JPH0757040B2 - Speaker unit - Google Patents

Description

TECHNICAL FIELD The present invention relates to a speaker unit in an audio device.

[Conventional technology]

Conventionally, as this type of speaker unit, the one shown in FIG. 2 is known. In the figure, reference numeral (1) is a pole piece, and a magnet (2) is fixed to the pole piece by an adhesive material (4). (3) is a plate which is fixed to the magnet (2) by an adhesive (4) with a certain distance from the pole piece (1). Reference numeral (5) is a frame, which is fixed to a magnetic circuit composed of the pole piece (1), the magnet (2) and the plate (3). (6a) is a voice coil, (6b) is a diaphragm, (6c) is a dust cap, and the vibration system is constituted by these voice coil (6a), diaphragm (6b), and dust cap (6c). .
Of this vibration system, the voice coil (6a) is connected to the support member (7
It is arranged at the center of the field part of the magnetic circuit by a) and is held at the center of the diaphragm (6b). The outer peripheral portion of this diaphragm (6b) is the outer peripheral portion (5a) of the frame (5).
Is attached to the base plate via a support member (7b).

Next, the operation will be described. A driving force is generated in the voice coil (6a) located in the field part by the input signal, the driving force is propagated to the vibrating system, and the vibrating plate (6b) and the dust cap (6c) are vibrated. Sound is radiated from the diaphragm (6b) and the dust cap (6c). The fact that a driving force is generated in the voice coil (6a) means that the magnetic circuit receives a force in the opposite direction as a reaction force of the driving force. The force received by the magnetic circuit is transmitted through the frame (5) and radiated as sound from the frame outer peripheral portion (5a). As a material of the frame (5), a metal having a relatively high rigidity and a small internal loss is used as a material of the frame (5), so that sound is radiated within a time earlier than sound radiated from the vibration system.

Therefore, in consideration of mechanical strength in designing, the area of the outer peripheral portion (5a) of the frame (5) is reduced or a material with large loss is attached in order to suppress unnecessary radiation of the frame (5). It is necessary to devise. Further, the reaction force of the driving force gives unnecessary vibration to the magnetic circuit, and the large back pressure of the vibration system (6) causes the magnetic circuit to vibrate and cause resonance. Sound radiation is diaphragm (6b)
If you think that it is ideal that the other parts do not vibrate,
The frame (5) requires a material or structure having high rigidity and high internal loss.

[Problems to be Solved by the Invention]

Since the conventional speaker unit is constructed as described above, the frame (5) requires a material or structure having high rigidity and large internal loss. In order to suppress the unnecessary material of the frame (5), it is conceivable to reduce the outer peripheral area of the frame as described above, but in this case, there is a disadvantage that the opportunistic strength becomes a problem. It is conceivable to paste or apply a material with high loss, but in this case, there was a problem that workability deteriorated due to the need for post-processing. When the internal loss is small, it is difficult to suppress the unnecessary vibration of the magnetic circuit all the time. Therefore, the resonance and the long-tailed damping characteristics slow the response to the input, resulting in the deterioration of the sound quality.
There was a problem that it becomes a problem in reproducing faithful audio.

The present invention has been made to solve the problems of the conventional ones described above, and a frame having high rigidity and large internal loss is obtained, and there is no sound quality deterioration and workability is the same as that of the conventional one.
Moreover, it is an object of the present invention to provide a speaker unit that is inexpensive and can reproduce sound faithfully.

[Means for Solving the Problems]

In a speaker unit having a frame that holds at least one of a magnetic circuit and a vibration system according to the first aspect of the present invention, Si is 8 to 20% by weight in terms of weight percentage as a material forming the frame, and Fe , Zr, V, and Ti
At least one element selected from the group consisting of, or 0.05 to 0.8 wt% of the total of a plurality of elements, and 0.05 to 2 wt% of the rare earth element, Na or Sr or a total of 0.
A vibration-damping aluminum alloy containing 1% by weight or less, the balance consisting of aluminum and impurities, and the second phase particles having an average particle size of 10 μm or less is used.

In a speaker unit having a frame that holds at least one of the magnetic circuit and the vibration system according to the second aspect of the present invention, the material forming the frame is
By weight percentage, Ni is 4 to 10% by weight, and Fe, Zr, V, and
At least one element selected from the group consisting of Ti, or a total of a plurality of elements of 0.05 to 0.8% by weight, and a rare earth element of 0.05 to 2% by weight, the balance consisting of aluminum and impurities, It is made of a vibration-proof aluminum alloy having an average particle size of two-phase particles of 10 μm or less.

Further, 0.005 to 0.1% by weight of Sn is further added as a constituent material of the vibration-proof aluminum alloy used for the frame of the speaker unit according to the third invention.

[Work]

In the constituent material of the vibration-proof aluminum alloy constituting the frame according to the first and second aspects of the present invention, when Si or Ni is added to Al as in the above-mentioned constitution, Si or Al is added to the matrix Al. Ni particles precipitate and form eutectic crystals. The interface of the Si or Ni particles, which is the second phase, absorbs the vibration and improves the damping capacity. Therefore, the frame absorbs vibration to increase attenuation and suppress unnecessary radiation.

Further, by containing Fe, Zr, V, Ti and a rare earth element, the eutectic crystal is made fine and the damping ability is further improved.

Furthermore, Si particles are atomized by adding either or both of Na and Sr to the structure according to the first invention.

Further, in the constituent material of the vibration-proof aluminum alloy that constitutes the frame according to the third invention,
By adding 0.005 to 0.1% by weight of Sn to the vibration-proof aluminum alloy constituting the frame according to the invention,
By increasing the viscosity of the grain boundaries, the specific elastic modulus and internal loss of the speaker unit are improved.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral (8) is a vibration-proof aluminum alloy (Al
-Ni-based or Al-Si-based frame, and (8a) is the outer periphery. In addition, the same reference numerals as those in the conventional example shown in FIG. 2 indicate the same or corresponding portions.

Next, four examples of the present invention will be shown.

Examples 1 and 2 are Al-Si alloys, and Examples 3 and 4 are Al.
-Ni-based alloy.

In addition, all the components of these Examples are shown by weight percentage.

The "MM" in each of the above examples is a misch metal that is a mixture of rare earth metals, and its composition is La35%, Ce43%,
Nd15%, Pr4%, Sm1%, Y and other 2%.

The cause and mechanism of the damping ability of the vibration-proof aluminum alloy is
It is considered that the viscous flow at the boundary between the second-phase particles and the matrix, the viscous flow at the crystal grain boundaries and the cell grain boundaries, and the absorption of vibration energy by dislocations / vacancy and small grain defects in the crystal at the time of stacking faults.

The damping capacity Q ^-1 is a measure for converting the vibration energy given from the outside into heat energy, It is represented by.

The Al-Si alloys used in Examples (1) and (2) of the present invention are
When Si is added to l, Si particles precipitate in the matrix Al and form eutectic crystals. And the second phase
The interface of the Si particles absorbs the vibration and improves the damping capacity Q ^-1 .

Further, a mixture of Fe, Zr, V, Ti and a rare earth element or a rare earth element such as misch metal has a function of refining the eutectic crystal to increase grain boundaries, and Na and Sr are Si
It has the function of refining the particles. When Sn is further added to Example 1 as in Example 2, the Sn is finely precipitated in the crystal grain boundaries, increasing the viscosity of the grain boundaries and improving the damping capacity.

The preferred ranges (weight percentages) of the respective components in Examples (1) and (2) of the present invention are as shown in Table 1 below, and if more or less than the above ranges, the problems as shown in Table 1 occur.

Further, in the Al-Si alloys of Examples (1) and (2) of the present invention, it is necessary that the average grain size of the second phase grains (Si grains) is 10 μm or less with respect to the crystal structure. That is, by setting the average particle size of the second phase particles to 10 μm or less, the interface of the second phase particles can be increased and a large damping ability can be obtained.

Further, the average particle diameter is more preferably 7 μm or less, further preferably 5 μm or less.

Further, the Al-Ni alloys of Examples (3) and (4) of the present invention are
When Ni is added to Al, Ni particles precipitate in the matrix Al and form a eutectic structure.

Then, the interface of the Al ₃ Ni particles, which is the second phase, absorbs and improves the damping capacity Q ^-1 .

Further, a mixture of Fe, Zr, V, Ti and a rare earth element or a rare earth element such as misch metal refines the crystal to increase the grain boundaries and improve the damping capacity Q ^-1 . Further, when Sn is contained as in Example (4), the Sn is finely precipitated in the grain boundaries, the viscosity of the grain boundaries is increased, and the damping capacity Q ^-1 can be improved.

The preferred ranges (percentage by weight) of each component in Examples (3) and (4) of the present invention are shown in Table 2 below,
If the amount is larger or smaller than that, the problems shown in Table 2 occur.

Further, in the Al-Ni alloys of Examples (3) and (4) of the present invention, it is necessary that the average grain size of the second phase (Al ₃ Ni grains) is 10 μm or less in the crystal structure. That is,
By setting the average particle diameter of the second phase particles to 10 μm or less, the interface of the second phase particles can be increased and a large damping ability can be obtained.

The average particle diameter is more preferably 7 μm or less, further preferably 5 μm or less.

Next, the Al-Ni-based alloy, the Al-Si-based alloy and the Al
Table 3 below shows a comparison with (JIS name 5052) and Al-60% Zn alloy (trade name: Cosmar Z).

As is clear from Table 3, the damping capacity Q ^-1 is the Al-N of the present invention.
Both the i-based alloy and the Al-Si-based alloy are an order of magnitude larger than Al (LIS name 5052), and the elastic modulus is a little inferior, but there is almost no problem so the rigidity does not drop so much and the speaker It can be seen that the internal loss of the unit can be significantly improved compared to the conventional configuration, and it is extremely good as a material for the frame.

Recently, Al-60% Zn alloy (trade name: Cosmar Z)
However, the Al—Ni alloy and the Al—Si alloy of the present invention have a larger damping capacity, and the specific elastic modulus E / ρ (cm ² / sec ² ) proportional to the propagation velocity is also Al. -Ni-based alloys and Al-Si-based alloys are larger and have a lower specific gravity, so it is possible to provide a lightweight and highly rigid frame.

In addition, Al-60% Zn alloy (trade name: Cosmar Z) is
(JIS designation 5052), and Al-Si alloys and Al-Ni alloys of the present invention have a problem of corrosion resistance.

In the present invention, it is needless to say that the concept of the frame also includes an auxiliary frame, and the auxiliary frame can also be made of an Al-Ni-based alloy or an Al-Si-based alloy.

〔The invention's effect〕

As described above, according to the first aspect of the present invention, as a material forming the frame that holds at least one of the magnetic circuit and the vibration system of the speaker unit, the weight percentage of Si is
Is 8 to 20% by weight, 0.05 to 0.8% by weight of at least one element selected from the group consisting of Fe, Zr, and Ti, or a total of plural elements, and 0.05 to 2% by weight of rare earth elements.
And a vibration-damping aluminum alloy containing Na or Sr or 0.1% by weight or less in total, the balance being aluminum and impurities, and having the above-mentioned constitution, in which the average particle diameter of the second phase particles is 10 μm or less. By using it, it is possible to obtain a frame with large internal loss while maintaining rigidity, so unnecessary radiation of the frame can be suppressed, responsiveness to input can be improved, and faithful sound without deterioration of sound quality can be reproduced. it can.

Further, it is possible to reduce the weight of the frame while maintaining good workability that is the same as the conventional one.

Further, as a material forming a frame that holds at least one of the magnetic circuit and the vibration system of the speaker unit according to the second aspect of the present invention, Ni is 4 to 10% by weight, and Fe, Zr, and V are included in weight percentage. , And at least one element selected from the group consisting of Ti, or a total of plural elements of 0.05 to
0.8 wt% and 0.05 to 2 wt% rare earth element,
By using the anti-vibration aluminum alloy with the balance consisting of aluminum and impurities and having the average particle diameter of the second phase particles of 10 μm or less according to the above configuration, the same effect as the first invention can be obtained. it can.

Furthermore, the vibration damping aluminum alloy according to the third invention is added to the above vibration damping aluminum alloys according to the first and second inventions, and 0.005 to 0.1% by weight of Sn is further added to increase the viscosity of the grain boundary. Is further increased, the internal loss can be further improved without deteriorating the specific elastic modulus of the frame, and the same effect as the first invention can be obtained.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a speaker unit showing an embodiment of the present invention, and FIG. 2 is a vertical sectional side view showing a conventional speaker unit. In the figure, reference numeral (1) is a pole piece, (2) is a magnet, (3) is a plate, (4) is an adhesive, (6) is a vibration system, (7a) and (7b) are support members, and (8). Is a frame. The same reference numerals in the drawings indicate the same or corresponding parts.

Continuation of the front page (56) Reference JP-A-54-147825 (JP, A) JP-A-63-220699 (JP, A) Actually-opened Sho-62-143392 (JP, U) JP-B-62-54854 (JP , B2)

Claims (3)

[Claims] 1. A speaker unit having a frame for holding at least one of a magnetic circuit and a vibration system, wherein as a material constituting the frame, Si is 8 to 20% by weight, and Fe and Zr are used as a weight percentage. At least one element selected from the group consisting of, V, and Ti, or a total of plural elements of 0.05 to 0.8% by weight, and a rare earth element of 0.05 to 2% by weight, either Na or Sr, or A speaker unit characterized by using a vibration-proof aluminum alloy containing a total of 0.1% by weight or less, the balance being aluminum and impurities, and having an average particle diameter of second phase particles of 10 μm or less. 2. A speaker unit having a frame for holding at least one of a magnetic circuit and a vibration system, wherein as a material for forming the frame, Ni is 4 to 10% by weight in terms of weight percentage, and Fe and Zr. , V, and Ti, at least one element selected from the group consisting of 0.05 to 0.8% by weight, and 0.05 to 2% by weight of rare earth elements, and the balance being aluminum and impurities. A speaker unit comprising a vibration-proof aluminum alloy having a second-phase particle average particle diameter of 10 μm or less. 3. The speaker unit according to claim 1 or 2, further comprising 0.005 to 0.1% by weight of Sn as a constituent material of the vibration-proof aluminum alloy.