JPH0752995B2 - Diaphragm for audio equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a diaphragm for an acoustic device in an acoustic device.

[Conventional technology]

In general, a diaphragm for an acoustic device is a single plate, a structure in which a plurality of plates are bonded together, or a structure in which a diaphragm is bonded to the outermost layers on the front and back of a core material filled with a honeycomb structure or foamed resin. is there. Further, these diaphragm materials have conventionally been constituted of natural or synthetic fiber single paper, mixed paper or resin film, metal such as aluminum, and the like.

Next, this diaphragm will be described. Generally, a diaphragm for an acoustic device (hereinafter referred to as a diaphragm) is required to have a large specific elastic modulus, bending rigidity and internal loss. Here, the larger the specific elastic modulus Ε / ρ (where Ε is Young's modulus and ρ is density), the higher the limit resonance frequency and the wider the reproduction frequency band. In addition, the larger the bending rigidity E · I (I is the second moment of area), the more the strain is reduced, and the larger the internal loss, the sharper the Q value of mechanical resonance is, and the flatness of the characteristics can be achieved. It is possible to obtain a good vibration plate. Conventionally, various diaphragm materials have been adopted from such a viewpoint. However,
Since these characteristics have mutually contradictory elements,
It was very difficult to satisfy all with the existing single material. In order to solve these problems, it may be possible to use a diaphragm that uses a composite stacking method that uses two or more different materials, and to devise a method that balances mutually contradictory elements, especially high elasticity, high rigidity, and high internal loss. However, it was not completely satisfactory from an industrial point of view, because the specific elastic modulus decreased and the productivity was poor and the cost was high.

[Problems to be Solved by the Invention]

Since the conventional diaphragm is configured as described above, a diaphragm with a large specific elastic modulus Ε / ρ has a very small internal loss, and a metal plate such as aluminum, which has a particularly high elastic modulus, has an internal loss. However, due to the small value, a peak dip occurred in the frequency characteristics, and good characteristics could not be obtained. Also,
When paper and polymer diaphragms are used together to increase the internal loss, the specific elastic modulus Ε / ρ is low and the critical resonance frequency is low.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to obtain an excellent diaphragm that improves the specific elastic modulus and internal loss of the entire diaphragm and has the same workability and handleability as those of the conventional diaphragm. To do.

[Means for Solving the Problems]

The diaphragm for an acoustic device constituted by a single or a plurality of layers according to the first aspect of the present invention is, as a material of at least one layer of the single or a plurality of layers, Si in a weight percentage of 8 to 20% by weight, Fe, Z
At least one element selected from the group consisting of r, V, and Ti, or a total of 0.05 to 0.8% by weight of a plurality of elements, and 0.05 to 2% by weight of a rare earth element, and either Na or Sr. Or, it contains less than 0.1% by weight in total, the balance consisting of aluminum and impurities, and the average particle diameter of the second phase particles is 10μ.
A vibration-proof aluminum alloy having a thickness of m or less is used.

Further, the diaphragm for an acoustic device according to the second aspect of the present invention, which is composed of a single or a plurality of layers, has a weight percentage of Ni of 4 to 10% by weight as a material for at least one layer of the single or a plurality of layers. ,
It contains at least one element selected from the group consisting of Zr, V, and 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, and the balance of aluminum and The vibration-damping aluminum alloy, which is made of impurities and has an average particle diameter of the second phase particles of 10 μm or less, is used.

Further, 0.005 to 0.1% by weight of Sn is further added as a constituent material of the vibration-proof aluminum alloy used in at least a part of the diaphragm for an acoustic device according to the third invention.

[Action]

In the structure of the vibration-proof aluminum alloy according to the first and second inventions, as in the above-mentioned structure, Si or Al in Si or
When Ni is added, Si or Ni particles are precipitated in Al that is a matrix to form a eutectic crystal. And is the second phase
The interface of Si or Ni particles absorbs the vibration and improves the damping ability.

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 made finer by adding one or both of Na and Sr to the structure according to the first invention.

Furthermore, in the structure of the vibration-damping aluminum alloy according to the third invention, by adding 0.005 to 0.1% by weight of Sn to the vibration-damping aluminum alloy according to the first and second inventions, the viscosity of the grain boundary can be increased. As a result, the specific elastic modulus and internal loss of the diaphragm are improved.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment, which comprises a single diaphragm (1), which is formed of a vibration-proof aluminum alloy.
FIG. 2 shows a second embodiment, which is a vibration plate in which a plurality of plates (1a) and (1b) are bonded together, and at least one surface is made of a vibration-proof aluminum alloy. FIG. 3 shows a third embodiment, in which at least one surface of the vibration plates (1a) and (1b) bonded to the front and back surfaces of the core material (1c) filled with the honeycomb structure or the foamed resin is made of vibration-proof aluminum. It is made of an alloy.

Four examples of the vibration-proof aluminum alloy used for the diaphragm in the present invention will be shown.

Examples 1 and 2 are Al-Si alloys, and Examples 3 and 4 are Al-N.
It is an i-based alloy.

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

Note the term "MM" in each example are mischmetal which is a mixture of rare earth metals, this _{composition, L a 35%, C e} 43
_{%, Nd15%, P r 4} %, S m 1%, a Y other 2%.

The cause and mechanism of the damping capacity of the vibration-proof aluminum alloy are
It is considered that viscous flow at the boundary between the second-phase particles and the matrix, viscous flow at the crystal grain boundaries and cell grain boundaries, and absorption of vibration energy by minute defects in the crystal such as dislocations / voids and 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 alloy used in Examples (1) and (2) of the present invention is Al
When Si is added, Si particles precipitate in the matrix Al and form eutectic crystals. And the second phase, Si
The interface of the 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 crystal to increase the grain boundary, and Na and Sr refine Si particles. It has a function. 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 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.

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 A
When Ni is added to l, 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, the average grain size of the second phase (Al ₃ Ni particles) is preferably 10 μm or less, and 10 μm or less with respect to the crystal structure. By doing so, the interface of the second phase particles can be increased and a large damping capacity can be obtained.

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

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

As is clear from Table 3, the damping capacity Q ^-1 is the Al-Ni of the present invention.
Both the Al-based alloys and Al-Si based alloys are one digit or more larger than Al (JIS designation 5052). As a result, the internal loss of the entire diaphragm can be significantly improved compared to the conventional configuration, and it is extremely good as a diaphragm for an acoustic device. In addition, the specific elastic modulus is similar to that of Al (JIS name 5052), which has excellent properties, and the specific elastic modulus Ε / ρ is superior to that of Al-60% Zn (Cosmar Z), and the weight is reduced. be able to. further,
It has a good damping capacity, but in order to obtain the internal loss of the whole diaphragm, the conventional process to bond multiple materials to give an internal loss (resulting in a specific elastic modulus of the diaphragm Has to be made smaller), and the degree of freedom in design becomes higher. FIG. 4 and FIG. 5 are characteristic diagrams showing the characteristics according to the above-described embodiment. The solid line shows the conventional product and the broken line shows the embodiment, and the frequency characteristics and sound pressure distortion are improved. Recognize. In addition, although the diaphragm for the audio device has been described in the above-mentioned embodiment, it may be a dust cap, and the same effect as that in the above-mentioned embodiment is obtained.

〔The invention's effect〕

According to the first invention, as a material of at least one layer of a single or a plurality of layers of a diaphragm for an acoustic device, Si is 8 to 20% by weight and a group consisting of Fe, Zr, V, and Ti. At least one element selected from the above, 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, and Na or Sr, or a total of 0.1% by weight or less. By using a vibration-proof aluminum alloy whose balance consists of aluminum and impurities and whose average particle diameter of the second phase particles is 10 μm or less by the above structure, the inside of the diaphragm can be maintained while maintaining a high specific elastic modulus. Since the loss can be remarkably improved, it is possible to obtain an inexpensive diaphragm for an acoustic device, which has good reproduction frequency characteristics with a small peak dip, is light in weight, and has good productivity.

Further, as a material of at least one layer of a single or a plurality of layers of the diaphragm for an acoustic device according to the second invention, the weight percentage is
Ni of 4 to 10% by weight, at least one element selected from the group consisting of Fe, Zr, V, and Ti, or a total of plural elements of 0.05 to 0.8% by weight, and rare earth elements of 0.05 to Two
% By weight, the balance consisting of aluminum and impurities, and the average particle diameter of the second phase particles of 10 μ
By using the vibration-damping aluminum alloy having a thickness of m or less, the same effect as that of the first invention can be obtained.

Furthermore, by adding 0.005 to 0.1% by weight of Sn to the structure of the vibration damping aluminum alloy according to the first and second aspects of the vibration damping aluminum alloy according to the third invention, the viscosity of the grain boundary can be increased. By further increasing the above, it is possible to obtain a diaphragm for an acoustic device in which the internal loss is further improved without impairing the specific elastic modulus.

[Brief description of drawings]

FIG. 1 is a sectional side view showing an embodiment of the present invention, FIGS. 2 and 3 are sectional side views showing another embodiment of the present invention, and FIG. 4 is an example of frequency characteristics according to a conventional product and the present invention. And FIG. 5 are diagrams showing an example of the sound pressure distortion characteristics according to the present invention and the conventional product (1), (1a), (1b) ..... Vibration plate The same reference numerals in the drawings are the same. Or, shows a considerable portion.

Claims (3)

[Claims] 1. A diaphragm for an acoustic device comprising a single layer or a plurality of layers, wherein as a material for at least one layer of the single layer or the plurality of layers, Si is 8 to 20% by weight, and Fe and Zr. , V, and Ti, or at least one element selected from the group consisting of Ti, or 0.05 to 0.8% by weight of the total of plural elements, and 0.05 to 2% by weight of a rare earth element, and either Na or Sr. A diaphragm for an acoustic device, comprising a vibration-damping aluminum alloy containing 0.1% by weight or less in total, the balance being aluminum and impurities, and having an average grain size of second phase particles of 10 μm or less. 2. A diaphragm for an acoustic device comprising a single layer or a plurality of layers, wherein as a material of at least one layer of the single layer or the plurality of layers, Ni is 4 to 10% by weight in percentage by weight, 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 diaphragm for an acoustic device, comprising a vibration-damping aluminum alloy having a second-phase particle average particle diameter of 10 μm or less. 3. The diaphragm for an acoustic device according to claim 1, further comprising 0.005 to 0.1% by weight of Sn as a constituent material of the vibration-proof aluminum alloy.