JP2014057137A - Shock mount member and dynamic microphone using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dynamic microphone employing a cancellation method having optimum vibration-noise performance according to a model by configuring a shock mount member so as to enable its hardness to be selected easily.SOLUTION: A shock mount member 1 is formed in a flat shape using a rubber material, and has an annular outer peripheral body 1a and an annular inner peripheral body 1b integrally formed via a plurality of coupling parts 1c formed in the radiation direction, with an arcuate slit 1d formed between the outer peripheral body 1a and the inner peripheral body 1b. Also, each of the coupling parts 1c is provided with a plurality of openings 1e penetrating in the thickness direction. An outer peripheral edge 1f of the outer peripheral body in the shock mount member 1 is attached to a microphone case 31, and a hollow body 21 constituting a rear air chamber 22 of a microphone unit 11 is supported at an inner peripheral edge 1g of the inner peripheral body.

Description

  The present invention relates to a shock mount member that supports a microphone unit in a microphone case and a dynamic microphone using the shock mount member.

A dynamic microphone is also called an electrodynamic microphone because a voice coil attached to a diaphragm is placed in a magnetic gap formed in a magnetic circuit, and a voice current is generated in the voice coil by vibration of the diaphragm. .
As is well known, this dynamic microphone is suitably used as a vocal microphone. However, since the mass of a vibration system including a diaphragm including a voice coil is large, the microphone case is used by holding the microphone case by hand. Has a problem that vibration noise (touch noise) is easily generated.

Therefore, most of this type of dynamic microphone includes means for reducing the vibration noise.
As one of the means, there has been proposed a canceling method that suppresses the generation of vibration noise by canceling the inertial force generated in the diaphragm with the pressure generated in the back air chamber.

In a dynamic microphone employing this cancellation method, a hollow body constituting the back air chamber of the microphone unit is attached to the back side of the microphone unit.
The microphone unit and the hollow body are attached to the microphone case via a shock mount member made of a rubber material.

According to the dynamic microphone adopting this cancellation method, when gravity is applied in the axial direction of the microphone, for example, when the vibration system including the diaphragm and the voice coil is stopped by the inertial force, An operation occurs in which the coil attempts to move relative to the magnetic circuit.
At this time, a pressure change that occurs in the back air chamber due to the hollow body acts on the back surface of the diaphragm, and as a result, a canceling action that suppresses relative movement of the vibration system with respect to the magnetic circuit occurs. Thereby, generation | occurrence | production of vibration noise can be reduced effectively.

FIGS. 7A and 7B are a front view showing the entire configuration of a conventional shock mount member used in a dynamic microphone adopting the cancellation method described above, and a state in which it is cut at the center in the thickness direction. It is sectional drawing.
As described above, the shock mount member 1 is formed in a disc shape, that is, in a circular shape and a flat shape by a rubber material, and an annular outer peripheral body 1a and an annular inner peripheral body 1b are radially formed. It is integrally formed through the formed connecting portion 1c.

That is, between each connection part 1c formed in the above-described radial direction, an arc-shaped slit 1d is formed between the outer peripheral body 1a and the inner peripheral body 1b, and the shock mount member 1 shown in FIG. Three connecting portions 1c are formed at intervals of 120 degrees in the circumferential direction.
The outer peripheral edge 1f of the outer peripheral body 1a is attached to the inner wall surface of the microphone case, and the inner peripheral edge 1g of the inner peripheral body 1b supports the hollow body constituting the microphone unit or the back air chamber of the microphone unit. Is configured to do.

  A dynamic microphone that employs the cancellation method described above is disclosed in Patent Document 1 shown below.

JP 2012-15695 A

By the way, a CR (chloroprene) rubber material is used for the shock mount member having the above-described structure, and the hardness of the rubber material is generally controlled with a tolerance of ± 5 degrees.
However, even if the hardness of the shock mount member is within the tolerance range, it is known that there is a great variation in the effect of reducing vibration noise when actually mounted on a dynamic microphone.

FIG. 8 shows an example thereof, and shows the characteristics when a shock mount member having a different rubber hardness is used for the cancel type dynamic microphone using the shock mount member shown in FIG.
That is, in FIG. 8, the vertical axis indicates the signal-to-noise ratio (vibration noise), the horizontal axis indicates the frequency, and the characteristic a indicates an example when a shock mount member having a rubber hardness of 42 degrees is used. The characteristic b shows an example when a shock mount member having a rubber hardness of 47 degrees is used.

As can be understood from the example shown in FIG. 8, in the dynamic microphone adopting the cancellation method, when the rubber hardness of the shock mount member is increased by 5 degrees, the microphone unit and the hollow body constituting the back air chamber of the microphone unit The resonance frequency of the supported body including sine increases, and with this, the level of vibration noise clearly increases.
Therefore, if the rubber hardness that constitutes the shock mount member can be controlled more strictly, variations in vibration noise can be suppressed, but in reality, the raw material of the rubber material that constitutes the shock mount member is used. It is difficult to control the hardness.

  As described above, dynamic microphones using the cancellation method are mass-produced because even a slight variation in the hardness of the shock mount member, for example, a large variation in vibration noise due to a difference in the manufacturing lot of the shock mount member. It is difficult to stably provide a dynamic microphone having good vibration noise performance.

The present invention has been made by paying attention to the above-mentioned problems in a dynamic microphone employing a conventional cancellation method, and is configured so that the hardness of the shock mount member can be easily selected. It is an object to provide a shock mount member having a high height.
In addition, the present invention makes it possible to easily select the resonance frequency of the supported body including the microphone unit and the hollow body constituting the back air chamber of the microphone unit by using the above-described shock mount member, depending on the model. An object of the present invention is to provide a dynamic microphone having optimum vibration noise performance.

  The shock mount member according to the present invention made to achieve the above-described problem is formed in a flat shape by a rubber material, and an annular outer peripheral body and an annular inner peripheral body are integrated through a plurality of connecting portions. A shock mount member formed by molding, wherein at least one of the connecting portions connecting the outer peripheral body and the inner peripheral body is provided with at least one opening penetrating in the thickness direction. Features.

  The shock mount member according to the present invention is formed in a flat shape by a rubber material, and an annular outer peripheral body and an annular inner peripheral body are integrally formed through a plurality of connecting portions, and the outer peripheral body and the A shock mount member in which a slit is formed between the inner peripheral body and between each of the connecting portions, and at least one of the connecting portions connecting the outer peripheral body and the inner peripheral body. Further, at least one opening penetrating in the thickness direction is provided.

  In any of the shock mount members described above, it is desirable that the connecting portions are formed at equal intervals in the circumferential direction, and it is desirable that the same number of the openings be provided in each connecting portion. .

  On the other hand, the dynamic microphone according to the present invention made to achieve the above-described problem uses the shock mount member having the above-described configuration, and the outer peripheral edge portion of the outer peripheral body of the shock mount member is attached to the microphone case. In addition, a hollow body constituting a microphone unit or a back air chamber of the microphone unit is supported at an inner peripheral edge of the inner peripheral body.

  In addition, a configuration in which the connecting portion divided by the plurality of openings provided in the shock mount member is selectively cut out is employed.

According to the shock mount member having the above-described configuration, the outer peripheral body and the inner peripheral body are integrally formed of a rubber material through a plurality of connecting portions, and each connecting portion that connects the outer peripheral body and the inner peripheral body has a thickness. A configuration in which a plurality of openings penetrating in the vertical direction are provided is employed.
According to this structure, the hardness as a shock mount member is easily obtained by selectively cutting out each connecting portion divided by each opening so that the plurality of openings provided in each connecting portion communicate with each other. Can be selected. Thereby, a highly versatile shock mount member can be provided.

  Further, according to the dynamic microphone using the shock mount member having the above-described configuration, the hardness as the shock mount member can be easily selected, and therefore the microphone unit supported via the shock mount member and the back air of the microphone unit are supported. It becomes possible to easily select the resonance frequency of the supported body including the hollow body constituting the chamber. Thereby, the dynamic microphone which employ | adopted the cancellation system which has the optimal vibration noise performance according to a model can be provided.

1 is a central sectional view showing an overall configuration of a dynamic microphone according to the present invention. FIG. 2 is a front view of a shock mount member used in the dynamic microphone shown in FIG. FIG. 3 is a front view and a cross-sectional view of a state in which a part of a connecting portion of the shock mount member shown in FIG. 2 is cut away. It is the front view and sectional drawing of the state which further excised a part of connection part of the shock mount member shown in FIG. It is the front view and sectional drawing of the state which further excised part of the connection part of the shock mount member shown in FIG. It is the characteristic view which showed the change of the vibration noise when a part of connection part of a shock mount member is sequentially excised. It is the front view which showed the example of the conventional shock mount member, and sectional drawing of the state cut | disconnected in the center part of the thickness direction. FIG. 8 is a characteristic diagram showing an example of generation of vibration noise in the dynamic microphone using the shock mount member shown in FIG. 7.

  A shock mount member and a dynamic microphone using the shock mount member according to the present invention will be described based on the embodiments shown in the drawings. First, the overall configuration of a dynamic microphone adopting a cancellation method will be described and used for the dynamic microphone. The detailed configuration of the shock mount member to be used will be described later.

FIG. 1 is a sectional view showing the overall configuration of a dynamic microphone according to the present invention that employs a cancellation method.
Reference numeral 11 denotes a microphone unit. As is well known, the microphone unit 11 includes a diaphragm 12 having a voice coil and a magnetic circuit 13 having a magnetic gap in which the voice coil is arranged so as to vibrate. A peripheral side surface of a yoke constituting the magnetic circuit 13 of the microphone unit 11 is attached in a state of being fitted into a holder 14 formed in a cylindrical shape.

Further, a hollow body 21 forming a back air chamber 22 of the microphone unit 11 is connected via the cylindrical holder 14. That is, the back air chamber 22 surrounded by the hollow body 21 is configured to communicate with the back surface of the diaphragm 12 in the microphone unit 11, and an opening 23 is provided at the end of the hollow body 21. A ventilation resistor (indicated by the same reference numeral as the opening 23) is attached to the opening.
A supported body including the microphone unit 11 and the hollow body 21 is supported by a first shock mount member 1 and a second shock mount member 2 made of a rubber material, and is placed in a microphone case 31. It is attached.

The first shock mount member 1 functions to support the entire weight of the supported body including the microphone unit 11 and the hollow body 21, and is disposed at the center of gravity of the entire supported body. ing.
Further, the second shock mount member 2 seals the hollow body 21 side when the above-described canceling method is further adopted in order to prevent the supported body from rolling in the microphone case 31. It is arranged to do.

A cylindrical weight 24 is attached to the outer peripheral surface of the hollow body 21. The weight 24 is arranged to match the center of gravity of the entire supported body including the microphone unit 11 and the hollow body 21 with the fulcrum of the first shock mount member 1 described above.
As a result, the microphone unit 11 acts so that rolling in the microphone case 31 is further suppressed and vibration noise generated by the rolling of the microphone unit 11 is also reduced.
Note that reference numeral 26 in FIG. 1 denotes a sealing member for sealing the inside of the microphone case 31.

  An output connector 33 having connection pins is disposed at the lower end portion of the microphone case 31 shown in FIG. 1, and the connection pins constituting the output connector 33 are implanted in the insulating base 34 to be microphone case 31. It is arranged in the bottom of the bottom.

2 (A) and 2 (B) are a front view showing the entire configuration of the first shock mount member 1 according to the present invention and a cross-sectional view taken at the center in the thickness direction.
The shock mount member 1 is formed in a disc shape, that is, in a circular shape and a flat shape by a rubber material (CR rubber), as already described with reference to FIG. The body 1a and the annular inner peripheral body 1b are integrally formed via a connecting portion 1c formed in the radial direction.

A portion sandwiched between the connecting portions 1c formed in the radial direction between the outer peripheral body 1a and the inner peripheral body 1b is formed as an arc-shaped slit 1d. Three connecting portions 1c are formed at intervals of 120 degrees in the direction, and three arc-shaped slits 1d are formed.
In addition, a plurality of openings 1e penetrating in the thickness direction are arranged in an arc shape along the circumferential direction of each connecting portion 1c in each connecting portion 1c that connects the outer peripheral body 1a and the inner peripheral body 1b. It has been subjected.

As shown in FIG. 2, an even number of the same number of openings 1e are formed in each of the connecting portions 1c. In this example, a total of six openings 1e are provided in one connecting portion 1c. Yes. In addition, in this example, three elongate openings 1e in the radial direction are formed in a concentrated manner on both outer sides excluding the central portion of each connecting portion 1c, that is, closer to the arc-shaped slit 1d.
With this configuration, the connecting portion 1c is further divided in the circumferential direction by the elongated openings 1e.

  In the shock mount member 1 configured as described above, the outer peripheral edge 1 f of the outer peripheral body 1 a is attached to the inner wall surface of the microphone case 31. For this purpose, as shown in the cross-sectional view of FIG. 2 (B), screw insertion holes 1h are formed at three locations on the outer peripheral edge of the shock mount member 1, and are inserted through the microphone case 31. The shock mount member 1 is mounted in the microphone case 31 by screws not shown.

The shock mount member 1 is configured to support the hollow body 21 constituting the back air chamber 22 of the microphone unit 11 at the inner peripheral edge 1g of the inner peripheral body 1b.
In the example shown in FIG. 1, the first shock mount member 1 is configured to support the hollow body 21 constituting the back air chamber 22 of the microphone unit 11. 1 may be configured to support the microphone unit 11.

According to the configuration of the first shock mount member 1 described above, in each of the connecting portions 1c formed at three locations, six openings 1e are provided in the circumferential direction, and the connecting portion 1c is divided in the circumferential direction. ing. Therefore, by sequentially cutting the connecting portion 1c divided from the arc-shaped slit 1d, each opening 1e communicates with the arc-shaped slit 1d, and the arc-shaped slit as shown in FIGS. The circumferential length of 1d can be expanded in order. In FIGS. 3 to 5, reference numerals are appropriately omitted as compared with FIG. 2.
As described above, by sequentially expanding the circumferential length of the arc-shaped slit 1d, the circumferential width of the connecting portion 1c is gradually reduced, and the substantial rubber hardness of the shock mount member 1 is reduced. Become.

FIG. 6 shows vibration noise characteristics when the cancel-type dynamic microphone shown in FIG. 1 is configured using the shock mount member 1 having the configuration shown in FIGS. 2 to 5 according to the present invention. The vertical axis represents the signal-to-noise ratio (vibration noise), and the horizontal axis represents the frequency. That is, the characteristic a shown in FIG. 6 shows the vibration noise characteristic when the shock mount member 1 shown in FIG. 2 is used, and the characteristics b to d shown in FIG. 6 are the shocks shown in FIGS. The vibration noise characteristic at the time of utilizing the mount member 1 is shown.
The characteristic e shown in FIG. 6 shows the frequency response of the microphone when the shock mount member 1 shown in FIG. 2 is used.

As can be understood from the vibration noise characteristics shown in FIG. 6, the resonance of the supported body including the microphone unit and the hollow body constituting the back air chamber is obtained by sequentially cutting the connecting portion 1 c divided by the plurality of openings 1. The frequency can be lowered in order, and the level of vibration noise can be adjusted.
Therefore, by using the shock mount member according to the present invention for a dynamic microphone adopting the cancellation method, it becomes possible to adjust the vibration noise level according to each model. The effect as described can be obtained.

As shown in FIGS. 2 to 5, the shock mount member according to the present invention shows an example in which the connecting portions 1c divided by the plurality of openings 1e are cut out in pairs from the side closer to the slit 1d. However, it is possible to adjust the level of vibration noise at a finer level by cutting off only one of the paired connecting portions 1c.
Further, the level of vibration noise can be adjusted by cutting the connecting portion 1c so that the openings 1e communicate with each other without cutting the connecting portion 1c divided by the opening 1e in order from the side closer to the slit 1d. You can also.

DESCRIPTION OF SYMBOLS 1 1st shock mount member 1a Outer peripheral body 1b Inner peripheral body 1c Connection part 1d Slit 1e Opening 1f Outer peripheral edge 1g Inner peripheral edge 1h Screw insertion hole 2 Second shock mount member 11 Microphone unit 12 Diaphragm 13 Magnetic circuit 14 Holder 21 Hollow body 22 Back air chamber 23 Opening (ventilation resistor)
24 Weight 26 Sealing member 31 Microphone case 33 Output connector 34 Insulation base

Claims (6)

A shock mount member formed in a flat shape by a rubber material, and an annular outer peripheral body and an annular inner peripheral body are integrally formed through a plurality of connecting portions,
The shock mount member according to claim 1, wherein at least one of the connecting portions connecting the outer peripheral body and the inner peripheral body is provided with at least one opening penetrating in the thickness direction. It is formed in a flat shape by a rubber material, and an annular outer peripheral body and an annular inner peripheral body are integrally formed through a plurality of connecting portions, and the connection between the outer peripheral body and the inner peripheral body and each of the connections. A shock mount member in which slits are formed between the parts,
The shock mount member according to claim 1, wherein at least one of the connecting portions connecting the outer peripheral body and the inner peripheral body is provided with at least one opening penetrating in the thickness direction.   The shock mount member according to claim 1 or 2, wherein the connecting portions are formed at equal intervals in the circumferential direction.   The shock mount member according to any one of claims 1 to 3, wherein the same number of the openings are provided in each of the connecting portions. A dynamic microphone using the shock mount member according to any one of claims 1 to 4,
An outer peripheral edge of the outer peripheral body of the shock mount member is attached to a microphone case, and a hollow body constituting a microphone unit or a back air chamber of the microphone unit is supported at an inner peripheral edge of the inner peripheral body. Dynamic microphone.   The dynamic microphone according to claim 5, wherein the connecting portion divided by a plurality of openings provided in the shock mount member is selectively cut out.

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