JP2004253901A - Electromagnetic horn and manufacturing method of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive electromagnetic horn for eliminating the need for the screw part of a core mount for the purpose of air-gap adjustment, the components of which can easily be worked and for eliminating the need for special waterproof countermeasures, and to provide a manufacturing method of the electromagnetic horn whose air-gap can easily be adjusted. <P>SOLUTION: The electromagnetic horn is configured such that a projection is provided at the eccentric position of one side of an armature opposed to a core, a slope is provided to the side of the core, and an air-gap between the projection and the slope is changed when the armature is rotated with respect to the core. An adjustment tool is used to press the armature toward the core, the air-gap is measured on the basis of the movement amount of the armature when the armature is pressed into contact with the core and the air-gap is adjusted. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electromagnetic horn used in automobiles and the like, and more particularly to a configuration of an electromagnetic horn in which an air gap between a fixed core and a movable armature can be easily adjusted, and a method of manufacturing the electromagnetic horn.
[0002]
[Prior art]
As a general configuration of an electromagnetic horn used for an automobile or the like, for example, a configuration described in Patent Literature 1 is known.
As shown in FIG. 5, the electromagnetic horn described in Patent Document 1 has a substantially bowl-shaped housing 1, and an electromagnetic coil 2 in which an electric wire is wound around a hollow coil bobbin 2 a is disposed at the bottom of the housing 1. Is established. The core 3 provided with the male screw 3a is adjustably fixed to the female screw cylinder 1a formed on the bottom surface of the housing 1, and the main body of the core 3 is disposed in the hollow portion of the coil bobbin 2a. A thin plate-shaped diaphragm 5 having an armature 4 attached at the center is disposed in the front opening of the housing 1, and a circumferential portion of the diaphragm 5 is fixed by caulking to a peripheral edge of the opening of the housing 1. . The lower surface of the main body 4a of the armature 4 faces the upper surface of the core 3 with a slight gap G (air gap). Reference numeral 6 denotes a disk-shaped resonance plate arranged on the upper surface of the vibration plate 5. The resonance plate 6 is attached to the extension 4 b of the armature 4 at an appropriate distance from the vibration plate 5.
[0003]
In the electromagnetic horn configured as described above, when an intermittent current is supplied to the electromagnetic coil 2 via a current interrupter (omitted in FIG. 5), the armature 4 is generated by the magnetic force generated in the electromagnetic coil 2. It is sucked intermittently in the direction of the core 3. Then, the armature 4 and the core 3 repeatedly collide with and separate from each other due to the elastic force of the diaphragm 5 and the magnetic force. By this operation, the diaphragm 5 vibrates and the resonance plate resonates, so that an alarm sound is generated. ing.
Note that a small gap G (air gap) between the core 3 and the armature 4 is extremely important for stably generating an alarm sound by the above operation. For this reason, in the electromagnetic horn having the above-described structure, the gap G ( The air gap is adjusted.
[0004]
[Patent Document 1] Japanese Patent No. 3205256 FIG. 4 [0005]
[Problems to be solved by the invention]
In the conventional electromagnetic horn described in Patent Literature 1, although the gap G (air gap) can be easily adjusted by using the screwing structure of the core 3 after assembly, the male thread 3a is attached to the core 3 and the bottom surface of the housing 1 is provided. It is necessary to provide the female threaded tube portion 1a in the above, and there has been a problem that the processing of the parts is troublesome and expensive. In addition, rainwater easily penetrates along the threaded connection between the male screw 3a of the core 3 and the female screw cylinder 1a of the housing 1, and it is necessary to apply a waterproof resin or the like.
Further, adjustment of the gap G (air gap) in the electromagnetic horn having the above configuration is performed by manually rotating the core 3 while the electromagnetic horn is operated, and it is difficult to automate the operation and many man-hours are required for adjustment. There is a problem that it takes.
[0006]
The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide an inexpensive electromagnetic horn which can easily process parts and does not require special waterproofing measures, and has an air gap. It is an object of the present invention to provide a method for manufacturing an electromagnetic horn in which the adjustment of the horn is easy.
[0007]
Means for Solving the Problems, and Functions and Effects of the Invention
In order to solve the above problems, the invention of claim 1 includes a housing in which an electromagnetic coil and a core are disposed, and an armature in which a diaphragm and a resonance plate are attached to an opening of the housing. An air gap is provided between the core and the armature. When an intermittent current is supplied to the electromagnetic coil, the core and the armature repeatedly collide (suck) and separate from each other to generate an alarm sound. A projection is provided at an eccentric position on one side facing the armature and an inclined surface is provided on the other side, and the air gap between the core and the armature changes due to the axial rotation of the armature. It is characterized by having such a configuration.
For this reason, there is no need for a threaded portion for attaching the core as in the prior art, the processing of parts is simple, and no special measures are required to prevent rainwater from entering from the threaded portion.
The invention according to claim 2 is characterized in that the protrusion is formed in a substantially conical shape, and the shape and working of the part are easy and practical.
[0008]
According to a third aspect of the present invention, a diaphragm on which an armature and a resonance plate are mounted is placed in an opening of a housing in which an electromagnetic coil and a core are disposed, and the armature is pressed toward the core by an adjusting tool. In the method of manufacturing an electromagnetic horn for measuring the air gap from the amount of movement of the armature at the time of contact, a protrusion is provided at an eccentric position on one side of the armature facing the core, and a protrusion is provided on the other side. There is an inclined surface,
The air gap between the core and the armature is adjusted by rotating the diaphragm on which the armature and the resonance plate are attached relative to the housing.
[0009]
According to a third aspect of the present invention, the air gap between the core and the armature can be adjusted easily and easily by rotating the diaphragm, on which the armature and the resonance plate are attached, relative to the housing. Productivity can be improved.
[0010]
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In order to make the description easy to understand, the same components as those in the above-described conventional example will be denoted by the same reference numerals.
FIG. 1 is a sectional view showing the entire configuration of the electromagnetic horn according to the present invention. Reference numeral 1 denotes a housing having a substantially bowl-like shape and provided with an opening 10 at an upper portion, and a hole 11 is provided at the bottom of the housing 1. The electromagnetic coil 2 has a configuration in which an electric wire is wound around a coil bobbin 2a having a hollow portion 2b. The electromagnetic coil 2 is disposed at the bottom of the housing 1, and the hollow portion 2b of the coil bobbin 2a is And overlap. Reference numeral 3 denotes a columnar core made of a magnetic material such as iron. The core 3 is disposed in the hollow portion 2b of the coil bobbin 2a, and is fixed to the periphery of the hole 11 of the housing 1 by a caulking portion 3b.
The extending portion 3a of the core 3 projects outside the housing 1 below the hole 1 through the hole 11 of the housing 1, and a plate-shaped holder 20 is attached using a male screw and a nut 21 provided on the extending portion 3a. I have.
[0011]
Reference numeral 4 denotes an armature including a cylindrical main body 4a made of a magnetic material such as iron and an extended portion 4b protruding upward. The main body 4a has a diameter substantially equal to that of the core 3, and The lower surface of the main body 4a is disposed so as to face the upper surface of the core 3 with an air gap G (at an appropriate interval).
The air gap G varies depending on design conditions of a vibration system including a diaphragm 5 and the like, which will be described later. It is a suitable value. In order to generate a warning sound stably, the air gap G is generally adjusted within a range of about 0.1 mm.
[0012]
Reference numeral 5 denotes a disk-shaped diaphragm formed of a thin plate of iron or the like, and a circumferential portion of the diaphragm 5 is fixed by caulking to a peripheral portion of the opening 10 of the housing 1 using a ring member 22. As shown in an enlarged manner in FIG. 2, a ring-shaped thin plate made of a paper material impregnated with an oily material is provided between the circumferential portion of the diaphragm 5 and the peripheral portion of the opening 10 of the housing 1. Gasket 22a is interposed.
An extension 4b of the armature 4 is inserted through the center of the diaphragm 5, and a plurality of washers 23 are interposed between the diaphragm 24 and a male screw provided on the extension 4b. The resonance plate 6 and the resonance plate 6 are fixed together at an appropriate interval.
Therefore, when an intermittent current is supplied to the electromagnetic coil 2 via a current interrupter (not shown in FIG. 1), the armature 4 is intermittently attracted to the core 3 by the magnetic force generated in the electromagnetic coil 2. Is done. Then, the armature 4 and the core 3 repeatedly collide with and separate from each other due to the elastic force of the diaphragm 5 and the magnetic force. By this operation, the diaphragm 5 vibrates and the resonance plate resonates, so that an alarm sound is generated. ing.
(Known operation)
[0013]
Next, the detailed shapes of the armature 4 and the core 3 and the combination of the facing portions will be described with reference to FIG. FIG. 3 is an explanatory view of the principle in which a part of the shape is exaggerated with enlargement.
The lower surface 40 of the main body 4a of the armature 4 is provided with a conical portion 40a having a vertex P at a position eccentric from the center line X. The conical portion 40a has a height H1 of about 0.1 mm, and is set to protrude slightly downward from the lower surface portion 40. The upper surface 30 of the core 3 has a shape obtained by diagonally cutting a cylinder, and the diagonal height H2 is set to about 0.1 mm.
[0014]
Therefore, when the armature 4 is rotated in the direction of arrow A in FIG. 3, the vertex P of the conical portion 40a changes to the position indicated by P ′. Then, the air gap G between the core 3 and the armature 4 at the beginning is changed to G '. That is, in the electromagnetic horn of the present invention, when the diaphragm 5 is rotated before the diaphragm 5 is fixed by caulking by the ring member 22 (in a temporarily assembled state shown in FIG. 1), the core 3 and the armature 4 The air gap G between them can be easily changed.
[0015]
Subsequently, an example of a specific method of adjusting the air gap G and the principle of the procedure will be described with reference to FIG.
FIG. 4 is a side view of the electromagnetic horn of the present invention shown in FIG. 1 during assembly, in which necessary components such as an electromagnetic coil 2 are incorporated in a housing 1. Further, a diaphragm 5 and a resonance plate 6 are attached to the armature 4 at predetermined positions, and the diaphragm 5 is placed so as to close the opening 10 of the housing 1 with a gasket 22a interposed therebetween. That is, in the state of FIG. 4, the caulking process (final assembly) by the ring member 22 is not performed as compared with the state in which the assembly of FIG. 1 is completed.
Reference numeral 31 denotes a holder for holding the housing 1 at a predetermined position, and reference numeral 32 denotes an adjuster which can press the upper end of the extension 4b of the armature 4 while measuring and adjusting the amount of movement downward. A DC power supply 33 has an anode connected to the diaphragm 5 via a current detector 34, and a cathode connected to the housing 1.
[0016]
Next, the procedure of the adjustment will be described. First, the adjusting tool 32 is moved downward (the direction indicated by the arrow B in FIG. 4) from the state of FIG. 4 described above, and the lower surface of the adjusting tool 32 is brought into contact with the upper end of the extending portion 4b of the armature 4, and Is the reference point. When the adjusting tool 32 is further moved downward from this state, the diaphragm is elastically deformed, and the armature 4 moves downward, and after the movement corresponding to the air gap G at that time, the armature 4 and the core 3 come into contact with each other. Touch Then, a current flows through the path of the diaphragm 5, the armature 4, the core 3, and the housing 1, and the current detector 34 detects the current, that is, the contact between the armature 4 and the core 3.
Here, a gasket 22a made of paper material impregnated with an oily substance is interposed between the diaphragm 5 and the housing 1 so that it functions as an electrical insulator, and the diaphragm 5 and the housing 1 Current does not flow directly to the
In FIG. 4, the drive and control means of the adjusting tool 32 are omitted and the current detector 34 is shown for easy understanding of the principle.・ The adjustment is performed using a computer.
[0017]
In the above operation, the air gap G at that time is easily and easily measured, and if this is different from the target value in design, the armature 4, the vibration plate 5, the resonance plate 6, etc. are integrated into a fixed angle. Just rotate. Then, the air gap G changes according to the rotation angle according to the principle shown in FIG. By repeating the above operation in this state, the air gap G can be easily and easily adjusted to the target value.
Furthermore, by appropriately setting the amount of eccentricity of the conical portion 40a shown in FIG. 3 in advance, the rotation angle required for the adjustment is calculated from the difference between the measured value and the target value, and the adjustment is efficiently performed. Is also possible.
Next, after the above measurement and adjustment are completed, if the diaphragm 5 is swaged and fixed to the peripheral edge of the housing 1 using the ring member 22, the assembly of the electromagnetic horn having the predetermined air gap G is completed.
[0018]
Although the embodiment of the present invention shown in FIGS. 1 to 4 has been described above, for example, when a gasket 22a in which an oily substance is impregnated in paper is not used, an appropriate AC voltage is applied to the electromagnetic coil 2. By applying and detecting a change in the impedance, it is possible to make a change such as detecting the contact between the armature 4 and the core 3.
[0019]
In the above embodiment, the electromagnetic horn in which the armature collides with the core has been described. The present invention is also applicable to a so-called spiral horn having a structure in which resonance is performed by using a spiral duct arranged in a spiral.
【The invention's effect】
According to the present invention, the air gap can be easily and easily adjusted by integrally rotating the armature 4, the diaphragm 5, the resonance plate 6, and the like by a predetermined angle. In addition, it is easy and inexpensive to process and assemble parts, and it is excellent in practicability because it is not necessary to take special waterproofing measures for the threaded joint of the core as in the conventional case.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an overall configuration of an electromagnetic horn according to the present invention.
FIG. 2 is an enlarged cross-sectional view showing a mounting portion between a housing 1 and a diaphragm 5 of the electromagnetic horn shown in FIG.
FIG. 3 is a principle explanatory view showing shapes of a core 3 and an armature 4 of the electromagnetic horn shown in FIG.
FIG. 4 is a side view for explaining the principle of adjustment of the electromagnetic horn of the present invention shown in FIG.
FIG. 5 is a sectional view showing a configuration of a conventional electromagnetic horn.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Housing 2 Electromagnetic coil 2a Coil bobbin 3 Core 30 Upper surface part 4 Armature 40 Lower surface part 40a Conical part 5 Vibration plate 6 Resonance plate 22 Ring member 22a Gasket G Air gap P Apex

Claims (3)

It has a housing in which an electromagnetic coil and a core are disposed, and an armature in which a diaphragm and a resonance plate are attached to the opening of the housing, and an air gap is provided between the core and the armature. When an intermittent current is supplied to the coil, the core and the armature collide with each other (attractive) and separate from each other.
A projection is provided at an eccentric position on one side of the core and the armature facing each other, and an inclined surface is provided on the other side,
An electromagnetic horn, wherein an air gap between a core and an armature is changed by rotation of an armature shaft. The electromagnetic horn according to claim 1, wherein the projection is formed in a substantially conical shape. A diaphragm having an armature and a resonance plate mounted thereon is placed in an opening of a housing in which an electromagnetic coil and a core are disposed, and the armature is pressed in the direction of the core by an adjusting tool to contact the armature. In a method of manufacturing an electromagnetic horn for measuring an air gap from a moving amount of
A projection is provided at an eccentric position on one side of the core and the armature facing each other, and an inclined surface is provided on the other side,
A method of manufacturing an electromagnetic horn, comprising: adjusting an air gap between a core and an armature by rotating a diaphragm on which an armature and a resonance plate are attached relative to a housing.

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