JPS603541Y2 - speaker network - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a speaker network, and in particular, to a speaker network in which electrical components constituting the network are covered with a compound having low resonance sharpness to prevent the electrical components from resonating.

Conventionally, one type of speaker system is one in which three speakers for bass, medium, and treble are housed in one cabinet.

In this case, a 12 dB 10 ct network is connected between the input terminal of the speaker and the voice coil of each speaker.

This network is constructed of low-pass, band-pass, and bypass filters using coils and capacitors, or a plurality of combinations thereof.

For example, as shown in FIG. 1, 1 and 2 are coils and capacitors that constitute a low-pass filter;
, 6 are coils and capacitors forming a bandpass filter, and 7 and 8 are capacitors and coils forming a bypass filter.

Conventionally, each of these components has been simply mounted on a printed circuit board and housed in a speaker cabinet without any special treatment.

Therefore, for example, when a large current flows through coil 1 of a low-pass filter, magnetic flux is generated by the current flowing through the coil.
This magnetic flux causes a phenomenon in which the coils wound a large number of times repel or attract each other, causing the coils to move.

This phenomenon can be said to be resonance that occurs at a certain frequency or at several points in a harmonic frequency relationship based on this frequency.

Therefore, when an input signal that matches the resonant frequency of the coil is supplied to the network, the coil resonates, and this resonance distorts the signal supplied to the voice coil, resulting in distortion in the reproduced sound.

This phenomenon is particularly likely to occur in a network of bass speakers to which a large amount of power is supplied.

Similarly, the reproduced sound of the capacitor 2 is distorted due to the repulsive force between the foils.

The present invention provides a speaker network that improves these drawbacks.

In FIG. 2, 10 is a coil member corresponding to 1 in FIG. 1 covered with a compound to be described later.

As shown in FIG. 3, this member 10 has a core 11 inside.
, has a coil 12 wound in three layers, for example, so as to wind this core 11.

These parts are covered with a bulk molding compound 13 (hereinafter simply referred to as BMC).

BMC13, for example, mainly consists of a resin component made of unsaturated polyester resin and thermoplastic resin, and a reinforcing material made of glass fiber and inorganic filler, with addition of colorants, mold release agents, thickeners, polymerization initiators, etc. It consists of

The filler is a known inorganic substance such as calcium carbonate, barium sulfate, magnesium carbonate, clay, silica, talc, etc., and by appropriately selecting the type and amount of the filler, the specific gravity of the molded product can be adjusted. Can be increased or decreased,
Furthermore, the physical properties and appearance can also be changed.

The blending amount is appropriately selected within the range of 35 to n% by weight based on the total acid composition.

The amount of resin used is preferably an amount corresponding to 20 to 3% by weight.

The thermoplastic resin blended into the resin component is used to maintain low shrinkage during molding, and is usually a crosslinking agent for unsaturated polyester resin, specifically styrene and its derivatives, (meth) It is dissolved and blended into a polymerizable monomer such as acrylic ester or diallyl phthalate.

The thermoplastic resin solution is blended in the resin content in an amount of 25 to 4% by weight, and the thermoplastic resin is blended in the crosslinking agent solution in an amount of 25 to 5% by weight.
It is preferable that

As the thermoplastic resin, known resins used to impart low shrinkage to unsaturated polyester resin molding materials, such as (meth)acrylic resin, styrene resin, saturated polyester resin, vinyl chloride resin, and vinyl acetate resin, are used. It will be done.

Glass fiber contributes to the mechanical strength and vibration absorption properties of the molded article, and is contained in an amount within the range of 8 to 4% by weight in the total composition.

Its content is 8%. When the value is small, Young's modulus decreases,
On the other hand, if it exceeds 40%, it becomes difficult to knead the resin and filler, and molding becomes difficult.

In this way, MC has a high Young's modulus and a low resonance sharpness.
It also has excellent permeability and moldability.

Therefore, the coil 12 and core 11 are placed in the mold, and B
When MC is injected, BMC also enters the coil 12, and the coil 12 is eventually fixed.

Therefore, even if a current flows through the coil 12 and a magnetic force is generated, it is possible to prevent the coil 12 itself or the coil 12 and the core 11 from moving relative to each other due to the magnetic force.

When the coil 12 is fixed in this manner, resonance of the coil is prevented, and sound is reproduced without distortion at any frequency.

It is also possible to use a generally well-known resin material, such as ABS resin, as a material for covering the coil, but it has a high resonance sharpness, and even if the coil is covered, the covering itself will have a resonance frequency. Therefore, it is not desirable.

In the above embodiment, the coil is covered with BMC, but if the capacitor shown in FIG. 1 is covered with BMC as shown in FIG. 4, distortion can be similarly prevented.

In FIG. 4, 15 is a capacitor body in which dielectric layers and conductive layers are alternately arranged, and 16 is a BMC that covers the capacitor body.

Note that it is possible to interpose an insulating resin 17 between the capacitor body 15 and the 8MC16.

The above-mentioned BMC used in the present invention mainly consists of a resin component consisting of an unsaturated polyester resin and a thermoplastic resin, and a reinforcing material consisting of glass fibers and an inorganic filler, and additives are added to the above-mentioned glass. 8 to 8 fibers in the total composition
Since it is contained in an amount within the range of 4% by volume, not only the resonance sharpness decreases but also the Young's modulus increases.

A high Young's modulus means that the resonant frequency of the entire network, including the coil and capacitor, can be increased.

In other words, it is equivalent to an increase in stiffness,
The high resonance frequency can be increased.

Therefore, when the present invention is used in a speaker woofer network, it is possible to change the crossover point in terms of frequency characteristics with a mid-range speaker unit, and the so-called single-note production seen from the speaker system as a whole is combined with Q-dump. , it is possible to easily produce what the designer intended.

[Brief explanation of drawings]

Figure 1 is a circuit diagram showing the speaker network, Figure 2 is an inclined view showing a coil member covered with BMC, Figure 3 is a sectional view taken along the line ■-■ in Figure 2, and Figure 4 is a sectional view of a capacitor. It is. 1.3, 4, 8... Coil, 2, 5, 6.7.
... Capacitor, 10 ... Coil member,
12... Coil, 13... BMC0

Claims (1)

[Scope of utility model registration request] It consists of a filter that allows frequencies in a predetermined range to pass through a coil and a capacitor, and at least one of the coil and capacitor is reinforced with a resin component made of an unsaturated polyester resin and a thermoplastic resin, and a glass fiber and an inorganic filler. 1. A speaker network comprising a bulk molding compound consisting mainly of wood, to which additives are added, and containing the above-mentioned glass fibers in an amount within the range of 8 to 4% by weight based on the total composition.