CN115696146A

CN115696146A - Loudspeaker and corresponding mounting method, and loudspeaker box integrated with loudspeaker

Info

Publication number: CN115696146A
Application number: CN202210894902.9A
Authority: CN
Inventors: 路易斯·贾利特; 马克思·雷内; 赫迪·阿贝斯
Original assignee: Devialet SA
Current assignee: Devialet SA
Priority date: 2021-07-28
Filing date: 2022-07-27
Publication date: 2023-02-03
Also published as: FR3125910B1; FR3125910A1; EP4125085B1; EP4125085A1

Abstract

The present application relates to a loudspeaker and a corresponding mounting method, as well as to a loudspeaker enclosure integrated with such a loudspeaker. The speaker includes: a magnetic circuit defining at least one gap; and a mobile device. The mobile device includes: a coil holder, a coil located within the gap, a membrane for transmitting sound waves, and a connection system connecting the membrane with the coil holder. The membrane is reversibly movable relative to the connection system between an installed position, in which the membrane is coupled to the connection system, and a removed position, in which the membrane is decoupled from the connection system. In the mounted position the membrane forms a shield between the exterior of the loudspeaker and the magnetic circuit.

Description

Loudspeaker and corresponding mounting method, and loudspeaker box integrated with loudspeaker

Technical Field

The invention relates to a loudspeaker of the type comprising:

-a magnetic circuit defining at least one gap; and

-a movable device for vibrating along an axis of the loudspeaker relative to the magnetic circuit, the movable device comprising a coil holder, a coil fixed on the coil holder and located in the gap, a membrane for emitting sound waves, the membrane defining a front side of the loudspeaker along the axis, and a connection system connecting the membrane with said coil holder.

The invention also relates to a sound box integrated with the loudspeaker and a method corresponding to the loudspeaker.

Background

The woofer is used to play sound waves with a frequency below 1000 hz, preferably below 500 hz, even more preferably below 150 hz. In the case of external mounting, the woofer is usually fixed to the internal structure of the enclosure of the loudspeaker box by means of fixing screws which pass axially through the magnetic circuit and whose heads are located on one side of the membrane.

The known mobile device as a whole exhibits a mass M suspended on a spring with stiffness K (raideur) and has a resonance frequency f obtained by the following formula:

wherein: f is frequency in hertz (Hz);

m is the mass of the mobile device in kilograms (kg); and

k is the suspension stiffness (raideur des subspensions) in newton meters (N/m).

Likewise, each of the parts of the moving equipment and other parts subject to cyclic stresses has an inherent mass and stiffness that imparts a resonant frequency to each part, which is given by a formula similar to the above. It is important that the K/M ratio of each part is not too low, for example higher than 450 hz, preferably higher than 1500 hz, even more preferably higher than 5000 hz, since the stiffness is sufficiently large and the mass is not too large. Otherwise, the frequency of use of the loudspeaker may result in a new resonance frequency, which will result in a distortion of the sound waves emitted by the membrane.

It is also important that the membrane should be firmly fixed to the connection system to avoid poor contact, which can increase the vibrations that interfere with the acoustic signal of the membrane.

Thus, to meet these constraints, the membrane is first glued to the connection system and then the mobile device is connected to the rest of the loudspeaker by means of one or more flexible suspensions.

Then, after the speaker is completed, the speaker is fixed to, for example, the housing. The speaker/enclosure assembly is then secured to the internal structure 22 by means of set screws (or other securing means). The membrane defines a central opening that allows a screwdriver to be used to insert the set screw from the exterior of the speaker and enclosure. After the speaker is secured, a cover is placed over the speaker to cover the opening defined by the membrane.

This manufacturing method is satisfactory from an acoustic point of view. In addition, the cover may center the movable portion of the speaker with the motor (moteur) when the speaker is manufactured. However, the opening defined by the membrane that allows the fixing screws to be placed should eventually be covered by the cover, which may spoil the continuous and smooth appearance of the enclosure and is often unsightly in the eyes of the user.

Disclosure of Invention

It is therefore an object of the present invention to provide a loudspeaker which is more continuous and smooth in construction, making the loudspeaker more aesthetically pleasing to the user, while still being easy to mount on the enclosure of the cabinet.

To this end, the invention provides a loudspeaker of the above-mentioned type, wherein:

the membrane is reversibly movable with respect to the connection system between an installation position, in which the membrane is coupled to the connection system, and a removal position, in which the membrane is decoupled from the connection system; and

in the mounted position, the membrane forms a shield between the exterior of the loudspeaker and the magnetic circuit.

According to a particular embodiment, the speaker comprises one or more of the following characteristics, obtained individually or in all technically possible combinations:

the membrane comprises a threaded portion for screwing into or onto the connection system along an axis and at the mounting position;

-at the mounting position, the membrane and the connection system are tightened with a tightening torque greater than or equal to 0.05 nm about the axis;

the connection system comprises an end piece defining an external thread around an axis, the external thread being configured to cooperate with the threaded portion of the membrane;

the end piece defines an annular groove, the loudspeaker comprising a sealing gasket housed in the groove and radially compressed between the end piece and the threaded portion of the membrane in the mounted position;

the membrane comprises a central portion forming a dome, the dome being axially directed towards the outside of the loudspeaker in the mounted position, the end piece preferably forming a protrusion which axially abuts on a peripheral portion of the central portion in the mounted position;

-thin-film ratchet-type fixation (encliquite) in or on the connection system;

the film is made of plastic material, such as acrylonitrile butadiene styrene, and comprises an inner surface preferably defining radial edges.

The present invention also provides a sound box, comprising:

-a housing;

-at least one loudspeaker as described above; and

a fixing system for selectively fixing the loudspeaker to the housing, the fixing system passing through the magnetic circuit and being accessible from the front side of the loudspeaker when the membrane is in the detached position.

The invention also relates to a method for mounting a loudspeaker as described above, comprising the steps of:

-fixing the loudspeaker to the housing by means of a fixing system accessible from the front side of the loudspeaker, the membrane being in the detached position; and

-reversibly moving the membrane from the detached position to the installed position.

Drawings

The invention will be better understood from reading the following description, given by way of example only and made with reference to the accompanying drawings. In the drawings:

FIG. 1 is a schematic cross-sectional view of an acoustic enclosure according to the present invention with the membrane in a disassembled position;

FIG. 2 is a cross-sectional view of a loudspeaker similar to the enclosure shown in FIG. 1 with the membrane in an installed position according to the present invention;

fig. 3 is a detailed view of the speaker shown in fig. 2 centered on the threaded portion of the membrane.

Detailed Description

Referring to fig. 1, an acoustic enclosure 10 according to the present invention is illustrated.

The sound box 10 includes: a housing 12 defining an opening 14, a speaker 16 extending through the opening 14 and defining an axis D, and a securing system 18 for securing the speaker to the housing.

According to a variant not shown, the enclosure 10 comprises one or more other loudspeakers. These speakers are advantageously speakers similar to the speaker 16 and placed head-to-tail (t e b e) with the speaker 16.

In the example shown, the housing 12 includes an outer shell 20 defining the opening 14, and an inner structure 22. The internal structure 22 is attached to the outer shell 20 or, as a variant, is formed integrally with the outer shell.

The loudspeaker 16 is for example a woofer as defined hereinbefore.

Here, the internal configuration of the speaker 16 will be described with reference to the illustration in fig. 1, and particularly, with reference to the examples of fig. 2 and 3.

The speaker 16 is generally centered about an axis D, except as specifically noted below.

The loudspeaker 16 comprises a frame 24, a magnetic circuit 26 defining a gap 28, and a movable device for vibrating along the axis D relative to the magnetic circuit.

Advantageously, the loudspeaker 16 also comprises two

suspensions

32, 34.

In the example shown, suspension 32 is a flexible washer (joint cushion) connecting mobile device 30 to frame 24.

The flexible gasket 32 has a U-shaped cross-section, for example along a radial half plane P (fig. 2).

Also in the illustrated example, the suspension 34 is a corrugated or pleated washer (also known by the trade name of spider), for example, to couple the mobile device 30 to the frame 24.

The active device 30 includes a coil holder (port-box) 36 and a coil 38. The coil 38 is fixed to the coil holder and is located in the gap 28. The mobile device comprises a membrane 40 for emitting acoustic waves, and a connection system 42 rigidly connecting the membrane to the coil holder 36. The membrane defines the front side of the loudspeaker along axis D.

The coil holder 36 is, for example, cylindrical.

The membrane 40 is reversibly movable between an installed position (as shown in fig. 2) and a removed position (as shown in fig. 1). In the installed position, the membrane is coupled to the connection system 42. In the detached position, the membrane is detached from the attachment system. In the mounted position, the membrane 40 forms a shield between the exterior of the loudspeaker and the magnetic circuit 26.

The term "forming a shield" means that the membrane at the mounting position prevents the magnetic circuit from entering from the front of the loudspeaker.

Film 40 is advantageously made of a plastic material, such as ABS (acrylonitrile butadiene styrene).

In the installed position, the membrane is screwed onto the connection system 42. Advantageously, the film and the connection system are tightened with a tightening torque around the axis D greater than or equal to 0.05 nm, preferably greater than or equal to 0.5 nm, and more preferably up to 4 nm or even 9 nm.

According to a variant not shown, the membrane has an external thread and is screwed into the connection system.

According to another variant, not shown, the membrane is not screwed, but fixed in or on the connection system in a ratchet-type manner.

The film includes a central portion 44, a threaded portion 46, and advantageously a plurality of ribs 50.

The diameter of the film in a direction perpendicular to the axis D is D1. In the mounted position, the pressure exerted by the membrane and the connection system 42 on each other has a resultant axial force R.

The central portion 44 forms, for example, a dome pointing axially forwards at the mounting location of the membrane. The central portion 44 includes a front surface 52, which is advantageously smooth, and a rear surface 54 that carries the ribs 50.

The central portion 44 forms, for example, a partial sphere.

Advantageously, the central portion 44 is free of any openings.

As shown in fig. 3, the threaded portion 46 extends axially rearward from, for example, an edge 56 of the central portion 44. The threaded portion 46 has, for example, a substantially cylindrical shape with respect to the axis D, forming a skirt at the periphery of the central portion 44.

The thickness of the threaded portion 46 is, for example, substantially equal to the thickness of the central portion 44 and is advantageously between 0.2 and 8 millimeters (mm).

Threaded portion 46 forms threads 58 on a radially inner side for mating with connection system 42.

The thread 58 forms, for example, a single turn of a helix about the axis D.

As a variant, the thread 58 comprises a plurality of mutually different spirals.

The ribs 50 advantageously extend radially, preferably from a ring 60 centred on the axis D.

The rib 50 has an axial extension E which is advantageously maximum at the ring 60 and decreases with distance from the axis D.

The axial thickness E becomes zero in the peripheral region 60 of the rear surface 54.

In a section along radial half-plane P, connection system 42 comprises a radially inner end piece 62 fixed to coil holder 36, and a radially outer end piece 64 defining an external thread 66 encircling axis D. External threads 66 are configured to mate with threaded portion 46 of the membrane. The connection system 42 includes a first plurality of links 68 extending radially between the

end pieces

62 and 64, and advantageously includes a second plurality of links 70 extending axially rearward from the end pieces 64 or alternatively from the links 68.

The end piece 62 for example surrounds the axis D. The end piece 62 advantageously defines an aperture 72, and the coil retainer 66 is received in the aperture 72.

The links 70 are advantageously distributed discretely about the axis D. The links 70 each include an end 74 to which the suspension 34 is secured.

The links 68 are advantageously distributed discretely about the axis D. Each link 68 includes, for example, a base portion 76 connecting the

end pieces

62 and 64, and a radially extending reinforcement link 78.

The end piece 64 includes a lower surface 80. Suspension 32 is secured to lower surface 80. The U-shaped base of the hanger bracket faces axially rearward.

End member 64 defines an annular recess 82. The groove 82 receives a sealing gasket 84. The sealing gasket 84 is radially compressed between the end piece 64 and the threaded portion 46 of the membrane in the installed position.

The end piece 64 forms, for example, a boss 86. The projection 86 axially abuts against a peripheral portion 88 of the central portion 44 of the membrane.

The peripheral portion 88 is located radially between the interrupted portion 60 of the tie bar 50 and the edge 56 of the membrane.

In the mounted position of the membrane, the projection 86 exerts a pressure on the membrane, the resultant axial force R1 of which is shown in fig. 3.

The threads 66 of the end piece 64 exert a pressure on the threads 58 of the membrane, the resultant axial force R2 of which is shown in fig. 3.

The fixing system 18 is, for example, a screw 90 housed in an axial groove 92, the axial groove 92 passing through the magnetic motor 26.

When the membrane 40 is in the detached position and detached, the screw head 92 is accessible from the outside of the loudspeaker 16 via a groove 94, the groove 94 being defined by the coil holder 36 and the connection system 42 and being open axially forward.

The method of mounting the enclosure 10 is explained herein.

At a first time, the loudspeaker 16 is assembled without the membrane 40, i.e. with the membrane 40 in the disassembled position. Throughout this stage, the recess 94 is accessible from outside the speaker, which helps to center the coil holder 36 and the connection system 42 relative to the magnetic circuit 26.

At a second time, the speaker 16, having no membrane 40 at all times, is placed through the opening 14 against the internal structure 22 of the housing 12. The loudspeaker 16 without membrane is then fixed to the housing by means of the fixing system 18, i.e. by screwing the screws 90 into the housing. This screwing operation is performed by acting on the head 92 of the screw by means of a tool (not shown) entering the recess 94 from the outside of the enclosure.

Finally, the membrane is reversibly moved from the detached position to the attached position. In the example shown, membrane 40 is screwed onto connection system 42.

Tightening is performed until the desired tightening torque about axis D is achieved.

The membrane 40 and the connecting system 42 then exert the already mentioned pressure on each other. The axial resultant of the pressure exerted on the membrane by the lobes 86 of the end piece 64 of the connection system is R1. The resultant axial force of the pressure exerted by the membrane on the protrusions is opposite to R1.

The resultant axial force of the pressure exerted by the threads 66 of the end piece 64 on the threads 58 of the threaded portion 46 of the membrane is R2. The resultant axial force of the pressure exerted by threads 58, in turn, on threads 66 is opposite to R2.

Due to the above features, the membrane 40 is assembled at the end and there is no need to define an opening for the entry of the fastening system 18. Thus, in the mounted position, the membrane forms a shield between the exterior of the loudspeaker 16 and the magnetic circuit 26. Thus, the cover plate is not required, and the speaker has a more continuous and smooth appearance than the related art.

The membrane 40 is reversibly mounted and therefore easily disassembled without risk of damaging the speaker 16. Nevertheless, the value of the tightening torque is advantageously such as to prevent the user from easily removing the film 40.

The assembly of the membrane 40 on the rest of the mobile device 30 advantageously does not require any glue and allows to achieve the required rigidity.

The removal of the membrane 40 is quick, easy and economical if subsequent maintenance operations are required.

Claims

1. A loudspeaker (16) comprising:

a magnetic circuit (26) defining at least one gap (28); and

-a movable device (30) for vibrating relative to the magnetic circuit (26) along an axis (D) of the loudspeaker (16), the movable device (30) comprising a coil holder (36), a coil (38) fixed on the coil holder (36) and located within the gap (28), a membrane (40) for emitting sound waves, and a connection system (42) connecting the membrane (40) with the coil holder (36), the membrane (40) defining a front side of the loudspeaker (16) along the axis (D);

the method is characterized in that:

said membrane (40) being reversibly movable with respect to said connection system (42) between an installation position, in which said membrane (40) is coupled to said connection system (42), and a removal position, in which said membrane (40) is detached from said connection system (42); and

in the mounted position, the membrane (40) forms a shield between the exterior of the loudspeaker (16) and the magnetic circuit (26).

2. A loudspeaker (16) as set forth in claim 1 wherein said membrane (40) includes a threaded portion (46), said threaded portion (46) for screwing into or onto said connection system (42) along said axis (D) and at said mounting location.

3. Loudspeaker (16) according to claim 2, wherein, in the mounted position, the membrane (40) and the connection system (42) are tightened with a tightening torque greater than or equal to 0.05 nm about the axis (D).

4. A loudspeaker (16) as set forth in claim 2 or 3 wherein said connection system (42) includes an end piece (64), said end piece (64) defining an external thread (66) about said axis (D), said external thread (66) configured to mate with a threaded portion (46) of said membrane (40).

5. A loudspeaker (16) as set forth in claim 4 wherein said end piece (64) defines an annular groove (82), said loudspeaker (16) including a sealing gasket (84), said sealing gasket (84) being received in said groove (82) and being radially compressed between said end piece (64) and said threaded portion (46) of said membrane (40) in said installed position.

6. Loudspeaker (16) according to claim 4 or 5, wherein the membrane (40) comprises a central portion (44), the central portion (44) forming a dome, which dome is axially directed outside the loudspeaker (16) in the mounted position, the end piece (64) preferably forming a protrusion (86), which protrusion (86) axially abuts on an outer peripheral portion (88) of the central portion (44) in the mounted position.

7. Loudspeaker (16) according to claim 1 to 6, wherein the membrane (40) is fixed in or on the connection system (42) in a ratchet-like manner.

8. Loudspeaker (16) according to any of claims 1 to 7, wherein the membrane (40) is made of a plastic material, such as acrylonitrile butadiene styrene, and comprises an inner surface (54) preferably defining radial ribs (50).

9. An acoustic enclosure (10), comprising:

a housing (12);

at least one loudspeaker (16) according to any one of claims 1 to 8; and

a securing system (18) for selectively securing the speaker (16) to the housing (12), the securing system (18) passing through the magnetic circuit (26) and being accessible from a front side of the speaker (16) when the membrane (40) is in the detached position.

10. A method of mounting an acoustic enclosure (10) according to claim 9, comprising the steps of:

-fixing the loudspeaker (16) on the housing (12) by means of the fixing system (18), the fixing system (18) being accessible from the front side of the loudspeaker (16), the membrane (40) being in the detached position; and

reversibly moving the membrane (40) from the detached position to the installed position.