US20140237985A1

US20140237985A1 - Spinning Unit for the Production of a Yarn

Info

Publication number: US20140237985A1
Application number: US14/191,988
Authority: US
Inventors: Gernot Schäffler
Original assignee: Maschinenfabrik Rieter AG
Current assignee: Maschinenfabrik Rieter AG
Priority date: 2013-02-28
Filing date: 2014-02-27
Publication date: 2014-08-28
Also published as: CN104018255B; DE102013101988A1; JP6254453B2; CN104018255A; EP2772572B1; DE102013101988A9; JP2014169522A; EP2772572A9; IN2014DE00498A; EP2772572A1

Abstract

The invention relates to a spinning unit of the air-jet spinning machine, which serves the purpose of producing a yarn (2) from a fiber composite (3), whereas the spinning unit (1) possesses a spinning nozzle (4) with a vortex chamber (6) featuring an inlet opening (5) for the fiber composite (3), whereas the spinning unit (1) features air jets (21) directed into the vortex chamber (6), which flow into the vortex chamber (6) in the area of a wall (7) surrounding the vortex chamber (6) and through which air jets, during operation of the spinning unit (1), compressed air can be introduced into the vortex chamber (6) in a given direction of rotation, in order to confer upon the fiber composite (3) a rotation in the specified direction of rotation, and whereas the air jets (21) are connected to a source of compressed air (9) with the assistance of at least one fluid connection (8). In accordance with the invention, it is provided that the spinning unit (1) includes at least one replaceable throttle element (10), with the assistance of which the volume flow of the compressed air, which flows from the source of compressed air (9) into the vortex chamber (6) during the operation of the spinning unit (1), is limited, whereas the throttle element (10) is placed in the flow path of the compressed air between the source of compressed air (9) and the air jets (21).

Description

This invention relates to a spinning unit of an air-jet spinning machine, which serves the purpose of producing a yarn from a fiber composite, whereas the spinning unit possesses a spinning nozzle with a vortex chamber featuring an inlet opening for the fiber composite, whereas the spinning unit features air jets directed into the vortex chamber, which flow into the vortex chamber in the area of a wall surrounding the vortex chamber and through which air jets compressed air can be introduced into the vortex chamber in a given direction of rotation, in order to confer upon the fiber composite a rotation in the specified direction of rotation, and whereas the air jets are connected to a source of compressed air with the assistance of at least one fluid connection.
Spinning units conforming to this type are known in the state of the art, whereas the term “yarn” is generally understood to mean a fiber composite, for which at least one part of the fibers is wound around an inner core. As such, this includes, for example, a yarn in the conventional sense, which may be processed into a fabric, for instance with the assistance of a weaving machine. Likewise, the invention relates to air-jet spinning machines, with the assistance of which so-called “roving” (another name: coarse roving) can be produced. This type of yarn is distinguished by the fact that, despite a certain strength, which is sufficient for carrying the yarn to a subsequent textile machine, it is still capable of being drafted. Thus, with the assistance of a drafting device, for example the drafting system of a textile machine processing the roving, for example a ring spinning machine, the roving can be drafted, before it is finally spun.
However, regardless of the strength of the yarn, it is always desirable that the air jets flowing into the vortex chamber are applied with a defined atmospheric pressure, since this has direct effects on the air flow within the vortex chamber and thus on the individual yarn parameter (strength, grip, etc.) and/or the yarn quality.
If the spinning pressure (=atmospheric pressure in the area of the air jets) is modified for the production of a new type of yarn, changing the atmospheric pressure of the source of compressed air supplying the spinning unit(s) with compressed air is known in the state of the art. Purely as a precautionary measure, it must be noted at this point that, with the framework of the invention, the term “source of compressed air” is understood to be that section of the air-jet spinning machine through which the individual components/elements of the air-jet spinning machine requiring compressed air (such as valves, compressed air cylinders, air jets of the spinning unit(s)) are supplied with compressed air. This may be, for example, a pipe arrangement, which is connected to the respective components/elements on the one hand, and to a compressed air generator and/or the compressed air system of a spinning mill.
However, for such an approach, it is disadvantageous that a corresponding reduction in pressure in the area of the source of compressed air has effects not only on the spinning pressure, but also on the other components of the air-jet spinning machine requiring compressed air. However, since such components are usually designed at a defined target pressure, malfunctions in such cases cannot be ruled out.
The task of this invention is to address this disadvantage and to propose a spinning machine with which, when needed, spinning pressure may be reduced as much as possible without negative effects on components located outside the spinning nozzle.
The task is solved by a spinning unit with the features of claim 1.
In accordance with the invention, the spinning unit is characterized by the fact that it includes at least one replaceable throttle element. The term “throttle element” is understood to mean a component of the spinning unit that is placed in the flow path of the compressed air between the source of compressed air (such as in the form of a compressed air pipe) and the air jets specified above. Thereby, the throttle element serves as a limit on the volume flow of compressed aft that flows from the source of compressed air during the operation of the spinning unit, along its flow path into the vortex chamber. In other words, there is optional use of a throttle element that, at a defined atmospheric pressure of the source of compressed air, enables a certain air volume flow in the area of the air jets. This specific air volume flow in turn results in a certain atmospheric pressure in the area after the throttle element (seen in the direction of flow of the compressed air), such that, at a given atmospheric pressure from the source of compressed air, depending on the selection of the corresponding throttle element, the spinning pressure may be adjusted to a defined amount, which in turn is smaller than (or, at a maximum, equal to) the atmospheric pressure from the source of compressed air.
While the atmospheric pressure within the source of compressed air may always remain constant (this has positive effects on the manner of operation of the components requiring atmospheric pressure, which are placed outside the spinning nozzle), the spinning pressure is, depending on the selection of throttle element, adjustable to a desired value (preferably to a value between 3 and 6 bar).
In particular, it is advantageous if the throttle element is part of the fluid connection. Thus, it is conceivable to integrate the throttle element directly into the fluid connection, which runs between the spinning nozzle and the source of compressed air or a corresponding connection area of the same. Thereby, the throttle element may in turn be designed as a component detachably connected to the fluid connection, which is found in the flow path dictated by the fluid connection or forms this together with the fluid connection. Thus, while the throttle element can be placed as a separate component between two fluid connections and can be replaced accordingly, it is also conceivable that the throttle element itself includes one or more fluid connections. The throttle element could include, for example, two compressed air tubes and one throttle section connecting the two compressed air tubes, whereas this in turn could be connected to the compressed air tubes in a fixed or detachable manner. In this case, it would ultimately be possible to replace not only the throttle section, but the entire throttle element, which in this case would include the throttle section and one or more fluid connections, in order to limit the volume flow of the compressed air at the corresponding spinning unit to a given value.
It is advantageous if the throttle element features a minimum inner cross-sectional area that is smaller than the minimum inner cross-sectional area of the fluid connection. This eventually causes the compressed air volume flow to be throttled in respect of one design, for which no throttle element would be available. Therefore, the spinning pressure can be determined through the selection of the minimal inner cross-sectional area and/or of the corresponding throttle element.
It is also advantageous if the fluid connection is designed in tubular form. The tube preferably runs from a connection section of the spinning nozzle to a connection section of the source of compressed air spaced from this, whereas additional components (such as in the form of valves) may naturally be present between the connection section last mentioned and the source of compressed air, with which the individual spinning units may be moved from an idle mode (in which no compressed air streams through the air jets) into an operational state (in which the production of yarn is carried out).
It is also advantageous if the fluid connection features at least two separate tube sections, and the throttle element is placed between the respective tube sections. Thus, it can be advantageous if the fluid connection features a first tube section, which connects the spinning nozzle to the throttle element, and a second tube section, which connects the throttle element to the source of compressed air. The throttle element is preferably connected to the two tube sections in a detachable manner, and, depending on the yarn to be produced, may be replaced quickly and preferably without tools.
It is likewise advantageous if the throttle element is formed in one piece. For example, the use of a corresponding injection-molding component, which must be plugged solely between the corresponding connection sections of the fluid connection, or correspondingly placed in another manner, is conceivable.
It is also expressly advantageous if the throttle element is made of plastic. Particularly since, for each spinning unit, a multiple number of throttle elements must be deposited with different throttle characteristics, in order to be able to adjust all spinning units together for a new type of yarn, it is advantageous if the costs of the throttle elements that are used are kept within certain limits.
It is also advantageous if the throttle element is connected to the fluid connection, the spinning unit and/or the source of compressed air with the assistance of one or more plug connection(s) and/or screw connection(s). Such connections are quick, and are usually able to be made or detached without tools, such that, when necessary, the rapid replacement of the respective throttle elements may be carried out.
It is also advantageous if the throttle element features at least one connection section, with which it is connected to the fluid connection, the spinning unit or the source of compressed air in a positive-locking or frictional-locking manner. In the ideal case, the connection is carried out without additional fastening elements, such that the integration of the throttle elements or its connection sections is able to be realized simply and cost-effectively. The respective connection may be carried out, for example, with the assistance of corresponding latches or clip connections.
It is advantageous if the connection section features an uneven outer contour, through which it is connected to the fluid connection, the spinning unit and/or the source of compressed air. For example, the connection section(s) could feature ring-shaped elevations and constrictions, such that a tube section of the fluid connection sliding on the respective connection section is able to be securely connected to the throttle element.
It also advantageous if the throttle element is connected to the fluid connection, the spinning unit and/or the source of compressed air by one or more quick coupler(s). Corresponding connection elements are generally known in the state of the art, and enable a rapid production or release, as the case may be, of the connection of the specified components, without tools. Thereby, it is typical that a spring or locking mechanism is provided, which, after the connection of the individual components to the quick coupler, prevents the respective components from being inadvertently disconnected. If a desired separation is carried out, for example, because the relevant throttle element is to be replaced with a throttle element with a different minimum inner cross-section, only the specified spring or locking mechanism must be operated to bring about a release of the corresponding locking/fixing.
It is also advantageous if the spinning unit possesses multiple throttle elements connected in series or parallel, which are placed in the flow path of the compressed air between the source of compressed air and the air jets. In this manner, it is possible to realize a variety of spinning pressures with a small number of base throttle elements. For example, a throttle, which, at an atmospheric pressure from the source of compressed air of 6 bar, would bring about a spinning pressure of 3 bar, could be connected in parallel to a throttle, which, upon an equivalent atmospheric pressure from the source of compressed air, would bring about a spinning pressure of 5 bar. In such a case, a spinning pressure of approximately 4 bar would ultimately be obtained.
Finally, it can be advantageous that the throttle element(s) is/are marked by color or by corresponding shape. The marking could correspond, for example, to the volume flow of the compressed air, which passes by the throttle element at a certain atmospheric pressure applied to the respective throttle element. In addition to the marking of the throttle element, it could be equally advantageous to mark (by color) the tube sections connected to the throttle element.

Additional advantages of the invention are described in the following embodiments. The following is shown:

FIG. 1 a partially cut side view of a spinning unit in accordance with the invention,

FIG. 2 a cut-out of the section essential to the invention of a spinning unit in accordance with the invention,

FIG. 3 an alternative design of the section shown in FIG. 2, and

FIG. 4 a throttle element in accordance with the invention.

In FIG. 1, a partially cut side view of the spinning unit 1 of the air-jet spinning machine is shown, as it is already known in the state of the art. The spinning unit 1 comprises a spinning nozzle 4 with an inlet opening 5, through which the fiber composite 3 to be spun (mostly in the form of a drafted fiber composite) arrives in the so-called “vortex chamber” 6 of the spinning unit 1, in which the actual spinning process in turn takes place. The drafting is usually performed in a drafting system upstream to the spinning unit 1 (not shown in the figures), from which the drafted fiber composite 3 is drawn, for example with the assistance of a pair of draw-off rollers. Finally, the fiber composite 3 is preferably captured by a pair of delivery rollers, whereas its delivery rollers 19 are to be placed as much as possible in the immediate vicinity of the inlet opening 5, in order to ensure that the fiber composite 3 may be delivered, reliably and evenly, from the drafting system to the spinning nozzle 4.
After the fiber composite 3 has passed the inlet opening 5 of the spinning nozzle 4, it arrives in the effective area of several air jets 21, as a rule flowing through a corresponding wall 7 tangentially into the vortex chamber 6, which may be connected with each other, for example, with the assistance of a ring channel 17, shown in FIG. 1. If, during the spinning operation, the ring channel 17 and the air jets 21 branching off from it are subject to an excess pressure, this gives rise to a vortex air flow, which flows around the upper area of a yarn formation element 18 protruding into the vortex chamber 6. If the outwardly protruding fiber ends of the fiber composite 3 arriving in the vortex chamber 6 are captured by this air flow, this gives rise to the desired rotation of the fiber material in the area of the yarn formation element 18 and, as a result, the desired yarn 2, which ultimately may be drawn through a draw-off channel 22 from the vortex chamber 6.
In general, it should be clarified at this point that the produced yarn 2 generally concerns an arbitrary fiber composite 3, which is characterized by the fact that an external part of the fibers (so-called “wrapped fibers”) is wrapped around an inner, preferably untwisted part of the fibers, in order to impart a certain strength on the yarn 2. In addition to conventional air-jet spinning machines, with the assistance of which a yarn 2 in the conventional sense (which can be processed into a fabric with the assistance of, for example, a weaving machine) can be produced, the invention also includes an air-jet spinning machine, with the assistance of which so-called “roving” can be produced. Roving concerns a yarn 2 with a relatively low share of wrapped fibers, or a yarn 2, for which the wrapped fibers are looped relatively loosely around the inner core, such that the yarn 2 remains capable of being drafted. This is crucial if the produced yarn 2 should be or must be drafted on a subsequent textile machine (for example, a ring spinning machine), once again with the assistance of a drafting system, in order to further process it accordingly.
Regardless of the type of yarn 2 to be produced (conventional yarn or roving), it is common with all air-jet spinning machines that the spinning unit(s) 1 is/are connected to a source of compressed air 9 by a fluid connection 8, through which the air jets 21 may ultimately be supplied with the necessary compressed air (whereas the spinning nozzle 4 itself may feature a preferably internal air line 20, with the assistance of which in turn there is a connection of the specified ring channel 17 and fluid connection 8 connecting the spinning nozzle 4 with the source of compressed air 9).
In FIG. 1, as an example, a pipe is shown as the source of compressed air 9, in which a corresponding excess pressure predominates (which, for example, is connected with the assistance of a compressed air generator for the air-jet spinning machine, or to the compressed air supply of a spinning mill). However, as a general rule, within the framework of the invention, the term “source of compressed air” is understood to be the (however developed) area of the air-jet spinning machine that (at least during yarn production) is subject to a certain excess pressure and is connected to the spinning unit 1 through a corresponding fluid connection 8, such that air from the source of compressed air 9 may flow into the spinning nozzle 4.
Naturally, there may also be valves or other control devices between the air jets 21 and the source of compressed air 9, through which the spinning unit 1 is able to be brought from an idle mode (in which no air flows through the air jets 21) into a production mode, in which air streams into the vortex chamber 6, in order to produce the desired yarn 2.
Regardless of the exact form of the source of compressed air 9 and/or the fluid connection 8, it is typical in the state of the art that the source of compressed air 9 is connected not only with the spinning nozzle(s) 4, but also to other compressed air-operated elements, such as valves or compressed air cylinders. The specified elements are usually designed at a standard spinning pressure of, for example, 6 bar, which in turn is made available by the source of compressed air 9.
If the spinning pressure, i.e. the atmospheric pressure in the air jets 21, is changed during the spinning process in order to correspondingly influence certain yarn parameters (strength, grip, etc.), this has mostly negative effects on the manner of operation of the remaining compressed air-operated elements, such as the valves or compressed air cylinders specified above, since, after the central adjustment of the atmospheric pressure made available by the source of compressed air 9, they are subject to pressure deviating from the standard atmospheric pressure.
In other words, in the state of the art, the spinning pressure may be changed only by the central adjustment of the atmospheric pressure made available by the source of compressed air 9, whereas this not infrequently has negative effects on other elements of the air-jet spinning machine.
In order to counter this disadvantage, in accordance with the invention, it is now proposed that the spinning unit 1 is to be equipped with at least one throttle element 10, with the assistance of which the volume flow of the compressed air, which passes by the fluid connection 8 during the operation of the spinning unit 1, is limited. On the basis of this limitation on volume flow, there is a reduction in atmospheric pressure, such that the atmospheric pressure, which is ultimately applied to the air jets 21, is smaller than the atmospheric pressure made available by the source of compressed air 9. Thus, depending on the throttle element 10 used, the spinning pressure may be reduced to a greater or lesser degree in respect of the atmospheric pressure of the source of compressed air 9. This ultimately has the crucial advantage that the atmospheric pressure that is made available by the source of compressed air 9 cannot be maintained, such that the respective acceptors (valves, compressed air cylinders, etc.) of the air-jet spinning machine are always subject to a constant atmospheric pressure. By doing so, failures due to atmospheric pressure that is too low may easily be avoided.
By contrast, through a suitable selection of the throttle element 10, the spinning pressure applied to the air jets 21 may be adjusted to an arbitrary pressure between (theoretically) 0 bar and the (maximum) pressure made available by the source of compressed air 9. As a result, with a constant pressure from the source of compressed air, the production of different yarns 2 is possible, whereas only one corresponding throttle element 10 must be used for this, or the throttle element 10 currently used must be replaced with a throttle element 10 with a modified flow cross-section.
As shown by example in FIGS. 2 to 4, there are now various options for arranging or placing the throttle element 10 in accordance with the invention, which may be formed (for example) as a one-piece plastic element, and is to feature a minimum flow cross-section that is smaller than the minimum flow cross-section of the fluid connection 8, in order to enable the desired reduction of the spinning pressure (if there is a desire for a spinning pressure that is equivalent to the atmospheric pressure made available by the source of compressed air 9, a throttle element 10 may naturally also be used, the minimum flow cross-section of which is larger than to or equal to the minimum flow cross-section of the fluid connection 8).
In any event, the throttle element 10 may be connected directly to the spinning nozzle 4 (FIG. 3) or to the source of compressed air 9, or as shown in FIG. 2, integrated into the fluid connection 8, whereas this may be designed, for example, in tubular form, and preferably features a first tube section 11 and a second tube section 12, which in turn are connected to the throttle element 10. In the most simple case, it is ultimately conceivable to integrate the throttle element 10 directly into the fluid connection 8, such that the spinning pressure could be changed by replacing the entire fluid connection 8.
However, it is preferable that the throttle element 10 is formed as a component detachable from the fluid connection 8, whereas the connection between the fluid connection 8 and the throttle element 10 (or between the throttle element 10 and the source of compressed air 9 or the throttle element 10 and the spinning nozzle 4) preferably should be formed in such a manner that a release of the same is possible without the use of a tool.
For example, it is conceivable that the throttle element 10 (which may be formed, for example, as a hollow body provided with two connection sections 14) is connected to the neighboring sections (fluid connection 8, spinning unit 1 or source of compressed air 9) of the spinning unit 1 by a plug connection 13. FIGS. 2 and 4 show a particularly simple arrangement of such a plug connection 13. Thus, the throttle element 10 may feature connection sections 14, which may be overlapped by the fluid connection 8 designed, for example, in tubular form. For a particularly reliable hold, it would also be worth considering to provide the connection sections 14 with an uneven outer contour 15 shown in FIG. 4, such that the accidental removal of the fluid connection 8 or its individual sections (such as in the form of the first tube section 11 or the second tube section 12) can be nearly ruled out.
In a further design of the invention, it is ultimately also conceivable to connect the throttle element 10 to the fluid connection 8, the spinning unit 1 or the source of compressed air 9 with the assistance of one or more quick couplers 16. Such (usually spring-secured) quick couplers 16 are generally known in the state of the art, and enable a particularly easy, rapid and above all tool-free release of the connection between the throttle element 10 and the components of the spinning unit 1 connected to it.
As a result, this invention thus proposes an air-jet spinning machine comprising a spinning unit 1 or several spinning units 1, for which, depending on the desired yarn characteristics and through the selection of the suitable throttle element 10, a defined spinning pressure is adjustable, whereas the atmospheric pressure made available by the source of compressed air 9 must not be changed.
This invention is not limited to the illustrated and described embodiments. Variations within the framework of the patent claims, such as a combination of features, are also possible, even if they are pictured and described in different embodiments.

LIST OF REFERENCE SIGNS

1 Spinning unit
2 Yarn
3 Fiber composite
4 Spinning nozzle
5 Inlet opening
6 Vortex chamber
7 Wall
8 Fluid connection
9 Source of compressed air
10 Throttle element
11 First tube section
12 Second tube section
13 Plug connection
14 Connection section
15 Outer contour
16 Quick coupler
17 Ring channel
18 Yarn formation element
19 Delivery roller
20 Air line
21 Air jet
22 Draw-off channel

Claims

1. Spinning unit of an air-jet spinning machine, which serves the purpose of producing a yarn (2) from a fiber composite (3), whereas the spinning unit (1) possesses a spinning nozzle (4) with a vortex chamber (6) featuring an inlet opening (5) for the fiber composite (3), whereas the spinning unit (1) features air jets (21) directed into the vortex chamber (6), which air jets flow into the vortex chamber (6) in the area of a wall (7) surrounding the vortex chamber (6) and through which air jets, during operation of the spinning unit (1), compressed air can be introduced into the vortex chamber (6) in a given direction of rotation, in order to confer upon the fiber composite (3) a rotation in the specified direction of rotation, and whereas the air jets (21) are connected to a source of compressed air (9) with the assistance of at least one fluid connection (8), characterized in that the spinning unit (1) includes at least one replaceable throttle element (10), with the assistance of which the volume flow of the compressed air, which flows from the source of compressed air (9) into the vortex chamber (6) during the operation of the spinning unit (1), is limited, whereas the throttle element (10) is placed in the flow path of the compressed air between the source of compressed air (9) and the air jets (21).

2-12. (canceled)