Constant tension control yarn unwinding device and creel

Abstract

This application relates to the technical field of yarn tension control, and discloses a constant tension control yarn unwinding device and a yarn unwinding frame, including a structural support base, a support fixture, an unwinding shaft, a rotational drag-reducing support, and a rotational drag control assembly. The unwinding shaft is rotatably connected to the structural support base through the rotational drag-reducing support. The support fixture is sleeved and fixedly connected to the unwinding shaft. The rotational drag control assembly is fixedly connected to the structural support base. The unwinding shaft abuts against the rotational drag control assembly. The structural support base is provided with a friction control hole. A friction part is provided at a position opposite to the friction control hole on the unwinding shaft. The friction part and the friction control hole are clearance-fitted. The rotational drag control assembly includes a shaft end limiter rotatably connected to the end of the unwinding shaft away from the support fixture, and a pressure regulator with one end connected to the structural support base and the other end connected to the shaft end limiter to adjust the contact pressure between the friction part and the friction control hole. This application achieves the effect of improving the tension stability of the yarn bobbin during the unwinding process.

Description

Technical Field

[0001] This application relates to the technical field of yarn tension control, and in particular to a constant tension control yarn unwinding device and a yarn unwinding frame. Background Technology

[0002] In the production process of carbon fiber / glass fiber products, the tension stability of yarn is crucial. If the yarn tension is inconsistent on different yarn bobbins or the yarn tension on the same yarn bobbin is inconsistent at different times, it will affect the appearance and performance of the yarn prepreg or the woven fabric. Therefore, it is necessary to improve the stability of yarn tension through unwinding tension control technology.

[0003] Currently, the carbon fiber / glass fiber production industry mainly uses traditional yarn unwinding tension control technology, which mostly employs purely mechanical methods such as damping belts, springs, or limiting weights to apply tension to the yarn. For example, the tension of the yarn unwinding on the entire yarn frame can be uniformly controlled by adjusting the locking device on the damping belt and the tension adjustment linkage on the yarn frame separately. This type of solution is low in cost and simple in structure, but its disadvantages are: the spring stroke is small, resulting in a limited adjustment range; the fuzz accumulated in the yarn carrier and mechanical jamming can cause inconsistent spring compensation lengths; the weight of the yarn bobbin will gradually decrease during use, and the spring cannot be adjusted in real time, ultimately leading to unstable tension.

[0004] In recent years, more advanced active / closed-loop tension control technologies have emerged. For example, non-contact tension stabilization control methods based on sensor detection maintain stable and controllable yarn tension. Closed-loop control systems precisely regulate motor speed and tension through real-time feedback and dynamic parameter adjustment, using methods such as PID algorithms and fuzzy logic control. The constant tension yarn feeder (KTF) uses fully digital technology to achieve dual control of tension and speed. Although the above active control schemes have significantly improved tension stability, they still have the following shortcomings: First, most schemes are not adaptable enough to the differences in the properties of carbon fiber and glass fiber. Carbon fiber is brittle and easily damaged, while glass fiber has a smooth surface and is prone to slippage; a single control strategy cannot take both into account. Second, existing active control devices are complex in structure, expensive, and require a large installation space, limiting their promotion in actual continuous large-scale production.

[0005] Therefore, regarding the aforementioned related technologies, the inventors believe that the existing technologies have the problem that the unwinding tension stability control is difficult to meet the high requirements of carbon fiber / glass fiber prepreg and woven fabric production. Summary of the Invention

[0006] In order to improve the yarn tension stability during the unwinding process of the yarn bobbin, this application provides a constant tension control yarn unwinding device and a yarn feeding frame.

[0007] The first objective of this invention is achieved by the following technical solution: A constant tension controlled yarn unwinding device includes a structural support base, a support fixture, an unwinding shaft, a rotational drag-reducing support, and a rotational drag control assembly. The unwinding shaft is rotatably connected to the structural support base via the rotational drag-reducing support. The support fixture is sleeved and fixedly connected to the unwinding shaft. The rotational drag control assembly is fixedly connected to the structural support base, and the unwinding shaft abuts against the rotational drag control assembly.

[0008] By adopting the above technical solution, the structural support base is used to install the constant tension control yarn unwinding device on the frame, the unwinding shaft is used to connect the support fixture and the structural support base so that the support fixture can rotate relative to the structural support base, the support fixture is used to fix the yarn bobbin so that the yarn bobbin can rotate relative to the structural support base for yarn unwinding; the rotational drag-reducing support is used to support the unwinding shaft and reduce the rotational resistance of the unwinding shaft, reducing the influence of the weight change of the yarn bobbin installed at the support fixture on the rotational resistance of the unwinding shaft, thereby reducing the influence of the weight change of the yarn bobbin on the tension change during the yarn unwinding process; the unwinding shaft abuts against the rotational drag control component so that the rotational drag control component can adjust the rotational resistance of the unwinding shaft, thereby improving the stability of the tension during the yarn unwinding process.

[0009] In a preferred embodiment of this application: the structural support is provided with a friction control hole, the unwinding shaft is provided with a friction part at a position opposite to the friction control hole, the friction part and the friction control hole are clearance-fitted, and the rotation resistance control assembly includes a shaft end limiter rotatably connected to one end of the unwinding shaft away from the support fixture, and a pressure regulator with one end connected to the structural support and the other end connected to the shaft end limiter to adjust the contact pressure between the friction part and the friction control hole.

[0010] By adopting the above technical solution, the clearance fit between the friction part and the friction control hole improves the adjustment range of the contact pressure control; the shaft end limiter is used to control the position of the unwinding shaft away from the support fixture, so that the position of the shaft end limiter can be adjusted by the pressure regulator, thereby controlling the contact pressure between the friction part and the friction control hole, and thus adjusting the rotational resistance of the components on the unwinding shaft, so as to achieve the effect of controlling the yarn tension on the yarn bobbin installed on the support fixture.

[0011] In a preferred embodiment of this application: the inner wall of the friction control hole is provided with a first damping layer, and the surface of the friction part is provided with a second damping layer.

[0012] By adopting the above technical solution, a first damping layer and a second damping layer made of materials with clearly defined performance parameters are respectively provided on the contact surfaces of the friction control hole and the friction part, so as to clarify the friction coefficient of the contact surface, and thus facilitate the calculation and adjustment of the rotational resistance of the unwinding shaft by controlling the contact pressure between the friction part and the friction control hole.

[0013] In a preferred embodiment of this application: the pressure regulator includes an adjustment drive and an adjustment telescopic member, the adjustment drive is connected to the structural support base, the drive end of the adjustment drive is connected to the adjustment telescopic member to drive the adjustment telescopic member to extend or retract, and the telescopic end of the adjustment telescopic member is connected to the shaft end limiter.

[0014] By adopting the above technical solution, the adjusting drive is used to connect one end of the structural support base and the adjusting telescopic component, and the other end of the adjusting telescopic component is connected to the shaft end limiter, so that the adjusting drive can drive the telescopic component to adjust its extension state, and then adjust the position of the shaft end limiter or the force exerted by the telescopic component on the shaft end limiter. Since the shaft end limiter is connected to the unwinding shaft, the adjustment of the position or force of the shaft end limiter will act on the contact pressure of the friction control hole and the friction part, thereby realizing the adjustment of the yarn tension when the yarn bobbin is unwound.

[0015] In a preferred embodiment of this application: the shaft end limiter includes a limit shell and a limit bearing, the limit shell is connected to the telescopic end of the adjusting telescopic member, and the limit shell is rotatably connected to the unwinding shaft through the limit bearing.

[0016] By adopting the above technical solution, the shaft end limiter includes a limit bearing, and the shaft end limiter is rotatably connected to the unwinding shaft through the limit bearing, which can reduce the rotational resistance of the unwinding shaft; the limit shell is connected to the telescopic end of the adjusting telescopic component, so that the position of the shaft end limiter can be adjusted by adjusting the telescopic component, thereby adjusting the contact pressure between the friction control hole and the friction part.

[0017] In a preferred embodiment of this application: the rotational drag reduction support includes a support bearing, the outer ring of which is detachably and fixedly connected to the structural support base, and the inner ring of which is detachably and fixedly connected to the unwinding shaft. The installation position of the support bearing is axially adjustable relative to the unwinding shaft.

[0018] By adopting the above technical solution, the rotational drag-reducing support component, including the support bearing, achieves the functions of supporting the unwinding shaft and reducing rotational drag. Furthermore, the installation position of the support bearing relative to the unwinding shaft is axially adjustable, facilitating subsequent adjustment of the ratio between the force arm from the center of gravity of the friction part to the center of gravity of the support bearing and the force arm from the center of the friction part to the center of gravity of the limiting bearing. As the yarn on the bobbin is continuously consumed, its weight gradually decreases, thereby reducing the rotational resistance of the unwinding shaft. This, in turn, reduces the yarn tension due to the reduced rotational resistance of the unwinding shaft. On the other hand, the continuous consumption of yarn on the bobbin also causes the surface radius of the bobbin to gradually decrease. With the resistance torque on the bobbin remaining constant, this leads to an increase in yarn tension. The combined effect of these two factors—one increasing and one decreasing—results in a stable yarn tension.

[0019] In a preferred embodiment of this application, the adjusting drive element is a bolt, and the adjusting telescopic element is a spring.

[0020] By adopting the above technical solution, the adjustment drive component and the adjustment telescopic component are selected by a combination of bolts and springs, which has the advantages of simple structure and low cost. The rotation angle and number of turns of the bolt are directly proportional to the axial displacement of the bolt, and the extension and contraction of the spring are also directly proportional to the elastic force, which makes it easy to adjust the elastic force of the spring and calculate the rotation angle and number of turns of the bolt when it is necessary to adjust the yarn tension on the yarn bobbin.

[0021] In a preferred embodiment of this application: the structural support base is fixedly connected to an adjustable support plate, the end of the adjustable support plate away from the support fixture extending axially along the unwinding shaft to the shaft end limiter, for mounting a pressure regulator.

[0022] By adopting the above technical solution, the structural support base is fixedly connected with an adjustable support plate for installing the pressure regulator. The split design facilitates individual replacement and can adapt to different models of pressure regulators through different adjustable support plates, thereby reducing maintenance costs and improving adaptability.

[0023] In a preferred embodiment of this application: the support fixture includes a fixing part and a disassembly part. The fixing part is provided with a limiting step, and the disassembly part is provided with an annular positioning groove and a resistance-increasing ring disposed in the annular positioning groove. The side of the resistance-increasing ring that is used to contact the inner wall of the yarn bobbin is provided with several annular resistance-increasing ridges.

[0024] By adopting the above technical solution, the support fixture adopts a split design of fixed part and disassembly part, which helps to reduce the weight of the support fixture. The limiting step is used to limit the yarn bobbin in the fixed part. After the yarn bobbin is installed in the fixed part, the disassembly part is used to restrict the axial movement of the yarn bobbin. The annular positioning groove is used to install the resistance ring. The resistance ridge is used to increase the resistance of the support fixture to the yarn bobbin, so as to prevent the yarn bobbin from undergoing radial or circumferential relative displacement relative to the unwinding axis during the unwinding rotation.

[0025] In a preferred embodiment of this application: the support fixture includes a fixing part and a disassembly part. The fixing part is provided with a limiting step. The outer side wall of the disassembly part is provided with a plurality of positioning holes and a resistance-increasing post disposed in the positioning holes. The end of the resistance-increasing post used to contact the inner wall of the yarn tube is hemispherical.

[0026] By adopting the above technical solution, the support fixture adopts a split design of fixed part and disassembly part, which helps to reduce the self-weight of the support fixture. The limiting step is used to limit the yarn bobbin in the fixed part. After the yarn bobbin is installed in the fixed part, the disassembly part is used to restrict the axial movement of the yarn bobbin. The positioning hole is used to install the resistance pile. The resistance pile is used to increase the resistance of the support fixture to the yarn bobbin, so as to prevent the yarn bobbin from undergoing radial or circumferential relative displacement relative to the unwinding axis during the unwinding rotation.

[0027] The second objective of this invention is achieved by the following technical solution: A constant tension controlled yarn unwinding frame includes a frame and any of the aforementioned constant tension controlled yarn unwinding devices. Several constant tension controlled yarn unwinding devices are connected to both sides of the frame, and the constant tension controlled yarn unwinding devices are fixedly connected to the frame through the structural support base.

[0028] By adopting the above technical solution, the frame is used to install several constant tension control yarn unwinding devices on both sides, so as to improve the unit space density of yarn unwinding supply, improve production efficiency, and reduce the structural complexity when gathering yarns at different positions.

[0029] In summary, this application includes at least one of the following beneficial technical effects: 1. The structural support base is used to mount the constant tension controlled yarn unwinding device onto the frame. The unwinding shaft is used to connect the support fixture and the structural support base so that the support fixture can rotate relative to the structural support base. The support fixture is used to fix the yarn bobbin, allowing the yarn bobbin to rotate relative to the structural support base for yarn unwinding. The rotational drag-reducing support is used to support the unwinding shaft and reduce its rotational resistance, reducing the influence of the weight change of the yarn bobbin mounted at the support fixture on the rotational resistance of the unwinding shaft, thereby reducing the influence of the weight change of the yarn bobbin on the tension change during yarn unwinding. It abuts against the rotational resistance control component so that the rotational resistance of the unwinding shaft can be adjusted by the rotational resistance control component, thereby improving the stability of the tension during yarn unwinding; the clearance fit between the friction part and the friction control hole improves the adjustment range of the contact pressure control; the shaft end limiter is used to control the position of the unwinding shaft away from the support fixture so that the position of the shaft end limiter can be adjusted by the pressure regulator, thereby controlling the contact pressure between the friction part and the friction control hole, thereby adjusting the rotational resistance of the components on the unwinding shaft, so as to achieve the effect of controlling the yarn tension on the yarn bobbin installed on the support fixture.

[0030] 2. A first damping layer and a second damping layer, made of materials with clearly defined performance parameters, are respectively provided on the contact surfaces of the friction control hole and the friction part, so as to determine the friction coefficient of the contact surface, and thus facilitate the calculation and adjustment of the rotational resistance of the unwinding shaft by controlling the contact pressure between the friction part and the friction control hole.

[0031] 3. The adjusting drive is used to connect one end of the structural support base and the adjusting telescopic component. The other end of the adjusting telescopic component is connected to the shaft end limiter, so that the adjusting drive can drive the telescopic component to extend or retract, thereby adjusting the position of the shaft end limiter or the force exerted by the telescopic component on the shaft end limiter. Since the shaft end limiter is connected to the unwinding shaft, the adjustment of the position or force of the shaft end limiter will affect the contact pressure between the friction control hole and the friction part, thereby realizing the adjustment of the yarn tension during unwinding of the yarn package. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the constant tension control yarn unwinding device in Embodiment 1 of this application.

[0033] Figure 2 This is a schematic diagram of the disassembly and assembly part in Scheme 1 of Embodiment 1 of this application.

[0034] Figure 3 This is a schematic diagram of the disassembly and assembly part in Scheme 2 of Embodiment 1 of this application.

[0035] Figure 4 This is a top view schematic diagram of the constant tension control wire feeding frame in Embodiment 2 of this application.

[0036] Figure 5 This is a side view of the constant tension control wire feeding frame in Embodiment 2 of this application.

[0037] Explanation of reference numerals in the attached figures: 1. Structural support base; 11. Friction control hole; 12. First damping layer; 2. Support fixture; 21. Fixing part; 211. Limiting step; 22. Disassembly part; 221. Annular positioning groove; 222. Resistance ring; 2221. Resistance ridge; 223. Positioning hole; 224. Resistance pile; 3. Unwinding shaft; 31. Friction part; 32. Second damping layer; 4. Rotational resistance reduction support; 5. Rotational resistance control assembly; 51. Shaft end limiter; 511. Limiting shell; 512. Limiting bearing; 52. Pressure regulator; 521. Adjustment drive; 522. Adjustment telescopic component; 6. Adjustment support plate; 7. Frame. Detailed Implementation

[0038] The following is in conjunction with the appendix Figures 1 to 5 This application will be described in further detail. Example

[0039] In this embodiment, the fixedly connected components do not move relative to each other during device operation. Specifically, the connection can be detachable or non-detachable. The connection in this embodiment can be direct or indirect.

[0040] Reference Figure 1This application discloses a constant tension controlled yarn unwinding device, including a structural support base 1, a support fixture 2, an unwinding shaft 3, a rotational drag-reducing support 4, and a rotational drag control component 5. The unwinding shaft 3 can be made of high-hardness aluminum alloy, carbon steel, or preferably carbon steel, with the following material selection criteria: hardness range of 18 to 60 HRC, and straightness range of 0.05 to 0.2 mm. The unwinding shaft 3 is rotatably connected to the structural support base 1 via the rotational drag-reducing support 4. The support fixture 2 is sleeved and fixedly connected to the unwinding shaft 3. The rotational drag control component 5 is fixedly connected to the structural support base 1, and the unwinding shaft 3 abuts against the rotational drag control component 5. The structural support base 1 is used to install the constant tension controlled yarn unwinding device on the machine frame. 7. The unwinding shaft 3 is used to connect the support fixture 2 and the structural support base 1 so that the support fixture 2 can rotate relative to the structural support base 1. The support fixture 2 is used to fix the yarn bobbin so that the yarn bobbin can rotate relative to the structural support base 1 for yarn unwinding. The rotational resistance reducing support 4 is used to support the unwinding shaft 3 and reduce the rotational resistance of the unwinding shaft 3, thereby reducing the influence of the weight change of the yarn bobbin installed at the support fixture 2 on the rotational resistance of the unwinding shaft 3, and thus reducing the influence of the weight change of the yarn bobbin on the tension change during the yarn unwinding process. The unwinding shaft 3 abuts against the rotational resistance control component 5 so that the rotational resistance of the unwinding shaft 3 can be adjusted by the rotational resistance control component 5, thereby improving the stability of the tension during the yarn unwinding process.

[0041] The structural support 1 is provided with a friction control hole 11. When the unwinding shaft 3 is installed on the structural support 1, a friction part 31 is provided at the position opposite to the friction control hole 11 on the unwinding shaft 3. The friction part 31 and the unwinding shaft 3 can be integrally formed, or they can be detachably separated according to actual needs. The friction part 31 and the friction control hole 11 are clearance-fitted, and the surfaces of the friction part 31 and the friction control hole 11 that contact each other are located on a uniform cylindrical surface. The inner wall of the friction control hole 11 is provided with a first damping layer 12, and the surface of the friction part 31 is provided with a second damping layer 32. Preferably, the first damping layer 12 is provided with a second damping layer 32. The first damping layer 12 and the second damping layer 32 are surface treatment layers respectively disposed on the surfaces of the friction control hole 11 and the friction part 31. The first damping layer 12 needs to enhance wear resistance. The material of the part where the friction control hole 11 is disposed can be a high-hardness material such as aluminum alloy, carbon steel, titanium alloy, or stainless steel. The surface treatment method of the first damping layer 12 can be anodizing, electroplating, etc. The hardness range of the first damping layer 12 should be controlled between 20 and 60 HRC. The second damping layer 32 needs to enhance low friction coefficient performance. The material of the friction part 31 can be ceramic, engineering plastic, tungsten carbide, etc. Additive materials such as molybdenum disulfide and graphite are added according to actual needs. The coefficient of friction between the first damping layer 12 and the second damping layer 32 should be controlled between 0.03 and 0.5, preferably between 0.03 and 0.3. In other embodiments of this application, one or both of the first damping layer 12 and the second damping layer 32 can be set as a coating, a surface treatment layer, or an independent part according to actual needs. When the first damping layer 12 or the second damping layer 32 is an independent part, the selection of materials and surface treatment processes should refer to the above-mentioned friction control hole 11 or friction part 31. Both the contact surfaces of the hole 11 and the friction part 31 are provided with a first damping layer 12 and a second damping layer 32 made of materials with clearly defined performance parameters, so as to determine the friction coefficient of the contact surface, and thus facilitate the calculation and adjustment of the rotational resistance of the unwinding shaft 3 by controlling the contact pressure between the friction part 31 and the friction control hole 11. In other embodiments of this application, one or more grooves may be provided on the surface of the friction part 31, so as to facilitate the adjustment of the friction coefficient by controlling the contact area, and to facilitate the increase of the air contact area on its surface, thereby improving heat dissipation efficiency and reducing the change of friction coefficient caused by temperature changes.

[0042] The resistance control assembly 5 includes a shaft end limiter 51 and a pressure regulator 52. An adjusting support plate 6 is fixedly connected to the structural support base 1. The shaft end limiter 51 is rotatably connected to the end of the unwinding shaft 3 away from the support fixture 2. The connection method can be direct connection or indirect connection via couplings or other components, depending on actual needs. The shaft end limiter 51 restricts the radial movement of the end of the unwinding shaft 3 away from the support fixture 2. The length of the adjusting support plate 6 at the end away from the support fixture 2 extends axially along the unwinding shaft 3 to at least exceed the length of the shaft end limiter 51, for mounting the pressure regulator 52. One end of the pressure regulator 52 is fixedly connected to the adjusting support plate 6, and thus indirectly connected to the structural support base 1. The other end of the pressure regulator 52 is connected to... The shaft end limiter 51 is used to adjust the contact pressure between the friction part 31 and the friction control hole 11. The clearance fit between the friction part 31 and the friction control hole 11 improves the adjustment range of the contact pressure control. The shaft end limiter 51 is used to control the position of the unwinding shaft 3 away from the support fixture 2, so that the position of the shaft end limiter 51 can be adjusted by the pressure regulator 52, thereby controlling the contact pressure between the friction part 31 and the friction control hole 11, and thus adjusting the rotational resistance of the components on the unwinding shaft 3, so as to achieve the effect of controlling the yarn tension on the yarn bobbin installed on the support fixture 2. The structural support base 1 is provided with an adjustment support plate 6. The split design makes it easy to replace individually, and different models of pressure regulators 52 can be adapted by different adjustment support plates 6, reducing maintenance costs and improving adaptability.

[0043] The pressure regulator 52 includes an adjustment drive 521 and an adjustment telescopic member 522. The adjustment drive 521 is connected to the adjustment support plate 6. The drive end of the adjustment drive 521 is connected to the adjustment telescopic member 522 to drive the adjustment telescopic member 522 to extend or retract. One end of the adjustment telescopic member 522 is connected to the adjustment drive 521, and the other telescopic end is connected to the shaft end limiter 51. Preferably, the adjustment drive 521 is a bolt, and the adjustment telescopic member 522 is a spring. The bolt-type adjustment drive 521 is threadedly connected to the adjustment support plate 6, and its bottom is fixedly connected to one end of the spring-type adjustment telescopic member 522. The other end of the spring-type adjustment telescopic member 522 is fixedly connected to the shaft end limiter 51. Preferably, the normal working state of the spring-type adjustment telescopic member 522 is when it is stretched. In other embodiments of this application, the spring-type adjustment telescopic member 522 when it is compressed in its normal working state can also be used according to actual needs. The adjustment drive 521 is used for connecting structures. One end of the support base 1 and the adjusting telescopic component 522 are connected to the shaft end limiter 51, and the other end of the adjusting telescopic component 522 is connected to the shaft end limiter 51. This allows the adjusting drive component 521 to drive the telescopic component 522 to extend or retract, thereby adjusting the position of the shaft end limiter 51 or the force exerted by the telescopic component 522 on the shaft end limiter 51. The adjusting drive component 521 and the adjusting telescopic component 522 are a combination of bolts and springs, which has the advantages of simple structure and low cost. The rotation angle and number of turns of the bolt are proportional to the axial displacement of the bolt, and the extension and retraction of the spring are also proportional to the elastic force, making it easy to adjust the elastic force of the spring and calculate the rotation angle and number of turns of the bolt when it is necessary to adjust the yarn tension on the yarn bobbin. Since the shaft end limiter 51 is connected to the unwinding shaft 3, the adjustment of the position or force of the shaft end limiter 51 will act on the contact pressure between the friction control hole 11 and the friction part 31, thereby realizing the adjustment of the yarn tension when the yarn bobbin is unwound.

[0044] In other embodiments of this application, the combination of the adjusting telescopic member 522 can also be a pneumatic rod, a hydraulic rod, a linear motor, etc. As those skilled in the art know, when using a pneumatic rod, a hydraulic rod, a linear motor, etc. as the adjusting telescopic member 522, the corresponding device should be selected as the adjusting drive member 521 according to actual needs.

[0045] The shaft end limiter 51 includes a limit housing 511 and a limit bearing 512. The limit housing 511 is connected to the telescopic end of the adjusting telescopic member 522, and the limit housing 511 is rotatably connected to the unwinding shaft 3 via the limit bearing 512. Preferably, the inner ring of the limit bearing 512 is fixedly connected to the unwinding shaft 3, and the outer ring of the limit bearing 512 is fixedly connected to the limit housing 511. The limit bearing 512 should be a high-precision bearing, preferably a ball bearing, with a radial runout range of 2.5 to 10 μm for the inner ring, a radial runout range of 2.5 to 15 μm for the outer ring, and an axial runout range of 3 μm to 15 μm for the inner ring. The shaft end limiter 51 is rotatably connected to the unwinding shaft 3 via the limit bearing 512, which can reduce the rotational resistance of the unwinding shaft 3. The limit housing 511 is connected to the telescopic end of the adjusting telescopic member 522 so that the position of the shaft end limiter 51 can be adjusted by adjusting the telescopic member 522, thereby adjusting the contact pressure between the friction control hole 11 and the friction part 31.

[0046] The distance from the center of gravity of the friction part 31 to the center of gravity of the support bearing is defined as the first lever arm A, and the distance from the center of the friction part 31 to the center of gravity of the limiting bearing 512 is defined as the second lever arm B. Preferably, the ratio A / B of the first lever arm to the second lever arm is in the range of [1, 4] to accommodate yarn bobbin weights from 200g to 10kg. The yarn bobbin weight refers to the total weight of the yarn and the paper tube. The rotational drag reduction support 4 is mounted on the structural support base 1. The rotational drag reduction support 4 includes a support bearing and other necessary connecting parts. The outer ring of the support bearing is detachably fixed to the structural support base 1, and the inner ring is detachably fixed to the unwinding shaft 3, thereby realizing the support and rotational drag reduction functions for the unwinding shaft 3. Moreover, the installation position of the support bearing is axially adjustable relative to the unwinding shaft 3, which facilitates the subsequent adjustment of the ratio of the first lever arm A to the second lever arm B by adjusting the installation position of the support bearing. The tension on the yarn on the yarn bobbin is defined as F, the resistance torque on the yarn bobbin is defined as T, and the radius of the yarn bobbin is defined as... R, F=T / R. As the yarn on the bobbin is continuously consumed, the weight of the bobbin gradually decreases, thereby reducing the rotational resistance of the unwinding shaft 3. This leads to a decrease in yarn tension due to the reduced rotational resistance of the unwinding shaft 3. On the other hand, the continuous consumption of yarn on the bobbin causes the surface radius R of the bobbin to gradually decrease. With the resistance torque T on the bobbin remaining constant, this results in an increase in yarn tension F. The effects of the decrease in the rotational resistance of the unwinding shaft 3 and the decrease in the bobbin radius on yarn tension are one increase and one decrease, thus achieving the effect of stabilizing yarn tension. However, different bobbins have different rates of influence on the bobbin radius R as yarn is consumed. To balance the effects of the decrease in the rotational resistance of the unwinding shaft 3 and the decrease in the bobbin radius on yarn tension, the ratio A / B of the first lever arm and the second lever arm, as well as the friction coefficient between the first damping layer and the second damping layer, can be adjusted to achieve a match between the three, thereby improving the stability of yarn tension during the unwinding process.

[0047] The support fixture 2 includes a fixing part 21 and a disassembly part 22. The support fixture 2 adopts a split design of the fixing part 21 and the disassembly part 22, which helps to reduce the weight of the support fixture 2. The fixing part 21 is provided with a limiting step 211, which is used to limit the yarn bobbin at the fixing part 21. Preferably, the disassembly part 22 adopts the following two preferred solutions, but is not limited to the following two preferred solutions: Option 1: Refer to Figure 2 The disassembly and assembly part 22 is provided with an annular positioning groove 221 and a resistance ring 222 disposed in the annular positioning groove 221. The side of the resistance ring 222 that is used to contact the inner wall of the yarn bobbin is provided with several annular resistance ridges 2221. The resistance ring 222 can be made of elastic material. When the yarn bobbin is installed in the fixing part 21, the disassembly and assembly part 22 is used to restrict the axial movement of the yarn bobbin. The annular positioning groove 221 is used to install the resistance ring 222. The resistance ridges 2221 are used to increase the resistance of the support fixture 2 to the yarn bobbin, so as to prevent the yarn bobbin from undergoing radial or circumferential relative displacement relative to the unwinding shaft 3 during the unwinding rotation.

[0048] Option 2: Refer to Figure 3 The outer wall of the disassembly and assembly part 22 is provided with a number of positioning holes 223 and resistance-increasing posts 224 disposed in the positioning holes 223. The end of the resistance-increasing post 224 that is used to contact the inner wall of the yarn bobbin is hemispherical. The resistance-increasing post 224 can be made of elastic material. After the yarn bobbin is installed in the fixing part 21, the disassembly and assembly part 22 is used to restrict the axial movement of the yarn bobbin. The positioning holes 223 are used to install the resistance-increasing posts 224. The resistance-increasing posts 224 are used to increase the resistance of the support fixture 2 to the yarn bobbin, so as to prevent the yarn bobbin from undergoing radial or circumferential relative displacement relative to the unwinding shaft 3 during the unwinding rotation.

[0049] Tests showed that the best results were achieved when the basic yarn tension was between 1 and 5 N·m. The tension fluctuation was within ±15% when the yarn bobbin weight was less than 10 kg, within ±10% when the yarn bobbin weight was less than 8 kg, within ±8% when the yarn bobbin weight was less than 5 kg, and within ±5% when the yarn bobbin weight was less than 2 kg.

[0050] Implementation principle of the example: When in use, several constant tension controlled yarn unwinding devices are mounted on a frame 7 via a structural support base 1, so that multiple yarns can be drawn from the frame 7 for subsequent processing. Several yarn bobbins are mounted on a support fixture 2 in the same unwinding direction. Resistance is applied to the inner wall of the yarn bobbin by the resistance ring 222 and resistance ridge 2221 of scheme one or the resistance pile 224 of scheme two on the support fixture 2, so as to effectively prevent the yarn bobbin from undergoing radial or circumferential relative displacement relative to the unwinding shaft 3 during high-speed rotation.

[0051] When the yarn is unwound, the traction force acts directly on the yarn. The elasticity of the spring-type adjusting telescopic component 522 is controlled by the rotating bolt-type adjusting drive component 521. The other end of the spring-type adjusting telescopic component 522 acts on the shaft end limiter 51, thereby achieving the effect of adjusting the tension on the shaft end limiter 51. This causes the contact pressure between the friction part 31 and the friction control hole 11 to change. Since the coefficient of friction between the first damping layer 12 on the surface of the friction control hole 11 and the second damping layer 32 on the surface of the friction part 31 is known, the friction force between the first damping layer 12 and the second damping layer 32 is proportional to the contact pressure, thereby achieving precise control of the rotational resistance of the yarn unwinding shaft 3.

[0052] The constant tension control yarn unwinding device controls the ratio A / B of the first and second lever arms by adjusting the axial installation position of the support bearing to accommodate yarn bobbins of different sizes. As the yarn on the bobbin is continuously consumed, the bobbin's weight gradually decreases, thereby reducing the rotational resistance of the unwinding shaft 3. Consequently, the yarn tension decreases due to the reduced rotational resistance of the unwinding shaft 3. On the other hand, the continuous consumption of yarn on the bobbin causes the surface radius R of the bobbin to gradually decrease. With the resistance torque T on the bobbin remaining constant, this leads to an increase in yarn tension F. The decrease in the rotational resistance of the unwinding shaft 3 and the decrease in the bobbin radius have opposite effects on the yarn tension, thus reducing the influence of the bobbin's own weight on the rotational resistance of the unwinding shaft 3. This ensures that the yarn tension during unwinding does not change with the change in the bobbin's own weight, further improving the yarn tension stability during the unwinding process. Example

[0053] This application discloses a constant tension controlled yarn feeding frame, such as... Figure 4 , Figure 5 As shown, the constant tension control unwinding frame includes a frame 7 and any of the constant tension control yarn unwinding devices in the above embodiments. Several constant tension control yarn unwinding devices are detachably connected to both sides of the frame 7. Several structural support seats 1 located on the same side of the frame 7 are distributed in a rectangular dot matrix. Preferably, the constant tension control yarn unwinding devices can be arranged in seven layers on one side of the frame 7, and each layer can install 2 to 20 constant tension control yarn unwinding devices. Each constant tension control yarn unwinding device is fixedly connected to the frame 7 through the structural support seat 1. The frame 7 is used to install several constant tension control yarn unwinding devices on both sides in order to improve the unit space density of yarn unwinding supply, improve production efficiency, and reduce the structural complexity when gathering yarns at different positions.

[0054] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A constant tension control yarn unwinding device, characterized in that, The assembly includes a structural support base (1), a support fixture (2), a dewinding shaft (3), a rotational drag-reducing support (4), and a rotational drag control assembly (5). The dewinding shaft (3) is rotatably connected to the structural support base (1) via the rotational drag-reducing support (4). The support fixture (2) is sleeved and fixedly connected to the dewinding shaft (3). The rotational drag control assembly (5) is fixedly connected to the structural support base (1), and the dewinding shaft (3) abuts against the rotational drag control assembly (5). The structural support base (1) is provided with a friction control hole (11). A friction part (31) is provided at a position opposite to the friction control hole (11) on the unwinding shaft (3). The friction part (31) and the friction control hole (11) are in clearance fit. The rotation resistance control assembly (5) includes a shaft end limiter (51) rotatably connected to one end of the unwinding shaft (3) away from the support fixture (2), and a pressure regulator (52) with one end connected to the structural support base (1) and the other end connected to the shaft end limiter (51) to adjust the contact pressure between the friction part (31) and the friction control hole (11).

2. The constant tension controlled yarn unwinding device according to claim 1, characterized in that: The inner wall of the friction control hole (11) is provided with a first damping layer (12), and the surface of the friction part (31) is provided with a second damping layer (32).

3. The constant tension controlled yarn unwinding device according to claim 1, characterized in that: The pressure regulator (52) includes an adjustment drive (521) and an adjustment telescopic member (522). The adjustment drive (521) is connected to the structural support base (1). The drive end of the adjustment drive (521) is connected to the adjustment telescopic member (522) to drive the adjustment telescopic member (522) to extend or retract. The telescopic end of the adjustment telescopic member (522) is connected to the shaft end limiter (51).

4. The constant tension controlled yarn unwinding device according to claim 1, characterized in that: The shaft end limiter (51) includes a limit shell (511) and a limit bearing (512). The limit shell (511) is connected to the telescopic end of the adjusting telescopic member (522). The limit shell (511) is rotatably connected to the unwinding shaft (3) through the limit bearing (512).

5. The constant tension controlled yarn unwinding device according to claim 4, characterized in that: The rotational drag reduction support (4) includes a support bearing, the outer ring of which is detachably and fixedly connected to the structural support base (1), and the inner ring of which is detachably and fixedly connected to the unwinding shaft (3). The installation position of the support bearing is axially adjustable relative to the unwinding shaft (3).

6. The constant tension controlled yarn unwinding device according to claim 3, characterized in that: The adjusting drive component (521) is a bolt, and the adjusting telescopic component (522) is a spring.

7. The constant tension controlled yarn unwinding device according to claim 1, characterized in that: The structural support base (1) is fixedly connected to an adjusting support plate (6). The end of the adjusting support plate (6) away from the support fixture (2) extends along the axial direction of the unwinding shaft (3) to the shaft end limiter (51) for installing a pressure regulator (52).

8. The constant tension controlled yarn unwinding device according to claim 1, characterized in that: The support fixture (2) includes a fixing part (21) and a disassembly part (22). The fixing part (21) is provided with a limiting step (211). The disassembly part (22) is provided with an annular positioning groove (221) and a resistance ring (222) provided in the annular positioning groove (221). The side of the resistance ring (222) that is used to contact the inner wall of the yarn tube is provided with several annular resistance ridges (2221).

9. The constant tension controlled yarn unwinding device according to claim 1, characterized in that: The support fixture (2) includes a fixing part (21) and a disassembly part (22). The fixing part (21) is provided with a limiting step (211). The outer side wall of the disassembly part (22) is provided with a plurality of positioning holes (223) and a resistance booster (224) disposed in the positioning holes (223). The end of the resistance booster (224) used to contact the inner wall of the yarn tube is hemispherical.

10. A constant tension control wire feeding frame, characterized in that: Includes a frame (7) and the constant tension control yarn unwinding device according to any one of claims 1-9. Both sides of the frame (7) are connected to a plurality of the constant tension control yarn unwinding devices. The constant tension control yarn unwinding devices are fixedly connected to the frame (7) through the structural support base (1).

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