Yarn cleaner for a workstation of a textile machine with a thread guide element

Description

[0001] The invention relates to a yarn cleaner for a workstation of a textile machine with at least one thread guide element.

[0002] The winding of a thread typically occurs at very high thread speeds, resulting in undesirably high material removal in the area of ​​the surfaces of the textile machine adjacent to and / or in contact with the thread. This applies, for example, to a thread guide channel of a yarn monitoring and / or yarn processing unit, in particular a yarn cleaner, on a textile machine producing winding bobbins. Such a yarn cleaner with the features of claim 1 is known, for example, from WO 2013 / 131198 A1.

[0003] Due to its high speed of movement, its structure, and the fiber ends protruding from the thread surface, the thread generates a suction effect and, consequently, an airflow along its direction of movement, which is governed by Bernoulli's principle. Therefore, even small variations in the distance between surfaces and the moving thread, and especially variations in the width of a thread guide channel, lead to pressure differences and, as a result, to undesirable turbulence, which in turn leads to increased material loss over time. This effect is particularly pronounced at the inlet and / or outlet of a thread guide channel.

[0004] Furthermore, this effect is more pronounced the narrower the yarn guide channel, making a particularly wide yarn guide channel preferable. However, for numerous applications, such as monitoring at least one yarn parameter and / or efficient yarn processing, a particularly narrow yarn guide channel is preferred. Therefore, to ensure the proper functioning of a yarn monitoring and / or yarn processing unit, especially a yarn cleaner, a narrow yarn guide channel is necessary, and consequently, increased material removal due to undesirable turbulence in prior art devices cannot be avoided.

[0005] Furthermore, such turbulence not only leads to material loss on the yarn monitoring and / or processing unit, but also to a deterioration in the quality of the yarn itself, as the turbulence directly affects its surface and can pull out additional fiber ends. Moreover, the turbulence exerts radial forces on the rapidly moving yarn, which can alter its path. This significantly hinders yarn monitoring and can also lead to contact between the yarn and a surface of the yarn monitoring and / or processing unit, particularly the yarn cleaner, potentially resulting in further deterioration in quality or even damage to the yarn.

[0006] These negative effects are particularly pronounced in the area of ​​thread guiding elements, which are typically located at the entrance and / or exit of a thread guiding channel of a yarn monitoring and / or yarn processing unit, especially a yarn cleaner.

[0007] The invention is therefore based on the objective of providing a thread guide element that significantly reduces material removal at a yarn monitoring and / or yarn processing unit, in particular a yarn cleaner, avoids a deterioration of the quality of the thread or yarn in the area of ​​the thread guide element and enables an improvement in yarn monitoring and / or yarn processing as well as an increase in yarn speed during winding.

[0008] The problem is solved according to the invention by a yarn cleaner for a workstation of a textile machine according to claim 1. Advantageous embodiments are specified in the dependent claims.

[0009] The yarn cleaner according to the invention for a workstation of a textile machine has a yarn guide channel with a yarn inlet for feeding the yarn and a yarn outlet for discharging the yarn, as well as at least one yarn guide element. The yarn guide element has a yarn guide opening for guiding a yarn laterally or orthogonally to a yarn path, a yarn receiving opening for introducing the yarn into the yarn guide opening, and an airflow compensation opening for equalizing the static pressure on both sides of the yarn guide element and, in particular, within a yarn guide channel, and / or for generating a laminar airflow at least on one

[0010] The side of the thread guide element is exposed at least in the area of ​​the guided thread.

[0011] The inventors have recognized that by incorporating an airflow equalization opening to balance the static pressure on both sides of the yarn guide element and / or to generate a laminar airflow at least on one side of the yarn guide element, at least in the yarn area, a significant reduction in material removal by the yarn cleaner, hereinafter also referred to as the yarn monitoring and / or yarn processing unit, and simultaneously a significant increase in yarn quality can be achieved in a simple manner. Furthermore, the yarn follows a particularly consistent yarn path, thereby enabling a considerable improvement in yarn monitoring and / or yarn processing as well as an increased yarn speed.

[0012] A thread guide element, also known as an "eyelet," is a component or assembly that guides a thread, particularly a thread moving rapidly along its central longitudinal axis, in at least one spatial direction; that is, it limits the position of the thread in at least one direction and preferably keeps it constant. Preferably, the thread is guided, particularly by means of the thread guide opening, at least on two sides, and more preferably at least on three sides, and most preferably exactly on three sides, particularly radially to the thread direction or orthogonally to the thread path. Furthermore, the thread is preferably guided in direct contact with a part of the thread guide element, particularly by means of a smooth surface, and more preferably by means of a thread guide opening.

[0013] The yarn cleaner is designed, for example, to detect the presence and / or absence of a thread. Additionally, the yarn cleaner can preferably detect at least one yarn parameter and / or is preferably designed to detect a yarn defect.

[0014] The thread is guided through the thread guide element by means of a thread guide opening, which can be of any shape, for example, as an opening, a channel open on one side, a gap, a slot, or the like. The thread guide opening can surround the thread on multiple sides or only over a portion of its circumference. Preferably, the thread guide opening has an open shape so that the thread can be inserted laterally into the thread guide opening via the thread receiving opening without cutting the thread and / or with a central section. Preferably, the thread guide opening is arranged in the thread guide element. Particularly preferably, the thread guide opening is a narrow passage or a gap, wherein the width of the thread guide opening is preferably less than 5 mm, more preferably less than 3 mm, and most preferably less than 2 mm.

[0015] The yarn path is the path of the moving yarn and preferably follows essentially unchanged in the yarn direction and / or along a constant path and / or is defined by the yarn guide element and, in particular, by the yarn guide opening. The yarn path, especially between two yarn guide elements of the yarn cleaner, is particularly preferably linear. Most preferably, the yarn path between the yarn inlet and outlet of the yarn cleaner runs along a straight line.

[0016] The yarn cleaner can be of any design and may be configured to monitor the passing yarn and / or its parameters and / or to process the yarn, in particular to cut out defective sections. Accordingly, the yarn cleaner preferably has at least one unit for monitoring and / or processing the yarn between the yarn inlet and outlet, and particularly within the yarn guide channel. In particular, the yarn cleaner may include a cutting device to remove detected yarn defects and / or yarn flaws, i.e., to cut off a defective section. The yarn cleaner is preferably designed for installation on a textile machine, especially on a winding machine and / or a rewinding machine.

[0017] An airflow equalization opening is understood to be at least or exactly one opening, at least or exactly one passage, or at least or exactly one channel that allows pressure equalization between two areas arranged on either side of the airflow equalization opening and / or a gas flow or volume flow between these areas. The airflow equalization opening can be formed by a single component or by the surfaces or sections of several components. Preferably, the airflow equalization opening is arranged entirely within a component and / or formed entirely by a component, which particularly preferably also includes the thread guide opening. Most preferably, the airflow equalization opening is arranged adjacent to the thread guide opening.

[0018] One of the functions of the airflow equalization opening can be to generate a laminar airflow on one side of the yarn guide element, particularly inside the yarn monitoring and / or yarn processing unit. Generating a laminar airflow initially means simply reducing a turbulent airflow, whereby the generated airflow is preferably predominantly laminar. However, the laminar airflow may still contain a small turbulent component, which is particularly preferably as small as technically feasible. Preferably, the turbulent component is less than 50%, more preferably less than 30%, very preferably less than 20%, and particularly preferably less than 10%.The side of the yarn guide element where the laminar airflow is generated is preferably located behind the yarn guide element when it is arranged at a yarn inlet of the yarn monitoring and / or yarn processing unit, and preferably in front of the yarn guide element when it is arranged at a yarn outlet. Generally, the laminar airflow is preferably generated in a measuring channel that defines a sensor area of ​​the yarn monitoring and / or yarn processing unit, and particularly preferably within the yarn guide channel itself. The airflow can, in principle, be any gas stream, which may consist of ambient air or have a different gas composition.

[0019] The thread guide channel can surround the thread within the yarn cleaner section by section, on multiple sides, or completely on all sides, or it can surround the thread only around part of its circumference and be open the rest. Preferably, the thread guide channel is open on at least one side, and particularly preferably exactly on one side along the thread path, for example, to facilitate easy insertion of the thread.

[0020] A preferred embodiment of the thread guide element provides that the thread guide opening is fork-shaped with two thread guide sections between which the thread is guided and / or which converge in a preferably U-, C-, or V-shaped thread guide area. Preferably, the thread guide sections run parallel to each other at least partially and / or maintain a constant distance from each other. Furthermore, preferably, the two thread guide sections are mirror images of each other and / or arranged mirror images of each other on the thread guide element. Preferably, the thread path runs exclusively within the thread guide area, and particularly preferably within the portion of the U-, C-, or V-shaped area in which the thread is guided substantially to at least 90°, particularly preferably to at least 135°, and most preferably to 180° of its circumference.

[0021] In an advantageous embodiment of the thread guide element, the airflow compensation opening completely penetrates the thread guide element in the thread path direction and / or is spaced apart from and / or adjacent to the thread guide opening, thereby enabling particularly efficient pressure equalization and / or facilitating the generation of a laminar airflow in the area of ​​the thread path. Preferably, the thread guide opening and the airflow compensation opening are located at least on one side of the thread guide element and are particularly preferably completely separate from each other. It is especially preferred that the airflow compensation opening is designed and / or arranged such that the thread cannot enter the airflow compensation opening.In particular, a design of the thread guide element is preferred in which the airflow compensation opening is located on a side of the thread guide opening facing away from the thread receiving opening, preferably in a front view of the thread guide element below the U- or V-shaped thread guide area in which the two thread guide sections meet, and / or centrally in relation to the thread guide opening.

[0022] The airflow compensation opening, in particular the airflow compensation opening facing the outside of the yarn monitoring and / or yarn processing unit, can in principle be designed and shaped as desired. However, a preferred configuration of the yarn guide element is one in which the airflow compensation opening at an inlet side to the yarn monitoring and / or yarn processing unit is round or elliptical, particularly with the largest possible opening. Alternatively or additionally, the airflow compensation opening at an outlet side of the yarn from the yarn monitoring and / or yarn processing unit can also be round or elliptical in the manner described above. The preferred round or elliptical configuration reduces flow resistance.

[0023] To control the characteristics of the airflow on the yarn exit side of the yarn guide element, and particularly in the yarn guide channel of the yarn monitoring and / or yarn processing unit, it is preferred that the yarn guide element extends over a longer section along the yarn path than would be necessary for mere yarn guidance. In an advantageous embodiment of the yarn guide element, the length of the yarn guide opening in the yarn direction or along the yarn path is at least between 0.75 mm and 5 mm, preferably at least between 1 mm and 3 mm, and particularly preferably at least between 1 mm and 2 mm. Alternatively or additionally, the length of the yarn guide opening in the yarn direction or along the yarn path is at least 1.5 times longer than the width of the yarn guide opening, preferably at least 2.0 times longer, particularly preferably at least 2.5 times longer, and most preferably at least 3.0 times longer.The width of the thread guide opening is defined as the distance between the two thread guide sections, particularly in a region of a parallel arrangement and / or in the thread-guiding area. The length of the thread guide opening is correspondingly its extent along the thread path or parallel to the thread path.

[0024] According to the invention, the thread guide element is designed in two successive sections in one direction of the thread path, wherein a first section is formed for thread guidance and a second section for modifying the airflow. Accordingly, the thread guide element has a thread guide section extending along the thread path and an adjacent flow-stabilizing section, in which no further thread guidance takes place. Accordingly, the thread in the flow-stabilizing section preferably has no contact with the thread guide sections, and particularly preferably, the thread in the flow-stabilizing section has no contact with any surface of the thread guide element.The flow-stabilizing surface can, in principle, separate the airflow compensation opening from an area of ​​the thread in the thread guide element, or alternatively, the thread can be guided through an area that is at least partially surrounded by one or more flow-stabilizing surfaces.

[0025] To generate a particularly effective laminar airflow, a preferred embodiment of the thread guide element provides that the airflow compensation opening is formed on a side of the thread guide section facing away from the thread receiving opening and has, at least in the extension area of ​​the thread guide section along the thread direction, preferably the entire airflow compensation opening, a flow-stabilizing surface optimized by computational fluid dynamics (CDF) calculations in order to generate a laminar airflow in the flow-stabilizing section and / or in an adjacent or neighboring area. In particular, a surface of the thread guide opening without edges and / or without angles greater than or equal to 90° is preferred.

[0026] Accordingly, the airflow compensation opening in the area of ​​the thread guide section, and preferably extending over the entire thread guide section, has a surface angled relative to the thread direction by an angle of between 25° and 60°, preferably between 35° and 55°, particularly preferably between 40° and 50°, and most preferably by 45°. This angled design serves to form an angled ventilation channel, by means of which static equalization can be achieved near the base of an adjacent sensor area. This allows the pressure gradient within the sensor area, which is preferably limited by a measuring channel associated with the sensor, to be kept as small as possible.

[0027] According to a preferred embodiment, the airflow compensation opening comprises an airflow outlet plane whose normal vector points in a direction away from the thread receiving opening, including an angle of 0° or greater with the thread path. This ensures a more effective guarantee of the laminar flow to be generated in the area of ​​the sensor base.

[0028] In one preferred embodiment, the yarn guide element is further equipped with a positioning aid for positioning the yarn guide element on a yarn monitoring or yarn processing unit on a side of the yarn guide element facing away from the yarn receiving opening and / or the airflow compensation opening. This allows the yarn guide element to be positioned more easily and precisely, particularly at the inlet and / or outlet of the sensor area of ​​the yarn monitoring or yarn processing unit. For example, the positioning aid can be designed as a recess for receiving a correspondingly shaped projection, such as a flange, thereby enabling precise placement at an inlet or outlet of a yarn guide channel of the yarn monitoring or yarn processing unit. Furthermore, the positioning aid can preferably be designed to secure the yarn guide element to the inlet or outlet of the yarn monitoring or yarn processing unit by means of clamping, locking, or screwing.To secure the outlet of the thread guide channel.

[0029] In an advantageous embodiment of the yarn cleaner for a workstation of a textile machine, a yarn guide element according to the invention is arranged at each inlet and outlet of the yarn guide channel. Preferably, both or all yarn guide elements of the yarn cleaner are identical and / or mirror-symmetrical to each other. If the yarn guide elements are identical, it is preferred that the two yarn guide elements are arranged on the yarn cleaner with identical sides facing each other.

[0030] An embodiment of a thread guide element according to the invention is described in more detail below with reference to the drawings. These show: Fig. 1: A schematic front view of a thread guide element with the entry side for a thread; Fig. 2: A schematic sectional view of two of a Figure 1The illustrated thread guide element and Fig. 3 a perspective schematic view of a yarn cleaner.

[0031] One in the Figure 1 A schematically depicted thread guide element 1 for a yarn cleaner 9 at a workstation of a textile machine is formed in one piece and has two fork-shaped thread guide sections 4 arranged together, which converge in a V-shape from the direction of a thread receiving opening 19 into a thread guide area 5. The two thread guide sections 4 form a gap that serves as a thread guide opening 2, open on one side. Within the thread guide area 5 of the thread guide opening 2, a thread can be guided at high speed and protected against lateral deviations of the thread path.

[0032] The thread guide opening 2 has smooth surfaces aligned in the direction of thread travel, allowing the thread to be guided at high speed with minimal adhesion. However, the fibers protruding from the surface of the rapidly moving thread create a suction effect, resulting in an airflow in and behind the thread guide element 1 and a pressure difference in front of and behind the thread guide element 1.

[0033] To compensate for this static pressure difference, the thread guide element 1 has an airflow compensation opening 3 with an elliptical opening below the thread guide opening 2, wherein the airflow compensation opening 3 completely penetrates the thread guide element 1 in the direction of the thread path.

[0034] Figure 2In this context, a schematic sectional view shows two thread guide elements 1, wherein one thread guide element 1 is located on the input side and the other thread guide element 1 on the output side of a sensor area of ​​a yarn cleaner 9 (not shown) running between the two thread guide elements 1.

[0035] To avoid turbulent airflow on the thread exit side of the thread guide element 1 and instead generate a laminar airflow, the respective thread guide element 1 has a flow-stabilizing section 6 adjacent to and directly connected to a thread guide section 7 along the thread path. The thread guide element 1, the thread guide section 7, and the flow-stabilizing section 6 are formed integrally.

[0036] The flow-stabilizing section 6 has at least one flow-stabilizing surface 8, which has been optimized by computational fluid dynamics to generate a particularly laminar airflow in and behind the thread guide element 1. The thread guide element 1 has a flow-stabilizing surface 8 in the thread guide section 7, which runs at an angle of approximately 45° to the thread or the thread path and leads to a deflection of the resulting airflow.

[0037] Figure 3Figure 1 shows a perspective schematic view of an embodiment of a yarn cleaner 9 with a yarn guide element 1 as described above. The yarn guide element 1 is arranged along a yarn path on the inlet side to a sensor area 10 of the yarn cleaner 9. Alternatively or additionally, according to a further embodiment, such a yarn guide element 1 can be arranged along the yarn path on the outlet side of the sensor area 10.

[0038] The yarn cleaner 9 according to the illustrated embodiment comprises a three-part housing body 11 with a first and second housing part 12, 13, each for receiving a sensor that monitors the yarn crossing the sensor area 10, which is limited at the inlet by the yarn guide element 1. For example, one of the first and second housing parts 12, 13 can have a capacitive sensor and the other housing part an optical sensor for monitoring different yarn parameters. The third housing part 14 of the housing body 11 is arranged along the yarn path adjacent to the second housing part 13, wherein the third housing part 14 partially encloses a cutting device with a cutting blade 15 that crosses the yarn path of the yarn cleaner 9 and includes a stop 16 for the cutting blade 15 for cutting an intervening yarn (not shown). Reference symbol list

[0039] 1 Thread guide element 2 Thread guide opening 3 Airflow compensation opening 4 Thread guide section 5 V-shaped thread guide area 6 Flow-stabilizing section 7 Thread guide section 8 Flow-stabilizing surface 9 Yarn cleaner 10 Sensor area 11 Housing body 12 First housing part 13 Second housing part 14 Third housing part 15 Cutting blade 16 Stop 17 Recess / Positioning aid 18 Flange 19 Thread pickup opening

Claims

1. Yarn clearer (9) for a workstation of a textile machine, with - a thread guide channel with a thread inlet for feeding the thread and a thread outlet for discharging the thread, - at least one thread guide element (1) with - a thread guide opening (2) for guiding a thread laterally to a thread path, - a thread pick-up opening (19) for inserting the thread into the thread guide opening (2), - an air flow equalisation opening (3) for equalising the static pressure on both sides of the thread guide element (1) and / or for generating a laminar air flow on one side of the thread guide element (1) at least in the area of the guided thread, - a thread guide section (7) extending along the thread running direction, as well as - a flow-calming section (6) extending along the thread running direction and adjacent to the thread guide section (7), in which no thread guidance takes place, characterized in that the air flow equalisation opening (3) has a flow-calming surface (8) extending over the thread guide section (7) and positioned at an angle between 25° and 60° with respect to the thread running direction.

2. Yarn clearer (9) according to claim 1, characterized in that the thread guide opening (2) is formed in a forked shape with two thread guide sections (4) between which the thread is guided and / or which converge in a U- or V-shaped thread guide area (5).

3. Yarn clearer (9) according to claim 1 or 2, characterized in that the air flow equalisation opening (3) completely penetrates the thread guide element (1) in the thread running direction and / or is arranged spaced apart from and / or adjacent to the thread guide opening (2).

4. Yarn clearer (9) according to at least one of the preceding claims, characterized in that the air flow equalisation opening (3) is arranged on a side of the thread guide opening (2) facing away from the thread pick-up opening (19), in particular centrally with respect to the thread guide opening (2).

5. Yarn clearer (9) according to at least one of the preceding claims, characterized in that the air flow equalisation opening (3) is round or elliptical in its opening plane.

6. Yarn clearer (9) according to at least one of the preceding claims, characterized in that the length of the thread guide opening (2) along the thread path is at least between 1 mm and 3 mm and / or the length of the thread guide opening (2) along the thread path is longer than the width of the thread guide opening (2) by at least a factor of 2.0.

7. Yarn clearer (9) according to one of the preceding claims, characterized in that the air flow equalisation opening (3) is formed on a side of the thread guide section (7) facing away from the thread pick-up opening (19) and has, at least in the extension region of the thread guide section (7) along the thread running direction, a flow-calming surface (8) optimised in particular by computational fluid mechanics calculations, in order to generate a laminar air flow in the flow-calming section (6) and / or in a region adjacent thereto.

8. Yarn clearer (9) according to one of the preceding claims, characterized in that the air flow equalisation opening (3) has a flow-calming surface (8) extending over the thread guide section (7) and positioned at an angle between 40° and 50° with respect to the thread running direction.

9. Yarn clearer (9) according to at least one of the preceding claims, characterized in that the air flow equalisation opening (3) has an air flow outlet plane, the normal vector of which points in a direction away from the thread pick-up opening (19) confining an angle with the thread path.

10. Yarn clearer (9) according to at least one of the preceding claims, characterized in that a positioning aid (17) for positioning the thread guide element (1) on a yarn monitoring or yarn processing unit is provided on a side of the thread guide element (1) facing away from the thread pick-up opening (19) and / or the air flow equalisation opening (3).

11. Yarn clearer (9) according to one of the preceding claims, characterized in that a thread guide element (1) is arranged at an inlet and / or at an outlet of the thread guide channel in each case.

12. Yarn clearer (9) according to one of the preceding claims, characterized in that the thread guide channel delimits at least one sensor range (10) of a sensor surrounded by the yarn clearer (9) for detecting defined parameters of the thread running through the thread guide channel, a normal vector of an air flow outlet plane of the air flow equalisation opening (3) pointing in the direction of an edge area of the sensor range (10) opposite the thread pick-up opening (19).