SE506979C2

SE506979C2 - Electromagnetic converter and way to mount it

Info

Publication number: SE506979C2
Application number: SE9602701A
Authority: SE
Inventors: Mikael Carlsson
Original assignee: Nokia Audio & Electronics Ab
Priority date: 1996-07-08
Filing date: 1996-07-08
Publication date: 1998-03-09
Also published as: SE9602701D0; SE9602701L; AU3638097A; WO1998002017A1

Abstract

The invention relates to an electromagnetic converter for reproducing sound as well as to a method for assembling an electromagnetic converter. The converter comprises a so called inverted loudspeaker consisting of voice coil means (1), a magnetic circuit (5-6, 8-11) and a diaphragm (2) which are to be assembled in a basket (4). The magnetic circuit comprises a pre-magnetisable magnet (10). There can also be two pre-magnetisable magnet disks (5, 10) of opposite polarisation on either side of a magnet core in two parts (6, 11). In order to join the core parts (6, 11) with great precision, male and female guiding means (6:1, 11:1) are arranged on the core parts (6, 11).

Description

15 20 30 2 Koågékrgrlzigg av uppﬁnningen och dess fördelar Föreliggande uppﬁnning har som ändamål att åstadkomma en högtalare där membranet är täckt så litet som möjligt för att därigenom öka ljudkvaliteten. The object of the present invention is to provide a loudspeaker in which the diaphragm is covered as little as possible in order to thereby increase the sound quality.

Enligt uppﬁnningen kan de i högtalaren ingående delarna sättas fast utan att membranet täcks i onödan av ljudstörande fastsättningsdelar, såsom ribbor eller frontdelar. Enligt uppﬁnningen är således hela membranytan öppen, utom den del som täcks av en mittkåpa, varvid akustiska fördelar vinnes.According to the invention, the parts included in the speaker can be fixed without the diaphragm being unnecessarily covered by sound-disturbing fastening parts, such as ribs or front parts. According to the invention, the entire membrane surface is thus open, except for the part covered by a central cover, whereby acoustic advantages are gained.

Ett annat ändamål för föreliggande uppﬁnning är att tillhandahålla en högtalare där monteringen av magnetdon och talspoledon kan göras så exakt som möjligt.Another object of the present invention is to provide a loudspeaker in which the mounting of magnetic devices and voice coils can be done as accurately as possible.

Detta åstadkommes genom att speciella styrdon ﬁnns för hopsättningen av magneterna, vilka styrdon behövs på grund av de starka magnetkrafter i sidled som ﬁnns vid en magnetanordning enligt ovan. På grund av dessa styrdon kan högtalaren lätt monteras med mycket små luftgap mellan talspole magnetpoler.This is achieved by providing special control devices for the assembly of the magnets, which control devices are needed due to the strong lateral magnetic forces found in a magnetic device as above. Due to these controllers, the speaker can be easily mounted with very small air gaps between the voice coil magnetic poles.

Den elektromagnetiska omvandlaren enligt uppﬁnningen har dessutom låg vikt, den är platt och kompakt i djupled, vilket ofta är önskvärt, t ex om den skall byggas in i en bildörr. Den har dessutom en enkel uppbyggnad och är därför billig att framställa.The electromagnetic transducer according to the invention also has a low weight, it is flat and compact in depth, which is often desirable, for example if it is to be built into a car door. It also has a simple structure and is therefore cheap to manufacture.

Genom att effektivt magnetmaterial, såsom neodym el dyl, används är omvandlaren lätt, vilket kan vara en stor fördel vid många tillämpningar.By using efficient magnetic material, such as neodymium or the like, the converter is lightweight, which can be a great advantage in many applications.

Beskrivning av ett utföringsexempel Uppﬁnningen beskrivs närmare nedan med hjälp av ett på ritningen visat utföringsexempel. Därvid visar: Figur 1 en vertikal sektionsvy av en elektromagnetiska omvandlare enligt uppﬁnningen.Description of an embodiment The invention is described in more detail below with the aid of an embodiment shown in the drawing. In this case: Figure 1 shows a vertical sectional view of an electromagnetic transducer according to the invention.

Figur 2 en förstorad vy av magnetsystemet samt talspoledon. 10 15 20 30 9.79_ l ﬁguren 1 och 2 betecknar 1 ett talspoledon bestående av en talspo|e51çll6som ar monterad utanpå en spolbärare 1:2. l utföringsexemplet är talspolen anordnad nära den hylsformade spolbärarens 1:2 främre ände. Talspolen 1:1, som kan utgöras av tex koppartråd eller motsvarande, är enligt utföringsexemplet Iindad på spolbäraren 1:2 _ Talspoledonet 1 är anordnat i centrumhålet hos ett konformat membran 2. Tal- spoledon 1 och membran 2 limmas därvid med varandra vid spolbärarens bakre ände. _ x Såsom visas i ﬁgur 1 är talspolens anslutningstrådar 1:3 fastlimmade i membranet och förda ut till en yttre anslutning 1:4. Spolbäraren 1:2 utgöres av plast, aluminium eller dyl. Membranet 2 utgöres företrädesvis av glasﬁber eller av plast, Kevlar®, papper eller liknande.Figure 2 is an enlarged view of the magnetic system and speech coil. 10 15 20 30 9.79_ Figures 1 and 2 denote a speech coil consisting of a voice coil mounted on the outside of a coil carrier 1: 2. In the exemplary embodiment, the speech coil is arranged near the front end of the sleeve-shaped coil carrier 1: 2. The number coil 1: 1, which may consist of, for example, copper wire or the like, is according to the embodiment wound on the coil carrier 1: 2. The number coil 1 is arranged in the center hole of a cone-shaped membrane 2. Number coil 1 and diaphragm 2 are glued together at End. _ x As shown in Figure 1, the connection coils 1: 3 of the voice coil are glued to the diaphragm and extended to an external connection 1: 4. The coil carrier 1: 2 consists of plastic, aluminum or the like. The membrane 2 is preferably made of glass or of plastic, Kevlar®, paper or the like.

Ett första fästdon 3, tex av stål, aluminium eller plast, är fäst vid högtalarens korg 4, antingen med nitning, limning, snäppning eller på annat sätt. Fästdonet 3 kan även vara integrerat med korgen 4. Enligt utföringsexemplet utgöres fästdonet av ett T- format don, vars horisontella del fästes på korgens undersida och vars vertikala del sträcker sig inåt, framåt genom korgens botten. På den främre sidan kan ett förmagnetiserbart magnetdon 5, t ex en neodymdisk, fästas och på detta limmas en första kärndel 6 med ett han-organ 6:1, företrädesvis bestående en konformad centrumtapp. Magnetdonet 5 kan uteslutas. I korgen 4 ﬁnns anordnad ett fjädrande centreringsdon 7 som är fäst vid korgens 4 insida. Centreringsdonet 7 kan var av väv eller annat fjädrande material.A first fastener 3, for example of steel, aluminum or plastic, is attached to the speaker basket 4, either by riveting, gluing, snapping or in another way. The fastener 3 can also be integrated with the basket 4. According to the exemplary embodiment, the fastener consists of a T-shaped device, the horizontal part of which is fastened to the underside of the basket and whose vertical part extends inwards, forwards through the bottom of the basket. On the front side, a pre-magnetisable magnetic device 5, for example a neodymium disk, can be attached and on this a first core part 6 is glued with a male member 6: 1, preferably consisting of a cone-shaped center pin. The magnet device 5 can be excluded. Arranged in the basket 4 is a resilient centering device 7 which is attached to the inside of the basket 4. The centering device 7 may be of fabric or other resilient material.

Talspoledon 1 och membran 2 påföres och limmas nu med det framåtskjutande fästdonet 3 uppbärande det förmagnetiserbara magnetdonet 5, om detta ﬁnns, och den första kärndelen 6. Limningen sker med hjälp av en s.k. styrﬁxtur mellan spolbäraren 1:2 och den första kärndelen 6. Membranet 2 anslutes därvid till den fjädrande centreringen 7, som har som uppgift att se till att talspolen 1:1 anordnas axiellt. Anslutningsområdet mellan spolbärare 1:2, membran 2 och centreringsdon 7 limmas. Membranet 2 har i ytterkanten en fjädrande anordning som också har till uppgift att styra talspolen axiellt. 10 15 20 25 30 506 979 Den hittills beskrivna anordningen skulle nu kunna användas som en högtalare.Speech coil 1 and diaphragm 2 are now applied and glued with the projecting fastener 3 carrying the pre-magnetizable magnet 5, if present, and the first core part 6. The gluing takes place by means of a so-called controls the travel between the coil carrier 1: 2 and the first core part 6. The diaphragm 2 is then connected to the resilient centering 7, which has the task of ensuring that the voice coil 1: 1 is arranged axially. The connection area between coil carrier 1: 2, diaphragm 2 and centering device 7 is glued. The diaphragm 2 has at the outer edge a resilient device which also has the task of guiding the voice coil axially. 10 15 20 25 30 506 979 The device described so far could now be used as a loudspeaker.

För att få en effektivare högtalare anordnas emellertid ytterligare magnetdon 10, tex en neodymdisk, som kan förmagnetiseras i motfas gentemot det nämnda förmagnetiserade magnetdonet 5. Ytorna som är vända mot varandra har därvid samma polaritet och ett repellerande magnetfält bildas. Detta förmagnetiserbara magnetdon 10 är anslutet till en' andra kärndel 11 med ett hon-organ 11:1. Den övriga magnetiska kretsen består enligt utföringsformen av ett T-format"don 8 där den vertikala delens ände är vänd bakåt och utgör stöd för det förmagnetiserbara magnetdonet 10 och den andra kärndelen 11. Det T-formade donets horisontella del är fäst vid en hylsformad kåpas 9 främre ändkant 9:1. Den bakre ändkanten 9:2, som bildar en pol hos magnetsystemet, är avsedd att vid färdigmonterad högtalare anslutas till talspolens 1:1 periferi. Det andra fästdonet 8 och kåpan 9 kan även vara integrerat utformade. Mellan talspolen 1:1 och kåpan 9 måste ﬂnnas ett litet luftgap, t ex av storleksordningen en till två tiondels mm.In order to obtain a more efficient loudspeaker, however, additional magnetic devices 10 are provided, for example a neodymium disk, which can be pre-magnetized in opposite phase to the said pre-magnetized magnetic device 5. The surfaces facing each other thereby have the same polarity and a repelling magnetic field is formed. This pre-magnetizable magnet device 10 is connected to a second core part 11 with a female member 11: 1. According to the embodiment, the other magnetic circuit consists of a T-shaped device 8 where the end of the vertical part is turned backwards and forms a support for the pre-magnetizable magnetic device 10 and the second core part 11. The horizontal part of the T-shaped device is attached to a sleeve-shaped housing. 9 front end edge 9: 1 The rear end edge 9: 2, which forms a pole of the magnetic system, is intended to be connected to the 1: 1 periphery of the voice coil when the speaker is fully assembled.The second fastener 8 and the cover 9 can also be integrally designed. 1: 1 and the cover 9 must have a small air gap, for example of the order of one to two tenths of a mm.

På det förmagnetiserbara magnetdonet 10 limmas den andra kärndelen 11 innefat- tande ett hon-organet 11:1. I utföringsexemplet är hon-organet uformat som ett kon- format centrumhål 11:1. Centreringen och den axiella inriktningen som åstadkommes med de beskrivna delarna ger en noggrannhet av storleksordningen någon hundra- dels mm. Fästdon 8, kåpa 9 och kärndelar 6 och 11 kan tex vara av kolfattigt stål .The second core part 11 comprising a female member 11: 1 is glued to the pre-magnetizable magnetic device 10. In the exemplary embodiment, the female member is designed as a conformed center hole 11: 1. The centering and the axial alignment achieved with the described parts give an accuracy of the order of a few hundredths etc. Fasteners 8, cover 9 and core parts 6 and 11 can, for example, be made of low-carbon steel.

Kärndelarna 6 och 11 sammanfogas nu medelst limning och styres därvid axiellt med hjälp av tapp 6:1 och styrhål 11:1. Ett luftgap av någon tiondels mm måste därvid ﬁnnas mellan talspole och resp. magnetpoler.The core parts 6 and 11 are now joined together by gluing and are thereby guided axially by means of pin 6: 1 and guide holes 11: 1. An air gap of a few tenths of a mm must be created between the voice coil and resp. magnetic poles.

Om kärndelarna 6 och 11 ej haft sin tapp 6:1 och sitt styrhål 1121 skulle det varit svårt att med ett tillräckligt litet luftgap 12 (1 /10 mm) kunna montera en inverterad högtalare effektivt och med bra kvalitet, eftersom det finns en mycket stark magnetkraft i sidled och det därvid är mycket svårt att centrera magneterna. 506 979V Det är uppenbart för fackmannen att det ovan beskrivna utföringsexemplet endast är ett exempel och att de ingående delarna kan ha annan utformning och vara gjorda av andra material inom uppﬁnningens ram. Exempelvis behöver fästdonen ej vara T- formade, och magneter, talspoiedon, fästdon kan ha andra tvärsnitt, liksom även korg, membran, han- och honorgan osv. Likaså kan respektive fastsättningar göras med andra medel än limning.If the core parts 6 and 11 did not have their pin 6: 1 and their guide hole 1121, it would be difficult to mount an inverted speaker efficiently and with good quality with a sufficiently small air gap 12 (1/10 mm), since there is a very strong magnetic force laterally and it is very difficult to center the magnets. 506 979V It is obvious to the person skilled in the art that the embodiment described above is only an example and that the constituent parts may have a different design and be made of other materials within the scope of the invention. For example, the fasteners need not be T-shaped, and magnets, speech poets, fasteners may have other cross-sections, as well as baskets, membranes, male and female members, and so on. Likewise, the respective fastenings can be made by other means than gluing.

Claims

10 15 20 25 30 PÅTÜUISRÅY7 9

A method of mounting and centering speech coils (1), magnetic devices (5-6, 8-11) and diaphragms (2) in a basket (4) in an electromagnetic transducer for reproducing sound, characterized in that a first assembly is assembled, comprising: - said basket (4) with resilient centering means (7) arranged therein and a first fastening means (3), with, where appropriate, a pre-magnetized magnet means (5), and with a first core part (6) with male means (611) , said membrane (2) with a coil carrier (1: 2) arranged in its center hole which carries a speech coil (1: 1), the first assembly being completed by arranging the coil carrier (1: 2) on the first fastener (3) ; a second assembly is assembled, comprising: - a magnetic circuit consisting of a cover (9) with a second fastener (8) inside it, in which a pre-magnetizable magnet device (10) is applied with a second core part (11) arranged thereon with its -organ (11: 1); after which the two assemblies are joined by joining the two core parts (6, 11) and thereby aligning in the axial direction by means of the male and female members (6: 1, 11: 1).

An electromagnetic transducer for reproducing sound comprising: a first assembly comprising: - a basket (4) with resilient centering means (7) and a first fastener (3) arranged therein, and with a first core part (6), and a diaphragm (2) supporting in its center hole a coil carrier (1: 2) with a voice coil (1: 1), the coil carrier (112) being arranged on said first fastener (3); and a second assembly comprising: - a magnetic circuit consisting of a housing (9) with a second fastener (8) arranged therein, on which a pre-magnetizable magnetizer (10) is arranged, and on it a second core part (11), can characterized in that the core parts (6, 11) comprise male and female members (611, 11: 1) by means of which the core parts are axially aligned when they are joined together. 10 15 20 25 30 7 sus 9791

3. An electromagnetic transducer as claimed in Claim 2, characterized in that the male and female members consist of a pin (6: 1) resp. a guide hole (1111).

Electromagnetic transducer according to one of Claims 2 to 3, characterized in that a further pre-magnetized magnet (5) is arranged between the first fastener (3) and the first core part (6).

5. An electromagnetic transducer according to claim 4, characterized in that the pre-magnetized magnetic devices (5, 10) consist of neodymium disks and the like.

Electromagnetic transducer according to one of Claims 2 to 5, characterized in that the first fastener (3) consists of a T-shaped device fixed in the basket, the horizontal part of which is fastened under the basket and the vertical part of which extends up through the basket ( 4) and at the end carries the first core part (6).

Electromagnetic transducer according to one of Claims 2 to 6, characterized in that the second fastener (8) consists of a T-shaped device whose horizontal part is fastened to one end edge (911) of the housing (9) and whose vertical part extends into the basket (4) and at the end carries the other core part (11).

Electromagnetic transducer according to one of Claims 2 to 7, characterized in that the other end edge (9: 2) of the housing is arranged in connection with the voice coil (111) with an air gap therebetween.

Electromagnetic transducer according to one of Claims 2 to 8, characterized in that the second fastener (8) is integrated with the cover (9).

Electromagnetic transducer according to one of Claims 2 to 7, characterized in that the diaphragm (2) and the centering device (7) are connected to the coil carrier (1) at the same area.