JPH0617425Y2 - Microphone anti-vibration device - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention is installed between a microphone case and a microphone holder to prevent external vibration from being transmitted to a microphone unit housed in the case. The present invention relates to a microphone anti-vibration device.

[Prior Art] Conventionally, as an anti-vibration device for blocking external vibration transmitted to the microphone unit through the case of the microphone, an elastic sheet such as rubber is wrapped around the microphone unit, and in that state The structure inserted in the case is common.

[Problems to be Solved] The conventional microphone anti-vibration device having such a structure is
Since the elastic body is inserted between the inner wall of the case and the outer surface of the microphone unit and the outer peripheral contact area of the elastic body is the largest, the stress per unit area of the elastic body is small. Therefore, since the compliance that contributes to the vibration absorption is extremely low, there is a problem that the external vibration applied to the case is directly transmitted to the microphone unit without being sufficiently absorbed.

Therefore, an object of the present invention is to solve the problems of the conventional example by using an anti-vibration elastic body interposed between a case and a holder in a state where stress increases.

[Means for Solving the Problems] A microphone anti-vibration device according to the present invention for achieving the above object will be described with reference to FIGS. 1 to 3 showing an embodiment. A case 2 in which the microphone unit 1 is housed and which has a sound wave introducing port 2b on the side surface and a through hole 2a on the rear end surface, and a conical recess 3a which is arranged inside the rear end surface of the case 2 so that the back surface is in contact with the front surface. Central hole
In a state in which the elastic body 3 having the 3b formed therein and the outer diameter smaller than the inner diameter of the case 2 are fitted into the recess 3a of the elastic body 3 and the elastic body 3 is compressed together with the rear end surface of the case 2. Provided on the holder 7, a conical body 4 to be sandwiched, a pulling tool 5 penetrating the through hole 2a, one end of which is fixed to the conical body 4 and the other end of which is coupled to a fulcrum A provided on the holder The microphone vibration isolation device is characterized by including an elastic cord 6 stretched by applying tension between the other fulcrum B and the front end portion of the case 2.

[Operation] In the microphone anti-vibration device having such a configuration, the case 2 is attracted forward by the elastic ropes 6, while the cone 4 fixed to the pulling tool 5 is separated from the case 2. Against this, as a result, the elastic body 3 is compressed by the inner wall of the rear end of the case 2 and the back surface of the conical body 4, and especially the portion where the vicinity of the top of the conical body abuts is greatly deformed and locally localized. Since a large amount of stress is accumulated and the elastic cord 6 is given a tension, a large amount of stress is accumulated in the same manner as the elastic body 3 and the compliance exhibited by both the elastic body 3 and the elastic cord 6 is increased to prevent it. The natural vibration frequency of the vibration system becomes low, and it is possible to absorb and block the vibration noise that enters from the outside through the holder.

Particularly, in the embodiment of FIG. 3, the fulcrum A and the fulcrum B of the holder 7 are
The distance between the fulcrums is changed by adjusting the expansion / contraction portion 8 provided between the elastic body 3 and the elastic cord 6, and the size of the compliance exhibited by the elastic body 3 and the elastic cord 6 is adjusted. It is possible to change the natural vibration frequency of the vibration isolation system.

[Embodiment] Referring to FIGS. 1 and 2, the first embodiment of the present invention will be described in detail. Reference numeral 1 denotes a microphone unit, which in this embodiment has a diameter of 10 mm.
I am using an electret condenser microphone unit.

Reference numeral 2 denotes a case, which is cylindrical and has an inner diameter larger than the outer diameter of the microphone unit 1, a sound wave introducing portion 2b is formed on a side surface, and a through hole 2a is formed at a center of a rear end portion 2c screwed to a side wall portion. ing.

The microphone unit 1 is housed in the cylindrical portion of the case 2.

3 is an elastic body arranged at the inner rear end of the case 2 and is made of foamed resin, and a conical recess 3a is formed on the front surface.
The rear surface contacts the inner rear end of the case 2, and the through hole 2a
A central hole 3b is formed so as to coincide with.

Reference numeral 4 denotes a conical body which is fitted in the recess 3a of the elastic body 3 and holds the elastic body 3 together with the rear end portion 2c of the case 2 and which penetrates the through hole 2a of the case 2 and the central hole 3b of the elastic body 3. Then, one end is fixed to the fulcrum A of the holder 7 by the set screw 7b and is fixed to the pulling tool 5 which is adjustable in clamp position. When the case 2 is pulled forward with respect to the holder 7, the elastic body 3 is compressed. Act as you do.

The elastic cord 6 is a synthetic rubber cord in this embodiment, one end of which is fixed to the front end of the case 2 and the other end of which is stretched by applying tension between the fulcrum B of the holder 7 and the case. The case 2 is held in a state where 2 is pulled forward with respect to the holder 7.

Therefore, the case 2 containing the microphone unit 1
Is supported at its front and rear ends by an elastic body 3 and an elastic cable 6, respectively. The elastic body 3 is in a compressed state, the elastic cable 6 is in an extended state, and both of them have a large internal stress.
The case 2 with the built-in is held apart from the holder 7.

FIG. 3 shows a second embodiment, in which a fulcrum A and a fulcrum B of the holder 7 are provided.
The expansion / contraction part 8 is formed in the portion of the arm 7a provided with.

The structure of the expansion / contraction part 8 is such that the arm 7a is divided into two parts, a forward screw and a reverse screw are formed at each end, and a pipe screw 8a is screwed in, and the pipe screw 8a is rotated to form a fulcrum A and a fulcrum B. It is a structure that changes the interval of.

Further, as the structure of the expansion / contraction part 8, the root part of the arm 7a may have a set screw structure similar to that of the pulling tool 5 shown in FIG. 1 (not shown).

In any case, by changing the distance between the fulcrum A and the fulcrum B, the compression degree and the extension degree of the elastic body 3 and the elastic cord 6 are adjusted to adjust the magnitude of the compliance exhibited by both, and to prevent vibration. It is possible to change the natural vibration frequency of the system.

Further, in the first embodiment, the same effect can be obtained by changing the clamp position of the pulling tool 5.

The microphone anti-vibration device according to the present invention has been described above in detail based on a typical example. In the embodiment of the microphone anti-vibration device according to the present invention, for example, the model of the microphone unit, the elastic body, and the elastic body are used. The shape, material, etc. of the rope are not limited to the structure of the above-mentioned embodiment, and the microphone unit or each elastic body and the shield case and the engagement relationship with the case have the constituent requirements described in the above claims, The present invention can be appropriately modified and carried out as long as it has the effect of the invention and has the effects described below.

[Effect] The microphone anti-vibration device according to the present invention has the following effects.

(1) Large stress is locally accumulated in the elastic body and the elastic rope, the compliance exhibited by both becomes large, and the vibration noise propagating from the holder can be absorbed and completely blocked.

(2) Adjusting the expandable part of the holder to adjust the compression degree and extension degree of the elastic body and elastic cord to adjust the magnitude of the compliance exhibited by these, change the natural vibration frequency of the vibration isolation system, and external vibration Depending on the noise situation, the isolation characteristics of the anti-vibration system can be adjusted to the environment.

(3) Fig. 4 shows the frequency characteristic of the external vibration isolation effect of the embodiment of the present invention.

The holder 7 is attached to the vibration exciter, and the vibration pickup is attached to the position of the microphone unit in the embodiment.
A wideband mechanical vibration was applied and the output voltage of the vibration pickup was recorded (frequency characteristics are indicated by the solid line).

At the same time, a vibration pickup was attached to the vibration exciter, and the output voltage was recorded (frequency characteristics are indicated by a dotted line), and both were compared.

The characteristic shown by the solid line shows the blocking effect because the level is lowered in almost the entire band compared to the characteristic of the dotted line, and the configuration of the present invention is remarkably excellent as a microphone vibration isolator. It is clear.

With the above advantages, it is possible to perform a high S / N measurement with a simple structure that is not affected by external vibration.

[Brief description of drawings]

FIG. 1 is an axial sectional view of a first embodiment of the present invention, FIG. 2 is an exploded perspective view of an essential part of the same, FIG. 3 is an axial sectional view of an essential part of the second embodiment, and FIG. 4 is a first embodiment. It is a frequency characteristic figure which shows the image stabilizing effect of an example. 1 is a microphone unit, 2 is a case, 3 is an elastic body,
Reference numeral 4 is a cone, 5 is a pulling tool, and 6 is an elastic cord.

Claims (3)

[Scope of utility model registration request] 1. A case (2) having a microphone unit (1) housed therein, a sound wave introducing port (2b) on a side surface and a through hole (2a) on a rear end surface, and a rear end surface of the case (2). Conical recess located inside back to back and front
An elastic body (3) having (3a) and a central hole (3b),
The outer shape is smaller than the inner diameter of the case (2) and the elastic body (3)
(4) which is fitted in the concave portion (3a) of the case and holds the elastic body (3) together with the rear end surface of the case (2) in a compressed state.
And a pulling tool (5) which penetrates through the through hole (2a) and has one end fixed to the conical body (4) and the other end coupled to a fulcrum A provided on a holder (7), A microphone anti-vibration device comprising an elastic cord (6) stretched by applying tension between another fulcrum B provided on the holder (7) and the front end of the case 2. 2. A utility model registration claim 1 characterized in that an extension / contraction part (8) for changing the distance between the fulcrum A and the fulcrum B of the holder (7) is provided. Microphone anti-vibration device. 3. A microphone antivibration device according to claim 1, wherein the pulling tool (5) is connected at a fulcrum A so that the clamp position can be adjusted.