JPH1073669A - Seismometer inclination correcting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To conduct correction of inclination of seismic sensor ginbal-supported in a pressure vessel remotely, simply, in a short time and accurately for wider angle range than previous angle range. SOLUTION: In a seismometer inclination correcting device, a ginbal case 6 is supported with a pressure vessel 1 via rollers 4a, 4b, 4c and 4d touching arc outer surfaces 6a and 6b having a center line of ginbal swinging axis of the ginbal case 6, an operating iron core 12 operated by receiving magnetic force of a permanent magnet 11 constituting the fixing device of the ginbal case 6 stops the ginbal case 6 by magnetic force sticking to the arc outer surface 6b of the ginbal case 6 when stopping and is supported movably to isolate from the arc outer surface 6b of the ginbal case 6 at non-stopping time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismometer inclination correcting device for correcting an inclination of an earthquake sensor supported via a gimbal case in a pressure vessel installed underground.

[0002]

2. Description of the Related Art Conventionally, when a seismic sensor is installed in the ground, the seismic sensor is supported via a gimbal case in a pressure-resistant container, and the pressure-resistant container supporting the earthquake sensor is lowered into the ground. Was to be installed. The underground depth at that time may reach, for example, several thousand meters, and when installing the pressure-resistant container at the installation position, precise work is required to position the reference line of the earthquake sensor in a predetermined direction. . In addition, after a large earthquake or when the seismometer is used for a long period of time, the direction of the base line of the underground seismic sensor must be checked, and the inclination of the seismic sensor must be corrected if necessary. No.

[0003]

However, if the direction of the reference line of the seismic sensor does not coincide with the desired direction, the maximum sensitivity direction of the seismic sensor cannot be directed to the desired direction. In general, it is very difficult to match the direction of the reference line of an earthquake sensor in a pressure vessel installed underground with a desired direction. Since there was no appropriate means that could easily correct the direction of the seismic sensor, it took a lot of time and effort to correct the direction of the reference line of the seismic sensor to the desired direction, and it was necessary to make the correction. The range of angles that can be controlled was limited.

Accordingly, the present invention provides a method for correcting a tilt of a seismic sensor when a pressure-resistant container having a seismic sensor supported inside is installed in the ground, or a tilt accompanying inspection of a seismic sensor installed in the ground. It is an object of the present invention to provide a seismometer tilt correction device capable of performing remote correction simply and easily in a short time and over a wider angle range than the conventional correctable angle range.

[0005]

In order to achieve the above-mentioned object, a seismometer inclination correcting device according to the present invention comprises a gimbal case for supporting an inclination of an earthquake sensor supported through a gimbal case in a pressure vessel installed underground. In a seismometer tilt correction device for correcting, a weight that automatically corrects the tilt of the gimbal case by gravity so that the direction of the reference line of the seismic sensor forms a predetermined angle with respect to the vertical direction, Applies a braking force to the gimbal case and fixes the gimbal case to the pressure-resistant container. However, when the braking force is remotely released, the inclination of the gimbal case causes the action of the weight. And a gimbal case fixing device that allows a free tilt correction movement of the gimbal case so that the gimbal case is automatically corrected by the gimbal case. Further, in the seismometer tilt correction device of the present invention, the gimbal case fixing device,
A permanent magnet supported by the pressure-resistant container, and at least a magnetic flux canceling coil that generates a magnetic flux in a direction to cancel the magnetic flux of the permanent magnet when energized, and when the magnetic flux canceling coil is not energized, By applying a braking force to the gimbal case by the magnetic force of the permanent magnet, the gimbal case is fixed to the pressure-resistant container, and when the magnetic flux canceling coil is energized, the magnetic flux canceling coil is generated. By canceling at least a part of the magnetic flux of the permanent magnet by the generated magnetic flux, the braking force on the gimbal case is released, and a free tilt correction movement of the gimbal case is allowed. Further, in the seismometer tilt correction device of the present invention, the gimbal case is supported by the pressure-resistant container via a roller circumscribing an arc-shaped outer peripheral surface having a center line about a gimbal swing axis of the gimbal case, The operating iron core that operates by receiving the magnetic force of the permanent magnet that constitutes the gimbal case fixing device brakes the gimbal case by applying magnetic force to the arc-shaped outer peripheral surface of the gimbal case during braking, and the gimbal when not braking. The case is movably supported so as to be separated from the arc-shaped outer peripheral surface of the case. In the seismometer inclination correction device of the present invention,
The upper end surface of the operating core is opposed to the lowermost end of the downward arcuate outer peripheral surface of the gimbal case, and the magnetic fluid filled in the magnetic fluid reservoir formed on the upper end surface portion of the operating core is always filled with the magnetic fluid. It is in contact with the arc-shaped outer peripheral surface.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 and 3, partitions 2 and 3 are formed in a cylindrical pressure vessel 1 installed in the ground to partition the interior of the pressure vessel in an axial direction. Reinforcing rods 9a, 9b disposed between each other,
The partition walls 2, 3 reinforced by 9c and 9d rotatably support the rollers 4a, 4b, 4c, and 4d via brackets on surfaces facing each other, respectively. Between 4d, a gimbal case 6 supporting the earthquake sensor 8 is swingably supported around the swing axis of the gimbal case 6.

An arc-shaped outer peripheral surface 6a is formed on an upper outer peripheral portion of the gimbal case 6, and an arc-shaped outer peripheral surface 6b is formed on a lower outer peripheral portion of the gimbal case 6.
An arc-shaped guide ridge is formed on each of the arc-shaped outer peripheral surfaces 6a and 6b along the center line. On the other hand, each roller 4a,
4b, 4c, and 4d each have a pair of left and right roller portions and a roller shaft portion that interconnects the pair of right and left roller portions, and the left and right end portions of the roller shafts of the upper rollers 4a, 4b are Each is supported by a pair of left and right brackets projecting from the partition wall 2 and has a lower roller 4c,
The left and right ends of the 4d roller shaft are supported by a pair of left and right brackets projecting from the partition wall 3, respectively. Therefore, the arc-shaped guide ridge formed on the upper arcuate surface 6a restricts the movement of each roller 4a, 4b in the roller axis direction between the pair of left and right roller portions of each upper roller 4a, 4b. An arcuate guide ridge formed on the lower arcuate surface 6b regulates the movement of each roller 4c, 4d in the roller axial direction between a pair of left and right roller portions of each lower roller 4c, 4d. As a result, the movement of the gimbal case 6 in the swing axis direction of the gimbal case 6 is restricted, and the swing axis of the gimbal case 6 is always in a fixed direction with respect to the pressure-resistant container 1. Will be maintained.

A weight 6c is provided at the lowermost end of the gimbal case 6.
Is attached. This weight 6c is used as the gimbal case 6.
The weight 6c is always attached to the lowermost end of the gimbal case 6 even if the gimbal case 6 is tilted around the pivot axis, unless a special braking force is applied to the gimbal case 6. The restoring moment due to gravity is applied to the gimbal case 6 so as to return to the position. As a result, the weight 6c moves the gimbal case so that the direction of the reference line of the earthquake sensor 8 forms a predetermined angle with respect to the vertical direction. 6
Automatically corrects the tilt around the swing axis.

Inside the pressure vessel 1, a magnet support plate 10 that is elastically deformable in the axial direction of the pressure vessel 1 is provided at a position separated from the partition 3 on the side opposite to the partition 2. A permanent magnet 11 is mounted on the upper surface side of the magnet support plate 10, that is, on the partition wall 3 side. The operating iron core 12 constituting the magnetic pole of the permanent magnet 11 passes through a through hole 13 formed at the center of the partition wall 3 so as to be vertically movable in the axial direction of the pressure-resistant container 1. Is formed in a concave shape having the same curvature as the arc-shaped outer peripheral surface 6b, and faces the arc-shaped outer peripheral surface 6b. A magnetic flux canceling coil 14 that generates a magnetic flux in a direction to cancel the magnetic flux of the permanent magnet 11 when energized is disposed on a side peripheral portion of the working iron core 12. The energization of the magnetic flux canceling coil 14 can be controlled remotely from the ground.

When the magnetic flux canceling coil 14 is not energized, the operating core 1 is actuated by the magnetic action of the permanent magnet 11.
2 attempts to electromagnetically adsorb to the gimbal case 6, the center of the magnet support plate 10 is elastically deformed upward, and as a result,
The operating iron core 12 electromagnetically attracts the arc-shaped outer peripheral surface 6b of the gimbal case 6 to brake the movement of the gimbal case 6, and fixes the gimbal case 6 at that position. On the other hand, when the magnetic flux canceling coil 14 is energized, at least a part of the magnetic flux of the permanent magnet 11 is canceled by the magnetic flux generated by the magnetic flux canceling coil 14, so that the magnet supporting plate 10 undergoes elastic deformation. As a result, the operating iron core 12 descends together with the permanent magnet 11 and the upper end surface of the operating iron core 12 separates from the arc-shaped outer peripheral surface 6 b of the gimbal case 6. As a result, the braking force on the gimbal case 6 is released, and free tilt correction movement by the weight 6c of the gimbal case 6 is allowed. As described above, the magnet support plate 10, the permanent magnet 11, the operating iron core 12, and the magnetic flux canceling coil 14 constitute a gimbal case fixing device.

A magnetic fluid reservoir 15 is provided on the upper end surface of the operating iron core 12.
Is formed, and the magnetic fluid reservoir 15 is filled with the magnetic fluid 16 so that the surface of the magnetic fluid 16 is always in contact with the arc-shaped outer peripheral surface 6b. It is possible to achieve centralized operation of the operating iron core 12 efficiently and reliably.

When the seismic sensor 8 is installed in the ground, the seismic sensor 8 is supported via the gimbal case 6 in the pressure vessel, and the pressure vessel supporting the earthquake sensor is lowered into the ground. And install it. When the seismic sensor 8 is supported in the pressure vessel, when the gimbal case 6 is in the most stable state due to the gravity action of the weight 6c, the direction of the reference line of the seismic sensor 8 is predetermined with respect to the vertical line. Are set to form an angle. When the pressure vessel 1 supporting the earthquake sensor 8 is lowered, the magnetic flux canceling coil 14 is not energized, and the gimbal case 6 is fixed to the pressure vessel 1. When the pressure vessel 1 is placed at a predetermined position in the ground, the magnetic flux canceling coil 14 is energized, and the fixing of the gimbal case 6 to the pressure vessel 1 is released. As a result, the gimbal case 6
Is corrected, and the direction of the reference line of the earthquake sensor 8 is directed in a predetermined direction with respect to the vertical direction. When the correction of the inclination of the earthquake sensor 8 is completed, the power supply to the magnetic flux canceling coil 14 is stopped, and the gimbal case 6 is fixed to the pressure-resistant container 1 by the magnetic force of the permanent magnet 11. Even after a large earthquake or when the seismometer is used for a long period of time, when checking the direction of the reference line of the underground seismic sensor, the magnetic flux canceling coil 1 is controlled by controlling the power supply from the ground.
4, the gimbal case 6 is unlocked from the pressure-resistant container 1, and the tilt of the gimbal case 6 is corrected by the gravity action of the weight 6 c.
After automatically correcting the inclination of the direction of the reference line of,
The current supply to the magnetic flux canceling coil 14 is stopped, and the gimbal case 6 is fixed to the pressure-resistant container 1 again.

[0013]

As described above, according to the seismometer inclination correcting apparatus of the present invention, the following effects can be obtained. (1) In a seismometer tilt correction device for correcting the tilt of a seismic sensor supported via a gimbal case in a pressure vessel installed underground, the direction of the reference line of the seismic sensor is perpendicular to the vertical direction. A weight that automatically corrects the tilt of the gimbal case by a gravitational action so as to form a predetermined angle, and usually applies a braking force to the gimbal case to fix the gimbal case to the pressure-resistant container. However, when the braking force is remotely released, the gimbal case is fixed so as to allow a free inclination correction movement of the gimbal case so that the inclination of the gimbal case is automatically corrected by the action of the weight. Correction of the inclination of the seismic sensor when the pressure-resistant vessel with the seismic sensor supported inside is installed underground, or installed underground The correction of the tilt caused by the inspection of the seismic sensor, remotely and conveniently can be performed with high accuracy over a wide angular range than Moreover conventional correctable angular range within a short time (claim 1). (2) The gimbal case fixing device has at least a permanent magnet supported by the pressure-resistant container, and a magnetic flux canceling coil that generates a magnetic flux in a direction to cancel the magnetic flux of the permanent magnet when energized. When the energizing coil was not energized, a braking force was applied to the gimbal case by the magnetic action of the permanent magnet to fix the gimbal case to the pressure-resistant container, and the magnetic flux canceling coil was energized. Sometimes, by canceling at least a part of the magnetic flux of the permanent magnet by the magnetic flux generated by the magnetic flux canceling coil, the braking force on the gimbal case is released, and a free tilt correction movement of the gimbal case is allowed. When a pressure vessel with the seismic sensor supported inside is installed underground, the seismic sensor tilts. And the inclination correction associated with the inspection of the seismic sensor installed in the ground can be performed remotely and within a short period of time using the extremely simple operation of energizing and stopping energizing the magnetic flux canceling coil. It can be performed with high accuracy over an angle range wider than the angle range that can be corrected (claim 2). (3) The gimbal case is supported by the pressure-resistant container via a roller circumscribing an arc-shaped outer peripheral surface centered on the gimbal swing axis of the gimbal case, and the gimbal case fixing device is a permanent gimbal case fixing device. The operating iron core that operates by receiving the magnetic force of the magnet applies the magnetic force to the arc-shaped outer peripheral surface of the gimbal case during braking to brake the gimbal case, and separates from the arc-shaped outer peripheral surface of the gimbal case during non-braking. Movably supported, the operation is reliable, and the correction of the tilt of the seismic sensor can be performed remotely and simply, within a short time, and over a wider angle range than the conventional correctable angle range. It can be performed with high accuracy (claim 3). (4) The upper end surface of the working core is opposed to the lowermost end of the downward arcuate outer peripheral surface of the gimbal case, and the magnetic fluid filled in the magnetic fluid reservoir formed on the upper end surface of the working core is filled with the magnetic fluid. Since it is always in contact with the arc-shaped outer peripheral surface, by concentrating the magnetic flux of the permanent magnet, the inclination of the seismic sensor can be corrected efficiently and reliably. In addition, it can be performed with high accuracy over an angle range wider than the conventional correctable angle range (claim 4).

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a seismometer inclination correcting device according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a main part of the seismometer inclination correcting apparatus according to the embodiment of FIG. 1 as viewed along line AA.

FIG. 3 is a cross-sectional view of the seismometer inclination correction device according to the embodiment of FIG. 1 as viewed along line BB.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pressure-resistant container 2, 3 Partition walls 4a, 4b, 4c, 4d Roller 6 Gimbal case 6a, 6b Arc-shaped outer peripheral surface 6c Weight 8 Earthquake sensor 9a, 9b, 9c, 9d Reinforcement rod 10 Magnet support plate 11 Permanent magnet 12 Operating iron core 13 Through hole 14 Magnetic flux canceling coil 15 Magnetic fluid reservoir 16 Magnetic fluid

Claims (4)

[Claims] 1. A seismometer tilt correction device for correcting the tilt of a seismic sensor supported via a gimbal case in a pressure-resistant container installed underground, wherein the direction of a reference line of the seismic sensor is a vertical direction. And a weight that automatically corrects the inclination of the gimbal case by a gravitational action so as to form a predetermined angle with respect to the gimbal case, and usually applies a braking force to the gimbal case to fix the gimbal case to the pressure-resistant container. However, when the braking force is remotely released, the gimbal case allows a free tilt correction movement of the gimbal case so that the tilt of the gimbal case is automatically corrected by the action of the weight. A seismometer inclination correction device, comprising: a case fixing device. 2. The seismometer inclination correction device according to claim 1, wherein the gimbal case fixing device generates a permanent magnet supported by the pressure-resistant container and a magnetic flux that cancels the magnetic flux of the permanent magnet when energized. A magnetic flux canceling coil, and when the magnetic flux canceling coil is not energized, imparts a braking force to the gimbal case by the magnetic action of the permanent magnet to transfer the gimbal case to the pressure-resistant container. When the magnetic flux canceling coil is energized, the magnetic flux generated by the magnetic flux canceling coil cancels at least a part of the magnetic flux of the permanent magnet, thereby reducing the braking force on the gimbal case. Characterized in that it is configured to release the gimbal case and to allow free tilt correction movement of the gimbal case. Positive device. 3. The seismometer inclination correcting device according to claim 2, wherein the gimbal case is provided by the pressure-resistant container via a roller circumscribing an arc-shaped outer peripheral surface centered on a gimbal swing axis of the gimbal case. An operating iron core, which is supported and operates by receiving the magnetic force of the permanent magnet constituting the gimbal case fixing device, brakes the gimbal case by applying magnetic force to the arc-shaped outer peripheral surface of the gimbal case during braking. And a seismometer inclination correction device, which is movably supported so as to be separated from the arc-shaped outer peripheral surface of the gimbal case when braking is not performed. 4. The seismometer inclination correcting apparatus according to claim 3, wherein an upper end surface of the working core faces a lowermost end of a downwardly arcuate outer peripheral surface of the gimbal case, and an upper end of the working core. A magnetic fluid filled in a magnetic fluid reservoir formed in a surface portion is always in contact with the arc-shaped outer peripheral surface, wherein the inclination correction device for seismometers is provided.