EP0685981B1 - Loudspeaker - Google Patents

Abstract

The loudspeaker membrane (11) is made of metal, to allow it to be secured to the metal coil carrier (10) for the loudspeaker coil via ultrasonic welding, with an intermediate insulation device (16) fitted between the facing planar surfaces of the coil carrier and the loudspeaker membrane. The insulation device has outer metal layers (19.1, 19.2) which are suitable for ultrasonic welding to the coil carrier and the loudspeaker membrane respectively, on either side of an intermediate insulator (18). <IMAGE>

Description

Technical field

The invention is concerned with the formation of high temperature resistant Connections of loudspeaker components, in particular with the connection of loudspeaker membranes with voice coil carriers.

State of the art

Loudspeaker membranes and voice coil carriers for loudspeakers are according to the state of the art, unless they are be formed in one piece, connected to each other by gluing. For example, it is known, one made of aluminum formed voice coil former with an adhesive a loudspeaker membrane made of plastic, metal or paper connect to. The requirements that a such adhesive connection are also available known. Such a connection should be easy, both Fabrics - even under thermal influence - firmly together connect and also be easy and quick to train.

For loudspeakers with an aluminum voice coil former and a speaker membrane made of plastic, metal or Have paper, these requirements are up to operating temperatures satisfactorily solved up to 120 ° C. Become speakers exposed to higher ambient temperatures, the Temperature resistance of the bond is rapidly decreasing. Measures like such as the use of improved adhesives a slightly higher temperature resistance, but require adhesives, their use from an environmental point of view today is no longer justifiable.

The problems just discussed also arise when the Voice coil former or the loudspeaker membrane with a so-called Centering membrane is connected by adhesive.

One-piece construction of voice coil former and loudspeaker membrane plastic can only partially solve the problems solve, because these materials in the desired temperature range do not have the necessary strength.

One-piece metal structures of voice coil former and Speaker diaphragm cannot currently match the one you want Properties can be manufactured inexpensively, in particular it is not possible to use an aluminum speaker membrane or titanium together with the voice coil former in about one To train deep-drawing processes.

From EP-A-0 251 057 it is known for a loudspeaker to make the bead, the membrane and the basket from plastic and by ultrasonic welding or heat sealing with each other connect to. Through these measures, manufacturing of the speaker simplified, its efficiency increased and the distortion factor is reduced, however, the welded hold Compounds of higher temperatures from about 120 ° C no longer was standing.

In US-A-5,027,412 is a coil for a loudspeaker described, the wire ends with an electrically conductive Foil ultrasonically welded instead of soldered to the electrical Make connection stable for higher temperatures.

The invention has for its object a speaker specify where the various components of the speaker, especially voice coil former and loudspeaker membrane and, if provided, also a centering membrane that is environmentally compatible are connected to each other up to over 120 ° C, and which is nevertheless inexpensive to manufacture.

Presentation of the invention

A first solution to this problem is given by the features Claim 1 rendered.

A second solution to this problem is according to the features Claim 2 rendered.

Advantageous further developments of the invention are the Claims 3 to 7 removable.

If, according to claim 1, the components of the loudspeaker to be connected are provided with an ultrasonically weldable metal, at least on their mutually facing and intended surfaces, then the respective components of the loudspeaker can be connected to one another very easily using ultrasonic welding technology, provided the thickness of the respective metal layer is greater than about 8 µm . The connection is particularly simple when the components to be connected are made entirely of ultrasonically weldable metal, since in this case there is no need to coat the surface areas provided for the connection.

The connection can be made in welding technology between the voice coil former and the loudspeaker membrane, between the voice coil former and the centering membrane and between the loudspeaker diaphragm and the centering diaphragm alike run well. But this does not mean that only such connections between loudspeaker components in ultrasonic welding technology can be trained where it depends on a lower weight of the connection. Much more can also be the connection between the centering membrane and the loudspeaker basket is designed as an ultrasonic weld his.

According to the invention is according to claim 2 Voice coil former with the loudspeaker membrane or the centering membrane with the voice coil former or with the loudspeaker membrane with the interposition of an insulating arrangement connected, the insulator on two opposite surface areas with an ultrasonically weldable material is coated. Is the insulation arrangement between the Voice coil carrier and the speaker membrane arranged so is used for loudspeaker membranes subject to high thermal loads the insulator conducts heat from the speaker diaphragm to Voice coil former difficult, so that to isolate the the voice coil wire arranged none special measures need to be taken. Is the Isolation arrangement on one side with the loudspeaker membrane or the voice coil former and on the other side connected to a centering membrane made of metal, can the centering membrane if, for example, from two or several parts not connected to each other is, as a contact bridge between the ends of the voice coil wire and the ends of the audio signal feed line.

Ceramic or polyimide materials have proven to be suitable insulation materials proven. Such substances are suitable Material thicknesses can be coated with aluminum or copper, for example.

Particularly good ultrasonic weldability of the centering membrane is given when the metal coating of the Centering membrane is designed as specified in claim 6 is.

Centering membranes and / or centering membranes made of non-metal, that have no mesh structure and therefore are of unbroken design with the first components of the loudspeaker can be connected when the connection provided edge has the border specified in claim 7.

Brief presentation of the figures

Figur 1:

eine Schnittdarstellung durch einen Schwingspulenträger;

Figur 2:

eine weitere Darstellung gemäß Figur 1;

Figur 3:

eine weitere Darstellung gemäß Figur 1;

Figur 4:

eine weitere Darstellung gemäß Figur 1; und

Figur 5:

vier weitere Darstellungen gemäß Figur 3.

Show it:

Figure 1:

a sectional view through a voice coil former;

Figure 2:

a further representation according to Figure 1;

Figure 3:

a further representation according to Figure 1;

Figure 4:

a further representation according to Figure 1; and

Figure 5:

four further representations according to FIG. 3.

Ways of Carrying Out the Invention

FIG. 1 shows a section through a loudspeaker in a detail, with the representations to the right and left of the center line have different embodiments to the subject.

The left representation according to FIG. 1 shows a voice coil former 10, which at its top with the speaker membrane 11 is connected. The loudspeaker diaphragm 11 and the voice coil former 10 are formed from aluminum, so that the surface areas in contact with each other 13.1 and 13.2 of the loudspeaker membrane 11 and the voice coil former 10 are made of materials that are ultrasonically welded are. The loudspeaker diaphragm 11, which in the here discussed connection area the first component of the speaker represents within the meaning of claim 1, with Voice coil former 10, which is a second component in the sense of claim 1 is ultrasonically welded.

Furthermore, the cone region 14 of the loudspeaker diaphragm 11 is included the centering membrane 15 connected, being between the speaker membrane 11 and the centering membrane 15 an insulating arrangement 16 is arranged, on which in connection with Figure 2 is discussed in more detail.

In this context it should be pointed out that when the centering diaphragm 15 with the loudspeaker diaphragm 11 is connected, a two-part formation of a metal Centering membrane formed as a contact bridge between the Wire ends of those arranged on the voice coil former 10 Voice coil 17 and the wire ends of the audio signal feed line (Everything not shown in Figure 1) can be used. In In this case you can use an otherwise usual wire contact the voice coil 17 with the audio signal line is dispensed with become.

The right representation according to FIG. 1 differs from the left representation in that the insulating arrangement 16 not between the centering diaphragm 15 and the loudspeaker diaphragm 11, but between the speaker membrane 11 and the voice coil bobbin 10 is arranged. This arrangement has the advantage that the arrangement of the insulating arrangement 16 between the loudspeaker membrane 11 and the voice coil former 10 the heat conduction from the loudspeaker membrane 11 to the voice coil former 10 or to the voice coil 17 is more difficult is.

In this context it should be noted that the isolation arrangement 16 also between the centering membrane 15 and the Loudspeaker diaphragm 11 and between the loudspeaker diaphragm 11 and the voice coil former 10 can be provided, with which the advantages of the two individual representations according to FIG. 1 are united with each other.

An insulating arrangement 16 is shown enlarged in FIG. This insulation arrangement 16 is of a position one Isolators 18 formed, which in the exemplary embodiment discussed here is made of ceramic material. This isolation arrangement 16, which is a second component of the speaker is within the meaning of claim 2, on the side of the Isolators 18, which the first component of the speaker - here the voice coil former 10 - faces a metal coating 19.1, which in the present case is made of Kufper is. The surface area 13.2 of the metal coating 19.1 is with the surface area 13.1 formed of aluminum Voice coil former 10 using the ultrasonic welding technique connected.

On the side facing away from the metal coating 19.1 Insulator 18 is another one also made of copper Metal coating 19.2 available, which does not match the metal coating 19.1 is conductively connected.

The surface area 13.3 of the metal coating is 19.2 with the surface area 13.4 of that made of aluminum Speaker membrane 11 also ultrasonically welded.

Each of the two metal coatings 19.1 and 19.2 has a thickness of 8 8 μm , while the thickness of the insulation layer 18 is approximately 1 mm.

The feasibility of the invention is not based on use of copper as metal for the metal coatings 19.1 and 19.2 limited. Rather, the respective metal coating can be made of aluminum or nickel. Good results are also used with a polyimide film as insulator 18 achieved, which to form an insulating arrangement 16 on both sides is coated with aluminum.

The isolator arrangement 18 shown in FIG. 2 essentially shows the installation situation according to the illustration on the right Figure 1. Should the centering membrane 15 with the speaker membrane 11 not be conductively connected (left illustration according to Figure 1), the insulating arrangement 16 according to Figure 2 is also in usable in this embodiment. In this case it is Loudspeaker diaphragm 11 is the first component of the loudspeaker in The meaning of claim 2, while the insulating arrangement 16 the second component of the loudspeaker within the meaning of claim 2 is.

Figure 3 shows a further representation of a loudspeaker in the Cut. The first component of the speaker in mind of claim 1, the voice coil former 10, while the loudspeaker diaphragm 11 is the second component of the loudspeaker represents within the meaning of claim 1.

Both components 10 and 11 just mentioned are made of aluminum manufactured and ultrasonically welded together.

If there is thermal insulation between the two components 10 and 11 should be necessary, can also be in the connection area an insulating arrangement 16 according to Figure 2 between the components 10 and 11 may be provided (not shown in Figure 3).

In a departure from the representations according to FIG Figure 3 arrangement shown a centering membrane 15, which is connected to the voice coil former 10. Here too can if necessary between the centering membrane 15 and the Voice coil former an insulating arrangement 16 according to Figure 2 be arranged (not shown in Figure 3). The dashed Representation of the centering membrane 15 in Figure 3 makes clearly that the centering membrane 15 is also completely eliminated can, if the centering of the voice coil bobbin 10 also in another way - as shown in DE-A-42 41 212 - executed is. More details on connecting one in figure 3 shown centering membrane 15 with the voice coil bobbin 10 or with the speaker membrane 11 is related are explained in more detail with FIG.

Figure 4 shows a connection of the voice coil bobbin 10 with the loudspeaker diaphragm 11, the illustrations on the right and left of the center line different embodiments affect.

The voice coil former 10 and the loudspeaker membrane 11 are made of aluminum in the two exemplary embodiments and without an intervening isolation arrangement 16 connected to each other by ultrasonic welding.

In contrast to the representation according to Figure 1 is in the right 4, the voice coil former 10 is longer trained and thus projects lower with its upper end 20 into the cone formed by the loudspeaker membrane 11. At the upper end 20 of the voice coil bobbin 10 is one closing the inner cross section of the voice coil bobbin 10 and also cup-shaped made of aluminum Cap 21 inserted and connected. The weldability the cap 21 with the voice coil former 10 in ultrasonic welding technology to ensure it is essential that the edge 22 of the cap 21, over which this with the Inner jacket of the voice coil bobbin 10 is connected in the Direction points that the voice coil 17 facing away. The latter This is because after the cap 21 has been put on with the Edge 22 down that of the cap 21 and the voice coil former 10 limited space for welding electrodes no longer is accessible.

The left side of the illustration according to FIG. 4 shows one Dust cap 21, which is also made of aluminum and is shaped like a dome. This dust cap 21 is with its circumferential flange 23 with the inside the speaker diaphragm 11 by ultrasonic welding connected.

According to FIG. 3, a centering membrane 15 is present and with the voice coil bobbin 10 or the loudspeaker membrane 11 connected, such a connection according to the state of the Technology generally carried out as an adhesive connection. In view of the temperature problems associated with such adhesive bonds at higher ambient temperatures is now in Connection with Figure 5, a connection between the centering membrane 15 and the voice coil former 10 or the loudspeaker membrane 11 indicated which the temperature problems solves. Are the latter two components 10 and 11 with their respective surface areas 13 or completely made of an ultrasonically weldable metal, so the centering membrane 15 with these components 10 and 11 very easily connected in ultrasonic welding if at least the surface areas 13 of the centering membrane 15, which with the respective component 10 or 11th are connected, also from an ultrasonically weldable Are made of metal. Since centering membranes 15 are conventional are designed as textile or plastic mesh the producibility of an ultrasonically weldable coating on such materials very expensive and only realizable with considerable effort. However, is used as a material for the centering membrane 15 metal or a metal braid used, this material can be applied by using galvanic process very easily with another ultrasonic weldable Metal, for example with the metal of the voice coil bobbin 10 are coated. Although such a galvanic coating with good adhesion of the centering membrane 15 can be produced are coating processes of this type not harmless for reasons of environmental protection. It is therefore much more advantageous the connection of centering membrane 15 and ultrasonically weldable Execute metal coating as follows is performed.

Since conventionally designed centering membranes 15 are corrugated Show contour, it is common to this contour by execution of an embossing step. In this step of embossing a thin and made of ultrasonically weldable metal existing strip inserted into the embossing tool, flows through or penetrates the metal of the strip Braid the centering membrane 15 under the pressure of the embossing tool. When this process is complete, it is a condition reached, which is illustrated schematically in Figure 5a. This representation clearly shows that after the Embossing the centering membrane 15 the area of the strip 24, which faces the centering membrane 15, the braid openings 25 penetrates in the centering membrane 15. Penetrate Areas of the strip 24 the braid openings 25 in the centering membrane 15 is a connection between the two Given parts 15 and 24, which allows both parts as Unity. Should one of the two parts 15 and 24 formed unit with the voice coil former 10 or Speaker membrane 11 are ultrasonically welded, it is essential that the centering membrane 15 with the surface side on the voice coil bobbin 10 or on the loudspeaker membrane 11 is applied, which faces away from the strip 24. This is because the areas of the strip 24 that the Pass through braid openings 25, not yet suitable on their own are; the centering membrane 15 under mechanical stress permanently, for example with the voice coil bobbin 10 connect. The desired high mechanical strength between the centering membrane 15 and the voice coil bobbin 10 or the speaker diaphragm 11 is only reached when the centering membrane 15 between the strip 24 and the Voice coil carrier 10 and the loudspeaker membrane 11 are anodized and the areas of the strip 24 which are the braid openings 25 penetrate with the voice coil former 10 or the speaker membrane 11 ultrasonically welded are. The latter is in Figure 5b for a connection between the speaker diaphragm 11 and the centering diaphragm 15 schematically shown.

A particularly stable attachment between the centering membrane 15 and the respective component 10 or 11 of the speaker can be carried out if the centering membrane is embossed 15 the strip 24 inserted into the tool is softened by means of ultrasound. This softening can also after connecting the centering membrane 15 to the strip 24 be carried out after the embossing step. In both Cases permeates with the appropriate design of the tool or the ultrasonic welding arrangement the metal of the Strip 24 the braid openings 25 such that also on the side of the centering membrane facing away from the strip 24 15 forms a consistently thin metal film 26. The latter is shown schematically in Figure 5c. Because the metal film 26 and the remaining strip 24 have approximately the same thickness, it is for welding to the speaker diaphragm 11 or the voice coil bobbin 10 regardless of whether the metal film 26 or the strip 24 is used.

The discussed in connection with Figures 5a to 5c Centering membrane 15 is, for example, a steel wire mesh educated. The thickness of the wire is approximately 0.1 mm. The Centering membrane 15 can also be made of a non-metal his. When using non-metallic materials the procedure should be modified so that no Strip is used, which is pressed through the braid openings becomes. Instead, the one made from a non-metallic Material formed centering membranes 15 the edge the centering diaphragm 15, which for connection to the speaker diaphragm 11 or the voice coil former 10 connected should be of an approximately U-shaped edging 27 made of ultrasonically weldable metal. The latter is shown in Figure 5d. The one shown in Figure 5d Bezel 27 is formed by an L-shaped elbow is bent around the edge 28 of the centering membrane 15, so that after bending two legs 29 and 30 of the U-shaped Pinch the edge 28. Are the surfaces the border 27, which abut the centering membrane 15, roughened or with projections (not shown) provided after bending into the centering membrane 15 penetrate is a stable connection of the border 27 created with the centering membrane 15. For additional Solidification of the connection can be made together with the skirt 27 with the centering membrane 15 also with a step-shaped embossing beads (not shown) his.

In this context, it should also be pointed out that when using the bezel 27, the centering membrane 15 not necessarily formed from a broken mesh have to be. Also, the bezel 27 is not on centering membranes 15 limited from non-metal, but can also at Centering membranes 15 made of metal can be used.

The connection between the one provided with a border 27 Centering membrane 15 and, for example, the speaker membrane 11 is realized such that the leg 30 of the border 27 on an anvil 31 serving as counterelectrode is launched. The sonotrode 32 is then used for welding placed on the inside 33 of the speaker diaphragm 11 so that the speaker membrane 11, the legs 29 and 30 of the border 27 and the edge 28 against the anvil 31 be pressed. In this state, the ultrasonic welding executed, the leg 29 connects the Border 27 with the loudspeaker diaphragm 11 used centering membrane 15 made of an openwork mesh formed, the metal of the bezel 27 penetrates the Braid openings 25 (not shown in Figure 5d) and connects so the two legs 29 and 30 through the centering membrane 15 through.

Although those discussed in connection with Figures 5a to 5d Embodiments only the connection between the centering membrane 15 and the speaker membrane 11 and the Voice coil bobbin 10 can affect those shown there Measures also for the connection between the centering membrane 15 and the speaker basket (not shown) can be used.

Claims (7)

1. A loudspeaker, having a loudspeaker diaphragm (11) and having a voice coil support (10),
   characterised in that

   at least one surface region (13.1) of a first component of the loudspeaker and at least one surface region (13.2) of a second component of the loudspeaker are made from metals which can be connected to one another by ultrasonic welding,

   and in that

   the first and second components can be ultrasonically welded to one another by their respective surface regions (13.1, 13.2),

   in that

   the first component of the loudspeaker is either the voice coil support (10) or the loudspeaker diaphragm (11),

   in that

   the second component of the loudspeaker is either the voice coil support (10) or a centring diaphragm (15),

   and in that

   the respective first component is connected to a second component of the loudspeaker that has another name.
2. A loudspeaker having a loudspeaker diaphragm (11) and having a voice coil support (10),
   characterised in that

   at least one surface region (13.1) of a first component of the loudspeaker and at least one surface region (13.2) of a second component of the loudspeaker are made from metals which can be connected to one another by ultrasonic welding,

   and in that

   the first and the second components can be ultrasonically welded to one another by their respective surface regions (13.1, 13.2),

   in that

   the first component of the loudspeaker is the voice coil support (10) or the loudspeaker diaphragm (11),

   in that

   the second component of the loudspeaker is an insulating system (16), which in each case is formed from a layer of an insulator (18), and which comprises another metal coating (19.2) that can also be ultrasonically welded at the side faced away from the metal-coated surface region (13.2),

   and in that the metal coating (19.2) of the respective insulator (18) is connected by ultrasonic welding with a surface region (13.4), also made from a metal that can be ultrasonically welded, of a loudspeaker part which is different from the respective first component.
3. A loudspeaker according to Claim 1,
   characterised in that at least the first component of the loudspeaker is made completely of a metal that can be ultrasonically welded.
4. A loudspeaker according to Claim 2,
   characterised in that the insulating system (16) comprises a ceramic layer as the insulator (18).
5. A loudspeaker according to Claim 2,
   characterised in that the insulating system (16) comprises a polyimide layer as the insulator (18).
6. A loudspeaker according to Claim 1,
   characterised in that, if the second component is the centring diaphragm (15), the region of the centring diaphragm (15) which is intended for connection with a first component (10, 11) of the loudspeaker comprises a metal layer that can be ultrasonically welded, which lies at least on one surface side of the centring diaphragm (15) and penetrates mesh apertures (25) provided in the centring diaphragm (15).
7. A loudspeaker according to Claim 1,
   characterised in that, if the second component is the centring diaphragm (15), the region of the centring diaphragm (15) which is intended for connection with the first component (10, 11) of the loudspeaker comprises a border (27) made of metal that can be ultrasonically welded, which sheathes the edge of the centring diaphragm (15).

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