EP3610058B1 - Feeding device - Google Patents

Description

The present invention relates to a feed device for feeding fiber flocks into a spinning preparation machine with a feed roller, a feed trough and an open electrical circuit with a voltage source, the circuit being closable by a metal part contaminating the fiber flocks.

From the GB 465,899 a spinning preparation machine is known which has means for detecting metal parts in the fiber material. These means comprise a pair of rollers through which the fiber material runs. The rollers are arranged at a distance from one another. Furthermore, the rollers are arranged in an electrical circuit, the circuit being closed when a metallic foreign body closes the gap between the two rollers. When the circuit has been completed, the fiber material is stopped or moved backwards.

The disadvantage of this solution is that a pair of rollers is required which, on the one hand, impairs the fiber flow and, on the other hand, has to be cleaned and serviced regularly.

Further reveals the WO 90/12131 A1 a feed device for feeding fiber flocks into a spinning preparation machine with a feed roller and a feed trough. A feed roller and the feed trough are electrically insulated from one another and form a metal detection device. The disadvantage of this solution is that non-metallic foreign bodies cannot be recognized.

The object of the present invention is therefore to create a feed device which recognizes metal parts and non-metallic foreign bodies even without the need for an extra pair of rollers.

The object is achieved by a feed device with the features of the independent claim.

A feed device is proposed for feeding fiber flocks into a spinning preparation machine. The spinning preparation machine can be a card, card or cleaner. The feed device has a feed roller, a feed trough and an open electrical circuit with a voltage source. The circuit is through one of the fiber flocks unclean metal part can be closed. Conversely, a closed circuit indicates a metal part contaminating the fiber flakes.

According to the invention, the open ends of the circuit are formed by the feed roller and the feed trough. Two elements of the feed device that are already present are used to detect metal parts. Further mechanical parts that impair the fiber flow and have to be cleaned and serviced are not required.

It is advantageous if the feed trough is electrically insulated from the feed roller. An open circuit can then be formed in which the feed trough and the feed roller are the open ends. The bearing of the feed roller is the insulator. So the isolation can be accomplished with very little effort. The bearing is preferably provided with an electrically insulating coating. The entire bearing of the feed roller and / or a bearing ring of the bearing are particularly preferably made of an electrically insulating plastic. Depending on the size of the feed roller and the mechanical requirements, one of the two variants may prove to be the more advantageous.

As an alternative to the above version, the bearing housing is made of plastic. The component surrounding the bearing rings, which is provided with the fastening devices for resting on the machine, is used as the bearing housing. Furthermore, the bearing bodies, which in the case of a ball bearing are formed, for example, from individual balls held in a bearing cage, can also be provided made of ceramic. Ceramic balls have the necessary running properties with simultaneous electrical insulation. Another alternative of electrical insulation can be achieved by installing appropriate pads between the bearing of the feed roller and the machine or the bearing and the feed roller itself, for example by coating or selecting the appropriate material for the feed roller shaft at the point where the feed roller is held in the bearing .

According to the invention, the feeding trough is assigned an elastic lip. The elastic lip forms a gap between itself and the feed roller. Furthermore, the feed trough has a contact surface and means are provided for detecting contact between the elastic lip and the contact surface. If the elastic lip is deformed by a foreign body, then it comes into contact with the contact surface, provided the foreign body and thus the elastic deformation are large enough. The contact and thus also the foreign body are recognized by the means for recognizing a contact. Through the contact of the elastic lip with the contact surface, non-metallic foreign bodies are also recognized.

Alternatively, the means for detecting a contact can have a piezoelectric element. Piezoelectric elements are inexpensive, reliable and largely maintenance-free. The piezoelectric element can be attached to the elastic lip and / or to the contact surface. When there is contact between the elastic lip and the contact surface, pressure is then exerted on the piezoelectric element, which in turn results in an electrical voltage that is detected by a sensor system.

It is also advantageous if the means for detecting a contact include electrical insulation between the elastic lip and the contact surface. A voltage is applied between the elastic lip and the contact surface and the contact between the elastic lip and the contact surface is detected by closing an electrical circuit. In this way, a contact between the elastic lip and the contact surface can be identified easily and inexpensively, with the electronics required for this in particular being inexpensive and robust.

Advantageously, the electrical potential of the feed trough is equal to the electrical potential of the contact surface and the electrical potential of the feed roller is equal to the electrical potential of the elastic lip, but different from the electrical potential of the feed trough. Thus, with one voltage source, both a metal part between the feed roller and the feed trough and also a metal part caused by a foreign body caused contact between the elastic lip and the contact surface can be detected. The voltage generated by the voltage source is preferably between 1.5 V and 32 V, particularly preferably between 12 V and 28 V. On the one hand, these voltages are easy to generate and, on the other hand, they do not require any extremely sensitive detectors. Furthermore, the voltages are small enough not to pose a risk to the health of the operating personnel, should there be contact with one or both of the electrodes.

It is also advantageous if the electrical potential of the feed trough is equal to the electrical potential of the contact surface and the feed trough, the feed roller and the elastic lip each have a different electrical potential. Thus, although three different electrical potentials are necessary, in contrast to the above, contact between the elastic lip and the feed roller caused by a metal part can also be detected. Such a metal part can therefore be detected as soon as it has not yet deformed the elastic lip to such an extent that it comes into contact with the contact surface. The voltages, i.e. the potential differences, are again in the ranges mentioned above.

The elastic lip and the contact surface form an opening to a cavity which, among other things, enables the elastic lip to move. So that this cavity is not contaminated, a seal is advantageously arranged between the elastic lip and the contact surface. This seal is deformable to such an extent that it can be pressed over when the elastic lip is deformed and thus does not hinder the electrical contact between the elastic contact surface or the pressure on the piezoelectric element.

It is advantageous if a spacer bar is arranged between a base body of the feed trough and the elastic lip. This makes it possible to achieve a distance between the base body and the elastic lip that is optimal for clamping the fiber material. So that this distance can be adapted for different fiber lengths, the spacer bar is preferably exchangeable and / or adjustable. With especially long fiber lengths, above about 28 mm, the spacer bar can then be completely dispensed with.

It is also advantageous if the elastic lip is made of steel, in particular of chrome steel, since these materials have good elasticity with a good spring strength. Chrome steel is also corrosion-resistant. A wall thickness of the elastic lip at its front end is preferably between 1.0 mm and 4.0 mm, particularly preferably between 1.5 mm and 2.0 mm, since this provides the necessary spring strength.

The contact surface is advantageously assigned to a support strip. The support strip is arranged at such a distance from the elastic lip that the distance can be closed by elastic deformation of the elastic lip. If there were no support bar, a very large foreign body could deform the elastic lip so much that it leaves the elastic area and then does not return to its previous shape. The support strip prevents this and thus enables the elastic lip to last longer. A particularly suitable material for the support strip is aluminum, since it has great dimensional stability while being light.

It is advantageous if the feeding trough is divided into at least two segments along a working width of the feeding trough, an elastic lip being assigned to each segment. This simplifies the setting of the gap created by the elastic lip, since a constant gap width no longer has to be set over the entire working width.

A piezoelectric element is advantageously assigned to each segment or the elastic lips assigned to the individual segments are electrically isolated from one another and assigned to separate circuits. It is therefore possible to identify a foreign body separately for each segment. If this is indicated to the operating personnel, the search for the foreign body is simplified, the foreign body can consequently be removed more quickly and production can be resumed more quickly. It is also advantageous if the feed device comprises an acoustic and / or visual alarm that is triggered when there is contact between the elastic lip and the contact surface and / or the circuit between the feed roller and the feed trough and / or the elastic lip is closed. The alarm is triggered if a metal part contaminating the fiber flakes and / or another foreign body is detected. This draws the operator's attention to the metal part or the foreign body. The operating personnel can then stop production and / or remove the metal part or the foreign body.

Finally, it is advantageous if the feed device comprises a control device which, when there is contact between the elastic lip and the contact surface and / or a closed circuit between the feed roller and the feed trough and / or the elastic lip, interrupts the feed of the fiber flocks and the feed roller persists. The shutdown is advantageously controlled directly via the feed roller drive or its frequency converter. This enables the feed roller to be switched off immediately. With modern feed devices, it is possible for the surface of the feed roller to move only 10 mm further from the time a metal part or foreign body is detected until it comes to a standstill. In this way, damage to the feed roller and the feed trough can largely be avoided. In front of the control unit of the feed roller drive, the signal is forwarded to a central controller, which switches off the feed.

In order to achieve a higher level of operational reliability, it is advantageous if the shutdown of the feed or the feed roller in the event of contact between the elastic lip and the contact surface and / or a closed circuit between the feed roller and the feed trough and / or the elastic lip is dependent on lifting the food tray is activated. This means that the shutdown is not active when there is no supply, which means that incorrect switching can be avoided, for example due to vibrations when the machine is empty.

Preferably, after the feed roller has come to a standstill, the control device rotates it back by a predefined or predefinable angle. This angle is or is set in such a way that the metal part or the foreign body reaches an area from which it can be easily removed by the operating personnel.

The feed device is designed according to the preceding description, it being possible for the features mentioned to be present individually or in any combination.

Figur 1

eine schematische Seitenansicht einer Karde,

Figur 2

eine schematische Seitenansicht einer Speisevorrichtung,

Figur 3

einen schematischen Querschnitt durch ein Lager einer Speisewalze,

Figur 4

einen schematischen Querschnitt durch ein weiteres Lager einer Speisewalze,

Figur 5

eine schematische Seitenansicht einer weiteren Speisevorrichtung,

Figur 6

eine schematische Seitenansicht einer weiteren Speisevorrichtung,

Figur 7

eine schematische Seitenansicht einer weiteren Speisevorrichtung und

Figur 8

eine schematische Frontansicht einer Speisemulde.

Further advantages of the invention are described in the following exemplary embodiments. Show it:

Figure 1

a schematic side view of a card,

Figure 2

a schematic side view of a feed device,

Figure 3

a schematic cross section through a bearing of a feed roller,

Figure 4

a schematic cross section through another bearing of a feed roller,

Figure 5

a schematic side view of a further feed device,

Figure 6

a schematic side view of a further feed device,

Figure 7

a schematic side view of a further feed device and

Figure 8

a schematic front view of a food tray.

Figure 1 shows a schematic side view of a card 1. The fibers in the card 1 are transported from left to right. A fiber mat 2 first runs over a feed plate 3 and then reaches a feed device 4. The feed device 4 has a feed trough 5 which interacts with a feed roller 6. The fiber mat 2 clamped between the feed trough 5 and the feed roller 6 is then fed to a lickerin roller 7.

From the licker-in roller 7, the fiber fleece goes on to a reel 8 and is processed further between the reel 8 and a cover 9, shown here very schematically. The fiber fleece is then removed from a doffer roller 10 and passed on to a compacting unit 11, where it is compacted to form a card sliver 12.

Figure 2 FIG. 4 shows a schematic side view of a feed device 4 according to the invention. The feed device 4 can be part of the FIG Figure 1 shown card 1, but it can also be part of a card or a cleaner. The feed device 4 has a feed trough 5 and a feed roller 6. A part of the lickerin roller 7 is also shown.

The feed trough 5 and the feed roller 6 are arranged as open ends in an open circuit. The feed roller 6 can be electrically connected via its axis, for example. The circuit also includes a voltage source 13 and a current measuring device 14. If the gap between the feed trough 5 and the feed roller 6 is closed by a metal part contaminating the fiber flocks, the circuit is also closed. A current then flows which is detected by the current measuring device 14. A current flow detected by the current measuring device 14 thus indicates a metal part between the feed trough 5 and the feed roller 6.

In order to display the current flow in the circuit and thus the detection of the metal part, the current measuring device 14 is connected to an acoustic and / or optical alarm 15, which indicates the metal part to the operating personnel.

The current measuring device 14 is also advantageously connected to a control device 16 which, when a metal part is detected, stops the feed roller 6 so that the metal part does not advance further and does not cause major damage. It is particularly advantageous if the control device 16, after it has been stopped, still rotates the feed roller 6 backwards so far that the metal part comes out from under the feed trough 5 and can be easily removed by the operating personnel.

In order to keep the circuit open, the feed trough 5 and the feed roller 6 must be electrically isolated from one another. This insulation can be achieved via an electrically insulating bearing 17 of the feed roller 6, which is shown in FIG Figure 3 is shown in cross section. The electrical insulation of the bearing 17 can be achieved by a corresponding coating of the bearing surfaces. In the embodiment of Figure 3 the entire bearing 17 of the feed roller 6 consists of an electrically insulating plastic. The axis 18 of the feed roller 6 is consequently electrically isolated from the bearing 17 and the other parts of the feed device 4.

In the alternative embodiment of the Figure 4 there is only one bearing ring 19 of the bearing 17 made of an electrically insulating plastic, while the main body 20 of the bearing 17 can also be electrically conductive. The axis 18 of the feed roller 6 is also in this case electrically isolated from the bearing 17 and the other parts of the feed device 4.

In the following description of alternative exemplary embodiments, the same reference symbols are used for features that are identical and / or at least comparable in their design and / or mode of operation compared to other exemplary embodiments. Unless these are explained again in detail, their design and / or mode of action corresponds to the design and mode of action of the features already described above.

The one in the Figure 5 The embodiment shown is only shown a part of the feed roller 6 so that the details of the feed trough 5 can be made more visible. The electrical connection to the feed roller 6 is also shown only very schematically, but it can take place via the axis of the feed roller 6 as above.

The feed tray 5 in the exemplary embodiment of FIG Figure 5 has a base body 21 which is partially protected from wear by a protective plate 22. Furthermore, a spacer strip 23 is arranged on the base body 21 in order to enable an optimal distance between the base body 21 and an elastic lip 24. The spacer bar 23 is designed to be exchangeable so that it can be adapted to the respective fiber length. In the case of very long fibers, the spacer bar 23 can even be omitted entirely.

The elastic lip 24 is arranged so that fibers can be clamped between it and the feed roller 6. A support strip 25 is also arranged on the side of the elastic lip 24 facing away from the feed roller 6. The elastic lip 24 can be elastically deformed at least until it touches the support strip 25. The support strip 25 prevents further deformation of the elastic lip 24, for example due to a hard foreign body in the fiber material. The elastic lip 24 is therefore in particular not deformed in an area in which permanent deformation occurs. A return of the elastic lip 24 to its original shape and position is always guaranteed.

In order to protect the space 26 between the elastic lip 24 and the support strip 25 from soiling, in particular from flying fibers, an easily deformable seal 27 is arranged between the elastic lip 24 and the support strip 25.

In order to detect a hard foreign body which presses the elastic lip 24 against a contact surface 28 of the support strip 25, the elastic lip 24 and the support strip 25 are also arranged in the circuit. For this purpose, an electrical insulation 29 first isolates the elastic lip 24 from the support strip 25.

The electrical circuit in this exemplary embodiment is constructed in such a way that the voltage source 13 supplies a positive (+ U) and a negative (-U) voltage in addition to earth (0 V). The amounts of the positive and negative voltage do not have to be the same and other obvious designs of the voltage source are also possible. The positive voltage is applied to the elastic lip 24, the negative voltage is applied to the feed roller 6 and the support strip 25 and the base body 21 or the protective plate 22 of the feed trough 5 are connected to earth.

A metal part contaminating the fiber flocks, which brings the feed trough 5 into contact with the feed roller 6, closes a circuit, as described above, and the current flow is detected by the current measuring device 14. If, on the other hand, the elastic lip 24 is deformed, for example by a hard foreign body, to such an extent that it touches the contact surface 28 of the support strip 25, then another circuit is closed and current flows, which another current measuring device 30 measures. A smaller metal part, which has not yet been able to make contact between the feed roller 6 and the base body 21 of the feed trough 5, but makes contact between the feed roller 6 and the elastic lip 24, can also be detected. A circuit is closed, which results in a current flow through the current measuring device 14 and the further current measuring device 30. A current flow through the two current measuring devices 14 and 30 consequently indicates a metal part between the feed roller 6 and the elastic lip 24.

The alarm 15 and the control device 16 are not shown in this figure for the sake of clarity. Preferably, however, the measured values of both current measuring devices 14 and 30 are used by the control device 16 to trigger an alarm 15 and to stop and / or retract the feed roller 6. For example, the alarm can use different tones, colors or other representations to indicate in which area a metal part and / or foreign body was detected. The angle by which the feed roller is moved back after a stop can also be selected as a function of the area in which the metal part or the foreign body was detected. For example, for a metal part that has contact between the feed roller 6 and the The base body 21 of the feed trough 5 has triggered, be smaller than the angle for a foreign body, which first brought the elastic lip 24 into contact with the contact surface 28 of the support strip 25.

In an embodiment not shown here, the feed roller 6 and the elastic lip 24 have the same electrical potential. A simpler voltage source 13 can therefore be used. A measurement of an electrical contact between the feed roller 6 and the elastic lip 24, triggered by a smaller metal part, is then no longer possible.

The in Figure 6 The embodiment shown, the contact between the elastic lip 24 and the contact surface 28 is detected by a piezoelectric element 31. In this case, the piezoelectric element 31 is arranged on the contact surface 28 of the support strip 25, but it can also be arranged on the elastic lip 24. When there is contact between the elastic lip 24 and the contact surface 28, pressure is exerted on the piezoelectric element 31, which leads to an electrical voltage between two electrodes of the piezoelectric element 31. This electrical voltage is measured and thus the contact is detected.

The circuit for detecting a metal part between the feed roller 6 and the feed trough 5 is analogous to that in FIG Figure 2 shown executed. The alarm 15, not shown here, and the control device 16 are advantageously also connected to the measuring device of the piezoelectric element 31 so that a differentiated alarm can be triggered and / or the feed roller can be optimally stopped and / or retracted.

In this exemplary embodiment, the feed trough 5 is shown without a spacer bar, which is optimal for particularly long fiber lengths.

At the in Figure 7 The feed trough 5 shown, the spacer bar 23 is designed as an adjustable rod 32. It can therefore be adjusted to different fiber lengths without complex modifications.

Furthermore, in the exemplary embodiment Figure 7 no support bar provided. The contact surface 28 is arranged on an electrically insulating holder 33. As a result, no separate insulation of the elastic lip 24 is required either. As a possible electrical circuit, the base body 21 or the protective plate 22 of the feed trough 5 and the elastic lip 24 are connected to the earth. The feed roller 6 and the contact surface 28 have a different potential. Both metal parts that establish contact between the feed roller 6 and the base body 21 or the protective plate 22 of the feed tray 5 or the elastic lip 24 and foreign bodies that press the elastic lip 24 against the contact surface 28 can be detected.

Finally shows Figure 8 a schematic front view of a feed tray 5. The elastic lip 24 is divided into four segments 24.1, 24.2, 24.3 and 24.4. Of course, a different number of segments is also possible. The individual segments are shorter than a single elastic lip 24 and can thus be adjusted better over their width.

The individual segments of the elastic lip 24 are also electrically isolated from one another. For this purpose, an insulation layer 34 is applied in the area in which they adjoin one another, only one of which has been provided with a reference symbol for the sake of clarity. The individual segments are each connected to the voltage source via a current measuring device. In the case of a foreign body or metal part in the fiber mat, it can thus be recognized in which segment this foreign body or this metal part is located. This is preferably indicated to the operating personnel so that the operating personnel can immediately search for the foreign body in the correct segment and then remove it.

The present invention is not limited to the illustrated and described exemplary embodiments. Modifications and combinations of features within the scope of the patent claims are possible, even if these are shown and described in different exemplary embodiments.

List of reference symbols

1

Card

2

Fiber mat

3

Feed plate

4th

Feeding device

5

Food tray

6th

Feed roller

7th

Lickerin

8th

Reel

9

cover

10

Doffer roller

11

Compression unit

12th

Card sliver

13th

Voltage source

14th

Current measuring device

15th

alarm

16

Control device

17th

warehouse

18th

axis

19th

Bearing ring

20th

Main body

21

Base body

22nd

Fender

23

Spacer bar

24

Elastic lip

24.1 - 24.4

Segments of the elastic lip

25th

Support bar

26th

Space

27

poetry

28

Contact area

29

Electric Isolation

30th

Further current measuring device

31

Piezoelectric element

32

Linkage

33

holder

34

Insulation layer

Claims (14)

1. A feeding device for feeding fiber flocks into a spinning preparation machine, comprising a feed roller (6), a feed trough (5), and an open electric circuit with a voltage source (14), wherein the electric circuit can be closed by a piece of metal contaminating the fiber flocks, characterized in that the open ends of the circuit are formed by the feed roller (6) and the feed trough (5) and that the feed trough (5) is electrically insulated from the feed roller (6), wherein the bearing (17) of the feed roller (6) is the insulator, and that an elastic lip (24) is associated with the feed trough (5), the feed trough (5) has a contact surface (28), and means are provided for detecting a contact between the elastic lip (24) and the contact surface (28).
2. The feeding device as set forth in the preceding claim, characterized in that the entire bearing (17) of the feed roller (6) and/or a bearing ring (19) of the bearing (17) is made of an electrically insulating plastic.
3. The feeding device as set forth in claim 1 or 2, characterized in that the means for detecting a contact comprise an electrical insulation (29) between the elastic lip (24) and the contact surface (28), with a voltage existing between the elastic lip (24) and the contact surface (28) and with the contact between the elastic lip (24) and the contact surface (28) being detected as a result of the closing of a circuit.
4. The feeding device as set forth in any one of the preceding claims, characterized in that the electric potential of the feed trough (5) is equal to the electric potential of the contact surface (28), and the electric potential of the feed roller (6) is equal to the electric potential of the elastic lip (24) but different from the electric potential of the feed trough (5).
5. The feeding device as set forth in any one of the preceding claims, characterized in that the electric potential of the feed trough (5) is equal to the electric potential of the contact surface (28) and the feed trough (5), the feed roller (6), and the elastic lip (24) each have a different electric potential.
6. The feeding device as set forth in any one of the preceding claims, characterized in that the means for detecting a contact comprise a piezoelectric element (31), the piezoelectric element (31) being provided on the elastic lip (24) and/or on the contact surface (28).
7. The feeding device as set forth in any one of the preceding claims, characterized in that a seal (27) is arranged between the elastic lip (24) and the contact surface (28).
8. The feeding device as set forth in any one of the preceding claims, characterized in that a preferably interchangeable and/or adjustable spacer strip (23) is arranged between a the base body (21) of the feed trough (5) and the elastic lip (24).
9. The feeding device as set forth in any one of the preceding claims, characterized in that the elastic lip (24) is made of steel, particularly chromium steel, and a wall thickness of the elastic lip (24) at its front end is preferably between 1.0 mm and 4.0 mm, especially preferably between 1.5 mm and 2.0 mm.
10. The feeding device as set forth in any one of the preceding claims, characterized in that the contact surface (28) is associated with a support strip (25), the support strip (25) being preferably made of aluminum.
11. The feeding device as set forth in any one of the preceding claims, characterized in that the feed trough (5) is divided into at least two segments (24.1 - 24.4) along its working width, an elastic lip (24) being associated with each segment (24.1 - 24.4).
12. The feeding device as set forth in claim 11, characterized in that a piezoelectric element (31) is associated with each segment (24.1 - 24.4) or the elastic lips (24) that are associated with the individual segments (24.1 - 24.4) are electrically insulated from one another and associated with separate circuits.
13. The feeding device as set forth in any one of the preceding claims, characterized in that the feeding device (4) comprises an acoustic and/or optical alarm (15) that is triggered when contact occurs between the elastic lip (24) and the contact surface (28) and/or the circuit between the feed roller (6) and the feed trough (5) and/or the elastic lip (24) is closed.
14. The feeding device as set forth in any one of the preceding claims, characterized in that the feeding device (4) comprises a control device (16) that interrupts the feeding of the fiber flocks, stops the feed roller (6), and preferably rotates the feed roller (6) back by a predetermined or predeterminable angle upon contact between the elastic lip (24) and the contact surface (28) and/or in the event of a closed circuit between the feed roller (6) and the feed trough (5) and/or the elastic lip (24).

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