JPH02268596A - Low leak magnetic flux type speaker - Google Patents

Abstract

PURPOSE:To decrease the number of components and the production processes by using a material formed by mixing magnetic material powder with resin, applying a metallic mold with a magnetic field at the time of molding and arraying the magnetic material powder so that a magnetic circuit is covered, and forming it as a shielding cover. CONSTITUTION:The magnetic circuit 24 constituted by sandwiching a magnet 21 between an upper plate 22 and a lower plate 23 is molded out of resin wherein the magnetic material powder such as iron powder is mixed integrally. At time time, the ferromagnetic field is applied to the metallic mold for molding and the magnetic powder is so arrayed in a shape for covering the magnetic circuit 24, i.e., the same shape with the shielding cover, thus forming the shielding cover 31. Consequently, the number of components and the production processes can be decreased and the inexpensive low leak magnetic flux type speaker can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a low leakage flux type speaker used in various audio equipment and video equipment.

2. Description of the Related Art A conventional low leakage magnetic flux type speaker of this type has a configuration as shown in FIG. That is, the diaphragm 6 is bonded to the periphery of a frame 6, which is constructed by integrally molding a magnetic circuit 4 made of resin by sandwiching a magnet 1 between an upper plate 2 and a lower plate 3. The voice coil 7 that drives the diaphragm e is held at its middle by a damper 8, and is coupled to fit into the magnetic gap 9. The dust cap 10 was adhered to form a speaker body. Furthermore, a shield cover 11 made of a magnetic metal such as an iron plate is bonded to cover the entire magnetic circuit 4 to form a low leakage magnetic flux type speaker.

Problems to be Solved by the Invention However, in conventional low-leakage magnetic flux speakers of this type, a vibration system is assembled into a frame 6 that is molded by integrating a magnetic circuit 4 consisting of a magnet 1 and upper and lower plates 2.3. However, in order to take measures against magnetic flux leakage, a shield cover 11 that covers these magnetic circuits 4 had to be added to the speaker body in a later process, and the unit price of the shield cover 11 and its These low-leakage magnetic flux speakers have had the problem of being extremely costly due to the additional labor costs for gluing them to the speaker body, the increased number of parts, and the increased production process.

The present invention solves these conventional problems and provides a low-leakage flux type speaker that is inexpensive in terms of cost by reducing the number of parts and production processes.

Means to Solve the Problems In order to solve the above problems, the present invention has a structure in which a shield cover is bonded in a post-process to a speaker body in which a vibrating component is assembled to a molded frame that integrates a magnetic circuit consisting of a magnet and an upper and lower plate. Instead of a process of molding the magnetic circuit, a magnetic material is mixed into the resin used to mold the magnetic circuit, and a magnetic field is applied to the mold that is integrally molded with the frame, and the magnetic material powder is arranged in a shape that covers the magnetic circuit, creating a shield. The structure is such that it is formed as a cover.

Effects By adopting the above configuration, there is no need to use a component called a shield cover as in the past, and due to the manufacturing method, there is no need for the process of gluing the shield cover to the speaker body in the subsequent process. It is possible to reduce the number of parts of the cover and the number of man-hours required to bond the shield cover to the speaker body, and it is possible to reduce the number of parts and the production process, that is, to reduce material costs and labor costs at the same time.

Embodiment Hereinafter, a low leakage flux type speaker which is an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, when a magnetic circuit 24 formed by sandwiching a magnet 21 between an upper plate 22 and a lower plate 23 is molded into a resin mixed with magnetic material powder such as iron powder. A strong magnetic field is applied to the molding die to form a shield cover 31 by arranging magnetic material powder in a shape that covers the magnetic circuit 24, that is, in the same shape as the shield cover. Vibration plate 26
A voice coil 27 for driving this diaphragm 26 is held in the center by a damper 28 at its middle part.
The diaphragm 2
A dust cap 3o is adhered to the surface of the speaker 6 to form a low leakage magnetic flux type speaker.

By adopting such a configuration, it is possible to simultaneously reduce the number of parts of the shield cover and reduce the number of man-hours for adhering it to the speaker body.

Effects of the Invention As described above, the present invention provides a speaker structure and its production in which a conventional magnetic circuit is integrally molded with 7 frames, a vibrating component is assembled as a speaker body, and a shield cover is bonded in a post-process. Compared to the construction method, in the production process where the magnetic circuit is integrated with the frame and molded, magnetic material powder is mixed into the resin, and a magnetic field is applied to the mold during molding to cover the magnetic circuit. By arranging the powder and forming it as a shield cover, it is possible to reduce the number of parts for the shield cover and reduce the number of man-hours required to bond the shield cover to the speaker body.This reduces the number of parts and the production process, which means lower material costs. It is possible to simultaneously reduce labor costs and provide an inexpensive low-leakage magnetic flux speaker.
Its industrial value is enormous.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a low leakage magnetic flux type speaker according to an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional low leakage magnetic flux type speaker. 21... Magnet, 22... Upper plate, 23... Lower plate, 24...
・・Magnetic circuit, 25・・・・7 rem, 26・River・
・Vibration plate, 2-r...Voice coil plate 28...
damper, 29...magnetic gap, 30...
...Dust cap, 31...Shield cover made of magnetic material powder Name of agent Patent attorney Shigetaka Awano Haga 1 person Figure 29 Ishimasahoki f"7 Pugo + Mo warm TLI!! Station J Figure 2

Claims (1)

[Claims] A frame in which a magnetic circuit formed by sandwiching a magnet between an upper plate and a lower plate is integrally molded with resin mixed with magnetic material powder, and a shield cover is formed with the magnetic material powder, and a peripheral edge of this frame. A diaphragm is glued to the diaphragm, and a voice coil that fits into the magnetic gap of the magnetic circuit is coupled to this diaphragm.
A low leakage magnetic flux speaker with a dust cap glued to the front of the diaphragm.