Embodiment
Fig. 1 is the profile of loud speaker of the present invention.Magnetic circuit 1 is set at the central authorities of bowl-type framework 5 bottoms.Magnetic circuit 1 constitutes by combination and bonding disc-shaped magnets 1a, dish type pressing plate 1b and cylindrical yoke 1c.The magnetic gap 8 of upward opening is formed between the circumferential lateral surface of the interior all sides of sidewall of yoke 1c and pressing plate 1b in magnetic circuit 1.
And voice coil unit 2 has the structure that coil 2b is wrapped in the periphery of cylindrical bodies 2a.
Because voice coil unit 2 is inserted into magnetic gap 8 and is set at the relative magnetic gap of vertical direction 8 removablely, can make vibrating membrane 3 vibrations of the last outer peripheral portion that is connected to voice coil unit 2.In the upper end of voice coil unit 2, dust cap 9 can be set to stop entering of dust.
Vibrating membrane 3 is sound generation source of loud speaker, is that major ingredient is made with paper pulp and resin, and has higher rigidity and in-fighting.The peripheral end of vibrating membrane 3 is connected with the open end of framework 5 by (first edge) 4, edge by the direction of vibration at vibrating membrane 3 outstanding (being to raise up in Fig. 1).On the other hand, interior all ends of vibrating membrane 3 are fixed to voice coil unit 2.Notice that at this first edge 4 is formed by the material such as urethanes (urethane), bipeltate, SBR rubber and cloth, so that vibrating membrane is not subjected to moving load.
Speaker damper 12 comprises damper 10 and edge (second edge) 11.That is to say that all sides of speaker damper 12 have the damper 10 (as an example of first support with first modulus of elasticity) of the wavy texture of dish type within it.Second edge 11 (as an example of second support with second modulus of elasticity) is connected to the outer circumferential side of damper 10.
Interior all ends of damper 10 be connected to than voice coil unit 2 fixedly the position of vibrating membrane 3 more near the position of magnetic circuit 1 (being downside among Fig. 1).On the other hand, the peripheral end of damper 10 is connected to framework 5 by the second outstanding edge 11 downwards.
Damper 10 has the ring structure of undulated sheet, and can stretch according to moving of voice coil unit 2 or shrink.Be similar to first edge 4 that is provided with on the vibrating membrane 3, damper 10 also is made of the material that can not apply load to the vibrating membrane 3 in the vibration.Material as being fit to damper 10 for example, comprises urethanes, bipeltate, SBR rubber, cloth etc.
In having the loud speaker of said structure, when voice signal is applied to the coil 2b of voice coil unit 2, the magnetic field in the voice coil unit 2 response magnetic gaps 8 and at vertical vibration.Along with such vibration of voice coil unit 2, vibrating membrane 3 vibrations, and sound is exported from loud speaker.At this moment, by being set, second edge 11 disposes speaker damper 12 on the peripheral end of damper 10.Thereby so the distortion of loud speaker is suppressed, and further the driving efficient of loud speaker is enhanced.
Speaker damper 12 is connected to framework 5 at the one end, and is connected to voice coil unit 2 at the other end.The effect of speaker damper 12 is the rocking of generation when suppressing voice coil unit 2 and moving.In order to follow moving of voice coil unit 2 easily, speaker damper 12 is formed undulated sheet, and make it have elasticity.
When the amplitude size of voice coil unit 2 was less, wavy texture damper 10 was not given the very big load that moves of voice coil unit 2.Yet along with the increase of the amplitude size of voice coil unit 2, load has just increased.That is to say that when the amplitude size of voice coil unit 2 was bigger, because the distortion of damper 10 is not enough, load became bigger.
Therefore, in this execution mode, the periphery of damper 10 is connected to framework 5 by second edge 11.Utilize such structure, when the increase according to the moving range (being the amplitude size) of voice coil unit 2 gives damper 10 loads, then be subjected to stress on second edge 11, and second edge 11 according to the size of this stress strain.When speaker damper 12 had such structure, even under the situation that the amplitude of voice coil unit 2 increases, utilize speaker damper 12, this amplitude also was difficult for being reduced, and the deterioration that drives efficient also is suppressed.
In addition, under the situation that begins to be out of shape at second edge 11, because the projected direction at the projected direction at second edge 11 and first edge 4 is opposite, so when vibrating membrane 3 at vertical vibration the time, the difference between load that makes progress and downward load is less.
Like this, because be provided with second edge 11 on the speaker damper 12 to suppress the increase of vibrational loading, also because the structure at first edge 4 and second edge 11 is outstanding on opposite mutually direction, so be not easy to be created in the difference of the vibrational loading of vertical direction.Therefore, can obtain the little loud speaker of distortion.
In addition, in the loud speaker of present embodiment, speaker damper 12 is connected to framework 5 by second edge 11, has been increased to a certain degree up to voice coil unit 2 amplitude sizes, can the guaranteed output linearity by the damper 10 that forms undulated sheet.In addition, when the amplitude size of voice coil unit 2 reaches or greater than predetermined value and when being not easy to guarantee the linearity, the linearity that can utilize the elasticity at second edge 11 to come compensation power.Therefore, preferably, the modulus of elasticity at second edge 11 is set to the modulus of elasticity bigger (rigidity is bigger) than wavy texture damper 10.
In addition, preferably, wavy texture damper 10 has different modulus of elasticity respectively with second edge 11, makes them work alone according to the amplitude size of voice coil unit 2.For this reason, adjust the modulus of elasticity between the damper 10 and second edge 11, more particularly, the modulus of elasticity of the connecting portion 13 at the damper 10 and second edge 11 is set to the modulus of elasticity bigger (rigidity is bigger) than the damper 10 or second edge 11, thereby guarantees the independence between the damper 10 and second edge 11.At this, connecting portion 13 is the overlapped parts of the damper 10 and second edge 11.Their overlapped states can be that the damper 10 and second edge 11 are bonded together with adhesive, perhaps can be the inside that damper 10 is inserted into second edge 11.
Specifically, for the modular ratio damper 10 of the connecting portion 13 that makes the damper 10 and second edge 11 and the modulus of elasticity bigger (rigidity is bigger) at second edge 11, for example, adhesive as second edge 11 and damper 10 are bonded together preferably uses the hard adhesive such as acryloid cement.Alternatively, second edge 11 and damper 10 are mutually combined to increase the thickness of connecting portion 13 by insert moulding (insertmolding).Alternatively, reinforcement material is attached to connecting portion 13, thereby increases the modulus of elasticity of connecting portion 13.
In addition, in order to ensure the power linearity, optimize the damper 10 and second edge 11 modulus of elasticity separately as the vibrating membrane 3 in the sounding zone of loud speaker.In addition, preferably, the relation between the speaker damper 12 that combines the damper 10 and second edge 11 and first edge 4 that is arranged at vibrating membrane 3 is optimized.
That is, the emphasis of this relation is, as the to what extent evenly vibration on above-below direction freely of vibrating membrane 3 of the essence sound generation source of loud speaker.Consider this point,, preferably, the modulus of elasticity that combines the speaker damper 12 at the damper 10 and second edge 11 is set at the modulus of elasticity at first edge 4 that equals to be arranged on vibrating membrane 3 substantially in order to make full use of the linearity of vibrating membrane 3.
For this reason, in the present embodiment, as shown in Figure 1, the size at second edge 11 is set at size less than first edge 4.
That is, because damper 10 has wavy texture and have less modulus of elasticity (that is, damper 10 is very soft), the size by making second edge 11 makes that less than the size at first edge 4 modulus of elasticity at second edge 11 is bigger (that is, rigidity is bigger).Thus, the modulus of elasticity that combines the speaker damper 12 of second edge 11 and damper 10 can be similar to the modulus of elasticity at first edge 4 as much as possible.
Vibrating membrane 3, voice coil unit 2 and the speaker damper 12 in the zone between first edge 4 and second edge 11 can be regarded as the rigid body of a combination.So, when the spacing that increases between first edge 4 and second edge 11, can suppress rocking and reducing distortion of voice coil unit 2.So, in order to ensure the spacing between first edge 4 and second edge 11, make first edge 4 outstanding, and make second edge 11 outstanding to the direction opposite with vibrating membrane 3 to the direction opposite with damper 12.Thereby increased the spacing between first edge 4 and second edge 11.Thereby, can suppress rocking and reducing distortion of voice coil unit 2.
Fig. 2 and Fig. 3 have shown an alternative embodiment of the invention.At this, be different from second edge 11 shown in Figure 1, be provided with the second edge 11a (example of support).
Be similar to first edge 4 that is arranged on the vibrating membrane 3, the second edge 11a is by forming such as urethanes, bipeltate, SBR rubber (butadiene-styrene rubber Styrene-butadiene rubber) and the material of cloth, not apply load to vibrating membrane 3 when the vertical vibration.The second edge 11a does not have the such half-round section shape in second edge 11 shown in the image pattern 1.
In other words, can free in vertical direction and vibration equably in order to allow as the vibrating membrane 3 of the essence sound generation source of loud speaker, preferably, make the modulus of elasticity of the speaker damper 12a that combines the damper 10 and the second edge 11a approach to be arranged on the modulus of elasticity at first edge 4 of vibrating membrane 3.For this reason, be similar to present embodiment, preferably, make the second edge 11a have the undulated sheet shape, rather than semi-circular shape.When the second edge 11a is formed undulated sheet, advantageously make the modulus of elasticity of speaker damper 12a approach to be arranged on the modulus of elasticity at first edge 4 of vibrating membrane 3.