JP4374292B2 - Unidirectional dynamic microphone - Google Patents

Description

  The present invention relates to a unidirectional dynamic microphone, and more particularly to a configuration of an air chamber in a grip housing included as part of an acoustic circuit of a dynamic microphone unit.

  As described in Patent Document 1, an air chamber is one of the factors that determine the frequency characteristics of a unidirectional dynamic (dynamic) microphone. In a handheld microphone for vocals or the like, the air chamber is usually provided in a grip housing formed in a cylindrical shape. One example will be described with reference to FIG.

  The hand-held unidirectional dynamic microphone includes a grip housing 10 made of, for example, die cast and formed in a cylindrical shape, and the microphone unit 20 is supported on the tip side thereof. Although not shown, the microphone unit 20 includes a diaphragm with a voice coil attached thereto and a magnetism generating circuit having a magnetic gap, and the voice coil is arranged in the magnetic gap so as to vibrate via the diaphragm. Has been.

  Since it is unidirectional, the microphone unit 20 includes a front acoustic terminal 20a and a rear acoustic terminal 20b. The microphone unit 20 is attached to the front end side of the grip housing 10 via the connection ring 11 with its rear end side being airtightly inserted into the connection ring 11. In this case, the connection ring 11 is used to reduce handling noise. A shock mount member 12 exhibiting rubber elasticity is interposed between the grip housing 10 and the grip housing 10. Reference numeral 13 denotes a pressing ring.

  A connector housing portion 14 is integrally formed on the rear end side of the grip housing 10, and an output connector 30 is mounted in the connector housing portion 14. The microphone unit 20 and the output connector 30 are connected by a lead wire (not shown). The inside of the grip housing 10 is hollow and acts as an air chamber 10a of the microphone unit 20.

  In order to improve the sound quality in the low frequency range, it is preferable that the volume of the air chamber 10a is large. In any case, in order to obtain good directivity, it is necessary to prevent air from entering the air chamber 10a from the outside. . Therefore, conventionally, after connecting the microphone unit 20 and the output connector 30 with lead wires (not shown), the output connector 30 side is sealed in the grip housing 10 with a sealing material 15 such as silicon sealant. Yes.

JP-A-5-49090

  However, the above conventional example has the following problems. First, when an external force such as hitting or rubbing is applied to the grip housing 10, the housing is slightly displaced, and the volume of the internal air chamber 10 a is also changed, but this is also changed. It appears.

  In addition, handheld microphones often fall from a table or a microphone stand. In particular, in a microphone with a cable, a strong impact is applied to the microphone unit 20 because it falls from the head case side to the floor surface, which may cause the microphone unit to drop off, disconnection of the voice coil, damage to the output connector, and the like.

  Next, in terms of work, not only is it difficult to inject the sealing material 15 for sealing the air chamber 10a, but a waiting time until curing is required, and productivity is poor. Further, when the output connector 30 is damaged and replaced due to, for example, a drop impact, the sealing material 15 must be scraped off and removed, which is very troublesome.

  Therefore, an object of the present invention is to reduce handling noise due to an external force applied to the grip housing and to be robust against a drop impact in a unidirectional dynamic microphone having a microphone unit air chamber in the grip housing. In addition, it is to facilitate assembly and disassembly.

  In order to solve the above-mentioned problems, an invention according to claim 1 of the present application includes a grip housing formed in a cylindrical shape, supports a microphone unit at a front end side of the grip housing, and the microphone unit at a rear end side thereof. In the unidirectional dynamic microphone, in which an output connector connected through a lead wire is mounted and an air chamber included as part of the acoustic circuit of the microphone unit is provided in the grip housing. Is formed as a cavity as the air chamber, and is fitted to a cylindrical cavity sleeve in which the rear end portion of the microphone unit is fitted in the front end opening, and to the outer peripheral surfaces on the front end side and the rear end side of the cavity sleeve. The front sleeve is made of a cylindrical body of a rubber elastic material that coaxially supports the cavity sleeve in the grip housing. A mounting member and a rear shock mount member, and at least one engagement hole is formed in a shock mount mounting portion of the cavity sleeve to which the front shock mount member is mounted, A fixing screw extending to the inside of the engagement hole via a front shock mount member is provided.

  In the invention according to claim 2 of the present application, the front shock mount member is fitted into the inner surface of the front shock mount member so that the front end of the fixing screw is fitted into the engagement hole. A boss having a hole is integrally formed.

  The invention according to claim 3 of the present application is characterized in that an airtight connector support cover for the output connector is integrally formed on the rear shock mount member.

  According to the first aspect of the present invention, since the air chamber is provided in the cavity sleeve supported in the grip housing via the front and rear shock mount members, external force such as tapping and rubbing is applied to the grip housing. Even if is added, the volume of the air chamber does not change. Therefore, handling noise is reduced.

  In addition, since the fixing screw has entered even into the engagement hole formed in the cavity sleeve, the axial movement of the cavity sleeve, especially when dropping from the head case side, is prevented, preventing the microphone unit from falling off. Is done. Furthermore, since the performance can be measured before the cavity sleeve is incorporated into the grip housing, that is, in the sub-assembly state, defects in the final assembly can be reduced.

  According to the second aspect of the present invention, since the fixing screw enters the engagement hole via the boss of the front shock mount member, the impact upon dropping to the microphone unit or the like is more effectively mitigated. Further, according to the third aspect of the invention, since a sealing material such as silicon sealant is not required, not only assembly / disassembly work can be easily performed, but also the shock mount member can be used as a connector support cover. The number of parts can be reduced.

  Next, an embodiment of the present invention will be described with reference to FIGS. 1 to 4, but the present invention is not limited to this. FIG. 1 is a sectional view showing a unidirectional dynamic microphone according to the present invention, and FIGS. 2 to 4 are exploded sectional views showing an assembling procedure thereof.

  First, referring to FIG. 1, a unidirectional dynamic microphone according to the present invention includes a grip casing 100, a cavity sleeve 200, a microphone unit 20, and an output connector 30 as a basic configuration. The microphone unit 20 and the output connector 30 may be the same as those used in the conventional example described with reference to FIG.

  That is, since the microphone unit 20 is unidirectional, the microphone unit 20 includes a front acoustic terminal 20a and a rear acoustic terminal 20b. Although not shown, the microphone unit 20 is a dynamic type (electrodynamic type). A diaphragm and a magnetism generating circuit having a magnetic gap are included, and a voice coil is arranged in the magnetic gap so as to vibrate via the diaphragm.

  The output connector 30 is a connector defined by EIAJ RC-5236 “Latch lock type circular connector for acoustic equipment”, that is, a cylindrical base 31 made of an electrical insulator and a first pin for grounding (not shown in the drawing) ), A 3-pin type connector in which three pins, the second pin 32 used as the hot side of the signal and the third pin 33 used as the cold side of the signal, are provided.

  In addition to the three pins, this connector is provided with a male screw 34 that can be projected and retracted in the radial direction of the base 31 and a grounding terminal plate 35 having a female screw hole. It is electrically connected to the first pin for grounding by a connection fitting or the like (not shown).

  Next, the structure of each member will be described according to the assembly procedure with reference to FIGS. First, referring to FIG. 2, the microphone unit 20 and the output connector 30 are attached to the cavity sleeve 200. The cavity sleeve 200 is preferably made of die-cast and formed into a cylindrical shape, and the inside of the cavity is used as an air chamber 201 included as a part of the acoustic circuit of the microphone unit 20. The cavity sleeve 200 may be made of synthetic resin.

  The microphone unit 20 is supported by the cavity sleeve 200 by inserting the rear end portion 20 c thereof into the front end opening 202 of the cavity sleeve 200. In addition, a front shock mount member 210 made of a cylindrical body (annular body) of rubber elastic material is fitted on the outer peripheral surface on the distal end side of the cavity sleeve 200. A flange 202 for positioning the front shock mount member 210 is formed on the outer peripheral surface of the cavity sleeve 200.

  The width and thickness of the front shock mount member 210 may be arbitrarily designed, but a boss 211 is integrally formed on the inner surface side of the front shock mount member 210 toward the center thereof. Correspondingly, the cavity sleeve 200 has an engagement hole 204 into which the boss 211 is fitted.

  The boss 211 and the engagement hole 204 are preferably provided at a plurality of positions with a predetermined interval, but may be one each. In this example, the boss 211 is formed with a fitting hole 212 into which a distal end portion of a fixing screw 102 described later is fitted.

  A rear shock mount member 230 made of a rubber elastic material is attached to the rear end side of the cavity sleeve 200. The rear shock mount member 230 is integrally formed with a skirt portion 231 that covers the outer peripheral surface of the cavity sleeve 200 and an airtight connector support cover 232 for the output connector 30. A skirt portion 231 is disposed between the cavity sleeve 200 and the grip housing 100 and acts as a substantial shock mount.

  The connector support cover 232 is inserted with a grounding first pin (not shown) provided on the output connector 30, hot and cold second and third signal pins 32 and 33, and a grounding terminal plate 35. A pin insertion hole 233 and a terminal plate insertion hole 234 are formed. Note that only one pin insertion hole 233 is shown for convenience of drawing, but there are actually three.

  In this case, in order to prevent air from entering the air chamber 201 from the rear end side of the cavity sleeve 200, the pin insertion holes 233 and the terminal plate insertion holes 234 are formed to be small, and the first pin described above is formed in these holes. (The illustration is omitted) By forcibly pushing the second and third pins 32 and 33 and the grounding terminal plate 35 into an airtight fit, a sealing material such as a silicon sealant can be made unnecessary.

  In an actual assembly operation, the microphone unit 20 and the output connector 30 are connected in advance with a lead wire (not shown) that passes through the cavity sleeve 200, and then the microphone unit 20 and the output connector 30 are connected to the cavity as described above. Attached to the sleeve 200, the subassembly 200A shown in FIG.

  In the state of the subassembly 200A, the air chamber 201 in the cavity sleeve 200 is almost sealed, so that the performance as a unidirectional dynamic microphone can be measured at this stage. Therefore, defective products can be repaired or eliminated before reaching the final assembly.

  After measuring the performance, the subassembly 200A is inserted into the grip housing 100 and screwed. In order to perform this screwing, the grip housing 100 is provided with female screw holes 101 at several positions facing the front shock mount member 210, and fixing screws 102 are provided in the female screw holes 101 as shown in FIG. The subassembly 200A is fixed in the grip housing 100 by screwing.

  In this case, in order to prevent the cavity sleeve 200 from moving in the axial direction, a male screw having a length that allows the tip of the fixing screw 102 to reach the engagement hole 204 of the cavity sleeve 200 is used.

  In this example, since the fixing screw 102 enters the engagement hole 204 in a state of being fitted in the fitting hole 212 of the boss 211, the front shock mount member 210 is not only in the radial direction of the cavity sleeve 200 but also in the axial direction. Also exerts a shock mount effect.

  The grip housing 100 is a cylindrical body that is slightly larger than the subassembly 200A, and is integrally provided with a connector housing portion 110 on the rear end side. The grip casing 100 is preferably made of die-cast and has conductivity.

  A through hole 111 is formed in the connector housing portion 110 at a position facing the male screw 34 of the output connector 30. A screwdriver (not shown) is inserted through the through hole 111 and the male screw 34 is rotated to protrude from the base 31. Thus, the grip housing 100 and the ground terminal plate 35 are electrically connected by being brought into contact with the inner surface of the connector housing portion 110.

  Thereafter, a sleeve-like tail cover 120 made of a rubber material is put on the outer periphery of the connector housing 110, and a mesh for protecting the microphone unit 20 after the name ring 130 is fitted on the front end side of the grip housing 100, for example. A metal head case 140 is covered.

  Thus, the unidirectional dynamic microphone shown in FIG. 1 is finally assembled. In the present invention, the subassembly 200A includes the front shock mount member 210 and the rear shock mount member 230 in the grip housing 100. And is supported coaxially.

  Therefore, even if an external force such as hitting or rubbing is applied to the grip housing 100, the external force is attenuated by the shock mount members 210 and 230, and the volume of the air chamber 201 in the cavity sleeve 200 changes. Therefore, handling noise is greatly reduced.

  Further, although the shock mount members 210 and 230 effectively act against a drop impact, according to the present invention, since the fixing screw 102 enters the engagement hole 204 as described above, the microphone is connected to the head. When falling from the case 140 side, the axial displacement or movement of the cavity sleeve 200 is stopped within a very limited range, thereby protecting the microphone unit 20 and the output connector 30.

  Even if the output connector 30 is damaged due to a drop impact or the like, it is easily disassembled because there is no sealing material such as a silicon sealant for sealing the air chamber as in the conventional example described in FIG. Can be repaired. That is, when repairing, it is only necessary to remove the output connector 30 from the rear shock mount member 230.

  In the above-described embodiment, the front shock mount member 210 is formed with the boss 211 that fits into the engagement hole 204 of the cavity sleeve 200, and the fitting hole 212 into which the fixing screw 102 is fitted into the boss 211. In this case, a cushion effect by the boss 211 is provided between the fixing screw 102 and the engaging hole 204. However, in some cases, the fixing screw 102 is used as a mere opening and the fixing screw 102 is used as the engaging hole 204. Such a mode may also be included in the present invention.

Sectional drawing which shows an example of the unidirectional dynamic microphone by this invention. FIG. 3 is an exploded cross-sectional view illustrating each member of the microphone according to an assembly order. FIG. 3 is an exploded cross-sectional view illustrating each member of the microphone according to an assembly order. FIG. 3 is an exploded cross-sectional view illustrating each member of the microphone according to an assembly order. Sectional drawing which shows the internal structure of the conventional unidirectional dynamic microphone.

Explanation of symbols

20 Microphone unit 30 Output connector 100 Grip housing 102 Fixing screw 110 Connector housing part 200 Cavity sleeve 204 Engagement hole 200A Subassembly 201 Air chamber 210 Front shock mount member 211 Boss 212 Fitting hole 230 Rear shock mount member 231 Skirt part

Claims (3)

A grip housing formed in a cylindrical shape is supported, and a microphone unit is supported on the front end side of the grip housing, and an output connector connected to the microphone unit via a lead wire is mounted on the rear end side, In the unidirectional dynamic microphone provided with an air chamber included as part of the acoustic circuit of the microphone unit in the grip housing,
The inside is a cavity as the air chamber, and a cylindrical cavity sleeve in which the rear end portion of the microphone unit is fitted in the front end opening, and the outer peripheral surfaces on the front end side and the rear end side of the cavity sleeve A front shock mount member and a rear shock mount member that are fitted and are formed of a cylindrical body of a rubber elastic material that coaxially supports the cavity sleeve in the grip housing;
At least one engagement hole is formed in a shock mount mounting portion of the cavity sleeve to which the front shock mount member is mounted, and the engagement hole is formed on the grip housing side via the front shock mount member. A unidirectional dynamic microphone characterized in that a fixing screw extending inward is provided.   On the inner surface side of the front shock mount member, there is integrally formed a boss having a fitting hole that fits into the engagement hole and into which the tip of the fixing screw is fitted. The unidirectional dynamic microphone according to claim 1.   The unidirectional dynamic microphone according to claim 1 or 2, wherein an airtight connector support cover for the output connector is integrally formed on the rear shock mount member.

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