CN110869549A

CN110869549A - Feeding device

Info

Publication number: CN110869549A
Application number: CN201880039142.5A
Authority: CN
Inventors: P.杰里耐克; H.斯图德尔
Original assignee: Maschinenfabrik Rieter AG
Current assignee: Maschinenfabrik Rieter AG
Priority date: 2017-04-13
Filing date: 2018-01-31
Publication date: 2020-03-06
Anticipated expiration: 2038-01-31
Also published as: CH713692A1; WO2018189595A1; CN110869549B; EP3610058A1; EP3610058B1

Abstract

The invention relates to a feeding device (4) for feeding fibre flocks into a spinning preparation machine, comprising a feeding roller (6), a feeding channel (5) and an open circuit (14) with a voltage source, which is closed by a metal piece contaminating the fibre flocks. According to the invention, it is proposed that the open end of the electrical circuit is formed by the feed roll (6) and the feed chute (5), and that the feed chute (5) is electrically insulated from the feed roll (6), wherein the bearing (17) of the feed roll (6) is preferably an insulator.

Description

Feeding device

Technical Field

The invention relates to a feeding device for feeding fibre flocks into a spinning preparation machine, comprising a feeding roller, a feeding chute and an open circuit with a voltage source, which can be closed by a metal piece contaminating the fibre flocks.

Background

From GB 465,899, a spinning preparation machine is known, which has a device for detecting metal parts in a fibrous material. These devices comprise a pair of rollers through which the fibrous material passes. The rollers are arranged at a distance from each other. Further, the rollers are arranged in an electric circuit, wherein the electric circuit is closed when the metallic foreign matter closes the gap between the two rollers. When the circuit is closed, the fibrous material stops or moves backwards.

One disadvantage of this solution is the need for a pair of rollers which, on the one hand, adversely affect the fibre flow and, on the other hand, have to be cleaned and maintained regularly.

Disclosure of Invention

It is therefore an object of the present invention to provide a feeding device which detects metal pieces without an additional pair of rollers.

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

A feeding device for feeding fibre flocks into a spinning preparation machine is proposed. The spinning preparation machine may be a carding machine or a cleaner. The feeding device comprises a feeding roller, a feeding groove and an open circuit with a voltage source. The circuit can be closed by a piece of metal contaminating the lint. Instead, a closed circuit indicates a metal piece contaminating the lint.

According to the invention, the open end of the circuit is formed by the feed roller and the feed groove. I.e. two elements of the feed device already present are used for detecting the metal pieces. No other mechanical parts are required that disturb the fiber flow and that have to be cleaned and maintained.

Advantageously, the feed chute is electrically insulated from the feed roll. An open circuit can then be formed in which the feed chute and feed rollers are open ended. The bearing of the feed roll is an insulator. Insulation can be accomplished with little effort. Advantageously, the bearing is provided with an insulating coating. Particularly preferably, the entire bearing of the feed roll and/or the bearing ring of the bearing is made of an electrically insulating plastic. Depending on the size and mechanical requirements of the feed roll, one of the two variants may prove to be more advantageous.

As an alternative to the above described embodiment, the bearing shell is made of plastic. The bearing shell is the part that encloses the bearing ring and is provided with fastening means to the machine. Furthermore, the bearing body, which, for example in a ball bearing, consists of a single ball held in a bearing cage, can also be made of ceramic. The ceramic ball has the necessary operational properties while being electrically insulating. A further alternative to electrical insulation may be achieved by mounting appropriate supports between the bearings of the feed roll and the machine or between the bearings and the feed roll itself, for example by coating or selecting an appropriate material for the feed roll shaft at the point where the feed roll is held at the bearings.

In an advantageous development of the feed device, the feed chute is associated with an elastic lip. The resilient lip forms a gap between itself and the feed roll. Furthermore, the feed chute has a contact surface and means are provided for detecting contact between the resilient lip and the contact surface. If the elastic lip is deformed by foreign matter, it comes into contact with the contact surface if the size of the foreign matter, and thus the elastic deformation, is large enough. The contact, and thus the foreign matter, is detected by using the means for detecting contact. Therefore, the non-metallic foreign matter is also detected by the contact of the elastic lip portion with the contact surface.

Alternatively, the means for detecting contact may comprise a piezoelectric element. The piezoelectric element is cheap, reliable and largely maintenance-free. The piezoelectric element may be provided on the resilient lip and/or on the contact surface. In the case of contact between the elastic lip and the contact surface, a pressure is then exerted on the piezoelectric element, which in turn results in a voltage being detected by the sensor system.

It is furthermore advantageous that the means for detecting contact comprise an electrical insulation between the resilient lip and the contact surface. A voltage is present between the resilient lip and the contact surface and contact between the resilient lip and the contact surface is detected as a result of the closing of the electrical circuit. This makes it easy and cheap to detect the contact between the resilient lip and the contact surface, and the electronics required for this are cheap and robust.

Advantageously, the potential of the feed chute is equal to the potential of the contact surface and the potential of the feed roll is equal to the potential of the resilient lip but different from the potential of the feed chute. Thus, the voltage source can be used to detect the metal piece between the feed roll and the feed chute and the contact between the resilient lip and the contact surface caused by foreign matter. The voltage generated by the voltage source is preferably between 1.5V and 32V, particularly preferably between 12V and 28V. On the one hand these voltages are easy to generate and on the other hand they do not require very sensitive detectors. Furthermore, the voltage is small enough to not pose a threat to the health of the operator in case the operator comes into contact with one or both of the electrodes.

It is furthermore advantageous if the potential of the feed chute is equal to the potential of the contact surface and the feed chute, the feed roller and the resilient lip each have a different potential. Although this means that three different potentials are required, it also means that, contrary to the above, contact between the resilient lip and the feed roll caused by the metal element can be detected. A metal piece may have been detected if such a metal piece has not deformed the resilient lip to such an extent that it is brought into contact with the contact surface. The voltage (i.e. the potential difference) is again within the above range.

The resilient lip and the contact surface form an opening to the cavity, which opening especially enables the resilient lip to move. To prevent the cavity from being contaminated, a seal is advantageously arranged between the resilient lip and the contact surface. The seal may be deformed to such an extent that it may be over-compressed during deformation of the resilient lip, thereby preventing electrical contact between the resilient lip and the contact surface or pressure on the piezoelectric element, respectively.

Advantageously, the spacer bar is arranged between the body and the resilient lip of the feed chute. This makes it possible to set a distance between the basic body and the elastic lip, which is optimal for gripping the fibrous material. In order to enable this distance to be adapted to different fibre lengths, the spacer bars are preferably exchangeable and/or adjustable. For particularly large fiber lengths of greater than about 28 mm, the spacer bars can also be omitted altogether.

It is advantageous that the resilient lip is made of steel, in particular chrome steel, because these materials have a good resilience and a good spring strength. Chromium steel is also corrosion resistant. The wall thickness of the resilient lip at its front end is preferably between 1.0mm and 4.0mm, particularly preferably between 1.5mm and 2.0mm, as this provides the necessary spring strength.

Advantageously, the contact surface is associated with a support strip. The support strip is arranged at a distance from the elastic lip such that it can be closed by elastic deformation of the elastic lip. If no brace bar is present, a large foreign object may deform the resilient lip so far that it leaves the resilient range and then no longer returns to its previous shape. The brace bars prevent this and can thus extend the service life of the resilient lip. One particularly suitable material for the support bar is aluminum, since aluminum provides high dimensional stability and is lightweight.

Advantageously, the feed chute is divided into at least two sections along the working width of the feed chute, in which case an elastic lip is associated with each section. This simplifies the adjustment of the gap created by the resilient lip, since it is no longer necessary to set a constant gap width over the entire working width.

Advantageously, the elastic lips associated with each segment or with the individual segments of the piezoelectric element are electrically insulated from each other and associated with separate electrical circuits. Thus, each segment can detect foreign matter separately. If this is indicated to the operator, the search for foreign bodies is then simplified and therefore foreign bodies can be removed more quickly and production can be continued more quickly.

It is furthermore advantageous if the feed device comprises an acoustic and/or optical alarm, which is triggered when contact between the elastic lip and the contact surface occurs and/or when an electrical circuit between the feed roll and the feed chute and/or the elastic lip is closed. If metal pieces and/or another foreign body contaminating the lint are detected, an alarm is triggered accordingly. In this way, the operator is warned of metal pieces and/or foreign objects. The operator may then stop production and/or remove metal pieces or foreign matter.

Finally, it is advantageous if the feeding device comprises a control device which interrupts the feeding of the flock and stops the feeding roller upon contact between the elastic lip and the contact surface and/or in the event of a closed electrical circuit between the feeding roller and the feed chute and/or the elastic lip. Advantageously, the disconnection is controlled directly by the feed roll drive or its frequency converter. This means that the feed roll can be immediately disconnected. In modern feeding devices, the surface of the feed roll can be advanced only 10mm from the point in time when the metal piece or foreign body is detected before standstill. In this way, damage to the feed rolls and the feed chute can be largely prevented. The signals are transmitted from the control device of the feed roll drive to a central control unit, which disconnects the power supply.

In order to achieve a higher operational safety, it is advantageous to activate the opening of the feed device or the feed roller in the case of a contact between the elastic lip and the contact surface and/or a closed circuit between the feed roller and the feed chute and/or the elastic lip depending on the lifting of the feed roller. This means that the disconnection is not effective if there is no feed, which means that erroneous switching, for example due to vibrations when the machine is unloaded, can be avoided.

Preferably, the control device rotates the feed roller backward at a predetermined or predeterminable angle after the feed roller is stationary. In this case, the angle is set such that a metal piece or foreign matter enters the area from which the operator can easily remove the metal piece or foreign matter.

The features cited may be present alone or in any combination according to the previous description of the realisation of the feeding device.

Drawings

Further advantages of the invention are described in the following exemplary embodiments. In the drawings:

figure 1 shows a schematic side view of a carding machine,

figure 2 shows a schematic side view of a feeding device,

figure 3 shows a schematic cross section through the bearing of the feed roll,

figure 4 shows a schematic cross section through another bearing of the feed roll,

figure 5 shows a schematic side view of another feeding device,

figure 6 shows a schematic side view of another feeding device,

FIG. 7 shows a schematic side view of another feeding device, an

Fig. 8 shows a schematic front view of the feed chute.

Detailed Description

Fig. 1 shows a schematic side view of a carding machine 1. The fibres are transported in the carding machine 1 from left to right. The fibre layer 2 first passes the feed plate 3 and then enters the feed device 4. The feed device 4 has a feed chute 5 cooperating with a feed roll 6. The fibre layer 2 gripped between the feed chute 5 and the feed roll 6 is then fed to the spike roll 7.

The fibrous nonwoven continues from the lickerin roll 7 to the cylinder 8 and is further processed between the cylinder 8 and the cover 9, which is shown very schematically here. The fibrous nonwoven is then removed from the doffing roller 10 and transferred to a compacting unit 11, where it is compacted into carded sliver 12.

Fig. 2 shows a schematic side view of a feeding device 4 according to the invention. The feed device 4 may be part of the carding machine 1 shown in fig. 1, but it may also be part of a carding machine or cleaner. The feeding device 4 has a feeding chute 5 and a feeding roller 6. In addition, a part of the lickerin roll 7 is also shown.

The feed chute 5 and the feed rollers 6 are arranged as open ends in an open circuit. For example, the feed roll 6 may be electrically connected by its shaft. The circuit further comprises a voltage source 13 and a current measuring device 14. The circuit is also closed if the gap between the feed chute 5 and the feed roll 6 is closed by metal pieces contaminating the flock. Then, the current detected by the current measuring device 14 flows. The current detected by the current measuring device 14 is thus indicative of the metal piece between the feed launder 5 and the feed roll 6.

In order to report the current and thus the detection of metal pieces, the current measuring device 14 is connected to an acoustic and/or optical alarm 15, which alerts the operator to the presence of metal pieces.

Advantageously, the current measuring device 14 is also connected to a control device 16, said control device 16 stopping the feed rollers 6 when a metal piece is detected, so that the metal piece does not make any further penetration, preventing it from causing any major damage. It is particularly advantageous that the control device 16 also rotates it back far enough after the feed roll 6 has stopped, so that the metal pieces below the feed launder 5 are exposed and can be easily removed by the operator.

In order to keep the circuit open, the feed chute 5 and the feed roll 6 must be electrically insulated from each other. This insulation can be achieved by means of the electrically insulating bearings 17 of the feed roll 6 shown in cross-section in fig. 3. The electrical insulation of the bearing 17 can be achieved by coating the bearing surfaces accordingly. In the exemplary embodiment of fig. 3, the entire bearing 17 of the feed roll 6 is made of electrically insulating plastic. The shaft 18 of the feed roll 6 is thus electrically insulated from the bearing 17 and other parts of the feed device 4.

In the alternative exemplary embodiment of fig. 4, only the bearing ring 19 of the bearing 17 is made of electrically insulating plastic, while the main body 20 of the bearing 17 may also be electrically conductive. Also in this case, the shaft 18 of the feed roll 6 is electrically insulated from the bearing 17 and other parts of the feed device 4.

In the following description of alternative exemplary embodiments, the same reference numerals are used for features that are the same and/or at least comparable with other embodiments in terms of their construction and/or mechanism of action. Without going into further detail, their construction and/or mechanism of action correspond to the construction and mechanism of action of the features already described above.

In the exemplary embodiment shown in fig. 5, only a part of the feed roll 6 is shown to make the details of the feed chute 5 more evident. Furthermore, the electrical connection to the feed roll 6 is only very schematically shown, but as mentioned before it may occur via the shaft of the feed roll 6.

In the exemplary embodiment, the feed chute 5 has a main body 21, said main body 21 being partially protected from wear by a protective plate 22. In addition, a spacer 23 is arranged on the base body 21 in order to enable an optimum spacing between the base body 21 and the elastic lip 24. The spacer bars 23 are designed to be interchangeable so that they can be adapted to the respective fiber length. For very long fibers, the spacer 23 may even be omitted entirely.

The resilient lip 24 is arranged such that it can grip the fibre between the resilient lip 24 and the feed roll 6. In addition, a supporting strip 25 is arranged on the side of the feed roll 6 remote from the elastic lip 24. The resilient lip 24 is resiliently deformable to the extent that it contacts the support strip 25. Due to the support strip 25 further deformation of the resilient lip 24, for example due to hard foreign bodies in the fibre material, is excluded. Thus, in particular, the elastic lip 24 is not deformed in the region where the permanent deformation occurs. Thus always ensuring that the resilient lip 24 returns to its original shape and position.

In order to protect the gap 26 between the resilient lip 24 and the support strip 25 from contamination, in particular from lint, an easily deformable sealing member 27 is arranged between the resilient lip 24 and the support strip 25.

In order to detect hard foreign objects pressing the resilient lip 24 against the contact surface 28 of the support strip 25, the resilient lip 24 and the support strip 25 are also arranged in the circuit. To this end, the electrical insulation 29 first insulates the resilient lip 24 from the support strip 25.

The circuit in this exemplary embodiment is constructed such that the voltage source 13 supplies positive (+ U) and negative (-U) voltages in addition to ground (0V). The amount of positive and negative voltages need not be the same and other explicit indications of voltage sources are possible. A positive voltage is applied to the resilient lip 24, a negative voltage is applied to the feed roll 6, and the support strip 25 and the base 21 and/or the guard plate 22 of the feed chute 5 are connected to ground.

As described above, the metal member closes the electric circuit, the metal member contaminates the lint, the feed chute 5 is brought into contact with the feed roller 6, and the current measuring device 14 detects the flow of the current. However, if the elastic lip 24 is deformed by a hard foreign substance, for example, to such an extent that it contacts the contact surface 28 of the support rod 25, then another circuit is closed and a current flows, which is measured by another current measuring device 30. Even smaller pieces of metal can be detected which cannot produce any contact between the feed roll 6 and the body 21 of the feed chute 5 but between the feed roll 6 and the resilient lip 24. In this case, the circuit is closed, which results in a current flowing through the current measuring device 14 and the additional current measuring device 30. The current flow through the two

current measuring devices

14 and 30 is thus indicative of the metal piece between the feed roll 6 and the resilient lip 24.

In this figure, the illustration of the alarm 15 and the control device 16 has been omitted for clarity. Preferably, however, the measured values of both

current measuring devices

14 and 30 will be used by the control device 16 to trigger the alarm 15 and stop and/or retract the feed roll 6. Thus, for example, an alarm may be sounded by a different tone, color, or other representation to indicate the area in which the metallic article and/or foreign object was detected. The angle at which the feed roll is retracted after stopping may also be selected as a function of the area in which metal pieces or foreign matter is detected. For example, the angle of the metal piece that has triggered contact between the feed roller 6 and the body 21 of the feed chute 5 needs to be less than the angle of a foreign object that merely causes the resilient lip 24 to contact the contact surface 28 of the support strip 25.

In an exemplary embodiment not shown here, the feed roll 6 and the elastic lip 24 have the same potential. Thus, a simpler voltage source 13 can be used. However, it is no longer possible to measure the electrical contact between the feed roll 6 and the elastic lip 24 triggered by the smaller metal pieces.

In the exemplary embodiment shown in fig. 6, the contact between the elastic lip 24 and the contact surface 28 is detected by a piezoelectric element 31. In this case, the piezoelectric elements 31 are arranged on the contact surfaces 28 of the support strips 25, but may also be arranged on the resilient lips 24. Upon contact between the elastic lip 24 and the contact surface 28, pressure is applied to the piezoelectric element 31, thereby generating a voltage between the two electrodes of the piezoelectric element 31. In this way the voltage is measured and a contact is detected.

The circuit for detecting the metal pieces between the feed roll 6 and the feed launder 5 has a design similar to the circuit shown in fig. 2. The alarm 15 (not shown here) and the control device 16 are also advantageously connected to the measuring device of the piezoelectric element 31 so that a distinguishable alarm can be triggered and/or the feed roll can be optimally stopped and/or retracted.

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

In the feed chute 5 shown in fig. 7, the spacer bars 23 are realized as adjustable tie rods 32. Thus, it can be adapted to different fiber lengths without expensive conversion.

In addition, no support bars are provided in the exemplary embodiment of fig. 7. The contact surface 28 is arranged on an electrically insulating holder 33. As a result, no separate insulation of the resilient lip 24 is required. As a possible electrical circuit, the body 21 and the protection plate 22 of the feed chute 5 and the elastic lip 24 are here connected to ground. The feed roll 6 and the contact surface 28 have a different electrical potential than them. Therefore, it is possible to detect not only the metal pieces that cause contact between the feed roller 6 and the feed chute 5 or the main body 21 of the elastic lip 24 and the shield plate 22, but also foreign substances that press the elastic lip 24 against the contact surface 28.

Finally, fig. 8 shows a schematic side view of the feed chute 5. The resilient lip 24 is divided into four sections 24.1, 24.2, 24.3 and 24.4. As will be readily appreciated, different numbers of sections are also possible. Each segment is shorter than a single resilient lip 24 and can therefore be better adjusted in its width.

The various sections of the resilient lip 24 are also electrically isolated from one another. For this purpose, the insulating layers 34 are applied in regions where the insulating layers 34 adjoin one another, only one of which is provided with a reference numeral for the sake of clarity. Each segment is connected to a voltage source by a respective current measuring device. If foreign bodies and/or metal parts are present in the fibre layer, the section in which the foreign bodies and/or metal parts are located can thus be identified. This is preferably reported to the operator, so that the operator can immediately search for foreign bodies in the correct section and then remove them.

The invention is not limited to the exemplary embodiments which have been illustrated and described. Even though illustrated and described in different exemplary embodiments, the combination of features may be modified within the scope of the claims.

List of reference numerals

1 carding machine

2 fibrous layer

3 feeding plate

4 feeding device

5 feed chute

6 feeding roller

7 licker-in

8 cylinder

9 cover

10 doffing roller

11 pressing unit

12 card sliver

13 voltage source

14 current measuring device

15 alarm

16 control device

17 bearing

18-shaft

19 bearing ring

20 main body

21 base body

22 protective plate

23 space bar

24 resilient lip

24.1-24.4 sections of elastic lips

25 support strip

26 gap

27 seal

28 contact surface

29 electrical insulation

30 additional current measuring device

31 piezoelectric element

32 connecting rod

33 holder

34 insulating layer.

Claims

1. A feeding device for feeding lint into a spinning preparation machine, comprising a feeding roller (6), a feeding chute (5) and an open circuit (14) with a voltage source, wherein the circuit can be closed by a metal piece contaminating the lint, characterized in that the open end of the circuit is formed by the feeding roller (6) and the feeding chute (5), and the feeding chute (5) is electrically insulated from the feeding roller (6), wherein the bearing (17) of the feeding roller (6) is an insulator.

2. Feeding device according to the preceding claim, characterized in that the entire bearing (17) of the feeding roll (6) and/or a bearing ring (19) of the bearing (17) is made of electrically insulating plastic.

3. Feeding device according to any one of the preceding claims, characterized in that an elastic lip (24) is associated with the feed chute (5), the feed chute (5) having a contact surface (28), and means are provided for detecting contact between the elastic lip (24) and the contact surface (28).

4. Feeding device according to claim 3, characterised in that the means for detecting contact comprise an electrical insulation (29) between the resilient lip (24) and the contact surface (28), wherein a voltage is present between the resilient lip (24) and the contact surface (28) and the contact between the resilient lip (24) and the contact surface (28) is detected as a result of the closing of an electrical circuit.

5. A feeding device according to any one of the preceding claims, characterised in that the potential of the feed chute (5) is equal to the potential of the contact surface (28) and the potential of the feed roll (6) is equal to the potential of the resilient lip (24) but different from the potential of the feed chute (5).

6. Feeding device according to any one of the preceding claims, characterised in that the potential of the feed chute (5) is equal to the potential of the contact surface (28) and if the feed chute (5), the feed roller (6) and the resilient lip (24) each have a different potential.

7. Feeding device according to claim 3, wherein said means for detecting contact comprise a piezoelectric element (31), said piezoelectric element (31) being arranged on said elastic lip (24) and/or on said contact surface (28).

8. Feeding device according to any one of the preceding claims, characterised in that a seal (27) is arranged between the resilient lip (24) and the contact surface (28).

9. Feeding device according to any one of the preceding claims, characterized in that preferably exchangeable and/or adjustable spacer bars (23) are arranged between the basic body (21) of the feeding chute (5) and the elastic lip (24).

10. Feeding device according to any one of the preceding claims, characterised in that the elastic lip (24) is made of steel, in particular chrome steel, and that the wall thickness of the elastic lip (24) at its front end is preferably between 1.5mm and 2.0 mm.

11. Feeding device according to any one of the preceding claims, characterised in that the contact surface (28) is associated with a support strip (25), the support strip (25) preferably being made of aluminium.

12. Feeding device according to any one of the preceding claims, characterised in that the feed chute (5) is divided into at least two sections (24.1-24.4) along its working width, an elastic lip (24) being associated with each section (24.1-24.4).

13. Feeding device according to claim 12, characterised in that a piezoelectric element (31) is associated with each segment (24.1-24.4) or in that the elastic lips (24) associated with the respective segments (24.1-24.4) are electrically insulated from each other and associated with a separate electric circuit.

14. Feeding device according to any one of the preceding claims, characterised in that the feeding device (4) comprises an acoustic and/or optical alarm (15) which is triggered when contact between the elastic lip (24) and the contact surface (28) occurs and/or the electrical circuit between the feeding roller (6) and the feeding channel (5) and/or the elastic lip (24) is closed.

15. Feeding device according to any one of the preceding claims, characterised in that the feeding device (4) comprises a control device (16), which control device (16) interrupts the feeding of the fibre flocks, stops the feeding roller (6) and rotates the feeding roller (6) backwards, preferably at 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 electrical circuit between the feeding roller (6) and the feeding channel (5) and/or the elastic lip (24).