JPH0446498A - Bi-directional electrodynamic acoustic transducer - Google Patents

Abstract

PURPOSE:To enable thin structure and to reduce the number of parts by magnetizing magnets connected to each diaphragm respectively provided on one side and on the other side to the same polarity. CONSTITUTION:A frame 1 is formed by connecting two identical shaped ones formed to reverse circular truncated cone shape with a cylindrical stand member 1a on the bottom and forming them to be in an opening state in the right and the left direction along the identical axial center. On the outer periphery of the stand member 1a of this frame 1, a coil 2 for driving is wound. In the inside of the coil 2 composed of this two winding wires, a bobbin 7 is symmetrically installed through a damper 9 to a center line A, and a columnar or annular magnet 5 is provided as a movable magnet at a position respectively corresponding to a first and a second winding wires of the coil 2 on the outer peripheral surface of these bobbins 7. The magnets 5 equipped with the bobbins 7 on both sides are arranged to be the same polarity. A diaphragm 3 is fixed in the opposite end part arranged the magnets 5 of such bobbins 7.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a moving magnet type bidirectional electrodynamic acoustic transducer.

(Prior Art) Conventionally, this type of bidirectional electrodynamic acoustic transducer has two dynamic transducers whose centers are arranged on the same line on the front and rear surfaces of the speaker box 18, as shown in FIG. One electroacoustic transducer 23 was attached to each.

This electrodynamic acoustic transducer 23 has a magnetic circuit section consisting of a yoke 19, a magnet 15, a plate 20, etc. fixed to the rear outside of the frame 11 of an inverted conical white cane, and is composed of the yoke 19 and the plate 20. A bobbin 17 with a coil 12 wound on the outside is supported within a magnetic gap via a damper 22, and the bobbin 17 supported by the damper 22
A diaphragm 13 is provided at the end of the diaphragm 13 , and the periphery of the diaphragm 13 is attached to the outer periphery of the frame 11 via edges 16 and fixed via gaskets 4 . In addition, 21 in the figure is a center cap.

Such an electrodynamic acoustic transducer 23 requires at least four wires (not shown) for transmitting a signal current from the outside to the coil 12.

(Problem M to be solved by the invention) In the above-mentioned bidirectional electrodynamic acoustic transducer, the magnetic circuit parts are each independent and a plurality of them are used, so it is difficult to make it flat and compact, and the weight is also low. It had the disadvantage of being heavy.

In addition, there are few commonly used parts, the structure is complex, the number of parts is large, and the cost is high.

The present invention has been made in view of the above circumstances, and its purpose is to provide a moving magnet type that can be made thinner, reduce the number of parts, have a simple structure, and be manufactured at low cost. The present invention aims to provide a bidirectional electrodynamic acoustic transducer.

(Means for Solving the Problems) In order to achieve the above object, a bidirectional electrodynamic acoustic transducer of the present invention is provided on one side of a moving magnet type bidirectional electrodynamic acoustic transducer. A cylindrical or annular magnet, whose inner and outer peripheries are magnetized to N and S poles, respectively, is fixed to the center of a cone or dome-shaped diaphragm,
A cone-shaped or dome-shaped diaphragm similar to that described above is provided on the opposite side of the electrodynamic acoustic transducer in which a driving coil is arranged on the inner or outer periphery of the magnet, and the diaphragm is It is characterized in that a cylindrical or annular magnet is provided at the center, and the polarity of this magnet is the same as that of the above-mentioned magnet.

(Function) In the bidirectional electrodynamic acoustic transducer configured as described above, the magnets coupled to the diaphragms provided on one side and the other side are respectively magnetized with the same polarity. Even if there is a large input that exceeds the amplitude limit of the edge because the magnets repel each other, it is possible to generate bidirectional sound without generating noise.

Furthermore, since some of the magnetic circuit components are shared, the number of parts can be reduced accordingly, and the device can be made thinner.

(Embodiment) Hereinafter, an embodiment of the present invention will be explained with reference to FIG. 1. In FIG. They are connected by a cylindrical base member 1a and formed into a cane shape that opens left and right along the same axis. And the base member of this frame l! A driving coil 2 is mounted on the outer periphery of a. This coil 2 is started as a first winding from the end face of one frame, is wound up to the center of the base member 1a in the axial direction, and is pulled out to indicate an intermediate position at the center of the base plate 1a. The first winding is terminated at the intermediate tap 2a. The second winding extended to the intermediate tap 2a is started from the center of the base member 1a, and is wound as a coil having the same diameter and length as the first winding in a range on the other frame end surface. At the end of the volume, in the 7th episode, it was reprinted as 2b@ and ended.

The winding start of the 11th wire is taken out to the outside of the speaker box 8 as a winding start tamp 2C.

Inside the coil 2 consisting of these two windings, a bobbin 7 is installed symmetrically with respect to the center line A via a damper 9, and a cylindrical or annular magnet 5 is attached to the outer peripheral surface of the bobbin 7. , are provided as movable magnets at positions corresponding to the first winding and the second winding of the coil 2, respectively. These magnets 5 have N and S poles on the inner and outer peripheries, and the magnets 5 provided on the left and right bobbins 7 are arranged so as to have the same polarity. A diaphragm 3 is fixed to the opposite end of the bobbin 7 from which the magnet 5 is disposed, and an edge 6 is attached to the outer peripheral surface of the diaphragm 3.The outer peripheral surface of the edge 6 is connected to the frame. The flange portion 1b of the frame 1 is fixed to the flange portion 1b of the speaker box 8 via a gasket 4, and the flange portion 1b of the frame 1 is fixed to the front and rear front surfaces of the speaker box 8.

In the above explanation, the magnet 5 of the same polarity is attached to the outer peripheral surface of the bobbin 7.
, a coil 2 is provided outside the coil 2, a signal current is input to the coil 2, and this human power causes the bobbin 7 to vibrate in opposite directions to generate sound from the diaphragm 3. Although the converter has been described, the same effect can be obtained by disposing magnets of the same polarity on the inner circumferential surface of the bobbin and disposing the magnets within the inner circumferential surface.

As described above, in the bidirectional electrodynamic speaker of the present invention, the coil 2 is shared, and the yoke and plate parts are completely unnecessary, which reduces the weight. Since the magnets 5 have the same polarity, even if there is a large input to the coil 2 and the bobbin 7 has a large amplitude, a repulsive force will be generated and they will not come into contact with each other.
It is characterized by the fact that the inconvenience of generating noise that exceeds the amplitude limit of the engine is less likely to occur. In addition, it is possible to produce bidirectional sound without being affected even in a high-pressure environment. Furthermore, the coil part has a completely waterproof structure,
By constructing the diaphragm with a water-resistant film or the like, it can also be used as an underwater speaker.

(Effects of the Invention) As explained above, the bidirectional electrodynamic acoustic transducer of the present invention is a moving magnet type bidirectional electrodynamic acoustic transducer. A cylindrical or annular magnet whose inner and outer circumferences are magnetized to N and S poles, respectively, is fixed to the center of the diaphragm.
A cone-shaped or dome-shaped diaphragm similar to that described above is provided on the opposite side of the electrodynamic acoustic transducer in which a driving coil is arranged on the inner or outer periphery of the magnet, and the diaphragm is A cylindrical or annular magnet is provided at the center, and the polarity of this magnet is the same as that of the magnet described above, so it can be made thinner, the number of parts can be reduced, and the structure can be simplified and manufactured at low cost. There is an advantage that it can be done.

In particular, in the bidirectional electrodynamic acoustic transducer with this configuration, the magnets installed on the bobbin have the same polarity on the left and right sides, so even if a large amplitude is generated due to a large input, noise will be generated. It also has the advantage of preventing

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a bidirectional electrodynamic acoustic transducer according to an embodiment of the present invention, and FIG. 2 is a conventional example. 2... Drive coil 3... Vibration plate 5... Magnet,

Claims (1)

[Claims] In a moving magnet type bidirectional electrodynamic acoustic transducer, there is a circle in the center of a cone or dome-shaped diaphragm provided on one side, the inner and outer circumferences of which are magnetized to N and S poles, respectively. An electrodynamic acoustic transducer is formed by fixing a columnar or annular magnet and disposing a driving coil around the inner or outer periphery of the magnet.The driving coil is also used on the opposite side of the electrodynamic acoustic transducer to form a cone or dome shape similar to the above. A bidirectional electrodynamic acoustic device characterized in that a diaphragm is provided, a cylindrical or annular magnet is provided at the center of the diaphragm, and the polarity of this magnet is the same as that of the above-mentioned magnet. converter.