Electrodynamic loudspeaker including a damping ring

Abstract

Electrodynamic loudspeaker comprising a damping ring. The electrodynamic loudspeaker (10) comprises: - a fixed chassis (12); - a motor (13) having a fixed base (14) connected to the fixed chassis (12) and an assembly (16) movable axially relative to the fixed base (14) along an axis of the loudspeaker (AA'); - a convex diaphragm (18); - a lattice (20) connecting the convex diaphragm (18) and the movable assembly (16). A peripheral edge (44) of the convex diaphragm (18) is mounted on the lattice (20), and the electrodynamic loudspeaker (10) further comprises a damping ring (70) connecting an internal radial portion (73) of the convex diaphragm (18) and the lattice (20). Figure for the abbreviation: Figure 1

Description

Title of the invention: Electrodynamic loudspeaker comprising a damping ring

[0001] The present invention relates to an electrodynamic loudspeaker comprising:

[0002] - a fixed chassis;

[0003] - an engine comprising a fixed base connected to the fixed chassis and a movable assembly axially relative to the fixed base along an axis of the loudspeaker;

[0004] - a convex membrane;

[0005] - a lattice connecting the convex membrane and the moving assembly.

[0006] In the design process of an electrodynamic loudspeaker, consideration of the natural vibration modes of the radiating surface is crucial. Indeed, these resonance modes are detrimental to the sound reproduction of a loudspeaker because they generate audible acoustic distortions. These distortion defects are all the more problematic when the loudspeaker aims for very high-end Hi-Fi (high fidelity) listening quality. Such a loudspeaker may, for example, exhibit a modal resonance in its radiating section that is too energetic relative to the required HiFi specifications.

[0007] Furthermore, for a very high-end loudspeaker, the specifications also require strong aesthetic considerations. More specifically, the loudspeaker's aesthetics are heavily influenced by the design of the loudspeaker dome, and this imposes significant constraints during the design of said loudspeaker.

[0008] One aim of the invention is therefore to propose an electrodynamic loudspeaker that improves the quality of sound reproduction while impacting the aesthetics of the loudspeaker as little as possible.

[0009] To this end, the invention relates to an electrodynamic loudspeaker of the aforementioned type, in which a peripheral edge of the convex membrane is mounted on the lattice and in which the electrodynamic loudspeaker further comprises a damping ring connecting an internal radial portion of the convex membrane and the lattice.

[0010] Thanks to the invention, and in particular thanks to the damping ring connecting the convex diaphragm and the moving assembly, the amplitude of a resonance mode of the convex diaphragm is reduced. Measurements show a decrease in the total harmonic distortion of the loudspeaker at certain problematic resonance peaks.

[0011] According to other advantageous aspects of the invention, the electrodynamic loudspeaker comprises one or more of the following features, taken individually or in all technically possible combinations:

[0012] - the damping ring has a section parallel to the upper axis- speaking a truncated conical shape flared from the lattice towards the convex membrane;

[0013] - the lattice comprises an inner ring and an outer ring centered on the axis of the loudspeaker as well as a plurality of radial pillars connecting the inner ring and the outer ring, the damping ring connecting the inner radial portion of the convex diaphragm and the inner ring of the lattice;

[0014] - the electrodynamic loudspeaker further comprises an elastic ring of guide extending in a plane substantially perpendicular to the axis of the loudspeaker and whose outer periphery is connected to the inner ring of the lattice and to the damping ring;

[0015] - the outer periphery of the elastic guide ring is wedged between the ring damping and the inner ring of the truss;

[0016] - the damping ring includes an annular groove extending opposite the inner ring of the lattice and accommodating the outer periphery of the elastic guide ring;

[0017] - the fixed chassis comprises an external radial part and an internal radial part, the internal radial part comprising an external peripheral edge, an internal periphery of the elastic guide ring being connected to the external peripheral edge of the internal radial part of the fixed frame;

[0018] - the trellis further comprises a fixing ring for at least a part of the moving assembly, in particular one end of a coil holder of the moving assembly, the fixing ring being centered on the axis of the loudspeaker and extending radially towards the axis of the loudspeaker from the inner ring of the lattice;

[0019] - the electrodynamic loudspeaker further comprises an elastic annular seal of suspension connecting the outer ring of the truss and the fixed frame, in particular the outer ring of the truss and an upper end of an outer circumferential wall of the fixed frame;

[0020] - the damping ring is made of a material having a density less than or equal to 60 kg / m3.

[0021] The invention will become clearer upon reading the following description, given solely by way of non-limiting example, and made with reference to the drawings in which:

[0022] [Fig-1] - [Fig.1] is a cross-sectional view of an electrodynamic loudspeaker according to the invention, according to a cutting plane passing through the axis of the loudspeaker;

[0023] [Fig.2] - [Fig.2] is an enlarged simplified schematic view of a portion of the loudspeaker of [Fig.1], illustrating a portion of the lattice, convex diaphragm, damping ring, fixed chassis, elastic guide ring and elastic suspension joint.

[0024] In what follows, the expressions "front", "in front", "rear", "behind" are to be understood in reference to the main direction of propagation of sounds from a loudspeaker.

[0025] A speaker direction DHP is also defined, directed from the rear to the front parallel to a speaker axis A-A'.

[0026] With reference to figures 1 and 2, an electrodynamic loudspeaker 10 according to the invention is described.

[0027] The loudspeaker 10 is advantageously substantially of revolution about the loudspeaker axis A-A'.

[0028] The loudspeaker 10 comprises a fixed chassis 12, a motor 13 comprising a fixed base 14 connected to the fixed chassis 12 and a movable assembly 16 axially movable, in particular along the loudspeaker axis A-A', relative to the fixed base 12.

[0029] The loudspeaker 10 also includes a convex diaphragm 18 and a lattice 20 connecting the convex diaphragm 18 and the moving assembly 16.

[0030] In addition, the loudspeaker 10 includes a damping ring 70 connecting the convex diaphragm 18 and the lattice 20.

[0031] Advantageously, the loudspeaker 10 further includes an elastic guide ring 76.

[0032] The fixed chassis 12 is also known as the "salad bowl". It comprises a base 28 and a circumferential wall 30 extending from the base 28 towards the front of the speaker 10.

[0033] Advantageously, the fixed chassis 12 comprises an external radial part 24 and an internal radial part 26.

[0034] In particular, the external radial part 24 of the fixed frame 12 carries the bottom 28 and the circumferential wall 30.

[0035] Advantageously, the external radial part 24 of the fixed frame 12 is axially behind the internal radial part 26 of the fixed frame 12.

[0036] Even more advantageously, the external radial part 24 of the fixed chassis 12 extends radially further from the axis of the loudspeaker A-A' than the internal radial part 26 of the fixed chassis 12.

[0037] In particular, the external radial part 24 of the fixed chassis 12 extends around the motor 13, in particular around the fixed base 14 of the motor 13.

[0038] Advantageously, the internal radial part 26 of the fixed chassis 12 extends into a space delimited by a fixing ring 52 of the trellis 20 in front of the motor 13.

[0039] The internal radial part 26 of the fixed chassis 12 includes an external peripheral edge 27 advantageously extending in a plane perpendicular to the axis of the loudspeaker A-A' in which also extends an internal ring 46 of the lattice 20.

[0040] Advantageously, the internal radial part 26 of the fixed chassis 12 further includes an internal peripheral edge 29 extending in particular in a plane perpendicular to the loudspeaker axis A-A' in which also extends an external ring 48 of the lattice 20.

[0041] Even more advantageously, the internal radial part 26 of the fixed frame 12 comprises a plurality of radial pillars 31 connecting the external peripheral edge 27 and the internal peripheral edge 29.

[0042] The radial pillars 31 are distributed angularly around the speaker axis A-A'. They each extend between the outer peripheral edge 27 and the inner peripheral edge 29.

[0043] The circumferential wall 30 has a frustoconical shape of the speaker axis A-A' flared towards the front of the speaker 10.

[0044] Advantageously, the circumferential wall 30 is formed by radial pillars 32 extending between the bottom 28 of the fixed frame 12 and an external peripheral edge 33 of the circumferential wall 30.

[0045] In the embodiment of the invention shown in the figures, the fixed base 14 comprises a yoke 34 on which a magnet 35 is disposed. The yoke 34 defines at least one air gap 36.

[0046] Advantageously, the fixed base 14 of the motor 13 further includes an annular support 38 centered on the speaker axis A-A' and arranged in an internal space delimited by the cylinder head 34 to define the air gap 36 with the cylinder head 34.

[0047] Even more advantageously, the magnet 35 has an annular shape and is arranged along the speaker direction A-A' in front of the breech 34, in particular between the breech 34 and the annular support 38.

[0048] The moving assembly 16 includes a cylindrical coil holder 41 along the speaker axis A-A' on the outer surface of which an excitation coil 42 is wound.

[0049] The excitation coil 42 is disposed in the air gap 36.

[0050] The excitation coil 42 is capable of oscillating about the loudspeaker axis A-A' around an equilibrium position shown in the figures.

[0051] In the description that follows, the "axial" direction means the direction along the loudspeaker axis A-A', and the "radial" direction means a direction perpendicular to the axis A-A'.

[0052] The convex membrane 18 defines an acoustic radiation surface of the loudspeaker 10.

[0053] Advantageously, the convex membrane 18 has a convexity oriented towards the front of the loudspeaker 10.

[0054] In particular, the convex membrane 18 has a spherical cap or dome shape.

[0055] The convex membrane 18 has a peripheral edge 44.

[0056] In particular, the peripheral edge 44 has a substantially circular shape centered on the speaker axis A-A'.

[0057] The peripheral edge 44 of the convex membrane 18 is mounted on the lattice 20, in particular on the outer ring 48 of the lattice.

[0058] With reference to figures 1 and 2, the lattice 20 is generally with axis A-A'.

[0059] The lattice 20 is in particular a structural part intended to stiffen the moving assembly 16 and to allow the attachment of suspensions.

[0060] The lattice 20 comprises the inner ring 46, the outer ring 48, and a plurality of radial pillars 50 connecting the inner ring 46 and the outer ring 48.

[0061] The trellis 20 further includes the fixing ring 52. The fixing ring 52 is intended for fixing one end 53 of the spool holder 4L

[0062] The inner and outer rings 46, 48 are coaxial.

[0063] The outer ring 48 has a larger diameter than the inner ring 46.

[0064] Axially, the outer ring 48 is behind the inner ring 46.

[0065] The outer ring 48 is directly fixed to the peripheral edge 44 of the convex membrane 18.

[0066] The radial pillars 50 are distributed angularly around the speaker axis A-A'. They each extend between the outer ring 48 and the fixing ring 52.

[0067] The fixing ring 52 is centered on the axis of the loudspeaker A-A' and extends radially towards the axis of the loudspeaker A-A' relative to the inner ring 46 of the lattice 20.

[0068] The fixing ring 52 has a diameter smaller than that of the inner ring 46.

[0069] Axially, the fixing crown 52 is arranged behind the inner ring 46 and in front of the outer ring 48.

[0070] The mounting ring 52 includes a receiving groove 58 into which the end 53 of the spool holder 41 of the moving assembly 16 is received. The receiving groove 58 is advantageously bonded to the spool holder 4L

[0071] The loudspeaker 10 further includes an elastic suspension joint 64.

[0072] The elastic suspension joint 64 connects the outer ring 48 of the lattice 20 and the fixed chassis 12. In particular, the elastic suspension joint 64 connects an upper end of the circumferential wall 30 of the fixed chassis 12 to the outer ring 48.

[0073] The elastic suspension joint 64 is arranged axially behind the outer ring 48.

[0074] The elastic suspension joint 64 extends around the axis A-A'. It extends in a radial plane. The elastic suspension joint 64 has, in cross-section along a plane passing through the axis A-A', a Q shape, the convexity of Q being axially turned towards the rear of the loudspeaker 10.

[0075] The elastic suspension joint 64 is airtight.

[0076] The damping ring 70 connects an internal radial portion 73 of the convex membrane 18 and the lattice 20. The internal radial portion 73 is arranged between the center of the convex membrane 18 and the peripheral edge 44 of the convex membrane 18. For example, the internal radial portion 73 is an annular portion of the convex membrane 18 centered on the axis A-A'.

[0077] In particular, the damping ring 70 connects the internal radial portion 73 of the convex membrane 18 and the internal ring 46 of the lattice 20. The internal radial portion 73 of the convex membrane 18 is then arranged opposite the internal ring 46 of the lattice 20.

[0078] Advantageously, the damping ring 70 is compressed between the lattice 20 and the convex membrane 18, in particular between the internal radial portion 73 of the convex membrane 18 and the internal ring 46 of the lattice 20.

[0079] Even more advantageously, the damping ring 70 is glued onto the lattice 20 and / or the convex membrane 18.

[0080] Advantageously, radially with respect to the loudspeaker axis A-A', the internal radial portion 73 of the convex diaphragm 18 is arranged further from the loudspeaker axis A-A' than is the voice coil carrier 4L

[0081] As can be seen in figures 1 and 2, the damping ring 70 has, in a section parallel to the axis of the loudspeaker A-A', a flared truncated conical shape from the lattice 20 towards the convex membrane 18, in other words in the direction of the loudspeaker DHP.

[0082] Advantageously, the damping ring 70 includes an annular groove 72 extending opposite the inner ring 46 of the trellis 20 and intended to accommodate an outer periphery 78 of the elastic guide ring 76.

[0083] Even more advantageously, the damping ring 70 is made of a damping material having a density less than or equal to 60 kg / m3.

[0084] For example, the damping material is an expanded polymer material, in particular with closed or open cells, or a foam.

[0085] In particular, the damping material is a thermoplastic polymer, such as ethylene-vinyl acetate.

[0086] The elastic guide ring 76 is commonly known by the English name "spider".

[0087] The elastic guide ring 76 extends in a plane substantially perpendicular to the axis of the loudspeaker A-A' and in particular around the axis of the loudspeaker A-A'.

[0088] The elastic guide ring 76 has the outer periphery 78.

[0089] The outer periphery 78 of the elastic guide ring 76 is connected to the inner ring 46 of the truss 20 and to the damping ring 70.

[0090] In particular, the outer periphery 78 of the elastic guide ring 76 is wedged between the damping ring 70 and the inner ring 46 of the lattice 20, in particular in the annular groove 72 of the damping ring 70.

[0091] Advantageously, the elastic guide ring 76 further has an internal periphery 80.

[0092] The inner periphery 80 of the elastic guide ring 76 is connected to the outer peripheral edge 27 of the inner radial part 26 of the fixed frame 14.

[0093] Thanks to the invention described above, a reduction in the total harmonic distortion of the loudspeaker was observed at a problematic resonance peak located in particular at 280 Hz. This reduction decreases the amplitude of the total harmonic distortion peak by approximately 1 dB.

[0094] The use of the damping material for the damping ring 70 makes it possible to reduce acoustic defects and improve the sound reproduction of the loudspeaker while allowing the loudspeaker 10 to withstand significant mechanical stresses, high temperatures and internal mechanical stresses.

[0095] The damping material is in particular lightweight, stiff and has a high loss factor which allows modal energy dissipation by mechanical damping.

[0096] The fact that the damping ring 70 is compressed between the lattice 20 and the convex membrane 18 allows the resonance modal energy of the convex membrane 18 to be transmitted to the lattice 20 and to the moving assembly 16 through the damping ring 70 which has a high damping coefficient.

Claims

Demands

1. Electrodynamic loudspeaker (10) comprising: - a fixed chassis (12); - a motor (13) having a fixed base (14) connected to the fixed chassis (12) and an assembly (16) movable axially relative to the fixed base (14) along an axis of the loudspeaker (A-A'); - a convex diaphragm (18); - a truss (20) connecting the convex diaphragm (18) and the movable assembly (16); characterized in that a peripheral edge (44) of the convex diaphragm (18) is mounted on the truss (20) and in that the electrodynamic loudspeaker (10) further comprises a damping ring (70) connecting an internal radial portion (73) of the convex diaphragm (18) and the truss (20).

2. Electrodynamic loudspeaker (10) according to claim 1, wherein the damping ring (70) has, in a section parallel to the axis of the loudspeaker (A-A'), a truncated conical shape flared from the lattice (20) towards the convex diaphragm (18).

3. Electrodynamic loudspeaker (10) according to claim 1 or 2, wherein the lattice (20) comprises an inner ring (46) and an outer ring (48) centered on the axis of the loudspeaker (A-A') and a plurality of radial pillars (50) connecting the inner ring (46) and the outer ring (48), the damping ring (70) connecting the inner radial portion (73) of the convex membrane (18) and the inner ring (46) of the lattice (20).

4. Electrodynamic loudspeaker (10) according to claim 3, wherein the electrodynamic loudspeaker (10) further comprises an elastic guide ring (76) extending in a plane substantially perpendicular to the axis of the loudspeaker (A-A') and of which an outer periphery (78) is connected to the inner ring (46) of the lattice (20) and to the damping ring (70).

5. Electrodynamic loudspeaker (10) according to claim 4, wherein the outer periphery (78) of the elastic guide ring (76) is wedged between the damping ring (70) and the inner ring (46) of the lattice (20).

6. Electrodynamic loudspeaker (10) according to claim 4 or 5, wherein the damping ring (70) comprises a groove annular (72) extending opposite the inner ring (46) of the lattice (20) and accommodating the outer periphery (78) of the elastic guide ring (76).

7. Electrodynamic loudspeaker (10) according to any one of claims 4 to 6, wherein the fixed chassis (12) comprises an external radial portion (24) and an internal radial portion (26), the internal radial portion (26) comprising an external peripheral edge (27), an internal periphery (80) of the elastic guide ring (76) being connected to the external peripheral edge (27) of the internal radial portion (26) of the fixed chassis (12).

8. Electrodynamic loudspeaker (10) according to any one of claims 3 to 7, wherein the lattice (20) further comprises a retaining ring (52) for at least a part of the moving assembly (16), in particular one end (53) of a coil holder (41) of the moving assembly (16), the retaining ring (52) being centered on the axis of the loudspeaker (A-A') and extending radially towards the axis of the loudspeaker (A-A') from the inner ring (46) of the lattice (20).

9. Electrodynamic loudspeaker (10) according to any one of claims 3 to 8, wherein the electrodynamic loudspeaker (10) further comprises an elastic suspension annular joint (64) connecting the outer ring (48) of the lattice (20) and the fixed chassis (12), in particular the outer ring (48) of the lattice (20) and an upper end of an outer circumferential wall (30) of the fixed chassis (12).

10. Electrodynamic loudspeaker (10) according to any one of the preceding claims, wherein the damping ring (70) is made of a material having a density less than or equal to 60 kg / m3.

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