JPS59210791A - Diaphragm for speaker - Google Patents

Abstract

PURPOSE:To attain high rigidity with light weight by using a core member with a high foaming rate, forming plural minute holes in a perpendicular direction, coating an adhesives to the core member so as to allow the adhesives to be impregnated in the minute holes and adhere a surface member to the surface of this core member. CONSTITUTION:A disc made of polystylene foaming body is used as the core member 1 and the minute holes 6 at an interval of 3mm. and having a diameter of 2mm.phi in the perpendicular direction are formed on the entire face. The adhesives 3, 3' made of acrylic system copolymer synthetic resin solution are coated on the surface of the core member 1 formed with lots of minute holes 6. In this case, the adhesives 3, 3' are impregnated in the minute holes 6 and the adhesives 3, 3' adhered to the wall face of the minute holes 6. Immediately after coating the adhesives 3, 3' or a prescribed time, the surface members 2, 2' made of aluminum foil having the thickness of 50mu are adhered to form a diaphragm. The adhesive strength of the surface member made of the foaming body to the core member is increased by this method, the strength as the diaphragm is improved and the durability in assembling the diaphragm to a speaker is improved considerably.

Description

DETAILED DESCRIPTION OF THE INVENTION An object of the present invention is to provide an inexpensive speaker diaphragm that is lightweight and has high bending rigidity.

Conventionally, planar speaker diaphragms have been made using organic polymer foam as a core material and having a surface opening with a high modulus of elasticity on the surface of the core material, or as a core material made of nicum, feather core, etc. As a diaphragm, a diaphragm is used in which a surface material with a high elastic modulus is provided on the surface of this core material.

In the conventional planar diaphragms made of foam mentioned above, rigidity has been obtained by molding the foam into a cone shape, or methods have been used to obtain rigidity by making the foaming ratio relatively small, but are they important? It has the disadvantage of being small and inefficient when used as a speaker. - If a foam with a high expansion ratio is used for the painting, the cell strength of the foam is weak, and even if the surface layer is firmly bonded, cell rupture will occur and the surface material will peel off. There was a problem with long-term reliability/ξ, but Teimei eliminates the above-mentioned conventional drawbacks and provides a light-weight and highly rigid speaker diaphragm. "Use a sea urchin sea urchin core material and form multiple holes in the thickness direction, and the adhesive will also enter into these pores": Apply adhesive to the sea urchin core material, and apply a surface material to the surface of this core material. It is something to be glued.

Thermoplastic material (d
Polystyrene, polyacrylic acid ester, or their copolymers are available, and thermosetting materials include phenol, urea,
Can be used with epoxy, polyurethane, etc. However, in order to keep the product lightweight, it is necessary to increase the foaming ratio as much as possible.

When the expansion ratio is increased, the cell strength rapidly decreases in inverse proportion to the expansion ratio. Even if the surface layer is firmly adhered to such a core material, the surface layer often peels off due to cell rupture of the base core material.

The present invention eliminates the above-mentioned conventional drawbacks, increases the adhesive strength of the surface material to the core material, improves the strength of the diaphragm, and greatly improves the input resistance of the speaker. An embodiment of the present invention will be described in comparison with a conventional train.

[Conventional example]

FIG. 1 shows a conventional speaker diaphragm.

In FIG. 2, 1 is a core material, and this core material 1 is made of polystyrene foam having closed cells with an expansion ratio of 50 times, and has a disk shape with a thickness of 0 mm and a diameter of 2 ocrn. 2, 2' are surface materials adhered to the surface of the core material 1 with an adhesive 3, 3' made of acrylic co-offshore material C], and these surface materials 2, 2' are aluminum foil with a thickness of 50 μm. . The thickness of the adhesive layer of the adhesive 3.3' is approximately 60 μm. In the first drawing, 41d, 19111111φ
This coil bobbin 4 is bonded to the center of the lower surface of the diaphragm with Evokin resin adhesive. 5 is a voice coil.

[Example 1] Core material 1 made of the same material and the same shape as the conventional example above, that is, made of polystyrene foam with a foaming ratio of 60 times and a thickness of 7.0
Using a disk with a diameter of 20 cm and a diameter of 20 cm, pores 6 having a diameter of 2 in the thickness direction were formed on the entire surface of the core material 1 at intervals of 3 as shown in FIG. An adhesive 3°3' made of an acrylic copolymer resin solution is applied to the surface of the core material 1 in which a large number of pores 6 are formed. In this case, the adhesives 3, 3' also enter the pores 6, and the adhesives 3, 3' also adhere to the walls of the pores 6. Immediately after applying the adhesive 3, 3' or after heating after a certain period of time has elapsed, the surface material 2, 2' made of aluminum foil having a thickness of 50 μm is adhered to form a diaphragm.

[Example 2] As shown in FIGS. 3A, B, C, and D, non-penetrating pores 7 were formed on the entire surface of one side of the core material 1 at intervals of 3 mm, and adhesive 3 was applied in the same manner as in Example 1. , 3', the surface layer 2, 2 is applied to the surface of the core material 1.
′ is glued to form a diaphragm.

The following table shows the above conventional example and Example 1. Example 20 Surface material 2,2
The results show the peel strength (using a sample with a width of 15 mm) and the results of a tensile strength test by fixing a coil bobbin 4 to each diaphragm and chucking the coil bobbin 4.

As is clear from the above table, in the present invention, +1
The adhesive also enters the +l11 hole, increasing the adhesion area of the adhesives 3 and 3', which increases the strength of the surface materials 2 and 2' from the core material 1, and also makes the coil bobbin 4 tensile and 1 /Even in this case, in the conventional example, the table is 1m14' at 2800y.
A' 2 , 2' peeling 1jfI sifc (In contrast to DK, according to Examples 1 and 2, the diaphragm was destroyed at 70001 without peeling of the surface 4'A2r'').

FIG. 4 and FIG. 5 Q show other embodiments of the present invention,
Pore6. A coil bobbin 4 in which γ is formed on the entire surface of the core material 1.
is formed locally in the area to be bonded to increase the strength of this area.

The present invention has the above configuration, and according to the present invention, the adhesive strength of the surface material to the core material made of foam is increased, the strength of the diaphragm is improved, and the resistance when inserted into a speaker is improved. This has the advantage of greatly improving input power and improving reliability during long-term use.

kThe present invention is not limited to the solid line side shown in -1-,
It can be used for 1m diaphragms of any shape (rectangular, square, etc.).

[Brief explanation of drawings]

Figure 1 A phase: Top view of the core material of a conventional speaker diaphragm,
FIG. 1B is a cross-sectional view of the same, FIG. A top view of the core material of a speaker diaphragm, Figure 2B is a sectional view of the same, Figure 2C is a sectional view of the same diaphragm, and the second diagram is a sectional view of the same diaphragm with a coil bobbin bonded to it. , FIG. 3A is a top view of another embodiment of the present invention, FIG. 3B is a sectional view of the same, FIG. 3C is a sectional view of the same diaphragm, and the third diagram shows a coil bobbin attached to the same diaphragm. 4 and 6 are cross-sectional views of still other embodiments of the present invention, respectively. 1... core material, 2, 2'... i... surface material, 3, 3
'...Adhesive, 4...Coil bobbin, 6...
...Voice coil, 6.7...Pore. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3

Claims (4)

[Claims] (1) Multiple pores are formed in the core material made of foam in the thickness direction, adhesive is applied to the surface of the core material so that the adhesive enters the pores, and the surface material is covered with this adhesive. A speaker diaphragm bonded to a core material. (2) A diaphragm for a speaker according to claim 1, wherein pores are formed through the core material. (3) A diaphragm for a speaker according to claim 1, wherein pores that do not penetrate are formed in the core material. (4) The speaker diaphragm according to claim 1, wherein a plurality of pores are locally formed in the core material.