JPS62265899A - Magnetic circuit for speaker - Google Patents

Abstract

PURPOSE:To fix cracks and chips with resin and to prevent fine magnets from attaching to a magnetic gap by injecting and forming resin between the inner diameter of a ring-like magenet and the central hole diameter of an upper plate and in a space enclosed by upper and lowr plate walls. CONSTITUTION:The upper plate 5 with a center hole for constituting the mag netic gap 7 is jointed on the upper surface of the ring-like magnet 4, and a lower plate 6 provided with a radial groove 10 is jointed on a surface contacting the lower surface of the ring-like magent 4 having a center pole 6a in the center. A periphery part is covered with the resin 8 and fixed. Simultaneously the resin 9 is injected and formed between the inner diameter of the ring-like mag net 4 and the centeral hole diameter of the upper plate 5 through the groove 10 provided on the lower plate 6. Thus such trouble can be prevented that the crack and chip of the magnet, which occur on the inner diameter side of the ring-like magnet, shift and attach to the magnetic gap.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a magnetic circuit for speakers used in various audio equipment.

2. Description of the Related Art Conventionally, a magnetic circuit for a speaker of this type has a structure as shown in FIG. That is, the ring-shaped magnet 1 had a structure in which an upper plate 2 having a center hole constituting a magnetic gear knob was adhered to the upper surface, and a lower plate 3 having a center pole 3a at the center was adhered to the lower surface.

Problems to be Solved by the Invention However, with the above-described configuration of the magnetic circuit for a speaker, if cracks or chips occur on the inner corner or wall of the ring-shaped magnet 1, the minute magnet will be in the vicinity of the magnetic gap. There was a problem in that when it was attached and incorporated as a speaker, it would interact with the voice coil and generate abnormal noise when it was operated.

Therefore, the present invention provides a magnetic circuit for a speaker to prevent minute magnets such as cracks and chips of the magnet generated inside the inner diameter of the ring-shaped magnet from migrating and causing noise in the magnetic gap. It is something to do.

Means for Solving the Problem In order to solve this problem, the present invention provides grooves radially from the base of the center ball on the lower plate surface that contacts the bottom surface of the ring-shaped red sea bream and the cut, and a magnetic circuit. The outside is covered with resin and fixed, and at the same time, a resin layer is formed through this groove in a space between the inner diameter of the ring-shaped magnet and the center hole diameter of the upper plate and surrounded by the upper and lower plate walls.

Function: As mentioned above, the resin is formed in the space inside the magnetic circuit through the groove provided on the lower plate surface that contacts the lower surface of the ring-shaped red sea bream soto, which prevents cracks and chips that occur on the inner corners and walls of the ring-shaped magnet. This will prevent these minute magnets from migrating and adhering to the magnetic gap, thereby preventing abnormal noise from coming into contact with the voice coil.

Example Below, a magnetic circuit for a speaker in an example of the present invention (
(explain about.

As shown in Figure g1, an upper plate 6 having a center hole for forming a magnetic gap 7 is attached to the upper surface of the ring-shaped magnet 4, and a center pole is attached to the lower surface at the center as shown in Figures 2a and b. 6a and provided with radial grooves 10 on the surface that contacts the lower surface of the ring-shaped magnet 4, the outer periphery of the lower plate 6 is covered and fixed with resin 8, and at the same time, the lower plate 6 is provided with a radial groove 10. Resin 9 is injected throughout the groove 10, between the inner diameter of the ring-shaped magnet 4 and the center hole diameter of the upper plate 5, and also in the space surrounded by the upper and lower plate walls.

Effects of the Invention As described above, the present invention provides a ring-shaped magnet by injecting resin into the space between the inner diameter of the ring-shaped magnet constituting the magnetic circuit and the center hole diameter of the upper plate and surrounded by the upper and lower plate walls. By fixing cracks and chips that occur on the inner corners and walls of the magnet with resin, and preventing these minute magnets from migrating and adhering to the magnetic gap, the connection with the voice coil when installed and operated as a speaker is prevented. It has the effect of preventing the generation of abnormal noise due to contact, and is of great industrial value.

[Brief explanation of drawings]

FIG. 1 is an enlarged cross-sectional view of essential parts of a magnetic circuit for a speaker according to an embodiment of the present invention, and FIGS. FIG. 3 is a sectional view of a conventional speaker magnetic circuit. 4...Ring magnet, 6...Upper plate, 6...Lower plate, A...
...Magnetic gap, 8...Resin, 9...
Resin, 10... Groove. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2: Ward J -j

Claims (1)

[Claims] An upper plate having a center hole for forming a magnetic gap is bonded to the upper surface of the ring-shaped magnet, and a center pole is attached to the lower surface of the ring-shaped magnet. A lower plate having one or more grooves in a radial manner is joined, and its outer circumference is covered with resin to fix it, and at the same time, through the groove provided in the lower plate, between the inner diameter of the ring-shaped magnet and the center hole diameter of the upper plate, and between the upper and lower sides. A magnetic circuit for a speaker is formed by injecting resin into the space surrounded by the plate wall.