DE19527204C2 - Process for producing a ceramic spinning ring - Google Patents

Description

The invention relates to a method for manufacturing position of a ceramic spinning ring, the powdered ceramic starting material, preferably with small amounts of aggregates under high Pressure in a mold is pressed into a blank and the blank is then processed and sintered gene is subjected.

The spinning rings are known to be very subject high stress due to the friction of the rotor on the corresponding guide surfaces.

Your coefficients of friction must be kept low.

It is also the desire to have these low coefficients of friction crucial for the life of the ring traveler, under to maintain all operating conditions in the same way.

Have purely ceramic coatings on steel rings the disadvantage that the connection to the metallic support layer is not stable enough. The necessary sintering the ceramic layer requires very high temperature Ren. Steel and ceramic react when they cool down different.

At the junctures of both materials smallest cracks cannot be excluded.

Smallest cracks lead to loosening of the ceramic part chen. The first loosened particle solves a real one Chain reaction. The surface becomes rough. she is no longer suitable for guiding the runner.  

DE 43 42 148 A1 has already disclosed a spinning ring proposed that also entirely from ceramic plant fabric exists.

This spinning ring is closed in a manner known per se first pressed as a blank, then sintered and finally a final grinding process subjected. In this grinding process, which in itself, because of the great hardness of the ceramic material after the Sintering is already very troublesome surface of the ceramic material exposed crystals are very hard and sharp-edged.

The runner glides under the effect of acting on him the forces over these extremely hard and sharp edged Crystals, then the sliding surface of the runner is fast processed and the runner must be replaced.

To limit this adverse effect one has tried the tips of these crystals through one mechanical, chemical or thermal process in an additional operation and remove the rooms between the neighboring crystal tips through the fill in any abrasion.

Both measures have proven to be impossible exposed. The removal of the tips of the very hard Crystals did not succeed to the extent necessary.

The deposited abrasion between the crystal tips was not suitable for the runner to occur To carry loads over the tips.

The lifespan of being on such spinning rings The ring traveler remained under extreme stress considerably unsatisfactory.

The aim of the invention is to overcome the disadvantages mentioned remove.  

The object of the invention is to propose a method for producing a ceramic spinning ring which leads to a sliding surface for the ring traveler on the spinning ring,

• - which on the one hand is largely free of abrasive Crystal tips and
• - That the ring traveler a uniformly round Be pathway enables.

According to the invention, this object is achieved by the method solved, which is defined in claim 1.

Due to the mechanical processing of the blank not just the absolutely round circle that is necessary at first track created for the runner. On the surface of the A ceramic layer is exposed on the spinning ring is largely free of any additives.

The structure of the surface is exactly round and closed at this point in time homogeneous. It still consists of relative loosely bound ceramic crystals.

In the next step, sintering at temperatures around 2100 ° C, the surface of the crystals becomes one plastic state transferred. The bond between the Crystals are fixed and the surface tensions the loosened layer round off the spit Zen.

In the last step, the fine machining Loops, essentially single, are still high standing crystals knocked out of the composite. The resulting gaps in the surface do not influence the running behavior of the ring travelers.  

It is known from the literature (G. Spur, Kera mikverarbeitung, Carl Hanser Verlag Munich 1989, pages 44-46) Machined green compacts mechanically before sintering This processing takes place there, however The aim is to remove larger quantities of material and thus the Increase productivity.

In contrast to this, in the present proceedings the The goal is pursued, especially the runner life at the Increase application of ceramic spinning rings. Through the specific impact of green cultivation on The surface quality of the rings is this with the The method of claim 1 in a surprising way reached.

The completely made of ceramic material Spinning ring has sufficient hardness throughout and stability and is homogeneous in its structure and tension-free. Connection problems between layers made of different materials are excluded.

The sliding properties on its precisely machined The surface remains at different temperatures obtained in the same way.

Given these beneficial properties of Spinning ring according to the invention is the spinning ring for different fiber materials and also for extremely under different thread sizes can be used.

This also applies to the previously extremely critical one area "worsted" too.

The effort for the production of the ring is in Given its clear advantages in terms of Lifespan and area of application in a reasonable size north.

The method according to the invention is based on an off management example are explained in more detail. In the show associated drawings,

Fig. 1 shows a cross section through a spinning ring in cooperation with a rotor and a thread and

Fig. 2 is a schematic representation of an individual steps in the manufacture of the ceramic spinning ring.

The main dimensions of the spinning ring made of ceramic material shown in FIG. 1 correspond to the spinning rings customary for these fields of application. A detailed description does not have to be made here.

The cross-section of the spinning ring 1 is shown for the sake of marking the different functional surfaces 11 , 12 , 13 of the spinning ring 1 .

The surfaces on which the rotor 2 slides are referred to as guide surfaces 11 .

Particularly high demands are made on the surface quality of these guide surfaces 11 . These surfaces 11 are machined after pressing and subjected to a fine machining after sintering.

On the surfaces 12 , on the other hand, reduced requirements regarding the precision of the surface are provided. These surfaces 12 are machined after the blank 1 'has been pressed. You will not receive any subsequent processing after sintering.

The areas 13 are areas to which no special demands are made. You will receive no further processing after pressing. It is at the discretion of the manufacturer to cover these areas with special dimensional requirements or design forms.

The process shown schematically in FIG. 2 shows in section I the pressing of the spinning ring 1 as a blank 1 '.

The blank 1 'is pressed from a powdery, ceramic raw material in a rubber matrix under high pressure - here at least 2 kbar - using the so-called isostatic method in a rubber matrix 4 .

After a short time it stands for mechanical processing section II.

Here, all functionally important surfaces 11 and 12 are brought into the specified shape (1 ") by mechanical processing with hard metal tools 5 .

In the third processing stage - section III - the spinning rings 1 "are lined up on holding devices and sintered in a closed space 6 under protective gas at 2100 ° C. with the usual time sequences.

In a last step - section IV - the sintered spinning rings 1 are ground in the area of the guide surfaces 11 with the aid of diamond tools 7 and are then available for use on the ring spinning machine.

The choice of ceramic material is basically free, based on the production of the spinning ring. In view of the high demands on the sliding properties and the temperature resistance, it has proven to be expedient to use zirconium oxide ZrO ₂ (Z-700).

The tests carried out confirm the expectations in a convincing way.

These spinning rings make very good sliding doughs runners achieved. You are independent on temperature, speed and independent depending on the type of fiber material used.

The spinning ring does not need to be lubricated. This also applies to the processing of long-stacked ones Fibers and wool too.

The spinning ring also allows the use of Flanschlufen, which are necessary for the wool area.

Soiling of cops is prevented.

Claims (1)

1. A process for producing a spinning ring from Kera mik, wherein the powdered ceramic starting material al. is preferably pressed with a small amount of additives under high pressure in a mold into a blank and the blank is then subjected to processing and sintering processes, characterized in that
that in the first operation the blank ( 1 ') made of the powdery material is pressed isostatically at about 2000 bar in a rubber die ( 4 ),
that in a second operation the blank ( 1 ') is machined with tools ( 5 ) in a manner known per se,
that in the third step the machined spinning ring is sintered at temperatures up to 2100 ° C and
that in the last step at least the guide sliding surfaces for the rotor are subjected to a fine machining by grinding with diamond tools ( 7 ).