JP2009092406A - Case structure of optical fiber gyro - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve an antiradiation property of an optical fiber coil by forming a part of a case from a lead-containing resin. <P>SOLUTION: This case structure of an optical fiber gyro is equipped with: a bobbin body 2 having the optical fiber coil 4; and the first lid body 6, an outer cylindrical body 5, and the second lid body 7 for covering the bobbin body 2 and the optical fiber coil 4. At least the first lid body 6 is formed from the lead-containing resin. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a case structure of an optical fiber gyro, and in particular, by using a lead-containing resin as a material of the first lid on at least the front side of the case, the radiation resistance of the optical fiber coil due to external radiation is improved, The present invention relates to a novel improvement for improving the lifetime of an optical fiber gyro.

Conventionally, as this type of optical fiber gyro that has been used, for example, the configuration disclosed in Patent Document 1 can be cited. As described above, the case structure of the optical fiber gyro disclosed in Patent Document 1 can be exemplified. For example, the configuration shown in FIG. 2 was adopted.
That is, what is indicated by reference numeral 1 in FIG. 2 is a case in which the overall shape is a box shape, and inside this case 1 is a bobbin body 2 in which the overall shape is a cylindrical shape and is substantially H-shaped in the longitudinal sectional shape. Is provided.

  An optical fiber coil 4 as a sensing coil is wound around the outer periphery of the cylindrical portion 3 formed on the outer edge of the bobbin body 2, and is provided on the outer periphery of the optical fiber coil 4 of the bobbin body 2. A cylindrical outer cylinder 5 is disposed, and this outer cylinder 5 is connected to a first lid 6 provided on the front side of the bobbin body 2.

A second lid body 7 provided on the back side of the bobbin body 2 is connected to the outer cylinder body 5, and the first lid body 6, the outer cylinder body 5 and the second lid body 7 are configured as separate bodies. Yes.
A screw hole 8 is formed at a central position of the bobbin body 2, and a screw 9 provided in the second lid body 7 protrudes upward through the screw hole 8. The bobbin body 2 is fixed.

A screw hole 9 a is formed at the tip of the screw 9, and a circuit board 12 is fixed to the screw hole 9 a via a collar 10 and a mounting screw 11.
Further, first and second couplers 13 and 24 and a polarizer 23 are provided on the back surface of the bobbin body 2, and the case 1 is formed by the first lid body 6, the outer cylinder body 5 and the second lid body 7. It is configured.
Further, the inside of the case 1 is constituted by the bobbin body 2 so that the front side is an electric first chamber 1A and the back side is a mechanical second chamber 1B.

The optical fiber gyro 20 having the configuration shown in FIG. 2 includes, as an example, a phase modulation type optical system 21 and a signal processing circuit 36 using the well-known optical Sagnac effect (disclosed in Patent Document 1) shown in FIG. It is constituted by.
That is, what is denoted by reference numeral 21 in FIG. 3 is an optical system having a sensing coil 4 formed of an optical fiber, and this sensing coil 4 is a light source via a first coupler 13, a polarizer 23, and a second coupler 24. The module 25 and the detector 26 are connected by an optical fiber 27.

Between the sensing coil 4 and the first coupler 13, a phase modulator 28 made of a known piezo element (PZT) is provided in contact with the optical fiber 27 and located in the vicinity of the sensing coil 2. .
By driving the phase modulator 28 with an alternating current signal having a predetermined frequency, the phase difference of the light generated by the angular velocity is caused to interfere, and the gyro output 36a is obtained through the signal processing circuit 36 by a known optical Sagnac effect.

JP 2004-191239 A

Since the conventional optical fiber gyro case structure is configured as described above, the following problems exist.
That is, since the first lid, the outer cylinder, the second lid, etc. constituting the case are all made of only an aluminum alloy or a resin, the optical fiber gyroscope is used in a radiation environment such as outer space and radiation management area. When used underneath, the radiation 30a enters the optical fiber coil through the case from the external radiation source 30 and shortens the life of the optical fiber coil.

Moreover, as a means for protecting the optical fiber coil as described above from the radiation from the outside, for example, a method of shielding radiation by providing a lead plate inside the case, or in the glass of the optical fiber coil There is a method to remove phosphorus (P) in advance and improve the radiation resistance of the optical fiber coil itself, but in the former case, the mass of the optical fiber gyroscope is greatly increased due to the large specific gravity of lead when shielding with a lead plate Was supposed to increase.
In the latter case, the cost of the optical fiber coil itself has been significantly increased, making it difficult to meet the need for lower prices.

  An optical fiber gyro case structure according to the present invention includes a bobbin body having an optical fiber coil wound around a periphery, and a first lid body and an outer cylinder body for covering the bobbin body and the optical fiber coil. Provided, at least the first lid body is formed of a lead-containing resin, and the bobbin body, the first lid body, and the outer cylinder body are configured separately from each other, and The first lid body and the outer cylinder body are integrally formed with each other, and the optical fiber coil is insert-molded in the bobbin body, and on the opposite side of the bobbin body to the first lid body. Is a configuration in which a second lid is provided, and the second lid is fixed to the bobbin body by a screw penetrating the bobbin body.

Since the case structure of the optical fiber gyro according to the present invention is configured as described above, the following effects can be obtained.
That is, since at least the first lid of the case is formed of lead-containing resin, radiation from the outside is shielded on the outside of the case, and radiation can be prevented from entering the optical fiber coil. In addition, the radiation resistance of the optical fiber gyro can be improved at low cost.
In addition, since the case resin is formed from lead-containing lead-containing acrylic resin, lead-containing methacrylic resin, or the like, the case manufacturing method is the same as that of the conventional method, and an increase in cost can be avoided.

  In the present invention, the material of the first lid on at least the front side of the case is made of lead-containing resin, so that the radiation resistance of the optical fiber coil due to external radiation is improved and the life of the optical fiber gyro is improved. An object of the present invention is to provide a case structure for an optical fiber gyroscope.

A preferred embodiment of the case structure of an optical fiber gyro according to the present invention will be described below with reference to the drawings.
In addition, the same code | symbol is demonstrated to the part which is the same as that of a prior art example, or an equivalent part.
In FIG. 1, reference numeral 1 denotes a case in which the overall shape is a box shape, and a bobbin body 2 having an overall shape of a cylindrical shape and a substantially H-shaped longitudinal section is provided inside the case 1. It has been.

  An optical fiber coil 4 as a sensing coil is wound around the outer periphery of the cylindrical portion 3 formed on the outer edge of the bobbin body 2, and is provided on the outer periphery of the optical fiber coil 4 of the bobbin body 2. A cylindrical outer cylinder 5 is disposed, and this outer cylinder 5 is connected to a first lid 6 provided on the front side of the bobbin body 2. The first and second couplers 13 and 24 and the polarizer 23 are provided on the back surface of the bobbin body 2.

A second lid body 7 provided on the back side of the bobbin body 2 is connected to the outer cylinder body 5, and the first lid body 6, the outer cylinder body 5 and the second lid body 7 are configured as separate bodies. And the case 1 is formed.
The first lid body 6, the outer cylinder body 5, and the second lid body 7 are not limited to being formed separately as described above, but the first lid body 6, the outer cylinder body 5, The optical fiber coil 4 can be insert-molded in the bobbin body 2.

  Of the case 1 formed by the first lid body 6, the outer cylinder body 5, and the second lid body 7, at least the first lid body 6 or the first lid body 6 and the outer cylinder body 5 Unlike the conventional material, the second lid body 7 is formed by resin molding using a lead-containing resin made of a lead-containing acrylic resin or a lead-containing methacrylic resin. Further, when the bobbin body 2 is also formed of a lead-containing resin, the radiation resistance is further improved.

Therefore, when the optical fiber gyroscope 20 having the above-described configuration is used, when the second lid body 7 is attached to a device (not shown) with the second lid body 7 on the lower side, at least only the first lid body 6 or the first lid body 6 and the outside. Since the cylindrical body 5 is formed of lead-containing resin, for example, the radiation 30a emitted from the radiation source 30 is shielded by the first lid 6 and is not incident on the optical fiber coil 4 and the electronic component. The radiation resistance of the fiber gyro coil 4 can be improved as compared with the conventional case.
Since the optical system 21 and the signal processing circuit 36 of each chamber 1A, 1B of the optical fiber gyro 20 are the same as those in FIG. 3, the description thereof is omitted here.

It is sectional drawing which shows the case structure of the optical fiber gyroscope by this invention. It is sectional drawing which shows the case structure of the conventional optical fiber gyro. It is a block diagram which shows the optical system and electrical system of the conventional optical fiber gyro.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Case 1A 1st chamber 1B 2nd chamber 2 Bobbin body 3 Cylinder part 4 Optical fiber coil 5 Outer cylinder body 6 1st lid body 7 2nd lid body 8 Screw hole 9 Screw 9a Screw hole 10 Collar 11 Mounting screw 12 Circuit board 23 Polarizer 13 First coupler 14 Second coupler 20 Optical fiber gyro 30 Radiation source 30a Radiation

Claims (5)

A bobbin body (2) having an optical fiber coil (4) wound around the periphery, a first lid (6) and an outer cylinder for covering the bobbin body (2) and the optical fiber coil (4) A body (5), and
An optical fiber gyro case structure, wherein at least the first lid (6) is made of a lead-containing resin.   The case structure of an optical fiber gyro according to claim 1, wherein the bobbin body (2), the first lid body (6), and the outer cylinder body (5) are formed as separate bodies.   The first lid (6) and the outer cylinder (5) are integrally formed with each other, and the optical fiber coil (4) is insert-molded with the bobbin body (2). The optical fiber gyro case structure described.   The optical fiber according to any one of claims 1 to 3, wherein a second lid (7) is provided on a side of the bobbin body (2) facing the first lid (6). Gyro case structure.   The case structure of an optical fiber gyro according to claim 4, wherein the second lid (7) is fixed to the bobbin body (2) by a screw (9) passing through the bobbin body (2). .

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