JPS62220100A - Converter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) This invention relates to an airborne acoustic wave driver (transducer). More particularly, the invention relates to a transducer that converts electrical signals into corresponding airborne sound vibrations, such as in a loudspeaker.

BACKGROUND OF THE INVENTION It is well known that switching systems of the type that convert electrical energy into mechanical energy are particularly inefficient in operation. Generally, only a small portion of the total electrical energy supplied to such conversion systems is actually converted into mechanical energy and made available.

It is also well known that even if the electrical energy supplied to the conversion system is in the desired form, the resulting energy signal from the converted circuit will not correspond exactly to the input. It is.

The difference between the content of the output signal results in a distortion, the form of which depends on the configuration of the conversion system. Furthermore, since transducers typically operate as components of larger systems,
The inefficiency of converting one form of energy into another increases the distortion of the system. For example, to convert electrical energy from an amplifier into airborne sound waves S!1!I, i.e. sound pressure waves. The inefficiency of the acoustic loudspeaker in converting mechanical energy into mechanical energy requires the amplifier to supply a very large amount of electrical energy to obtain a receivable sound pressure level. The strain caused will be J ['7].

As is well known, a transducer used as a loudspeaker generally includes a drive device for receiving an electrical signal, and a drive device for receiving an electrical signal. It has a diaphragm that is connected to the ll device and vibrates in accordance with the received signal.

For example, a drive device such as a voice coil usually has a coil and a V11 core inside the coil, and a magnetic
The a moves in response to the magnetic field generated by the excitation of the coil. In these cases, the coil is fixed to the diaphragm, for example at its center point, while the diaphragm is attached at its outer periphery by a hinge or the like. It is known that in other cases the diaphragm is driven by a circumferential force. One such system is described in US Pat. No. 3,979,506.

However, in this system, the diaphragm is driven unbalanced, resulting in considerable distortion.

Other similar systems include U.S. Pat. No. 3.012.107, U.S. Pat.
listed in the number. It must be kept in mind that any mechanical improvement of the conversion system will only affect the available mechanical energy in a particular way. In other words, in a transducer system that generates axial mechanical reciprocating motion in response to an electrical input, various mechanical modifications only change short, strong vibrations to long, weak vibrations, or vice versa. Guaru.

Therefore, the amount of work defined as the product of the mechanical force and the distance over which the force is applied remains virtually the same, and no fundamental improvement in conversion efficiency is achieved. In many loudspeaker configurations, the focus is generally on the diaphragm, which is the element that couples directly to the air.
The primary concern is its quality. Although developing efficient, low-quality, and small diaphragms is a worthy design goal, advances in materials science and manufacturing methods are
It has become possible to manufacture a lighter diaphragm that is smaller than IJJ devices. As is well known, efficiency is related to the ratio of voice coil to diaphragm ml.
To maintain efficient operation, reducing the mass of the diaphragm requires a corresponding reduction in the weight of the drive coil. This makes the J3
This is important because it reduces the mechanical advantage of coupling with low frequency signals that load the center of the diaphragm.

From this examination, it becomes clear that the peripheral drive provides an improved mechanical advantage for the operation of the electromagnetic transducer system at high frequencies, whereas at low frequencies this improvement is not an advantage. This is because low frequencies generate the maximum sound pressure near the center of the diaphragm, which is the area farthest from the peripheral drive bag type. The sound waves are radiated along the diaphragm of the transducer, and by producing a light and heavy circumferential drive system in this way, the operating efficiency of the electromagnetic transducer system in high acoustic frequency bands can be improved. Moreover, by reducing the mass of the drive in this way, the efficiency of the conversion system in low frequency bands can also be improved. This is because the instantaneous low-frequency sound pressure wave is originally generated by the diaphragm pushing air in the axial direction with the full width of the diaphragm. At one end of the radial moment arm the drive coil is loaded, while at the other end the load is air.

(Objective) Therefore, it is an object of the present invention to provide an electromechanical conversion system with high energy conversion efficiency.

It is another object of the invention to provide an electromechanical conversion system that maintains a high degree of correspondence between the respective contents of the output signals.

It is a further object of the present invention to provide a simple conversion system using Iff that can be used to create WIJ images on cheap drawings.

It is yet another object of the invention to eliminate distortion in the transducer.

It is yet another object of this invention to eliminate distortion in loudspeakers.

It is yet another object of the invention to provide equivalent but separate electromagnetic circuits for each direction of alternating current.

(Summary of the Invention) In short, this invention, like a loudspeaker,
a sleeve, a diaphragm fixed internally to the sleeve on a central plane, and arranged in mirror symmetry with respect to the sleeve, the sleeve and diaphragm being arranged linearly so as to produce a distortion-free and balanced sound. Provide a transducer consisting of a vibration generator 2ii (4) and a device.

A device for vibrating the sleeve and diaphragm includes a pair of coils wound around the sleeve symmetrically with respect to a central plane, and a device forming a pair of magnetostatic circuits arranged symmetrically with respect to said central plane. . Each coil is
They are equally wound so that equal and similarly oriented electromagnetic forces corresponding to the alternating current supplied to them are generated therein, while each magnetic circuit is provided for each coil.

The inventive arrangement of the coil to magnetic circuit on the sleeve and diaphragm has a low mass and is highly effective for acoustic transducers in the low and high frequency ranges by providing a circumferential drive system that converts mechanical energy more efficiently than conventional systems. Improve behavior.

By winding the coils symmetrically, in particular in mirror image relation to each other, equal magnetic equilibrium is achieved on the diaphragm plane. Each magnetic circuit is of a type that generates radial magnetic field lines. These magnetic field lines then cross the air gap in which the part of the sleeve around which the respective associated coil is wound is located. Excitation of the coil by applying an electrical signal to the end of the coil results in a corresponding mechanical movement of the sleeve in a direction parallel to the solid axis of the magnetic circuit.

In this configuration, the transducer, i.e. the loudspeaker
can produce a distortion-free sound. This is because the electromagnetic force is applied to the sleeve symmetrically, that is, in a well-balanced manner. In this manner, the diaphragm can be imaged in a balanced manner to generate sound waves that faithfully correspond to the received electrical signals.

Furthermore, according to this configuration, in the known conversion system, the sum t1 of the masses required for two symmetric coils to obtain the same conversion efficiency can be smaller than the mass of a single coil. Conversion efficiency is thus improved compared to conventional systems using -b single coils of equal mass.

Note that by further reducing the effective equivalent mass of the circumferential drive system, the mechanical resonant frequency of the sleeve is increased. As a result, the sleeve can generate higher frequency No. 15 through the diaphragm surface. In addition, reducing the sleeve quality h) reduces the effective moment arm at low frequencies for a given conversion efficiency.
This improves efficiency and mechanical advantages during low frequency operation.

These objects and other objects and advantages of the present invention will become more apparent from the following description of embodiments and drawings.

(Embodiment) As shown in FIG. 1, the transducer 10 generally has a cylindrical shape with an opening.

As shown in FIG. 2, the transducer 10 has a frame 11 in the center for mounting. The converter 10 uses this frame 1
1 can be sawn into a suitable housing or navoter. The frame 11 has an annular shape and has a pair of seven flange 12 facing inward at a distance of η. In general, a thin-walled sleeve 13 without flanges is housed within the frame 11, and a flat disc-shaped diaphragm 14 is fixed on the inner central surface of said sleeve 13. Sleeve 13 is made of any suitable material, such as brass, while diaphragm 14 is likewise made of metal, such as brass.

As shown in FIGS. 2 and 3, the transducer 10 has a sleeve 13 and a diaphragm 14 arranged linearly in a direction perpendicular to the center plane of the sleeve 13 so as to generate a well-balanced sound. An electromagnetic device is installed to make it vibrate. This electric 1a device comprises a pair of coils 15.16 equally wound on the sleeve 13 symmetrically with respect to the diaphragm 14, and a pair of magnetostatic circuits 17.18 also arranged symmetrically with respect to the diaphragm 14. There is. The coils 15, 16 are wound equally and uniformly around the sleeve 13 and generate there an electromagnetic force of equal m and in the same direction depending on the alternating current supplied to the coils.

As shown in FIG. 4, the equivalent winding coils 15, 16 are wound so that they are mirror images of each other. In the figure, only two turns are shown for each coil for the purpose of clarifying the winding direction. Each coil 15.16 has a pair of terminals or leads 19.19-. 20°20-, extending from the sleeve 13 to a suitable common tap in the frame 11. Additionally, the current input terminals 19', 20' of each coil are located below the wound coil. Electrical signals are connected to terminals 19-19-. in taps (not shown) from a suitable common power source (not shown). 20. By supplying 20-
Coils 15,16 are driven in parallel. Due to the symmetrical arrangement as shown, each coil 15,16 carries an input current of equal (rl).

In this example, the current terminals for the two coils are drawn as if they were right next to each other.

The various arrangements of terminals 19, 19' relative to terminals 20, 20- determine manufacturing methods and signal conversion requirements.

In FIG. 2, magnetic circuits 17,18 are spaced within frame 11 and adjacent flange 12. In FIG. Each of the magnetic circuits 17, 18 has a pair of concentric pole rings 21, 22 with a gap between them. A pole ring 21.22 is arranged around each coil 15.16. One pole ring 21 is, for example, S14'-CI
II, while the other pole ring 22 is sewn with N-pole binding. In addition, each magnetic circuit 17,18 has an annular magnet 23 fixed to the outer pole ring 22, a transfer ring 24 fixed to the inner pole ring 21, and a link between said magnet 23 and the transfer ring 2.
It has an annular transmission plate 25 fixed to 4.

As shown, the transfer plate 25 defines a circular opening in communication with the diaphragm 14.

The pole rings 21, 22 form an air gap in which the sleeve 13, each coil 15, 16 is located, and the magnetic field lines flow across it.

In this way, the magnetic flux flows between the pole rings 21 and 22 via the magnet 23, the transmission plate 25, and the transmission ring 24. In this configuration, the magnet 23, the pole ring 21.22
, and the magnetic flux transmission plate 25 is made of a low-loss magnetic material.

The transmission ring 24 is made of cast iron.

A pair of elastic pads 26 made of, for example, compressible Ill, are fitted over 171 of the pole ring 21 to center the diaphragm 14. During operation, these pads 26 have sufficient resiliency to avoid imparting a damping effect to the reciprocating motion of the diaphragm.

In operation, the human power signal is passed through the two coils 15. in the form of an alternating current.
16 terminals 19.19-. 20. Supplied at 20-.

The signal is then split into two equal currents, which pass through the two coils 15.16 and interact with the magnetostatic field lines generated across the polar ring 21.22. the result,
Ti that moves each coil 15°16 and therefore the sleeve 13
Magnetic force is generated. Since these forces are in the same direction, ie, in the jt direction, for example, if it is rightward in FIG. 2, the sleeve 13 and the force flange 14 will move to the right. When the direction of the current is reversed, the direction of the electromagnetic force is also reversed.

The sleeve 13 and diaphragm 14 then move to the left in FIG. In this way, a linear reciprocating motion is generated in the diaphragm.

Note that the width of the static magnetic field and the magnetic flux density are conserved in the dimensions and width of each coil 15.16.

In one preferred embodiment, the inner pole ring 21
has an outside diameter of 3.593 inches (9,1260), while the outer pole ring 22 has an inside diameter of 3.625 inches (9,1260).
, 208n), and there is an annular gap of 0.032 inches (0.081o++) between them. sleeve 1
3 has an inner diameter of 3.60 inches (9,162cIII), and the outer diameter of coil 15.16 is 3.643 inches (9,162cIII).
, 2531), there is a gap of 0.032 inch (0.081 cm) between the outer pole ring 22 and the outer pole ring 22.

The coil is made of wire 0.003 inch (0.008 cm) in diameter. Two coils 15.16 and two magnetic circuits 17.18 to drive the diaphragm 14.
Balanced movement can be obtained by using the 22 coils 15, 16, and 1 magnetic circuit, or two magnetic circuits 17, 18 arranged symmetrically. If only one coil is used, an unbalanced force will be generated. This force imbalance, in turn, prevents maximum motion from the current.

, when two equivalent coils 15, 16 are used in parallel, the length through which the current flows is shorter and therefore the time is shorter than when they are connected in series and used as a single conductor. In other words, the time the current flows through the coil is halved. A converter incorporating a parallel arrangement of coils in this way results in an increase in efficiency with respect to time.

As described above, the present invention provides a transducer 111 that can vibrate a diaphragm in a well-balanced manner and thereby generate undistorted sound waves when used as a loudspeaker.

The transducer 10 may be fitted with a suitable grid-like diffusion cover at its frontage to diffuse the generated sound waves. These covers can be attached by any known method.

This example is illustrative and not limiting. That is, this invention can be modified and implemented in any way as long as it does not depart from its spirit or nature, and its scope is limited only by the scope of the claims.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a transducer constructed in accordance with the present invention;
2 is a cross-sectional view of the transducer of FIG. 1, FIG. 3 is an enlarged view of the sleeve and coil of the transducer of FIG. 1, and parts related to the magnetic circuit, and FIG. It is a layout diagram for winding. 10...Converter 11...Frame 13...Sleeve 14...Diaphragm IS, IS...Coil 17.18...Magnetic circuit 19.19', 20.20'...・Terminal 21.22...
・Pole ring 23...Magnet 24...Transmission ring 25...Transmission plate

Claims (7)

[Claims] (1) A transducer having a sleeve 13 and a diaphragm fixed thereto on the inner central surface of the sleeve 13, wherein the sleeve 13 and the diaphragm are fixed to the sleeve 13 on the inner central surface of the sleeve 13 to produce a balanced and undistorted sound. A transducer characterized in that it has an electromagnetic device arranged in mirror symmetry with respect to said sleeve 13 for linearly reciprocating movement of said sleeve 13. (2) The electromagnetic device includes a pair of coils 15, 16 wound around the sleeve 13 so as to have mirror image symmetry with respect to the central plane, and a pair of magnetic circuits 17, 18 arranged symmetrically with respect to the central plane. and a device for forming the
The coils 15, 16 are equally wound around the sleeve so as to produce electromagnetic forces of equal magnitude and direction in response to the alternating current supplied to them, and each of the magnetic circuits 17, 1
A transducer according to claim 1, characterized in that a coil (8) is arranged for each of said coils (15, 16). (3) Each of the magnetic circuits 17 and 18 has a pair of pole rings 21 and 22 arranged concentrically apart from each other, and one end of the sleeve 13 is arranged concentrically between the pole rings. A converter according to claim 2, characterized in that: (4) Each of the magnetic circuits 17 and 18 is connected to the pole ring 2.
an annular magnet 23 fixed to one of the pole rings 21 and 22; and a transmission ring 24 fixed to the other of the pole rings 21 and 22.
and an annular transmission plate 25 fixed to the magnet 23 and the transmission ring, the transmission plate 25 forming an opening connected to the diaphragm 14. Transducer as described. (5) The electromagnetic device includes a pair of coils 1 equally wound on the sleeve 13 in mirror-image symmetry with respect to the central plane.
5. The converter according to claim 4, wherein the converter has AC currents supplied from a common power source in parallel. (6) The electromagnetic device includes a first coil 15 wound around the sleeve 13 on one side of the central plane, and a magnetic device arranged around the first coil 15 on one side of the central plane. a first device 17 forming a circuit; a second coil 16 wound on the sleeve 13 in mirror symmetry with the first coil 15 on the opposite side of the central plane; a second device 18 on the opposite side forming a magnetic circuit around said second coil 16;
a common alternating current source connected to the coil 15 and the second coil 16, the first coil 15 having a pair of terminals 19, 19' extending from the sleeve 13;
This causes an alternating current to flow through the first coil 15 to generate an electromagnetic force therein, and a pair of terminals 20 from which the second coil 16 extends from the sleeve 13;
20', whereby an alternating current is passed through the second coil 16, and an electromagnetic force equal to and in the same direction as the electromagnetic force in the first coil 15 is generated therein. Converter according to claim 1. (7) The electromagnetic device includes first and second magnetic circuits 17 and 18.
, first and second coils 15 and 16 attached to each end of the sleeve 13, and a frame 1 that holds the first and second magnetic circuits so that they are mirror images of each other.
1, each magnetic circuit having a permanent magnet 23 and at least one magnetic flux transmission element 21, 22, 24, 25 forming an elongated annular air gap;
Magnetic flux is transmitted to the sleeve 13 disposed within the air gap, and roughly the coils 15, 16 are wound in equal mirror image relation to each other to transmit alternating current from a common power source in parallel. Characteristic claim 1
Converter described in section.