JP4892277B2 - Flexible shaft fixing structure and fixing method, and condenser microphone device - Google Patents

Description

  The present invention relates to a flexible flexible shaft fixing structure composed of at least two wires wound spirally, and more specifically, the flexible shaft is easily and reliably fixed without using an adhesive or the like. The present invention relates to a fixing structure, a fixing method thereof, and a condenser microphone device having the fixing structure.

  A flexible shaft is a bendable rod-shaped body composed of at least two wires, and the outer winding is further spirally wound along the outer peripheral surface of the spirally wound inner winding. Thus, it can be held in a state bent in an arbitrary direction by the correlation between the frictional resistance and the elastic restoring force between the inner winding and the outer winding.

  Utilizing such bending characteristics, in the field of microphones, flexible shafts are used in bent portions of gooseneck type microphones. When using a flexible shaft, it cuts out to a desired dimension from a long flexible shaft as a mother, but as an end treatment at that time, for example, in the invention described in Patent Document 1, the end of the flexible shaft is made of resin. A flexible shaft is attached to the microphone holder via the cap.

  In addition to this, the end of the flexible shaft is fixed to the microphone holder with an adhesive without performing end processing. In addition, a soldering method or the like is known as a method for coupling the flexible shaft and the microphone holder.

  However, the above method has the following problems. That is, in the gooseneck type microphone, in order to prevent noise generation due to external electromagnetic waves, it is necessary to electrically connect the flexible shaft and the microphone holder as ground (ground). However, when a resin cap or adhesive as described above is used, it is necessary to secure electrical conduction after fixing the flexible shaft and the microphone holder.

  If soldering is employed for fixing the flexible shaft and the microphone holder, fixing and electrical conduction can be achieved at the same time, but this has the following problems. That is, according to soldering, the flexible shaft is heated, and depending on the heating temperature, the spring characteristics of the coil may change, so it is necessary to strictly control the temperature during heating. In particular, recently used lead-free solder has a higher melting temperature than ordinary lead solder, and requires stricter temperature control.

JP 2001-32816 A

Therefore, issues of the present invention, the fixed structure of the flexible shaft that can be easily and reliably fixed while ensuring electrical conduction and a support member such as a flexible shaft and a microphone holder and its fixing method and its fixing structure An object of the present invention is to provide a condenser microphone device provided with

In order to solve the above-described problems, the present invention has several features described below. First, the invention described in claim 1 includes an inner winding wound spirally and an outer winding wound spirally so as to enter between the inner windings on the outer peripheral surface side of the inner winding. and a winding, a flexible shaft consisting of at least two metal wires, in fixing structure of the flexible shaft is fixed to cylindrical support in member made of a metal material, it is inserted along the inner circumferential surface of the flexible shaft And having a cylindrical insert fitting made of a plastically deformable material, expanding the diameter of the insert fitting from the inside, and crimping and fixing the flexible shaft to the inner surface of the support member while ensuring electrical continuity. It is characterized by.

The present invention also includes a method for fixing the flexible shaft. In other words, the invention according to claim 2 is characterized in that the inner winding wound spirally and the outer winding wound spirally so as to enter between the inner windings on the outer peripheral surface side of the inner winding. and a winding, a flexible shaft consisting of at least two metal wires, in a fixing method of the flexible shaft is fixed to cylindrical support in member made of a metal material, 塑 resistance along the inner circumferential surface of the flexible shaft insert the tubular insert fittings made of deformable material, by moving toward the other end from one end of the upper Symbol insert fitting the enlarged diameter section whose diameter increases the insert fitting from inside, the inside of the insert fitting diametrically enlarged from, and characterized in that crimped while ensuring electrical conduction to the inner surface of the upper Symbol support the flexible shaft.

According to a third aspect of the present invention, in the second aspect of the invention, the insert fitting includes a cylindrical insertion portion that is inserted along the inner peripheral surface of the flexible shaft, and the insertion portion on one end side of the insertion portion. and a flange portion formed larger than the outer diameter of the said support member, is characterized in that the stopper to receive the flange portion of the insert fitting is provided.

According to a fourth aspect of the present invention, in the second or third aspect, the diameter expanding means has a guide rod having an outer diameter smaller than the inner diameter of the insert fitting, and an outer diameter larger than the inner diameter of the insert fitting. It includes integrally a enlarged head having, by pulling toward the other end the guide rods from the one end of the insert fitting, wherein said enlarged head is enlarged to the insert fitting from inside It is said.

The present invention also includes a condenser microphone device having the flexible shaft fixing structure. In other words, the invention according to claim 5 is characterized in that the inner winding wound spirally and the outer winding wound spirally so as to enter between the inner windings on the outer peripheral surface side of the inner winding. From a strut including a flexible flexible shaft made of at least two metal wires of winding, a condenser microphone unit attached to the tip of the strut, and a metal material connected to the flexible shaft at the other end of the strut in the condenser microphone apparatus comprising a cylindrical support member made, having a tubular insert fittings made of plastically deformable material that is inserted along the inner circumferential surface of the flexible shaft, the support member the flexible shaft for crimped while ensuring electrical conduction to the inner surface, the insert fitting is expanded from the inside by a predetermined enlarged diameter section It is characterized by a door.

  According to the first and second aspects of the invention, the insert metal fitting is inserted inside the flexible shaft, and the insert metal fitting is enlarged by a predetermined diameter expanding means, thereby ensuring electrical continuity and simplifying. And a flexible shaft can be reliably crimped | bonded to a support member (microphone holder).

  According to the invention described in claim 3, a large-diameter flange portion is provided at one end of the cylindrical insertion portion, and a stopper for receiving the flange portion of the insert metal fitting is provided on the support member. By simply inserting the insert metal fitting, the insert metal fitting is received by the stopper, so that it can be easily attached and can be crimped with the flexible shaft fixed to the support member.

  According to the invention described in claim 4, by expanding the diameter of the insert metal fitting using the diameter expansion means, the insert metal fitting can be easily and reliably expanded from the inside without requiring a complicated mechanism. The flexible shaft can be fixed.

  According to the fifth aspect of the present invention, since the flexible shaft of the gooseneck condenser microphone can be easily attached to the microphone holder and at the same time, electrical conduction can be obtained, a condenser microphone free from noise generation due to external electromagnetic waves can be obtained. .

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view of a condenser microphone device according to an embodiment of the present invention, and FIG. 2 is a partially enlarged cross-sectional view of the condenser microphone device having a flexible shaft fixing structure. In this embodiment, the fixing structure of the flexible shaft is illustrated as applied to a microphone.

  As shown in FIG. 1, the condenser microphone device M includes a column P using a flexible shaft 1, and a capacitor microphone unit MU connected to a microphone driving unit (not shown) is attached to the tip of the column P. . In the present invention, the configuration of the condenser microphone unit MU is an arbitrary matter, and thus the description thereof is omitted.

  A microphone holder 2 for installing the microphone device M on the installation surface B such as a table is integrally attached to the other end side of the column P. In this example, the microphone holder 2 is directly attached to the installation surface B via a lock nut (not shown), but other attachment means may be used.

  In this example, the entire support P is composed of the flexible shaft 1, but in addition to this, an elastic pipe or the like may be used in part, and the flexible shaft 1 is fixed to the microphone holder 2, and these are electrically connected. If it has a shield structure that is electrically connected, it can be changed arbitrarily according to the specifications.

  As shown in FIG. 2, the flexible shaft 1 has a flexible shaft 1 cut out to a predetermined length and a microphone holder 2 as a support member, which are crimped and fixed via an insert fitting 3.

  The flexible shaft 1 includes an inner winding 11 spirally wound at a predetermined pitch and an outer winding spirally wound along the outer peripheral surface so as to block the pitch between the inner windings 11. 12 and is formed into a hollow pipe shape.

  The inner winding 11 is a coil spring made of a steel metal wire having a round cross section and bearing an elastic restoring force. On the other hand, the outer winding 12 is made of, for example, a copper coil having a triangular cross section, and is made of a material that is difficult to work and harden due to plastic deformation.

  The inner winding 11 and the outer winding 12 are preferably coated on the surface with a synthetic resin in order to improve the appearance while preventing fingers from being sandwiched between the coils. The length and diameter of the flexible shaft 1 are arbitrarily selected according to specifications.

  The microphone holder 2 is made of a molded product such as an aluminum alloy and is formed in a cylindrical shape. A shaft support hole 21 into which the end of the flexible shaft 1 is inserted is formed at the center of the microphone holder 2.

  The shaft support hole 21 has a slightly larger diameter than the outer diameter of the flexible shaft 1, and a locking portion 22 that receives the end portion 13 of the flexible shaft 1 is formed at the bottom. The locking portion 22 is provided so as to protrude from the inside of the shaft support hole 21 toward the center, and in order to draw out a microphone cable (not shown) connected to the microphone unit MU through the flexible shaft 1 at the center. A lead-out hole 23 is formed.

  On the lower end side of the microphone holder 22, a mount portion 24 for attaching to the attached portion B (FIG. 1) is provided. The mount portion 24 is formed with a thread on the outer peripheral side, and the inside communicates with the shaft support hole 21 via a lead-out hole 23 for drawing a cable (not shown) from the condenser microphone unit MU to the outside. ing.

In fixing the flexible shaft 1 and the microphone holder 2, the insert metal fitting 3 is used in the present invention, and the insert metal fitting 3 preferably used is shown in FIG. The insert fitting 3 is made of a plastically deformable molded product such as an aluminum alloy, for example, and includes an insertion portion 31 inserted into the flexible shaft 1. Inserting portion 31 inside a hollow pipe, it is formed on the same or slightly smaller diameter crucible ho and the inner diameter of the flexible shaft 1.

A stopper 32 that comes into contact with the end portion of the flexible shaft 1 is integrally provided at the end portion (lower end in FIG. 3) of the insertion portion 31. Stopper 32 is formed in a flange shape radially from the end portion of the insertion portion 31, the outer periphery thereof are formed on the same or slightly smaller diameter crucible ho to the outer diameter of the flexible shaft 1.

  Next, with reference to FIGS. 4A to 4C, prior to describing an example of the fixing procedure of the flexible shaft 1, the mounting structure for the flexible shaft 1 of the present invention has a dedicated fixture (diameter expanding means). ) Is used.

  As shown in FIG. 4 (a), the fixture 4 is made of a strong metal rod-like body such as a steel material, and the guide rod 41 inserted along the inner peripheral surface 33 of the insert fitting 3, and the guide rod 41. Is integrally provided with an enlarged diameter head 42 integrally formed on one end side (the upper end side in FIG. 4A).

The guide rod 41 has an outer diameter smaller than the inner diameter of the inner peripheral surface 33 of the insert fitting 3 , and a driving means (not shown) such as an actuator is connected to the other end side (the lower end in FIG. 4A). Is done. In addition, the length of the fixture 4 can be arbitrarily selected according to the specification.

  The diameter-expanding head 42 has an outer diameter that is smaller than the inner diameter of the flexible shaft 1 and larger than the inner diameter of the inner peripheral surface 33 of the insert fitting 3, and gradually increases from the root of the guide rod 41 toward the tip side. It is preferable that a tapered surface 43 having a large diameter is formed.

In order to attach the flexible shaft 1 to the microphone holder 2 using the fixture 4 , first, after inserting the lower end of the guide rod 41 from the upper end opening of the insertion portion 31 of the insert fitting 3, the microphone 4 The stopper 32 is inserted into the shaft support hole 21 so that the stopper 32 faces downward.

  As a result, the insert fitting 3 inserted into the shaft support hole 21 is stopped by the stopper 32 coming into contact with the locking portion 22 of the shaft support hole 21. At the same time, the guide rod 41 of the fixture 4 is drawn out to the lower end side of the microphone holder 2 through the drawing hole 23.

  Next, as shown in FIG. 4B, the insertion portion 31 of the insert fitting 3 is inserted into the flexible shaft 1 by inserting the flexible shaft 1 toward the shaft support hole 21, and the lower end thereof is the insert fitting. It stops at the position where it abuts against the third stopper 32.

  In this state, after fixing the lower end of the fixture 4 to a drive means (not shown), the fixture 4 is pulled downward via the drive means. When the fixture 4 starts moving while being pulled downward, the diameter-expanding head 42 provided at the tip enters the insertion portion 31 of the insert fitting 3 along the tapered surface 43, and inserts the insertion portion 31 into the inner side. The diameter increases from the outside to the outside.

  Further, as the fixture 4 moves downward, the insertion portion 31 is expanded in diameter while being plastically deformed outward by the diameter expansion head 42, and as shown in FIG. The flexible shaft 1 is crimped and fixed to the shaft support hole 21 of the microphone holder 2 by being drawn downward through.

  Thus, not only can the flexible shaft 1 be fixed to the microphone holder 2 very easily, but also electrical conduction between the flexible shaft 1 and the microphone holder 2 can be ensured at the same time.

  In this example, for example, a hydraulic pulling device or the like is used as the driving means. However, if the deformation stress is small, the mounting tool 4 may be pulled out using pliers or the like, and the driving means depends on the specifications. It can be arbitrarily deformed.

Industrial applicability

  In this embodiment, the flexible shaft 1 is illustrated as being attached to the microphone holder 2, but in addition to this, it may be a connecting means for connecting the flexible shafts. Furthermore, it may be applied to a joint structure when a flexible shaft is used as a rotating shaft for transmitting rotational force, and the fixing structure of the present invention can be applied in various modes as long as it is used as a fixing structure of the flexible shaft. It is applicable to.

1 is a schematic diagram of a condenser microphone device according to an embodiment of the present invention. Sectional drawing which shows the state which applied the fixing structure of the flexible shaft which concerns on one Embodiment of this invention to the microphone. Sectional drawing of insert metal fittings. (A)-(c): Explanatory drawing explaining the fixing procedure of a flexible shaft.

Explanation of symbols

1 Flexible shaft 2 Microphone holder 21 Shaft support hole 21
3 Insert metal fittings 31 Insertion part 32 Stopper 4 Fixing tool 41 Guide rod 42 Diameter expansion head M Condenser microphone device MU Condenser microphone unit P Prop

Claims (5)

At least two metals including an inner winding wound spirally and an outer winding wound spirally so as to enter between the inner windings on the outer peripheral surface side of the inner winding the flexible shaft made of wire material, in the fixed structure of the flexible shaft is fixed to cylindrical support in member made of a metal material,
Has a cylindrical insert fittings made of plastically deformable material that will be inserted along the inner circumferential surface of the flexible shaft, and expanded the insert fitting from inside, the flexible shaft to the inner surface of the support member A flexible shaft fixing structure characterized by being crimped and fixed while ensuring electrical continuity . At least two metals including an inner winding wound spirally and an outer winding wound spirally so as to enter between the inner windings on the outer peripheral surface side of the inner winding the flexible shaft made of wire material, in a fixing method of the flexible shaft is fixed to cylindrical support in member made of a metal material,
Insert the tubular insert fittings made of 塑 of deformable material along the inner peripheral surface of the flexible shaft, from one end side of the upper Symbol insert fitting the enlarged diameter section whose diameter increases the insert fitting from inside by moving toward the side, and diameter of the insert fitting from the inside of the flexible shaft fixing method characterized by crimped while ensuring electrical conduction to the inner surface of the upper Symbol support the flexible shaft . The insert fitting includes a cylindrical insertion portion that is inserted along the inner peripheral surface of the flexible shaft, and a flange portion that is formed on one end side of the insertion portion to be larger in diameter than the outer diameter of the insertion portion. has, in the support member, the fixing method of the flexible shaft of claim 2, wherein a stopper to receive the flange portion of the insert fitting is provided. The diameter expanding means is integrally provided with a guide rod having an outer diameter smaller than the inner diameter of the insert metal fitting and a diameter expanding head having an outer diameter larger than the inner diameter of the insert metal fitting. 4. The method for fixing a flexible shaft according to claim 2, wherein the diameter expansion head expands the diameter of the insert metal fitting from the inside by pulling out from one end side of the insert metal fitting to the other end side. It consists of at least two metal wires of an inner winding wound spirally and an outer winding spirally wound so as to enter between the inner windings on the outer peripheral surface side of the inner winding. Condenser microphone having a column including a flexible shaft that can be bent, a capacitor microphone unit attached to the tip of the column, and a cylindrical support member made of a metal material connected to the flexible shaft on the other end of the column In the device
It has a cylindrical insert fitting made of a plastically deformable material inserted along the inner peripheral surface of the flexible shaft, and the flexible shaft is crimped and fixed to the inner surface of the support member while ensuring electrical continuity. Therefore, the condenser microphone device is characterized in that the insert metal fitting is expanded from the inside by a predetermined diameter expanding means.

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