JPWO1994009944A1 - Edge polishing machine - Google Patents

Abstract

(57) [Abstract] This publication contains application data prior to electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] End-Face Polishing Machine Technical Field The present invention relates to a polishing machine for polishing the tip of a ferrule, to which an optical fiber is attached, into an optical fine (including end face) convex spherical surface.

Background Technology In ultra-high-speed communications using laser diodes, reflections at the fiber end face of an optical connector increase noise and signal quality. To reduce reflections at the end face, a widely used technology is PC (Physical Contact) end face formation, in which the ferrule end face is machined into a convex spherical shape centered on the fiber, allowing the end faces to be spaced apart without any air gaps when connected.

To achieve this convex spherical surface, a polishing plate is formed by attaching a polishing sheet to the top surface of a flat plate made of a soft, elastic material. The end face of the ferrule to be polished is pressed against the polishing plate, which moves along an arc. During this process, the polishing plate elastically deforms and bends, and this bending phenomenon is used to simultaneously and accurately form a convex spherical surface on both the ferrule and the fiber end face.

On the other hand, the motion mechanism of the sample and polishing plate has a significant impact on the finish accuracy of the end face and the polishing time. Therefore, the polishing plate uses a ramp mechanism, a well-known machine for polishing parallel workpieces. That is, the workpiece (ferrule) is kept stationary, and the polishing plate is rotated and revolved simultaneously by a planetary gear and a drive motor, causing the ferrule to abut against the polishing plate, creating a rough-and-bent motion that traces a uniform trajectory.

As a result, the ferrule has a convex spherical shape with the desired fiber at its apex, and can be efficiently processed at the same time.

As a prior art example, US Patent No. 49793340, "Practical Fiber End-Facing Polishing Devrce M, Takahashi, December 25, 1990," discloses a mechanism that has an eccentric disk that rotates concentrically with a rotating disk, and a tIX gear that transmits the rotation of a revolution motor to this eccentric disk. This gear is then coupled to the polishing disk, causing the polishing disk to rotate and revolve.

Because the revolution mechanism uses planetary gears, even when the revolution motor is stopped, the planetary gears continue to rotate while meshing with the stopped revolution motor gear when rotation is applied to the rotation shaft, resulting in the grinding disc revolving. This creates limitations on setting the optimal rotation and revolution speeds for polishing conditions such as finishing accuracy and processing time.

Furthermore, the multiple workpieces 133 fixed to the support plate must be precisely perpendicularly abutted against the polishing plate to obtain a convex spherical surface with the desired fiber at the apex. However, in Figure 6, the support plate 131 on which the sample is placed is fixed to the support stage A via the pressure contact member S. This inevitably results in a perpendicular centering error due to the fit between the pressure contact member S and the support plate 131 and the screw fastening 136, resulting in the ferrule being abutted at an angle.

As a result, the finished surface of the ferrule deviates slightly from the ideal convex spherical surface with its apex at the center of the fiber, which significantly affects the connector connection performance.

Therefore, the object of the present invention is to solve the above-mentioned problems of the prior art by providing a polishing machine in which the rotational and revolution speeds of the polishing disc can be set independently, and by introducing a mechanism that allows the workpiece to be accurately brought into contact with the polishing disc.

Disclosure of the Invention In this invention, the same processing pressure is constantly applied to each of the ferrule end faces of multiple polishing samples. The polishing plate is made of a soft material and is attached to an abrasive sheet. The polishing plate is equipped with a motion mechanism that can independently rotate and revolve. This causes the polishing plate to elastically deform and bend. By employing this bending phenomenon and a lapping motion in which the sample traces a uniform trajectory, each sample is polished to a convex spherical surface with a fine point at its apex.

Specifically, the multiple end face polishing machine is equipped with multiple single units, each consisting of a fixture plate for fixing rod-shaped components such as multiple ferrules with attached fibers, a support mechanism for supporting the fixture plate and orthogonally abutting the rod-shaped components against the polishing plate, and a polishing plate equipped with a polishing member for polishing the rod-shaped components. The machine is equipped with a drive mechanism for independently rotating and revolving the polishing plates, and the ferrule fixtures are processed using a pin-point bearing mechanism, modeled after a polishing plate with pre-set flatness, to precisely orthogonally abut the multiple ferrules against the polishing plate.

By using the above methods, it has become possible to further improve the polishing finish performance and mass-produce a polishing machine that can process convex spherical surfaces using a simple method.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to Figures 1 through 5, which illustrate a single-throat end face grinder.

Figure 1 is a plan view of the present invention, and Figure 2 is a cross-sectional view of the present invention. A first rotation transmission disk 2, which is rotated about its axis by a rotation motor 1, is fixed to the shaft of the motor 1. Furthermore, multiple first pins 3 are fixed concentrically to the rotation axis of the first rotation transmission disk 2. Rotation transmission disks 4, which are rotatably inserted onto the first pins 3, each have holes at the same eccentric position. Second pins 5, which are rotatably inserted to correspond to the holes, are fixed to a second rotation transmission disk 6.

Meanwhile, a revolution transmission shaft 11 is provided at the center of the rotation axis via a pair of gears 8 and 9 rotated by a revolution motor 7, with a bearing cylinder 10 as a guide. The revolution transmission shaft 11 is provided with a support hole 12 that penetrates the shaft at a position eccentric from the center of rotation by the same amount as the rotation transmission disk. A rotation shaft 13 is rotatably inserted into the support hole 12, with one end fixed to the second rotation transmission disk 6 and the other end connected to a polishing disk 15 via a connecting member 14.

Furthermore, a polishing member (not shown) is provided in the polishing face 115, and a rod-shaped member 16, such as a ferrule, whose end face is to be polished, is in contact with the polishing member. The rod-shaped member 16 is detachably fixed to a multiple fixture plate 17, and a pressure shaft 19 presses the fixture plate 17 against the polishing face with a predetermined force. The fixture plate 17 is prevented from rotating by a rotation stopper 20.

Multiple weights are provided to allow any desired weight to be applied to the support mechanism (not shown).

Next, the operation of this invention will be described. FIG. 3 is a plan view illustrating the invention in detail, and FIG. 4 is a cross-sectional view taken along the line A-A' in FIG. 3. First, regarding revolution, the revolution motor 7 rotates the revolution transmission shaft 11 about the Y axis via a set of gears 8 and 9. At this time, the center of the polishing disk 15 is on the Y' axis, offset by e2 from the Y axis, so the Y' axis moves with a radius of e about the Y axis. At this time, the rotation shaft 13 exists within the revolution transmission shaft 11, but as shown in FIG. 3, the rotation transmission disk 4 is disposed with an eccentricity e1 identical to the eccentricity e2 of the Y and Y' axes. Therefore, the rotation transmission disk 4 rotates around the first pin 3 in the same phase as the rotation of the revolution transmission shaft 11. Therefore, whether the first rotation transmission disk 2 is stationary or rotating, the rotation of the revolution transmission shaft 11 is not restricted.

Meanwhile, for rotation, the first rotation transmission disk 2 is rotated by the rotation motor 1, and since the first pin 3 is concentric with the rotation transmission disk 2, it follows the same trajectory around the Y axis. The rotation axis of the rotation shaft 13 is offset by 82 from the first rotation transmission axis, but since the second pin 5, which is concentric with the second rotation transmission disk 6, is connected via the rotation transmission disk 4 while maintaining the eccentricity e1, the same rotation speed as the first rotation transmission disk 2 is transmitted to the rotation shaft 13.

For the purposes of this invention, the rotational speed is set much slower than the revolutional speed. However, as mentioned above, the rotational speed and revolutional speed can be set independently and are not subject to any limitations. Figure 5 shows an example of the trajectory left by the rod-shaped member 16 on the polishing disc 15, demonstrating the efficient use of the polishing member.

Next, we will discuss the eccentricity of curvature of the convex spherical surface, which is the most important factor in the accuracy of polished surfaces.

As shown in FIGS. 1 and 2, the fixture plate 17, which holds multiple ferrules 16, has a tapered hole 31 at its center that engages with the pressure-applying retainer shaft 19. This eliminates the problem of parallelism between the polishing plate and the ferrule support member 18, an unavoidable mechanical imperfection that occurs when assembling a polishing machine.

Furthermore, when multiple abrasives (ferrules) of different lengths are attached to the support 17, they come into contact with the grinding disc at uneven lengths. In this case, the above-mentioned bimbipaddle/board coupling system acts to absorb the grinding motion caused by the uneven lengths.

In addition, all of the multiple workpieces mounted on the fixture platen 17 are positioned at equal distances from the center of the fixture platen 17. As a result, the multiple workpieces move along the same path during the final finishing process, resulting in a uniform finish.

It goes without saying that a multiple end face polisher, which has multiple units with the functions of the multiple polisher described above, installed in the same plane, is also effective for polishing multiple workpieces.

BRIEF DESCRIPTION OF THE DRAWINGS (1) 1 is a plan view of the present invention; (2) 2 is a cross-sectional view of the present invention.

FIG. 3 is a plan view for explaining the present invention in detail. FIG. 4 is a cross-sectional view taken along line VIII-A' in FIG. 3. FIG. 5 shows an example of the track left by a rod-shaped member on a polishing disc. FIG. 6 shows the prior art.

INDUSTRIAL APPLICABILITY The main focus of this invention is a high-precision, mass-produced polishing machine for finishing the end faces of ferrules into a convex spherical surface with the fiber at the apex.

The key feature of this invention is that multiple ferrule end faces, which are polished specimens, are constantly held stationary and pressed against a polishing plate with a soft material and an abrasive sheet attached. A motion mechanism allows the polishing plate to revolve and rotate independently, resulting in a ramping motion that causes the specimens to trace a uniform trajectory on the polishing plate, enabling multiple specimens to be polished into convex spherical surfaces with the desired fiber at the apex. Furthermore, for mass production, multi-unit end face polishing machines are often configured with multiple units. This allows for simultaneous processing of the same process in multiple units, or the ability to assign each process, such as polishing, finishing, and polishing, to a dedicated unit for each process, resulting in significant improvements. Naturally, the selection of the radius of curvature is dependent on the use of a soft, elastic material with optimal hardness, and the angle f1 of the ferrule end face. It is obvious that forming a convex spherical surface on a flat surface can be achieved by presetting the ferrule attachment angle of the ferrule support member to the desired angle. The end face polishing machine of this invention is ideal for forming a convex spherical surface on a ferrule with a fixed fiber, and its industrial value is great.

Claims (7)

[Claims] 1. An end face polishing machine comprising a fixture plate for fixing a rod-shaped member, a support mechanism for supporting the fixture plate and vertically abutting the rod-shaped member against the polishing plate, a polishing plate provided with a polishing member for polishing the rod-shaped member, and a drive mechanism for independently rotating and revolving the polishing plate. 2. An end face polishing machine according to claim 1, characterized in that the drive mechanism comprises a rotation motor, a revolution motor, a first rotation transmission disk rotated about its axis by the rotation motor, a plurality of rotation transmission disks rotatably inserted onto a plurality of first pins fixed concentrically to the rotation center axis of the first rotation transmission disk and each having holes at the same eccentric position, a second rotation transmission disk having second pins fixed concentrically to correspond to the holes in the rotation transmission disk, a revolution transmission shaft revolved about the rotation axis center by the revolution motor using a bearing sleeve as a guide and having a support hole passing through it at a position eccentric from the center of rotation by the same amount of eccentricity as the rotation transmission disk, and a rotation shaft fixed at one end to the second rotation transmission disk, with its center rotatably inserted into the support hole of the revolution transmission shaft and its other end connected to the polishing disk. 3. An end face polishing machine according to claim 1, characterized in that the fixture plate is capable of fixing a plurality of rod-shaped members arranged at equal distances from the center thereof. 4. The end face polishing machine according to claim 1, wherein the support mechanism is characterized in that a plurality of ferrules are brought into contact with the polishing disc by a combination of a ferrule fixing jig disc having a tapered hole in the center and a presser shaft that engages with the jig disc. 5. The end surface grinder according to claim 4, wherein at least a portion of the tip of the presser shaft is tapered. 6. The end face polishing machine according to claim 1, wherein the support mechanism is provided with a plurality of weights so that a predetermined load is applied to the ferrule. 7. The end surface polishing machine according to any one of claims 1 to 6, wherein the end surface polishing machine is regarded as one unit and a plurality of units are arranged in a multi-unit configuration.