JP4659704B2 - Condenser microphone unit and manufacturing method thereof - Google Patents

Description

  The present invention relates to a condenser microphone unit and a method for manufacturing the same, and more particularly to a technique for applying stress to an acoustoelectric transducer that is a built-in component of a unit case during assembly.

  The condenser microphone unit is assembled by housing an acoustoelectric converter in which the diaphragm stretched on the support ring and the fixed pole supported on the insulating pedestal are arranged facing each other through a spacer in the unit case. It is done.

  At the time of this assembly, the acoustoelectric transducer as a built-in component is fixed by applying an appropriate stress so that it does not rattle in the unit case during use. Conventionally, for this fixing method, for example, as described in Patent Document 1, a unit case is plastically deformed in a caulking process, and for example, as described in Patent Document 2, a screw is used. The fixing method is known.

Japanese Patent Laying-Open No. 2005-354574 (FIG. 4) JP 2005-184347 A

  The former fixing method by caulking is usually applied to a condenser microphone unit with relatively low performance and low cost, but it is relatively difficult to adjust the stress, especially in a unidirectional unit with a low diaphragm tension. Uneven internal stress is applied to the support ring of the diaphragm, which may cause wrinkles on the diaphragm.

  On the other hand, according to the method of fixing using the latter screw, the stress can be adjusted relatively easily by the tightening condition of the screw, so that uneven internal stress is applied to the support ring of the diaphragm. There is almost no.

  For this reason, the unit is assembled in a state where the tension of the diaphragm is lowered, so that it is applied to an expensive unit with relatively high performance. However, since the unit case or the like needs to be threaded, there is a problem that an increase in cost is inevitable.

  Accordingly, an object of the present invention is to fix an acoustoelectric transducer by applying appropriate stress in a unit case without using caulking or screws.

  In order to solve the above-described problems, according to the present invention, as described in claim 1, the diaphragm stretched on the support ring and the fixed pole supported by the insulating base are arranged to face each other via a spacer. In the condenser microphone unit in which the acoustoelectric transducer configured as described above is housed in a unit case, the unit case and the insulating base are connected via a solvent evaporation volume reducing type adhesive whose volume is reduced by evaporation of the solvent. It is characterized by being fixed.

  According to a preferred aspect of the present invention, as described in claim 2, the unit case has a locking piece for the support ring at one end and the other end extends toward the insulating pedestal side. A ring-shaped case having an L-shaped cross section for pressing the support ring toward the insulating pedestal side is used, and the other end of the ring-shaped case and the insulating pedestal are fixed via the solvent evaporation volume reducing adhesive.

  According to a third aspect of the present invention, in the acoustoelectric converter, the fixed pole is supported on each of both sides of the insulating base, and is stretched on the support ring with respect to the fixed pole. A diaphragm is a variable directivity acoustoelectric converter in which the diaphragms are arranged to face each other via the spacer, and each of the support rings is fixed to the insulating base by the ring-shaped case.

  Further, the present invention includes the invention of the manufacturing method according to claim 4. That is, in the invention according to claim 4, an acoustoelectric converter configured by disposing a diaphragm stretched on a support ring and a fixed pole supported by an insulating pedestal through a spacer is provided. In the method of manufacturing a condenser microphone unit housed in a unit case, as the unit case, a locking piece for the support ring is provided at one end and the other end extends toward the insulating pedestal side, and the support ring is After applying a ring-shaped case with an L-shaped cross section that is pressed down to the insulating pedestal side, and applying a solvent evaporation volume reducing type adhesive that reduces the volume by evaporation of the solvent between the other end of the ring case and the insulating pedestal The solvent is evaporated to reduce the volume of the adhesive, and a predetermined stress is applied to the acoustoelectric transducer.

  According to the present invention, since the adhesive for fixing the unit case and the insulating base is a solvent evaporation volume reduction type in which the volume is reduced by evaporation of the solvent, when the volume is reduced as the adhesive is cured. A predetermined stress can be applied to the acoustoelectric transducer, which is a built-in component in the unit case, by the generated contractive force.

  Therefore, screw processing is unnecessary, and the cost can be reduced accordingly. In addition, since the shrinkage force can be controlled by the amount of the organic solvent added to the adhesive and the gap between the bonded portions, a desired stress can be applied to the acoustoelectric transducer that is a built-in component.

  Next, an embodiment of the present invention will be described with reference to FIGS. 1 to 3, but the present invention is not limited to this. FIG. 1 is an exploded sectional view showing a condenser microphone unit according to an embodiment of the present invention, and FIGS. 2 and 3 are sectional views showing an assembled state thereof.

  As shown in FIG. 1, the condenser microphone unit 10 according to this embodiment has variable directivity in which a first capacitor element 10a and a second capacitor element 10b as acoustoelectric converters are arranged on both sides of an insulating base 20. Although it is a condenser microphone unit, it may be a unidirectional condenser microphone unit in which one of the capacitor elements is omitted.

  Since the first capacitor element 10a and the second capacitor element 10b have the same configuration, the first capacitor element 10a will be mainly described, and the reference numerals of the components of the second capacitor element 10b are shown in parentheses.

  Capacitor element 10a (10b) electrically connects diaphragm 11a (11b) stretched with a predetermined tension on support ring 12a (12b) and fixed pole 14a (14b) supported on insulating base 20. The spacer ring 13a (13b) is disposed so as to face each other.

  The support ring 12a (12b) is made of metal, and an electrode terminal 15a (15b) for taking out an electric signal is arranged on the outer surface side thereof. Although not shown, the fixed pole 14a (14b) has a large number of sound holes.

  The insulating pedestal 20 is made of a synthetic resin disc body having an air chamber 22 having a predetermined volume in the central portion, and acoustic resistance materials 21 and 21 made of, for example, nylon mesh are provided in the hole 22. A fixing projection 23 is formed on the outer peripheral surface of the insulating base 20. The insulating pedestal 20 supports the fixed pole 14a on one side and the fixed pole 14b on the other side.

  In this embodiment, a ring-shaped case 16a (16b) is used as a unit case, and the capacitor element 10a (10b) is fixed to the insulating base 20 via the ring-shaped case 16a (16b).

  The ring-shaped case 16a (16b) is an L-shaped ring having a locking piece 161 for the support ring 12a (12b) at one end, and the other end 162 is extended toward the protrusion 23 side of the insulating base 20. Yes.

  To assemble the condenser microphone unit 10, the electrode element 15a (15b) is disposed on the outer surface side of the support ring 12a (12b), and the capacitor element 10a is formed by the ring-shaped case 16a (16b) as shown in FIG. Lightly press (10b) against the insulating base 20.

  In this state, the adhesive 30 is applied between the other end 162 of the ring-shaped case 16a (16b) and the protrusion 23 of the insulating base 20. In the present invention, a solvent evaporation volume reducing type adhesive whose volume is reduced by evaporation of the solvent is used for the adhesive 30.

  This type of adhesive is commercially available, for example, No. No. No. manufactured by Nogawa Chemical Co., Ltd. 1663G (chloroprene rubber type). For the application of the adhesive, it is preferable to use a spin coater in order to produce a stable and high-performance unit.

  After application of the adhesive 30, the solvent is evaporated and cured. Since the volume of the adhesive 30 contracts during this curing, the ring-shaped case 16a (16b) is pulled toward the insulating base 20 as shown in FIG. 3, and the capacitor element 10a (10b) is fixed by the stress. .

  Thus, according to the present invention, the capacitor element 10a (10b) can be fixed to the insulating base 20 solely by the contraction force of the adhesive 30 without using caulking or screws.

  Further, the shrinkage force of the adhesive 30 can be appropriately adjusted according to the amount of the organic solvent applied to the adhesive 30 and the distance between the other end 162 of the ring-shaped case 16a (16b) and the protrusion 23 of the insulating base 20. it can.

1 is an exploded cross-sectional view showing a condenser microphone unit according to an embodiment of the present invention. Sectional drawing which shows the assembly state of the said capacitor | condenser microphone unit. Sectional drawing which shows the assembly state of the said capacitor | condenser microphone unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Capacitor microphone unit 10a, 10b Capacitor element 11a, 11b Diaphragm 12a, 12b Support ring 13a, 13b Spacer ring 14a, 14b Fixed pole 15a, 15b Electrode terminal 16a, 16b Ring-shaped case 161 Locking piece 20 Insulation base 21 Acoustic resistance Material 22 Air chamber 23 Projection 30 Adhesive

Claims (4)

In a condenser microphone unit in which an acoustoelectric converter is configured in which a diaphragm stretched on a support ring and a fixed pole supported on an insulating base are arranged to face each other with a spacer interposed therebetween in a unit case. ,
The condenser microphone unit, wherein the unit case and the insulating pedestal are fixed via a solvent evaporation volume reducing type adhesive whose volume is reduced by evaporation of the solvent.   As the unit case, a ring-shaped case having an L-shaped cross section that has a locking piece for the support ring at one end and extends the other end toward the insulating pedestal side and presses the supporting ring toward the insulating pedestal side is used. 2. The condenser microphone unit according to claim 1, wherein the other end of the ring-shaped case and the insulating pedestal are fixed via the solvent evaporation volume reducing type adhesive.   The acoustoelectric converter is configured such that the fixed poles are supported on both sides of the insulating pedestal, and diaphragms stretched on the support ring with respect to the fixed poles are arranged to face each other via the spacers. 3. The condenser microphone unit according to claim 2, wherein each of the support rings is fixed to the insulating base by the ring-shaped case. A condenser microphone unit comprising an acoustoelectric transducer housed in a unit case in which a diaphragm stretched on a support ring and a fixed pole supported on an insulating pedestal are arranged oppositely via a spacer. In the manufacturing method,
As the unit case, a ring-shaped case with an L-shaped cross section that has a locking piece for the support ring at one end and the other end extends toward the insulating pedestal side and presses the supporting ring toward the insulating pedestal side, After applying a solvent evaporation volume reduction type adhesive whose volume is reduced by evaporation of the solvent between the other end of the ring-shaped case and the insulating base, the solvent is evaporated to reduce the volume of the adhesive. A method of manufacturing a condenser microphone unit, wherein a predetermined stress is applied to the acoustoelectric transducer.

Images