EP0581129A1 - Magnet system for electroacoustic transducers - Google Patents

Magnet system for electroacoustic transducers Download PDF

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Publication number
EP0581129A1
EP0581129A1 EP93111355A EP93111355A EP0581129A1 EP 0581129 A1 EP0581129 A1 EP 0581129A1 EP 93111355 A EP93111355 A EP 93111355A EP 93111355 A EP93111355 A EP 93111355A EP 0581129 A1 EP0581129 A1 EP 0581129A1
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EP
European Patent Office
Prior art keywords
neodymium
air gap
disc
pole core
pole plate
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EP93111355A
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German (de)
French (fr)
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EP0581129B1 (en
Inventor
Gerhard Pfaffinger
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Nokia Technology GmbH
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Nokia Technology GmbH
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    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04RLOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R9/00Transducers of moving-coil, moving-strip, or moving-wire type
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04RLOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R9/00Transducers of moving-coil, moving-strip, or moving-wire type
    • H04R9/02Details
    • H04R9/025Magnetic circuit

Definitions

  • the invention is concerned with magnet systems of electroacoustic transducers, in particular with increasing the magnetic flux density in the air gap while at the same time reducing the size of such systems.
  • Magnet systems of electroacoustic transducers are generally constructed in such a way that the pole core is inserted centrally in a magnet pot to the central axis of the system.
  • the free end of the pole core which is not connected to the bottom of the magnetic pot, is connected to the so-called pole plate.
  • the pole plate has a larger diameter than the pole core.
  • the upper edge of the magnetic pot is connected to a disk protruding into the inner diameter of the magnetic pot or is formed in one piece in the manner described above.
  • the edge areas of the pole plate and the part which run parallel to the central axis and which extend into the inner diameter of the magnetic pot protrudes stand opposite each other at a distance and thus form the air gap of the system.
  • the pole core from a material which is known in the field of converter technology under the name neodymium.
  • This magnetically high-energy material has the advantage over the transducers made in ferrite technology that the transducers constructed in neodymium technology can be considerably reduced in size with the same induction in the air gap compared to the transducers made in ferrite technology.
  • Another consequence of the reduction possible in transducers with neodymium training is the reduction in weight of the magnet system which is associated with the reduction.
  • the advantages associated with the use of neodymium as the material for the pole core are not to be understood in such a way that, starting from a predetermined size of the pole core formed from neodymium, the induction in the air gap can be increased as desired by simply increasing the dimensions of the part of the pole core consisting of neodymium can. Rather, when using neodymium as a material for part of the pole core, it is so that the increase in induction that can be achieved increases only disproportionately as the mass of the neodymium part increases can be increased.
  • the invention is therefore based on the object of specifying a magnet system with a neodymium pole core, the achievable induction of which in the air gap is increased compared to the known arrangements.
  • This object is achieved in that a further neodymium disk is arranged on the side of the pole plate facing away from the bottom of the magnetic pot.
  • a particularly uniform field line course in the air gap is achieved if, according to claim 2, the diameter of both neodymium disks is the same.
  • the masses of the two neodymium discs do not necessarily have to be the same size, this has the advantage that the neodymium disc with the larger of the two masses can be arranged on the pole plate.
  • the consequence of this is that the overall height of the magnet system between the bottom and the pole plate or the upper edge of the magnetic pot can be reduced. Due to the possibility of arranging neodymium disks of different sizes or weights on both sides of the pole plate, the required induction in the air gap can be set in a very simple manner simply by changing the mass of one of the two neodymium disks.
  • this makes it possible to prefabricate a unit formed from the first neodymium disc of the pole plate and the magnetic pot for a large number of loudspeaker types and to set the required induction for the various loudspeaker types by attaching the further neodymium disc.
  • FIG. 1 shows a magnet system 10 for an electroacoustic transducer.
  • This magnet system 10 is essentially formed by that on the magnet pot 11 and the pole core 12.
  • the upper edge of the magnetic pot 10 has a circumferential, unshaped flange 13 which points to the central axis of the system.
  • the pole core 12 is formed from a round disk 14 formed from neodymium and a likewise round pole plate 15, the upper end of the neodymium disk 14 being connected to the pole plate 15. Since the diameter of the pole plate 15 is larger than the diameter of the neodymium disc 14, the upper edge of the pole core 12 is also flange-shaped.
  • the pole core 12 is placed and connected with its end facing away from the pole plate 15 centrally to the central axis on the bottom 16 of the magnet pot 11. Since the height level of the magnetic pot 11 and the height level of the pole core 12 connected to the base 16 are the same and the outer diameter of the pole plate 15 is smaller than the inner diameter of the flange 13, the air gap 17 of the magnet system 10 is formed between the flange 13 and the pole plate 15 .
  • the voice coil (not shown) is later inserted into this air gap 17 to complete the electromagnetic transducer.
  • the further neodymium disc 18 is also placed and connected centrally to the central axis in such a way that the similar poles (here the two north poles; N / N) of the two neodymium discs 14, 18 directly and only through one another the pole plate 15 are separately opposite.
  • the diameter the further neodymium disc 18 corresponds to the diameter of the neodymium disc 14 arranged in the pole core 12. This equality in the diameter of both neodymium discs 14, 18 ensures that the field line profile in the air gap 17 has a particularly uniform profile.
  • a further weight saving by using two neodymium discs 14, 18 on both sides of the pole plate 15 resulted from the fact that Because of the reduced mass for the first neodymium disk 14 arranged in the pole core 12, the design of the magnetic pot 11 can also be reduced.
  • FIGS. 2a, b show, it is not necessary that the dimensions and thus also the designs of the two neodymium disks 14, 18 on both sides of the pole plate 15 have to be chosen to be the same size. Rather, in deviation from the illustration in FIG. 1, the neodymium disc 14 arranged in the pole plate 15 can also be made smaller or larger than the other neodymium disc 18. This combination possibility makes it possible to prefabricate the magnet pot 11 together with the pole core 12 for a large number of loudspeaker types and to adjust the final setting of the induction in the air gap 17 required for the different types by arranging different sized additional neodymium discs 18 on the pole plate 15.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)
  • Electrostatic, Electromagnetic, Magneto- Strictive, And Variable-Resistance Transducers (AREA)

Abstract

According to the prior art, magnet systems for electroacoustic transducers are known, the pole core (12) of which exhibits a neodymium disc (14). If the inductance in the air gap (17) is to be increased, it is known in the prior art to increase the mass of the neodymium disc (14) in the pole core (12). However, the inductance can only be increased by between 5 and 8 % of the initial inductance by means of this measure. The invention is therefore based on the object of specifying a magnet system (10) which allows the inductance in the air gap (17) to be significantly increased. This is achieved by the fact that a further neodymium disc (18) is arranged on the side of the pole plate (15) facing away from the bottom (16) of the magnet pot (11). Due to the significant increase in inductance in the air gap (17) which can be achieved in accordance with the invention, it is possible to minimise the use of neodymium material in spite of the arrangement of two neodymium discs (14, 18). <IMAGE>

Description

Technisches GebietTechnical field

Die Erfindung befaßt sich mit Magnetsystemen von elektroakustischen Wandlern, insbesondere mit der Steigerung der magnetischen Flußdichte im Luftspalt bei gleichzeitiger Verkleinerung der Bauform solcher Systeme.The invention is concerned with magnet systems of electroacoustic transducers, in particular with increasing the magnetic flux density in the air gap while at the same time reducing the size of such systems.

Stand der TechnikState of the art

Magnetsysteme von elektroakustischen Wandlern sind allgemein so aufgebaut, daß in einem Magnettopf der Polkern zentrisch zur Mittelachse des Systems eingesetzt ist. Das freie, nicht mit dem Boden des Magnettopfes verbundene Ende des Polkerns ist mit der sogenannten Polplatte verbunden. Die Polplatte hat gegenüber dem Polkern einen größeren Durchmesser. Je nach Ausmessung des Magnettopfes ist der obere Rand des Magnettopfes mit einer in den Innendurchmesser des Magnettopfes hineinragenden Scheibe verbunden oder einstückig in der vorbeschriebenen Weise ausgebildet. Die parallel zur Mittelachse verlaufenden Randbereiche von der Polplatte und dem Teil, welches in den Innendurchmesser des Magnettopfes hineinragt, stehen einander mit Abstand gegenüber und bilden so den Luftspalt des Systems.Magnet systems of electroacoustic transducers are generally constructed in such a way that the pole core is inserted centrally in a magnet pot to the central axis of the system. The free end of the pole core, which is not connected to the bottom of the magnetic pot, is connected to the so-called pole plate. The pole plate has a larger diameter than the pole core. Depending on the dimensions of the magnetic pot, the upper edge of the magnetic pot is connected to a disk protruding into the inner diameter of the magnetic pot or is formed in one piece in the manner described above. The edge areas of the pole plate and the part which run parallel to the central axis and which extend into the inner diameter of the magnetic pot protrudes, stand opposite each other at a distance and thus form the air gap of the system.

Herkömmlich werden solche Magnetsysteme weitgehend aus Ferritmaterial gebildet. Um eine ausreichend große magnetische Flußdichte im Luftspalt zu erzielen, ist es bei den aus Ferritmaterial gebildeten Anordnungen erforderlich, das Magnetsystem bezogen auf die übrige Masse der Lautsprecheranordnung groß und daher schwer auszubilden.Conventionally, such magnet systems are largely formed from ferrite material. In order to achieve a sufficiently large magnetic flux density in the air gap, it is necessary for the arrangements formed from ferrite material to make the magnet system large in relation to the remaining mass of the loudspeaker arrangement and therefore difficult to design.

Daneben ist es bekannt, den Polkern aus einem Material zu bilden, welches auf dem Gebiet der Wandlertechnik unter der Bezeichung Neodym bekannt ist. Der Einsatz dieses magnetisch hochenergetischen Materials hat gegenüber der in Ferrittechnologie erstellten Wandler den Vorteil, daß die in Neodymtechnologie ausgebildeten Wandler bei gleicher Induktion im Luftspalt gegenüber den in Ferrittechnologie gebildeten Wandlern erheblich verkleinert werden können. Eine weitere Folge der bei Wandlern in Neodymausbildung möglichen Verkleinerung ist, die mit der Verkleinerung einhergehende Gewichtsreduzierung des Magnetsystems.In addition, it is known to form the pole core from a material which is known in the field of converter technology under the name neodymium. The use of this magnetically high-energy material has the advantage over the transducers made in ferrite technology that the transducers constructed in neodymium technology can be considerably reduced in size with the same induction in the air gap compared to the transducers made in ferrite technology. Another consequence of the reduction possible in transducers with neodymium training is the reduction in weight of the magnet system which is associated with the reduction.

Die mit der Verwendung von Neodym als Material für den Polkern verbundenen Vorteile sind aber nicht so zu verstehen, daß ausgehend von einer vorgegebenen Größe des aus Neodym gebildeten Polkerns die Induktion im Luftspalt durch bloße Vergrößerung der Abmessungen des aus Neodym bestehenden Teils des Polkerns beliebig gesteigert werden kann. Vielmehr ist es auch bei der Verwendung von Neodym als Material für einen Teil des Polkerns so, daß mit zunehmender Vergrößerung der Masse des Neodymteils die erzielbare Induktionssteigerung nur unterproportional erhöht werden kann. Um dies an einem Beispiel zu verdeutlichen, sei darauf hingewiesen, daß bei einer Masse des Neodymteils im Polkern von x eine Induktion (BL) im Luftspalt von etwa 0,6 Tesla erzielbar ist, während bei einer Erhöhung der Masse des Neodymteils im Polkern auf 2x die im Luftspalt erzielbare Induktion nur auf etwa 0,645 Tesla gesteigert werden kann.However, the advantages associated with the use of neodymium as the material for the pole core are not to be understood in such a way that, starting from a predetermined size of the pole core formed from neodymium, the induction in the air gap can be increased as desired by simply increasing the dimensions of the part of the pole core consisting of neodymium can. Rather, when using neodymium as a material for part of the pole core, it is so that the increase in induction that can be achieved increases only disproportionately as the mass of the neodymium part increases can be increased. To illustrate this with an example, it should be pointed out that with a mass of the neodymium part in the pole core of x, an induction (B L ) in the air gap of approximately 0.6 Tesla can be achieved, while with an increase in the mass of the neodymium part in the pole core 2x the induction that can be achieved in the air gap can only be increased to about 0.645 Tesla.

Daher liegt der Erfindung die Aufgabe zugrunde, ein Magnetsystem mit Neodympolkern anzugeben, dessen erzielbare Induktion im Luftspalt gegenüber den bekannten Anordnungen gesteigert ist.The invention is therefore based on the object of specifying a magnet system with a neodymium pole core, the achievable induction of which in the air gap is increased compared to the known arrangements.

Darstellung der ErfindungPresentation of the invention

Diese Aufgabe wird dadurch gelöst, daß gemäß Anspruch 1 an der dem Boden des Magnettopfes abgewandten Seite der Polplatte eine weitere Neodymscheibe angeordnet ist.This object is achieved in that a further neodymium disk is arranged on the side of the pole plate facing away from the bottom of the magnetic pot.

Mittels dieser Anordnung ist es möglich, die erzielbare Induktion im Luftspalt gegenüber der herkömmlichen Ausbildung um bis zu 50 % zu steigern.With this arrangement, it is possible to increase the achievable induction in the air gap by up to 50% compared to the conventional design.

Aufgrund der mit dieser Anordnung erzielbaren Induktionssteigerung ist es weiter möglich, die Masse des Magnetsystems insgesamt zu reduzieren. Ist beispielsweise eine Induktion von 0,65 Tesla im Luftspalt erforderlich und wurde dafür bisher eine Neodymscheibe im Polkern mit der Masse von 2x verwendet, so kann die gleiche Induktion im Luftspalt dadurch erzielt werden, daß die Masse der Neodymscheibe im Polkern auf 0,6 x reduziert wird und diese Anordnung mit einer weiteren auf der Polplatte aufgesetzten Neodymscheibe mit einer Masse von etwa 0,6x kombiniert wird.Because of the increase in induction that can be achieved with this arrangement, it is also possible to reduce the mass of the magnet system as a whole. If, for example, an induction of 0.65 Tesla in the air gap is required and a neodymium disk with a mass of 2x was previously used for this, the same induction in the air gap can be achieved by increasing the mass of the neodymium disk in the pole core to 0.6 x is reduced and this arrangement is combined with a further neodymium disc placed on the pole plate and having a mass of approximately 0.6x.

Ein besonders gleichmäßiger Feldlinienverlauf im Luftspalt ist dann erreicht, wenn gemäß Anspruch 2 der Durchmesser beider Neodymscheiben gleich ist.A particularly uniform field line course in the air gap is achieved if, according to claim 2, the diameter of both neodymium disks is the same.

Da gemäß Anspruch 3 die Massen der beiden Neodymscheiben nicht notwendig gleich groß sein müssen, hat dies den Vorteil, daß die Neodymscheibe mit der größeren der beiden Massen auf der Polplatte angeordnet werden kann. Dies hat zur Folge, daß die Bauhöhe des Magnetsystems zwischen dem Boden und der Polplatte beziehungweise dem oberen Rand des Magnettopfes verkleinert werden kann. Durch die Möglichkeit unterschiedlich große beziehungweise schwere Neodymscheiben beiderseits der Polplatte anzuordnen, kann durch bloße Veränderung der Masse von einer der beiden Neodymscheiben die erforderliche Induktion im Luftspalt in sehr einfacher Weise eingestellt werden. Insbesondere ist es dadurch möglich, ein aus der ersten Neodymscheibe der Polplatte und dem Magnettopf gebildete Einheit für eine Vielzahl von Lautsprechertypen vorzufertigen und durch das Ansetzen der weiteren Neodymscheibe die erforderliche Induktion für die verschiedenen Lautsprechertypen einzustellen.Since, according to claim 3, the masses of the two neodymium discs do not necessarily have to be the same size, this has the advantage that the neodymium disc with the larger of the two masses can be arranged on the pole plate. The consequence of this is that the overall height of the magnet system between the bottom and the pole plate or the upper edge of the magnetic pot can be reduced. Due to the possibility of arranging neodymium disks of different sizes or weights on both sides of the pole plate, the required induction in the air gap can be set in a very simple manner simply by changing the mass of one of the two neodymium disks. In particular, this makes it possible to prefabricate a unit formed from the first neodymium disc of the pole plate and the magnetic pot for a large number of loudspeaker types and to set the required induction for the various loudspeaker types by attaching the further neodymium disc.

Kurze Darstellung der FigurenBrief presentation of the figures

Figur 1Figure 1
Ein Magnetsystem für einen elektroakustischen Wandler im Seitenschnitt; undA magnet system for an electroacoustic transducer in side section; and
Figur 2a, bFigure 2a, b
zwei weitere Magnetsysteme im Seitenschnitt.two further magnet systems in side section.
Wege zum Ausführen der ErfindungWays of Carrying Out the Invention

Die Erfindung soll nun anhand der Figuren näher erläutert werden.The invention will now be explained in more detail with reference to the figures.

Figur 1 zeigt ein Magnetsystem 10 für einen elektroakustischen Wandler. Dieses Magnetsystem 10 wird im wesentlichen von dem am Magnettopf 11 und dem Polkern 12 gebildet. Der obere Rand des Magnettopfes 10 weist einen umlaufenden, zur Mittelachse des Systems weisenden ungeformten Flansch 13 auf. Der Polkern 12 ist aus einer runden aus Neodym gebildeten Scheibe 14 und einer gleichfalls runden Polplatte 15 gebildet, wobei das obere Ende der Neodymscheibe 14 mit der Polplatte 15 verbunden ist. Da der Durchmesser der Polplatte 15 gegenüber dem Durchmesser der Neodymscheibe 14 größer gewählt ist, ist auch der obere Rand des Polkerns 12 flanschförmig ausgebildet. Der Polkern 12 ist mit seinem der Polplatte 15 abgewandten Ende zentrisch zur Mittelachse auf dem Boden 16 des Magnettopfes 11 aufgesetzt und verbunden. Da das Höhenniveau des Magnettopfes 11 und das Höhenniveau des mit dem Boden 16 verbundenen Polkerns 12 gleich ist und der Außendurchmesser der Polplatte 15 kleiner als der Innendurchmesser des Flansches 13 ist, wird zwischen dem Flansch 13 und der Polplatte 15 der Luftspalt 17 des Magnetsystems 10 gebildet. In diesen Luftspalt 17 wird später zur Komplettierung des elektromagnetischen Wandlers die Schwingspule (nicht dargestellt) eingesetzt. Auf der der ersten Neodymscheibe 14 abgewandten Seite der Polplatte 15 ist ebenfalls zentrisch zur Mittelachse die weitere Neodymscheibe 18 so aufgesetzt und verbunden, daß die gleichartigen Pole (hier die beiden Nordpole; N/N) der beiden Neodymscheiben 14, 18 einander direkt und nur durch die Polplatte 15 getrennt gegenüber liegen. Der Durchmeser der weiteren Neodymscheibe 18 entspricht dem Durchmesser der im Polkern 12 angordneten Neodymscheibe 14. Diese Gleichheit im Durchmesser beider Neodymscheiben 14, 18 gewährleistet, daß der Feldlinienverlauf im Luftspalt 17 einen besonders gleichmäßigen Verlauf aufweist.Figure 1 shows a magnet system 10 for an electroacoustic transducer. This magnet system 10 is essentially formed by that on the magnet pot 11 and the pole core 12. The upper edge of the magnetic pot 10 has a circumferential, unshaped flange 13 which points to the central axis of the system. The pole core 12 is formed from a round disk 14 formed from neodymium and a likewise round pole plate 15, the upper end of the neodymium disk 14 being connected to the pole plate 15. Since the diameter of the pole plate 15 is larger than the diameter of the neodymium disc 14, the upper edge of the pole core 12 is also flange-shaped. The pole core 12 is placed and connected with its end facing away from the pole plate 15 centrally to the central axis on the bottom 16 of the magnet pot 11. Since the height level of the magnetic pot 11 and the height level of the pole core 12 connected to the base 16 are the same and the outer diameter of the pole plate 15 is smaller than the inner diameter of the flange 13, the air gap 17 of the magnet system 10 is formed between the flange 13 and the pole plate 15 . The voice coil (not shown) is later inserted into this air gap 17 to complete the electromagnetic transducer. On the side of the pole plate 15 facing away from the first neodymium disc 14, the further neodymium disc 18 is also placed and connected centrally to the central axis in such a way that the similar poles (here the two north poles; N / N) of the two neodymium discs 14, 18 directly and only through one another the pole plate 15 are separately opposite. The diameter the further neodymium disc 18 corresponds to the diameter of the neodymium disc 14 arranged in the pole core 12. This equality in the diameter of both neodymium discs 14, 18 ensures that the field line profile in the air gap 17 has a particularly uniform profile.

Zur Verdeutlichung der durch diese Anordnung der weiteren Neodymscheibe 18 erzielbaren Induktionssteigerung sei auf folgendes hingewiesen: Wäre mittels einer Anordnung gemäß Figur 1, bei welcher lediglich die weitere Neodymscheibe 18 weggelassen ist, eine Induktion von beispielsweise 0,6 Tesla erzielbar und würde man zur Erhöhung der Induktion im Luftspalt 17 die Masse der Neodymscheibe 14 im Polkern 12 um die Masse der weiteren Neodymscheibe 18 vergrößern, wäre wegen der damit verbundenen Vergrößerung des Magnettopfes 11 lediglich eine Induktionssteigerung zwischen 5 und 8 % erzielbar. Wird jedoch der Magnettopf 11 so ausgebildet, wie es in Figur 1 veranschaulicht ist, kann damit gegenüber einem Magnetsystem 10, welches nur die Neodymscheibe 14 im Polkern aufweist, eine Erhöhung der Induktion im Luftspalt 17 von bis zu 50 % erzielt werden. Die nach der Erfindung erzielbaren Vorteile, welche mit der Anordnung der zweiten Neodymscheibe 18 verbunden sind, können auch dazu genutzt werden, den Neodymeinsatz zu minimieren. Ist nämlich eine vorgegebene Induktion im Luftspalt 17 erforderlich und kann diese Induktion mittels einer im Polkern 12 angeordneten Neodymscheibe 14 der Masse 2x erreicht werden, kann die gleiche Induktion durch den Einsatz zweier Neodymscheiben 14, 18 mit einer Gesamtmasse von etwa 1,2 x erreicht werden, wenn diese Masse beiderseits der Polplatte 15 auf zwei Neodymscheiben 14, 18 aufgeteilt wird. Eine weitere Gewichtsersparnis durch den Einsatz zweier Neodymscheiben 14, 18 beiderseits der Polplatte 15 folgte daraus, daß wegen der verkleinerten Masse für die erste, im Polkern 12 angeordneten Neodymscheibe 14 auch der Magnettopf 11 in seiner Bauform verkleinert werden kann.In order to clarify the increase in induction that can be achieved by this arrangement of the further neodymium disc 18, the following should be pointed out: If an arrangement according to FIG. 1, in which only the further neodymium disc 18 is omitted, an induction of, for example, 0.6 Tesla could be achieved and one would increase the If induction in the air gap 17 increases the mass of the neodymium disk 14 in the pole core 12 by the mass of the further neodymium disk 18, only an increase in induction of between 5 and 8% could be achieved due to the enlargement of the magnetic pot 11 associated therewith. However, if the magnetic pot 11 is configured as illustrated in FIG. 1, an increase in the induction in the air gap 17 of up to 50% can be achieved compared to a magnet system 10 which only has the neodymium disk 14 in the pole core. The advantages achievable according to the invention, which are associated with the arrangement of the second neodymium disc 18, can also be used to minimize the use of neodymium. If a given induction in the air gap 17 is required and this induction can be achieved by means of a neodymium disc 14 arranged in the pole core 12 and having the mass 2x, the same induction can be achieved by using two neodymium discs 14, 18 with a total mass of approximately 1.2 x if this mass is divided on both sides of the pole plate 15 on two neodymium disks 14, 18. A further weight saving by using two neodymium discs 14, 18 on both sides of the pole plate 15 resulted from the fact that Because of the reduced mass for the first neodymium disk 14 arranged in the pole core 12, the design of the magnetic pot 11 can also be reduced.

Wie die Figuren 2a, b zeigen, ist es nicht erforderlich, daß die Massen und damit auch die Bauformen der beiden Neodymscheiben 14, 18 beiderseits der Polplatte 15 gleich groß gewählt werden müssen. Vielmehr kann in Abweichung zur Darstellung in Fig. 1 auch die im Polplatte 15 angeordnete Neodymscheibe 14 kleiner oder größer der weiteren Neodymscheibe 18 ausgebildet sein. Diese Kombinationsmöglichkeit erlaubt es, den Magnettopf 11 mitsamt dem Polkern 12 für eine Vielzahl von Lautsprechertypen vorzufertigen und die endgültige Einstellung der für die verschiedenen Typen erforderlichen Induktion im Luftspalt 17 durch Anordnung verschieden großer weiterer Neodymscheiben 18 auf der Polplatte 15 einzustellen.As FIGS. 2a, b show, it is not necessary that the dimensions and thus also the designs of the two neodymium disks 14, 18 on both sides of the pole plate 15 have to be chosen to be the same size. Rather, in deviation from the illustration in FIG. 1, the neodymium disc 14 arranged in the pole plate 15 can also be made smaller or larger than the other neodymium disc 18. This combination possibility makes it possible to prefabricate the magnet pot 11 together with the pole core 12 for a large number of loudspeaker types and to adjust the final setting of the induction in the air gap 17 required for the different types by arranging different sized additional neodymium discs 18 on the pole plate 15.

Claims (3)

Magnetsystem für elektroakustische Wandler - mit einem Magnettopf und - mit einem Polkern, der von einer Neodymscheibe (14) und einer Polplatte gebildet ist und der zentrisch zur Lautsprechermittelachse mit dem Boden des Magnettopfes verbunden ist,
dadurch gekennzeichnet,
daß zur Induktionssteigerung im Luftspalt (17) an der der Neodymscheibe (14) abgewandten Seite der Polplatte (15) eine weitere Neodymscheibe (18) angeordnet ist.
Magnet system for electro-acoustic transducers - with a magnetic pot and with a pole core which is formed by a neodymium disc (14) and a pole plate and which is connected to the bottom of the magnetic pot centrally to the loudspeaker center axis,
characterized by
that a further neodymium disc (18) is arranged in the air gap (17) on the side of the pole plate (15) facing away from the neodymium disc (14).
Magnetsystem gemäß Anspruch 1,
dadurch gekennzeichnet,
daß der Durchmesser der weiteren Neodymscheibe (18) dem Durchmesser der im Polkern (12) angordneten Neodymscheibe (14) entspricht.
Magnet system according to claim 1,
characterized by
that the diameter of the further neodymium disc (18) corresponds to the diameter of the neodymium disc (14) arranged in the pole core (12).
Magnetsystem gemäß Anspruch 1 oder Anspruch 2,
dadurch gekennzeichnet,
daß die Masse der ersten Neodymscheibe (14) von der Masse der weiteren Neodymscheibe (18) verschieden ist.
Magnet system according to claim 1 or claim 2,
characterized by
that the mass of the first neodymium disc (14) is different from the mass of the other neodymium disc (18).
EP19930111355 1992-07-30 1993-07-15 Magnet system for electroacoustic transducers Expired - Lifetime EP0581129B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19924225156 DE4225156A1 (en) 1992-07-30 1992-07-30 Magnet system for electro-acoustic transducers
DE4225156 1992-07-30

Publications (2)

Publication Number Publication Date
EP0581129A1 true EP0581129A1 (en) 1994-02-02
EP0581129B1 EP0581129B1 (en) 1996-09-18

Family

ID=6464440

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19930111355 Expired - Lifetime EP0581129B1 (en) 1992-07-30 1993-07-15 Magnet system for electroacoustic transducers

Country Status (4)

Country Link
EP (1) EP0581129B1 (en)
JP (1) JPH06163240A (en)
DE (2) DE4225156A1 (en)
DK (1) DK0581129T3 (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5898786A (en) * 1996-05-10 1999-04-27 Nokia Technology Gmbh Loudspeakers
EP1248494A2 (en) 2001-03-23 2002-10-09 S.I.P.E. Società Italiana Prodotti Elettromeccanici - S.p.A. Cup-shaped loudspeaker armature with magnets from neodymium
US7068807B2 (en) * 2003-11-17 2006-06-27 Sony Corporation Speaker device
US7233680B2 (en) 2003-11-17 2007-06-19 Sony Corporation Speaker device
US7480391B2 (en) 2003-11-18 2009-01-20 Sony Corporation Speaker gasket and its manufacturing method, and speaker device
US7894623B2 (en) 2006-03-22 2011-02-22 Harman International Industries, Incorporated Loudspeaker having an interlocking magnet structure
US9854365B2 (en) 2016-04-15 2017-12-26 Harman International Industries, Inc. Loudspeaker motor and suspension system

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19808688C2 (en) * 1997-03-05 2002-12-12 Harman Audio Electronic Sys Magnet system and method for its manufacture
GB2371165B (en) * 2001-01-16 2004-12-22 Kh Technology Magnet system for loudspeakers

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2188790A (en) * 1986-04-04 1987-10-07 Data Recording Instr Co Switched stator winding for an electric motor
EP0341926A1 (en) * 1988-05-09 1989-11-15 Kh Technology Corporation Loudspeaker
US4926896A (en) * 1988-12-23 1990-05-22 Dresser Industries, Inc. Sensitive electrical to mechanical transducer

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3936639C1 (en) * 1989-11-03 1991-03-07 Mercedes-Benz Aktiengesellschaft, 7000 Stuttgart, De Permanent magnet arrangement e.g. for vehicle loudspeaker - includes associated oscillatory coil arrangement to drive loudspeaker diaphragm
DE4021651C1 (en) * 1990-07-07 1991-06-27 Mercedes-Benz Aktiengesellschaft, 7000 Stuttgart, De

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2188790A (en) * 1986-04-04 1987-10-07 Data Recording Instr Co Switched stator winding for an electric motor
EP0341926A1 (en) * 1988-05-09 1989-11-15 Kh Technology Corporation Loudspeaker
US4926896A (en) * 1988-12-23 1990-05-22 Dresser Industries, Inc. Sensitive electrical to mechanical transducer

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5898786A (en) * 1996-05-10 1999-04-27 Nokia Technology Gmbh Loudspeakers
EP1248494A2 (en) 2001-03-23 2002-10-09 S.I.P.E. Società Italiana Prodotti Elettromeccanici - S.p.A. Cup-shaped loudspeaker armature with magnets from neodymium
EP1248494A3 (en) * 2001-03-23 2006-03-08 S.I.P.E. Società Italiana Prodotti Elettromeccanici - S.p.A. Cup-shaped loudspeaker armature with magnets from neodymium
US7068807B2 (en) * 2003-11-17 2006-06-27 Sony Corporation Speaker device
US7233680B2 (en) 2003-11-17 2007-06-19 Sony Corporation Speaker device
US7480391B2 (en) 2003-11-18 2009-01-20 Sony Corporation Speaker gasket and its manufacturing method, and speaker device
US7894623B2 (en) 2006-03-22 2011-02-22 Harman International Industries, Incorporated Loudspeaker having an interlocking magnet structure
US8315421B2 (en) 2006-03-22 2012-11-20 Harman International Industries, Incorporated Loudspeaker having an interlocking magnet structure
US9854365B2 (en) 2016-04-15 2017-12-26 Harman International Industries, Inc. Loudspeaker motor and suspension system
US10051374B2 (en) 2016-04-15 2018-08-14 Harman International Industries, Incorporated Loudspeaker motor and suspension system

Also Published As

Publication number Publication date
DK0581129T3 (en) 1997-03-17
DE59303831D1 (en) 1996-10-24
JPH06163240A (en) 1994-06-10
DE4225156A1 (en) 1994-02-03
EP0581129B1 (en) 1996-09-18

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