DE3036149C2 - Electroacoustic converter with vibration generators that oscillate against each other - Google Patents

Description

The invention relates to an electroacoustic transducer according to the preamble of the patent claims. 1.

A larger membrane area with a central vibration drive, the same at all points To transmit phase position, as is well known, includes extensive compromise solutions, especially if a comprehensive audio frequency spectrum is to be broadcast.

Stabilize the membranes by folding them several times or by putting two of the same kind against each other Cones with their bases to make them vibrate as a whole, however, is with increasing inertia limited and can only incompletely with regard to the occurring problem of partial oscillations be solved.

Typical designs for this are DE-PS 5 98 145 and DE PS 5 48 807. The further characteristics of such Membranes, the radiation characteristic is not clear, because the effective membrane parts are out of phase opposing compensating membrane parts and the bending moments that occur.

Efforts were therefore made to divide the membrane area into several individual membranes and to separate them with

J5 th vibration generators or via rods, polygons with the use of holding threads, Drive support elements from a central drive system, as has recently been the case with the DE-AS 26 49 771 was made known.

As a result, apart from a not inconsiderable expense, these systems for a Omnidirectional radiation are less suitable and only obey limited frequency segments, which means that they are assigned to corresponding crossovers.

Electroacoustic transducers with flexible, non-developable membrane bodies are also known, see above inter alia also with spherical and olive-shaped membrane bodies, see under GB-PS 3 12 666 and

so DE-OS 26 07 858, which see the subject of the invention outwardly similar, but not the idea of the invention have underlying characteristics.

In the case of the objects listed, which are generally referred to as flexural vibrators, the force vectors are directed against each other at the equatorial area of the closed membrane body.

The same also applies to vibration generators acting on one side of the membrane body, the known from DE-AS 27 09 374, where the one-sided mounting of the membrane body as a static counterforce also occurs in a compensating manner at the equatorial range and the division of the frequency range into different membrane sizes cannot be eliminated.

In addition, the bending forces that are stored and released again require additional damping means to counteract nonlinear distortion.

In connection with this, US Pat. No. 3,424,873 should be noted here, in which a triple in frequency ranges subdivided closed steep cone in bending helix L> n radiates radially and for effective bass reproduction in a conventional manner on a resonance box must vibrate axially.

Proceeding from this, DE OS 25 28 482 became known, instead of the resonance box, to complete the diaphragm cone with a second opposing cone oscillating against one another in order to convert dL axially directed vibrations of the diaphragm surfaces into radial deflections, similar to the above-mentioned explanations.

Here too, however, the radiation remains in the range of a low level of efficiency, since it only is achieved by deforming and bending the membrane structure.

In contrast, the invention is based on the object of providing a coherent sound image without frequency subdivision and emit only from a membrane consisting of at least two identical individual elements to leave, whereby the deficiencies indicated so far are largely eliminated.

The solution to this problem arises from the features of the characterizing part of the patent application 2 "> Proverbs 1.

A membrane body made up of several individual elements, the membrane elements with one another connected by folds is known per se. The invention also shows this feature in one Embodiment, however, differs significantly from the previously known principles.

The peculiarity of the invention is based essentially in the two-part division of the membrane, which as Buckling diaphragm can be grasped and each of which part of the diaphragm, made rigid, by one separate vibration generator is driven.

Since the vibrations are transmitted to the membrane elements in their longitudinal direction, can only sound pressure generating membrane deflections through the interaction of both membrane elements at their opposing contact edges, namely at the kink where the Diaphragm speed is greatest.

The membrane elements are under a 4> obtuse angles to each other and are rounded at their edges, causing mutual rolling achieved during the oscillation process, especially with large amplitudes, without the occurrence of bending forces will.

The embodiment according to the invention therefore requires deflection in a diaphragm which generates sound pressure when it is deflected no use of polygons, holding threads and membrane bending or other membrane folds.

In contrast to conventional, known electro-dynamic transducer, where the transmitting direction of oscillation takes place substantially in the direction of the diaphragm displacement and transverse waves and propagation delays can not be neglected, t> o obtained by the inventive embodiment has the advantage that the stability of the membrane elements undesirable in their longitudinal direction Transverse and longitudinal waves and thus transit time delays are eliminated, since the transmitted vibration component ^{b5 is} also located in the longitudinal direction of the membrane elements.

As a result, high frequencies in the area of the greatest membrane velocity are also amplified Radiation brought and crossovers or the division of the membrane system into different Frequency ranges dispensable. In addition, the mutually vibrating membrane elements act counter-coupling.

The invention enables both flat membranes on baffles as well as all-round radiating membranes to be carried out, whereby the latter is allowed a larger misalignment in the drive direction, since the annular gap magnets commonly known in loudspeaker construction can be used here with advantage and closed housing shapes and baffles are out of the question.

Flat diaphragms require special magnet constructions for the drive, which have an incorrect angle of the transmitting Exclude vibration components in the longitudinal direction on the membrane element.

With regard to the required stability and the applied membrane stage, the membrane elements are in their length generally to 150 bi: 200 mm limited, but the width can be freely selected.

In the case of large radiation areas, it is advisable to shift the width extension vertically. Possibly can also use limited membrane systems in a large number of side by side at any angle and arranged vertically, depending on the required radiation characteristics.

For example, if all-round radiation is desired, there are several, but at least three, such buckled membrane systems arranged in a circle, the long sides of which are folded together in the known manner softer, if possible anechoic. Material, are connected and so are two pyramid-shaped adjoining Form membrane cones. The z. B. on pressure in their axial directions spreading of their membrane elements experience and thus a radial deflection at the equatorial area.

Depending on the voice coil diameter, the membrane elements must be suitably trapezoidal Cut to be given.

The voice coil is connected directly to the membrane body or, in the case of smaller voice coils, via a connecting cone. But the energy share of each surface element is compelling, also with regard to the longitudinal stability and the low frequency range so that the voice coil does not fall below a certain minimum diameter allowed.

The amount of energy transmitted is favorable with a straight conductor, because the angle of error the drive oscillation direction is equal to zero, based on the entire membrane surface up to the effect of both Vibration components on the contact edges of the membrane elements. With further training of the Invention, the driving current conductor is not separated, but directly on the membrane element or attached within the same.

The question of negative feedback can easily be solved in a converter according to the invention. So in the area of greatest speed in the resulting vibration direction, namely at the opposing membrane edges, a dynamic receiver is also attached, its voltages for negative feedback in the amplifier can be applied.

The starting material for the membrane elements is hard, corrugated aluminum sheet Composite with softer fabrics, whereby the membrane surface from the ground up with an inner cushioning

has sufficient longitudinal stability.

The invention is described in more detail below with the aid of some exemplary embodiments shown in the drawing explained. It shows

F i g. 1 schematically shows the active components of the two membrane elements with dynamic vibration generators;

Fig. 2 is a perspective sectional partial view one according to the FIG. 1 trained oscillating system; F i g. 3 is a front view of a surface radiator;

4 schematically shows a magnet arrangement for membrane elements with an applied conductor and their holding in the magnetic field;

5 shows a membrane element with an applied conductor for surface radiators;

6 shows two trapezoidal membrane elements connected by folds for membrane bodies radiating all around;

7 shows a view of a membrane body which radiates all around and is made up of several trapezoidal cut-outs Membrane elements with two dynamic annular gap magnets and connecting cones for the Adaptation to smaller voice coils (1 cone shown in section).

The surface radiator F i g. 3 consists of the frame (14), the Faltendichtungcn (15) and the kink diaphragm (13) with the drive systems (1 and Xa).

The drive systems are composed of the magnetic poles (8) and the magnetic rods (9). the Current conductors are located on the U-shaped bent part (TO) that is supported by the suspension (11) and is connected to the membrane element (13) at (10).

The frame is advantageously designed as a load-bearing structure and is very long repeated cross stiffening. For the attachment of the drive systems there are following angle constructions to choose.

If the converter is not to be used as a dipole radiator, the frame must be closed on one side and nadi the usual methods of closed boxes.

The F i g. 5 shows an embodiment where the current conductor (17) is applied directly to the membrane element (18). That has the disadvantage of being a bit more complex Magnet construction, as can easily be seen from Fig. 4, the pivot point position (16) is still over relocated the end of the membrane element so that the drive oscillation direction is always in the longitudinal direction of the membrane element remains and even parts of the membrane oscillating in opposite phase cannot occur.

A major advantage, however, is that a simple adjustment is made at the pivot point position (16) can be used to maintain the symmetry of the two opposing vibration components necessary is.

The Fi g. 7 shows an all-round radiator made of several trapezoidal membrane elements (29). These are, as can be seen from Fig. 6, by folding (19) on their Long sides connected to one another. The folds are made of elastic anechoic material.

The two completely identically formed cones have elastic at their reinforced edges (20 in FIG. 6) Glue connected (30 in Fig. 7). This is also possible from FIG. 2 at 12 also clearly emerged.

The adaptation to smaller voice coils takes place via the cones (28 in Fig. 7) to which the Adjusting disks (26), which are corrugated and made of plastic, are attached.

If the voice coil is large enough, the membrane cones are directly connected to the voice coils.

The cage-like housing is symmetrical and is through the cover plates (22) and (23) with the five connecting columns (21) in FIG. 7 formed.

The two annular gap magnets (24) are connected to the plates (23).

The axially adjustable pins (25) lead through the magnets (24) to the adjusting disks (26) and are used in the Especially for regulating the tension in the two conical diaphragms and for adjusting the symmetry the mutually axially directed vibration components of both voice coil drives.

In summary, the invention is a broadband system, which in its structure allows great variation in the radiation characteristics. The importance of the invention lies especially in the fact that the electroacoustic transducer neither crossovers nor a division of the Membrane body in different frequency ranges require.

For this purpose 2 sheets of drawings

Claims (5)

Patent claims: 1. Electroacoustic transducer for sound reproduction with two mutually oscillating, symmetrically arranged electrodynamic vibration generators, between which there are at least two non-flexing membrane elements in the same line of symmetry to the vibration generators, characterized in that the vibrations of an electrodynamic vibration generator (1) are essentially not one flexible, rigid membrane element (2) stiffened by longitudinal grooves, preferably quadrangular, are transferred from one edge (3) in the longitudinal direction (4) and that the opposite edge (5) is a second identical membrane element {2a) at an obtuse angle "Alpha" of not greater than 160 degrees, which is also opposite in the longitudinal direction (4a) the vibrations of a second vibration generator {la) are transmitted, which is arranged symmetrically opposite the first, so that only from the interaction of the two vibration components a sound pressure-generating deflection of the membrane elements results, the resulting oscillation direction (6) at the opposing surface edges of the membrane elements (5 and 5a) is always perpendicular to the axis of symmetry (7) of the two oscillation generators (1 and Xa) if they are operated to oscillate with equal intensity , and that the opposing surface edges (5 and 5a) are reinforced (by 20) and rounded so that they can roll against each other when vibrating, especially large amplitudes, and that these edges are attached to the membrane sides of the angle they enclose by elastic adhesive "Alpha" are held. 2. Electroacoustic transducer according to claim 1, characterized in that the current conductor (17 in Fig. 5) is attached at the end on the membrane element or within the same and that the The pivot point position (16) is outside the membrane element and the adjustment is made there can be used to maintain the symmetry of the two opposing vibration components necessary is. 3. Electroacoustic transducer according to claim 1, characterized in that the membrane elements (Fig.6) run essentially oblong trapezoidal and that several, but at least three pairs of membrane elements each forming a buckling membrane arranged in a circle are, the membrane elements with their conical sides by elastic folds (19) made of soft, in particular anechoic material, are connected and thus two identical pyramid-shaped Form mutually vibrating membrane cones, which are preferably generated by vibration generators operated with annular gap magnets (24) (Fig. 7). 4. Electroacoustic transducer according to claim 3, characterized in that a wavy adjusting disk (26) is located inside the membrane body and is secured by an adjustable pin (25) the pre-tensioning regulation of the conical diaphragms and the adjustment of the symmetry of the against each other axially directed vibration components of both Voice coil drives made possible 5. Electroacoustic transducer according to one of claims 3 or 4, characterized in that to adapt to smaller voice coil diameters (27) on the diaphragm cone Connecting cone (28) are located.