper damper A7. The upper end of the raw material roller A9 is connected to the upper support shaft A8, and the lower end is connected to the lower support shaft A10; the motor A11 is fixed to the lower end of the linear module A2, and the movement direction of the slider A3 can be adjusted by controlling the rotation direction of the motor A11; the lower positioning block A12 is fixed on the connecting plate A4, and the lower support plate A13 is fixed to the upper end of the lower positioning block A12 to support the raw material roller A9; one end of the lower damper A14 is connected to the lower support plate A13, and the other end is connected to the lower support shaft A10, and the damping of the lower damper A14 can be adjusted by adjusting the damping of the lower damper A14. The torque of the raw material roller A9 is controlled by the force; the base A15 is fixed on the bottom plate A22, the upper moving block A16 is fixed in the upper rectangular groove of the base A15 and can move up and down; the upper limit switch A17 is fixed on the upper moving block A16, and the upper limit shaft A18 is fixed on the upper limit switch A17; the lower moving block A19 is fixed in the lower rectangular groove of the base A15 and can move up and down; the lower limit switch A20 is fixed on the lower moving block A19, and the lower limit shaft A21 is welded on the lower limit switch A20;

[0008] The tension adjustment module B includes an optical axis module B1, a roller bracket B2, a ceramic ring bracket B3, a right ceramic ring B4, a left ceramic ring B5, a first tension roller B6, an upper fixed shaft B7, a screw B8, a second tension roller B9, a lower fixed shaft B10, an optical axis slider B11, a tension sensor bracket B12 and a tension sensor B13; the optical axis module B1 is fixed on the bottom plate A22, the roller bracket B2 is fixed on the right end of the optical axis module B1, the ceramic ring bracket B3 is fixed on the roller bracket B2, the right ceramic ring B4 and the left ceramic ring B5 are connected to each other through the optical axis module B1. The first tension roller B6 is fixed to the front end of the roller bracket B2 by the upper fixed shaft B7, the optical axis slider B11 is installed on the optical axis module B1 through clearance fit, and the screw B8 controls the movement of the optical axis slider B11 by tightening it. The second tension roller B9 is fixed to the front end of the optical axis slider B11 by the lower fixed shaft B10 through threaded connection, the tension sensor bracket B12 is fixed to the base plate A22, and the tension sensor B13 is fixed to the tension sensor bracket B12 by screws, so that the tension change can be tested in real time.

[0009] The raw material roller A9 moves up and down with the rotation of the motor A11. When the raw material roller A9 moves upward, if the dry fiber filaments thereon hit the upper limit shaft A18, it will trigger the designation and feedback to the motor A11, the motor A11 will rotate in the opposite direction, and the raw material roller A9 moves downward; similarly, when the dry fiber filaments hit the lower limit shaft A21 again, it will trigger the instruction feedback to the motor A11 to make the motor A11 rotate in the opposite direction, thereby realizing the upward movement of the raw material roller A9; in this way, it is ensured that the dry fiber filaments are always between the upper limit switch A17 and the lower limit switch A20, thereby ensuring that the dry fiber filaments on the raw material roller A9 maintain a small angle with the axis.

[0010] In the silk-making process, in order to avoid the problem of the dry silk becoming loose during the unwinding process due to the rear-end silk-making drag force being much greater than the damper resistance, and also to avoid the problem of the fiber being stretched and damaged due to the drag force being much smaller than the damper resistance, the drag force F1, the damper resistance F2 and the fiber's own tension F3 need to satisfy the following condition: 0.5F3≤F1-F2≤1.5F3.

[0011] When the fiber dry filaments enter the right ceramic ring B4, there will be a certain angle with the axis of the right ceramic ring B4. Therefore, the inner surface roughness of the right ceramic ring B4 needs to be Ra1.6 to avoid scratching the fiber dry filaments. At the same time, the entrance of the right ceramic ring B4 needs to be made into a bell-shaped mouth to reduce the friction of the fiber dry filaments when entering the right ceramic ring B4; in addition, the lower end of the inner diameter of the right ceramic ring B4 needs to be flush with the upper surface of the first tension roller B6 to ensure that the wire bypasses the first tension roller B6.

[0012] The distance between the upper limit switch A17 and the lower limit switch A20 is adjustable to ensure the constant tension during the silk making process. The distance L1 between the upper limit switch A17 and the lower limit switch A20, the length L2 of the raw material roller A9 and the distance L3 from the center of the raw material roller A9 to any limit switch must meet the following conditions:

[0013]

[0014] The tension sensor B13 has a small force measuring range and is used to accurately measure the change in tension during the silk making process. The second tension roller B9 slides up and down driven by the optical axis slider B11, and adjusts the position of the optical axis slider B11 according to the tension value measured by the tension sensor B13, thereby achieving tension adjustment.

[0015] The beneficial effects of the present invention are as follows: through the coordinated work of the deviation correction module and the tension adjustment module, the problem of tension fluctuation in the silk-making process caused by unstable unwinding of fiber dry silk during the preparation of prepreg silk is improved, and the problem of unstable size and performance of prepreg silk caused by unstable tension is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The present invention is a schematic diagram of the overall structure of a deviation-correcting device for preparing a continuous fiber-reinforced thermoplastic resin prepreg, which is suitable for tension adjustment and deviation correction during the preparation of the continuous fiber-reinforced thermoplastic resin prepreg;

[0017] Figure 2 It is a schematic diagram of a one-view structure of a correction module of a correction device for preparing continuous fiber reinforced thermoplastic resin prepreg yarns of the present invention, which is used for correction of dry yarns in the preparation of prepreg yarns;

[0018] Figure 3 It is a schematic diagram of a tension adjustment module of a deviation correction device for preparing continuous fiber reinforced thermoplastic resin prepreg yarns of the present invention, which is used for deviation correction of dry yarns in the preparation of prepreg yarns;

[0019] Figure 4 It is a schematic diagram of a one-view structure of a correction module of a correction device for preparing continuous fiber reinforced thermoplastic resin prepreg yarns of the present invention, which is used for correction of dry yarns in the preparation of prepreg yarns;

[0020] Figure 5 The arrangement mode and stress condition of dry fiber yarns in a deviation correction device prepared from a continuous fiber reinforced thermoplastic resin prepreg yarn of the present invention;

[0021] Figure 6 A schematic diagram of the distance between a dry fiber and a limit switch in a deviation correction device prepared from a continuous fiber-reinforced thermoplastic resin prepreg according to the present invention;

[0022] In the figure: A correction module, A1 bracket, A2 linear module, A3 slider, A4 connecting plate, A5 upper positioning block, A6 upper support plate, A7 upper damper, A8 upper support shaft, A9 raw material roller, A10 lower support shaft A11 motor, A12 lower positioning block, A13 lower support plate, A14 lower damper, A15 base, A16 upper moving block, A17 upper limit switch, A18 upper limit shaft, A19 lower moving block, A20 lower limit switch, A21 lower limit shaft, A22 bottom plate, B tension adjustment module, B1 optical axis module, B2 roller bracket, B3 ceramic ring bracket, B4 right ceramic ring, B5 left ceramic ring, B6 first tension roller, B7 upper fixed shaft, B8 screw, B9 second tension roller, B10 lower fixed shaft, B11 optical axis slider. DETAILED DESCRIPTION

[0023] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and technical solutions.

[0024] Example 1

[0025] Taking the preparation of continuous fiber reinforced thermoplastic resin prepreg as an example, 1K continuous fiber dry yarn is selected. According to the material properties, appropriate process parameters are selected to carry out this example: the resistance provided by the damper is: F2, and the fiber dry yarn breaking force is: 150N.

[0026] A deviation correction device for continuous fiber prepreg preparation with tension adjustment function, comprising a deviation correction module and a tension adjustment module;

[0027] The correction module A includes a bracket A1, a linear module A2, a slider A3, a connecting plate A4, an upper positioning block A5, an upper support plate A6, an upper damper A7, an upper support shaft A8, a raw material roller A9, a lower support shaft A10, a motor A11, a lower positioning block A12, a lower support plate A13, a lower damper A14, a base A15, an upper moving block A16, an upper limit switch A17, an upper limit shaft A18, a lower moving block A19, and a lower limit switch A20; the linear module A2 is fixed to the bracket A1 by screws. The slider A3 is fixed on the linear module A2 and can move up and down. The connecting plate A4 is fixed on the slider A3 to keep the same linear motion as the slider A3. The upper positioning block A5 is fixed to the upper end of the connecting plate A4 by screws. The upper support plate A6 is fixed to the lower end of the upper positioning block A5 to support the raw material roller A9. One end of the upper damper A7 is connected to the upper support plate A6, and the other end is connected to the upper support shaft A8. The torque of the raw material roller A9 can be controlled by adjusting the resistance of the upper damper A7. The upper end of the raw material roller A9 is connected to the upper support plate A6. The lower end of the lower damper A14 is connected to the lower support shaft A13, and the lower end of the lower damper A14 is connected to the lower support shaft A10. The motor A11 is fixed to the lower end of the linear module A2. The movement direction of the slider A3 can be adjusted by controlling the rotation direction of the motor. The lower positioning block A12 is fixed to the lower end of the connecting plate A4 by screws. The lower support plate A13 is fixed to the upper end of the lower positioning block A12 to support the raw material roller A9. One end of the lower damper A14 is connected to the lower support plate A13, and the other end is connected to the lower support shaft A10. The resistance of the lower damper A14 can be adjusted to achieve the raw material roller A9 torque control, the base A15 is fixed on the bottom plate A22, the upper moving block A16 is fixed in the upper rectangular groove of the base A15 by screws, and can move up and down, the upper limit switch A17 is fixed on the upper moving block A16 by screws, the upper limit shaft A18 is welded on the upper limit switch A17, the lower moving block A19 is fixed in the lower rectangular groove of the base A15 by screws, and can move up and down, the lower limit switch A20 is fixed on the lower moving block A19, and the lower limit shaft A21 is welded on the lower limit switch A20.

[0028] The tension adjustment module B includes an optical axis module B1, a roller bracket B2, a ceramic ring bracket B3, a right ceramic ring B4, a left ceramic ring B5, a first tension roller B6, an upper fixed shaft B7, a screw B8, a second tension roller B9, a lower fixed shaft B10, and an optical axis slider B11; the optical axis module B1 is fixed on the bottom plate A22, the roller bracket B2 is fixed to the right end of the optical axis module B1 by screws, the ceramic ring bracket B3 is fixed to the roller bracket B2, and the right ceramic ring B4 and the left ceramic ring B5 are interference-mounted on both sides of the ceramic ring bracket B3. On the side, the first tension roller B6 is fixed to the front end of the roller bracket B2 by the upper fixed shaft B7 through a threaded connection, the optical axis slider B11 is installed on the optical axis module B1 through clearance fit, and the screw B8 can control the movement of the optical axis slider B11 by loosening or tightening it. The second tension roller B9 is fixed to the front end of the optical axis slider B11 by the lower fixed shaft B10 through a threaded connection, the tension sensor bracket B12 is fixed on the base plate A22, and the tension sensor B13 is fixed to the tension sensor bracket B12 through screws, so that the tension change can be tested in real time.

[0029] First, before the experiment, adjust the two limit switches to an appropriate distance to ensure that the angle between the fiber dry wire at all positions on the raw material roller and the limit axis on the limit switch is less than 10°. Then, the fiber dry wire passes through the two ceramic rings, the upper part of the first tension roller, the lower part of the second tension roller, the upper part of the right wheel of the tension tester, the bottom of the middle wheel of the tension tester, and the upper part of the left wheel of the tension tester in turn. At this time, the dry wire is arranged. After connecting with the subsequent winding device during silk making, the tension can be directly read through the tension sensor, and by comparing the difference between the drag force F3 and the damper resistance F2 and the fiber breaking force, the second tension roller is moved up and down. If: F3-F2<75N, move the second tension roller downward to increase the fiber tension. If: F3-F2>225N, adjust the second tension roller downward to reduce the fiber tension.

[0030] The present invention designs a dry wire roller follow-up unwinding device, so that the fiber dry wire on the dry wire roller always moves between two limit switches, ensuring that the dry wire is always in the axial position during the preparation process, solving the problem of unstable tension in the wire making process; in addition, a tension adjustment device with tension feedback is designed to quantitatively adjust the tension in the wire making process, solving the problem of fiber wire being broken due to excessive tension or insufficient fiber / resin impregnation due to too small tension, thereby significantly improving the mechanical properties of the prepreg.

Claims

1. A deviation-correcting device for preparing continuous fiber-reinforced resin prepreg, characterized in that: The deviation correction device comprises a deviation correction module (A) and a tension adjustment module (B); The correction module (A) comprises a bracket (A1), a linear module (A2), a slider (A3), a connecting plate (A4), an upper positioning block (A5), an upper support plate (A6), an upper damper (A7), an upper support shaft (A8), a raw material roller (A9), a lower support shaft (A10), a motor (A11), a lower positioning block (A12), a lower support plate (A13), a lower damper (A14), a base (A15), an upper moving block (A16), an upper limit switch (A17), an upper limit shaft (A18), a lower moving block (A19), a lower limit switch (A20), and a lower limit shaft (A21 ) and a bottom plate (A22); the linear module (A2) is fixed on the bracket (A1), the slider (A3) is fixed on the linear module (A2) and can move up and down, and the connecting plate (A4) is fixed on the slider (A3) to maintain the same linear motion as the slider (A3); the upper positioning block (A5) is fixed on the upper end of the connecting plate (A4), and the upper support plate (A6) is fixed on the lower end of the upper positioning block (A5) to support the raw material roller (A9); one end of the upper damper (A7) is connected to the upper support plate (A6), and the other end is connected to the upper support shaft (A8), and the raw material roller can be adjusted by adjusting the resistance of the upper damper (A7). (A9) torque control; the upper end of the raw material roller (A9) is connected to the upper support shaft (A8), and the lower end is connected to the lower support shaft (A10); the motor (A11) is fixed to the lower end of the linear module (A2), and the movement direction of the slider (A3) can be adjusted by controlling the rotation direction of the motor (A11); the lower positioning block (A12) is fixed on the connecting plate (A4), and the lower support plate (A13) is fixed on the upper end of the lower positioning block (A12) to support the raw material roller (A9); one end of the lower damper (A14) is connected to the lower support plate (A13), and the other end is connected to the lower support shaft (A10), and the lower damper (A14) is adjusted by adjusting the lower damper ( The torque of the raw material roller (A9) is controlled by adjusting the resistance of the roller (A14); the base (A15) is fixed on the bottom plate (A22); the upper moving block (A16) is fixed in the upper rectangular groove of the base (A15) and can move up and down; the upper limit switch (A17) is fixed on the upper moving block (A16); the upper limit shaft (A18) is fixed on the upper limit switch (A17); the lower moving block (A19) is fixed in the lower rectangular groove of the base (A15) and can move up and down; the lower limit switch (A20) is fixed on the lower moving block (A19); the lower limit shaft (A21) is welded on the lower limit switch (A20); The tension adjustment module (B) comprises an optical axis module (B1), a roller bracket (B2), a ceramic ring bracket (B3), a right ceramic ring (B4), a left ceramic ring (B5), a first tension roller (B6), an upper fixed shaft (B7), a screw (B8), a second tension roller (B9), a lower fixed shaft (B10), an optical axis slider (B11), a tension sensor bracket (B12) and a tension sensor (B13); the optical axis module (B1) is fixed on the bottom plate (A22), the roller bracket (B2) is fixed on the right end of the optical axis module (B1), the ceramic ring bracket (B3) is fixed on the roller bracket (B2), the right ceramic ring (B4) and the left ceramic ring (B5) are fixed on the bottom plate (A22), the optical axis module (B1) is fixed on the bottom plate (A22), the ceramic ring bracket (B3) is fixed on the roller bracket (B2), the right ceramic ring (B4) and the left ceramic ring (B5) are fixed on the bottom plate (A22), the optical axis module (B1) is fixed on the bottom plate (A22), the ceramic ring bracket (B3) is fixed on the right end of the optical axis module (B1 ... right ceramic ring (B4) and the left ceramic ring (B5) The ceramic ring (B5) is interference-fitted on both sides of the ceramic ring bracket (B3); the first tension roller (B6) is fixed to the front end of the roller bracket (B2) by the upper fixed shaft (B7); the optical axis slider (B11) is installed on the optical axis module (B1) through clearance fit; the screw (B8) controls the movement of the optical axis slider (B11) by tightening it; the second tension roller (B9) is fixed to the front end of the optical axis slider (B11) by the lower fixed shaft (B10) through threaded connection; the tension sensor bracket (B12) is fixed to the base plate (A22); the tension sensor (B13) is fixed to the tension sensor bracket (B12) by screws, so that the tension change can be tested in real time.

2. The deviation correction device according to claim 1, characterized in that: The raw material roller (A9) moves up and down as the motor (A11) rotates. When the raw material roller (A9) moves upward, if the dry fiber filaments thereon hit the upper limit shaft (A18), it will trigger the designation and feedback to the motor (A11), the motor (A11) rotates in the opposite direction, and the raw material roller (A9) moves downward. Similarly, when the dry fiber filaments hit the lower limit shaft (A21) again, it will trigger the instruction feedback to the motor (A11) to make the motor (A11) rotate in the opposite direction, thereby realizing the upward movement of the raw material roller (A9). In this way, it is ensured that the dry fiber filaments are always between the upper limit switch (A17) and the lower limit switch (A20), thereby ensuring that the dry fiber filaments on the raw material roller (A9) and the axis maintain a small angle.

3. The deviation correction device according to claim 1, characterized in that: In the silk-making process, in order to avoid the problem of the dry silk becoming loose during the unwinding process due to the rear-end silk-making drag force being much greater than the damper resistance, and also to avoid the problem of the fiber being stretched and damaged due to the drag force being much smaller than the damper resistance, the drag force F1, the damper resistance F2 and the fiber's own tension F3 need to satisfy the following condition: 0.5F3≤F1-F2≤1.5F3.

4. The deviation correction device according to claim 1, characterized in that: When the fiber filaments enter the right ceramic ring (B4), they will have a certain angle with the axis of the right ceramic ring (B4). Therefore, the inner surface roughness of the right ceramic ring (B4) needs to be Ra1.6 to avoid scratching the fiber filaments. At the same time, the entrance of the right ceramic ring (B4) needs to be made into a bell mouth to reduce the friction of the fiber filaments when entering the right ceramic ring (B4); in addition, the lower end of the inner diameter of the right ceramic ring (B4) needs to be flush with the upper surface of the first tension roller (B6) to ensure that the wire material bypasses the first tension roller (B6).

5. The deviation correction device according to claim 1, characterized in that: The distance between the upper limit switch (A17) and the lower limit switch (A20) is adjustable to ensure constant tension during the silk making process. The distance L1 between the upper limit switch (A17) and the lower limit switch (A20), the length L2 of the raw material roller (A9) and the distance L3 from the center of the raw material roller (A9) to any limit switch must satisfy the following conditions:

6. The deviation correcting device according to claim 1, characterized in that: The tension sensor (B13) has a small force measuring range and is used to accurately measure the change in tension during the silk making process. The second tension roller (B9) slides up and down under the drive of the optical axis slider (B11), and adjusts the position of the optical axis slider (B11) according to the tension value measured by the tension sensor (B13), thereby realizing tension adjustment.

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