JP4084908B2 - Hot plate heater for optical fiber termination - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hot plate heater for melting and terminating an end surface of a plastic optical fiber, and more particularly to a hot plate heater for optical fiber termination in which an electric heating element for heating a hot plate can be easily replaced.
[0002]
[Prior art]
A plastic optical fiber (hereinafter simply referred to as “optical fiber”) is a fiber made of a fiber such as methacrylic resin and coated with a fluorinated methacrylic resin having a refractive index lower than that of the core material. It is widely used in the field of optical transmission such as communication and light guide.
When this type of optical fiber is applied to optical communication or the like, if the finish of the end face is rough, it causes a coupling loss with the light emitting / receiving element or the like, so that it is required to finish as smooth as possible. This smooth finish processing of the end face is generally called “termination”.
[0003]
Examples of the termination method include a polishing method, a free cut method, and a hot plate method. Among these methods, the polishing method polishes the end surface, and a highly accurate smooth surface can be obtained, but the processing takes time. The free cut method cuts the end face smoothly and can be processed in a short time, but high smoothness is difficult to obtain.
The hot plate method is a termination method that takes advantage of the characteristics of a plastic optical fiber, and is a method in which an end face is pressed against a smooth hot plate to be softened or melted and flattened. This hot plate method has an advantage that a smooth end face with higher accuracy than the free cut method can be obtained in a shorter time than the polishing method.
[0004]
A specific example of the hot plate termination method will be described with reference to the drawings.
As shown schematically in FIG. 4, first, the tip of the optical fiber 1 cut by a cutter is inserted into an insertion hole 4a formed in a ferrule 4 of a connector plug (not shown), and the end face 2 of the optical fiber 1 is inserted into the end face 2 of the optical fiber 1 as described above. For example, the ferrule 4 protrudes from the tip surface by about 0.3 mm. A tapered hole 4b whose diameter increases outward from the insertion hole 4a is formed at the tip of the ferrule 4, and in the state where the optical fiber 1 is inserted, the volume of the gap space 7 formed by the tapered hole 4b is as follows. The volume of the protruding portion of the optical fiber 1 is substantially equal.
[0005]
Next, the end face 2 of the optical fiber 1 supported by the ferrule 4 is pressed against the hot plate 101 heated to about 160 ° C. of the hot plate heater 100, for example, for 5 seconds to 10 seconds. During this time, the protruding portion of the optical fiber 1 is thermally softened or melted, and the softened and melted portion fills the gap space 7 of the ferrule. Finally, as shown in FIG. Come into contact.
In this state, the end face 2 of the optical fiber is brought into close contact with the smooth hot plate 101 and formed flat. When the temperature of the hot plate 101 is lowered while maintaining this pressed state, the end face 2 of the optical fiber is cooled and solidified while maintaining smoothness, and the termination process is completed.
[0006]
An example of a conventional hot plate heater used in the hot plate termination method is shown in FIG. In the hot plate heater 100, the hot plate 101 is mounted on the top surface of the casing, and the power cord 102 is drawn out from the side of the casing, and a knob 103 for controlling the temperature of the hot plate 101. Etc. are installed.
[0007]
The heat plate 101 is heated to about 160 ° C. as described above, and then the heat cycle of cooling to the temperature equal to or lower than the thermal softening temperature of the optical fiber 1 is repeated. Rapid cooling heat cycle is required. Therefore, the heating plate 101 is not directly heated by an electric heating means, but a heating block incorporating an electric heating body is always heated to a predetermined temperature inside the casing of the heating plate heater 100 to heat the heating plate 101. When the knob 103 is pushed by hand, the heating block is raised by the interlocking mechanism and brought into close contact with the back surface of the hot plate 101, the hot plate 101 is heated by heat transfer, and the hot plate 101 is cooled. A mechanism is employed in which the pressing of the knob 103 is released, the heating block is lowered by an interlocking mechanism and separated from the hot plate 101, and the hot plate 101 is cooled by natural cooling or ventilation cooling.
[0008]
[Problems to be solved by the invention]
The heating plate 101 is repeatedly heated at a very high frequency during the termination of the optical fiber. During this time, the heating block is continuously heated while repeating the up and down movement. In this state, the electric heating body incorporated in the heating block is easily deteriorated or disconnected. However, in the conventional heating block, since the electric heating element is incorporated and fixed in the heating block, the user cannot easily replace only the electric heating element. They had to be repaired by bringing them to the heater manufacturer. In each case, much time and cost were required, and the production efficiency was significantly reduced.
The present invention has been made to solve the above-mentioned problems, and therefore the object thereof is to provide a light that allows the user to easily replace only the heating element, thereby saving time and cost. It is to provide a hot plate heater for fiber termination.
[0009]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides a heating plate having a flat surface that terminates by pressing an end face of an optical fiber, and a heating surface having a heat transfer surface that is in close contact with the back surface of the heating plate. An optical fiber termination hot plate heater (hereinafter simply referred to as “hot plate heating”) including a block and an electric heating element that is freely inserted into and removed from an insertion hole formed in the heating block and is freely connected to and detached from the power supply unit. A container).
[0010]
Since this heating plate has a heat transfer surface that the heating block adheres freely to the back surface of the heating plate, if the heating block is heated to a predetermined temperature by an electric heater, the heating block The heat plate can be rapidly heated to a predetermined temperature by closely contacting the heat plate, and the heat plate can be rapidly cooled below the softening point temperature of the optical fiber by separating the heating block from the heat plate. .
In addition, since the electric heating element can be freely inserted into and removed from the heating block and can be freely attached to and detached from the power supply unit, the heating plate heater can be used when the electric heating element deteriorates or breaks during operation. By simply pulling out the heating block and disconnecting it from the power source, the termination worker can replace the electric heating element in the field very easily and in a short time. At the time of replacement, it is only necessary to prepare a heating element with a connector to be connected to the power source as a spare, so that the time and cost for maintenance can be significantly reduced.
[0011]
The heating block is preferably provided with a locking member that prevents the electric heating element from falling off.
During the termination process, the heating block is repeatedly detached and attached to heat and cool the hot plate, and the electric body may fall out of the insertion hole due to vibrations accompanying the attachment and detachment movement. If the locking member is attached to the heating block, this drop-out can be prevented.
[0012]
In particular, the electric heating body has an extension portion extending outward from the heating block in a state of being inserted into the insertion hole, and the locking member has an opening through which the extension portion of the electric heating body is inserted. The opening is urged so as to always incline from a plane perpendicular to the axis of the electric heating body, and when the inclination is made, the edge of the opening contacts the extension portion of the electric heating body to prevent falling off, against the urging It is preferable that the heating element can be freely inserted and removed when the opening is perpendicular to the axis of the heating element.
[0013]
The locking member is urged so that the opening is always inclined, and the edge of the opening is in contact with the extension of the electric heating element, so that the heating block repeats the attaching / detaching motion to the hot plate during the termination operation. However, the electric heater does not fall out of the insertion hole due to the movement. When the electric heating element is replaced, the electric heating element can be freely inserted and removed through this opening by pressing the locking member with a finger so that the opening is orthogonal to the axis.
[0014]
It is preferable that the heat transfer surface of the heating block is formed in a dimension shape that substantially covers the entire back surface of the hot plate. As a result, when the hot plate is heated, heat transfer from the heating block to the hot plate is performed more rapidly and uniformly.
[0015]
It is preferable that a thermistor for temperature measurement is embedded in the heating block. The softening to melting rate of the end face of the optical fiber depends on the surface temperature of the hot plate, but it is difficult to substantially control the temperature even if the surface temperature of the hot plate that repeats a rapid heat cycle is measured. Since the surface temperature of the hot plate can be determined using the temperature of the heat transfer surface of the heating block and the contact time as parameters, measure the temperature of the heat transfer surface of the heating block that is constantly heated with a thermistor so that it becomes a predetermined temperature. By controlling the amount of power supplied to the heating element and setting the contact time with the heat plate to be constant, it is possible to terminate the optical fiber at an appropriate temperature for a specific optical fiber. The pressing time of the hot plate can also be made constant.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
In FIG. 1, this hot plate heater 10 is an instrument that terminates an end surface 2 of an optical fiber 1 inserted through a ferrule 4 by pressing it against a flat hot plate 11. A heating plate 12 having a flat surface for pressing and terminating, a heating block 12 having a heat transfer surface 12a that adheres freely to the back surface of the heating plate 11, and is formed on the heating block 12. The electric heating body 13 has a columnar electric heating element 13 that can be freely inserted into and removed from the insertion hole 12b. A cord 14 is drawn out from one end of the electric heating element 13, and the cord 14 is connected to the connector 15. The connector 15 is detachably connected to the control circuit board 30 serving as a power supply unit.
[0017]
In the hot plate heater 10, the heating block 12 has a heat transfer surface 12 a that is freely attached to and detached from the back surface of the hot plate 11, so that the heating block 12 is always heated to a predetermined temperature by the electric heater 13. If so, the hot plate 11 can be rapidly heated or cooled by detaching the hot plate 11 and the heating block 12, and the optical fiber 1 can be terminated with high production efficiency.
In addition, the heating plate heater 10 has an electric heating element 13 that can be freely inserted into and removed from the heating block 12 and can be freely attached to and detached from the control circuit board 30 that is a power source via the connector 15. When the electric heating element 13 deteriorates or breaks in the inside, the electric heating element is simply pulled out from the heating block 12 and separated from the control circuit board 30 by the connector 15, so that the termination worker can carry out electric heating in the field very easily and in a short time. The body 12 can be exchanged. At the time of replacement, it is only necessary to prepare an electric heating element with a connector as a spare, so that the time and cost for maintenance can be significantly reduced.
[0018]
The electric heating element 13 has an extension 13a extending coaxially outward from the heating block 12 in a state of being inserted into the insertion hole 12b of the heating block, and the extension 13a is shown in FIGS. (A) It is latched by the heating block 12 by the latching member 16 demonstrated in detail by (b).
[0019]
As shown in FIG. 2, the locking member 16 is formed from a leaf spring material, and an opening 16a through which the extension portion 13a of the electric heating body is inserted is formed at the center. One end portion 16b of the member extending in the left-right direction from the opening 16a is fixed to the side surface of the heating block 12, and the other end portion is a free end to form a finger pressing portion 16c. As shown in FIG. 3A, the opening 16 a of the locking member is biased so as to be inclined from a plane Y orthogonal to the axis X of the electric heating body 13. In this inclined state, the outer edge of the opening 16a comes into contact with the side surface of the extension portion 13a, and if the side surface of the extension portion 13a is soft, it is pressed so as to bite into it. It prevents it from falling out. Therefore, even if the heating block 12 repeats the attaching / detaching movement with respect to the hot plate 11 during the termination work or vibrates due to other causes, the electric heating element 13 falls out from the insertion hole 12b of the heating block due to the movement or vibration. There is no.
[0020]
When the electric heating element 13 is replaced, if the finger pressing portion 16c is pushed by hand against the urging so that the opening 16a of the locking member coincides with the surface Y orthogonal to the axis X, the electric heating element 13 is The locking member can be freely inserted and removed through the opening 16a, and the locking member does not hinder the replacement of the electric heating element.
[0021]
As shown in FIG. 1, the heating block 12 is mounted on a lifting mechanism 20 that moves up and down in conjunction with the vertical movement of the manual lever 21. The elevating mechanism 20 is attached to the lower surface of the heating block 12 and is given elasticity in the vertical direction so that the heat transfer surface 12a is in close contact with the back surface of the hot plate 11 when the heating block is raised. A resilient frame 26, a slide frame 22 that supports the resilient frame 26 from below, a support frame 23 that is fixed to the housing and supports the slide frame 22 to freely slide up and down, and heating And a coil spring 24 biased so as to always pull the block 12 downward. A knob 21 a for pushing down with a finger is attached to an end portion of the manual lever 21 that extends outside the casing, and the other end portion 21 b is connected to the bottom of the slide frame body 22. Is supported by a fulcrum member 25 extending from the housing so as to rotate in the vertical direction.
[0022]
A thermistor 31 is built in the heating block 12, and the thermistor 31 is connected to a temperature measuring circuit of the control circuit board 30 through a lead 32. Further, a flashing lamp 33 is mounted on the upper surface of the casing, and is connected to the timer circuit of the control circuit board 30 via the lead 34.
The control circuit board 30 is supplied with electric power from the power cord 35, supplies electric power controlled to the electric heating body 13 so that a predetermined temperature monitored by the thermistor 31 is maintained, and the flashing lamp 33 is supplied with, for example, 1 Flashes every second.
[0023]
The termination operation is started after the heating block 12 is heated to a predetermined temperature of, for example, 160 ° C. by the control circuit board 30 and the blinking lamp 33 is activated. First, when the knob 21 a of the manual lever is pushed down, the manual lever 21 is rotated and the slide frame body 22 is raised, and the heating block 12 mounted on the resilient frame 26 is energized by the coil spring 24. The heat transfer surface 12a rises against the surface and uniformly contacts the back surface of the hot plate 11 to raise the hot plate 11 to a predetermined temperature. When the end face 2 of the optical fiber 1 is pressed against the surface of the hot plate 11 and is released from the knob 21a after a predetermined time counted by the flashing lamp 33 while being pressed, the heating block 12 is moved from the hot plate 11 by the coil spring 24. As a result, the surface temperature of the hot plate 11 rapidly drops below the thermal softening temperature of the optical fiber 1. As a result, the end face 2 of the optical fiber is cooled and solidified while maintaining a smooth state, and one termination process is completed.
[0024]
【The invention's effect】
The hot plate heater for optical fiber termination according to the present invention includes an electric heating element that is freely inserted into and removed from a heating block that is freely attached to and detached from the back surface of the hot plate that terminates the end face of the optical fiber, and is attached to and detached from the power supply unit Because it is connected freely, if the electric heating element deteriorates or breaks during the work, it is very easy and short for termination workers on site to pull out the electric heating element from the heating block and disconnect it from the power source. The electric heating element can be replaced in time.
If the heating block is equipped with a locking member that has an opening that is biased so as to incline from the plane perpendicular to the axis of the electric heating element, the electric heating element can be effectively prevented from falling off with a simple structure. Moreover, the replacement work is not hindered when the electric heating element is replaced.
[Brief description of the drawings]
1 is a cross-sectional view showing an embodiment of the present invention. FIG. 2 is a perspective view showing a locking member in the embodiment. FIGS. 3A and 3B are views of the locking member in the embodiment. FIG. 4 is a cross-sectional view showing a process of a general optical fiber termination operation. FIG. 5 is a cross-sectional view showing another process of the termination operation. FIG. Perspective view showing hot plate heater for termination [Explanation of symbols]
1: optical fiber 2: end face 4: ferrule 10: hot plate heater 11: hot plate 12: heating block 12a; heat transfer surface 12b; insertion hole 13: electric heating element 13a; extension 15: connector 16: locking member 16a Opening 16c; finger pressing part 30: control circuit board

Claims (1)

A hot plate heater that terminates by pressing an end face of a plastic optical fiber against a flat hot plate,
A heating plate having a flat surface that presses and terminates the end face of the optical fiber, a heating block having a heat transfer surface that adheres freely to the back surface of the heating plate, and an insertion formed in the heating block possess a is freely inserted or disconnect the hole electric heater,
The electric heating body has an extension portion extending outward from the heating block in a state of being inserted into the insertion hole, and a cord drawn from one end portion is freely connected to the power supply portion ,
A locking member that prevents the electric heating element from falling off is attached to the heating block,
The locking member has an opening through which the extension portion of the electric heating element is inserted, and this opening is urged so as to always incline from a plane perpendicular to the axis of the electric heating element. An optical fiber characterized in that when the opening is made perpendicular to the axial center of the heating element against the biasing force, the heating element can be freely inserted and removed in contact with the extension portion of the heating element. Termination hot plate heater.

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