JPS62149298A - Speaker and its manufacture - Google Patents

Abstract

PURPOSE:To aim at rationalization by the reduction of man-hours making a resin frame and a resin magnet in one body, and to reduce the failure rate of an iron power having feature of rustless, light, and strong by molding the frame and the magnet with a dissimilar material in one body utilizing a thermoplastic resin. CONSTITUTION:The temperatures of a movable and a fixed metallic molds 5 and 6 are set between 200-300 deg.C, and a thermoplastic resin 7 is injected from several places of the movable metallic mold 5. As the resin 7, a nylon, a polyacetal or a glassfiber, and a carbon fiber are used. Also, from several places of the fixed metallic mold 6, a mixed material 8 of the thermoplastic resin and a magnetic powder is injected. As the magnetic powder, a ferrite or a samarium cobalt, etc., is utilized, and it is recommended that a mixing ratio between the resin is set at a weight distribution ratio of 80%-90% to 20%-10%. An injection condition is set so that the mixing material 8 flows in the direction of the movable mold 5, and the disappear of a magnetic flux at a magnetic ring by the flow of the resin 7 to the fixed mold 6 can be prevented. When the resin and the mixing material flows in both molds 5 and 6, a magnetic field is applied in parallel with the moving direction of the mold 5, and a magnetic ring 3 and a frame 1 are molded in one body.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a speaker used in various types of audio equipment and a method for manufacturing the same.

2. Description of the Related Art Conventionally, the materials of the frame and magnetic circuit used in this type of speaker and the method of joining the two are shown in FIGS. 5 to 7. That is, in FIG. 5, a frame 10 made of R% gold and a metal upper plate 11 are joined by arc welding 12.

In addition, in Fig. 6, the metal center pole plate 1
An adhesive 15 is applied to the upper part of the magnet ring 4, and then a sintered magnet ring 13 is bonded while being pressed and dried. Furthermore, in FIG. 7, an adhesive 15 is applied to the upper part of the sintered magnet ring 13, and then the upper plate 11 with the frame 10 is adhered while being pressed and dried, and a speaker is obtained by the above steps.

Problems to be Solved by the Invention However, in such conventional speakers, as shown in FIGS. 14. There is a joining process with the upper plate 11, but in the former case, there are problems in that it is dangerous to handle, and moreover, debris may enter the gap 16 during arc welding, easily leading to product defects. In the latter case, since adhesive 15 is used, there is a problem that the adhesive strength is greatly affected by the coating amount, coating position, drying conditions, etc., and the reliability is low. Furthermore, since a medium called adhesive 15 is required for bonding, there are problems in that the number of man-hours increases and time is consumed.

Furthermore, if the material of the sintered magnet song 13 is ferrite, it is heavy, hard, and brittle, which causes the problem of easily producing iron powder defects. Since the adhesive 15 serves as a medium for joining the upper plate 11, there is also the problem that magnetic permeability is reduced.

Therefore, the present invention solves the above-mentioned problems, and allows the frame and the magnet ring to be easily integrally molded without using conventional adhesives or welding as a joining means. The object of the present invention is to provide a speaker that can be easily joined together and is excellent in terms of quality and characteristics, and a method for manufacturing the same.

Means for Solving the Problems In order to solve the above problems, the speaker of the present invention includes a resin magnet ring formed by applying a magnetic field to a mixed material of thermoplastic resin and magnetic powder, and a thermoplastic resin magnet ring similar to that described above. It is integrally molded with a frame made of resin.

Further, in the method of manufacturing a speaker according to the present invention, a mixed material of thermoplastic resin and magnetic powder is injected from a first direction for molding a resin magnet ring, and a thermoplastic resin similar to the above is injected from a second direction for molding a frame. After injection from the direction, a magnetic field is applied to the mixed material to integrally mold the resin magnet ring.

Effects According to the means of the present invention, the frame and the magnet ring can be easily integrated without using adhesives, welding, etc., and since thermoplastic resin is used, joining by heat welding is possible. Magnetic permeability ・It can be made even lighter without lowering the magnetic rate, and it can also be made durable and hard to chip.

EXAMPLE Below, a method of integrating a frame and a magnet ring and a method of joining a magnetic circuit part in an example of the present invention will be described. FIG. 1 is a sectional view of a speaker according to the present invention, and FIGS. 2 to 4 are manufacturing process diagrams thereof.

As shown in FIG. 2, the movable mold 5 is a mold that can mold a frame, and the fixed mold 6 is a mold that can mold a magnet ring.The movable mold 5 and the fixed mold 6 are combined. I'll keep it. The mold temperature at this time was 200
Keep the temperature at ~300°C.

Next, the thermoplastic resin 7 is injected from the second direction at several locations on the movable mold 5. As the thermoplastic resin 7, nylon, polyacetal, etc. can be used, or a composite of these with a fibrous reinforcing material such as glass fiber or carbon 41i can be used. At the same time, the same mixed material 8 of thermoplastic resin and magnetic powder as described above is injected from the second direction at several locations on the fixed mold 6. As the magnetic powder of this mixed material 8, ferrite, samarium cobalt, etc. can be used, and the mixing ratio of these magnetic powders to thermoplastic resin is preferably 80 to 90% to 20 to 10% by weight.

At this time, the injection conditions are such that the mixed material 8 flows toward the movable mold 5, and the thermoplastic resin 7 flows toward the fixed mold 6.
This prevents the magnetic field from flowing into the side and preventing the formation of a magnetic field in the magnet ring.

Once the thermoplastic resin 7 and the mixed material 8 have sufficiently flowed into the movable mold 5 and the fixed mold 6, a magnetic field is then applied in parallel to the moving direction of the movable mold 5. As a result, the anisotropic resin magnet ring 3 with a high energy product and the frame 1 are integrally molded. Next, the movable mold 5 is separated from the fixed mold 6, and the molded product is not removed from the mold.

FIG. 3 shows a molded product, and as shown, the resin magnet ring 3 and the frame 1 are integrally molded, and a plurality of convex portions 9 are integrally molded on the upper and lower parts of the resin magnet ring 3, respectively. ing.

FIG. 4 shows the process of attaching the plate 4 with center pole and the upper plate 2. Both plates 2.4 have through-holes through which the protrusions 9 can be inserted, and the tips of the protrusions 9 are made to protrude from these through-holes, and the protrusions are thermally welded using a heater 10. As a result, both plates 2.4 are fixed to the resin magnet ring 3. As a result, the plates 2.4 and the resin magnet ring 3 are directly bonded to each other without using a conventional adhesive medium for bonding, thereby preventing a decrease in magnetic permeability.

Effects of the Invention As described above, according to the present invention, by integrally molding the resin frame and the resin magnet from different materials using thermoplastic resin, it is possible to achieve rationalization by reducing the number of man-hours due to integration. Furthermore, in terms of quality and performance, the characteristics of resin are that it does not rust, is lightweight, durable, and does not easily chip, making it possible to reduce defects in iron powder.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a speaker in an embodiment of the present invention;
2 to 4 are diagrams showing the manufacturing process in one embodiment of the present invention, and FIGS. 5 to 7 are diagrams showing the manufacturing process in a conventional example. 1...Frame, 3...Resin magnet ring, 7
...Thermoplastic resin, 8...Mixed material agent Yoshihiro Moriki/---Flame L-m3-r#n company Geov L#/) Guar°-Nu1 Plastic-L"1787 n' M, 9-11 mixed N house Figure 2 Figure 4 Figure 5

Claims (1)

[Claims] 1. A resin magnet ring formed by applying a magnetic field to a mixed material of thermoplastic resin and magnetic powder and a frame made of the same thermoplastic resin as described above are integrally molded. Featured speakers. 2. The resin magnet ring has the upper and lower parts,
2. The speaker according to claim 1, further comprising a convex portion for fixing the plate with center pole and the upper plate by heat welding. 3. Claims characterized in that the thermoplastic resin is nylon or polyacetal, or a composite of these with a fibrous reinforcing material as required, and the magnetic powder is samarium cobalt or ferrite. The speaker according to item 1 or 2. 4. After injecting a mixed material of thermoplastic resin and magnetic powder from a first direction for molding a resin magnet ring, and injecting the same thermoplastic resin as above from a second direction for molding a frame, A method of manufacturing a speaker, comprising integrally molding the resin magnet ring and the frame by applying a magnetic field to a mixed material. 5. By forming convex portions on the upper and lower parts of the resin magnet ring, passing these convex portions through the holes in the plate with center pole and the upper plate, and then thermally welding the tips of the convex portions to both of the plates, 5. The method of manufacturing a speaker according to claim 4, wherein both the plates are fixed to a resin magnet ring. 6. Claims characterized in that the thermoplastic resin is nylon or polyacetal, or a composite of these with a fibrous reinforcing material as required, and the magnetic powder is samarium cobalt or ferrite. The method for manufacturing a speaker according to item 4 or 5.