EP3631059B1 - Drum for a carding machine - Google Patents

Description

The invention relates to a drum for a card with a thick, cylindrical drum shell, which is connected in the interior to at least two spokes running in the radial direction, which are arranged at a distance from one another as seen in the axial direction of the drum.

In order to achieve the most efficient carding effect possible with a card, it is necessary to keep the carding gap as small as possible, particularly in the main carding zone between the clothing of the flat and the clothing of the card drum (also called tambour). The clothing of the card drum is attached to the outer circumference of the card drum by special mounting and fastening methods.

In order to achieve high production quantities, the speeds of the card drums have been increased more and more in recent years. This means that card drums with speeds of over 600 rpm are now being used.

By increasing the speed, the centrifugal forces on the drum of the card (carding drum) are increased, which bring about uneven elastic deformations in the diameter area of the drum of the card due to the uneven tensions that occur.

Due to the described non-uniform elastic deformations occurring in the drum area, the carding gap set in the idle state can change in the operating state, which can lead to carding deterioration due to loss of carding surface as well as collisions of the clothings and thus damage to the clothings.

To counteract this, various solutions have already been proposed in the patent literature. In the EP 0 446 006 A1 the use of a drum for a card is proposed, which consists of a large number of lightweight profiles. With this design, the mass of the drum and thus the centrifugal forces that occur can be reduced under certain circumstances.

However, it is very complex and expensive and also requires time-consuming assembly work.

Furthermore, in the DE 10 2004 035 771 A1 an embodiment is proposed, wherein the drum of the card consists at least partially of steel or aluminum, which is covered with a bandage of carbon fiber reinforced plastic. On the one hand, this is intended to influence the thermal expansion and, on the other hand, to reduce the mass with regard to the centrifugal forces that occur. This embodiment is also relatively complex and expensive to manufacture.

the EP 0 214 438 A2 discloses an embodiment of a drum for a card which is internally divided into cells by radial support elements connected to the mantle of the drum. the SU 874 778 A1 discloses a reduced wall thickness of the drum shell in the area of the spokes, but ribs are provided inside the drum to which the spokes are attached. Additional rib-like reinforcements are provided between the spokes in the inner area of the drum casing. the GB 762 453 A discloses the attempt to reduce the deformation of the drum shell by a costly reinforcement of the width of at least one of the spokes. the U.S. 5,920,961A discloses a drum which is internally provided with longitudinal ribs in the direction of the drum axis. A disadvantage of these known designs of drums of the card is that an improvement in the dimensional stability or dimensional stability of the drum can only be achieved at the expense of high material costs or a complex construction.

It is therefore the object of the invention to propose a device which eliminates the disadvantages of the known prior art and also enables higher drum speeds for the card without undesired uneven deformations occurring in the region of the drum circumference of the card drum.

The object is solved by a drum having the features of the independent claim. A drum for a card is proposed with a thick, cylindrical drum shell, which is connected in the interior with at least two spokes running in the radial direction, which are arranged at a distance from one another as seen in the axial direction of the drum, the Wall thickness of the drum shell in the area of the connection to the respective spoke is greater than the wall thickness outside of this connection area, and the wall thickness of the drum shell - viewed in the axial direction of the drum - at least in the area between the spokes - starting from the connection area of the respective spoke - continuously reduced to a minimum wall thickness, the reduction in the wall thickness of the drum shell being continuous or curved.

This compensates for the centrifugal expansion over the entire longitudinal section. The wall thickness is reduced at an angle of 0.5 to 2.0 degrees, preferably 1.2 degrees.

With a simple and inexpensive design, the strength of the drum wall is also increased in the area between the spokes, which means that the drum wall is not deformed due to the centrifugal forces that occur in it Area is selectively distributed to allow an even centrifugal expansion.

Advantageously, it is proposed that the curve be made dependent on the local stresses, the shape of this curve containing a constant value of the stresses caused by the centrifugal force. In simplified form, one can speak of a parabolic curve.

It is further proposed that the greater dimension (d1) of the wall thickness of the drum shell in the connection area with the respective spoke is between 5.0 and 25.0 mm. Advantageously, it is further proposed that the minimum wall thickness (d2) of the drum casing (M) is between 2.0 and 15.0 mm. The wall thicknesses of the drum are thus dimensioned sufficiently to enable high speeds of the card drum without irregularities occurring in the carding gap due to increased centrifugal forces. With a drum diameter of more than 1.0 m and an axial length of more than 1.0 m, the minimum wall thickness is preferably 12.5 mm and the wall thickness in the connection area is 22.5 mm.

As a further embodiment of the invention, it is proposed that - seen in the axial direction of the drum - at least one section of the drum shell has the minimum wall thickness between the spokes, with the length of the section between 5 and 80% of the distance between the connecting area of two adjacent spokes is. To achieve a compact and stable construction of the drum, it is further proposed that—seen in the axial direction of the drum—the distance between the connecting area of two adjacent spokes is between 400 and 1300 mm.

The use of the drum according to the invention in a card is proposed.

Fig.1

eine schematische Seitenansicht einer Karde

Fig.2

eine schematische Schnittdarstellung A-A einer bekannten Kardiertrommel nach Fig.1

Fig. 3

eine schematische Schnittdarstellung einer Kardiertrommel nach Fig.2 mit einer erfindungsgemäss ausgebildeten Ausführung

Fig.4

eine weitere erfindungsgemässe Ausführung der Kardiertrommel nach Fig.3 in einer vergrösserten Teilansicht

Further advantages of the invention are shown and described in more detail using the following exemplary embodiments:

Fig.1

a schematic side view of a card

Fig.2

a schematic sectional view AA of a known carding drum Fig.1

3

a schematic sectional view of a carding drum Fig.2 with an embodiment designed according to the invention

Fig.4

another embodiment of the carding drum according to the invention Fig.3 in an enlarged partial view

1 shows a card 1 with a feed chute 2, via which the fibrous material is fed to a feed roller 3 in the form of a fiber web. The fiber material is delivered from the feed roller 3 to a licker-in 4, which transfers the fiber material to a carding drum 5 (called "drum" for short) of the card 1. The fiber material entrained by the drum 5 reaches the area of a main carding zone 7, which is formed in cooperation with a revolving flat unit 6 arranged circumferentially above the drum 5, as a result of the rotary movement of the drum 5 about its axis (shaft W), represented by an arrow. The direction of rotation of the revolving flat unit 6 is indicated by an arrow. The revolving flat unit 6 is provided with circulating flat rods D, shown schematically, which are equipped with clothings, not shown.

Following the main carding zone 7, the carded fiber material reaches the area of a rotatably mounted doffer 8, which removes the material removed from the drum 5 Fibrous material is transferred to a rotatably mounted doffing roller 9 . The doffer roller 9 conveys the fibrous material removed from the doffer 8 via guide devices (not shown) to a downstream pair of press rollers 10, which delivers the fibrous material to a fleece funnel 11 via additional guide means (e.g. a cross conveyor belt) that are not shown. The fiber material formed in the fleece funnel 11 (in the form of a sliver) is calendered by a subsequent pair of calender rollers 12 and transferred to a sliver coiler (not shown).

In Fig.2 is a sectional view AA of the drum 5 Fig.1 shown. The drum 5 is equipped on its outer peripheral surface U1 with a set G, which in the Fig.2 is indicated schematically. The drum 5 is rotatably mounted in a machine frame of the card via a shaft W and via the bearings L1, L2. The shaft W is connected to a card drive, which is not shown in detail. The already known drum 5 shown here has a cylindrical drum shell M with a constant wall thickness a. The drum jacket M is supported in its interior IR by spokes S1, S2 (also called drum base) arranged at an axial distance b from one another on the shaft W and is connected to it in a rotationally fixed manner. The spokes S1, S2 are attached to the inner peripheral surface U2 of the drum shell M in a peripheral connection area V1, or V2. The attachment can be done by welds (schematically indicated), by a press fit or in some other way. It is also possible to form the spokes S1, S2 in one piece with the drum casing (eg by a casting process).

In Fig.3 the longitudinal section of a drum 5 is shown, which shows an exemplary embodiment of a drum casing M designed according to the invention with spokes S3, S4 arranged in its interior IR. The drum jacket M has a wall thickness d1 in the area of the connection areas V1, V2 with the respective spokes S3, S4. Starting from the respective connection area V1, V2--seen in the axial direction of the drum 5--the wall thickness of the drum jacket M on both sides of the connection areas V1, V2 is continuously reduced down to a minimum wall thickness d2. The inner peripheral surface U2 runs at an angle c1 or c2, starting from the inner surface IF of the respective connection area V1, V2. The angles c1 and c2 can be different or have the same value. In the present embodiment Fig.3 a section T of the drum casing M with a length s is provided with a constant wall thickness d2.

As in the embodiment of Fig.2 are also described in the embodiment of FIG Fig.3 the spokes S3, S4 are arranged at an axial distance b from one another and are supported on a shaft W, to which they are connected in a rotationally fixed manner. The shaft W is rotatably mounted in a machine frame via the bearings L1, L2 and is connected to a drive (not shown).

Through the in the example of Fig.3 shown continuous reduction in the wall thickness of the drum shell, starting from the respective connection area V1, V2 of the spokes S3, S4, the centrifugal forces acting on the drum shell M during operation are absorbed better and dissipated accordingly, so that it is particularly in the area between the spokes S3, S4 to fewer formations in the diameter range.

The enlarged view of the Fig.4 shows a section of the drum Fig.3 , In a further exemplary embodiment, the reduction in wall thickness d1 in the respective connection region V1 runs in the form of a curve P down to a minimum wall thickness d2. This design enables optimal absorption or dissipation of the centrifugal forces that occur in the drum shell M during operation.

However, another embodiment is also possible within the scope of the invention, with the wall thickness of the drum casing M in the area of the drum casing M between the spokes S3, S4, starting from the respective connection area V1, V2, changing in the form of a parabola ( Fig.4 ) tapers, while in the area of the drum shell M, which points from the respective spoke S3, S4 to the respective end face of the drum, the tapering of the wall thickness of the drum shell decreases continuously, as in the example of Fig.3 was shown.

There are other versions possible, where z. B. no central section T is provided with a constant wall cross-section. In other words, in this case, the tapering of the wall thickness of the drum jacket M would lead to the middle of the drum, starting from the connection areas V1, V2.

Reference sign

1

card

2

feed chute

3

food roller

4

licker

5

carding drum (drum)

6

revolving flat unit

7

main carding zone

8th

customer

9

doffer roller

10

pair of press rollers

11

fleece funnel

12

pair of calender rolls

D

flat bar

G

set

IF

Inner surface

IR

inner space

M

drum shell

P

parabola

S1 - S4

spoke

T

section

U1

Outer perimeter

U2

inner peripheral surface

V1, V2

connection areas

W

Wave

a

jacket thickness

b

Spacing spokes

c1, c2

angle

d1

Wall thickness

d2

minimum wall thickness

s

Length section

Claims (8)

1. A drum (5) for a carding machine (1), comprising a cylindrical drum shell (M) that has a wall thickness (a, d1, d2) and is connected in the interior space (IR) to at least two spokes (S1, S2, S3, S4) that run in a radial direction and are arranged at a distance (b) from one another, as seen in the axial direction of the drum (5), in which the wall thickness of the drum shell (M) is of a greater dimension (d1) in the area of the connection (V1, V2) from the respective spoke (S3, S4) than the wall thickness outside of this connecting area (V1, V2), in that the wall thickness (d1) of the drum shell - as seen in the axial direction of the drum - decreases to a minimum wall thickness (d2) - at least in the area between the spokes (S3, S4) - starting from the connecting area of the respective spoke, characterized in that the reduction in wall thickness of the drum shell (M) is continuous or in the form of a curve.
2. The drum (5) for a carding machine according to claim 1, characterized in that the wall thickness of the drum shell (M) - as seen in the axial direction of the drum - decreases continuously to a minimum wall thickness (d2) - on both sides of the respective connecting area (V1, V2) - starting from the respective spoke (S3, S4).
3. The drum (5) for a carding machine (1) according to claim 4, characterized in that the reduction in wall thickness of the drum shell (M) is in the form of a parabola (P).
4. The drum (5) for a carding machine (1) according to any one of the preceding claims, characterized in that the greater dimension (d1) of the wall thickness of the drum shell (M) in the connecting area (V1, V2) with the respective spoke (S3, S4) is between 5.0 mm and 25.0 mm.
5. The drum (5) for a carding machine (1) according to any one of the preceding claims, characterized in that the minimum wall thickness (d2) of the drum shell (M) is between 2.0 mm and 15.0 mm.
6. The drum (5) for a carding machine (1) according to any one of the preceding claims, characterized in that at least one partial section (T) of the drum shell (M) has a minimum wall thickness (d2) - as seen in the axial direction of the drum (5) - between the spokes (S1, S2), such that the length (s) of the partial section (T) amounts to between 5% and 80% of the distance (b) between the connecting area (V1, V2) of two connecting spokes (S3, S4).
7. The drum (5) for a carding machine (1) according to any one of the preceding claims, characterized in that the distance (b) between the connecting area (V1, V2) of two neighboring spokes (S3, S4) is between 400 mm and 1300 mm - as seen in the axial direction of the drum.
8. The carding machine (1) having a drum (5) according to any one of the preceding claims.

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