JP2006065161A - Ferrule chamfering apparatus and ferrule processing method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a conventional problem in processing the chamfered part of a ferrule, a problem of a short life of a tool because of a load on the tool as cutting proceeds. <P>SOLUTION: This is an apparatus for processing a chamfered part for guiding an optical fiber to the end of a through-hole 2 of a cylindrical body 1 that becomes a ferrule with the through-hole 2 in the axial direction. The apparatus is equipped with a holding part 10 for fixing or rotating the cylindrical body 1, a gimlet-shaped tool 20 for processing the chamfered part, and a driving part 30 for rotating the tool 20 while bringing it in contact with the opening face of the through-hole 2 of the cylindrical body 1 in the axial direction. The apparatus is characterized in that the cutting speed of the tool 20 is reduced as the contact area increases between the cylindrical body 1 and the tool 20. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an apparatus for processing a chamfered portion for guiding an optical fiber formed at an end portion of a through hole for inserting and holding an optical fiber in a ferrule for optical communication, and a processing method using the same.

  The optical fiber ferrule is known to be made of zirconia ceramics, has a through hole in the axial direction, and inserts and holds the optical fiber in the through hole.

As shown in the cross-sectional view of FIG. 2, the ferrule for optical communication has a funnel-shaped chamfered portion 42 for guiding an optical fiber at the end of a through hole 41 provided in the axial direction. When machining the portion 42, as shown in FIG. 3, a cylindrical body 1 having a through-hole 2 having a constant diameter in the axial direction is held by a chuck 51, and a pyramidal monolithic diamond is formed on the cylindrical body 1. While rotating the tool 20 and the cylindrical body 1 from the opening surface of the through-hole 2, the tool 20 is pressed, and the tool 20 is cut at the top until the opening end becomes a predetermined size at a constant cutting speed. 4 or a cylindrical body 1 having a through-hole 2 having a constant diameter in the axial direction as shown in FIG. 20 and the cylinder 1 Then, the tool 20 is pressed, the opening end is cut by a small amount at a constant cutting speed at the top, and then the tool 20 is once separated from the cylindrical body 1 and then cut by a small amount at a constant cutting speed again. A method of chamfering by using was used (see Patent Documents 1 and 2).
Japanese Patent Laid-Open No. 5-154749 Japanese Patent Laid-Open No. 9-80261

  However, in the conventional chamfering process, the tool 20 made of diamond is pressed against the through-hole of the cylindrical body 1 with a constant force from the start to the end of the process, so that the tool 20 is increased when the cutting amount of the tool 20 increases. The load applied to is increased and easily damaged. Moreover, when it was going to extend the lifetime of the tool 20, there existed a problem that processing time became long and manufacturing efficiency fell.

  In addition, when the pressing of the tool 20 is intermittent, since it is an intermittent process, a load is applied to the top of the tool 20 and the chipping is likely to occur. Had the problem.

  In view of the above problems, the ferrule chamfering processing apparatus of the present invention is a processing for processing a chamfered portion for guiding an optical fiber to an end portion of a through-hole of a cylindrical body that is a ferrule having a through-hole in the axial direction. A device for holding or rotating the cylindrical body, a cone-shaped tool for processing the chamfered portion, and abutting the tool in an axial direction from an opening surface of a through hole of the cylindrical body And a drive section for rotating the tool while rotating the tool, and the cutting speed of the tool is reduced as the contact area between the cylindrical body and the tool increases.

  The ferrule chamfering apparatus of the present invention includes a control unit that measures the load of the tool with a load converter and adjusts the cutting speed by keeping the load constant.

  Further, in the ferrule processing method using the ferrule chamfering apparatus of the present invention, the cylindrical body is fixed or rotated by a holding portion, the tip of the tool is brought into contact with the opening surface of the through hole, and the tool is rotated. However, it is characterized by chamfering by cutting while reducing the cutting speed after cutting with a constant cutting speed.

  According to the ferrule chamfering apparatus of the present invention and the ferrule processing method using the same, a holding part for fixing or rotating the cylindrical body, a conical tool for processing the chamfered part, and the tool A drive unit for rotating while abutting in the axial direction from the opening surface of the through hole of the cylindrical body, and by reducing the cutting speed of the tool as the contact area between the cylindrical body and the tool increases, The tool life is significantly improved because the tool is processed without burden. Therefore, the cost of chamfering can be reduced, and an inexpensive ferrule can be provided.

  The present invention relates to an apparatus for processing a chamfer for guiding an optical fiber formed at an end of a through hole for inserting and holding an optical fiber in a ferrule for optical communication, and a processing method using the same, for example, In order to obtain a long cylindrical body having a through hole with a fixed diameter of 2.5 mm in the axial direction and 0.125 mm in the axial direction, zirconia ceramics etc. are produced by extrusion molding, injection molding, press molding, etc. To do.

  Next, the end surface is ground by a surface grinder or the like, and a cylindrical body processed to a predetermined length such as 10.5 mm is manufactured.

  Next, a chamfer for guiding the optical fiber to the end portion of the through hole of the obtained cylindrical body is processed using a ferrule chamfering apparatus (hereinafter simply referred to as a chamfering apparatus) as shown in FIG. .

  The chamfering apparatus includes a holding unit 10 for fixing or rotating the cylindrical body 1, a pyramid or conical tool 20 for processing the chamfered part, and an opening of the through hole 2 of the cylindrical body 1. And a tool driving unit 30 for rotating while abutting in the axial direction from the surface.

  As shown in FIG. 1 (c), the holding portion 10 has a chuck structure that holds the outer peripheral portion of the cylindrical body 1 by tightening and holds the outer peripheral portion of the cylindrical body 1 so that the outer periphery of the cylindrical body 1 is in contact at three points. An adjustment screw 11a is preferably provided in the axial direction so that the tilt of the cylindrical body 1 in the axial direction can be adjusted. When the holding portion 10 is attached and fixed in the axial direction by the adjustment screw 11a, it is preferable. The fixing angle is adjusted with a screw. Similarly, it is preferable to have an adjustment screw 11b for adjusting the eccentricity of the cylindrical body 1, and an adjustment screw 11b for adjusting the center of rotation from the circumferential direction of the holding portion 10 is provided. When the cylindrical body 1 is fixed by a chuck and rotated, a driving source is provided and driven by a belt.

  Further, the tool 20 for chamfering is made of single stone diamond, a material made of super hard material, a surface of a main body made of super hard material is coated with diamond abrasive grains, etc., and its outer shape is the shape of the chamfered portion. Since it is reflected as it is, it has a conical shape or a pyramid shape having an inclination angle in accordance with the angle of the chamfered portion. The tool 20 is preferably made of a pyramidal monolithic diamond, can be processed with a pyramidal ridgeline as an edge, and is rotated at a high speed around the top of the monolithic diamond, and the cylindrical body 1 has a through hole 2. It is grinded by rotating around the shaft center.

  Note that at least the top portion of the tool 20 may be formed of monolithic diamond as described above, a material made of a super hard material, or a surface of a main body made of a super hard material covered with diamond abrasive grains.

  Here, the chamfering apparatus of the present invention is characterized in that the cutting speed of the tool 20 is reduced as the contact area between the cylindrical body 1 and the tool 20 increases.

  The cutting speed of the tool 20 is a speed at which the top of the tool 20 is brought into contact with the opening surface of the through hole 2 of the cylindrical body 1 to advance in the axial direction. This cutting speed is initially constant and the contact area is increased. Accordingly, the tool 20 is processed with no load by gradually reducing the tool 20, so that the life of the tool 20 can be greatly improved and highly accurate processing can be performed.

  The drive unit 30 is incorporated in a CNC lathe to move in the axial direction at a constant speed, and can be easily obtained by providing the drive unit 30 on the stage.

  The drive unit 30 for controlling the cutting speed of the tool 20 in this way is for fixing the tool 20 as shown in, for example, a partial top sectional view of FIG. 1A and a partial side sectional view of FIG. Further, a chuck 32 for attaching the tool 20 is provided at the tip of the spindle 31 arranged in the horizontal direction, and the chuck 32 is provided with a hole for attaching the tool 20. The tool 20 can be fixed together with the chuck 32 by being fitted into an attachment hole provided in the spindle 31. Further, the chuck 32 and the spindle 31 can be more firmly fixed because the outer peripheral surface and the inner peripheral surface are tapered.

  In order to rotate the tool 20, a pulley 34 for transmitting the rotational force from the drive source 33 is attached to the opposite side of the spindle 31, and the spindle 31 is covered with a bowl-shaped spindle case 35. . The spindle case 35 has air bearings 39 on both sides with the spindle 31 as the center, and fixes the air bearing shaft 36 to the outer frame in parallel with the spindle case 35. Thereby, when the spindle case 35 is slid in the horizontal direction, it can be moved without feeling resistance. Further, the thrust of the spindle 31 can be changed by adjusting the air fed into the air cylinder 37 with a regulator. Further, a sensor 38 is attached to the most distal portion of the moving range of the spindle case 35, and a driving source 33 for driving the spindle is provided above the spindle case 35.

  Further, an air cylinder 37 is used to control the cutting speed of the tool 20 by increasing the contact area with the cylindrical body 1, for example, by rotating the spindle 31 and supplying air to the air cylinder 37. The spindle case 35 advances in the axial direction and reaches the forefront, and the sensor 38 reacts. The cylindrical body 1 fixed to the lathe chuck is rotated, and the stage and the cylindrical body 1 are moved in the axial direction at a speed of about 20 to 300 mm / min. The air pressure is kept constant until the cut depth is 1/3 of the axial length of the chamfered portion to be machined, and the subsequent cut depth is reduced to about 3/4 to 1/2 of the initial stage. Lower the stage moving speed without changing the stage moving speed, and stop cutting when the cutting depth has advanced.

  During machining, the spindle case 35 is pushed back in the direction opposite to the cutting direction due to a decrease in air pressure, and machining is performed while reducing the load on the tool 20. In response to the return of the spindle case 35 to the sensor 38 position, the remaining cut 1/3 is processed in the same manner by further reducing the air pressure by about 3/4 to 1/2 of the air pressure.

  When the machining is completed, the spindle case 35 reaches the forefront again, so that the sensor 38 reacts, and the stage moves backward in response to this, and the machining is completed.

  Moreover, it is preferable that the rotation speed of the tool 20 is 3000-12000 rpm, the rotation of the cylindrical body 1 is 200-800 rpm, and both rotation directions are the same direction.

  The drive unit 30 adjusts the cutting speed of the tool 20 by adjusting the cutting speed of the tool 20 by adjusting the rotating spindle 31 supported by the air bearing 39 and the pressure of the rotating spindle 31 by the air cylinder 37. It is preferable to control.

  This uses the air bearing 39 to control the cutting speed of the tool 20 by finely adjusting the tool 20 by pressing the air cylinder 37 in addition to the drive unit 3 that moves at a constant speed. This is because the pressure of the cylinder 37 can be directly transmitted as the pressure of the tool 20 and the weight of the drive unit 30 is not affected, and the drive unit 30 can be moved with extremely low pressure and low friction. As a result, the cutting speed of the tool 20 is reduced by gradually reducing the pressure of the air cylinder 37 as the machining time elapses. Therefore, as the contact area between the cylindrical body 1 and the tool 20 increases, the tool Decrease the cutting speed of 20.

  Specifically, the pressure of the air cylinder 37 is reduced by supplying the air pressure to the air cylinder 37 while switching the set air pressure using a solenoid valve or the like. It is preferable that the air pressure can be switched in two or more stages. It is preferable that the processing pressure at the initial stage of processing is 0.2 to 0.4 MPa, and the final cutting pressure is 0.2 to 0.05 MPa. This is because when the processing pressure exceeds 0.4 MPa, the pressure of the air cylinder 37 becomes strong and the processing load increases. When the processing pressure is below 0.05 MPa, the drive unit 30 cannot be moved, so that the processing cannot be cut. .

  Furthermore, it is preferable to have a control unit that measures the load of the tool 20 with a load converter and adjusts the cutting speed by keeping the load constant.

  Thereby, in order not to give an excessive load to the tool 20, the load of the tool 20 is sent to the control unit by the load converter, and it is determined whether it is higher or lower than the set value. The speed at which the tool 20 is moved is changed by a motor that can vary the cutting speed according to a command from a control unit that adjusts the cutting speed so as to keep the load of the tool 20 constant. The set value is preferably in the range of 10 to 20N, and if it is less than 10N, the processing ability is reduced and much time is required. This is because if the load exceeds 20N, the load on the tool 20 increases, and the tool 20 may be broken and damaged.

  Examples of the present invention will be described below.

  First, zirconia ceramics is formed by an extrusion molding method, fired at a predetermined temperature, and then subjected to inner diameter processing, outer diameter processing, and length processing to obtain an outer diameter of 2.5 mm, an inner diameter of 0.125 mm, and a length of 10.5 mm. A cylindrical body 1 having a through hole in the axial direction was obtained.

  As an embodiment of the present invention, the machining apparatus shown in FIG. 1 is incorporated into a CNC lathe, the pressure of the tool is adjusted by adjusting the amount of air fed from the air cylinder, and the chamfered portion is machined while reducing the cutting speed of the tool. Went.

  The tool 20 was made of a tetragonal pyramid-shaped monolithic diamond having an inclination angle of 60 degrees, and the tool 20 was rotated in the same direction at 12000 rpm and the cylinder was rotated at 800 rpm.

  The moving speed of the stage is 200 mm / min, the air pressure is kept constant at 0.3 MPa from the position where the cylindrical body 1 and the tool 2 are in contact to the cutting depth of 0.4 mm which is 1/3 of the total cutting depth. The depth of cut is 0.4mm, the air pressure is set to 0.2MPa, the stage is moved at a constant speed, the cut is stopped when it advances by a certain depth of cut, and the spindle case 35 is returned to the sensor 38 position. The remaining depth of cut of 0.4 mm is processed with an air pressure of 0.1 MPa, and the sensor 38 reacts because the spindle case 35 reaches the sensor position at the tip, and the stage moves backward in response to this. The processing ends.

  Here, the pressure of the air cylinder 37 pressing the tool 20 was 0.3 MPa, 0.2 MPa, and 0.1 MPa, and the total depth of cut was 1.2 mm.

  Further, as a first conventional example, the chamfered portion was machined by a CNC lathe using the tool 20. That is, the tool 20 moves at a constant cutting speed of 200 mm / min integrally with the stage of the CNC lathe. The tool 20 is pressed from the opening surface of the through hole 2 while rotating the tool 20 and the cylindrical body 1, and the chamfering process is performed by cutting the tool 20 until the opening end reaches a predetermined size at a constant cutting speed at the top. It was.

  Further, as a second conventional example, the tool 20 is moved at a constant speed of 200 mm / min by a CNC lathe using the tool 20 as in the first conventional example, cut by 0.1 mm, and then the tool 20 is temporarily moved from the cylindrical body 1 to 0. The chamfering process was performed until a predetermined size was obtained by performing intermittent cutting of 0.1 mm at a constant cutting speed of 200 mm / min after the distance of 1 mm was released and returned to the amount of cutting again.

  Then, in order to process the chamfered portion of the cylindrical body by each processing method and check the tool life, measure how many chamfered portions can be processed with one tool, and use each processing method to measure five chamfered portions. The tool was processed.

  The result is shown in FIG. As shown in FIG. 5, in the processing method of the present invention, the tool life was an average of 5,088 tools, and the tool life could be greatly extended. As a result, the production efficiency is improved and the processing cost can be reduced.

  On the other hand, in the first conventional example, the tool life is 361 on average, and even the intermittent cutting in the second conventional example is 508, and the tool replacement frequency is high and the production efficiency does not increase.

(A) is the upper surface partial cross section which shows the ferrule chamfering processing apparatus of this invention, (b) is a side surface partial cross section, (c) is a fragmentary sectional view which shows a holding | maintenance part. It is sectional drawing which shows the ferrule for optical communications. It is a front view explaining the chamfering process of the through-hole of the conventional ferrule. It is a front view explaining the chamfering process of the through-hole of the conventional ferrule. It is the figure which compared the lifetime of the tool which chamfered using the ferrule chamfering apparatus of this invention, and the lifetime of the tool which chamfered by the conventional processing method.

Explanation of symbols

1: Cylindrical body 2: Through hole 10: Holding portion 11a, 11b: Adjustment screw 20: Tool 30: Drive portion 31: Spindle 32: Chuck 33: Drive source 34: Pulley 35: Spindle case 36: Air bearing shaft 37: Air Cylinder 38: Sensor 39: Air bearing 40: Ferrule 41: Through hole 42: Chamfer 51: Chuck

Claims (3)

A processing apparatus for processing a chamfered portion for guiding an optical fiber to an end portion of a through-hole of a cylindrical body serving as a ferrule having an axial through-hole, and holding for fixing or rotating the cylindrical body Part, a conical tool for processing the chamfered part, and a driving part for rotating the tool in an axial direction from the opening surface of the through hole of the cylindrical body, A ferrule chamfering apparatus characterized by decreasing the cutting speed of the tool as the contact area with the tool increases. The ferrule chamfering apparatus according to claim 1, further comprising a control unit that measures a load of the tool with a load converter and adjusts a cutting speed by keeping the load constant. 3. A ferrule processing method using the ferrule chamfering apparatus according to claim 1 or 2, wherein the cylindrical body is fixed or rotated by a holding portion, and the tip of the tool is brought into contact with the opening surface of the through hole. A ferrule processing method comprising: cutting a tool at a constant cutting speed while rotating the tool, and then chamfering by cutting the tool while reducing the cutting speed.

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