JPH0731665Y2 - Electromechanical vibration converter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an electromechanical vibration converter for converting an electrical signal such as a voice signal into a mechanical vibration, and in particular, for an electro-acoustic device for perceiving deep bass with the body. A mechanical vibration converter.

[Conventional technology]

The electromechanical vibration converter in the sensory acoustic device is, for example, the third
It is configured as shown in the figure. In the figure, reference numeral 1 denotes a signal source, the output of which is wound around a bobbin 3 and supplied to a voice coil 4 fixed to a case 2. 5 has one end fixed to the case 2 and the other end having a magnetic circuit 6
It is a damper fixed to. The magnetic circuit 6 is composed of a permanent magnet 7, a back plate 8, a pole piece 9 and a top plate 10. The magnetic flux generated by the permanent magnet 7 is the top plate 10, the pole piece 9, the back plate 8 or vice versa. It is designed to cycle along the route. The voice coil 4 is arranged in a magnetic gap 11 formed between the top plate 10 and the pole piece 9.

When an audio signal such as a musical tone signal, especially its low temperature range component, is supplied to the voice coil 4 from the signal source 1, an electromagnetic force is generated, and the magnetic circuit 6 supported by the damper 5 and the case 2 are relatively moved. Vibration occurs. Therefore, when the case 2 is attached to a chair, a sofa, a bed, or the like (not shown), the vibration from the case 2 is transmitted to the body, and the body can perceive low sound, particularly heavy cold.

[Problems to be solved by the invention]

By the way, in the electromechanical vibration converter in such a body acoustic device, a relatively large current flows to the voice coil 4 for a long time because the heavy bass needs to be reproduced, and its temperature rises. There is a risk that the bobbin 3 may expand and fall off the bobbin 3. As a result, there is a drawback that the allowable input as the converter is limited to a small value.

[Means for solving problems]

FIG. 1 shows the configuration of an electromechanical vibration converter according to the present invention. In the figure, parts corresponding to those in FIG. 3 are designated by the same reference numerals, and detailed description thereof will be omitted.
In the present invention, a damper 21 made of an elastic material such as rubber is provided so that an air chamber 20 is formed between the back plate 8 and the case 2 (the elastic modulus of the damper 21 is set appropriately, and the damper 5 is provided). May be omitted). Reference numeral 22 is a hole provided in the back plate 8 between the permanent magnet 7 and the pole piece 9, and the air in the air chamber 20 passes through the hole 22 and the magnetic gap.
It is possible to flow in and out from 11th. Reference numeral 23 denotes a hole provided substantially at the center of the pole piece 9 so that the air in the air chamber 20 can flow in and out in front of the pole piece 9.

[Action]

When a musical tone signal, particularly a low-pitched component thereof, is supplied from the signal source 1 to the voice coil 4, an electromagnetic force is generated because the voice coil 4 is suspended in the magnetic gap 11. As a result, since the magnetic circuit 6 is supported by the damper 5 with respect to the case 2, relative vibration is generated between the case 2 and the magnetic circuit 6, and this vibration is transmitted to the chair or the like to which the case 2 is fixed. Thus, a user sitting on a chair or the like can perceive the bass, particularly the deep bass, with the body. If other components of the musical tone signal are emitted toward the user from a speaker (not shown) or the like, the user can enjoy the musical tone with a more realistic feeling.

When the magnetic circuit 6 vibrates relative to the case 2, the volume of the air chamber 20 changes corresponding to the vibration.
As a result, the air in the air chamber 20 flows in and out through the holes 22 and 23, and the flow of this air is also transmitted to the magnetic gap 11 suspended in the voice coil 4. Therefore, the heat generated from the voice coil 4 heats the surrounding air, but the heated air flows to disperse the heat, transfer it to the case 2, etc., and dissipate it from the case 2 etc. to the outside. So
The temperature of the voice coil 4 and its surroundings does not rise so much.
In order to carry out such an effect more efficiently, the hole 22 is provided so as to be located on the extension line of the relative vibration direction of the virtual cylinder formed by the magnetic gap 11. Therefore, the air discharged from the air chamber 20 through the hole 22 rises linearly and can pass through the magnetic gap 11.
Air that has entered through 11 is allowed to linearly descend, pass through holes 22 and flow into the air chamber 20.

〔Example〕

FIG. 2 shows another embodiment of the present invention. In the figure, parts corresponding to those in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted. In this embodiment, a weight 31 is provided behind the back plate 8 and is supported by a damper 21 to form an air chamber 30. The weight 31 and the magnetic circuit 6 are capable of relative vibration. 32 is a hole provided in the weight 31. Reference numerals 33 and 34 are holes provided on the front surface and the rear surface of the case 2, respectively. The damper 21 and the weight 31 constitute a so-called dynamic vibration absorber.

Also in this embodiment, when a musical tone signal flows through the voice coil 4, since the magnetic circuit 6 and the weight 31 are connected via the damper 21, relative vibration occurs between them and the air chamber corresponding to the signal. The volume of 30 changes. Therefore air is in each hole
It can be freely accessed via 22, 23, 32, 33, 34. In this case, the air inside the case 2 can directly flow to the outside, which is more effective in radiating the heat to the outside (of course, holes may be provided in the case 2 also in the case shown in FIG. 1). . However, in any of the configurations shown in FIG. 1 and FIG. 2, each hole 22, 23, 32, 33, 34 also controls the sharpness Q of the resonance frequency of relative vibration, and therefore, should be made too large. If it passes, the value of Q will decrease, so its size must be set to an appropriate value.

〔effect〕

As described above, in the present invention, the air chamber is provided outside the magnetic circuit so that the volume of the air chamber changes in response to the relative vibration, and the volume change causes the air flow to the magnetic gap part where the voice coil is suspended. The heat of the voice coil and its surroundings can be dissipated, the temperature rise of the voice coil can be suppressed, and the allowable input to the converter can be increased.

[Brief description of drawings]

FIG. 1 is a sectional view of an electromechanical vibration converter of the present invention, FIG. 2 is a sectional view of another embodiment, and FIG. 3 is a sectional view of a conventional device. 2 ... Case, 3 ... Bobbin 4 ... Voice coil, 5, 21 ... Damper 6 ... Magnetic circuit, 11 ... Magnetic gap 20, 30 ... Air chamber, 22, 23, 32, 33, 34 ... … Hole 31 …… Weight

Claims (2)

[Scope of utility model registration request] 1. A case (2), a voice coil (4) fixed to the case (2), and a top plate () arranged at a position where the voice coil (4) is suspended in a magnetic gap (11). 10), a pole piece (9), a back plate (8) connected below the pole piece (9), the top plate (10), and a permanent magnet (7) provided between the back plate (8). ) And a magnetic circuit (6)
And a damper (5) for supporting the magnetic circuit (6) so that it can vibrate relative to the case (2), the case (2) and the back plate (8).
And a damper (21) for supporting the magnetic circuit (6) so that the magnetic circuit (6) can vibrate relative to the case (2), and the volume of which changes according to the relative vibration of the magnetic circuit (6). Room (2
0) is formed, a hole (22) is provided in the back plate (8) of the magnetic circuit (6), and when the volume of the air chamber (20) is changed, the air in the air chamber (20) is changed to the hole. An electromechanical vibration converter, characterized in that it passes through (22) and the magnetic gap (11) to enter and exit. 2. A hole (2) is formed substantially at the center of the pole piece (9).
3) is provided, and when the volume of the air chamber (20) changes in response to relative vibration of the magnetic circuit (6), the air chamber (20)
2. The electromechanical vibration converter according to claim 1, wherein said air is allowed to flow in and out through the holes (22, 23) and the magnetic gap (11).