JPS63102862A - Grinding attachment for optical fiber ferrule end face - Google Patents

Abstract

PURPOSE:To make even such a work surface small in a radius of curvature polishable in a highly form accurate manner, by pressing a ferrule end face to a polishing surface, rotating a holding device, and making it perform its rocking motion, then polishing the ferrule end face into a convex spherical form. CONSTITUTION:A ferrule 1 is clamped to a ferrule holder 4 with a clamp screw 5 for retention, and an abrasive surface plate 6 is tilted so as to cause the center axis to be passed through a concave spherical center axis of a ring abrasive belt of the abrasive surface plate 6, positioning it, whereby a distance between a spherical bearing 7 and a ferrule end face 110, namely, a radius of curvature is adjusted by a slide adjusting screw 10. Nest, a driving driving friction 14 is driven clockwise or counter-clockwise an eccentric friction wheel 16 is rotated in one direction, giving rotation reversal motion and rocking motion to the ferrule 1, and the surface plate 6 is driven into rotation, thus the ferrule end faced 110 is polished at high speed. Thus, spherical polishing for even such a work surface as small in a radius curvature is performable so excellent in spherical form accuracy, besides less in eccentricity.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a polishing device for optical fiber connectors, and more specifically, it is a compact, highly efficient, and highly accurate polishing device for polishing optical fiber connectors with a spherical shape. This relates to a device for polishing into shapes.

BACKGROUND OF THE INVENTION Generally, a ferrule used in an optical fiber connector is constructed as shown in FIG.

The illustrated ferrule 1 for an optical fiber connector has a through hole 120 for accommodating the optical fiber 2 in the center. The optical fiber 2 inserted from the rear part of the ferrule 1 is firmly held at the distal end surface 110 of the ferrule 1 by the adhesive 3.

In order to propagate an optical signal without loss, it is necessary to abut the two ferrule end faces 110 and join the fiber end faces without misalignment of the fiber axes and without any gaps. For this purpose, it is necessary to polish the end surface 110 to make it a flat surface perpendicular to the fiber axis, or to make it a spherical surface with the fiber portion at the top, and to make it smooth with no step between the ferrule end surface and the fiber end surface. .

In order to polish the end face of the ferrule in this manner, an optical fiber ferrule end face polishing apparatus, the main part of which is shown in FIG. 3, has conventionally been used.

The illustrated optical fiber end face polishing apparatus includes a ferrule holder 4. As shown in FIG. At least three ferrules are held in the ferrule holder 4 by tightening screws 5.

Furthermore, a rotating polishing surface plate 6 installed on a base (not shown) is provided. An abrasive is supplied from a nozzle 61 between the polishing surface of the rotary polishing surface plate 6 and the end surface of the ferrule pressed perpendicularly to the line surface.

The optical fiber ferrule end face polishing apparatus configured as described above operates as follows.

A plurality of ferrules 1 are fastened to a ferrule holder 4 with screws 5, and the end faces of the ferrules are pressed against a polishing surface plate 6. While supplying the abrasive from the abrasive supply nozzle 61, the polishing surface plate 6 is rotated by a surface plate driving means (not shown). At the same time, the ferrule holder 4 is rotated or circularly oscillated (precessed) by a holder driving means (not shown) to polish the ferrule end face.

Ferrules made of hard materials such as ceramics are processed with high efficiency into a fixed shape, and the final surface has a maximum of 0.0 unevenness.
To finish to a mirror surface of about 1 μm, two processes such as rough polishing and finishing workshop are required depending on the grade and efficiency of the machined surface.
Up to three polishing steps are required. Therefore, a laboratory apparatus is used which is equipped with two or three rotating surface plate parts similar to the illustrated processing head.

That is, when using such a conventional optical fiber connector end face polishing device, the first step is to polish the optical fiber 2 and adhesive 3 protruding from the ferrule end face 110.
are processed to align with the ferrule end face 110, and then the ferrule end face is cleaned in an ultrasonic cleaning tank. Next, a second and third laboratory process and a cleaning operation after each process are performed to process the tip surface of the ferrule into a flat surface. During this time,
Workers had to carry out each process manually, resulting in extremely poor work efficiency.

FIG. 4 shows a schematic diagram of an optical fiber ferrule end face polishing apparatus for polishing the ferrule end face and fiber end face into a spherical shape.

The illustrated laboratory apparatus is very similar in construction and operation to the apparatus of FIG. The difference in configuration is the polishing surface plate 60.
The two points are that the surface is formed into a concave spherical surface having a predetermined curvature, and that the ferrule holder is configured such that the central axis of each ferrule passes through the center of the spherical surface of the surface plate. The difference in operation is that the ferrule holder 4 does not rotate, but only swings in a circular manner.

When processing the ferrule end face into a spherical shape, first
Rough polishing is performed using the planar surface plate shown in the figure to remove the protrusion of the optical fiber and the adhesive. Next, it was necessary to remove the ferrule processed in this manner and attach it to the ferrule holder of the polishing apparatus for spherical surface processing shown in FIG. 4 for processing, which resulted in particularly poor work efficiency. Further, when the illustrated spherical surface plate deforms in the laboratory, another dedicated device is required to correct the deformation, resulting in the problem of additional effort and time.

Furthermore, in the above-described ferrule holding method, the ferrule itself is not rotated, so the center symmetry of the processed ferrule end face is low.

For this reason, when the optical fibers are connected by abutting the connectors against each other, there is a problem that a gap is created between the optical fiber cores, resulting in a large optical signal propagation loss. Furthermore, since the ferrule holder holds the plurality of connectors so that the central axis of each connector passes through the center of the spherical surface of the surface plate, it is possible to process the ferrule end face using two side-by-side surface plates with a small radius of curvature. It was impossible to process it into a spherical shape.

Problems to be Solved by the Invention As described above, in order to precisely process the ferrule end face of an optical fiber connector into a spherical shape, it is necessary to go through several polishing steps. At that time, with conventional polishing equipment, the polishing surface plate must be replaced manually each time the polishing process progresses.
There was a problem in that the efficiency of polishing work was extremely poor.

Further, in the conventional ferrule holding method, each ferrule is not rotated, so there is a problem in that the center symmetry of the ferrule end face is low. Furthermore, in the conventional ferrule holding method, multiple connectors are held so that the central axis of each connector passes through the center of the spherical surface of the surface plate, so it is possible to polish the ferrule end face into a spherical shape with a small radius of curvature. The problem was that I couldn't do it.

Therefore, the present invention aims to provide an optical fiber ferrule end face polishing device that can reduce the number of polishing processes compared to the conventional method, shorten the polishing time in each process, and improve the machining accuracy of the end face of the connector. be.

Furthermore, the present invention aims to provide a compact, highly efficient, and highly accurate optical fiber ferrule end face polishing device that is equipped with a novel polishing grindstone, a ferrule movement mechanism, and a polishing grindstone movement mechanism.

Means for solving the problem, that is, according to the present invention, is an apparatus for polishing the end face of a ferrule into which an optical fiber is inserted and fixed into a spherical shape, comprising: a polishing means having a polishing surface; and a polishing means having a polishing surface; A means for holding the ferrule so as to press against the polishing surface, and a driving means for driving the holding means to cause the ferrule to rotate about its axis and swing about an axis perpendicular to the axis. , pressing the ferrule end face against the polished surface and rotating and swinging the holding means;
An optical fiber ferrule end face polishing device is provided, which polishes the end face of the ferrule into a convex spherical shape.

As described above, in the optical fiber ferrule end face polishing apparatus of the present invention, a single optical fiber ferrule is held and rotated and oscillated to polish the ferrule end face.

In this way, since a single optical fiber connector is held and rotated and oscillated, the shape accuracy of the spherical surface is high, and the eccentricity of the spherical apex from the center of the optical fiber core can be reduced.

Furthermore, by adjusting the distance between the center of the rocking motion and the tip of the ferrule, the radius of curvature of the polished surface at the tip of the ferrule can be set, and processing with a small radius of curvature is also possible.

Furthermore, as mentioned above, the surface plate and connector have a stable setting posture, and the surface plate can be rotated at high speed to perform accurate machining, so the entire process can be completed in two steps: rough polishing and final polishing. becomes possible.

In addition, the polishing apparatus of the present invention is equipped with means for changing the swing radius by moving the swing fulcrum of the ferrule holding means, so that when processing the ferrule end face into a spherical shape with a different radius of curvature, the ferrule holder does not require replacement.

Embodiments Hereinafter, embodiments of the optical fiber ferrule end face polishing apparatus of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of an embodiment of an optical fiber ferrule end face polishing apparatus according to the present invention.

The illustrated optical fiber ferrule end face polishing device has a rotating shaft 2
A polishing surface plate 6 fixed at 0 and having a concave spherical annular polishing zone
It is equipped with The rotating shaft 20 is configured to be tiltable and is driven by a drive means (not shown), and as a result, the polishing surface plate 6 is rotationally driven around the rotating shaft 20.

The device includes a ferrule holder 4 that holds a ferrule 1 of an optical fiber connector. The ferrule holder 4 has a cylindrical outer shape and has a cylindrical through hole inside, and the diameter of the cylindrical through hole is made smaller at the tip, that is, at the front. The ferrule 1 that accommodates and holds the optical fiber 2 passes through the ferrule holder 4 from the rear part to the front part L, and the ferrule is tightened by the chuck 24 at a position where the ferrule end surface 110 slightly protrudes from the front end surface of the ferrule holder 4. It is held fixed.

The ferrule tightening kechak 24 is attached to the ferrule holder 4
The clamp mounted on the rear end face of the ferrule is driven by the screw 5 and displaced in the axial direction within the ferrule holder 4, so that the ferrule clamp moves between the state and the ferrule released state.

The ferrule holder 4 includes a driven friction wheel 11 coaxially attached to the ferrule holder at its upper end. The driven friction wheel 11
In this case, the pressing is performed by the idler rotating wheel 12 biased by the spring 13.
are pressing against each other. A driving friction wheel 14 is further pressed into contact with the driven friction wheel 11 . The shaft of this driving friction wheel 14 is
It is swingably and rotatably supported by means not shown, and the three
It is designed to be able to rotate forward and backward at a rotation angle of 60 degrees or more. Furthermore, another friction wheel 15 is coaxially mounted on the shaft of the driving friction wheel 14 and is rotatable with respect to the shaft of the driving friction wheel 14 . An eccentric rotating friction wheel 16 is pressed against the friction wheel 15 . The shaft of the eccentric rotating friction wheel 16 is rotationally driven by a driving means (not shown).

Furthermore, the ferrule holder 4 is held by a spherical bearing 7 below the driven friction wheel 11 so that its position can be adjusted in the axial direction. The spherical bearing is supported by a spherical bearing support 8. This spherical bearing support 8 is movable along a slide shaft 9, and its position is adjusted along the slide shaft 9 by an adjustment screw 10.

Further, a shifting force is applied to the spherical bearing support 8 in advance so as to press the ferrule against the polishing surface plate 6. Alternatively, the circumferential surface of the friction wheel 14 is made into a partially spherical surface, and the force that pushes the ferrule holder 4 toward the polishing surface plate 6 is applied depending on the contact position of the idler rotating wheel 12 and the friction wheel 14 to the partially spherical surface. You can do it like this.

The apparatus further includes a nozzle 61 that supplies abrasive between the ferrule end face 110 and the concave spherical annular polishing zone of the polishing surface plate 6.

The optical fiber connector end face polishing apparatus configured as described above operates as follows.

For tightening, the ferrule of the connector is inserted from behind the screw 5 using a jig (not shown), and for tightening the ferrule, the ferrule 4 is pushed out by the screw 5 to hold the ferrule 1 fixed. The polishing surface plate 6 is tilted to position the polishing surface plate 6 so that the central axis of the ferrule holder 4 passes through the central axis of the concave spherical surface of the annular polishing zone of the polishing surface plate 6. According to the radius of curvature of the processed spherical surface, the spherical bearing support 8 is moved up and down by the slide adjustment screw 10, and the spherical bearing 7 is accordingly moved along the ferrule holder 4, and the spherical bearing 7 and the ferrule end face 110 are Adjust the distance, that is, the swing radius.

In this state, the ferrule end face is pressed against the surface plate surface.

In this state, the shaft of the drive friction wheel 14 is driven to rotate forward and backward, and the eccentric rotary friction wheel 16 is driven to rotate in one direction, giving the ferrule 1 a rotational reversal motion and a rocking motion, while rotating the surface plate 6. The ferrule end face 110 is polished at high speed. That is, the shaft of the driving friction wheel 14 is driven to rotate in reverse, giving the driven friction wheel 11 a rotationally reverse motion. On the other hand, by rotating the shaft of the eccentric rotating friction wheel 16 at a low speed, the rotating shaft of the driving friction wheel 14 undergoes a rocking motion. In response to this rotational reversal motion and swinging motion, the ferrule end face 110 performs a rotational reversal motion and a rocking motion using the spherical bearing 7 as a fulcrum.

The swing width of the ferrule tip shall be equal to the contact width of the surface plate.

On the other hand, the idler rotating wheel 12, which is biased by a spring 13, always presses the driven friction wheel 11 against the driving friction wheel 14. This allows the ferrule tip to swing on the surface of the surface plate according to the movement of the eccentric rotating friction wheel 16. In other words, a uniform locus can be drawn over the entire surface of the polishing surface plate 6, allowing highly accurate polishing.

As the polishing surface plate 6, a spherical metal device with a radius of curvature of 30 mm and a metal-bonded diamond grinding wheel with a thickness of about 50 μm formed by electroforming are used.
11) Rotated at Orpm. The grain size of the diamond grindstone is approximately 2 μm to 3 μm. A ferrule made of ceramics (alumina, zirconia, etc.) with a flat tip and an outer diameter of 2.5 mm has an optical fiber fixed with adhesive.
It was fixedly held at the tip of the ferrule holder 4. The distance between the ferrule end face 110 and the spherical bearing 7 is adjusted to about 30 mm using the slide adjustment screw 10, and the ferrule holder 4 is given a rotational reversal motion of about 2 (11) orpm (reversed every 1.5 revolutions). and polished for 1 minute. As a result, both the ceramic ferrule end face and the optical fiber end face are
Surface roughness with unevenness of 0.2 μm or less and radius of curvature of approximately 30
A machined surface of mm was obtained.

Next, using a spherical tool made of tin and various resins as a polishing surface plate, diamond particles of 1 to 2 μm or Al
While supplying a suspension of various oxide fine particles such as 2O3, SiC2, ZrO2, CaC2, Fe*O<, etc., the end face of the ferrule which had been roughly polished into the convex spherical surface was finally polished. The rotation speed of the polishing surface plate 6 is set to 30 to 1 (11) rI]fTl, and the ferrule holder is also set to 30 to 1 (11) rprn.
caused rotation and reversal motion. As a result, we have created a high-precision machined surface in which the surface roughness of the optical fiber core end face is 30 to 508 or less, the radius of curvature of the entire end face including the ferrule is approximately 30 m + n, and the eccentricity of the tip apex from the core center is 20 μm or less. Obtained.

As explained above, the optical fiber ferrule end face polishing apparatus described above holds a single ferrule 1 and polishes it by rotating and rotating it. Therefore,
The tip of the ferrule can be machined into a spherical surface with excellent central symmetry. Furthermore, since a single ferrule is processed, it is possible to polish a processed surface with a small radius of curvature.

Furthermore, when the ferrule is located at the center of the ferrule's swing, the tip of the ferrule is positioned perpendicularly to and above the center of the annular spherical polishing zone of the polishing surface plate 6;
The polishing surface plate 6 is tilted. In this state, when the ferrule end face is swung so as to come into sliding contact with the spherical surface plate, the left and right inclination angles of the ferrule holder are the same with respect to the vertical axis, and a stable setting posture is possible. As a result, even if the surface plate is rotated at high speed and the end face of the ferrule is machined, it can be machined with high accuracy, so that machining can be performed more efficiently than before.

In addition, the above-described optical fiber ferrule polishing apparatus positions the swing center of the optical fiber ferrule at the center of the annular spherical polishing zone of the polishing surface plate 6, and the rotation axis of the annular spherical polishing zone of the polishing surface plate 6 is located at the center of the annular spherical polishing zone of the polishing surface plate 6. It is inclined with respect to the holder 4. Therefore, even if the ferrule 1 swings, the ferrule 1 is always in contact with the polishing surface of the annular spherical polishing zone of the polishing surface plate 6, and the part of the annular spherical polishing zone that the ferrule 1 is in contact with are always in a vertical relationship. Therefore,
The polishing surface of the annular spherical polishing band wears uniformly and is not locally worn and deformed.

As described in detail, the optical fiber ferrule end face polishing apparatus of the present invention holds a single ferrule and polishes it by rotating and oscillating it. Therefore, it is possible to polish a machined surface with a small radius of curvature, and furthermore, the shape accuracy of the spherical surface is high, and the eccentricity of the apex of the spherical surface from the center of the optical fiber core can be reduced.

Furthermore, when the ferrule end face is swung so that it comes into sliding contact with the polishing surface, a stable polishing posture can be obtained by making the left and right inclination angles of the ferrule holder the same with respect to the central axis of oscillation. . As a result, even if a high-speed rotating polisher is used for polishing, the end face of the ferrule can be processed with high accuracy, resulting in more efficient processing than before.

In addition, the optical fiber ferrule polishing apparatus of the present invention is equipped with means for changing the swing radius by moving the swing fulcrum of the ferrule holding means, so that when processing the ferrule end face into a spherical shape with a different radius of curvature, No need to replace ferrule holder.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the mechanism of the first embodiment of the optical fiber ferrule end face polishing apparatus of the present invention, FIG. 2 is a cross-sectional structural diagram of the main part of the optical fiber ferrule 9, and FIG. FIG. 4 is a schematic view of the main parts of a conventional optical fiber ferrule end face polishing apparatus for polishing the ferrule end face into a spherical shape. FIG. (Main reference numbers) 1. Ferrule, 2. Optical fiber, 3. Adhesive, 4. Ferrule holder, 5. Screw tightening, 6. Polishing surface plate, 7. Spherical bearing. , 11... Driven friction wheel, 12... Idler rotating wheel, 13... Spring for pressing, 14... Driving friction wheel, 16...
- Eccentric rotating friction wheel, 61... Polishing agent supply nozzle, 110... Ferrule end face, 120... Ferrule through hole

Claims (14)

[Claims] (1) A device for polishing the end surface of a ferrule into which an optical fiber is inserted and fixed into a spherical shape, comprising a polishing means having a polishing surface, and a means for holding the ferrule so that the end surface of the ferrule is pressed against the polishing surface. and,
driving means for driving the holding means to rotate the ferrule about its axis and swinging about an axis perpendicular to the axis; the holding means presses the ferrule end face against the polished surface; An optical fiber ferrule end face polishing apparatus characterized in that the end face of the ferrule is polished into a convex spherical shape by rotating and swinging the ferrule. (2) The driving means includes a rotation mechanism that rotates the holding means, a gripping means that swingably grips the holding means, and a swinging movement using the gripping portion as a fulcrum by driving the holding means. The polishing apparatus according to claim 1, further comprising a swinging mechanism for causing the polishing apparatus to rotate. (3) The rotation mechanism includes a first friction wheel mounted coaxially with the holding means, a second friction wheel that presses against the first friction wheel, and rotates the shaft of the second friction wheel. 3. The polishing apparatus according to claim 2, further comprising driving means. (4) The shaft of the second friction wheel is swingably supported, and the rocking mechanism includes a third friction wheel coaxially and rotatably mounted on the shaft of the second friction wheel. an eccentric rotating friction wheel that engages with the third friction wheel and rotates on a fixed shaft; means for rotationally driving the eccentric rotating friction wheel; The present invention is characterized in that it includes a pressing means for pressing the first friction wheel and the second friction wheel against each other and pressing the third friction wheel and the eccentric rotating friction wheel against each other. The polishing device according to scope 3. (5) The pressing means includes an idler rotating ring and a spring means that urges the idler rotating ring to press the idler rotating ring against the first friction wheel. polishing equipment. (6) Claims 2 to 5, wherein the gripping means includes a spherical bearing that grips the holding means, and a spherical bearing support section that supports the spherical bearing.
The polishing device according to any one of the above items. (7) The spherical bearing support section includes a slide shaft, a support that supports the spherical bearing and is movable along the slide shaft, and an adjustment screw that drives the support along the slide shaft. 7. The polishing apparatus according to claim 6, further comprising: (8) The swinging mechanism includes a friction wheel mounted coaxially with the holding means, an eccentric rotating friction wheel that presses against the friction wheel, means for rotationally driving the shaft of the eccentric rotating friction wheel, and 3. The polishing apparatus according to claim 2, further comprising means for urging a wheel to press the wheel against the eccentric rotating friction wheel. (9) The polishing device according to claim 8, wherein the pressing means comprises an idler rotating ring and a spring means that urges the idler rotating ring to press it against the friction wheel. . (10) The polishing apparatus according to any one of claims 1 to 9, wherein the holding means is a chuck that grips the ferrule. (11) The holding means includes a chuck that grips the ferrule, and a support member that rotatably supports the chuck, and the rotation mechanism is supported by the support member and rotates the ferrule. A polishing device according to any one of claims 2 to 9, characterized in that the polishing device is a motor. (12) The polishing device according to any one of claims 1 to 10, wherein the polishing surface has a concave spherical shape. (13) The polishing means comprises a tiltable polishing surface plate having a concave spherical annular polishing zone, and means for rotationally driving the surface plate.
The polishing device according to any one of the above items. (14) The driving means includes a first friction wheel mounted coaxially with the holding means, and a second friction wheel fixed to a swingable rotating shaft and pressed against the first friction wheel; a third friction wheel rotatably mounted on the rotating shaft of the second friction wheel; and an eccentric rotating friction wheel rotatable about a fixed shaft and engaged with the third friction wheel. , the first friction wheel is biased by a spring means so as to cause frictional engagement between the first friction wheel and the second friction wheel and between the third friction wheel and the eccentric rotating friction wheel. 2. The polishing apparatus according to claim 1, further comprising: an idler rotating ring that presses against the holding means; a spherical bearing that grips the holding means; and a spherical bearing support that supports the spherical bearing.