CN201134925Y

CN201134925Y - Electromagnetic loudspeaker

Info

Publication number: CN201134925Y
Application number: CNU2007201963914U
Authority: CN
Inventors: 郭英俊
Original assignee: AAC Acoustic Technologies Changzhou Co Ltd
Current assignee: AAC Technologies Holdings Changzhou Co Ltd
Priority date: 2007-12-24
Filing date: 2007-12-24
Publication date: 2008-10-15
Anticipated expiration: 2017-12-24

Abstract

An electromagnetic loudspeaker comprises a first coil, a second coil, a magnetic bowl, a first pole piece and a second pole piece which are all held in the magnetic bowl, a first magnetic steel between the first pole piece and the second pole piece, and a second magnetic steel between the second pole piece and the magnetic bowl, wherein a magnet gap is formed among the magnetic bowl, the first magnetic steel and the second magnetic steel, the first coil and the second coil are held in the magnet gap, and the polarities of the first magnetic steel and the second magnetic steel are arranged in the opposite directions, the winding directions of the first coil and the second coil are opposite, and the center position of the first coil is higher than the center position of the fist pole piece, and the center position of the second coil is slightly lower than the center position of the second pole piece.

Description

Magnetic speaker

[technical field]

The utility model relates to a kind of magnetic speaker, relates in particular to a kind of electromagnetic driving system of magnetic speaker.

[background technology]

Loud speaker is widely used in the various electronic equipments, to reach the effect of sounding.Along with the continuous lifting of loudspeaker applications environment requirement, the requirement of the reduction effect of sound is also being promoted.

Please join Fig. 1, be depicted as a kind of cutaway view of the loud speaker relevant with the utility model magnetic speaker.This loud speaker 90 comprises shell 91, the magnetic bowl 93 that supports by the vibrating diaphragm 92 of shell 91 support fixation, by shell 91, be housed in the permanent magnet 94 in the magnetic bowl 93 and cover pole piece 95 on the permanent magnet 94, shell 91, vibrating diaphragm 92, magnetic bowl 93, permanent magnet 94, pole piece 95 are essentially annular, permanent magnet 94 is variant with the radial width of magnetic bowl 93, between forms magnetic gap, vibrating diaphragm 92 connects the coil 96 of an annular, and coil 96 is placed in the magnetic gap.

Coil 96 is accepted the signal of telecommunication from external circuit, is subjected to (along B-B direction among the figure) motion about the effect of electromagnetic force in magnetic gap, and then drives vibrating diaphragm 92 up-down vibration, thereby produce sound.

Yet, the loud speaker that this correlation technique discloses, the distribution of magnetic field intensity and inhomogeneous in the magnetic gap between permanent magnet 94 and the magnetic bowl 93, the magnetic field intensity in pole piece 95 thickness ranges is stronger usually, and the magnetic field intensity outside pole piece 95 thickness ranges reduces (non-linear reducing) rapidly.After coil 96 receives external electric signal, will leave the equilbrium position, along with coil 96 away from or near in the thickness range process of pole piece 95, the electromagnetic force size is changing, away from the time vibration force reduce, near the time vibration force increase.In vibration processes, the vibration force instability causes vibrating diaphragm 92 vibration unstable, and then causes the sound instability sent, the nonlinear distortion of Here it is loud speaker.

Therefore the real loud speaker that is necessary to provide a kind of improvement reduces nonlinear distortion.

[utility model content]

The purpose of this utility model is to provide a kind of magnetic speaker that reduces nonlinear distortion.

The purpose of this utility model is achieved in that

A kind of magnetic speaker, it comprises first coil, second coil, the magnetic bowl, be contained in first pole piece in the magnetic bowl, second pole piece, first magnet steel between first pole piece and second pole piece, second magnet steel between second pole piece and magnetic bowl, form magnetic gap between the magnetic bowl and first magnet steel and second magnet steel, first coil and second coil are housed in this magnetic gap, the pole reversal setting of first magnet steel and second magnet steel, first coil and second coil around to opposite, and the center of first coil is higher than the center of first pole piece, and the center of second coil is lower than the center of second pole piece.

As a kind of improvement of the utility model magnetic speaker, the thickness of first magnet steel is higher than the thickness of second magnet steel.

Another kind as the utility model magnetic speaker improves, and the number of turn of first coil and length are greater than the number of turn and the length of second coil.

Compared with prior art, the utlity model has following advantage: the center of first coil is higher than the center of first pole piece, the center of second coil is lower than the centre bit of second pole piece, and the change of electromagnetic force trend that makes two coils be subjected to offsets, and stablizes the vibrating diaphragm vibration force.

[description of drawings]

Fig. 1 is the cutaway view of the loud speaker relevant with the utility model.

Fig. 2 is the cutaway view of the utility model magnetic speaker.

Fig. 3 is the cutaway view of the electromagnetic driving system of the utility model magnetic speaker.

[embodiment]

Describe the concrete structure of the utility model magnetic speaker in detail below in conjunction with accompanying drawing.

Please join Fig. 2, the vibrating diaphragm 12 that the utility model magnetic speaker 10 comprises shell 11, supported by shell 11, the magnetic bowl 13 that is supported by shell 11, be connected and form the lower cover 14 of product cavity with shell 11.In the bowl chamber of magnetic bowl 13, be disposed with first pole piece 15, first magnet steel 16, second pole piece 17 and second magnet steel, 18, the second magnet steel, 18 butt magnetic bowls 13.Magnetic bowl 13, first pole piece 15, first magnet steel 16, second pole piece 17 and second magnet steel 18 all are annular, and magnetic bowl 13 is accommodated first pole piece 15, first magnet steel 16, second pole piece 17 and second magnet steel 18 within it, in addition, magnetic bowl 13 forms magnetic gap diametrically and between first pole piece 15, first magnet steel 16, second pole piece 17 and second magnet steel 18.Vibrating diaphragm 12 below connecting coil groups 19, along radially above-mentioned, coil groups 19 is positioned in the magnetic gap.After coil groups 19 receives external electric signal, will be because the effect in magnetic field be stressed in magnetic gap.

Coil groups 19 comprises the skeleton 19a that is connected in vibrating diaphragm 12 and is wrapped in the first coil 19b and the second coil 19c on the skeleton 19a.The first coil 19b and the second coil 19c around to opposite, that is, and the outside signal of telecommunication in the first coil 19b and the second coil 19c to flow to direction opposite.

Vibrating diaphragm 12, coil groups 19, magnetic bowl 13, first pole piece 15, first magnet steel 16, second pole piece 17 and second magnet steel 18 are the electromagnetic driving system of magnetic speaker 10.

Please in the lump with reference to Fig. 3, first pole piece 15, first magnet steel 16, second pole piece 17 and second magnet steel 18 need be arranged in the following manner: first pole piece 15, first magnet steel 16, second pole piece 17 and second magnet steel 18 are disposed in order according to description, and first magnet steel 16 is opposite with the polarity of second magnet steel 18, i.e. the arrangement of N-S-S-N.Be eager to excel outside the magnetic field intensity relative thickness scope in first pole piece 15 and second pole piece, 17 thickness ranges.

During the equilbrium position, the first coil 19b is near first pole piece 15, and the center C 1 of the first coil 19b is higher than the center C 2 of first pole piece 15, and both differences in height are a; The second coil 19c is near second pole piece 17, and the center C 3 of the second coil 19c is lower than the center C 4 of second pole piece 17, and both differences in height are b.

After coil groups 19 receives external electric signal, the first coil 19b and the second coil 19c are because around to opposite, the sense of current in it is also opposite, simultaneously, because first magnet steel 16 is opposite with the polarity of second magnet steel 18, the first coil 19b is also opposite with the magnetic direction of the second coil 19c present position, therefore, the suffered electromagnetic force direction of the first coil 19b and the second coil 19c is consistent in fact, thereby drives vibrating diaphragm 12 vibration sounding on the A-A direction.

When coil groups 19 moves upward, the first coil 19b is away from the thickness range of first pole piece 15, suffered electromagnetic force reduces because of weakening of magnetic field intensity, the second coil 19c is near the thickness range of second pole piece 17, it is big that suffered electromagnetic force becomes because of the increase of magnetic field intensity, and the vibration force variation tendency of the vibration force variation tendency of the first coil 19b and the second coil 19c offsets;

When coil groups 19 moves downward, the first coil 19b is near the thickness range of first pole piece 15, suffered electromagnetic force becomes big because of the increase of magnetic field intensity, the second coil 19c is away from the thickness range of second pole piece 17, suffered electromagnetic force diminishes because of weakening of magnetic field intensity, and the vibration force variation tendency of the vibration force variation tendency of the first coil 19b and the second coil 19c offsets.

Therefore, in vibrating diaphragm 12 vibration processes, nonlinear change can take place in the vibration force of single coil, and is stable but the vibration force of coil groups but can keep, thereby reduces even eliminated nonlinear distortion.

In general, the magnetic field intensity of the magnetic gap between second pole piece 17, second magnet steel 18 and the magnetic bowl 13 is higher than the magnetic field intensity of the magnetic gap between first pole piece 15 and first magnet steel 16, for optimizing the electromagnetic force of the first coil 19b and the second coil 19c more, need suitably to increase the magnetic field intensity of the magnetic gap between first pole piece 15 and first magnet steel 16, feasible way is to make the thickness of the thickness of the magnet steel 16 of winning greater than second magnet steel 18, so that the stressing conditions of two coils is basic identical.

In order more to optimize the electromagnetic force of the first coil 19b and the second coil 19c, can make the number of turn of the first coil 19b and length the number of turn and length greater than the second coil 19c.

The above only is a better embodiment of the present utility model; protection range of the present utility model does not exceed with above-mentioned execution mode; as long as the equivalence that those of ordinary skills do according to the utility model institute disclosure is modified or changed, all should include in the protection range of putting down in writing in claims.

Claims

1, a kind of magnetic speaker, it comprises first coil, second coil, the magnetic bowl, be contained in first pole piece in the magnetic bowl, second pole piece, first magnet steel between first pole piece and second pole piece, second magnet steel between second pole piece and magnetic bowl, form magnetic gap between the magnetic bowl and first magnet steel and second magnet steel, first coil and second coil are housed in this magnetic gap, it is characterized in that: the pole reversal setting of first magnet steel and second magnet steel, first coil and second coil around to opposite, and the center of first coil is higher than the center of first pole piece, and the center of second coil is lower than the center of second pole piece.

2, magnetic speaker as claimed in claim 1 is characterized in that: the thickness of first magnet steel is higher than the thickness of second magnet steel.

3, magnetic speaker as claimed in claim 1 or 2 is characterized in that: the number of turn of first coil and length are greater than the number of turn and the length of second coil.