JPH02146899A - Speaker diaphragm member - Google Patents

Abstract

PURPOSE:To attain laborsaving and to improve the finished accuracy of a speaker diaphragm member by applying mold forming to a diaphragm made of injection engineering plastic, an edge part and a voice coil bobbin integrally. CONSTITUTION:The speaker diaphragm member is formed by molding integrally a diaphragm 1 made of injection engineering plastic, and edge part 2 and a voice coil bobbin 3. A molten liquid at a high temperature of an engineering plastic is injected from a pin point gate provided to the center of the diaphragm with a pin point metallic die, injection forming is applied, and by laborsaving, finished accuracy of the speaker diaphragm is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention mainly relates to the structure of a vibrating member of a speaker having a dome-shaped diaphragm.

<Prior Art> Conventionally, speakers having this type of dome-shaped diaphragm include a so-called horn-type speaker that applies acoustic load to the diaphragm (1) that radiates sound through a horn, or a horn-type speaker that uses a horn on part or all of the diaphragm. Air-loaded speaker with no load (
soft dome shape), etc.

The diaphragm (1) has a hemispherical dome shape at the center, and an edge part (2) (most of the external shapes are corrugated) that maintains vibration compliance is glued or integrally molded on the outer periphery of the diaphragm. (2) It is held by a holding part that suppresses and holds the outer periphery.

Furthermore, a cylindrical voice coil bobbin (3) inserted and suspended in the annular magnetic gap of the magnetic circuit and having one end bonded to the dome-shaped outer circumferential portion of the diaphragm has a cylindrical voice coil bobbin (3) in a portion opposite to the magnetic pole surface;
It is wrapped around an electrical conductor that carries audio current.

Then, when an audio current is applied from the outside to the electric conductor,
The magnetic field generated by the audio current flowing through the voice coil and the magnetic field in the magnetic air gap generate electromagnetic induction, causing the voice coil to vibrate in the axial direction.The vibration is transmitted to the diaphragm through the outer circumference of the diaphragm, causing vibration. The plate vibrates the air around the diaphragm, producing sound.

From a structural point of view, the diaphragm and edge portion are integrally molded (conventionally impregnated with phenol range resin).
In the case of a metal plate such as a titanium diaphragm, the diaphragm and the edge portion are often integrally molded using a press machine.

Therefore, although the voice coil is concentric (axial) with the diaphragm or edge portion, it occupies a three-dimensional relative positional relationship, so as shown in FIG.
3) Connect the electric conductor (voice coil) to J! After turning and fixing the material, glue the adhesive (
14), a structure in which the diaphragm (11) is concentrically bonded to the diaphragm (11) with an adhesive is usually adopted.

<Problem to be solved by the invention> Therefore, in order to vibrate while maintaining the amplitude without touching the domain wall in the structurally narrow magnetic gap as described above, the vibration must be 0.011.
Dimensional accuracy of one order of magnitude is required.

However, it is very difficult to align the center of the outer periphery of the dome-shaped diaphragm (11). ) is distorted, the adhesive part is difficult to fix, and the axis tends to tilt, making it extremely difficult to concentrically and perpendicularly adhere the diaphragm (11) to the bobbin (13), resulting in a high rate of defects in the manufacturing process. This is the most expensive process.

In addition, gold! There is a technique in which a JT diaphragm and a voice coil bobbin are integrally formed using a press machine. However, since this technology takes advantage of the malleability of metals such as aluminum, it requires many press dies (probably several sides), making the unit price high and making it difficult to form corrugations. The accuracy of the alignment of the edges, diaphragm, and voice coil bobbin is a problem that has become a manufacturing bottleneck.

Means for Solving the Problems> The structure of the present invention for achieving the objects will be explained using FIG. 1 and FIG. 2. 1) It has a structure in which three members, the edge part (2) and the voice coil bobbin (3), are integrally molded.

Since the present invention has such a structure, engineering plastic such as polyether sulfone or PEEK is injected from the pinpoint gate injection port provided in the center of the diaphragm using the pinpoint gate mold. 2
When injection molding is performed by injecting a molten liquid at a temperature of 00° C. or higher, a molded product with a thickness of about 0.05 am can be produced in the step. In this molded product, the diaphragm (1), edge portion (2), and voice coil bobbin (3) are integrally formed with verticality and concentricity on the order of 0.001 mm.

Therefore, there is no need to bond the diaphragm (1) and the voice coil bobbin (3) together.

<Example> Embodiments of the present invention will be described below based on the drawings.

The embodiment shown in FIG. 1 is a vibrating member made of PES (polyether sulfone), an engineering plastic, melted at about 200°C or higher and injection molded using a bottle point gate mold. 25II
It has standard dimensions of Ilφ.

The thickness of each part is about 0.05zi+ and is constant at each part.

Since the heating deformation is small, even if a relatively large current flows through the voice coil (4) with a large input and the temperature rises due to Joule heat, the deformation is small, so the narrow magnetic space 11! Even if the voice coil (4) vibrates within the gap (5), the voice coil (4) will not rub against the gap (5) because of its strong shape-retaining force.

The voice coil bobbin (3) normally requires a glue margin (14) to attach a pool of adhesive to the tip and a gluing process, resulting in low finishing accuracy, but in the present invention, the molten synthetic resin of each component is fluidized. and mix to form an integrated molded product, so there is no need for a bonding process using a separate adhesive or adhesive (14), which saves labor and creates a molded product with extremely high finishing accuracy. .

Therefore, the finished dimensional accuracy of the molded product is on the order of 0.01 scrap, so even after winding the voice coil (4),
Since high accuracy can be maintained, the utilization efficiency of the magnetic gap (5) can be increased, and the sound pressure frequency characteristics also become flat, with the level of the treble range and the treble range limit f rising, as shown in the solid line graph in Figure 3. Become.

Therefore, the speaker implementing the product of the present invention has a magnetic air gap (5
) can be made smaller, which increases the efficiency of permanent magnet use, significantly improves the acoustic radiation efficiency of the speaker, and reduces vibration conduction loss at the base of the voice coil bobbin (3), which improves high-frequency reproduction. This has the advantage of being abundant.

Although the present invention has been described above in the case where it is applied to a dome-shaped diaphragm, it is also possible to apply it to a so-called cone-shaped diaphragm in which the vibrating portion is formed in a cone shape, which has only a dome shape.

Although the embodiments considered to be representative of the present invention have been described above, the present invention is not necessarily limited to the structure of these embodiments. It can be implemented with appropriate modification within the scope of achieving the following effects.

<Effects of the Invention> As is already clear from the above description, the present invention uses materials such as expensive engineering plastics, which have high-quality properties that have not been used as raw materials for conventional speakers, and produces molded products. Taking advantage of axial symmetry,
We have come to expect the remarkable effect of being able to encapsulate the center of a bottle point gate mold, which is a speaker vibration member that skillfully combines characteristics and processing methods not found in other molds. be.

Also, the mark on the bin point gate of the molded product is 0.5
Since the diameter is about zzφ, it can be easily finished using a simple tool such as nippers and a file.

[Brief explanation of the drawing]

, Fig. 1 is a partially cutaway perspective view showing the structure of a vibrating section to which the present invention is applied, Fig. 2 is a sectional view of a soft dome-shaped speaker to which the present invention is applied, and Fig. 3 is a speaker to which the present invention is applied. and a frequency characteristic diagram of a conventional speaker, and FIG. 4 is a cross-sectional view of the conventional speaker. In the figure, (1) is a diaphragm, (2) is an edge portion, and (3) is a voice coil bobbin. Figure 2

Claims (1)

[Claims] Injection engineering plastic diaphragm (1), edge part (2) and voice coil bobbin (3)
) A speaker vibration member characterized by a structure in which three parts are integrally molded.