JP2001032816A - Flexible shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively provide a flexible shaft in which the outside diameter can be fixed without requiring dimensional adjustment or secondary working of a cut end surface. SOLUTION: In a flexible shaft consisting of at least two wires, namely an inner coil spirally wound at a fixed pitch, and an outer coil spirally wound around the outer periphery of the inner coil 2 so as to cover the inner coil 2, a cap 4 made of resin material is integrally fastened to at least one end. In this case, the outer diameter of the end part of the flexible shaft is determined without further consideration by the outside diameter of the cap. Thus, the outside diameter of the end part of the flexible shaft can be constant without secondarily working the cut end surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bendable flexible shaft, and more particularly, to a flexible shaft end treatment structure in which a cap made of a resin material is integrally formed at an end of the flexible shaft. .

[0002]

2. Description of the Related Art A flexible shaft is a flexible rod composed of at least two wires. That is, as shown in the cross-sectional view of FIG. 5, the flexible shaft 1 has an inner winding 2 spirally wound at a predetermined pitch, and an inner winding 2 on the outer peripheral surface of the inner winding 2 having a pitch of 21 mm.
Along with the outer winding 3 wound spirally.

The outer winding 3 has, for example, a triangular cross section so as to be in contact with the pitch 21 of the inner winding 2, and its vertex 31 is inserted into the pitch 21 of the inner winding 2. And is fixed on the inner winding 2.

The inner winding 2 is usually formed of a metal material such as a spring steel or stainless steel, and the outer winding 3 is usually formed of a non-ferrous metal material, but may be formed of a steel material. The outer winding 3 is generally formed in a triangular cross-section, but may be formed in other shapes.

The thus constructed flexible shaft 1 is bent in an arbitrary direction by the bending and torsion elastic force of the metal wire (winding) and the frictional force between the inner winding 2 and the outer winding 3, and the state is changed. Can be held. That is, it has a holding property. In terms of production efficiency, the flexible shaft 1 is manufactured to have a length of several meters to several tens of meters.
The user cuts the flexible shaft to an arbitrary length using a cutting means such as a cutter for rotating a thin disk-shaped grindstone, and uses it.

[0006]

When the flexible shaft is cut by the above-mentioned cutter, as shown in FIG. 6, due to the restoring force of the metal wire, the cut end face (lower side in the figure) is deformed so as to be divergent, and many points are formed. In this case, the enlarged diameter portion 22 is formed. That is, when the outer diameter of the flexible shaft is A and the outer diameter of the end portion is B, not only A <B may occur, but also the expanded outer diameter B of the end portion is not constant.

For this reason, when connecting the end (the enlarged diameter portion 22) of the flexible shaft to another solid, for example, a receiving cylinder (cylindrical receiving), the dimension of the receiving cylinder is increased. Part 2
It is necessary to keep it larger than 2. Usually, the end of the flexible shaft is fixed with an adhesive in the cylinder, or the receiving cylinder is fixed by caulking with a press, but since the end outer diameter B is not constant, the end of the adhesive is fixed. Adjustment of required coating amount and adjustment of caulking dimensions are required, and fixing strength is not stable.

Therefore, the end face of the flexible shaft is
The next processing is performed. As a first method of the secondary processing, as shown in FIG. 7, a cylindrical grindstone 4 having an inner diameter substantially the same as the outer diameter A of the flexible shaft 1 is inserted while rotating from the end of the flexible shaft. Polishing to make the diameter of the flexible shaft uniform.

As a second method, as shown in FIG. 8, a caulking member 6 having an inverse taper with respect to the enlarged diameter portion 22 of the flexible shaft 1 is attached to the enlarged diameter portion 22 and gradually caulked. , Compress the outer diameter of the end. Although the dimensions of the flexible shaft are stabilized by these secondary processings, it is undeniable that productivity is degraded by the secondary processing.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a method of manufacturing a semiconductor device which has an end portion without requiring a secondary processing of a cut end surface for dimensional adjustment. An object of the present invention is to provide an inexpensive flexible shaft having a constant outer diameter.

[0011] To achieve the above object, the present invention provides
An inner winding wound spirally at a predetermined pitch, and a flexible shaft made of at least two wires of an outer winding wound spirally around its outer periphery so as to cover the inner winding, At least at one end, a cap made of a resin material is integrally fixed. According to this, the outer diameter of the end portion of the flexible shaft is uniquely determined by the outer diameter of the cap. Therefore, the outer diameter of the end portion of the flexible shaft can be made constant without performing the secondary processing of the cut end surface.

[0012] The cap may be forcibly fitted to one end of a flexible shaft, but is preferably formed by resin molding in a molding die into which one end of the flexible shaft is inserted as an insert. According to this, after release, it can be used as it is without post-processing.

[0013]

Next, embodiments of the present invention will be described with reference to the drawings. In addition, the same reference numerals are given to portions which are the same as or are considered to be the same as the conventional example.

As shown in FIG. 1, this flexible shaft 10 is spirally wound at a predetermined pitch in the same manner as in the above-described conventional example, and has an inner winding 2 having a hollow inside, and a space between the inner winding 2 and the pitch. The outer winding 3 is spirally wound around the outer periphery of the outer winding 3 along the line 21.

At the end (lower side in the figure) of the flexible shaft 10, an enlarged portion 22 generated at the time of cutting is formed, but the end (the enlarged portion 2) of the flexible shaft 10 is formed.
A hollow cylindrical cap 4a is integrally fixed to the outer periphery from 2) to the undeformed portion by injection molding. This cap 4a is made of, for example, a thermoplastic resin such as ABS resin or polycarbonate, and is shown in FIG.
For example, it is formed in a predetermined shape so as to be connected to the insertion port of the microphone holder H.

Next, a mold for injection molding of the cap 4 fixed to the flexible shaft of the present invention will be described. FIG. 2 is a perspective view of the mold, and FIG. 3 is a longitudinal sectional view showing a state where an end of the flexible shaft 10 is inserted into the mold.

The mold 7 is composed of a combination of three mold members. The first mold member 7a and the second mold member 7b, each of which has a semi-cylindrical shape having a U-shaped cross section, and the cylindrical third mold member 7b. And a mold member 7c. The mold 7 is attached to an injection molding machine (not shown).

The first mold member 7a and the second mold member 7b are bilaterally symmetrical, and are fitted into semi-cylindrical hollow portions 71a, 71b filled with resin and the outer peripheral surface of the flexible shaft 10. Seal portions 72a, 7
2b and an insertion hole 7 into which the third mold member 7c is inserted.
3 are provided.

Injection holes 74a and 74b for resin to be injected into the hollow portions 71a and 71b are formed in the outer periphery of the first mold member 7a and the second mold member 7b, respectively. The third mold member 7c integrally includes a base 71c formed of a cylindrical body having a diameter larger than at least the insertion portion 73, and a protrusion 72c formed coaxially at one end of the base 71c. The projection 72c has a diameter substantially equal to the inner diameter of the flexible shaft 10.

In order to integrally form the cap 4 at the end of the flexible shaft 10 by using the mold 7, first, the first enlarged diameter portion 22 is firstly inserted from both sides so as to be housed in the hollow portions 71a and 71b. The mold member 7a and the second mold member are attached to the flexible shaft 10. At this time, the undeformed portion of the flexible shaft 10 is
Sealed by 2a, 72b.

Next, the projecting portion 72 of the third mold member 7c is inserted into the insertion portion 73 of the first mold member 7a and the second mold member 7b which are aligned with the end of the flexible shaft 10.
c is inserted. The convex portion 72c has substantially the same diameter as the flexible shaft 10 as described above,
By inserting the convex portion 72 c into the enlarged diameter portion 22, the tip of the convex portion 72 c is pushed into the flexible shaft 10.

Thereafter, the molten resin is injected from the injection holes 74a, 74b of the first and second mold members 7a, 7b, and the hollow portion 71 is filled with the resin. At this time, since the protrusion 72c is inserted into the flexible shaft 10, there is no possibility that the resin enters the inside of the flexible shaft 10.

After confirming that the resin has hardened, the third mold member 7c is first pulled out, contrary to the procedure for assembling the mold.
Next, by opening the first and second mold members 7a and 7b, the flexible shaft 10 having the cap 4 integrally fixed to the end is removed from the mold 7.

An example of use of the flexible shaft 10 will be described with reference to FIG. In this example, the flexible shaft 10 is applied to a support stem of a microphone.
A microphone unit M is attached to the tip (upper end) of the flexible shaft 10, and the cap 4 on the other end is inserted into an insertion port of a microphone holder H fixed to a table or the like (not shown).

The micro holder H and the cap 4 are fixed with, for example, an adhesive or a set screw. In any case, since the outer diameter of the cap 4 of the flexible shaft 10 is constant, the diameter of the enlarged diameter portion 22 is reduced. It can be directly attached to the microphone holder H without further processing.

According to this usage example, the microphone unit M can be used in any direction by utilizing the bending property of the flexible shaft 10. It should be noted that the flexible shaft 10 can be cut in the middle and connected with a nested slide pipe to form a flexible shaft that can expand and contract.

The simplest form of the cap 4 is to simply form it into a cylindrical body having a smooth surface. In addition, a female screw is formed on the inner surface of the mold, and a male screw is formed on the cap 4 simultaneously with injection molding. It is also possible to transfer the screw. Such an embodiment is also included in the present invention.

In the above embodiment, the flexible shaft 1
A wire formed by winding two wires is used as 0, but a multi-turn flexible shaft composed of three or more wires may be used. Further, the cap 4 may be molded using a thermosetting resin such as an epoxy resin. That is, put the thermosetting resin in the mold,
By pressing and heating to cure the resin, a cap similar to that of the above embodiment can be obtained.

Further, the cap 4 may be integrally formed with the flexible shaft which has been subjected to the secondary processing (polishing processing using a grindstone, caulking processing, etc.) described as a conventional example by the above-mentioned forming means. Since the dimensional accuracy of the mold is several steps higher than the dimensional accuracy of the secondary processing, it is effective in further increasing the accuracy of the outer diameter of the end.

[0030]

As described above, according to the present invention,
By integrally fixing the cap to the end of the flexible shaft, it is possible to provide a flexible shaft that does not require secondary processing of the end for dimension adjustment.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an end of a flexible shaft according to an embodiment of the present invention.

FIG. 2 is a perspective view of a mold for integrally molding a cap at an end of the flexible shaft.

FIG. 3 is a longitudinal sectional view showing a state where the flexible shaft is inserted into the mold.

FIG. 4 is an explanatory view showing a usage example of the flexible shaft of the embodiment.

FIG. 5 is a longitudinal sectional view of a conventional flexible shaft.

FIG. 6 is a longitudinal sectional view showing a cut state of an end of a conventional flexible shaft.

FIG. 7 is a longitudinal sectional view showing a state where an end of a conventional flexible shaft is subjected to secondary processing.

FIG. 8 is a longitudinal sectional view showing a state in which the end of a conventional flexible shaft is subjected to secondary processing by another method.

[Explanation of symbols]

 1,10 Flexible shaft 2 Inner winding 3 Outer winding 4 Cap 5 Grinding stone 6 Caulking member 7 Mold 7a First mold member 7b Second mold member 7c Third mold member 21 Pitch 71a, 71b Hollow portion 71c Base 72a, 72b Seal 72c Convex 73a, 73b Insertion 74a, 74b Injection hole H Microphone holder M Microphone

Claims (2)

[Claims] At least two wires consisting of an inner winding spirally wound at a predetermined pitch and an outer winding spirally wound around the outer periphery so as to cover the inner winding. A flexible shaft, wherein a cap made of a resin material is integrally fixed to at least one end thereof. 2. The flexible shaft according to claim 1, wherein the cap is formed by resin molding in a molding die into which one end of the flexible shaft is inserted as an insert.