EP1687467B2 - Adjustment of the carding machine elements to thermal expansion effects - Google Patents

Description

The invention relates to elements for a card, which, after a possible warm-up period in the production of card slivers in a given production, the desired surface shape, which guarantee an equal over the working width of the roller distance between the set of roller and the counter element.

Garnished rolls are used in many areas of spinning machines. These rollers usually have at least two roller blades or flanges on the end face, in which on the one hand the roller is rotatably mounted and which on the other hand may comprise support elements for receiving and / or supporting additional working elements. The working elements have in common that they are slightly longer than the working width of the roller, and rest on the left and right on the support elements, for example, segmental arch, top segments or (flexible) bows, which are also partially adjustable.

These working elements can be divided into two main groups: stationary working elements, which are arranged stationary, for example carding elements, shuttering elements, knives, grates, or guide elements, and moving working elements, which by means of an endless circulating belt, for example a chain or a belt, be pulled over the support surface of the support elements, for example, the cover of a card.

Rollers in spinning machines, in particular cleaning machines, for example cleaners or carding machines, are surrounded not only by shuttering segments but also by knives, grates, carding segments or guide elements. These may take the form of plates or rods, possibly provided with a garnish e.g. Sawtooth. have and they always have a side that is arranged opposite the clothing of the roller. The distance between this side and the clothing of the roller is set as precisely as possible. This setting affects, among other things, the carding quality and / or the amount of dirt removal, depending on the function of the element. Especially with the carding segments, a narrow distance increases the carding quality of the card and reduces the number of nits in the card sliver. An optimal setting is achieved when the desired distance during operation over the entire working width is the same. Since these settings are in the range of tenths of a millimeter, deviations of hundredths of a millimeter can already have a significant effect on the function of each segment. In addition, the wear duration is extended by the homogeneous loading of the elements over the entire working width.

However, this desired, fine adjustment over the entire width of the card is difficult to achieve. The thermal expansion and its influence on the various elements of the card will be explained in more detail below.

During commissioning of the card, i. in the production of the card sliver, the card goes through a warm-up period. The duration of the warm-up period and the heat generated is affected by the drum speed, the level of production, and the selected settings of the elements. At lower and high production, the warm-up time lasts approximately the same length; However, the heat generated is higher at high production. During this warm-up period, the various components expand due to heat. A high performance card will work with high production, resulting in additional heating. Especially tight settings between carding, lid or knife, and drum pose a danger because the elements can touch. For example: a desired carding gap between a carding element formed from an aluminum profile and the drum is 0.5 mm when cold - before the card is put into operation. At a production rate of 150 kg / h, the effective gap after the warm-up time of the carding machine is only 0.2 mm. This reduction of 0.3 mm is due to the thermal expansion of the drum surface and the carding surface and the thermal expansion of the working elements, as well as to the fiber / metal friction which occurs in the card belt production between the carding elements.

Out WO 79/00983 For example, a method of controlling working conditions in a card with two rotating drums is known. Among other things, the distance between the two drums is changed to compensate for heating. This change takes place by means of cylinders which are designed variable in length so that they can change the distance of the axes of the drums according to the present temperature. In another embodiment, a card with a drum and a revolving flat is shown instead of two drums. In this embodiment (Figure 3), the distance of the traveling lid assembly is changed from the axis of the drum with a cylinder. The detection of the respective temperature on the drum is carried out with a sensor which causes the change of the cylinder via a controller. A disadvantage of this device is the great effort that must be operated to control the system. There are sensors and control devices and adjusting elements required, which must be coordinated with each other, in order to effect a change in the distance of the drum from the traveling deck unit or the distance of the two drums from each other in accordance with predetermined conditions. A failure of the controls causes a false production, since the distance from the drum to traveling deck unit is no longer at the required distance and the fibers can not be carded with the required accuracy.

Out EP 0 077 166 A1 are devices for Cooling the drum of a card known. According to the disclosure of this document, an attempt is made to keep the drum at a certain surface temperature by means of liquid channels which are arranged inside the drum. This is to ensure that the temperature of the cylinder during operation of the card is kept substantially constant and thus the expansion of the drum with respect to a revolving flat is low or can be avoided. The disadvantage of such a design is that it is very expensive to introduce liquid into the interior of the drum. For this purpose, a hollow shaft is required in order to bring the liquid into the interior of the drum and to remove it again. In addition, the temperature of the liquid and / or the drum must be monitored in order to be able to react to the corresponding operating temperature. The illustrated solution of the problem is thus also very expensive to manufacture and maintain. Out EP 0 431 485 B1 and EP 1 031 650 Cards are known in which a solution of heat dissipation is sought.

The above-mentioned solutions have the disadvantage that they either offer only a solution over the entire width or only alleviate the heat effects, as is the case with cooling.

By warming up but not only creates a thermal expansion over the entire working width of the card, but it also creates thermal gradients on the embodiments of the various components of the card. For example, at the drum surface, a temperature of 45 ° C may arise. An arranged on the drum Festkardiersegment will also reach this temperature on the side of the drum set. On the other hand, the side of the carding segment facing away from the drum, which, due to the working width and the accuracy of the elements, has a height of several centimeters due to the design, the temperature reaches a much lower value (eg 28 ° C.) The difference in temperature over Festkardiersegment can thus be a few degrees Celsius. How big this temperature difference is depends on the nature of the segment (construction, material), the work of carding (speed, production), the distance of the element to the roll, and how the heat that is generated can be dissipated. In EP 1 031 650 An example is given of a card design that better dissipates the resulting heat.

This thermal gradient causes bending of the elements across the width of the card. This deflection creates a narrower carding gap in the middle than outside. This results in a non-uniform carding gap, which spreads to the outside. This leads to a reduced Kardierqualität and / or a poorer Schmutzausscheidung and / or a poorer Nissenauflösung. This can also lead to "side flight" of the fibers. This means that fibers accumulate in the peripheral regions, and / or even settle, especially outside the working width.

These effects are expressed in a standard card with a working width of 1 meter less. However, in the new generation of high-performance tarpaulins, the working width is greater than 1 meter, for example 1.5 meters. The deviation caused by the above-mentioned effects can not be neglected here, but are a problem for the carding quality of the card.

The invention has for its object to provide card elements of the type described input, which avoid the disadvantages mentioned, in particular, the elements of the card so that the heat effects are eliminated after the warming and constant Kardierabstände be achieved in a given production.

The solution of this object is achieved by the characterizing features of claim 1. Due to the design of the elements over the working width of the card as hollow profiles is achieved after the warm-up by the influence of temperature, for a given production, a profile shape that corresponds to a just-produced profile. The elements which are suitable for this are, in particular, the rollers, the covers of the revolving lids and the stationary working elements, for example knives, carding segments or guide elements.

The inventive solution is basically applicable to all the carding elements which have a surface which are or are in contact with fibrous material. These are both the working elements, for example carding segments, knives, tongue or cover, as well as all rolls, for example drum roll, doffer roll, licker-in roll.

By the term "hollow" is meant that the element on the side which can come into contact with the fibrous material, at least in one dimension of the element, is concave over the working width of the card, or in other words the element has a concave arch shape the working width of the card.

An example would be a hollow profile with a production of 60 kg / h and a drum speed of 850 min-1. This production is very often used for slivers intended for high quality yarns (e.g., combed ring spun yarns). The hollow profile has a maximum difference between the center of the element and the front side of, for example, 0.2 mm when cold, or in other words: the profile has been made 0.2 mm hollow. After the warm-up phase, the element is thermally stable or, in other words, in a stationary state of heat. Due to the various warm-up effects, this thermostabilization has led to the element again being shaped as a straight line. The hollow profile is designed over the working width so that the heat effect has been compensated, preferably in the production of high quality yarns.

Preferably, all rollers and work elements so hollow-shaped that they form a straight surface after the warm-up phase (when the steady heat state of the card is reached). In particular, the drum and associated working elements are most suitable for this inventive construction. On the drum, the narrowest settings on the card are selected. Due to the tight settings and the high circumferential speed of the drum (the highest on the card), the fiber / metal friction between the drum and working elements is highest there, which leads to the greatest heat development on the card. Thus, the distances of the elements to the card are influenced the most there. The smaller this distance, and the more precisely it can be adjusted and kept above the working width of the card, the higher the quality of the produced card sliver or end product (eg yarn).

Since elements such as rollers or working elements have different expansion shapes and thus different thermal expansions, the correction should be designed for an ideal production quantity, in particular the card can be designed overall for an ideal production quantity. In particular, the expansions to be expected should be taken into account in such a way that no collision between them is possible and that, in particular, no readjustment of the distance of the individual components from one another is necessary. A card according to the described invention has the individual elements formed so hollow that the correction of all elements has a uniform working gap result. However, the invention is not limited to the card as such, it can be used in particular for individual modules.

Figur 1

Schematische Seitenansicht eine Karde.

Figur 2A bis 2E

Schematische Darstellung der Wärmeeffekte und die erfinderischen Lösungsansätze, über die Arbeitsbreite der Karde.

With reference to the figures, the invention will be further explained. The same reference numerals are used for all drawings.

FIG. 1

Schematic side view of a card.

FIGS. 2A to 2E

Schematic representation of the heat effects and the inventive approaches, on the working width of the card.

FIG. 1 shows a Wanderdeckelkarde, z. Example, the Rieter card C60 with a working width of 1.5 meters, with a hopper 1. fiber flakes are transported through transport channels (not shown) through the various Putzereiprozessstufen and finally fed into the hopper of the card. This then passes the fiber flakes to the card as cotton wool. The feed roller 3 and feed trough 4 together feed the fiber flakes to the lickerins 5a, 5b and 5c. The lickerins open the fiber flakes and remove some of the dirt particles. The last licker-in roller 5c transfers the fibers to the card drum 6. The card drum 6 cooperates with the lids 7 and in this case further parallelizes the fibers. After the fibers have in part performed several revolutions on the card drum 6, they are removed from the take-off roller 8 of the card drum 6, fed to the squeegee 9 and finally deposited as a card sliver 10 in a can in a pot (not shown).

Stationary work elements can basically be assigned to each roller of the card. In particular, the licker-in elements 5a, 5b and 5c and the drum 6 are very often equipped with cleaning elements such as knives 18 or carding elements 17. The exact number of work elements and their sequence can vary from card to card. In principle, however, most rollers are completely covered so that no fibers, dirt and dust can escape. At the takeover point from roller to roller one finds rather guide elements, or a tongue. But even with the rollers in the hopper stationary working elements can be arranged, for example, disclosed EP 787841 Cleaning elements that are assigned to the dissolution point.

The drum 6 can be divided into four sub-areas. The pre-carding zone 12, the main carding zone 13, the post-carding zone 14 and the under-carding zone 15. In a revolving flat card, the revolving flats 11 form the main carding zone 13, while the pre-, post- and sub-carding zones are usually equipped with stationary working elements. However, there are also cards that do not have a revolving lid, instead there are stationary work items in the main carding zone. These stationary working elements may be cover elements or shuttering elements 16, carding elements 17, knives, possibly with a suction device 18, or guide elements 19.

FIGS. 2A to 2E illustrates the problem of thermal expansion and the inventive approaches schematically. As an example, a combination of a stationary working element 20 and a roller 21 was selected. However, the inventive solution can also be applied to other combinations such as two roller or a flat bar against a roller.

In FIG. 2A the working gap 22 is shown evenly over the entire working width. The stationary working condition is the desired situation. In order to avoid a collision between the two elements, this working gap is very often set somewhat further in practice with cold carding machines. After the card has reached its stationary heat state, the working gap is adjusted to the desired size.

FIG. 2B shows the situation after heating the card elements, wherein the surface of the elements by the thermal expansion cambered (or bulbous) are deformed. The largest expansion effects are in the middle of the working width, indicated by 23 in the drawing. As a result, the working gap has become considerably narrower here than in the peripheral areas. Figure 2C shows in addition to these heating effects, the temperature differences over the outside and center 24.

This may vary depending on the nature and location of the elements, both in the direction of the working width as shown in the roller or radially as shown in the working element. For example, with work elements such as flat bar or stationary work elements, this can lead to an overall curvature of the entire element.

An inventive approach is in FIG. 2D played. The working side is sufficiently hollow processed or directed, so that after the warming-up of the carding gap is again uniform over the entire working width. The mass of the hollow machining 25 corresponds to the expected thermal expansion in the desired production. Preferably, opposing elements are corrected so as to collectively achieve the desired working gap after thermal expansion without the need to adjust. Figure 2E shows a further inventive variant. In this variant, only one of the two elements is corrected, for example, in the drawing, the working element, while the opposite roller is not corrected. After the heat stabilization, a working gap is formed which is constant over the entire working width, although the shape of the gap itself is not straight, as described in US Pat FIG. 2A , This approach has the advantage that only a part of the card elements must be adapted.

The elements can either only be edited on the work surface or the element as a whole can be straightened. The processing can take place during the production of the element and / or in the post-processing. For example, turning, bending, milling or grinding are suitable as working methods. The correction is generally greater than the manufacturing tolerance, which is normally stopped in the production of card elements.

The inventive solution can be used regardless of the choice of material of the individual components.

Legend:

1. 1st hopper
2. 2nd resolution point
3. 3. food trough
4. 4. Feed roller
5. 5. a, b, c, licker-in
6. 6th drum
7. 7. Flat bar
8. 8. doffer roller
9. 9. squeegee
10. 10. Sliver
11. 11. Rotating lid device
12. 12. Vorkardierzone
13. 13. Main carding zone
14. 14. Post carding zone
15. 15. Unterkardierzone
16. 16. Covering or shuttering element
17. 17. carding segment
18. 18. Knife with possibly an extraction device
19. 19th guide element
20. 20. Work item
21. 21st roller
22. 22. carding nip or working nip
23. 23. thermal expansion
24. 24. Temperature gradient
25. 25. Correction
26. 26. Shape in cold condition
27. 27. Form after warm-up phase

Claims (6)

1. Element (7, 16, 17, 18, 19, 20, 21) for a card which, at least with one of its sides, can come into contact with the fibre material, characterized in that the element (7, 16, 17, 18, 19, 20, 21) at this side comprises a concave curve across the work width of the card, whereby the curvature of the curve of the element (7, 16, 17, 18, 19, 20, 21) is selected in such a way that the thermal deflection of the element is corrected.
2. Element according to claim 1, characterized in that this side has a carding function and/or a cleaning function and/or a doffing function and/or a covering function.
3. Element according to claim 1 or 2, characterized in that the element (7, 16, 17, 18, 19, 20, 21) is a work element (20), in particular a carding segment (17), a flat (7), a knife (18), a guide element (19), a cover segment (16) or a tongue (19).
4. Element according to claim 1 or 2 characterized in that the element (7, 16, 17, 18, 19, 20, 21) is a roller (21), in particular a drum (6), or a doffer roller (8).
5. Card with elements according to one of the claims 1 to 4, characterized in that the curvature of the curve of the element (7, 16, 17, 18, 19, 20, 21) is selected in such a way that only the thermal deflection of the element is corrected.
6. Card with elements according to one of the claims 1 to 4 characterized in that the curvature of the curve of the element (7,16,17, 18, 19, 20, 21) is selected in such a way that the thermal deflection of the element and of the counter element is corrected.

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