RIGID-FLEXIBLE COUPLING MECHANISM WITH VARIABLE ROD LENGTH FOR FIBRE BUNDLE TENSION CONTROL

The invention discloses a rigid-flexible coupling mechanism with variable rod length for fibre bundle tension control. In the transmitting process, the fibre bundle passes through the front guide roller, the tension regulating roller and the back guide roller sequentially. The front and back guide rollers have fixed positions, while the tension regulating roller has an adjustable position to regulate the fibre bundle tension. The invention uses the variable rod length rigid-flexible coupling mechanism with a combination of a servo motor and an electric actuator in a dual drive control mode, which can choose to use either a four-rod fixed length mechanism or a five-rod variable length mechanism to regulate the tension under different working conditions. This provides a more flexible control method, increases the regulating range of fibre bundle tension, improves the system response speed and regulation accuracy, and effectively avoids the wear of fibre bundle caused by tension fluctuations.

FIELD OF THE INVENTION

The invention relates to a tension control mechanism for fibre bundle transmission processes. In specific, it is a rigid-flexible coupling mechanism with variable rod length for fibre bundle tension control.

BACKGROUND OF THE INVENTION

During the transmitting process of fibre bundles, tension fluctuation is one of the most important influences that can cause wear, pilling, breakage and even reduce the quality of the structured product. Since the fibre bundles usually undergo a complex transfer process with long path and multiple rollers from feeding to shaping which causes apparent tension fluctuations, how to achieve precise control of fibre bundle tension and improve product quality has become one of the important research directions.

At present, most common structure of fibre bundle tension control mechanism uses dance roller or swing rod. The tension regulating roller of these structures can only do linear movement or circular oscillation in a certain direction, and the driving mode generally adopts a single drive of motor or cylinder to adjust the position of the roller to achieve the tension control.

The existing single degree of freedom or fixed rod length structure of the fibre bundle tension control mechanism is limited by its space position and structure. The movement trajectory of the regulating roller is restricted, the tension control range is small, and the single rod structure is unstable, which cause the hardness of precise tension control. Meanwhile, pure rigid structure has higher stiffness, the accuracy of tension control may be affected by the inertia effect of structure movement and insufficient. Moreover, the fibre bundles constant tension and low wear transmission are limited, which has a lower reliability.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned problem of tension control mechanism for fibre bundle transmission, the invention proposes a rigid-flexible coupling mechanism with variable rod length for fibre bundle tension control, which uses a combination of a servo motor and an electric actuator in a dual drive control mode. By changing the length and angle of the tension regulating rod, a four-rod fixed length mechanism or a five-rod variable length mechanism can be selected according to the size of tension fluctuations and the control range. The position of the tension regulating roller is adjusted to further regulate the fibre bundle tension which realizes a constant tension transmission.

The invention for fibre bundle tension control of rigid-flexible coupling mechanism with variable rod length, comprising a front guide roller, a back guide roller and a tension regulating roller provided between them.

The tension regulating roller is mounted on an up-and-down movable bracket on the swing frame, the swinging of the swing frame and the sliding of the tension regulating roller are controlled by a servo motor and an electric actuator in a dual drive mode, where an end of a main body of the electric actuator is connected to the servo motor, and the rod of the electric actuator is connected to one side of the bracket by a rotating shaft.

The invention for fibre bundle tension control of rigid-flexible coupling mechanism with variable rod length, which can achieve fast response to tension regulation or arbitrary trajectory adjustment of the tension regulating rollers by choosing either a four-rod fixed length or a five-rod variable length mechanism based on different working conditions.

When a tension control range is small and the fast response to the tension regulation is required, the four-rod fixed length mechanism is used for tension control. When the tension increases, an output shaft of the servo motor rotates clockwise to drive the electric actuator to rotate clockwise around a motor axis of the servo motor, and an angle of the rod of the electric actuator changes to drive the swing frame to rotate clockwise around a spindle. Meanwhile, the bracket drives the tension regulating roller to move downwards, such that distances between the tension regulating roller and the front guide roller and between the tension regulating roller and the back guide roller are reduced to achieve tension reduction. Conversely, when the tension decreases during a transmission process of the fibre bundle, the servo motor reverses to drive the swing frame to rotate counterclockwise, the tension regulating roller moves upwards, and the distances between the tension regulating roller and the front guide roller and between the tension regulating roller and the back guide roller are increased to increase the tension of the fibre bundle.

When the tension control range is large and a change in a position of the tension regulating roller is required to be along any trajectory, the five-rod variable length mechanism is used for the tension control. When the tension increases, the output shaft of the servo motor rotates clockwise to drive the electric actuator to rotate clockwise around the motor axis, and the electric actuator drives the rod thereof to contract, and the angle and a length of the rod change to drive the swing frame to rotate counterclockwise around the spindle. Meanwhile, the bracket drives the tension regulating roller to move downwards, such that the distances between the tension regulating roller and the front guide roller and between the tension regulating roller and the back guide roller are reduced to achieve tension reduction. Conversely, when the tension decreases during the transmission process of the fibre bundle, the servo motor reverses and the rod is extended to drive the swing frame to rotate clockwise, the tension regulating roller moves upwards, and the distances between the tension regulating roller and the front guide roller and between the tension regulating roller and the back guide roller are increased to increase the tension of the fibre bundle

The Advantages of the Invention

1. The invention for fibre bundle tension control of rigid-flexible coupling mechanism with variable rod length, can choose to use either a four-rod fixed length or five-rod variable length tension control mechanism according to different working conditions (tension fluctuation size, control range, etc.), which is a more flexible control method.

2. The invention for fibre bundle tension control of rigid-flexible coupling mechanism with variable rod length, is RRPR mechanism when using the servo motor to single drive four-rod fixed length tension control mechanism. It has simple control mode and fast response time, also the control mechanism can achieve a rapid tension regulation.

3. The invention for fibre bundle tension control of rigid-flexible coupling mechanism with variable rod length, is RPRPR mechanism when using the servo motor and electric actuator to dual drive five-rod variable length tension control mechanism. The tension regulating roller has wider movement trajectory range which avoid a large structure size of traditional dance roller or swing rod to achieve a wide range of tension control. Moreover, the space structure is more compact, the control mechanism can realize an accurate tension regulation.

4. The invention for fibre bundle tension control of rigid-flexible coupling mechanism with variable rod length, has a stable triangular structure formed by the tension regulating rod, pendulum, and the base during tension control process. Which improves the instability of the traditional single rod structure and the tension control accuracy.

5. The invention for fibre bundle tension control of rigid-flexible coupling mechanism with variable rod length, combines flexible springs and rigid rod control mechanism. The springs are compressed or extended during tension regulation, plays a roll as a buffer, reduces the mechanism movement inertia effect on the position of tension regulating roller, and increases the stability of regulating system.

DETAILED DESCRIPTION OF EMBODIMENTS

The following detailed description describes in detail the characteristics and advantages of the instant disclosure, whose content is sufficient to enable any person skilled in the relevant art to understand the technical content of the instant disclosure and implement accordingly, and according to the content, the claims and figures disclosed by the present specification, any person skilled in the relevant art can easily understand the purpose and advantages of the instant disclosure. The following embodiments further illustrate the aspects of the instant disclosure, but do not limit the scope of the instant disclosure with any aspects.

The invention for fibre bundle tension control of rigid-flexible coupling mechanism with variable rod length, comprising base1, front guide roller2, back guide roller3, servo motor4, swing frame5, bracket6, electric actuator7, spring substrate8, springs9and tension regulating roller10, as shown inFIGS.1and2.

The base1is designed as a rectangular cross-sectional platform, the front guide roller2and the back guide roller3are equipped at the front and back of the base1middle respectively through the front guide roller substrate11and the rear guide roller substrate12. The bottom of the front guide roller substrate11is bolted to the left and right sides of the base1, and the top is fixed with both ends of the front guide shaft, on which the front guide roller2is coaxially mounted by bearings. Similarly, the bottom of the back guide roller substrate12is bolted to the left and right sides of the base1, and the top is fixed with both ends of the back guide shaft, on which the back guide roller3is coaxially mounted by bearings.

The servo motor4is mounted in front of the front guide roller2through a motor mounting substrate13, the bottom of the motor mounting substrate13is bolted to one side of the base1and the top is fixed with the servo motor4. Moreover, the output shaft of the servo motor4is set axially along the left and right direction.

The swing frame5has a left pendulum, a right pendulum and a top beam, and the top of the left and right pendulums are connected to both ends of the top beam, which forms an integrated U-shaped frame. The bottoms of the left and right pendulums are mounted on the base1through swing frame spindle14, positioned between the front2and back guide rollers3, so that the swing frame5can swing around the swing frame spindle14in a fixed position with variable angles. The above-mentioned left and right pendulums are fitted with guide rails15along their respective axes on opposite sides for mounting the bracket6.

The bracket6is a U-shaped frame with recesses16on the left and right outside walls, which are slidingly connected with the guide rails15on the left and right pendulums respectively, so that the bracket6can slide along the guide rails15. Moreover, there is a distance between the ground of the recesses16and the guide rails15for setting the tension regulating roller10, as shown inFIG.3. The tension regulating roller10is mounted on the regulating roller shaft through bearings. Both ends of the regulating roller shaft are fixed to both sides of the bracket6through bolts and positioned at the bottom of the recesses16on both sides of the bracket6, so that the tension regulating roller10can move up and down with the bracket6together along the guide rail15.

Both sides of the spring substrate8is bolted to the left and right pendulums on the swing frame5and positioned below the guide rail15. The upper surface of the spring substrate8is bolted to the bottom of two springs9, which are set along the left and right pendulums respectively, and the top is bolted to the bracket. When the tension regulating roller10and the bracket6reciprocally moving along the guide rail15on the swing frame5, the usage of the springs9can eliminate the effect of inertia which cannot be solved by purely rigid structures and provide a cushioning effect on the up and down movement of the tension regulating roller10. By using a double spring9connection in the invention, it is possible to avoid the unbalanced forces and torque of the bracket6caused by a single spring9extending or compressing, which further affects the accuracy of tension regulation.

The axis of electric actuator7is set perpendicular to the output shaft of the servo motor4. The end of the electric actuator7main body is connected to the output shaft of the servo motor4via a coupling. The rod part of the electric actuator7acts as the tension regulating rod17, and the output end of that is connected to the bottom side of the bracket6via a rotating shaft to achieve that the regulating rod can rotate around the rotating shaft on one side of the bracket6in a fixed position with variable angles. Therefore, the angle of the tension regulating rod17can be adjusted by the rotation of the electric actuator7along the servo motor4axis, which is driven by the rotation of the servo motor4. The length of the tension regulating rod17can be adjusted by telescoping along the direction of electric actuator7axis, which is controlled by the electric actuator7.

With the aforementioned design of a rigid-flexible coupling mechanism with variable rod length for fibre bundle tension control, the fibre bundle18is transmitted from the bottom of the front guide roller2to the top of the tension regulating roller10and then to the next mechanism via the bottom of the back guide roller3, which shows that the position of the tension regulating roller10determines the tension during the transmission of the fibre bundle18. Therefore, during the fibre transmitting process, the up, down, back, and forth position of tension regulating rollers10can be adjusted respectively through the motor and the electric actuator7, and the fibre tension control can be achieved by adjusting the relative positions between the three rollers (front guide roller2, tension regulating roller10and back guide roller3). Moreover, the stability of the tension regulating mechanism during the fibre bundles18transmission is ensured because of a triangular structure formed by the swing frame5, the tension regulating rod17and the base1. Which can also avoid the tension fluctuations caused by the structure instability and improve the tension regulation accuracy. The surface of the front guide roller2, the tension regulating roller10and the back guide roller3can also be designed with a concave structure to act as an axial limit for fibre bundles18, which can avoid tension fluctuations caused by fibre swinging during the transmitting process.

The invention for fibre bundle tension control of rigid-flexible coupling mechanism with variable rod length, when regulating the tension can choose four-rod fixed length or five-rod variable length mechanism according to different working conditions. Also, it can achieve a fast tension regulating response or arbitrary adjust the tension regulating roller10trajectory and increase the tension regulation range to meet different tension regulation requirements, with flexible and reliable methods.

When the tension control range is small and a fast response to tension control is required, a four-rod fixed length tension control mechanism is used to regulate the tension, as shown inFIG.4. The fibre bundles18is transmitted to the tension regulating roller10via the front guide roller2and then to the next mechanism through the back guide roller3. The fibre bundle18is wound counterclockwise, clockwise and counterclockwise at the front guide roller2, the tension regulating roller10and the back guide roller3respectively, and the position of the front2and back guide rollers3is fixed, the tension of the fibre bundle18is regulated by controlling the position of the tension regulating roller10. The initial positions and states of the swing frame5, the tension regulating roller10, the tension regulating rod17and the electric actuator7during the transmission of the fibre bundle18are shown in the dashed part ofFIG.4. When tension becomes large, the controller outputs a control signal, and the mechanism completes the following active actions. The output shaft of servo motor4rotates clockwise, driving electric actuator7to rotate clockwise around the axis of servo motor4. Due to the angle change of tension regulating rod17, swing frame5is driven to rotate counterclockwise around the spindle. Meanwhile, bracket6drives tension regulating roller10moves along guide rail15in the direction close to swing frame spindle14, the spring9is compressed which makes the distance between the tension regulating roller10and the front guide roller2and the back guide roller3decreasing, as shown in the solid part inFIG.4. Thus, reducing the tension and achieving the tension regulation of the fibre bundle18. Conversely, when the tension of the fibre bundle18decreases during transmission, the servo motor4reverses and drives the swing frame5to rotate clockwise, the tension regulating roller10moves away from the swing frame spindle14, the spring9is stretched and the distance between the front guide roller2and the back guide roller3increases to achieve an increase in the tension of the fibre bundle18. As the four-rod tension control mechanism is only driven by a single motor at this point, the tension control response is fast and can achieve rapid tension regulation.

When the tension control range is large and the position change of the tension regulating roller10is required along an arbitrary trajectory, a five-rod variable length tension control mechanism is used to regulate the tension, as shown inFIG.5. The initial position and state of the front guide roller2, tension regulating roller10, tension regulating rod17and electric actuator7during the transmission of fibre bundle18are shown in the dashed part ofFIG.5. When tension becomes large, the controller outputs a control signal, and the mechanism completes the following active actions. The output shaft of servo motor4rotates clockwise, driving electric actuator7to rotate clockwise around the axis of servo motor4. The electric actuator7drives the tension regulating rod17to contract at the same time. Due to the angle and length change of tension regulating rod17, swing frame5is driven to rotate counterclockwise around the spindle. Meanwhile, bracket6drives tension regulating roller10moves along guide rail15in the direction close to swing frame spindle14, the spring9is compressed which makes the distance between the tension regulating roller10and the front guide roller2and the back guide roller3decreasing, as shown in the solid part inFIG.5. Thus, reducing the tension and achieving the tension regulation of the fibre bundle18.

Conversely, when the tension of the fibre bundle18decreases during transmission, the servo motor4reverses, the tension regulating rod17stretches and drives the swing frame5to rotate clockwise, the tension regulating roller10moves away from the swing frame spindle14, and the distance between the front guide roller2and the back guide roller3increases to achieve an increase in the tension of the fibre bundle18. During the tension regulating roller10reciprocally moving along the guide15, the spring9between the bracket6and the spring substrate8is compressed or stretched, providing a cushioning effect for the movement of the mechanism, avoiding the vibration caused by the movement of the rigid structure which can affect the accuracy and achieving a stable and precise tension regulation by the rigid-flexible coupling mechanism.