DE3910769A1 - Multiple-yoke electromagnet or transformer and method of production thereof - Google Patents

Abstract

A multiple-yoke electromagnet or transformer whose coil bodies (S1, S2) are produced together in one piece and are connected to a flexible bar (10) so that they can be brought into a mutually coaxial position and thereby be continuously wound. The production cost is low, the leakage inductance is low and the heat dissipation of the windings is good. The electromagnets can be used in needle (matrix) print heads. <IMAGE>

Description

The invention relates to a multi-yoke electromagnet or -transformer, whose yokes each have a coil former wear identical windings.

The known multi-yoke electromagnets, chokes or transformers often only carry one on one leg Bobbin with one or more windings, as this Arrangement is easy to manufacture and a small number of Has connections, but a relatively high Stray inductance occurs in the area around the coil and because of an unfavorable due to the relatively small coil surface The heat dissipation capacity of the winding must be accepted.

Furthermore, in the case of known transformers, this is often the one the yoke with the primary winding and the other yoke with one or more secondary windings, where however, there is also a relatively high leakage inductance is. It is known to reduce such undesirable leakage inductances and to increase the Coupling factor both yokes wound in the same way and then intermediate wiring of the same windings whose series connection is made via intermediate contacts, what however, brings increased manufacturing and assembly costs and the probability of failure due to the additional Connections increased.

The object of the invention is a multi-yoke electromagnet or transformer with low leakage inductance, good Heat emission capacity and low manufacturing costs and high Reveal reliability.  

The solution to the problem is that the bobbin are made in one piece by placing them over a flexible web can be brought together in a coaxial position are connected and the windings are each uninterrupted from one of the bobbins to the associated one next coil former are directly connected.

Advantageous configurations are in the subclaims specified.

On the one hand, the simplification of the manufacturing process given that the coil body is injection molded in one piece be produced and thus when winding and assembling can only be handled as one component. Furthermore, the Bobbin when winding around the 180 ° flexible bridge pivoted against each other so that they coaxially with each other connect and runs practically like a coil can be wound. The wires are at each end fixed on injected connector and welded or soldered. After swiveling the These can be moved over the coil body with one hand Push yokes.

The pin-shaped contact connectors that are parallel to the axis Coil axes are standing, when the Coils on the yokes simultaneously in one holes Introduce circuit of a connection board, what a further simplifies work.

Such electromagnets find a preferred application in Needle print heads, where e.g. 24 pcs of which roughly circular, are placed close together and it is important that mutual crosstalk through the leakage inductance is low and the heat emission to the environment is good.

The invention is illustrated with reference to FIGS. 1 to 3.

Fig. 1 shows a double yoke electromagnet assembled and assembled in side view, partly in section;

Fig. 2 shows a top view of a pair of coils before assembly from the contact side;

Fig. 3 shows a wound pair of bobbins in a coaxial position.

Fig. 1 shows a double yoke electromagnet with a U-body ( U ) made of known ferromagnetic material and an armature ( A ) which is pivotally mounted in front of the poles of the U-body ( U ) in the tightened state. The two yokes ( I 1 , I 2 ) are filled with bobbins ( S 1 , S 2 ), which carry windings ( W 1 , W 2 ), the ends of which are welded to contact pins ( K 1 , K 2 ), each in one or the other bobbin ( S 1 , S 2 ) are injected. On the contact pins (K 1, K 2) opposite side of the bobbin (S 1, S 2) is a connecting web (10) between these exists, which is weakened in the middle, so that there is a flexible 180 ° range. The material has been weakened to a thickness ( D ) of approx. 0.2 mm in the central area of the web, so that bending without breaking is possible.

On the contact side, the bobbins ( S 1 , S 2 ) are pulled down to the side of the yokes down to the mounting plate ( M ), so that the support webs ( SS ) formed thereby give a firm lateral hold there, which holds the mounting plate ( M ). the crossbar of the U-body ( U ), in which the crossbar is embedded, added. The support webs ( SS ) are led around to the contacts ( K 1 , K 2 ) and thus form very stable chambers that are open on both sides.

Fig. 2 shows a top view of a pair of coils ( S 1 ; S 2 ) seen on the contacts ( K 1 , K 2 ). The flexible web ( 10 ) is in the middle. The overmolding ( 11 ) of the contacts ( K 1 , K 2 ) has an axially parallel notch ( 12 ) on the outside, through which the wire connection ( 13 ) is guided to the contact.

Fig. 3 shows the plugged arrangement of the two bobbins ( S 1 , S 2 ) in which they are each received in the winding device. The winding wire is led directly as a winding wire connection ( 15 ) over the web ( 10 ) from one winding chamber to the other.

For use in the manufacture of transformers only more contacts provided and if necessary an intermediate insulation between the different Windings inserted. The ferromagnetic cores can be in known way as U-I packets or as a box cut flexible blanks are created. The principle of Stringing together several bobbins by means of flexible Webs for the purpose of coaxial continuous winding and subsequent angled application to the Ferromagnetic carrier bodies can also be used on E-cuts expand and to circular cuts, e.g. to build up Modify motors within the scope of the invention.

The one-piece production of several bobbins and their Coaxial arrangement in the continuous winding is also advantageous for the production of individual coils, the Coils can be separated from the series arrangement if necessary. The one-piece made multiple bobbins and the winding goods made from it are self-employed commercial goods according to the invention.

Claims (9)

1. multi-yoke electromagnet or transformer, the yokes ( I 1 , I 2 ) each carry a coil former ( S 1 , S 2 ), each with identical windings ( W 1 , W 2 ), characterized in that the coil former ( S 1 , S 2 ) are produced in one piece by being connected to each other in a coaxial position via a flexible web ( 10 ) and the windings ( W 1 , W 2 ) are each uninterrupted from one of the coil formers ( S 1 ) to the next coil form connected to them ( S 2 ) are directly connected. 2. multi-yoke electromagnet or transformer according to claim 1, characterized in that the web ( 10 ) between two of the coil former ( S 1 , S 2 ) is weakened in the center, so that it can be bent by at least 180 ° without breaking. 3. multi-yoke electromagnet or transformer according to claim 1 or 2, characterized in that opposite to the web ( 10 ) pin-shaped contacts ( K 1 , K 2 ) in the coil formers ( S 1 , S 2 ) are injected so that they are parallel to the axis Project the coil axis from the bobbins ( S 1 , S 2 ). 4. Multi-yoke electromagnet or transformer according to one of the preceding claims, characterized in that the coil former ( S 1 , S 2 ) parallel to the ferromagnetic yokes ( I 1 , I 2 ) support webs ( SS ). 5. multi-yoke electromagnet or transformer according to claim 4, characterized in that the supporting webs ( SS ) are each connected to one another in the region of the contacts ( K 1 , K 2 ) and the contacts ( K 1 , K 2 ) there by an extrusion coating ( 11 ) are attached. 6. multi-yoke electromagnet or transformer according to claim 5, characterized in that the extrusion coating ( 11 ) has an axially parallel incision ( 12 ) for a wire connection ( 13 ) between each winding space of the coil former ( S 1 , S 2 ) and the contact ( K 1 , K 2 ). 7. multi-yoke electromagnet or transformer according to one of claims 4 to 7, characterized in that the connecting U-web of the U-body ( U ), which carries the yokes ( I 1 , I 2 ), embedded in a mounting plate ( M ) is, on which the support webs ( SS ) sit and are introduced into the holes in which the pin-shaped contacts ( K 1 , K 2 ) are inserted. 8. Multi-yoke electromagnet according to one of claims 1 to 7, characterized in that a hinged armature ( A ) is pivotally arranged in front of the yokes ( I 1 , I 2 ), which carries a pressure needle, and that many of these electromagnets are oriented approximately polar to one another in one Needle print head are arranged. 9. A process for the production of multi-yoke electromagnets or transformers which carry other bobbins ( S 1 , S 2 ) with windings ( W 1 , W 2 ), characterized in that their bobbins ( S 1 , S 2 ) together in one piece with a flexible Connecting bridge ( 10 ) connected by injection molding are made of plastic, the bobbins ( S 1 , S 2 ) are kept arranged coaxially and wound continuously connected and the bobbins ( S 1 , S 2 ) are then placed axially parallel and on yokes ( I 1 , I 2 ) be postponed.