JP3929659B2 - End polishing machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microworkpiece end surface polishing pressure device for polishing a microworkpiece end surface, and more particularly to an end surface polishing device for polishing an end surface of a ferrule which is a connector component of an optical fiber into a spherical shape. About.
[0002]
[Prior art]
In recent years, optical communication is expected as a next-generation communication technology because of its large capacity and high speed, and optical fibers are gradually being introduced to our daily lives. In the ferrule, a zirconia ceramic material is formed into a cylindrical shape by an injection molding method, an extrusion molding method or a press molding method, and is used as a main optical connector part of an optical fiber. Here, the hollow part of the ferrule is referred to as a fiber insertion hole, and an optical fiber is inserted, and the optical fibers are connected by abutting the end faces of the ferrules. When connecting an optical fiber, it is necessary to polish the end surface of the ferrule into a spherical shape with extremely high surface roughness accuracy in order to prevent reflection loss of light at the end face butting surface of the ferrule and to keep the optical characteristics of the optical fiber good. .
[0003]
Conventionally, when polishing the end face of a ferrule, after fixing the ferrule to a jig board, the end face of the ferrule is pressed against a polishing sheet that is elastically deformed with a constant pressure (load, spring force), and the polishing sheet is rotated to rotate the ferrule. By utilizing the spherical concave surface of the polishing sheet generated by pressing the end face, the end face of the ferrule was polished into a spherical shape in three stages of rough finishing, intermediate finishing and dense finishing.
[0004]
[Problems to be solved by the invention]
In the conventional polishing apparatus, when polishing the end face of the ferrule, there is no means for controlling the pressing pressure of the ferrule end face, and as a result, the end face of the ferrule is pressed against the polishing sheet with high pressure to polish it into a spherical shape, A high pressing force at the start of polishing becomes a burden on the end surface of the ferrule, and there is a problem that the end surface of the ferrule is deeply scratched.
[0005]
The present invention has been made in view of the above-described problems, and the object of the present invention is to enable control of the pressing pressure of the ferrule end face against the polishing sheet, particularly to the ferrule end face at the start of polishing. It is an object of the present invention to provide an end surface polishing apparatus that can prevent the occurrence of scratches on the end surface of the ferrule by setting the pressing pressure of the ferrule to a low level. The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, an end surface polishing apparatus according to the present invention includes a lever for connecting a jig board for fixing a micro-workpiece to one end , a lower spring for supporting the lever by pushing it up from below, and the lever of the lever. A pressure sensor disposed on an upper portion facing the lower spring and configured to detect a pressure for pressurizing the jig board; a pressure head disposed such that a lower end thereof is in contact with an upper surface of the pressure sensor; and the pressure head is the arrangement the the lower spring coaxially on top, and an upper spring that presses the pressing head, a pressing for pressing the end face on the polishing sheet to lower the pre-Symbol lever the fine workpiece; the And a pressurizing control unit that controls a pressing pressure of the microworkpiece against the polishing sheet by the pressurizing unit.
[0007]
Further, the pressurizing unit detects and detects a motor that pressurizes a minute workpiece, a screw that lowers the lever by the rotation of the motor, and a pressing pressure of the end surface of the minute workpiece to the polishing sheet. A pressure sensor for feeding back the pressing pressure to the pressurizing control unit, and the pressurizing control unit is configured to apply the end surface of the microworkpiece to the polishing sheet based on the fed back pressing pressure. It is characterized by controlling the pressing pressure.
[0008]
Further, the pressurizing control unit outputs a pressure setting pressure signal for pressing the end surface of the microworkpiece to the polishing sheet, a pressure setting pressure signal from the memory device, and a pressure pressure from the pressure sensor. A comparator for comparing a detection signal and calculating a difference between the pressing setting pressure signal and the pressing pressure detection signal; and according to a difference between the pressing setting pressure signal and the pressing pressure detection signal, A pressure corrector for correcting the pressing pressure of the end surface of the micro-workpiece on the polishing sheet, and driving the motor so that the pressing pressure of the end surface of the micro-workpiece on the polishing sheet becomes the pressing pressure corrected by the correcting device. It is characterized by having a pressure driver.
[0009]
Furthermore, the micro workpiece is a ferrule that is a connector component of an optical fiber.
Therefore, in the present invention, after a micro workpiece such as a ferrule is fixed to the jig board, the jig board is installed on the lever, and the lever is lowered by the rotation of the motor, so that the end surface of the micro workpiece is placed on the polishing sheet. It is pressed at a predetermined pressure.
[0010]
At that time, the pressure sensor detects the pressing pressure of the end surface of the minute workpiece against the polishing sheet, and the comparator compares the pressing pressure signal stored in the setting pressure storage device with the pressing pressure detection signal from the pressure sensor. The difference between the pressing set pressure signal and the pressing pressure detection signal is calculated.
Then, in the corrector, the pressing pressure of the end surface of the micro workpiece on the polishing sheet is corrected according to the difference between the pressing set pressure signal and the pressing pressure detection signal, and the end surface of the micro workpiece on the polishing sheet is corrected by the driver. The motor is driven so that the pressing pressure becomes the pressing pressure corrected by the corrector, and the end surface of the minute workpiece is polished into a spherical shape by rotating the polishing sheet.
[0011]
As described above, according to the present invention, it is possible to control the pressing pressure of the end face of the micro workpiece to the polishing sheet. In particular, if the pressing pressure to the end face of the micro workpiece at the start of polishing is set low, Generation of scratches on the end face of the object is prevented.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, a lever connected to a jig board for fixing a micro workpiece, a pressurizing unit that lowers the lever and presses an end surface of the microworkpiece onto a polishing sheet, and the micromachine by the pressurizing unit. An end surface polishing apparatus including a pressurization control unit that controls a pressing force of an object to the polishing sheet was configured. As a result, the pressure was controlled to be constant, the polishing state was kept constant, and polishing with little variation in the finished state became possible.
[0013]
Further, the pressure unit measures a lower spring that supports the lever, a pressure head that presses the lever, an upper spring that presses the pressure head, and a pressure between the pressure head and the lever. A pressure sensor was added. Then, the weight of the lever is canceled by the lower spring and the upper spring. As a result, only the polishing pressure applied to the end of the minute workpiece can be detected, and for example, the polishing pressure can be controlled regardless of the weight of the ferrule or jig.
[0014]
Furthermore, the pressurization control unit stores a pressure value to be pressurized, a comparator that compares the pressure value stored in the storage device with an output value from the pressure sensor, and an output of the comparator A corrector that corrects the pressing pressure by a signal and a driver that applies drive power to a motor that drives the lever from an output signal of the corrector are added. As a result, the pressure can be controlled so that the optimum polishing pressure value is set in advance.
[0015]
And the said memory | storage device can each set the pressure suitable for each step of rough finishing, intermediate finishing, and dense finishing by memorize | storing a some pressure setting value by polishing conditions.
And an input means connected to the storage device for inputting one or more values of the type of abrasive, the particle size of the abrasive, the material of the ferrule, the tip shape of the ferrule, and the diameter of the ferrule; By providing a calculation unit that calculates the target pressure from the input value and stores it in the storage device, optimum conditions corresponding to various polishing conditions can be easily set.
[0016]
Further, since the linear guide is provided as a guide for lowering the lever, there is no shaking around the axis of the lever, and a vertical load can be correctly applied, for example, the eccentricity of the ferrule end face is eliminated.
Further, polishing is performed with the end of the optical fiber exposed from the end of the ferrule, and the ferrule polishing method increases the polishing load when the end of the optical fiber and the end of the ferrule are substantially flush with each other. By using this, it is possible to prevent the end portion of the optical fiber from being broken or hooked.
[0017]
Further, the end surface of the ferrule into which the optical fiber is inserted is polished at a first pressure, and then polished at a second pressure higher than the first pressure after a predetermined time has passed, so that the optical fiber is broken at high speed. Polishing that does not occur is possible.
Finally, the end surface of the ferrule is pressed against the polishing sheet by driving the motor, and the polishing state of the ferrule is detected from the current or voltage of the motor. Accordingly, it is possible to determine an abnormality during polishing without stopping the apparatus and observing the end face. When an abnormality occurs, it is possible to lower the polishing pressure and decrease the polishing speed, and wait for the state to recover.
[0018]
The above-described embodiment has an effect individually, but the effect is further enhanced by combining the embodiments.
[0019]
【Example】
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 is a front view of an end surface polishing apparatus according to an embodiment of the present invention, FIG. 2 is a side view of the end surface polishing apparatus according to an embodiment of the present invention, and FIG. 3 is an embodiment of the present invention. Fig. 4 is a plan view showing a state in which a ferrule is fixed to a jig board of the end surface polishing apparatus according to the embodiment, and Fig. 4 is a block diagram of a pressure control unit of the end surface polishing apparatus according to the embodiment of the present invention.
[0020]
In FIG. 1, a polishing sheet 70 that is elastically deformed is disposed on the upper surface of a polishing surface plate 60 that moves by one or a combination of rotation, revolution, and oscillation. Next, a jig board 50 for detachably fixing the ferrule W at both ends is arranged on the upper part of the polishing sheet 70 so that the end face of the ferrule W is in contact with the surface of the polishing sheet 70. Here, the jig board 50 is connected to one end of the lever 10 and pressed downward, and the end surface of the ferrule 5 is pressed to the polishing sheet.
[0021]
Next, a lower spring 24 that pushes up the lever 10 from below is disposed in the vicinity of the end opposite to the end connected to the jig board 50 of the lever 10. And the pressure sensor 23 for detecting the pressure which pressurizes the jig board 50 is arrange | positioned in the upper part of the position facing the lower spring 24 of the lever 10. FIG. Here, a load cell is used as the pressure sensor.
[0022]
Then, the pressure sensor 23 is disposed so that the lower end of the pressure head is in contact with the upper surface of the pressure sensor 23, and the upper spring 22 that presses the pressure head 21 is disposed above the pressure head 21. In the present invention, the upper surface and the lower surface of the lever 10 are compressed by the lower spring 24 and the upper spring 22, respectively, so that the load combining the lever 10 or the lever 10 and the jig board 50 is canceled by the lower spring 24. Can take zero balance. As a result, only the load applied from the upper part of the lever 10 can be detected by the pressure sensor 23. Therefore, the polishing load can be accurately detected even if the types of the lever 10 and the jig board 50 and the types and the number of the ferrules 5 are changed.
[0023]
In the drawing, the lever 10, the upper spring 22, the pressure head 21, the pressure sensor 23, and the lower spring constitute a part of the pressure unit 20. Next, the pressurizing part 20 is shown in FIG.
The pressure unit 20 has a mechanism for moving the lever 10 up and down. The lever 10 is connected to a pressure head 24 via a pressure sensor 23 for detecting pressure, and is pressurized by rotation of a screw 26. The head 21 and the lever 10 move up and down. Then, it acts to transmit the force for pressurizing the lever 10 to the jig panel 50.
[0024]
In addition, the lever 10 is provided with a guide 28 so as to accurately move up and down. As the guide 28, a linear guide arranged in parallel with the axis of the upper spring 22 or the lower spring 24 is used. As a result, the pressure due to the lateral shaking of the lever 10 is not detected, and the S / N ratio can be improved.
The screw 26 rotates by transmitting the rotation of the motor 25 through the shaft 25a, the pulley 27a, the belt 29, and the pulley 27b. Then, the lever 10 is moved up and down. The load applied by the rotation of the motor 25 is detected by the pressure sensor 23, and the pressurization control unit 40 supplies electric power for driving the motor 25 to constitute a pressurization control circuit.
[0025]
FIG. 3 is a diagram illustrating the pressurization control unit 40. The detection output of the pressure sensor 23 is input, and the value stored in the storage device 42 that stores the pressure value is compared by the comparator 41. Then, data for correcting the pressure based on the difference from the target pressure is created by the corrector 43, the output is input to the driver 44, and the power for driving the motor 25 is output.
[0026]
In FIG. 3, the configuration of the comparator 41 and the corrector 43 is shown. However, the output of the pressure sensor 23 is converted by an A / D converter, and a control program and a set pressure are stored. It is possible to use a CPU for comparing and calculating preset pressure values and obtaining output data for driving the motor 25, and a system for converting the output of the CPU by a D / A converter.
[0027]
According to the present invention, the pressure applied to the ferrule end can be controlled to be a predetermined set value, and as a result, the load applied to the ferrule end during polishing can be made constant.
Furthermore, in the initial polishing state of the ferrule, when the end of the optical fiber is exposed from the end of the ferrule, the load is reduced, and the end surface of the optical fiber and the end surface of the ferrule are almost flush with each other. Where no chipping occurs, the polishing load can be increased and polishing can be performed at high speed. Here, the load can be switched by a method of specifying with a timer inside the pressurization control unit 40 or a method of calculating the value of the real time clock. Further, the current of the motor 25 and the current of the motor that drives the polishing platen 60 are detected, and the polishing of the ferrule end is started from the motor driving load, that is, the initial polishing of the optical fiber end is completed, and the ferrule is finished. It is also possible to detect a state that is in the same plane.
[0028]
As another polishing state detection method, the contact state of the ferrule end with the polishing sheet 70 is determined from the relationship between the drive amount of the screw 26 and the pressure change from the relationship between the drive of the motor 25 and the output of the pressure sensor 23. be able to. By this method, the detection of the point where the end face of the optical fiber coincides with the end face of the ferrule, the occurrence of cracking or chipping of the optical fiber, and if a pressure value higher than the specified value is detected, it is judged as abnormal. It is possible to stop the operation of the polishing apparatus and reduce the waste time due to polishing of defective products.
[0029]
Further, the pressure value related to the polishing load to be set is large at the time of rough finishing, and can be lowered as the intermediate finishing and dense finishing steps progress to improve the polishing rate and prevent the occurrence of polishing flaws.
In addition to this, it is possible to change the pressure to be set depending on the type of abrasive, abrasive particle size, ferrule material, ferrule tip shape, and ferrule diameter. You can choose.
[0030]
FIG. 4 is a view showing a jig board 50 according to the present invention, in which two ferrules 5 are sandwiched and fixed on each side of the hexagon by a fixing block 51.
As described above, according to the end surface polishing apparatus of the present embodiment, the pressing pressure of the end surface of the ferrule W to the polishing sheet 70 can be controlled, and the pressing pressure to the end surface of the ferrule W at the start of polishing can be set low. Thus, it is possible to prevent the end face of the ferrule W from being damaged.
[0031]
【The invention's effect】
As can be understood from the above description, the end surface polishing apparatus of the present invention is provided with a pressurization control unit that controls the pressing pressure of the end surface of the microworkpiece to the polishing sheet, thereby polishing the endface of the microworkpiece. It is possible to control the pressing pressure on the sheet, and in particular, it is possible to set the pressing pressure on the end face of the micro-workpiece at the start of polishing low, so that it is possible to prevent the occurrence of scratches on the end face of the micro-workpiece. In addition, the precision of end face polishing can be improved by changing the pressing force to the end face of the micro work according to the material strength of the micro work and the polishing steps of rough finish, intermediate finish and dense finish.
[Brief description of the drawings]
FIG. 1 is a front view of an end surface polishing apparatus according to an embodiment of the present invention.
FIG. 2 is a side view of an end surface polishing apparatus according to an embodiment of the present invention.
FIG. 3 is a block diagram of a pressure control unit of the end surface polishing apparatus according to the embodiment of the present invention.
FIG. 4 is a plan view showing a state in which a ferrule is fixed to a jig board of an end surface polishing apparatus according to an embodiment of the present invention.
[Explanation of symbols]
5 Ferrule 10 Lever 20 Pressure unit 21 Pressure head 22 Upper spring 23 Pressure sensor 24 Lower spring 25 Motor 25a Shaft 26 Screw 27a, b Pulley 28 Guide 29 Belt 40 Pressure control unit 41 Comparator 42 Storage device 43 Corrector 44 Driver 50 Jig plate 51 Fixed block 60 Polishing surface plate 70 Polishing sheet

Claims (6)

A lever for connecting a jig plate for fixing a micro-workpiece to one end , a lower spring for supporting the lever by pushing it from below, and an upper portion of the lever facing the lower spring, pressurizing the jig plate A pressure sensor for detecting pressure; a pressure head disposed such that a lower end thereof is in contact with an upper surface of the pressure sensor; and a pressure head disposed above the pressure head and coaxially with the lower spring, It includes an upper spring for pressing, and the, a pressing for pressing the end face of the small workpiece is lowered to pre-Symbol lever on the polishing sheet;
A pressurization control unit that controls a pressing pressure of the microworkpiece against the polishing sheet by the pressurization unit;
An end face polishing apparatus comprising: Cancel the more the lever or the lever and weight to suit the jig plate to the lower bar ne, end face polishing apparatus according to claim 1, wherein that preparative zero balance. A storage device for storing a pressure value to be pressurized by the pressurization control unit;
A comparator that compares the pressure value stored in the storage device with the output value from the pressure sensor;
A corrector that corrects the pressing pressure according to an output signal of the comparator;
The end surface polishing apparatus according to claim 1, comprising a driver that applies driving power to a motor that drives the lever from an output signal of the corrector. The end surface polishing apparatus according to claim 3 , wherein the storage device stores a plurality of pressure setting values according to polishing conditions. An input means connected to the storage device for inputting one or more values of the type of abrasive, the particle size of the abrasive, the material of the ferrule, the tip shape of the ferrule, and the diameter of the ferrule; and the input The end surface polishing apparatus according to claim 3 or 4, further comprising a calculation unit that calculates a target pressure from a value input by the means and stores the calculated pressure in the storage device.   The end surface polishing apparatus according to claim 1, further comprising a linear guide as a guide for lowering the lever.

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