JPS6114720B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dynamic speaker having a diaphragm with at least a flat front surface.

FIG. 1 is a longitudinal sectional view of a conventionally known dynamic speaker equipped with a flat diaphragm. In FIG. 1, a flat plate diaphragm 1 having a honeycomb structure is coupled to a frame 3 via edges 2. In FIG. A magnetic circuit consisting of a yoke 4, a pole piece 5, a magnet 6, and a center pole 7 is arranged on the back side of the frame 3, and a voice coil bobbin 8 attached to the back of the diaphragm 1 is connected to the diaphragm 1 by this magnetic circuit.
A driving magnetic flux is applied to the voice coil 9 of. The voice coil bobbin 8 is coupled to the frame 3 via a damper 10.

FIG. 2A is a partial vertical sectional view showing a method of coupling the diaphragm 1 and the voice coil bobbin 8 of FIG.
A bobbin 8 is directly attached to the top with an adhesive 14. In this case, the diameter of the bobbin 8 is determined such that the bonding position is a node of the divided vibration of the diaphragm 1, thereby suppressing unnecessary divided vibration.

In the structure shown in Fig. 2A, the contact area between the diaphragm and the bobbin is small, so the diaphragm 1 is easily bent due to concentrated load, and the stress is dispersed as shown by the arrow in Fig. 2A. Since the sound waves are transmitted to the front skin 12a, the distance over which the sound waves travel differs from part to part of the diaphragm 1, which tends to deteriorate the sound quality.

FIG. 2B is a longitudinal cross-sectional view of a conventionally known joint that is an improvement on FIG. 2A, and in this example, the honeycomb core 1
3 and attach the connecting pin 15 to the front skin 12a, and attach the bobbin 8 to the connecting pin 15 with adhesive 1.
It is joined at 4. For example, four connecting pins 15 are used, and the pins are placed at the nodes of the divided vibration of the diaphragm 1. In this case, since the stress is directly transmitted to the front skin 12a, almost 100% of the information is transmitted to the front skin 12a. However, since the stress is also transmitted to the rear skin 12b via the adhesive 14, the diaphragm 1 has a double sound source consisting of the front skin 12a and the rear skin 12b when viewed from the front of the speaker. The acoustic energy emitted from the rear skin 12b that is equal to or greater than the energy from the front skin 12a is delayed by the thickness of the honeycomb core 13, resulting in a deterioration of the reproduced sound quality.

FIG. 2C is a partial longitudinal cross-sectional view of a further improved conventional coupling part. In this example, a hole is made in the diaphragm 1, a cup member 16 is attached to the front skin 12a, and a bobbin 8 is attached to this cup member 16. . In this case, no stress is transmitted to the rear skin 12b, but a large portion of the honeycomb core 13 is lost, resulting in a decrease in the rigidity of the diaphragm 1, making it difficult to use this coupling structure in large-area woofers. Even if it were possible, it could not be used as a squawker or tweeter.

In view of the above-mentioned problems, the present invention provides a coupling structure that prevents the driving stress of the voice coil bobbin from being transmitted to the rear skin as much as possible, and that can be applied to a diaphragm having a relatively small area.

Embodiments of the present invention will be described below with reference to the drawings.

In this embodiment, the above-mentioned object is achieved by improving the conventional coupling structure shown in FIG. 2B.

FIG. 3 is a partial vertical cross-sectional view (cross-section taken along the - line in FIG. 4) showing a coupling structure between a diaphragm and a voice coil bobbin according to an embodiment of the present invention, and FIG. 4 is a cross-sectional view taken along the line - It is a diagram. As shown in Figures 3 and 4, 4 made of carbon, aluminum, etc.
Connecting pins 15 spaced approximately 90 degrees apart pass through the honeycomb core 13 and are attached to the front skin 12a. At the connecting pin penetration part of the rear skin 12b,
Since the opening 18 is provided, the rear skin 12
b does not contact the connecting pin 15 at all. The connecting pin 15 protrudes somewhat beyond the surface of the rear skin 12b, and the voice coil bobbin 8 is attached to the end thereof with adhesive 1.
9 is also firmly attached. Therefore, rear skin 1
A gap 20 is formed between 2b and the end surface of the bobbin 8, and the rear skin and the bobbin are not in contact with each other at all. As a result, the driving force is not transmitted to the rear skin 12b from the bobbin 8 or the connecting pin 15, so the diaphragm 1 does not become a double sound source.
You can get extremely clear and high-resolution playback sound. Note that a certain effect can be obtained even when the rear skin 12b and either the bobbin 8 or the connecting pin 15 are not connected.

If the mechanical strength of the bobbin 8 becomes a problem due to not bonding the bobbin 8 to the rear skin 12b, a ring-shaped reinforcing material 24 may be attached as shown in FIG. 3, or ribs may be provided during bobbin molding. It's okay.

Next, FIG. 5 is a partial vertical sectional view similar to FIG. 3 showing another embodiment of the present invention. In this example,
In the connection structure shown in FIG. 3, the end surface of the bobbin 8 is bonded to the rear skin 12b with an adhesive 21 without providing a gap 20. This adhesive 21 can be, for example, a rubber-based adhesive that is soft (low rigidity) in a hardened state, and thereby can sufficiently attenuate the force transmitted from the end surface of the bobbin 8 to the rear skin 12b. It is also possible to prevent a decrease in the mechanical strength of the bobbin 8 itself. The bobbin 8 and the connecting pin 15 are bonded together using a hard (highly rigid) adhesive 19, such as an epoxy adhesive.

Next, FIG. 6 is a longitudinal sectional view showing a modification of the embodiment shown in FIG. 3, and in this example, a gap 20 is provided between the bobbin 8 and the rear skin 12b.
In order to ensure the mounting strength of the connecting pin 15, an adhesive 2 is applied between the connecting pin 15 and the rear skin 12b.
It is joined by 2. In this case, the rear skin 12b
Although some driving stress is transmitted through the connecting pin 15, the amount is minute and has little effect on sound quality. Note that the adhesive 22 is preferably soft, but may be hard.

Next, FIG. 7 shows a compromise between the embodiments shown in FIGS. 3 and 5, in which a plurality of notches 23 are provided on the end face of the bobbin 8 in place of the gaps 20 in FIG. 3. The end surface of the bobbin 8 other than the notch 23 is attached to the rear skin 12 with a soft adhesive 21 as shown in FIG.
It is glued to b. Further, the rear skin 12b and the connecting pin 15 are kept out of contact by the opening 18. In FIG. 7, the adhesive 21 may be the same hard material as the adhesive 19.

FIG. 8 shows a modification of FIG. 7, in which a soft adhesive 21 is partially used on the peripheral end surface of the bobbin 8 in place of the notch 23 in FIG.
The mechanical connection between the bobbin 8 and the bobbin 8 is weakened.

In each of the above-mentioned embodiments, a rod-shaped connecting pin 19 is used, but a pipe-shaped one may also be used. Furthermore, the diaphragm 1 is not limited to one having a honeycomb structure, and can also be applied to, for example, a cone-shaped diaphragm filled with a foam material. Further, the present invention can also be applied to a multi-point drive type flat diaphragm speaker in which a plurality of voice coils are provided on one diaphragm.

As described above, the present invention provides mechanical coupling between the rear skin layer of the diaphragm and the coupling member (coupling pin) and/or the voice coil bobbin through non-coupling or weak coupling (for example, using a soft adhesive). state. Therefore, the driving force of the voice coil transmitted to the rear skin layer via the voice coil bobbin or the connecting member can be reduced to zero or sufficiently attenuated, thereby substantially driving only the front skin layer of the diaphragm. Since the power can be transmitted, there is no double diaphragm sound source, and extremely clear and high-resolution reproduced sound can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a conventionally well-known dynamic speaker equipped with a flat diaphragm, and FIGS.
Fig. C is a partial vertical sectional view showing a conventional example of a method of coupling a diaphragm and a voice coil bobbin, and Fig. 3 is a partial vertical sectional view showing a coupling structure of a diaphragm and a voice coil bobbin according to an embodiment of the present invention. , Figure 4 is the third
Fig. 5 is a partial vertical sectional view similar to Fig. 3 showing another embodiment of the present invention, and Figs. 6 to 8 are modifications of Fig. 3 or Fig. 5, respectively. FIG. 4 is a partial vertical cross-sectional view similar to FIG. 3 illustrating an example; In addition, in the symbols used in the drawings, 1...
...Diaphragm, 8...Voice coil bobbin, 9...Voice coil, 12a...Front skin, 12b...
Rear skin, 13... Honeycomb core, 15... Connecting pin, 18... Opening, 20... Clearance, 21...
...It's an adhesive.

Claims (1)

[Claims] 1. A rod-shaped or pipe-shaped connecting member is attached to the front skin layer of a diaphragm whose front surface is at least flat, a voice coil bobbin is coupled to this connecting member, and the driving force of the voice coil is applied to the front skin layer. In the dynamic speaker, the rear skin layer of the diaphragm, the connecting member and/or
Alternatively, a dynamic speaker characterized in that the mechanical connection between the voice coil bobbin and the voice coil bobbin is non-coupled or weakly coupled. 2. The dynamic speaker according to claim 1, wherein a gap is provided between the rear skin layer and the connecting member. 3. The dynamic speaker according to claim 1, wherein the rear skin layer and the connecting member are bonded together in a hardened state with a soft adhesive. 4. The dynamic speaker according to claim 1, wherein a gap is provided between the rear skin layer and the voice coil bobbin. 5. The dynamic speaker according to claim 1, wherein the rear skin layer and the voice coil bobbin are bonded to each other by a soft adhesive in a hardened state. 6. The dynamic device according to claim 1, wherein a plurality of notches are provided in the end face of the voice coil bobbin so that the rear skin layer and the voice coil bobbin are partially adhesively bonded. speaker. 7. The dynamic speaker according to claim 1, wherein the rear skin layer and the end surface of the voice coil bobbin are partially adhesively bonded.