JP2002277371A - Device and method for inspecting hole of ferrule - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify constitution to reduce a cost, make a ferrule easily set without any obstacle, and efficiently inspect holes of the plural ferrules at the same time. SOLUTION: This hole inspection device for inspecting clogging of the through hole 5 of the injection-molded ferrule 2 is provided with a receiving member 14 provided with an intake hole communicated with the through hole 5, and for receiving a lower end part of the ferrule 2 substantially air-tightly, a cylinder chamber 20 communicated to the intake hole, a piston 21 or the like for pressure-reducing air pressure in the cylinder chamber 20, and an air- pressure sensor 26 for detecting an air-pressure change after the pressure reduction of the cylinder chamber 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ferrule which is a member for holding an optical fiber in an optical connector, and more particularly to a hole inspection apparatus and a hole inspection method for inspecting a clogged through hole of a ferrule after injection molding. Things.

[0002]

2. Description of the Related Art FIG. 5 shows a ferrule molded product 51 which is injection-molded. The ferrule molded product 51 is formed by kneading ceramic powder such as zirconia or plastic such as epoxy resin into a mold by an injection molding machine. Things. The ferrule 52 to be a product is formed, for example, by integrally forming a shaft portion 53 and a flange portion 54 protruding in a radial direction from one end portion or an intermediate portion thereof. I have. Usually, the ferrule molded product 51 is a ferrule 52
, That is, a plurality of (four in the illustrated example) ferrules 52 are connected by a sprue 56, a runner 57 and the like.

[0003] The through hole 55 is for passing an optical fiber and has a fine inner diameter of 100 to 200 µm and is formed with high precision. However, the core pin for forming the through-hole 55 may be broken at the time of injection molding, or a molding failure may occur, and the through-hole 55 may be clogged. Thus, the ferrule molded product 51 after the injection molding is taken out of the injection mold by the take-out machine, and is subjected to a hole inspection device to inspect the through-hole 55 for clogging.

[0004] As shown in FIG.
A transparent table 61 on which the ferrule molded product 51 taken out of the injection mold is placed in a posture in which the ferrule 52 stands,
A light source 62 for illuminating light from below to above the table 61;
An image pickup device 6 such as a CCD camera that captures light passing through the through hole 55 through the table 61 from directly above the ferrule 52.
3, an image processing device 64 that performs image processing on the light captured by the image pickup device 63, and a display device 65 such as a display that displays the processed image. Based on the image thus obtained, for example, if a light spot is recognized in the image, the through hole 55 is not clogged.
5 was determined to be clogged.

[0005]

However, the conventional hole inspection apparatus and the conventional hole inspection method have the following problems. The hole inspection device that requires the light source 62, the image pickup device 63, the image processing device 64, and the display device 65 has a complicated configuration and is expensive. Since it is difficult to provide many expensive hole inspection devices, usually only one is provided and a plurality of ferrules 5 are taken.
The holes 2 were inspected one by one by rotating the table 61 intermittently corresponding to the hole inspection device. Therefore, the inspection efficiency was poor. If the image pickup device 63 is located above the table 61, the image pickup device 63 becomes an obstacle when the ferrule molded product 51 is set on the table 61 by the unloader. For this reason,
It is necessary to move the table 61 to a place where the image pickup device 63 is not located above, place the ferrule molded product 51 on the table 61 and set it, and then move the table 61 to a position below the image pickup device 63 again.

An object of the present invention is to provide a hole inspection apparatus which solves the above-mentioned problems, simplifies the configuration, can be inexpensive, and can easily set a ferrule without any obstacle. Because of the low cost, a plurality of main parts can be provided, and hole inspection of a plurality of ferrules can be performed efficiently simultaneously. Another object of the present invention is to provide a hole inspection method capable of easily performing a hole inspection with such a simple and inexpensive apparatus.

[0007]

In order to solve the above problems, the following means (1) and (2) of a hole inspection apparatus and means (3) of a hole inspection method are employed.

(1) In a hole inspection device for inspecting clogging of a through hole of an injection molded ferrule, a receiving member having an intake hole communicating with the through hole and receiving one end of the ferrule in a substantially airtight manner, and an intake hole A measurement chamber communicating with the
A hole inspection device for a ferrule, comprising: a transformer for reducing or increasing the pressure in a measurement chamber; and a pressure sensor for detecting a pressure change after the pressure reduction or pressure increase in the measurement chamber.

Here, the direction of the receiving member and the supply direction of the ferrule are not particularly limited, but it is preferable that the receiving member is provided upward and the ferrule is supplied to the receiving member from above.

It is preferable that the receiving member is replaceably provided with a receiving member having a shape and a size matching the shape and the size of the ferrule.

Further, the measuring chamber and the pressure reducing device are not limited to a specific structure. However, it is possible to exemplify an embodiment in which the measuring chamber is a cylinder chamber, and the transformer is a piston inserted into the cylinder chamber and a driving device thereof.

When inspecting a plurality of ferrules connected by a runner or the like, it is preferable that a plurality of sets of receiving members, measuring chambers, transformers, and pressure sensors are provided so as to match the number and positions of the ferrules.

(2) In a hole inspection method for inspecting clogging of a through-hole of an injection-molded ferrule, one end of the through-hole is decompressed or increased in pressure, and the pressure is changed based on a change in air pressure after decompression or increase in pressure of the one end. A method for inspecting a hole in a ferrule, comprising determining whether a through hole is clogged.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
This will be described with reference to FIG. The upper part of FIG. 2 shows an injection-molded ferrule molded product 1, which is formed by kneading ceramic powder such as zirconia or injecting plastic such as epoxy resin into a mold by an injection molding machine. . The ferrule 2 to be a product has, for example, a shaft portion 3 and a circular flange portion 4 protruding in a radial direction from one end portion or an intermediate portion thereof, and is formed integrally with the shaft portion 3.
Fine through-holes 5 of 00 to 200 μm are formed.
Usually, the ferrule molded product 1 takes a plurality of ferrules 2,
That is, a plurality of (four in the illustrated example) ferrules 2 are formed in a state of being connected by a runner or the like. As a result, the center sprue 6 and the branch 7 radially extending from the sprue 6
The ferrule 2 has an unnecessary portion including a plurality of runners 7 including a and a peripheral ring 7 b at the tip thereof and a gate 8 at a boundary between an inner peripheral edge of the peripheral ring 7 b and an outer peripheral edge of the flange portion 4.

FIGS. 1 and 2 show a hole inspection apparatus for inspecting a clogged through hole 5 of an injection molded ferrule 2. FIG. The hole inspecting device is mainly composed of a main body block 11, and a positioning member having a fitting groove 13 in the center of the upper surface of the main body block 11 for positioning the ferrule molded product 1 by fitting a branch 7 a of a runner 7. 12 are attached. The main body block 11 includes a receiving member 14, a cylinder chamber 20 as a measurement chamber, and a piston 21 as a transformer for reducing the air pressure in the cylinder chamber 20.
And a driving device 23 thereof and a pressure sensor 26 for detecting a pressure change after the pressure in the cylinder chamber 20 is reduced.
A plurality of sets are provided to match the number and position of the ferrules 2.

The receiving member 14 is formed of an elastic material such as rubber, soft resin, soft elastomer, or the like, and a suction cup portion 15 is formed on an upper portion for receiving the lower end portion (the peripheral ring 7b in this example) of the ferrule 2 in a substantially airtight manner. I have. An intake hole 16 communicating with the through hole 5 is formed at the center of the receiving member 14. The receiving members 14 are attached to four portions of the main body block 11 by detachably engaging with mounting members 17 formed of metal, hard resin, or the like and screwed to the main body block 11. Since the receiving member 14 is detachable in this manner, it is possible to easily cope with ferrules 2 having different dimensions and shapes by replacing the receiving member. The attachment member 17 also has a communication hole 18 that communicates with the intake hole 16.

The cylinder chamber 20 as a measuring chamber is connected to the main body block 1 so as to communicate with the intake hole 16 and the communication hole 18.
1 are formed at four places. A piston 21 as a transformer is inserted into the cylinder chamber 20, and a seal ring 22 is provided on the outer periphery near the tip of the piston. The driving device 23 for the piston 21 includes a connecting plate 24 for connecting the four pistons 21 and an air cylinder 25 for moving the connecting plate 24 up and down. The barometric pressure sensors 26 are attached to four positions of the main body block 11 so as to communicate with the upper end of the side wall of the cylinder chamber 20. Each barometric pressure sensor 26
Is connected to a judging device 27 using a microcomputer, and the judging device 27 is configured to judge whether or not the through hole 5 is clogged based on a change in the pressure of the cylinder chamber 20 detected by the pressure sensor 26.

A hole inspection method for inspecting the clogging of the through-hole 5 of the ferrule 2 using the hole inspection apparatus configured as described above will be described in the order of steps.

(1) As shown in FIG. 1, FIG. 2 and FIG. 3 (a), an injection-molded ferrule molded product 1 is gripped by a take-out machine (not shown) and taken out of an injection mold.
It is set on the hole inspection device from above. That is, the branch 7 a of the runner 7 is fitted and positioned in the fitting groove 13, and the peripheral rings 7 b at the lower ends of the four ferrules 2 are placed on the suction cups 15 of each receiving member 14.

(2) Next, as shown in FIG. 3 (b), the four pistons 21 are instantaneously lowered and the cylinder chamber 20 is expanded to instantaneously reduce the air pressure. At this time,
The peripheral ring 7b is substantially airtightly adsorbed to the suction cup portion 15 of the receiving member 14, and since the through-hole 5 is minute, the flow resistance is high and the air does not pass through instantaneously. Negative pressure as shown in the steeply falling part of the solid line graph.

(3) A change in air pressure of each cylinder chamber 20 after decompression is detected by the four air pressure sensors 26. a: If there is no clogging in the through-hole 5, external air is gradually sucked from the through-hole 5 and flows into the cylinder chamber 20 through the intake hole 16 and the communication hole 18, so that the negative pressure in the cylinder chamber 20 is reduced as shown in FIG. , Gradually approaches the atmospheric pressure as shown by the solid line graph a. b: If there is a blockage in the through-hole 5, no or almost no external air is sucked from the through-hole 5, so that the negative pressure in the cylinder chamber 20 is maintained as shown by a one-dot chain line graph b in FIG. Very slowly approaching atmospheric pressure. c: When the ferrule 2 is not placed on the receiving member 14, when the piston 21 descends, external air flows from the intake hole 16 and the communication hole 18 with almost no resistance.
Flows into zero. For this reason, as shown in the two-dot chain line graph c in FIG.

(4) The judging device 27 judges which of the above three patterns a, b, and c the pressure change of the four cylinder chambers 20 detected by the pressure sensor 26 determines.
The presence or absence of the clogging of the through hole 5 or the presence or absence of the ferrule 2 as a sample is determined, and the determination result is notified by, for example, light emission of a lamp or sounding of a buzzer sound or the like. Note that the determination result may be displayed on a display device such as a separately provided display.

The hole inspection apparatus and the hole inspection method according to the present embodiment have the following advantages. The configuration of the hole inspection device can be simplified and inexpensive. Because of the low cost, a plurality of sets of the receiving member 14, the cylinder chamber 20, the transformers (21, 23) and the pressure sensor 26 can be provided so as to match the number and the position of the ferrules 2, and the hole inspection of the plurality of ferrules 2 can be performed efficiently at the same time. Can be done. Therefore, the inspection speed is increased. The hole inspection device can be assembled only at one end (the lower end in this example) of the ferrule 2 and the hole inspection can be performed only from the one end side. It is not necessary to provide an obstacle such as the imager 63. For this reason, the layout is easy, and the receiving member 14
Can be easily mounted and set without any obstacles.

It should be noted that the present invention is not limited to the above-described embodiment, and can be embodied by appropriately changing the scope of the invention as follows, for example, as follows. (1) In the embodiment, the cylinder chamber 20 is depressurized and the subsequent atmospheric pressure change is measured. However, the cylinder chamber 20 may be increased in pressure and the subsequent atmospheric pressure change may be measured. In that case,
The receiving member 14 is provided with a chuck or the like for holding the ferrule 2 so as not to be separated when the pressure is increased. To increase the pressure, the piston 21 may be raised instantaneously. (2) The transformer is not limited to the cylinder / piston mechanism, and may be, for example, a compressor.

[0025]

As described above in detail, according to the ferrule hole inspection apparatus of the present invention, the structure can be simplified and the cost can be reduced, and the ferrule can be easily set without any obstacle. Also, because of the low cost, a plurality of sets of main parts can be provided, and hole inspection of a plurality of ferrules can be performed efficiently simultaneously. Further, according to the ferrule hole inspection method according to the present invention, hole inspection can be easily performed by such a simple and inexpensive apparatus.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing the entire hole inspection apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view when a ferrule is set on a receiving member of the hole inspection apparatus.

FIG. 3 shows a hole inspection method by the hole inspection apparatus, and (a)
3 is a cross-sectional view before depressurizing the cylinder chamber, and FIG. 3B is a cross-sectional view after depressurizing the cylinder chamber.

FIG. 4 is a graph showing a change in air pressure in a cylinder chamber in the hole inspection method.

FIG. 5 is a perspective view showing a conventional hole inspection apparatus and hole inspection method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ferrule molded product 2 Ferrule 3 Shaft part 4 Flange part 5 Through hole 7 Runner 11 Body block 12 Positioning member 13 Fitting groove 14 Receiving member 15 Suction part 16 Intake hole 17 Mounting member 18 Communication hole 20 Cylinder chamber 21 Piston 22 Seal ring 23 Drive 24 Connecting Plate 25 Air Cylinder 26 Barometric Pressure Sensor 27 Judgment Device

Claims (6)

[Claims] 1. A hole inspection device for inspecting clogging of a through hole of an injection-molded ferrule, wherein the receiving member includes an intake hole communicating with the through hole and receives one end of the ferrule in a substantially airtight manner. A measurement chamber communicating with the intake port, a transformer for reducing or increasing the pressure of the measurement chamber, and a pressure sensor for detecting a pressure change after the measurement chamber is depressurized or increased. Ferrule hole inspection device. 2. The ferrule hole inspection device according to claim 1, wherein the receiving member is provided upward, and the ferrule is supplied to the receiving member from above. 3. The ferrule hole inspection apparatus according to claim 1, wherein the receiving member has a replaceable receiving member having a shape and a size matching the shape and the size of the ferrule. 4. The ferrule hole inspection apparatus according to claim 1, wherein the measurement chamber is a cylinder chamber, and the transformer is a piston inserted into the cylinder chamber and a driving device therefor. 5. When inspecting a plurality of ferrules connected by a runner or the like, a plurality of sets of the receiving member, the measuring chamber, the transformer and the pressure sensor are provided so as to match the number and position of the ferrules. The ferrule hole inspection device according to any one of the above. 6. A hole inspection method for inspecting clogging of a through-hole of an injection-molded ferrule, wherein one end of the through-hole is depressurized or increased, and a pressure change at the one end is reduced or increased. A method for inspecting a hole in a ferrule, comprising determining whether a through hole is clogged.