DE3110993A1 - Laminated core for inductive components - Google Patents

Abstract

The invention relates to a laminated core, which is closed without an air gap, for inductive components, which laminated core is constructed from laminate blanks which are geometrically identical in the plane of lamination and consist of materials having different electrical and/or magnetic properties. In consequence, the physical characteristics, for example the magnetisation curve, the temperature dependency, the permeability or the eddy-current formation of the laminated cores can be influenced. Laminated cores of such construction are preferably used in inductive movement sensors for linearising the transmission characteristic and for reducing the temperature influence. <IMAGE>

Description

Layer core for inductive components

The invention relates to a layered core that is closed without air gaps for inductive components, such cores are layered from so-called sheet metal components; they are geometrically the same z, B. frame-shaped stamped parts from a ferromagnetic Material. The coil windings are placed on the finished core in a known manner upset.

From the electrical and / or magnetic properties of the layer core The essential operating parameters of the inductive component depend on the determining ones Characteristic curves are e.g. magnetization characteristic, hysteresis loop, temperature dependence the permeability, control characteristic for transducers and transmission characteristic especially with inductive position or angle encoders.

Such operating parameters can be influenced via the properties the ferromagnetic material used for the core, the core cross-section and the shaping of the sheet metal cuts take place, as is known, for example, from DE-OS 2352851 is.

In the series production of inductive components, especially small ones Series, but this requires the costly provision of various punching tools, Mounting devices and housings.

It is therefore the task of closed air-gap-free To create layer cores in which without changing the geometric dimensions of the core it is possible to influence the operating parameters.

According to the invention, the object is achieved in that the layer core from sheet metal sections that are geometrically the same in the layer plane and made of materials with different electrical and / or magnetic properties.

The sheet metal cuts are of different thickness, from different alloyed or made of differently pretreated materials with the same stamping tools and devices can be produced.

For example, the magnetization curve of a layer core can be created by using of non-annealed sheet metal sections that have been subjected to an annealing treatment same starting material can be varied.

The temperature dependence of the magnetization curve can also be in one be kept at least approximately constant over a wide range.

Layer cores constructed according to the invention are preferably used with inductive displacement encoders based on the transformer principle with displacement-dependent displacement elements influencing induction to linearize the transfer characteristic, especially in the beginning and end areas or to adapt to a given one Function.

To explain the invention, FIGS. 1 and 2 show exemplary embodiments shown by layer cores different and / or the same cross-section. In figure 3 is a displacement encoder as an application example and in FIG. 4 is the displacement voltage diagram the posed.

In Figure 1 is a cross section through the leg of a frame layer core shown as it is used, for example, in an inductive displacement encoder according to Figure 3. It is made of core sheets B1, B2, B3, etc., layered, which are the same in the layer plane geometric shape, but have different thicknesses d1, d22 d3. You can in repeating order R1. . . R be layered and made of the same ferromagnetic tables material.

With this arrangement, the eddy current formation in the core and thus the attenuation of the electromagnetic system can be influenced.

Further possibilities of the layer core structure are that, as shown in the core leg cross-section according to FIG. 2, sheet metal sections Be B same shape, but made of materials with different magnetic properties be used.

The individual sheet metal cuts B4 B can, for example, consist of n so-called Electrical steel sheet, made of soft magnetic alloys with varying amounts of nickel and / or made of materials pretreated in annealing processes.

There are also mixed forms, i.e. layered cores with sheet metal cuts of different types Thickness according to Figure 1 and different electrical or magnetic properties possible, The magnetic properties and thus the structure of a layer core for a specific application, the known magnetization curves Approximately calculate commercially available ferromagnetic materials and empirically fine vote, in Figure 3 is an example of an application constructed according to the invention Layer core shows an inductive displacement transducer with an air gap-free closed one Frame core 1 of rectangular Form layered from sheet metal cuts is, iri the representation parallel to the plane of the drawing.

The feeding primary winding is on its short legs 2 2 ' w and the secondary winding consisting of two partial windings w51 and w52 bep Decrease in the measurement signal arranged on one of the long legs 3 of the frame core 1, a short-circuit winding 4 is mounted displaceably over the path s.

It produces the effect of a fictitious air gap, so that the secondary windings wsl and w52 connected in difference to the position of the Short-circuit winding 4 and thus the measurement signal UA mapping the path s can be decreased.

If the frame core 1 is made of both material and how the same sheet metal steps are built in terms of shape, so is its transfer characteristic, the curve I in the diagram of Figure 4, only in its middle area between the Puffits S1 and 52 linear, in the end areas it is non-linear, so that the full The length of the leg 3 cannot be used for the distance measurement, because the permeability ferromagnetic materials is more or less temperature-dependent, changes the transfer characteristic with temperature.

Cf. curve I at 200 ° C. and curve II at 700 ° C. in FIG. 4. The linear middle range s3. . . S4 is further reduced at higher temperatures.

Due to the mixed structure of the core 1 from sheet metal parts with different Magnetization curves and various temperature dependencies can be used both Improve the linearity of the transfer characteristic, as well as the temperature dependency considerably, as the comparison of curves III and IV shows. The way s will in the area s5. . . s6, i.e. almost the full free length of the leg 3 mapped linearly in MeB signal UA.

Claims 4 figures

Claims (5)

Claims 1. Air gap-free closed layer core for inductive Structural elements that do not exist in the layer level geometrically identical sheet metal cuts B1. . . B n made of materials with different electrical and / or magnetic: chen properties is built up. 2. Air gap-free, closed layer core for inductive components, d a d u r c h e k e n n n z e i c h n e t that it is geometrically made in the layer plane the same sheet metal centers B1 of different thicknesses (d1... d3) is constructed 3. Layered core according to Claim 1 or 2, because it is indicated that the sheet metal sections are made from different alloyed materials. 4. Layer core according to claim 1, 2 or 3 d a d u r c h g e -k e n It is noted that the sheet metal cuts are made from differently pretreated materials are made. 5. Layer core according to claim 1 or 2 d a d u r c h g e k e n n -z e i c h n e t that the sheet metal cuts in a repeating sequence (R1.. R) are layered. 6, layered cores according to one or more of the preceding claims g e k e n n n z e i c h n e t d u r c h its use in inductive displacement encoders with movable elements (4) to influence the functional dependence of their electrical output variable (UA) of the one way (s) mapping position of the movable Elements (4).