CORE BODY OF FERROMAGNETIC MATERIAL, MAGNETIC CORE FOR AN INDUCTIVE COMPONENT AND METHOD OF FORMING A MAGNETIC CORE

• US 20150270051A1
• Filed: 03/16/2015
• Published: 09/24/2015
• Est. Priority Date: 03/19/2014
• Status: Active Grant

• Current Assignee: Sumida Components & Modules GmbH (Sumida Corporation)
• Original Assignee: Sumida Components & Modules GmbH (Sumida Corporation)
• Inventors: GRUBL, Martin, ROTT, Helmut
• Granted Patent: US 9,620,277 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01F 27/24 Magnetic cores
• CPC Class Codes: H01F 27/255 made from particles H01F27/26 takes precedence
• CPC Class Codes: H01F 27/263 Fastening parts of the core together
• CPC Class Codes: H01F 41/0246 Manufacturing of magnetic circuits by moulding or by pressing powder magnetic cores made by moulding or by pressing powder H01F27/255; soft magnetic particles H01F1/20, H01F1/36
• CPC Class Codes: H01F 7/06 Electromagnets; Actuators including electromagnets electric coils H01F5/00; devices for holding workpieces using electric force B23Q3/15; load-engaging elements for lifting articles electromagnetically B66C1/06; electromagnetic couplings F16D27/00; magnetic brakes F16D63/002; electromagnetically operated valves F16K11/24, F16K31/00; analysing materials by magnetic means G01N27/72, G01N27/80; electromagnets for winding mechanical clocks G04C1/02; electromagnetic relays H01H51/00; windings for salient poles of dynamo-electric machines H02K3/18; electromagnets for telegraphic communication H04L; for arc lamps H05B31/28
• CPC Class Codes: Y10T 29/49075 including permanent magnet or core

Abstract

Core bodies which have an alignment structure and allow an alignment during the production of magnetic cores irrespective of production tolerances, in which the production tolerances are compensated. In illustrative embodiments a core body of ferromagnetic material comprises a crossbar having an aspect ratio of length to width greater than 1, and at least one core leg extending laterally away from the crossbar along an extension direction. An alignment recess is formed in a rear surface of the crossbar, which is arranged on a side of the crossbar opposite the core legs. A magnetic core is formed of core bodies, whereby at least one core body is provided with an alignment recess, and the core bodies are aligned relative to one another.

Claims

1. Core body of a ferromagnetic material, comprising:

a crossbar having a length dimension and a width dimension, wherein a ratio of length dimension to width dimension is greater than 1;

at least one core leg which extends laterally away from the crossbar along an extension direction, wherein the extension direction is oriented perpendicular to the length dimension and the width dimension; and

an alignment recess which is formed in a rear surface of the crossbar, which is arranged on a side of the crossbar opposite the core legs.

2. Core body according to claim 1, wherein the alignment recess is arranged at the centroid of the rear surface.

3. Core body according to claim 1, wherein the core body furthermore comprises at least a second core leg, and the alignment recess is arranged, in the rear surface, centered relative to two core legs, the two core legs being arranged eccentrically with respect to the length dimension.

4. Core body according to claim 1, wherein the at least one core leg is arranged centrally on the crossbar, perpendicular to the extension direction, and the alignment recess is arranged to be face-centered with respect to a cross-sectional area of the at least one core leg oriented perpendicular to the extension direction.

5. Core body according to claim 1, wherein the alignment recess has an alignment surface which is formed at least according to a partial area of a hemisphere surface or a conical surface.

6. Core body according to claim 1, wherein the alignment recess includes at least three planar alignment surfaces.

7. Core body according to claim 1, wherein a width dimension of the alignment recess is less than 50% of the width dimension of the crossbar, and a length dimension of the alignment recess is less than 50% of the length dimension of the crossbar.

8. Core body according to claim 1, wherein a depth extension of the alignment recess into the core body is less than 50% of a height dimension of the crossbar, which is oriented parallel to the extension direction.

9. Core body according to claim 1, wherein the core body is formed of a sintered ferrite material.

10. Magnetic core for an inductive component, comprising:

a first core body of a ferromagnetic material which comprises a first crossbar having a length dimension and a width dimension, wherein a ratio of length dimension to width dimension is greater than 1, at least one first core leg which extends laterally away from the first crossbar along a first extension direction, wherein the first extension direction is oriented perpendicular to the length dimension and the width dimension, and an alignment recess which is formed in a rear surface of the first crossbar, which is arranged on a side of the first crossbar opposite the at least one first core leg; and

a second core body of a ferromagnetic material which comprises a second crossbar having a length dimension and a width dimension, wherein a ratio of length dimension to width dimension is greater than 1, and at least one second core leg which extends laterally away from the second crossbar along a second extension direction,

wherein the first and second core bodies are connected by the at least one first and second core legs.

11. Magnetic core according to claim 10, wherein the second core body comprises a second alignment recess which is formed in a rear surface of the second crossbar, and the rear surface of the second crossbar is arranged on a side of the second crossbar opposite the core legs.

12. Method of forming a magnetic core, comprising:

providing a powder of ferromagnetic material;

pressing of a ferromagnetic material filled into a die for producing a pressed blank, the pressed blank comprising;

a crossbar having a length dimension and a width dimension, wherein a ratio of length dimension to width dimension is greater than 1;

at least one core leg which extends laterally of the crossbar, away therefrom, along an extension direction, and

an alignment recess, and

wherein the die has a structure which produces the alignment recess;

sintering the pressed blank for forming a sintered core body;

aligning the sintered core body relative to a second core body by means of an alignment device having an engagement element that is engaged with the alignment recess of the sintered core body prior to the alignment, wherein the alignment is carried out along directions along the length and width dimensions; and

subsequently

connecting the sintered core body to the second core body to form the magnetic core.

13. Method according to claim 12, wherein the engagement element comprises at least one catch face and/or catch edge so as to engage with the alignment recess.

14. Method according to claim 12, wherein the second core body is another sintered core body and comprises another alignment recess with which another engagement element of the alignment device engages during the alignment.

15. Method according to claim 12, wherein both core bodies each comprise a crossbar and a core leg centrally arranged on the respective crossbar, and the centrally arranged core legs are aligned symmetrically to one another.