JP2011139256A - Speaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that sound quality deteriorates in accordance with the reduction in the weight of a speaker. <P>SOLUTION: The speaker used for a vehicle includes a resin frame, a magnetic circuit provided at the center of the resin frame, a voice coil to be inserted into a magnetic gap of the magnetic circuit, a damper fixed to the voice coil and the resin frame, and a diaphragm fixed to the resin frame and the voice coil, wherein an outer circumference part of the resin frame and a fixed part of the damper are connected by a plurality of frame arms, a hollow is provided in a connection part between the frame arms and the outer circumference part of the resin frame, and the deterioration in sound quality due to weight reduction can be improved while keeping the reduction of the weight of the speaker by filling the hollow with a damping agent. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a speaker used for in-vehicle use.

  In recent years, in the automobile industry, weight reduction is inevitable from the viewpoint of improving fuel efficiency and saving resources.

  For this reason, the weight reduction of a speaker is progressing as a part of vehicle body weight reduction centering on the vehicle-mounted genuine speaker.

  Therefore, these in-vehicle speakers have a smaller magnetic circuit, a frame that is made of resin from metal, further thinned and reduced in rigidity, and many factors that cause sound quality degradation compared to speakers that do not reduce weight. It tends to hold.

  Hereinafter, a conventional speaker will be described with reference to the drawings.

  FIG. 3 is a cross-sectional view of a conventional speaker.

  As shown in FIG. 3, 21 is a magnetic circuit, 22 is a plate, 23 is a magnet, 24 is a yoke, 25 is a resin frame, 25a is a frame arm constituting the resin frame 25, 26 is a voice coil, 27 is a damper, 28 Is a diaphragm, and 29 is a dust cap.

  Here, this speaker is configured such that the voice coil 26 is driven by the magnetic circuit 21 and the vibration is transmitted to the diaphragm 28 to generate sound.

  The resin frame 25 plays a role of firmly supporting a vibration component including the magnetic circuit 21, the voice coil 26, and the diaphragm 28.

  For example, Patent Document 1 is known as prior art document information relating to the invention of this application.

JP-A-6-245295

  Usually, when a driving force is generated in a general speaker, it is assumed that the magnetic circuit does not move.

  However, when the voice coil is driven in the magnetic circuit, the reaction causes the magnetic circuit to vibrate, and the driving force is also modulated.

  When the magnetic circuit is heavy and the frame rigidity is high, the influence of this vibration is small.

  However, in recent automobile speakers, as a result of weight reduction, the magnetic circuit is reduced in size, the frame is made of resin, and the thickness is reduced to reduce the rigidity.

  In such a speaker, the magnetic circuit has a problem that it is susceptible to a reaction due to the driving force of the voice coil, and the sound quality is greatly deteriorated.

  The present invention solves the above-described problems, and an object of the present invention is to provide a speaker that can achieve high sound quality while being a lightweight speaker.

  In order to solve the above problems, a speaker of the present invention includes a resin frame, a magnetic circuit provided at the center of the resin frame, a voice coil inserted into a magnetic gap of the magnetic circuit, and the voice coil and the resin frame. A damper fixed to the resin frame, and a diaphragm fixed to the resin frame and the voice coil. The outer periphery of the resin frame and the fixed portion of the damper are connected by a plurality of frame arms. In addition, a recess is provided in the coupling portion, and the recess is filled with a braking agent.

  With the above configuration, the speaker of the present invention has the effect of being able to effectively reduce vibration caused by the reaction of the magnetic circuit with a slight amount of braking agent. It is possible to improve the sound quality deterioration due to the sound, and to achieve a great effect that it is possible to realize high sound quality while being a lightweight speaker.

Half sectional view of the speaker of the present invention Equivalent circuit diagram of speaker of the present invention Half sectional view of a conventional speaker Equivalent circuit diagram of conventional speaker Half sectional view showing the improved state of a conventional speaker Equivalent circuit diagram showing improved state of conventional speaker

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
Hereinafter, the first aspect of the present invention will be described with reference to the first embodiment.

  FIG. 1 is a half sectional view of a speaker of the present invention. 1 is a magnetic circuit, 2 is a plate, 3 is a magnet, 4 is a yoke, 5 is a resin frame, 5a is a frame arm constituting the resin frame 5, and 6 is a voice. A coil, 7 is a damper, 8 is a diaphragm, 9 is a dust cap, 10 is a recess provided in the resin frame 5, and 11 is a braking agent.

  Here, this speaker is configured such that the voice coil 6 is driven by the magnetic circuit 1 and the vibration is transmitted to the diaphragm 8 to generate sound.

  The resin frame 5 serves to firmly support the vibration component including the magnetic circuit 1, the voice coil 6, and the diaphragm 8, and the reaction of the magnetic circuit 1 by the braking agent 11 filled in the recess 10. Reduces vibration caused by

  FIG. 2 is an equivalent circuit of the speaker of the present invention shown in FIG. 1 including the vibration element of the magnetic circuit.

  2, F is the driving force, V is the vibration system speed, Vg is the vibration speed of the magnetic circuit, Zme is the electromagnetic braking resistance, Mm is the vibration system mass, Cm is the vibration system compliance, Rm is the vibration system mechanical resistance, Ma Is the radiation mass, Ra is the radiation resistance, Mvg is the vibration mass of the magnetic circuit, Mvf is the vibration mass of the frame, Cvf is the vibration compliance of the frame, Rvf is the vibration mechanical resistance of the frame, and Rv11 is the vibration mechanical resistance due to the braking agent 11. .

  Next, FIG. 3 is a half sectional view of a conventional speaker.

  3, 21 is a magnetic circuit, 22 is a plate, 23 is a magnet, 24 is a yoke, 25 is a resin frame, 25a is a frame arm constituting the resin frame 25, 26 is a voice coil, 27 is a damper, and 28 is a diaphragm. 29 are dust caps.

  FIG. 4 is an equivalent circuit of the conventional speaker shown in FIG. 3 including the vibration element of the magnetic circuit.

  Further, FIG. 5 is an improvement example of the conventional speaker shown in FIG.

  FIG. 6 is an equivalent circuit of the speaker including the vibration element of the magnetic circuit, and Rv30 is the vibration mechanical resistance due to the braking material 30.

  In general, as shown in FIG. 4, in the speaker, the driving force F generates the speed V in the vibration system, and at the same time, the magnetic circuit generates the vibration speed Vg of the magnetic circuit. If the magnetic circuit 21 and the frame 25 are heavy and the vibration mass Mvg of the magnetic circuit and the vibration mass Mvf of the frame are large, the vibration speed Vg of the magnetic circuit is low. However, in the lightweight speaker as shown in FIG. The vibration mass Mvf of the frame decreases, the vibration speed Vg of the magnetic circuit increases, and the loss of the driving force F increases.

  Further, when the rigidity of the resin frame 25 or the like is low, the vibration compliance Cvf of the frame is large, and the vibration speed Vg of the magnetic circuit tends to flow due to a decrease in mechanical impedance.

  Further, in the vicinity of Fo, which is the lowest resonance frequency, the electromagnetic braking resistance Zme increases, so that the vibration system speed V decreases and the magnetic circuit vibration speed Vg increases.

  For this reason, the sound quality deterioration due to the vibration of the magnetic circuit 21 is large, and particularly the sound quality deterioration of the bass sound is severe.

  FIG. 5 shows an improvement example in which the sound quality of the conventional speaker shown in FIG. 3 is attempted to be improved, and a braking material 30 is added to the frame arm 25a.

  In such a case, as shown in FIG. 6, Rv30 exists as a distributed constant among the vibration mass Mvf of the frame, the vibration compliance Cvf of the frame, and the vibration mechanical resistance Rvf of the frame.

  Since the subdivided Rv30 has a weak individual braking force and may pass through the vibration speed Vg of the magnetic circuit, the vibration mechanical resistance is small even in total.

  Therefore, it is difficult to suppress the vibration speed Vg of the magnetic circuit with a small amount of the braking material 30 allowed for the lightweight speaker.

  In the loudspeaker of FIG. 1 according to the present invention, a recess 10 is provided at the joint between the outer periphery of the resin frame 5 and the frame arm 5a, and the braking agent 11 is concentrated and filled in the recess.

  The recess 10 has a shape that does not reduce the mechanical strength.

  In such a structure, as shown in FIG. 2, it is considered that the vibration mechanical resistance Rv11 due to the braking agent 11 exists independently from the vibration mass Mvf of the frame and the vibration compliance Cvf of the frame, and can be treated as a lumped constant.

  For this reason, the vibration speed Vg of the magnetic circuit reliably passes the vibration mechanical resistance Rv11 due to the braking agent 11.

  Further, by concentrating at one place, the viscous resistance is increased, and the value as the vibration mechanical resistance Rv11 by the braking agent 11 is increased, so that the vibration speed Vg of the magnetic circuit can be effectively suppressed.

  As a result, even a very small amount of the braking agent 11 in the lightweight speaker can reduce the vibration of the magnetic circuit 1 and improve the sound quality deterioration.

  Next, the invention according to the second aspect of the present invention will be described.

  The difference from the above-described embodiment is that the recess 10 is provided only at the connecting portion of the main frame arms among the plurality of frame arms, and the braking agent 11 is filled.

  With this configuration, it is possible to improve the degree of freedom in frame design related to formability and the workability of filling the braking agent.

  Next, the invention according to the third aspect of the present invention will be described.

  The difference from the above-described embodiment is that the braking agent 11 is made of a silicon-based resin.

  With this configuration, it is possible to improve reliability such as heat resistance, which is a characteristic of silicon-based resins, and stability of performance.

  Furthermore, the use of a silicon-based adhesive or pressure-sensitive adhesive can be advantageous in terms of production method and standardization.

  Next, the invention according to the fourth aspect of the present invention will be described.

  The difference from the above-described embodiment is that the amount of the braking agent 11 is set to 1% or less of the total weight of the speaker.

  According to experiments, in a 16 cm speaker with a total weight of 210 g, a great sound quality improvement effect was obtained even with the braking agent 11 having a total weight of 0.3% (0.7 g).

  Here, if the amount of the braking agent 11 exceeds 1% of the total weight of the speaker, it cannot be said that it is preferable from the viewpoint of reducing the weight of the speaker. Can be tolerated.

  From this result and the viewpoint of maintaining light weight, it can be said that a braking agent of 1% or less of the total weight of the speaker is necessary and sufficient.

  The speaker according to the present invention can be applied to a speaker that is required to be improved in sound quality deterioration due to weight reduction while maintaining the weight reduction in in-vehicle applications.

DESCRIPTION OF SYMBOLS 1 Magnetic circuit 2 Plate 3 Magnet 4 Yoke 5 Resin frame 5a Frame arm 6 Voice coil 7 Damper 8 Diaphragm 9 Dust cap 10 Depression 11 Braking agent 21 Magnetic circuit 22 Plate 23 Magnet 24 York 25 Resin frame 25a Frame arm 26 Voice coil 27 Damper 28 Diaphragm 29 Dust cap 30 Braking material F Driving force V Vibration system speed Vg Magnetic circuit vibration speed Zme Electromagnetic braking resistance Mm Vibration system mass Cm Vibration system compliance Rm Vibration system mechanical resistance Ma Radiation mass Ra Radiation resistance Mvg Magnetic circuit Vibration mass of Mvf Frame vibration mass Cvf Frame vibration compliance Rvf Frame vibration mechanical resistance Rv11 Vibration mechanical resistance due to braking agent 11 Rv30 Vibration mechanical resistance due to braking material 30

Claims (4)

A resin frame; a magnetic circuit provided in the center of the resin frame; a voice coil inserted into a magnetic gap of the magnetic circuit; a damper fixed to the voice coil and the resin frame; the resin frame; A speaker comprising a diaphragm fixed to a voice coil, wherein the speaker connects an outer peripheral portion of the resin frame and a fixed portion of the damper by a plurality of frame arms, and the frame arm and the outer periphery of the resin frame A speaker in which a recess is provided in a coupling portion with the portion, and the recess is filled with a braking agent. The speaker according to claim 1, wherein a recess is provided only in a joint portion of main frame arms among a plurality of frame arms and filled with a braking agent. The speaker according to claim 1, wherein the braking agent is made of a silicon-based resin. The speaker according to any one of claims 1 to 3, wherein the amount of the braking agent is 1% or less of the total weight of the speaker.

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