A control method for trimming and forming of yarn bobbins on a doubling twisting machine

Abstract

The present invention discloses a control method for trimming and forming of yarn bobbins on a doubling twisting machine. The forming of the yarn bobbin is achieved by driving the yarn to reciprocate linearly by a traversing yarn guide head. The traversing stroke of the traversing yarn guide head is controlled by the doubling twisting machine control system according to the following relational expressions to achieve trimming and forming: current stroke = starting stroke - (starting stroke - ending stroke) * trimming ratio; trimming ratio = (current running time + current running time * trimming coefficient C) / (set running time + current running time * trimming coefficient C), trimming coefficient C = coefficient A * coefficient B, coefficient A = (starting stroke + ending stroke * 3) / [(starting stroke + ending stroke) * 4], coefficient B = (full bobbin diameter * 3 + empty tube diameter) / [(full bobbin diameter + empty tube diameter * 4)]. By setting and compensating the trimming ratio, it is ensured that the projection lines of the two ends of the yarn package on the cross-section of the yarn bobbin are straight edges, solving the problem that poor control of trimming and forming is likely to produce convex edges and concave edges.

Description

Technical Field

[0001] The present invention belongs to the technical field of yarn manufacturing equipment, and particularly relates to a trimming and forming control method for a double-twisting machine yarn bobbin. Background Art

[0002] As Figure 1 shown, the yarn bobbin 1 is composed of a bobbin tube 11 for winding yarn and a yarn package 12 wound on the bobbin tube. The yarn package is formed by winding yarn onto the yarn bobbin to form yarn loops arranged in a spiral manner along the axial direction of the yarn bobbin and stacked with yarn loops of different diameters in the radial direction of the yarn bobbin. End faces are formed at both ends of the yarn package, and trimming and forming are required during winding. When the yarn bobbin of the double-twisting machine is wound and formed, the yarn bobbin 1 is driven to rotate by friction of the friction roller 3 to wind into yarn loops. The traversing yarn guide head 4 drives the yarn 5 to reciprocate linearly along the axial direction of the yarn bobbin under the guidance of the traversing drive mechanism 3, and the yarn loops are formed into an axial spiral arrangement and a radial stack to achieve the forming of the yarn bobbin. The cross-sectional projection lines 121 at both ends of a well-formed yarn package should be straight side lines. Otherwise, it is easy to drop the yarn and generate end face mesh yarn, which affects the unwinding of the yarn in subsequent processes and leads to the scrapping of the yarn. The length and shape of the yarn bobbin are determined by the stroke and speed of the traversing yarn guide head. Since the diameter of the friction roller is constant and the rotational speed is constant, the linear speed of the yarn bobbin is constant. Therefore, the yarn bobbin also has a constant linear speed. Since the diameter of the yarn bobbin continuously expands, if the winding linear speed of the yarn is to be kept constant, it is necessary to continuously adjust the rotational speed of the yarn bobbin, and then the traversing stroke of the traversing yarn guide head also needs to be continuously adjusted, that is, trimming control is performed. If the trimming control is poor, the cross-sectional projection lines 121 at both ends of the yarn package are likely to generate convex side lines (as Figure 2 shown) or concave side lines (as Figure 3 shown). Summary of the Invention

[0003] The purpose of the present invention is to solve the defect that poor trimming control during the winding of the double-twisting machine yarn bobbin is likely to generate convex or concave edges, and to provide a trimming and forming control method for the double-twisting machine yarn bobbin that can ensure straight-line trimming and forming.

[0004] To this end, the present invention adopts the following technical solution: A method for controlling the trimming and forming of a yarn bobbin in a doubling twister. The yarn bobbin is driven to rotate and wind yarn by a friction roller with a constant rotational speed. The yarn is driven to reciprocate linearly along the axial direction of the yarn bobbin before being wound by a traversing yarn guide head to achieve the forming of the yarn bobbin. The traversing of the traversing yarn guide head is driven and guided by a traversing drive mechanism controlled by the doubling twister control system. It is characterized in that the doubling twister control system controls the traversing stroke of the traversing yarn guide head to achieve trimming and forming according to the relational expression formed by control parameters. The control parameters include the starting stroke, the ending stroke, the set running time, the current running time, the empty bobbin diameter, and the full bobbin diameter. The traversing stroke is divided into the current stroke and the starting stroke and the ending stroke. The traversing stroke of the traversing yarn guide head is controlled according to the relational expression "current stroke = starting stroke - (starting stroke - ending stroke) * trimming ratio". The trimming ratio is set and compensated according to the following relational expression: trimming ratio = (current running time + current running time * trimming coefficient C) / (set running time + current running time * trimming coefficient C), trimming coefficient C = coefficient A * coefficient B, coefficient A = (starting stroke + ending stroke * 3) / [(starting stroke + ending stroke) * 4], coefficient B = (full bobbin diameter * 3 + empty bobbin diameter) / [(full bobbin diameter + empty bobbin diameter * 4)]. The full bobbin diameter is the maximum diameter of the yarn bobbin when it is full, and the empty bobbin diameter is the diameter of the bobbin tube when there is no wound yarn. The set running time is the duration from the moment when a yarn bobbin starts to wind yarn from an empty bobbin to the moment when the yarn bobbin is full. Set running time = total length of yarn on the full bobbin / yarn winding speed. The yarn winding speed is determined by the rotational speed of the friction roller. The current running time is the duration from the moment when a yarn bobbin starts to wind yarn from an empty bobbin to the current moment during the winding process of the yarn bobbin. The starting stroke is a complete lateral movement distance of the traversing yarn guide head when the yarn bobbin starts to wind yarn from an empty bobbin. The ending stroke is a complete lateral movement distance of the traversing yarn guide head when the yarn bobbin is full. The current stroke is a complete lateral movement distance at the current moment during the winding process of the yarn bobbin.

[0005] The present invention can achieve the following beneficial effects: By limiting the current stroke through the trimming ratio and setting and compensating and trimming the trimming ratio according to the relational expression formed by control parameters such as the starting stroke, the ending stroke, the set running time, the current running time, the empty bobbin diameter, and the full bobbin diameter, it ensures that the projection lines of the two ends of the yarn package on the cross-section of the yarn bobbin are straight side edges, and there will be no forming defects such as convex edges and concave edges, which will not cause end face mesh yarn and edge collapse, and is beneficial for the unwinding of the yarn on the yarn bobbin in subsequent processes. Brief Description of the Drawings

[0006] Figure 1 It is a schematic structural diagram of the winding mechanism of a yarn bobbin doubling twister.

[0007] Figure 2 It is a diagram of a yarn bobbin with a forming defect of a convex edge.

[0008] Figure 3 It is a bobbin diagram that causes a defective concave edge forming situation. Specific implementation manners

[0009] The specific implementation manners of the present invention will be described in detail below with reference to the accompanying drawings. The described embodiments are only illustrative and explanatory of the present invention and do not constitute the sole limitation of the present invention.

[0010] As Figure 1 shown, the bobbin formed by the doubling winder winding consists of a bobbin tube 11 for winding yarn and a yarn package 12 wound on the bobbin tube. The doubling winder winding mechanism applying the method of the present invention includes a cradle (not shown in the figure) installed on the doubling winder frame for installing the bobbin tube and supporting the lifting of the bobbin, a friction roller 2 for driving the rotation of the bobbin by friction with the outer circumferential surface of the bobbin to realize yarn winding, a traverse yarn guide head 4, and a traverse driving mechanism 3 for driving and guiding the transverse linear reciprocating motion of the traverse yarn guide head 4. The motion of the traverse driving mechanism 3 is controlled by the control system of the doubling winder. The yarn 5 is driven by the traverse yarn guide head 4 to reciprocate along the axial direction of the bobbin. The rotational speed of the friction roller is constant, so the winding linear speed of the bobbin is also constant. As the diameter of the bobbin continuously increases, the rotational speed of the bobbin gradually decreases.

[0011] The doubling winder control system controls the traverse stroke of the traverse yarn guide head to achieve trimming forming according to the relational expression formed by the control parameters. The control parameters include the starting stroke, the ending stroke, the set running time, the current running time, the empty bobbin diameter, and the full bobbin diameter; the traverse stroke of the traverse yarn guide head is controlled according to the relational expression of "current stroke = starting stroke - (starting stroke - ending stroke) * trimming ratio"; the trimming ratio is set and compensated according to the following relational expression: trimming ratio = (current running time + current running time * trimming coefficient C) / (set running time + current running time * trimming coefficient C), trimming coefficient C = coefficient A * coefficient B, coefficient A = (starting stroke + ending stroke * 3) / [(starting stroke + ending stroke) * 4], coefficient B = (full bobbin diameter * 3 + empty bobbin diameter) / [(full bobbin diameter + empty bobbin diameter * 4)].

[0012] The above-mentioned full bobbin diameter is the maximum diameter of the bobbin when it is full, and the empty tube diameter is the diameter of the bobbin when there is no wound yarn; the set running time is the duration from the moment when a bobbin starts to wind yarn from an empty tube to the moment when the bobbin is full. The set running time = total length of yarn on the full bobbin / yarn winding speed. The yarn winding speed is determined by the rotational speed of the friction roller. The yarn winding speed = π * tube diameter * rotational speed of the friction roller. The total length of yarn on the full bobbin can be set artificially according to needs, or can be calculated and determined by dividing the net weight of the yarn obtained by subtracting the weight of the tube from the set weight of the bobbin by the weight of the yarn per unit length; the current running time is the duration from the moment when a bobbin starts to wind yarn from an empty tube to the current moment during the winding process of the bobbin, and is automatically counted by the control system starting from when a bobbin starts to wind; the starting stroke is a complete lateral movement distance of the traverse guide when the bobbin starts to wind yarn from an empty tube, the ending stroke is a complete lateral movement distance of the traverse guide when the bobbin is full, and the current stroke is a complete lateral movement distance where the bobbin is located at the current moment during the winding process of the bobbin.

Claims

1. A control method for trimming and forming of a double-twisting machine yarn bobbin. The yarn bobbin is driven to rotate and wind yarn by a friction roller with a constant rotational speed. The yarn is driven to reciprocate linearly along the axial direction of the bobbin before being wound by a traversing yarn guide head to achieve the forming of the bobbin. The traversing of the traversing yarn guide head is driven and guided by a traversing drive mechanism controlled by the double-twisting machine control system. It is characterized in that: The double-twisting machine control system controls the traversing stroke of the traversing yarn guide head to achieve trimming and forming according to the relational expression formed by control parameters. The control parameters include the starting stroke, the ending stroke, the set running time, the current running time, the empty bobbin diameter, and the full bobbin diameter. The traversing stroke is divided into the current stroke, the starting stroke, and the ending stroke. The traversing stroke of the traversing yarn guide head is controlled according to the relational expression of "current stroke = starting stroke - (starting stroke - ending stroke) * trimming ratio". The trimming ratio is set and compensated according to the following relational expression: trimming ratio = (current running time + current running time * trimming coefficient C) / (set running time + current running time * trimming coefficient C), trimming coefficient C = coefficient A * coefficient B, coefficient A = (starting stroke + ending stroke * 3) / [(starting stroke + ending stroke) * 4], coefficient B = (full bobbin diameter * 3 + empty bobbin diameter) / [(full bobbin diameter + empty bobbin diameter * 4)]. The full bobbin diameter is the maximum diameter of the bobbin when it is full, and the empty bobbin diameter is the diameter of the bobbin tube when there is no wound yarn. The set running time is the time required for a bobbin to wind yarn from an empty bobbin to a full bobbin, set running time = total length of yarn on the full bobbin / yarn winding speed. The yarn winding speed is determined by the rotational speed of the friction roller. The current running time is the time elapsed from the moment when a bobbin starts to wind yarn from an empty bobbin to the current moment during the winding process of the bobbin. The starting stroke is a complete lateral movement distance of the traversing yarn guide head when the bobbin starts to wind yarn from an empty bobbin, the ending stroke is a complete lateral movement distance of the traversing yarn guide head when the bobbin is full, and the current stroke is a complete lateral movement distance where the bobbin is located at the current moment during the winding process.

2. A control method for trimming and forming of a double-twisting machine yarn bobbin according to claim 1. It is characterized in that: The yarn winding speed is determined by the rotational speed of the friction roller, and the yarn winding speed = π * bobbin tube diameter * rotational speed of the friction roller.

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