EP1068382A1

EP1068382A1 - Ring for ring frames and ring twisters

Info

Publication number: EP1068382A1
Application number: EP98909264A
Authority: EP
Inventors: Jörg KÄGI
Original assignee: Braecker AG
Current assignee: Braecker AG
Priority date: 1998-04-02
Filing date: 1998-04-02
Publication date: 2001-01-17
Anticipated expiration: 2018-04-02
Also published as: ATE219795T1; ES2175684T3; DE59804610D1; TR200002870T2; US6360521B1; CN1295634A; PT1068382E; CN1190536C; EP1068382B1; JP2002510755A; WO1999051802A1

Abstract

A ring for a ring spinning or a ring twisting machine, comprising an annular polished core and a hard chrome layer, wherein the core is coated with a copper layer, and wherein the hard chrome layer is applied to the copper layer.

Description

Ring for ring spinning and ring twisting machines

The invention relates to a ring for ring spinning and ring twisting machines.

In addition to a precisely machined shape, a ring for a ring spinning or ring twisting machine must have an optimized surface that is adapted to the requirements in order to enable a ring traveler that rotates on the ring at speeds of up to 55 m / s to run smoothly and with as little wear as possible . For this, the surface of the ring must be as smooth and hard as possible and may only oppose the ring traveler with a low running resistance. The ring should be low-wear, since with increasing wear of the ring, the smooth running of the ring traveler on the ring is impaired, which can lead to increased thread breaks. In addition, with increasing wear defects of the ring, the wear of the ring traveler also increases, which leads to shorter service lives of the ring traveler and ring, which in turn, like the increased thread breaks, increases the production costs.

The object of the present invention is therefore to create a ring for ring spinning and ring twisting machines, which enables rings and ring travelers to be used more economically.

This object is achieved by a ring which has the features of claim 1.

A hard chrome layer, which is preferably applied directly to a core of the ring, gives the ring a very hard, wear-resistant surface that adheres firmly to the core of the ring. Hardness values of the hard chrome layer measured according to Vickers HV 0.05 from 900 to 1300, preferably with values above 1000, are advantageous. Surprisingly, the hard chrome layer can be problem-free be used as a coating for the ring, although very high temperatures (up to approx. 1000 ° C) can occur on the rings during the rapid rotation of the ring travelers. A person skilled in the art knows (cf. Schatt: "Materials of machine, plant and apparatus construction", VEB German Publishing House for Basic Industry, Leipzig 1982, p. 144) that hard chrome layers soften at temperatures above 400 ° C, which is why the use of hard chrome - coatings for rings have never been considered.

The core of the ring advantageously has a core surface which has been polished before the hard chrome layer is applied. The core can also be coated with a copper or nickel layer, which in turn is then polished and on which the hard chrome layer is arranged. Such nickel or copper layers on the core and under the hard chrome layer are particularly advantageous under corrosive operating conditions of the ring. A hard chrome layer applied to a polished core surface has a very smooth surface, which causes a ring rotor to run very smoothly on the hard chrome-plated ring. Commissioning without ring run-in is therefore possible without any problems, which greatly reduces the loss of production due to run-in times.

A ring whose hard chrome layer applied to the core of the ring also has a polished surface offers particular advantages, since the polishing of the surface of the hard chrome layer rounds off sharp-edged tips of chrome crystals that can protrude from the surface of the hard chrome layer. These pointed, sharp-edged crystals of the hard chrome layer have a file-like effect and cause excessive wear on objects sliding or sliding over the hard chrome layer. These file-like properties of the previously known hard chrome layers are another reason why Hard chrome layers have never been considered for rings for ring spinning or ring twisting machines. However, if the hard crystal tips of the hard chrome layer are rounded off by polishing, this problem is eliminated. The ring only has a low running resistance against the ring traveler rotating on it and there is no increased wear on the ring traveler. Thus, if the core surface and the surface of the hard chrome layer are polished, a very smooth, hard and wear-resistant ring surface is obtained, on which the ring traveler can rotate with little wear. The roughness of the core surface before the hard chrome layer is applied is, for example, Ra 0-0.3 μm, preferably less than 0.2 μm. At a value Ra of the core surface of 0.15 μm, for example, the surface of the hard chrome layer applied thereon also shows a roughness of approximately 0.15 μm.

If structured hard chrome layers (so-called topocrom layers) and / or chrome dispersion layers in which non-metallic components are enriched (ECD layers) are used, the properties of the hard chrome layer can be varied and precisely adapted to the respective requirements.

It is also advantageous if the core of the ring is made of tempered steel. Large centrifugal forces can arise from the high speeds at which the ring rotors rotate on the rings, so that the ring rotors

Apply pressure to the ring.

Thread breaks at these rotational speeds can lead to a sudden impact load on the ring

Lead ring traveler. Too soft a base material of the core leads to Ungen in such pressure or shock Bela ^~

Damage to the core and hard chrome layer. Is this

The base material of the ring, on the other hand, is a tempered steel, so the material underneath the hard chrome layer does not yield, even under high pressure and sudden impact loads, and the ring can withstand these loads without it Survive damage to the hard chrome layer and the underlying core. This is possible because the hard chrome layer is applied at temperatures below 100 ° C and the properties, such as hardness, of the base material are no longer changed, for example, by recrystallization or heat diffusion processes. The lifespan of the ring is increased, and even after an event, such as a thread break, the ring traveler can continue to run smoothly on the ring with little wear. Tempered roller bearing steel has proven to be particularly suitable for use as the core of a ring.

Rings that have a core with a nickel or

Having copper layer, which is arranged under the hard chrome layer, show eir.e particularly good

Corrosion resistance, making them suitable for use in extreme conditions such as wet spinning are particularly suitable.

The hard chrome layer advantageously has a thickness between 1 .mu.m and 60 .mu.m, the layer thickness in a preferred embodiment being the thickest in the area of the highest stress, that is to say in those areas of the ring which come into contact with the ring traveler during its movement on the ring is.

A ring that has the hard chrome layer only in the areas that form contact surfaces between the ring and ring traveler when the ring traveler runs on the ring, as well as a ring completely coated with a hard chrome layer leads to better running properties of the ring traveler on the ring and thus to a longer service life , fewer thread breaks and less wear on the ring itself, which means that even with such a ring, the ring and ring traveler can be used more economically. The ring has at least one electrical contact point, via which the ring is supplied with current during the application of the hard chrome layer. This electrical contact point is advantageously located in the area of a seat, which lies opposite the area having the contact surfaces, for example a flange. This arrangement ensures that there are no undesirable unevenness, roughness or other disturbances in the area of the contact surfaces due to the electrical contact points in the hard chrome layer or on the surface of the ring. Even if the location of the electrical contact points can no longer be located by the eye after the hard chrome layer has been polished, the hard chrome layer can nevertheless have micro-faults at these locations, which have a negative influence on the wear resistance or running of the ring traveler or the wear resistance of the ring.

A hard chromium-plated ring according to the invention can advantageously be used in all spinning and twisting mills that work with ring spinning or ring twisting machines, since the production costs can be reduced by using such a ring. The ring offers special advantages wherever materials are processed that release lubricating substances, such as animal fat or fibers with lubricating properties, in the area of the ring and the ring traveler. The ring is particularly suitable for processing cotton with its short, lubricating fibers. Since the surface of the ring has a very high wear resistance and only offers a low running resistance to the ring traveler, so that it runs on such a ring with very little wear, no additional lubrication, such as with molybdenum disulfide lubricant, is required to ensure long service life and continuous work to ensure with few thread breaks. Even for conditions as extreme as they are occur when wet spinning, the ring is very suitable. Good corrosion resistance, as is particularly important under these conditions, is achieved with a ring rotor, the hard chrome layer of which is pre-nickel-plated or copper-coated, for example.

Further preferred embodiments and uses are the subject of further dependent claims.

The invention is explained below by way of example with reference to FIGS. 1 to 3. It shows purely schematically:

1 shows a part of a ring with a T

Flange and with a ring traveler running around it;

Fig. 2a to 2c rings with different flange profiles in cross section with matching ring travelers

3b shows the ring from FIG. 2a with the core surface only partially coated; and

3b shows the ring from FIG. 2a with a completely coated core and indicated layer thickness distribution of the hard chrome layer on this core.

1 shows, in perspective, part of a ring 10 coated with a hard chrome layer 26 (not explicitly shown) with a core 11 made, for example, from tempered roller bearing steel, one side of which is designed as a T-flange 12. The side opposite the flange 12 is designed as a seat 18, wherein the seat 18 can be designed in a wide variety of ways, for example also as shown in FIG. 2c. The annular core 11 of the ring 10 has a polished core surface 28. In the area of the seat 18 there is an electrical contact point 19 (indicated by dashed lines in FIG. 1), via which the ring is supplied with current during the electrochemical application of the hard chrome layer. Before the chromium is deposited on the ring 10, the core 11 of the ring 10, which has a core surface 28, can either be coated with another layer, for example a nickel or copper layer, or it can, as in this example, be anodically etched so that all oxides, impurities or, for example, also intermediate preservatives or the like are removed from the core surface 28 and the hard chrome layer 26 can be deposited directly on the core surface 28.

On the T-flange 12 of the hard-chromed ring 10 shown in FIG. 1, a suitable C-shaped ring traveler 14 runs in the direction of arrow I. Due to the centrifugal force acting on the ring traveler 14 during the rotation (arrow F), the ring traveler becomes 14 on the ring 10 in the radial direction with respect to the ring 10 pressed outwards. An invisible flank of the C-shaped ring traveler 14 hangs on the radially inner side 16 of the flange 12 of the ring 10 and thus holds the ring traveler 14 on the ring 10.

2a and 2b each show a sectional view of two embodiment forms of hard chrome-plated rings 10 with T flanges 12 and with matching C-shaped ring travelers 14 which are also designed somewhat differently. 2c, on the other hand, shows the section of a hard chrome-plated ring 10, the core 11 of which is designed in the form of an oblique flange 17. Also formed from the core 11, a seat 18, which in this example has a square cross section, is arranged opposite the inclined flange 17. A matching hook-shaped ring traveler 19 is shown on the inclined flange 1 ^″ . All ring travelers 14, 19 are shown in a position with respect to the respective flange 12, 17 that they are during of the company in relation to the ring 10. A respective flank 20, 22 of the ring traveler 14, 19 lying radially inward with respect to the ring 10 bears against the radially inner side 16, 16 'of the respective flange 12, 17, so that there is between the ring traveler 14, 19 and the flange 12 , 17 of the respective ring 10 forms a contact surface 24. In the area of this contact surface 24, the stress on the ring 10 with regard to wear, temperature, pressure, etc. is greatest. In order to counter this load accordingly, a hard chrome layer 26 is thickest in this area of the ring 10.

3a and 3b, the ring from FIG. 2a is shown again in section. The hard chrome layer 26 only covers part of the core surface 28 in FIG. 3a, while the core 11 of the ring 10 shown in FIG. 3b is completely covered with the hard chrome layer 26. The hard chrome layer 26 is applied directly to the polished core surface 28 of the core 11 of the respective ring 10. Because a fader. 30, which is guided through the ring traveler 14, 19 during operation (indicated by dashed lines in FIG. 1) and is under different tension depending on the speed, type of thread and machine settings, the area of the ring 10 or its flange 12, 17 which forms the contact surface 24 with the ring traveler 14, 19 vary locally. A region A on the radially inner side 16 of the flange 12 of the ring 10, on which the contact surface 24 can form during operation, is therefore chosen to be somewhat larger than the contact surface 24 actually formed at this point.

Since this area A, in which the contact surface 24 will be formed during operation, is exposed to the highest loads, the hard chrome layer 26 either becomes more or less thickest only in this area A (see FIG. 3a) or in this area A. (see Fig. 3b) applied. - 9 ^-

3a shows an embodiment in which the hard chrome layer 26 is applied primarily in area A and a little in a transition area B, which can also be loaded (see below). The remaining area C of the ring 10 is not coated with the hard chrome layer 26. Such a ring 10 has the same advantages, less wear of ring 10 and ring traveler 14, 19, high running smoothness, few thread breaks, etc., as a completely chrome-plated ring 10.

In the fully coated embodiment shown in Fig. 3b, the thickness of the hard chrome layer 26 in area A is e.g. 20-40 µm. In a transition region B on the radially inner side 16 of the flange 12, the hard chrome layer 26 has an average thickness of 10 to 25 μm. The layer thickness in the remaining area C, which makes up the remaining part of the ring 10, is at least 4 μm. The reason for the average layer thickness of the hard chrome layer 26 in the transition area B of the ring 10 is that during operation with an unfavorable parameter setting (thread type, thread thickness, ring traveler shape, ring traveler weight etc.) there is also a contact surface 24 between ring traveler 14 in this transition area B. 19 and ring 10 can form. So that the ring 10 does not immediately show damage after a single operation with such an unsuitable parameter setting and can continue to be used without any problems, it is useful for the ring 10 to have a somewhat thicker hard chrome layer 26 in this area B than in the remaining area C.

In order to ensure that the ring traveler 14, 19 runs smoothly and, above all, with little wear, on the ring 10, the surface 32 of the hard chrome layer 26 is polished in both examples, at least in area A, for example to Ra 0.2 μm. So that the core 11 of the ring 10 is just as resistant as the hard chrome layer 26 applied to it, the core 11 is, for example, a roller bearing steel with a tempered surface. Impact or pressure loads can thus be absorbed by the ring 10 without the hard chrome layer 26 being damaged due to the yielding of an underlying core 11 made of relatively "soft" material. However, other materials, such as other case-hardened, tempered and non-tempered steels, ceramics, plastics or, for example, composite materials, which have comparable properties, such as hardness, impact resistance, etc., are also conceivable as the base material for core 11, such as tempered roller bearing steel. The core can be coated with a nickel or copper layer for better corrosion resistance. The hard chrome layer itself can also be an ECD or a topocrom layer.

As the different shapes of the rings 10 shown in FIGS. 2a to 2c have already indicated, all ring shapes are suitable for being formed as a ring 10 with a hard chrome layer 26. Also with regard to the material and the shape of the ring traveler 14, 19 there are no restrictions with regard to their usability together with the ring 10 according to the invention.

Claims

WO 99/51802 _] _] _ _ PCT / CH98 / 00124 patent claims

1. Ring for a ring spinning or ring twisting machine, characterized by an annular core (11) which has a hard chrome coating (26).

2. Ring according to claim 1, characterized in that the hard chrome layer (26) of this hard chrome coating has a polished surface and is preferably a hard chrome layer structured in itself and / or enriched with non-metallic components.

3. Ring according to claim 1 or 2, characterized in that the hard chrome layer (26) directly on the core

(11) of the ring (10) is applied and the core (11) located under the hard chrome layer (26) has a particularly polished core surface (28).

4. Ring according to claim 1 or 2, characterized in that the core (11) is coated with a copper or nickel layer and this copper or nickel layer has a particularly polished surface.

5. Ring according to one of the preceding claims, characterized in that the core (11) of the ring

(10) is made of steel, in particular from a tempered steel.

6. Ring according to one of the preceding claims, characterized in that the hard chrome layer (26) is between 1 m and 60 µm thick, has a hardness HV between 900 and 1200 and a roughness Ra of in particular up to 0.3 µm.

7. Ring according to one of the preceding claims, characterized in that it has a contact surface (24), which by the running of a ring traveler (14, 19) on the ring (10) resulting contact points is determined, and that at least the contact surface (24) has a hard chrome layer (26), whereby, if further surfaces have a hard chrome layer (26), the hard chrome layer (26) of the contact surfaces is thickest.

8. Ring according to claim 7, characterized in that the ring (10) on one of the side with the contact surface (24), which is preferably designed as a flange (12), opposite seat (18) has an electrical contact point (19).

9. Use of the ring (10) according to any one of claims 1 to 8 for processing fibrous materials that emit substances with lubricating properties, in particular lubricating fibers, such as cotton.

10. Use of the ring (10) according to one of claims 1 to 8 in a spinning or twisting mill.