JPS6035120Y2 - Buzzer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a buzzer that vibrates a magnetic metal diaphragm through magnetic interaction between an electromagnet and a permanent magnet provided to surround the electromagnet.

FIG. 1 shows a conventional example of this type of buzzer.

As shown in the figure, in the conventional buzzer, an iron core 2 wound with a coil 1 is erected on a disk-shaped yoke 3, and the yoke 3
A cylindrical permanent magnet 4 is magnetically attracted to the outer peripheral edge of the
Furthermore, since the structure is such that a ring-shaped spacer 5 and a diaphragm 6 made of a magnetic metal material or the like with a weight 7 attached to the center are successively stacked on the open end 4a of the permanent magnet 4, the following drawbacks occur. was there.

(a) Since the vibration motion of the diaphragm 6 depends on the gap G1 formed between it and the tip surface of the iron core 2, the distance of the gap G□ must be strictly controlled to a predetermined value.

However, with the structure shown in Fig. 1, the yoke 3,
Since the processing errors of the permanent magnet 4 and the spacer 5 and the assembly errors of the contact surfaces of each part are accumulated, the position of the diaphragm 6 is not constant and the distance of the air gap G1 fluctuates, resulting in variations in sound quality, volume, etc. It will happen.

(b) For this reason, in the past, the iron core 2 was screwed onto the yoke 3, or the yoke 3 was screwed onto the permanent magnet 4, as shown in FIG. 1, and the gap G□ was set by adjusting the amount of screwing. It was mandatory to set it to a value.

However, the distance of the gap G1 needs to be set to a very small value of about 100±10 μ, and it is not necessarily easy to set the gap G1 to a predetermined value even when using the above-mentioned adjustment means.

Moreover, with the above-described structure, the yoke 3, the iron core 2, or the permanent magnet 4 must be machined with screws, resulting in an increase in the number of processing steps and a disadvantage in that the cost becomes high.

(c) The permanent magnet 4, yoke 3, and iron core 2 must be manufactured individually by machining heavy magnetic metal materials, which increases the weight and size of the entire buzzer.

Since this type of buzzer is used by being incorporated into small devices such as pagers and watches, it must be made as light and compact as possible, and conventional buzzers cannot adequately meet this requirement. I can't.

B) The buzzer shown in FIG. 1 is normally used by fitting it into an outer case made of non-magnetic material such as synthetic resin.

However, it is actually impossible to fit the buzzer completely tightly into the outer case, and a gap is created between the outer surface of the permanent magnet 4 or yoke 3 and the outer case, which hinders the sounding operation of the buzzer. Sometimes, a so-called buzzing sound is generated, which deteriorates the sound quality.

The present invention eliminates the above-mentioned drawbacks of the conventional technology, allows the gap distance between the diaphragm and the iron core to be controlled with high precision without the need for an adjustment mechanism, provides good vibration sound quality, and is inexpensive. The purpose of the present invention is to provide a small and lightweight buzzer.

In order to achieve the above object, the present invention has an electromagnet, a diaphragm that faces the end face of an iron core constituting the electromagnet via a gap, and a support surface that supports the diaphragm, and has a bottomed cylindrical shape. a formed storage case, an iron core integrally erected on the bottom of the storage case, and a washer made of a magnetic material that is passed through the iron core and placed on the inner surface of the bottom of the storage case; A permanent magnet is arranged on the washer so as to surround the electromagnet.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The content of the present invention will be specifically explained in detail below with reference to the accompanying drawings, which are examples.

FIG. 2 is a sectional view of the buzzer according to the present invention, and FIG. 3 is an exploded perspective view thereof.

In the figure, reference numeral 8 denotes a storage case formed into a cylindrical shape with a bottom using a non-magnetic material such as synthetic resin.

The upper opening edge of the storage case 8 is provided with an annular step 8a.

9 is an iron core around which a coil 10 is wound.

The iron core 9 is integrally erected approximately on the axis of the bottom portion 8b of the storage case 8.

The position of the tip end face 9a of the iron core 9 is determined to be lower than the step portion 8a by a height G2.

Note that the storage case 8 and the iron core 9 are integrally molded, the details of which will be described later.

11 is a cylindrical permanent magnet.

The permanent magnet 11 is provided along the inner circumferential surface of the storage case 8 so as to surround an electromagnet consisting of an iron core 9 and a coil 10, and its tip end surface 11a is positioned so as to be lower than the stepped portion 8a by a height G3. It is stipulated in

Although the permanent magnet 11 may be a metal permanent magnet, a magnet made of a highly elastic magnetic material such as a rubber silver layer or a resin magnet is more preferable.

Rubber magnets or resin magnets have high flexibility and elasticity, so even if they are manufactured with a diameter slightly larger than the inner diameter of the storage case 8, they can be easily pushed into the storage case δ, and after insertion, they have their own elasticity. This is because it comes into close contact with the inner circumferential surface of the storage case 8 without creating a gap, thereby preventing the generation of rattling noise.

12 is a diaphragm made of a thin disc-shaped magnetic metal material or the like.

The diaphragm 12 is supported by the stepped portion 8a of the storage case 8 as a support surface.

As mentioned above, the step portion 8a has a height G2 higher than the tip surface 9a of the iron core 9.
G3 is higher than the end surface 11a of the permanent magnet 11.
only.

Therefore, when the diaphragm 12 is supported by the step portion 8a, the lower surface 12a of the diaphragm 12 and the tip surface 9 of the iron core 9
a and the end surface 11a of the permanent magnet 11, there is a gap G2. G3 is formed.

Due to the existence of the gap G3, the distal end surface 9a of the iron core 9 and the diaphragm 1
The gap G2 between the diaphragm 1 and the diaphragm 1 in the storage case 8 is
It is determined only by the position of the distal end surface 9a of the iron core 9 with respect to the supporting surface of the permanent magnet 2, that is, the step portion 8a, and is completely unrelated to processing errors and assembly errors of the permanent magnet 11.

That is, in the buzzer according to the present invention, the storage case 8
By simply managing the position of the tip end face 9a of the iron core 9 in a predetermined relationship with respect to the stepped portion 8a, the distance of the gap G2, which is the most important in this type of buzzer, can be easily maintained at a constant value. be.

The gap G2 can be made constant by molding the storage case 8 and the iron core 9 together.

13 is a washer made of magnetic material.

The washer 13 passes through the iron core 9 and attaches to the bottom 8 of the storage case 8.
It is placed on the inner surface of b.

A permanent magnet 11 is placed on this washer 13.

With such a structure, the washer 13 is made independent from the storage case 8 and the iron core 9, and the magnetic circuits Lt and L2 surrounding the iron core 9, the diaphragm 12, the permanent magnet 11, and the washer 13 are maintained while eliminating the influence on the air gap G2. The magnetic resistance can be reduced and the performance of the buzzer can be improved.

Moreover, since the washer 13 is supported by the bottom part 8b of the storage case 8, it does not need to be thick and strong like the yoke 3 shown in FIG. 1, and can be easily manufactured by pressing a thin plate material. .

Therefore, the processing of the washer 13 itself becomes easy, and this contributes to making the entire buzzer thinner.

Furthermore, when inserting the washer 13 into the storage case 8,
Assembling is made very easy because it is only necessary to insert and fit the iron core 9 into the center hole 13a (see FIG. 3).

14 is a printed circuit board, and is provided with a button for relaying the lead wire of the coil 10 and lead terminals 15 and 16.

FIGS. 4A, B, C and D are concrete explanatory diagrams of mold forming.

In the figure, A is the male type and B is the female type.

The male type A is provided with a stepped portion 8'a corresponding to the stepped portion 8a of the storage case 8 on its outer periphery, and a recessed groove 9' into which the iron core 9 is inserted is provided in the center thereof.

The axial distance between the bottom surface 9'a of the groove 9' and the stepped portion 8'a is set to be approximately equal to the gap G2.

In addition, at the rear end of the core 9 to be inserted into the groove 9',
A protrusion 9b is provided in a protruding manner, and a crushing margin is provided at the tip of the protrusion 9b to be crushed by the female mold B during molding.

That is, in FIG. 4A, the end surfaces a of the male mold A and the female mold B,
When the position of the bottom surface C of the female mold B is C' when they are brought into engagement contact with each other, the tip surface 9a is the bottom surface 9' of the groove 9'.
The protrusion 9b of the iron core 9 that is brought into contact with the iron core 9 is made to protrude in the direction of the female die B by a length 1 beyond the position C', and this length 1 is used as the crushing margin.

Therefore, when the core 9 is inserted into the groove 9' of the male mold A and the male mold A and the female mold B are pushed forward until their end faces a and b come into pressure contact with each other, the protrusion 9b of the iron core 9 will move into the groove 9'. Due to the pressing force applied between the bottom surface 9'a of the mold B and the bottom surface C of the female mold B, the mold B is crushed by a length of 1.

(Figure 4B). In this case, the position of the tip end surface 9a of the iron core 9 coincides with the bottom surface 9'a, and is maintained at a predetermined distance G2 from the stepped portion 8'a corresponding to the support surface of the diaphragm 12.

Next, after molding with synthetic resin injected through the injection port d (Fig. 4C), the male mold A and the female mold B are separated from each other,
A molded product is obtained in which the iron core 9 is integrally molded to the bottom 8b of the storage case 8 (FIG. 4D).

According to the mold bottom shape described above, the tip end surface 9a of the iron core 9 with respect to the stepped portion 8a of the storage case 8, which serves as the support surface of the diaphragm 12.
Since the position of G2 can be set within the error range determined by the mold, the gap G2 can be managed with high precision.

Further, since a part of the protrusion 9b protruding from the iron core 9 is provided with a crushing margin, the machining error of the iron core 9 can be absorbed by this crushing margin.

Therefore, the processing accuracy of the iron core 9 may be relatively rough, and the processing cost of the iron core 9 can be reduced.

As described above, the present invention has an electromagnet, a diaphragm that faces the end face of an iron core constituting the electromagnet via a gap, and a support surface that supports the diaphragm, and is formed into a bottomed cylindrical shape. an iron core integrally erected on the bottom of the storage case, a washer made of a magnetic material and placed on the inner surface of the bottom of the storage case through the iron core; Since it is characterized by having a permanent magnet arranged on the washer so as to surround the electromagnet, the following effects can be obtained.

(a) It is possible to provide a high-quality buzzer with very high gap accuracy between the diaphragm and the tip end face of the iron core.

(b) It is possible to provide an inexpensive buzzer with low variation in gap accuracy, constant high quality, and excellent mass productivity.

(C) It is possible to provide an inexpensive buzzer that is easy to handle and does not require a gap adjustment mechanism.

(d) A small and lightweight buzzer can be provided.

(e) As shown in the embodiment, the machining errors and forming errors of the iron core 9 can be absorbed by the crushing margin provided on the iron core 9, making it easier to process the iron core 9 and significantly reducing its cost.

(f) By employing a rubber magnet, a resin magnet, or the like as the permanent magnet 11, rattling noise can be prevented and sound quality can be improved.

[Brief explanation of drawings]

Figure 1 is a sectional view of a conventional buzzer, Figure 2 is a sectional view of a buzzer according to the present invention, Figure 3 is an exploded perspective view thereof, and Figure 4A.
-D is a diagram showing a mold forming process. 8...Storage case, 9...Iron core, 10...Coil, 11
...Permanent magnet, 12...Vibration plate.

Claims (1)

[Scope of utility model registration request] An electromagnet, a diaphragm facing an end face of an iron core constituting the electromagnet via a gap, and a storage case formed into a cylinder with a bottom and having a support surface for supporting the diaphragm; an iron core whose lower end is integrally buried and erected in the bottom by molding; a washer made of a magnetic material that is passed through the iron core and placed on the inner surface of the bottom of the storage case; and the washer. and a permanent magnet placed above the electromagnet so as to surround the electromagnet.