JPH04212403A - Magnetic core sheet - Google Patents

Abstract

PURPOSE: To provide thin plate for a magnetic core in a single constitution constituted of an intermediate part and a pair of loop parts arranged at sides faced to this by cutting the middle part in an area faced to the direction of one end across the whole width. CONSTITUTION: A thin plate A is composed of a slender intermediate part 1 having uniform width in the longitudinal direction and a pair of loop parts 2 arranged at sides facing this intermediate part in a plane 8-shaped constitution. Each loop part 2 is extended from the both faced edges of the intermediate part 1, and provided with almost uniform width in the longitudinal direction. Each loop part 2 and the intermediate part 1 form slender and rectangular openings 3 through which a pair of coils are put. The intermediate part is cut at the position of one edge 1, 1 along a line 9 extended vertically to the longitudinal axis across the whole part of the width between comers 6, 6 of the openings 3, 3 at any side.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is applicable to transformers, chokes,
This invention relates to a layered magnetic core suitable for ballasts of lighting equipment, etc.

0002

SUMMARY OF THE INVENTION In accordance with the present invention, there is provided a single magnetic core laminate comprising an elongated intermediate section and a pair of loop sections located on opposite sides of the intermediate section. Each loop portion extends from opposite end regions of the intermediate portion 1 and defines with the intermediate portion an elongated, rectangular opening through which a portion of at least one coil can pass. This sheet is cut across its entire width in a region where the middle part is directed towards one of its ends.

The intermediate section is preferably cut in a straight line substantially perpendicular to the longitudinal axis of the elongated intermediate section and at one end thereof.

Further, according to the present invention, there is provided a thin plate for a magnetic core having a single structure, comprising an elongated intermediate portion and a pair of loop portions disposed on opposite sides of the intermediate portion. Each loop extends from opposite end regions of the intermediate section 1 and defines with the intermediate section an elongated, rectangular opening through which at least a portion of the coil passes. This sheet is cut across its entire width in a region where the middle part is directed towards one of its ends. Therefore, the intermediate part on the one hand and the connected loop part on the other hand can be displaced in the opposite direction relative to the plane of the thin plate in the region of one end of the intermediate part, and the intermediate part can be introduced from one end into the air core of the coil. The coil is then placed around the intermediate portion such that the loop portion encompasses opposing regions of the coil.

[0005] Therefore, in the thin plate of the present invention, the number of rims having a free end and only one cut area is reduced.
To make a thin plate difficult to permanently deform when the thin plate is attached to a coil assembly. Furthermore, because the cut region lies in a straight line across the entire width of the intermediate section, the present sheet can be more easily mass-produced by stamping the sheet from a sheet of a suitable material.

[0006] The intermediate portion and the loop portion are preferably biased by their inherent elasticity to return to their normal position from a relatively displaced position. In this normal position, the portions of the sheet on opposite sides of the cut region are generally aligned to form an air gap therebetween.

The intermediate section preferably has a substantially uniform width along its length, and each of the loop sections has a substantially uniform width along its length. Further, the width of each loop portion is approximately half the width of the intermediate portion.

The aperture defined by each loop portion and the intermediate portion may have an elongated, generally rectangular configuration, with each loop portion including an associated aperture and an elongated outer portion extending along the rectangular aperture. have a part.

[0009] Each loop portion preferably has an outer region that is rounded opposite the corner of the associated rectangular opening so that the width of each loop portion is substantially uniform along its length.

[0010] Each rectangular aperture may be approximately equal to the width of the loop portion, and the length of the aperture is preferably equal to at least three times its width. The magnetic core thin plate according to the present invention preferably has a flat figure-eight shape. The scope of the present invention also includes layered magnetic cores for transformers, chokes, lighting ballasts, or similar stationary appliances constructed by laminating the core sheets as described above. In the most preferred form of the magnetic core, cut regions of the lamellae are sandwiched by uncut regions of adjacent laminas.

[0011] The scope of the present invention also includes transformers, chokes, luminaire ballasts or similar stationary appliances having layered magnetic cores as described in the immediately preceding two paragraphs.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the magnetic core thin plate according to the present invention will be described below with reference to the accompanying drawings.

Referring first to FIG. 1, sheet A is a unitary structure stamped from a sheet of a suitable magnetic material, for example ferrosilicon. The thin plate A has a flat figure-eight configuration and consists of an elongated intermediate portion 1 having a uniform width in the longitudinal direction and a pair of loop portions 2 disposed on sides opposite to the intermediate portion 1. Each loop portion 2 extends from opposite ends of the intermediate portion 1 and has a substantially uniform width along its length.

Each loop section 2, together with the intermediate section 1, defines an elongated, rectangular opening 3 through which a portion of the coil passes. Each loop portion 2 has an elongated outer portion 2.1 extending along the associated elongated opening 3. Each loop portion has rounded corner areas 4, 5 opposite respectively the inner and outer corners 6, 7 of the associated rectangular opening 3, so that each loop portion 2
The width of is approximately uniform along its length. Middle part 1
It can be seen that the two loop parts 2 are connected to each other at both ends. The rounded depression 8 has two loop parts in the middle part 1.
It is formed between the two loop parts 2 in the region where they are joined at both ends.

[0015] At one end 1.1 of the intermediate part, along a line 9 extending over its entire width and perpendicular to its longitudinal axis, inside the openings 3, 3 on either side thereof. is cut between corners 6, 6 of. Opposite end 1 of middle part 1
．． In the area of 2, neither the loop part 2 nor the intermediate part 1 is cut, so that the loop part is fixed with the intermediate part in the area of its opposite end 1.2, thereby providing a sheet of unitary construction.

In a preferred embodiment of the invention, the widths Wl of the two loop parts 2 are equal to each other and 1/2 of the width Wi of the intermediate part.
be equivalent to. The widths Wa of the two openings 3 are equal to each other and equal to the width Wl of the loop portion 2. The lengths La of the openings 3 are equal to each other and are at least three times the width Wa of the openings 3.

The width Wi of the intermediate portion 1 and the width Wl of the two loop portions 2 are selected in accordance with the required power output of a transformer having a magnetic core formed by stacking a plurality of thin plates equal to the thin plate A. The length La of the aperture 3 is appropriately adjusted in relation to the width Wa of the aperture 3 to receive a coil having the appropriate number of turns and/or the appropriate cross-sectional area of the conductor required for the particular application. selected.

The rounded depression 8 has a depth Di of the order of 55% of the width Wl of the loop portion.

A layered magnetic core can be formed by stacking a plurality of identical thin plates to form a stack of aligned thin plates.

As shown in FIGS. 2 and 3, the transformer is manufactured using a magnetic core made of a laminated layer of thin plates equivalent to the thin plates A in FIG. Therefore, the primary winding 10 and the secondary winding 1
Pre-made coil assembly B with a cylindrical structure consisting of 1
will be prepared.

A plurality of thin plates A are successively attached to the coil assembly B one by one. As shown for the lamina A2 in FIG. 2, each lamella has an intermediate section on the one hand and a connected loop section on the other hand, which are opposed apart from each other in the region of one end 1.1 of the intermediate section 1 of the lamina. It is installed by displacing it in the direction. The intermediate part 1 of the sheet is then introduced from one end 13 of the coil assembly B into the air core 12 of the coil assembly, and the loop part 2 passes over the coil assembly B, so that the intermediate part 1 One end 1.1 protrudes from the other end 14 of the coil assembly B. The intermediate part 1 and the loop part 2 are then pushed back from the displaced position to the normal position by the repulsion of the spring under the influence of the inherent elasticity of the material of the thin plate A. In this normal position, the parts of the sheet metal on opposite sides of the region 9 in which the intermediate part 1 is cut lie in alignment. The sheet is then completely flat and the opposing edges 9.1 of the cut region 9 are placed in close registering relation, resulting in a gap 9.2 of uniform minimum width.

Each successive lamina is attached to the coil assembly B described above to form a stack 15 of superimposed lamina A filling the air core 12 of that coil assembly B.

In order to prevent the cut regions 9 of all the laminae A of the stack 15 from superimposing each other in vertically coincident positions, the intermediate parts 1 of successive laminae are arranged in the coil assembly shown in FIG. It is preferably introduced into the air core 12 of the coil assembly alternately from one end 13 and from the other end 14 of the coil assembly shown in FIG. For this purpose, the cut region 9 of one thin plate close to one end 1.1 of the intermediate part is close to the other ends 1.2 of the middle part 1 of the pair of thin plates A on both sides thereof and cut. Not sandwiched between areas of lamina.

Once all the laminae A of the laminate 15 have been attached to the coil assembly B to fill the air core 12 of the coil assembly B, the superimposed laminae A of the laminate 15 are secured together in any suitable manner. can be clamped to provide a laminated core for coil assembly B. Upper and lower clamping plates, not shown, can be provided for this purpose. Bolts (also not shown) for pushing the clamping plates towards each other can pass through alignment recesses 8 at opposite ends of the stack 15.

The lamina A according to the present application has rounded external corner regions 4, 5, providing a double magnetic circuit. This magnetic circuit strengthens the magnetic flux flow around the two circuits and prevents flux leakage and flux eddies from the laminations in the area where they meet towards opposite ends of the intermediate part 1 in the region of the recess 8 or It has a structure that at least minimizes the size.

It will be appreciated that, contrary to the known sheets, the sheet A of the present application need not have any holes for receiving clamping or fixing bolts. This hole lies in the magnetic flux path provided by the lamella and tends to reduce the effective area of that flux path, creating flux vortices in the lamina and eddy currents in the fixing bolt.

Therefore, the efficiency can be improved by using a magnetic core made of a laminated layer of thin plates A according to the present invention. Also, mechanical noise in the thin plates, stray magnetic losses from the magnetic core, and physical coupling with adjacent elements are minimized. Furthermore, the thin plates according to the present invention are conveniently mounted on coil assemblies in which magnetic cores are preformed.

Furthermore, with respect to the thin plate of the present invention in which only one region of the relatively wide middle portion is cut, the thin plate is permanently deformed in the cut region after the thin plate is attached to the hollow magnetic core. The cut area can be made less sensitive so that opposing edges of the cut area can be better aligned and provide a uniform void in the cut area.

The magnetic core thin plate according to the present invention may have many specific variations without departing from the scope and spirit of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a front view of a thin plate for a magnetic core according to the present invention having a flat figure-eight shape.

FIG. 2 is a perspective view from one end of a prefabricated hollow coil assembly for a transformer, illustrating the attachment of laminae similar to FIG. 1 to the coil assembly to create a laminated magnetic core;

FIG. 3 is an enlarged perspective view of the coil assembly of FIG. 2, illustrating the lamination of sheets in accordance with the present application to create a laminated magnetic core for the coil assembly;

Claims (15)

[Claims] 1. A thin plate for a magnetic core of a single structure, consisting of an elongated intermediate section and a pair of loop sections disposed on opposite sides of the intermediate section, each loop section extending from the intermediate section 1. extending from regions of opposite ends of the sheet and defining, together with an intermediate section, an elongated, rectangular opening through which at least a portion of the coil can pass; A thin plate for a magnetic core, characterized in that it is cut across its entire width in the facing area. 2. A magnet according to claim 1, wherein the intermediate section is preferably cut in a straight line substantially perpendicular to the longitudinal axis of the elongated intermediate section and at one end thereof. Thin plate for core. 3. A thin plate for a magnetic core of a single structure consisting of an elongated intermediate section and a pair of loop sections disposed on opposite sides of the intermediate section, each loop section being connected to the intermediate section 1. extending from regions of opposite ends of the sheet and defining, together with an intermediate section, an elongated, rectangular opening through which at least a portion of the coil can pass; cut across its entire width in the area facing, so that the intermediate part on the one hand and the connected loop part on the other hand are displaced in opposite directions relative to the plane of the sheet in the region of one end of the intermediate part A thin plate for a magnetic core, characterized in that the intermediate portion is introduced into the air core of the coil from one end thereof, and the coil is installed around the intermediate portion such that the loop portion encompasses the opposing region of the coil. 4. The intermediate portion and the loop portion are biased by their inherent elasticity to return from a relatively displaced position to a normal position, in which the intermediate portion and the loop portion are on opposite sides of the severed region. 4. A thin plate for a magnetic core according to claim 3, wherein the portions of the thin plate are substantially aligned to form a gap therebetween. 5. A magnetic core sheet according to claim 4, characterized in that edges located very close to each other and in close alignment are provided on opposite sides of the air gap. 6. The intermediate portion according to claim 3, wherein the intermediate portion is cut along a straight line substantially perpendicular to the longitudinal axis of the elongated intermediate portion and at one end of the intermediate portion. Thin plate for magnetic core. 7. The intermediate portion has a substantially uniform width along its length, each of the loop portions has a substantially uniform width along its length, and the width of each loop portion is equal to the width of the intermediate portion. The thin plate for a magnetic core according to any one of claims 1 to 6, characterized in that the thickness is approximately half of that of the magnetic core. 8. The aperture defined by each loop portion and the intermediate portion has an elongated, generally rectangular configuration, and each loop portion includes an associated aperture and an elongated outer portion extending along the rectangular aperture. Claim 1 characterized in that it has
8. The thin plate for a magnetic core according to any one of 7. 9. Each loop portion has an outer region that is rounded opposite a corner of the associated rectangular opening such that the width of each loop portion is substantially uniform along its length. The thin plate for a magnetic core according to claim 8. 10. The magnetic core thin plate according to claim 8, wherein each rectangular opening has a width approximately equal to the width of the loop portion. 11. The thin plate for a magnetic core according to claim 8, wherein the length of the opening is equal to at least three times its width. 12. The thin plate for a magnetic core according to claim 1, wherein the thin plate has a flat figure-eight shape. 13. A transformer, a choke, and a transformer constructed by laminating the magnetic core thin plates according to any one of claims 1 to 12.
Layered magnetic core for luminaire ballasts or similar fixed appliances. 14. The magnetic core according to claim 13, wherein the cut regions of the laminated sheets are sandwiched by uncut regions of adjacent sheets. 15. A transformer, choke, luminaire ballast or similar fixed electrical appliance having a magnetic core according to claim 13 or 14.