JP3320948B2 - Electromagnetic acoustic transducer and winding method of its winding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic acoustic converter for converting an electric signal inputted by electromagnetic conversion into sound and a method for winding its winding.

[0002]

2. Description of the Related Art FIG. 6 shows a general internal structure of a conventional electromagnetic acoustic transducer. This electromagnetic acoustic transducer includes a case 102, a yoke 104, a pole 106, a winding 108,
A magnet 110 and a diaphragm 112 are provided. A magnetic piece 114 is attached to the center of the upper surface of the diaphragm 112 as a means for enhancing the substantial vibration mass of the diaphragm 112, and a resonance chamber 116 is provided on the upper surface thereof by the case 102.
Are formed. The case 102 includes the resonance chamber 11
A sound emission tube 118 is formed as means for emitting the resonance sound generated in 6 to the outside. The sound emission tube 118 is formed with a sound emission hole 120 for opening the resonance chamber 116 to the outside air.

In this electromagnetic acoustic transducer, a yoke 104 is installed on the back side of a case 102, and a base end 107 of a pole 106 forming a magnetic core is attached to the center of the yoke 104 by means such as press fitting. A winding 108 is wound around the pole 106. A cylindrical magnet 110 is installed around the winding 108, and a diaphragm 112 is installed on the upper surface of the magnet 110. The diaphragm 112 is formed of a magnetic material plate, and is held by the magnetic force of the magnet 110. A gap 122 is formed between the lower surface of the diaphragm 112 and the end surface of the pole 106 so as to form an allowable space for mechanical vibration of the diaphragm 112.

In such an electromagnetic acoustic transducer, a magnet 110, a yoke 104, a pole 106, a gap 12
2. A closed magnetic circuit is formed by the diaphragm 112 and the magnetic piece 114, and a bias magnetic field is applied to the diaphragm 112 by the magnetic force of the magnet 110. A terminal (not shown) is formed on the winding 108, and an electric signal to be converted into sound is applied from the terminal. When the winding 108 is excited by this electric signal, the pole 10
6 generates an alternating magnetic field, which causes the diaphragm 112 to vibrate. As a result, resonance vibration occurs in the resonance chamber 116, and the sound is emitted to the outside from the sound emission hole 120. It is known that the level and frequency of the sound depend not only on the input signal but also greatly affect the acoustic characteristics of the electromagnetic acoustic transducer.

[0005]

As is well known, the magnetic field generated at the pole 106 depends on the number of turns of the winding 108. In order to increase the generated magnetic field, it is necessary to increase the number of turns of the winding 108. However, there is a demand for downsizing of the electromagnetic acoustic transducer, and the increase in the number of turns of the winding 108 is naturally limited. is there.

Conventionally, in the electromagnetic acoustic transducer, as shown in FIG. 6, the winding 108 has a flattened winding wall 124 on the tip side of the pole 106. Such flattening has been performed when the pole 106 is wound directly or when a bobbin is used, and such a form is generally used.

On the other hand, Japanese Unexamined Utility Model Publication No. 2-120998 “Electro-acoustic transducer” has a conical surface so that a winding is wound around the tip end surface of a pole and the wound wall surface is retracted to the outer peripheral surface side. It was made. When the winding wall surface is formed on such a conical surface, the vibration amplitude of the diaphragm becomes smaller as it goes to the surroundings, so that the effective space of the winding becomes a problem.

By the way, there is a demand for automation of the production of the electromagnetic acoustic transducer. In conventional electromagnetic acoustic transducers, it has been mainstream that individual parts are machined and assembled by hand. Due to a demand for reduction in manufacturing cost, there has been an attempt to make the process of forming individual parts continuous and to automate the assembly thereof.

In addition to the demand for miniaturization of the electromagnetic acoustic transducer, it is necessary to meet the conflicting demand not to reduce the vibration characteristics and the magnetic force generated by the winding.

Accordingly, a first object of the present invention is to provide an electromagnetic acoustic transducer capable of increasing the number of turns of a winding and contributing to automation of the winding.

It is a second object of the present invention to provide a method of winding a winding of an electromagnetic acoustic transducer which automates the formation of the winding.

[0012]

In order to achieve the first object, a pole (6) attached to a yoke (4) as shown in FIGS. 1 to 5 is provided. An electroacoustic transducer in which a winding (10) is wound around the pole and a tip of the pole faces a diaphragm (18),
Wherein the winding to expose the peripheral surface of the tip end of the pole is wound up winding width of the winding (13) is set equal to the length of the pole, the cutout portion of the yoke ( 38)
The wire material at the winding start end side and the winding end side of the winding
(48) is connected to a lead terminal (34,
36), and wrap the wire around the lead terminal.
Characterized in that that.

Further, in the electromagnetic acoustic transducer of the present invention,
The wall surface (14b) formed by the maximum winding width portion of the winding is:
It is characterized by being set parallel to the diaphragm.

[0014]

In order to achieve the second object, the method of winding a winding of an electromagnetic acoustic transducer according to the present invention, as illustrated in FIG. 4, is a pole (6) attached to a yoke (4).
A method of winding a winding of an electromagnetic acoustic transducer in which a winding (10) is wound around a pole and a tip end face of the pole faces a diaphragm, wherein the tip of the pole is held by a rotatable chuck. In addition, by forming the yoke as a free end and rotating the pole together with the chuck, a wire rod (48) is wound around the peripheral surface of the pole, and the winding is wound and formed on the chuck. Face (4
According to 4), by forming an end face of the winding formed by laminating the wires, a minimum winding width portion that exposes a peripheral surface portion on a tip end side of the pole is formed, and an outer periphery of the winding is formed. A maximum winding width portion is formed in the direction.

In the method for winding a winding of an electromagnetic acoustic transducer according to the present invention, the winding start end (48S) and the winding end (48E) of the wire are connected to lead terminals projecting from the yoke. It is characterized by being hung and held.

[0017]

In the electromagnetic acoustic transducer of the present invention, the winding is wound so as to expose the peripheral surface on the tip side of the pole. The maximum winding width of the winding is set to be equal to the effective length of the pole around which the winding is wound, that is, the length of the pole projecting from the yoke. With this configuration,
Even if the pole length is shortened, it is possible to generate a magnetic field equivalent to a case where a winding is wound around the entire effective length, and as a result, it contributes to downsizing of the electromagnetic acoustic transducer. In particular, the vibration of the diaphragm has a tendency to decrease as its center reaches the periphery at the maximum, but the form of the winding of the present invention corresponds to such a vibration mode of the diaphragm, The winding space of the winding can be enlarged, and the magnetic force can be generated efficiently. Also, the yoke has a pole on one side,
Lead terminals protrude from the other surface and
Since a cut-out part is formed on the back side,
Is the winding start end of the winding wound on the pole and the winding
Pass the wire at the end through the notch,
Wrapped around. In this way, wire the notch of the yoke
By passing between the front and back of the yoke through the part,
The wire is not routed around the outer surface of the yoke,
The fixing structure can be simplified, and the reliability of wire connection
Enhanced.

Further, when the wall surface formed by the maximum winding width portion of the winding is set to be parallel to the diaphragm, the vibrating state of the diaphragm does not come into contact with the winding. The number of turns can be secured.

[0019]

In the method of winding the winding of the electromagnetic acoustic transducer of the present invention, the tip of the pole is held by a rotatable chuck, and the pole is rotated together with the chuck with the yoke side as a free end. Wrap the wire around the pole. Then, the wound end surface formed by laminating the wire rods is formed by the forming surface formed on the chuck. As a result, the desired winding is wound within the space between the chuck and the yoke, and the winding wall surface on the chuck side is formed by the forming surface formed on the chuck. By partially retreating to the tip end side, it is possible to form a wound wall surface equivalent to the pole end face described above, and as a result, to expose the peripheral surface portion on the tip end side of the pole to the minimum winding In addition to setting the width, a maximum winding width equivalent to the pole length can be set.

In the method of winding a winding of an electromagnetic acoustic transducer according to the present invention, a winding start end and a winding end of a wire forming the winding are pulled out from a notch of the yoke and wound around a lead terminal. As a result, the shape of the winding in the course of winding can be maintained, and unwinding and loosening can be prevented.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments shown in the drawings.

FIG. 1 shows an embodiment of the electromagnetic acoustic transducer of the present invention, and FIG. 2 shows a pole piece portion of the electromagnetic acoustic transducer.

The pole piece 2 of this electromagnetic acoustic transducer
Is composed of a disk-shaped yoke 4 and a pole 6, and the pole 6 has a smaller diameter at the base end 8 side, and
Is attached to the center of the yoke 4 by fixing means such as press fitting.

A winding 10 is wound around the pole 6, and its peripheral surface forms a concentric cylinder with the pole 6. In this embodiment, the winding 10 is formed such that the base end 8 of the pole 6 is applied to the yoke 4 to form a uniform winding surface. Is formed in the diameter direction of the winding 10, a maximum winding width portion 13 is formed from an intermediate portion to the outermost peripheral side, and winding wall surfaces 14 having different heights are formed in the diameter direction of the winding 10. The height D <b> 13 of the maximum winding width portion 13 of the winding 10 is set in a range from the upper surface of the yoke 4 to the protrusion length of the pole 6, which is equivalent to the range in which the winding 10 can be wound. The height D11 of the minimum winding width portion 11 of the winding 10 is set in a range from the upper surface of the yoke 4 to the exposed portion of the peripheral surface of the tip of the pole 6. That is, the winding wall surface 14 is formed by the first and second wall surfaces 14a and 14b having different shapes. That is, the first
The wall surface 14a has a funnel-shaped surface for exposing a part of the distal end of the pole 6, and the second wall surface 14b has a flat surface so as to form the same plane as or near the distal end surface of the pole 6. It has been. As a result, as shown by the broken line in FIG. 2, it is the conventional winding 108 is effective number of turns of the axial height D ₀ only winding 10 of the pole 6 as compared with the (FIG. 6) has increased . Assuming that the conventional winding 108 and the winding 10 have the same outer diameter and wire, the magnetic field generated by the height D ₀ is correspondingly increased. In other words,
When the maximum winding width portion 13 of the winding 10 is set to the same height as the winding wall surface of the conventional winding 108, the generated magnetic field is increased by the amount of the exposed peripheral surface of the pole 6 on the tip end surface 12 side. However, the decrease in the generated magnetic field can be easily compensated for by increasing the number of turns of the winding 10 in the diameter direction.

The electromagnetic acoustic transducer has the same configuration as the conventional electromagnetic acoustic transducer (FIG. 6). A magnet 16 having an annular shape centering on the pole 6 is provided above the pole piece 2. Installed and fixed. A diaphragm 18 is provided on the magnet 16, and a magnetic piece 20 is attached to the center of the diaphragm 18 as a means for increasing the substantial vibration mass of the diaphragm 18. In this embodiment, the height of the magnet 16 is set higher than the height of the pole 6 so that
A gap 22 is formed as a means for forming a space in which the vibration of the diaphragm 18 is shared between the first and second diaphragms. Further, the vibration plate 18 and the magnetic piece 20 are formed of a magnetic material. The vibration plate 18 is fixed on the magnet 16 by the magnetic force of the magnet 16, and is used for generating a magnetic field vibration. A bias magnetic field is applied by a magnet 16 as an element. As in the conventional electromagnetic acoustic transducer, the pole piece 2, the magnet 16, the gap 22, the diaphragm 18 and the magnetic piece 20 form a single closed magnetic path. In addition, a magnetic drive unit that converts an external electric signal into a magnetic field and acts on the diaphragm 18 is configured.

A case 24 is placed on the peripheral surface of the pole piece 2 and the upper surface of the diaphragm 18. The case 24 is a molded body made of a nonmagnetic material such as a synthetic resin, and has a resonance chamber 26 formed on the upper surface side of the diaphragm 18. Further, a resonance cylinder 28 is formed in the case 24, and the resonance chamber 26 is opened to the outside air in the resonance cylinder 28,
A sound emission hole 30 is formed as a means for emitting a resonance sound. In the case of this embodiment, the resonance cylinder 28 and the sound emission hole 30 are formed at the center of the diaphragm 18, but may be formed at positions other than the center of the diaphragm 18.

According to such an electromagnetic acoustic transducer, when an electric signal is externally applied to the terminal connected to the winding 10, the winding 10 is excited according to the level. As a result, an alternating magnetic field is generated at the pole 6,
This alternating magnetic field acts on the diaphragm 18 and the magnetic piece 20. Since a bias magnetic field is applied to the diaphragm 18 by the magnet 16, the diaphragm 18 receives a vertical vibration force according to the frequency of the alternating magnetic field superimposed on the bias magnetic field and the level thereof. As a result, the diaphragm 18 vibrates,
The vibration vibrates the air on the upper and lower sides of the diaphragm 18, and a resonance sound is generated in the resonance chamber 26. The vibration sound of the diaphragm 18 and the resonance sound of the resonance chamber 26 are emitted to the outside through the sound emission holes 30. The frequencies of such resonances are distributed in the voice band, which is why the electromagnetic acoustic transducer is used as a sounding means such as a buzzer.

In this electromagnetic acoustic transducer, the winding 1
The number of turns of ₀ is larger than that of the winding 108 of the conventional electromagnetic acoustic transducer by the height D ₀ , and as a result, the generated magnetic field is larger. This means that, for the same input, the magnetic force for exciting the diaphragm 18 increases. Therefore, the sound pressure of the electromagnetic acoustic transducer is enhanced.

Further, such an increase in the generated magnetic field causes a change in the input and the electromagnetic acoustic transducer on the basis of the same magnetic field generation as in the related art. That is, when generating a magnetic field similar to that of the conventional electromagnetic acoustic transducer (FIG. 6),
The input power to be applied to the winding 10 can be suppressed. In addition, when the same input and the same generated magnetic field are assumed, the height of the pole 6 can be shortened accordingly. This reduction in height corresponds to the number of turns of the winding 10 having a height D ₀ , and as a result, the height of the electromagnetic acoustic transducer can be reduced,
The outer shape can be reduced.

The winding 10 at the height D ₀ effectively utilizes the space behind the diaphragm 18 and does not hinder the vibration of the diaphragm 18 at all. This is because the vibration of the vibration plate 18 has a maximum vibration at its center and decreases toward its periphery. Therefore, increasing the winding 10 by the height D ₀ means that the driving force of the diaphragm 18 is increased while causing the diaphragm 18 to generate the same vibration as in the related art.

The first and second wall surfaces 14 of the winding 10
a and 14b are formed by the minimum winding width portion 11 and the width in the thickness direction of the maximum winding width portion 13, but the width of the maximum winding width portion 13 in the thickness direction can be arbitrarily set, The inclination angle between the first winding wall surface 14a and the outer peripheral surface of the pole 6 can be arbitrarily changed depending on the width of the maximum winding width portion 13 in the thickness direction.

In the electromagnetic acoustic transducer shown in FIGS. 1 and 2, the second wall surface 14 b of the winding 10 is made to coincide with the tip surface 12 of the pole 6. It may be set so as to protrude toward the diaphragm 18 from the distal end surface 12 or to retract from the distal end surface 12 of the pole 6.

Although the description of the lead terminal is omitted in this embodiment, the terminal may be formed at the end of the winding 10 or the insulating material may be interposed on the back side of the yoke 4. Lead terminals may be formed.

Next, FIG. 3 shows a specific configuration example of a pole piece portion used in the electromagnetic acoustic transducer of the present invention.

The pole piece portion 6 is formed by mounting a substrate 32 on the upper surface of the yoke 4 to form a laminated plate, passing the base end portion 8 of the pole 6 through the laminated plate, and caulking the end portion. The yoke 4 is provided with a pole 6 protruding therefrom.
On the side, lead terminals 34 and 36 are projected from the pole 6 in the middle. The yoke 4 is formed of a magnetic material in a disk shape, and the substrate 32 is provided with lead terminals 34 and 36 of the yoke 4.
Are formed in a constant width in the interval direction. In the yoke 4 and the substrate 32, U-shaped notches 38, 4, which penetrate through the front and back surfaces of the yoke 4, are provided in the space between the lead terminals 34, 36.
0 is formed.

Next, FIGS. 4 and 5 show an embodiment of a method of winding a coil around the pole piece 2 shown in FIG.

In this winding method, a chuck device 42 is used as a holding means and a rotating means for the pole piece 2. A rotation drive unit such as a motor is connected to the chuck device 42 via a rotation transmission mechanism (not shown), and the rotation drive unit performs rotation control such as a rotation speed and a rotation speed by a control unit (not shown). The claw portion 43 of the chuck device 42 is divided into a plurality of portions, and the tip of the pole 6 of the pole piece portion 2 is gripped by the claw portion 43 and the yoke 4
The side is set at the free end. The gripping of the pole piece 2 by the claw 43 is performed by mechanical force such as air pressure, hydraulic pressure, and electromagnetic force.

On the front side of the claw portion 43, the winding wall surface 1 of the winding 10 wound around the pole 6 of the pole piece portion 2 is provided.
4 is formed. The molding surface 44 has a first molding surface 44a formed of a conical surface for forming the first wall surface 14a, and a second molding surface 44b for forming the second wall surface 14b.

Therefore, when winding the winding 10, the tip of the pole 6 of the pole piece 2 is gripped by the claw 43 of the chuck device 42. Since this gripping position determines the winding width of the winding 10, that is, the exposed portion of the pole 6, it is necessary to accurately position the pole. In this case, the chuck device 4
2 includes a pin 4 as positioning means inside the claw portion 43.
5 is built in, and this pin 45 is moved forward and backward by driving means such as a cylinder. By moving the position of the tip of the gripping dimension of the pin 45, the gripping dimension of the pole 6 of the pole piece 2 gripped by the claw 43 is determined. As a result, the molding surface 44 and the wall surface of the yoke 4 of the pole piece 2 are determined. A space 46 surrounded by is formed. This space 46 forms an effective winding space of the winding 10.

Then, after the winding start end 48S of the wire 48 is locked to the locking portion 50, the wire 48 is wound near the distal end of the terminal 36, and the locking portion 50 is moved to move the wire 48. Disconnect. Next, the wire 48 wound around the lead terminal 36 is connected to the lead terminal 34 and the yoke 4 of the lead terminal 36.
Is guided from the notch portion 38 to the pole 6 side through the vicinity of the mounting portion, and the chuck device 42 is rotated, for example, in the direction indicated by the arrow N, so that the wire rod 48
Wrapped around. As a result, the winding 10 is formed inside the space 46, and the end of the winding 10 is led from the notch 38 to the lead terminal 34 side, and wound around the leading end of the lead terminal 36 via the lead terminal 34, The winding process is completed by moving the locking portion 50 and cutting the wire rod 48.
In this case, FIG. 4 shows the introduction and withdrawal of the wire 48 between the pole 6 side and the lead terminals 34 and 36 through the notch 38 of the pole piece 2, and the arrow attached to the wire 48. Indicates the direction.

Then, the wire 10 is moved from the surface of the pole 6 to the molding surface 4 of the claw 43 of the chuck device 42 by rotating the chuck device 42 in the direction of arrow N.
4A and 44B, the peripheral surface on the tip surface 12 side of the pole 6 is exposed, and the maximum winding width portion 13 equivalent to the height of the pole 6 is fixed as shown in FIG. The winding 10 is formed so as to be ready for the width and to expose the peripheral surface on the tip end side of the pole 6.

When the chuck device 42 is used as described above, the winding 6 shown in FIG. 2 can be wound by gripping the pole 6 of the pole piece 2, and the yoke 4 side is a free end. Therefore, the holding means on the yoke 4 side becomes unnecessary,
With the simplification of the device, the holding operation becomes unnecessary, and the winding 1
0 can be simplified. In particular, when the yoke 4 side is a free end, there is an advantage that even if the lead terminals 34 and 36 are provided, it is not necessary to release them on the holding member side.

Also in this embodiment, the surface of the claw portion 43 may be Teflon-coated or mirror-finished in order to make the surface of the claw portion 43 well separated from the wall surfaces 14a and 14b of the wound winding 10.

Further, since the claw portion 43 of the chuck device 42 is divided into a plurality of portions, such as three, the tip of the pole 6 of the pole piece portion 2 can be gripped and released by opening and closing. When the winding of the winding 10 is completed, the pawl portion 43 is opened, and the pole piece portion 2 can be dropped by its own weight. However, if it is difficult to drop the pole piece portion 2, means such as air blowing may be used together.

When the pole piece 2 is not detached from the chuck device 42, the pole piece 2 can be reliably detached from the chuck device 42 by moving the pin 45 upward in the drawing.

Although the present invention has been described in terms of the features with reference to the embodiments, the present invention includes various modifications without departing from the purpose thereof.

[0048]

As described above, according to the present invention,
The following effects can be obtained. a. As described above, according to the electromagnetic acoustic transducer of the present invention, the winding efficiency of the winding of the pole piece portion with respect to the pole is increased, and there is no need to secure a special winding space for the winding. The space created can be effectively used for winding the winding, and an electromagnetic acoustic transducer with high sound pressure can be obtained, and the electromagnetic acoustic transducer can be reduced in size and flattened. Can also be automated. b. In addition, according to the method of winding the winding of the electromagnetic acoustic transducer of the present invention, the winding efficiency of the winding around the pole of the pole piece portion can be increased, and the speed of the winding process can be increased, thereby increasing the productivity. The winding efficiency can be increased by devising the shape of the winding.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of an electromagnetic acoustic transducer of the present invention.

FIG. 2 is a sectional view showing a pole piece used in the electromagnetic acoustic transducer shown in FIG.

FIG. 3 is a perspective view showing a specific configuration example of a pole piece portion of the electromagnetic acoustic transducer.

FIG. 4 is a diagram showing a winding method of a winding of the electromagnetic acoustic transducer of the present invention.

FIG. 5 is a plan view showing terminal processing of a winding.

FIG. 6 is a longitudinal sectional view showing a conventional electromagnetic acoustic transducer.

[Explanation of symbols]

 Reference Signs List 4 yoke 6 pole 10 winding 11 minimum winding width portion 13 maximum winding width portion 14 winding wall surface 14a first wall surface 14b second wall surface 18 diaphragm 38 notch portion 44 forming surface 48 wire rod 48S winding start end 48E winding end

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04R 13/00 G10K 9/13 101

Claims (4)

(57) [Claims] 1. An electromagnetic acoustic transducer in which a winding is wound around a pole attached to a yoke, and a tip of the pole is opposed to a diaphragm, wherein a peripheral surface on a tip side of the pole is exposed. the winding is wound, the maximum winding width of the coil is set to equal to the length of the pole, the winding through notch of the yoke
The wires at the winding start end and the winding end are protruded from the yoke.
To the installed lead terminal, and the wire
An electromagnetic acoustic transducer characterized by being wound . 2. The electromagnetic acoustic transducer according to claim 1, wherein a wall surface defined by the maximum winding width portion of the winding is set in a state parallel to the diaphragm. 3. A method for winding a winding of an electromagnetic acoustic transducer in which a winding is wound around a pole attached to a yoke, and a tip end surface of the pole is opposed to a diaphragm. While holding the tip of the pole, making the yoke a free end, and rotating the pole together with the chuck, a wire is wound around the peripheral surface of the pole, and the winding is wound around the chuck. According to the formed forming surface, by forming the end face of the winding formed by laminating the wire material, while forming a minimum winding width portion that exposes the peripheral surface portion on the tip side of the pole, A method for winding a winding of an electromagnetic acoustic transducer, wherein a maximum winding width portion is formed in an outer circumferential direction of the winding. 4. The electromagnetic acoustic transducer according to claim 3 , wherein a winding start end and a winding end of the wire are wound around and held by lead terminals protruding from the yoke. Winding method of winding.