JPH0572425A - Optical fiber probe - Google Patents

Abstract

PURPOSE:To decrease the bleeding out of a laser beam without generating flaws and to suppress the generation of heat by holding an IR optical fiber with two sheets of semi-cylindrical holding members provided with V-grooves, thereby holding the IR optical fiber by line contact. CONSTITUTION:The graded hole 4b of a tightening ring 4 and the graded parts 5c of the semi-cylindrical holding members 5 do not come into contact with each other and two sheets of the semi-cylindrical holding members 5 are held open in a circumferential direction in the state of loosening the tightening ring 4. The IR optical fiber 1 is inserted in this state. The tightening ring 4 is then screwed, by which the graded hole 4b of the tightening ring 4 and the graded parts 5c of the semi-cylindrical holding members 5 are brought into contact with each other and two sheets of the semi-cylindrical holding members 5 are closed in a central direction. Namely, the IR optical fiber 1 is sandwiched and held by two sheets of the semi-cylindrical holding members 5. The IR optical fiber 1 held between the V grooves 5a is housed and protected without slipping at the end of a protective tube 2 by inserting the protective tube 2 between the flat grooves 5b of two sheets of the semi-cylindrical holding members 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber probe for guiding high-power laser light to a predetermined position in a laser processing machine or the like.

[0002]

_2. Description of the Related Art In recent years, attempts have been made to use an infrared optical fiber for guiding high-power CO ₂ laser light in a CO ₂ laser processing machine or the like. A halide such as KRS-5 is used as a material for the infrared optical fiber.

In a conventional optical fiber for communication, in order to limit modes, a clad having a slightly smaller refractive index than the core is provided on the outer periphery of the core, and the outer periphery is covered with plastic or the like for reinforcement. is there.

However, in the far infrared region such as CO ₂ laser light, there is no suitable clad material suitable for this, and the coating is not preferable from the viewpoint of the heat radiation effect of the infrared optical fiber. Therefore, as the configuration of the optical fiber probe,
Infrared optical fiber is not clad (air clad)
The core is used as it is, and it is loosely stored in a protective tube. However, the infrared fiber and the protective tube must be locked somewhere.

An example of a conventional optical fiber probe will be described below with reference to the drawings.

FIG. 5 shows an infrared optical fiber holding portion of a conventional optical fiber probe. In FIG.
Reference numeral 21 is an infrared optical fiber. Reference numeral 22 is a protective tube made of a metal tube such as stainless steel, and accommodates and protects the infrared optical fiber 21. 23 is a chuck having one end having a slope shape, and has a slit 23a, a loose insertion hole 23b, and a small-diameter portion 23c having substantially the same diameter as the infrared optical fiber 21. Two
Reference numeral 4 denotes a pressing ring, and the pressing spring 25 is urged between the pressing ring 24 and the fixture 26. The protection tube 2
2 and the chuck 23 are integrally fixed to the fixture 26 by press fitting or screws. In the infrared optical fiber 21 inserted into the chuck 23, the pressing ring 24 urged by the pressing spring 25 is attached to the chuck 2
By pressing the sloped portion 3 of FIG. 3, it is sandwiched by the small diameter portion 23c.

[0007]

The infrared optical fiber is
When laser light is incident from one end surface, most of the laser light is emitted from the other end surface. At that time, if there is a scratch on the infrared optical fiber, the laser light will be diffusely reflected and scattered at that portion, and the laser light will not be effectively transmitted through the infrared optical fiber, and the laser light output from the laser processing machine will be high. When transmitting the heat, the scratched part is heated and becomes a factor of burning.

Further, when light is transmitted by total internal reflection in the infrared optical fiber, there is light bleeding from the outer peripheral surface though it is slightly (distance of approximate wavelength), and this is absorbed by the holding part, which causes The holding part becomes hot and the infrared optical fiber is burned. Therefore, there is a demand for a method of holding an infrared optical fiber that eliminates these problems.

However, in the above-mentioned structure, the infrared optical fiber 21 is in close contact with the small diameter portion 23c of the chuck 23, which is a holding portion, by surface contact (the range excluding the slit 23a), and it is easy to absorb the bleeding light, Further, since the pressing ring 24 is urged by the pressing spring 25, if the spring pressure is weak, it cannot be held securely, and if it is strong, the edge of the slit 23a damages the infrared optical fiber 21.

In view of the above problems, it is an object of the present invention to provide an optical fiber probe equipped with a holding mechanism for an infrared optical fiber that hardly absorbs the bleeding light and is not easily scratched.

[0011]

In order to solve the above problems, an optical fiber probe of the present invention comprises an infrared optical fiber, a protective tube for housing and protecting the infrared optical fiber, and an optical fiber provided on both ends of the infrared optical fiber. Consisting of members,
Sandwiching the infrared optical fiber and the protective tube,
The holding mechanism includes a semi-cylindrical holding member having a V groove and a slope portion, and a tightening member having a slope hole for loosely and rapidly tightening the semi-cylindrical holding member.

[0012]

According to the present invention, by holding the infrared optical fiber by line contact instead of surface contact by the above-mentioned constitution, scratches are not caused and absorption of oozing light is reduced to suppress heat generation.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical fiber probe according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of an optical fiber probe according to an embodiment of the present invention. In FIG.
Reference numeral 1 is an infrared optical fiber, and 2 is a protection tube made of a metal tube such as stainless steel, which protects the infrared optical fiber 1 by housing. Reference numeral 3 is a holder into which the semi-cylindrical holding member 5 is inserted. This holder 3 has an opening screw 3a at one end and the protection tube 2 is integrally fixed at the other end by adhesion or the like. Reference numeral 4 is a tightening ring, which has a screw portion 4a on the outer periphery which is screwed into the opening screw 3a of the holder 3,
It has a hole 4b having a gradient shape inside.

As shown in FIG. 2, the semi-cylindrical holding member 5 has a shape in which a cylinder whose both ends are sloped is cut vertically to be slightly below the center of the circle, and has a V-shaped groove 5a and a flat groove 5b on its flat surface. ..
The gradient portion is 5c. The V groove 5a has a depth such that a gap is formed between the respective semi-cylindrical holding members 5 when the infrared optical fiber 1 is sandwiched by the two semi-cylindrical holding members 5, and the length thereof is 10 m.
It is m or more. The flat groove 5b is a groove for sandwiching the protective tube 2 between the two semi-cylindrical holding members 5.

Reference numeral 6 denotes an inlet side connector into which the holder 3 is inserted and fixed with screws or the like. A window 8 which is an optical member for transmitting laser light is fixed to one end, and the other end is one end of a jacket tube 7. Is fixed. Reference numeral 9 is a lens holder fixed to the other end of the protection tube 2, and a condenser lens 10 for condensing the laser light transmitted through the infrared optical fiber 1 is fixed. 11 is a handpiece. The inlet-side connector 6 is provided with an assist gas hole 6a, and the assist gas passes between the protective tube 2 and the jacket tube 7, and the lens holder 9
And out of between the handpiece 11.

The method of holding the infrared optical fiber of the optical fiber probe configured as described above will be described below with reference to FIG.
The operation will be described with reference to (a), (b) and FIGS. 4 (a), (b). 3 (a) and 4 (a) are partial enlarged sectional views of the holding mechanism of the present embodiment.
(B) and FIG.4 (b) are those AA arrow line views.

3 (a) and 3 (b) show a state in which the tightening ring 4 is loosened. In this state, the inclined hole 4b of the tightening ring 4 and the inclined portion 5c of the semi-cylindrical holding member 5 are shown. , But the two semi-cylindrical holding members 5 are open in the circumferential direction. In this state, the infrared optical fiber 1 is inserted. Next, by screwing the tightening ring 4 in FIG.
As shown in (a) and (b), the inclined hole 4b of the tightening ring 4 and the inclined portion 5c of the semi-cylindrical holding member 5 come into contact with each other, and the two semi-cylindrical holding members 5 are closed toward the center. Be done.
That is, the infrared optical fiber 1 is held by being sandwiched between the two semi-cylindrical holding members 5.

Further, by sandwiching the protective tube 2 between the flat grooves 5b of the two semi-cylindrical holding members 5, the V groove 5 is formed.
The infrared optical fiber 1 held between a and a is stored and protected at the end of the protective tube 2 without being displaced.

As described above, according to this embodiment, the infrared optical fiber 1 is provided with the two semi-cylindrical holding members 5 each having the V groove 5a.
It can be held in line contact by sandwiching
The bleeding of the laser light from the infrared optical fiber 1 is reduced. Further, by setting the range held by the line contact to 10 mm or more, even if the semi-cylindrical holding member 5 absorbs the oozing light, the heat dissipation effect is high and the heat generation is suppressed, and the infrared optical fiber 1 is prevented from being burned. Further, by making surface contact between the inclined portion 5c of the semi-cylindrical holding member 5 and the inclined hole 4b of the tightening ring 4, the force at the time of screwing the tightening ring 4 is dispersed and applied to the infrared optical fiber 1. , The local stress that causes scratches disappears,
It can be held securely and is not scratched.

[0021]

As described above, according to the present invention, an infrared optical fiber is provided by a holding mechanism for loosely and rapidly tightening a semi-cylindrical holding member having a slope and forming a V groove with a tightening member having a sloped hole. It can be held in line contact, so that scratches do not occur and bleeding out of laser light can be reduced, and heat generation can be suppressed.

[Brief description of drawings]

FIG. 1 is a sectional view showing the configuration of an embodiment of an optical fiber probe of the present invention.

FIG. 2 is a perspective view of a semi-cylindrical holding member of the same embodiment.

3A is a partially enlarged cross-sectional view showing a holding release operation of the holding mechanism of the embodiment, and FIG. 3B is a cross-sectional view taken along the line AA in FIG. 3A.

4A is a partially enlarged cross-sectional view showing a holding operation of the holding mechanism of the embodiment, and FIG. 4B is a cross-sectional view taken along the line AA in FIG. 4A.

FIG. 5 is a sectional view of a holding portion of a conventional optical fiber probe.

[Explanation of symbols]

 1 Infrared Optical Fiber 2 Protective Tube 3 Holder 4 Tightening Ring 4b Gradient Hole 5 Semi-Cylinder Holding Member 5a V Groove 5c Gradient

Claims (1)

[Claims] 1. A V-shaped groove comprising an infrared optical fiber, a protective tube for housing and protecting the infrared optical fiber, and an optical member provided on both ends of the infrared optical fiber, for sandwiching the infrared optical fiber and the protective tube. An optical fiber probe, comprising: a holding mechanism including a semi-cylindrical holding member having a sloping portion, and a tightening member having a grading hole for tightening the semi-cylindrical holding member slowly and freely.