PROCEDURE AND MECHANISM FOR THE DETERMINATION OF THE YIELD POINT OF A SUBSTANCE

The invention concerns a procedure and a mechanism for the determination of the Fließ border a substance, for example from a fat or a thickened liquid, gemäß the generic terms of the requirements 1 and 3.

From the USA 4,164,212 a mechanism is for the determination of the Fließ border a body fluid well-known, which serves to determine the Menstruationszyklus. The well-known mechanism points a spherical Meß body up, that tiltable in a complementary Meß chamber in-lies and of a staff is away. The Meß body is moistened with the body fluid, into the Meß chamber assigned and the staff by plant at an attack of the Meß chamber being located in a firmly given angle diagonally upward aligned. Dependent on the Fließ border the body fluid remains the staff in his position or it by his Gewichtskraft downward one swivels. With the well-known mechanism läß t only determine themselves whether the Fließ border the body fluid a firmly given value exceeds or falls below.

From the USA 2,747,399 a mechanism is for the determination of the Fließ border from grease well-known, with some plattenförmiger Meß body is immersed into a container containing the grease. The Meß body is attached at a side of a scale beam of a beam balance. On the other side of the scale beam a pan hangs, on the Meß weights are presentable. The mass of the presented Meß weights, those the Meß body from the grease pulls out, is a Maß for the Fließ border the grease.

The invention is the basis the task, a procedure for the determination of the Fließ border to indicate, with that the Fließ border simply and with high accuracy to be determined can.

One receives the solution of this task by the characteristics indicated in the requirement 1. In the substance, their Fließ border to be determined is, immersing Meß body slowly from a vertical quiescent position into increasingly more strongly bent positions is brought, until it reached a boundary position, in which it due to its dead weight still continues to bend. The boundary position is held and serves for the determination of the Fließ border the substance.

With that erfindungsgemäß EN procedure is used the fact, daß for example a staff in a fat or a structured substance also with an angle of inclination arbitrarily for a long time without automatic to fall down be located remains, as long as the boundary position specified above is not yet reached. Only with reaching the structuralspecific boundary position the staff falls down due to its dead weight. With that erfindungsgemäß EN Meß proceeded can as Meß bodies round bar or another elongated article with suitable profile to be used, that at its Fuß point is as frictionlessly as possible tiltable stored. For this purpose the staff at its Fu&szlig can; point a cut or a point exhibits, with which it at the ground of a Meß chamber, which takes up the substance, is tiltable stored.

The Meß body can be brought up to the boundary position by slow, continuous swivelling or by a gradual swivelling in small angle angles. Can within the range of the Fließ border for the improvement of the Meß dissolution the Schwenkgeschwindigkeit to be reduced and/or the angle steps in smaller and in temporally größ eren distances to be made.

The angle of inclination of the Meß body in the boundary position opposite the vertical one makes possible in connection with the weight of the Meß body and its profile a standardized indication for the Fließ border the substance. Muß to be if necessary also considered whether and how far the Meß body from the substance with its upper end stands out. The computational consideration of these Meß gave for the determination of a standardized Fließ do not border is the subject of this invention, since in principle also the possibility would exist, for all measurements always uniform Meß body under same other Meß to use conditions, so daß alone the angle of inclination in the boundary position a indirect Maß for the Fließ border would indicate.

The invention is the basis further the task to create a mechanism with that the Fließ border a substance with simple means and as gro&szlig as possible; it accuracy to be determined can.

One receives the solution of this task by the characteristics indicated in the requirement 3. The substance is in a Meß chamber, into some Meß body dives in, which is swivelled slowly and/or gradually by a slewing mechanism from the vertical situation into a bent situation. As soon as the Meß body of the slewing mechanism automatically stands out is reached the boundary position, those as Maß for the Fließ border the substance serves. From the angle of inclination of the slewing mechanism or the Meß body in the boundary position can with consideration of further Meß parameter the Fließ border the substance to be determined. The Meß structure is very simple and can for different substances in an appropriate way by very simple Maß took angepaß t become. So for example very low Flie&szlig can for a substance with; border a particularly easy-weighty Meß body to be used, for example a thin-walled pipe.

The slewing mechanism is preferably operated by a stepping motor via a transmission. A control can change the temporal sequence of the individual drive steps so, daß straight within the range of the Fließ border the boundary position to be very accurately determined can. Preferably taking the Me&szlig off becomes; body of the slewing mechanism of an optical or electrical sensor determined and the control communicated, so that this can record the associated angle position automatically. The entire Meß procedure can run off thereby automatically.

The Meß chamber preferably possesses a V-shaped profile, thereby as small a quantity of the substance for the Me&szlig as possible; procedure is sufficient. Also different Me&szlig can do; chamber-form to be used, those auß erdem at liquids with higher or low Fließ border in the form angepaß t to be can.

At a Me&szlig trained as a staff; body can be additionally a replaceable weight attached, around the weight of the Meß to be able to vary body in a simple manner.

A rod-shaped Meß body can at its Fuß point a point or a cut exhibits, those the articulated bearing for the Meß body forms.

The invention is more near described in the following on the basis a remark example represented in the design.

Show:

1. Figure 1 the process of a Fließ circle,
2. Figure 2 the principle of the mechanism for the determination of the Fließ border,
3. Figure 3 the structure in principle of the mechanism for the determination of the Fließ border and
4. Figure 4 the profile of the mechanism of figure 3 within the range of a sensor attached at the slewing mechanism.

In figure 1 is as Fließ circle the shear stress τ as a function of the Schergefälle D represented. The Fließ border F lies, where the shear stress straight so groß is daß itself with the substance, their Fließ border to be determined is, in contact of bodies present in motion sets.

Figure 2 shows the Me&szlig represented in figure 3; chamber 1 in the profile, in whose V-shaped transmitting room 2 a substance 3 is. As elongated round bar of trained Meß body 4 dips 3 up to the ground 5 the Me&szlig into the substance; chamber 1. The Meß body 4 has at its Fuß point 6 a point 7, the one practically frictionless swivelling of the Meß body makes 4 in direction of arrow 8 possible.

The Meß body 4 is opposite the vertical one 9 around an angle of inclination α expenditure-guided, which is still so small however, daß the Meß body 4 in the represented position is held by the substance. The angle α is thus so small, daß the Meß body 4 yet due to its dead weight in direction of arrow 8 does not fall down.

Over now the Fließ border the substance to determine to be able, the Me&szlig becomes; body 4 very slowly and if necessary in small angle angles in direction of arrow 8 so for a long time moved, until the boundary position is reached, in that the dead weight of the Meß body 4 is sufficient, in order to further-swivel it automatically in direction of arrow 8. Depending upon condition of the substance and according to high or low Fließ border can the boundary position 10 with according to different angles of inclination lie. With consideration of the profile, the dead weight and the determined boundary position 10 a value for the Flie&szlig can; border the substance to be indicated. The Flie&szlig can; border in the Maß unit N/m2 (Newton per square meter) or also in another Maß unit to be indicated.

Figure 3 shows a mechanism with a Meß chamber 1, with that the Meß body 4 by means of a slewing mechanism is swivelled 11 from its rest position with increasing angle of inclination. In the Meß chamber 1 is, as already with figure 2 mentioned, the substance 3, their Fließ border to be determined is. At 4 Me&szlig diving in into the substance; body fits on one side a transverse bar 12 of the slewing mechanism. This transverse bar contains a wedge-shaped cutout 20, in that the Meß body lies close and is led. The transverse bar 12 is swivelled by a stepping motor 13 in direction of arrow 8 in small angle angles, to the Meß body 4 automatically of the tie bar 12 due to its dead weight stands out. Within the range of the transverse bar a sensor 14 arranged taking the Me&szlig off recognizes 12; body and this announces 4 of the transverse bar 12 to a control 15, so that this can record the angle of inclination with the reached boundary position. The control 15 steers the stepping motor 13 during the entire Meß procedure, so daß in the control 15 constantly the current angle of inclination of the Meß of body 4 admits is. The current angle of inclination can be held for example in a memory, so daß with reaching the boundary position the current memory value for the determination of the Fließ border angle of inclination which can be consulted exhibits.

In figure 4 is a Meß body 4 with a weight 16 replaceable appropriate at its shank represented.

Further the cross section of the transverse bar 12 and the sensor 14 are evident. As sensor in principle different sensor elements can be used, for example optical, inductive or capacitive sensor elements.

The point 7 of the Meß body forms 4 in connection with the ground 5 (figure 2) a practically frictionless articulated bearing 17. In place of the point 7 represented here also cut or another suitable camp element use can find.