Air spinning machine and drawing frame unit for a spinning station of an air spinning machine

Abstract

The invention relates to an air spinning machine and a drafting unit for a spinning station of an air spinning machine for producing a thread or roving from a supplied fiber strip, with at least one output roller pair consisting of an output upper roller on a load carrier and a driven output lower roller on a lower roller carrier and forming a clamping line, and a bearing element arranged on the lower roller carrier for movably supporting an air spinning nozzle.In order to provide a drafting unit for a spinning station of an air spinning machine and an air spinning machine which has a reliable pivotable air spinning nozzle that can be easily detached from the lower roller carrier if necessary, it is provided that the lower roller carrier includes a bearing element having a free end, via which the air spinning nozzle can be received, wherein the bearing element forms a pivot axis for pivoting the air spinning nozzle between an operating position and a second position spaced apart from it, wherein the bearing element is connected to the lower roller carrier with a section spaced away from the free end.

Description

[0001] The invention relates to a drafting unit for a spinning station of an air-jet spinning machine for producing a thread or roving from a supplied fiber sliver, with at least one pair of output rollers consisting of an output upper roller on a load carrier and a driven output lower roller on a lower roller carrier and forming a clamping line, and a bearing element arranged on the lower roller carrier for movably supporting an air spinneret.

[0002] Drafting units for textile machines are known in a wide variety of designs from the prior art. They are used to draw or draft a fiber sliver, thereby reducing the fiber's cross-section. During drafting, the fibers must be shifted against each other as evenly as possible to achieve the most uniform fiber sliver possible.

[0003] To draw the fiber sliver, the drafting units typically have several consecutively arranged pairs of rollers that clamp the fiber sliver running between them. A roller pair typically consists of a driven lower roller mounted on a lower roller support and a top roller mounted on a pivoting load carrier, which is rotatably supported by the load carrier. Drafting of the fiber sliver is achieved by increasing the peripheral speed from roller pair to roller pair in the direction of transport of the fiber sliver through the drafting unit, which is determined by the direction of rotation of the roller pairs.

[0004] During air-jet spinning using a spinning machine to spin a yarn, the fiber sliver is typically drawn by the drafting unit according to the desired yarn count and then fed to an air-jet spinneret of an air-jet spinning device. Within the air-jet spinning device, the outer fibers of the fiber sliver are wound around the inner core fibers of the fiber sliver by means of a swirling air flow generated by the air-jet spinneret, thereby forming the wrapping fibers that determine the desired thread strength. The thus formed thread is finally drawn off via a take-off channel of the air-jet spinning device and wound, for example, onto a tube.

[0005] In known drafting systems, the air-jet spinneret is arranged on the lower roller support of the drafting system unit, downstream of the output roller pair of the drafting system unit in the transport direction of the fiber sliver. To arrange the air-jet spinneret on the lower roller support, it is known to use holders connected to and adapted to the lower roller support, on which the air-jet spinneret is pivotably mounted so that it can be adjusted between an operating position, in which the fiber sliver emerging from the output roller pair is conveyed into the air-jet spinneret, and a maintenance position. In the maintenance position, for example, it is possible to easily clean the area between the spinneret and the output roller pair.In order to completely remove the spinneret from the lower roller support, for example, for maintenance work, the holders known from the prior art require the spinneret and the attached spinnerets to be removed from the lower roller support, for example by loosening the corresponding screw connections that secure the holder to the lower roller support. The air spinneret is usually pivotably mounted on the holder via two opposing bearing points, which also have a high positional tolerance.

[0006] Drafting units according to the prior art are known from EP 1 431 433 A1, EP 2 752 513 A1 and JP 2009 068126 A.

[0007] In air-jet spinning using a roving frame to spin a roving, the fiber sliver produced, for example, by a draw frame, the so-called draw frame sliver, is fed to the roving frame. The roving frame comprises an air-jet spinning device, such as that described above, wherein the dimensions and flow conditions of the air-jet spinning device for producing the roving are suitably adapted to those of an air-jet spinning device for producing a thread. The mode of operation of such an air-jet spinning device of the roving frame for producing a roving is similar to that of the air-jet spinning devices of air-jet spinning frames for producing a thread.

[0008] Based on this, the invention is based on the object of providing a drafting unit for a spinning station of an air-jet spinning machine and an air-jet spinning machine which has a reliable pivotable air-jet spinneret which can be detached from the bottom roller support in a simple manner, in particular without tools, if necessary.

[0009] The invention solves the problem by a drafting unit having the features of claim 1 and by an air-jet spinning machine having the features of claim 9. Advantageous developments of the drafting unit are specified in the dependent claims 2 to 8.

[0010] According to a preferred embodiment, the air-jet spinning machine can be a spinning machine which is designed to produce a thread which can be wound onto a winding bobbin tube to form a winding bobbin, in particular a so-called cross-wound bobbin.

[0011] According to a further preferred embodiment, the air-jet spinning machine can be a roving machine for producing a roving, as described above, for example. In such a roving machine, the air-jet spinning device is designed such that the produced roving has a reversible protective twist. Such a reversible protective twist is known to be characterized by the fact that the roving remains draftable for further processing, such as on the ring spinning machine, wherein the introduced twist can be undone again if necessary. The reversible protective twist is usually achieved such that the fiber sliver fed to the air-jet spinning device is at least partially imparted a true twist by the air-jet spinning device.This means that at least some of the fibers of the supplied fiber sliver receive a true twist, i.e. a rotation, during the air spinning process, which is achieved by means of the air flow generated in the air spinning device.

[0012] A characteristic of the drafting system unit according to the invention is that the lower roller support comprises a bearing element having a free end, via which the air spinneret can be received and which forms a pivot axis for pivoting the air spinneret between an operating position and at least one second position spaced therefrom, wherein the bearing element is connected to the lower roller support with a section spaced from the free end. With reference to the operating position, which defines the first position, the second position is a position further away from the output roller than the operating position. For example, the second position can define a maintenance position in which maintenance activities can be carried out as described above by way of example. Alternatively, the second position can be a position different from the maintenance position.In particular, the second position can be between the operating position and the maintenance position, or a position further away from the output roller relative to the maintenance position. In the latter preferred case, the second position is provided downstream of both the operating position and the maintenance position in a direction emanating from the output roller. The second position can furthermore preferably define an end position for the pivotable air spinneret, in which the air spinneret can have the greatest achievable distance from the output roller.

[0013] The section for connection to the lower roller support can preferably be an end of the bearing element opposite the free end. This allows the bearing element to be designed in a defined and cost-effective manner. Alternatively, the section can be a section located between the free end and a further, in particular free, end of the bearing element opposite it. This facilitates further arrangement options for additional components on the bearing element if required. The connection of the bearing element to the lower roller support via the section is fundamentally freely selectable. According to a preferred embodiment, the lower roller support has a fastening receptacle designed to receive the section of the bearing element. Further preferably, at least the fastening receptacle or the section of the bearing element is designed to enable a stationary fixation of the bearing element to the lower roller support.This can be done, for example, by means of a screw fastening or clamping fixation, which is more preferably spring-loaded.

[0014] The inventive design of the drafting system unit makes it possible to easily arrange the air spinneret on the lower roller support or to remove it from it. To arrange the air spinneret on the lower roller support, it only needs to be pushed over the free end onto the bearing element with an opening adapted to the free end of the bearing element. Removing the air spinneret from the lower roller support can in turn be achieved by simply sliding the air spinneret down from the bearing element over the free end. The bearing element, which is free at one end, thus allows easy assembly and disassembly of the air spinneret on the lower roller support and also offers the possibility of pivoting the air spinneret about the pivot axis formed by the bearing element between the operating position and the second position spaced therefrom.Furthermore, a one-sided mounting of the bearing element on the lower roller support allows a particularly precise and play-free alignment of the swivel axis relative to the lower roller support.

[0015] To determine the position of the air spinneret in the direction of its being pushed onto the bearing element, particularly along the pivot axis, a preferred embodiment of the invention provides that the bearing element has a stop element in a section opposite the free end. The use of a stop element, for example in the form of a shoulder or flange that preferably at least partially or more preferably completely surrounds the pivot axis or the bearing element, allows precise positioning of the air spinneret in its direction of being pushed onto the bearing element, so that the air spinneret can be optimally arranged relative to the pair of output rollers in the operating position. Separate alignment is therefore unnecessary.

[0016] According to a further preferred embodiment of the invention, the air spinneret is securely fixed to the bearing element. The positional securing of the air spinneret can in principle be freely selectable. In particular, to secure the position of the air spinneret on the bearing element, the bearing element is designed in the region of its free end to accommodate a position-securing element. The use of a position-securing element, for example via a screw fastening or a clamping fixation, which can more preferably be spring-loaded, reliably ensures that the air spinneret does not accidentally slip off the bearing element. For example, the position-securing element can be a screw that can be screwed onto the free end of the bearing element, a snap ring that can be arranged on the free end of the bearing element, or a pressure piece, in particular a spring-loaded one.Spring-loaded pressure pieces are well known and offer the advantage over a conventional clamping screw in that the tip of the pressure piece is designed to be spring-loaded and movable. As soon as the spring force acting on the tip of the pressure piece, which acts as a clamping force, is overcome, the tip moves towards the pressure piece or into the pressure piece, whereby the component held by the spring-loaded pressure piece or the air spinneret can be moved on the bearing element. Alternatively or additionally, the bearing element and a carrier carrying the air spinneret, which can be pushed onto the bearing element, can preferably have a tongue and groove locking mechanism, similar to the preferred embodiment with the spring-loaded pressure piece, which engages or disengages along the pushing-on direction of the air spinneret when a defined force along the pushing-on direction is overcome.In contrast to the spring-loaded pressure piece, no spring-loaded pressure element such as the tip of the spring-loaded pressure piece is provided. Alternatively or additionally, a locking lever can be provided, which is arranged transversely to the direction of insertion on the lower roller support so as to be rotatable. This locking lever secures the air spinneret after positioning on the bearing element to prevent it from moving counter to the direction of insertion. The preferred use of a snap ring as a position-securing element is characterized by the fact that it ensures reliable positional securing of the air spinneret on the bearing element and, if necessary, enables quick and easy removal, so that the air spinneret can then be easily removed from the bearing element.

[0017] The design of the bearing element forming the pivot axis for the air spinneret is fundamentally freely selectable. For example, it can also be designed integrally with the lower roller support. According to a preferred embodiment of the invention, the bearing element is arranged on a pivot axis support of the lower roller support. This preferred embodiment of the invention offers the possibility of removing the bearing element from the lower roller support if necessary and replacing it with a new bearing element, for example to enable the use of alternative air spinnerets on the drafting system unit. According to a particularly preferred embodiment of the invention, the bearing element is formed by a bearing bolt that is held stationary by the pivot axis support and, more preferably, is pressed or screwed into the pivot axis support.The use of a bearing pin, particularly one that is pressed or screwed in, ensures high positional stability with very low bearing tolerance, thus ensuring particularly reliable, optimal positioning of the air spinneret relative to the fiber sliver emerging from the output roller pair. Alternatively, the bearing pin can also be attached to the lower roller support or the pivot axis support using other fastening methods, such as a clamping or locking device, a bayonet lock, or similar. The fastening method selected should always be one that allows for a fixed mounting of the bearing pin on the lower roller support or the pivot axis support.

[0018] The arrangement of the bearing element relative to the pair of output rollers is also fundamentally freely selectable. According to a preferred embodiment of the invention, the bearing element is arranged such that the air spinneret can be pivoted between the operating position and at least the second position along a direction of movement that runs transversely to the axis of rotation of the output roller, more preferably orthogonally. Further preferably, the bearing element is arranged such that the air spinneret can be pivoted tangentially to the lower output roller between the operating position and the second position. According to this further preferred embodiment of the invention, the pivot axis runs parallel to the clamping line of the pair of output rollers and the pivot axis, the axis of rotation of the lower output roller and the axis of rotation of the upper output roller lie in a common plane, i.e., they span a common plane. Due to the preferred orIn a further preferred embodiment of the invention, the spinneret can be displaced from the operating position at least into the second position, which can constitute the maintenance position and / or an end position for the pivotable air spinneret that differs from the operating position, in a direction of movement that facilitates the dissolution of thickenings in the yarn. In particular, the further preferred embodiment of the tangential pivoting of the air spinneret relative to the output roller contributes to further improved dissolution of thickenings in the yarn.

[0019] To facilitate the assembly of the air spinneret to the bearing element, according to a further preferred embodiment of the invention, a guide element is arranged on the lower roller support and has a guide surface extending parallel beyond the free end and at a distance from the bearing element. During assembly of the air spinneret to the lower roller support, the guide element serves as a stop element, which makes it easier for the machine operator to arrange the air spinneret on the bearing element. The air spinneret is placed against the guide surface by the machine operator adjacent to the free end of the bearing element. Once in contact with the guide surface, the air spinneret can then be displaced by a movement parallel to the guide surface in the direction of the end of the bearing element opposite the free end of the bearing element. The spinneret can thus be easily pushed onto the bearing element.The guide surface serves as an assembly aid, which enables particularly simple and quick assembly of the air spinneret on the lower roller support.

[0020] The invention further achieves the object by an air-jet spinning machine for producing a thread or roving from a supplied fiber sliver, which has at least one drafting unit according to the invention or preferably further developed as described above.

[0021] The air-jet spinning machine according to the invention has the advantage that, if necessary, the air-jet spinneret can be removed from the spinning station in a particularly simple and convenient manner. Maintenance and cleaning work can thus be carried out conveniently and quickly, resulting in minimal downtime during maintenance work.

[0022] Embodiments of the invention are explained below with reference to the drawings, wherein like reference numerals are used for like functional elements. In the drawings: Fig. 1 is a schematic representation of a perspective view of a partial area of a drafting system unit with an air spinneret separated from a bearing element; Fig. 2 is a schematic representation of a perspective view of a partial area of the drafting system unit of Fig. 1 with the air spinneret pushed onto the bearing element in a maintenance position; Fig. 3 in schematic representation a perspective view of a portion of the drafting unit of Fig. 1 with the air spinneret arranged in an operating position, Fig. 4 in schematic representation a perspective view of a portion of the drafting unit of Fig. 1, and Fig. 5 in schematic representation a perspective view of a partial area of a drafting unit with the air spinneret arranged in an operating position according to a further embodiment.

[0023] One in Figure 1 A schematic perspective view of a drafting unit 1 shows the connection area of an air spinneret 2 in the area of an output bottom roller 3 on a bottom roller support 4 according to an embodiment. Figure 1 the air spinneret is separated from the lower roller support 4.

[0024] The air spinneret 2 has a support 13 with a bearing element holder 14 extending through the support 13 for arrangement on the lower roller support 4. To arrange the air spinneret 2 on the lower roller support 4, the bearing element holder 14 is pushed onto a bearing element 5 designed as a bearing pin in the direction of a bearing element carrier 10 carrying the bearing pin into the Figure 2 shown pushed onto the bearing pin 5.

[0025] In the Figure 2In the maintenance position of the air spinneret 2 shown, which according to one embodiment constitutes a second position, the air spinneret 2 is pushed completely onto the bearing pin via a free end 6 of the bearing pin, with an end face of the support 13 facing the bearing element support 10 resting against a circumferential stop element 7 of the bearing pin. A snap ring 9 is used to secure the pushed-on position of the air spinneret 2 on the bearing pin; this snap ring is inserted in the region of the free end 6 of the bearing pin into a groove 8 surrounding the bearing pin.

[0026] To simplify the arrangement of the air spinneret 2 on the lower roller support 4, a guide element 11 is arranged on the lower roller support 4, the guide surface 12 of which extends parallel to the bearing pin beyond its free end 6. To assemble the air spinneret 2, it is Figure 1shown position with the carrier 13 brought into contact with the guide surface 12 and pushed onto the latter over the free end 6 of the bearing pin until the carrier 13 rests with its end face facing the bearing element carrier 10 against the stop element 7 of the bearing pin (cf. Figure 4 ).

[0027] From the Figure 2 In the maintenance position shown, the air spinneret 2 can be rotated around the bearing pin or around the pivot axis formed by the bearing pin up to the position shown in Figure 3 shown operating position and back again, wherein the air spinneret 2 in the operating position is arranged downstream in the fiber sliver transport direction of a clamping line formed by the output lower roller 3 and the output upper roller not shown here for receiving the fed fiber sliver.

[0028] Figure 5shows a further embodiment, wherein, in contrast to the previous embodiment, the sliding direction of the air spinneret 2 is reversed. The stop element 7 of the bearing pin is arranged along the sliding direction at the right end of the bearing pin, whereby the air spinneret 2 can be pushed on from the left over the left-hand free end 6 of the bearing pin. The guide element 11 is arranged at a corresponding position on the lower roller support 4. In the pushed-on state of the air spinneret 2, the support 13 of the air spinneret 2 has, on the side facing the free end 6 of the bearing pin, an end section 15 pushed onto the bearing pin, which has a bore for receiving a pressure piece 16, in particular a spring-loaded pressure piece.According to this embodiment, the pressure piece 16 is screwed into the bore 15 and engages with its tip in a recess (not shown) on the bearing pin that is congruent with the tip of the pressure piece 16. According to one embodiment, the recess is designed as a circumferential groove 8 on the bearing pin. This allows the air spinneret 2 to be securely fixed on the bearing pin. To disassemble the air spinneret 2, the pressure piece 16 must be loosened in a defined unscrewing direction, whereby the air spinneret 2 becomes freely movable along the sliding direction. The use of such a pressure piece 16, in particular a spring-loaded pressure piece, simplifies the assembly and disassembly of the air spinneret 2 on or from the bearing pin. List of reference symbols

[0029] 1Drafting unit 2Air spinneret 3Output bottom roller 4Bottom roller support 5Bearing element 6Free end 7Stop element 8Groove 9Snap ring 10Bearing element support 11Guide element 12Guide surface 13Support 14Bearing element holder 15End section of the support 16Pressure piece

Claims

1. A drafting system unit (1) for a spinning unit of an air jet spinning machine for producing a thread or roving from a supplied fiber strip, with - at least one front roller pair consisting of a front top roller on a load carrier and a driven front bottom roller (3) on a bottom roller carrier (4) and forming a clamping line, and - a bearing element (5) arranged on the bottom roller carrier (4) for movably bearing an air jet spinning nozzle (2), characterized in that the bottom roller carrier (4) comprises a bearing element (5) having at least one free end (6), via which the air jet spinning nozzle (2) can be received, wherein the bearing element (5) forms a pivot axis for pivoting the air jet spinning nozzle (2) between an operating position and at least one second position spaced apart therefrom, wherein the bearing element (5) is connected to a portion spaced apart from the free end (6) on the bottom roller carrier (4).

2. The drafting system unit (1) according to claim 1, characterized in that the second position is a maintenance position or a position different therefrom.

3. The drafting system unit (1) according to claim 1 or 2, characterized in that the bearing element (5) has a stop element (7) in a portion opposite the free end (6).

4. The drafting system unit (1) according to one or more of the preceding claims, characterized in that the bearing element (5) is designed in the region of the free end (6) for receiving a position securing element.

5. The drafting system unit (1) according to one or more of the preceding claims, characterized in that the bearing element (5) is arranged on a pivot axis carrier (10) of the bottom roller carrier (4).

6. The drafting system unit (1) according to claim 5, characterized in that the bearing element (5) is formed by a bearing pin held stationary by the pivot axis carrier (10), in particular a bearing pin pressed or screwed into the pivot axis carrier (10).

7. The drafting system unit (1) according to one or more of the preceding claims, characterized in that the bearing element (5) is arranged in such a manner that the air jet spinning nozzle (2) can be pivoted along a direction of movement extending transversely to the axis of rotation of the front roller (3), in particular extending orthogonally, between the operating position and at least the second position.

8. The drafting system unit (1) according to one or more of the preceding claims, characterized by a guide element (11) arranged on the bottom roller carrier (4) having a guide surface (12) extending parallel beyond the free end (6) and at a distance from the bearing element (5).

9. An air jet spinning machine (1) for producing a thread or roving from a supplied fiber strip, characterized by a spinning unit having a drafting system unit (1) according to one or more of claims 1 through 8.

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