JP2913525B2 - Inclinometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inclinometer and, more particularly, to an inclinometer for determining an inclination angle from the horizontal with high accuracy by knowing the direction of acceleration of gravity on the ground.

[0002]

2. Description of the Related Art A non-servo inclinometer using a strain gauge or a differential transformer is used as an inclinometer for measuring ground movement and inclination of a building, and a force for detecting displacement and making the displacement zero. There is a servo-type inclinometer that is generated and calculates an inclination angle with the required force.

FIG. 10 is a cross-sectional view schematically showing a configuration of an example of a conventional servo inclinometer, in which a method of supporting a movable plate by a tote band is employed. This FIG.
Reference numeral 1 denotes a holder, and a lower case 2a of a case 2 divided into upper and lower parts is attached to the holder 1, and a bellows 3 is provided between the upper and lower cases 2a and 2b.
Are linked by

A block 4 is mounted on the holder 1, and the block 4 is provided with a groove 4a.
A plate-shaped weight 5 is suspended in the groove 4a. In the position of the block 4 facing the lower end of the weight 5,
A photo interrupter (not shown) is built in.

[0005] The upper portion of the weight 5 is attached to the outer periphery of the coil 6. The coil 6 is wound around an annular bobbin 7, and a permanent magnet 8
Are arranged at appropriate intervals. This permanent magnet 8
An annular yoke 9 is disposed so as to oppose the north pole and the south pole of the bobbin 7 at a small distance from the outside of the bobbin 7. A lower end of the yoke 9 is fixed to the block 4, and a block 10 is mounted and fixed to an upper end of the yoke 9. The permanent magnet 8 is fixed to the yoke 9 at one end.

[0006] At both ends of the block 10, electrodes 11a and 11b having a spring property are attached. Both ends of the coil 6 are connected to lower ends of the electrodes 11a and 11b via ribbons 15a and 15b, and are supported in a suspended state.

The output of a servo amplifier (not shown) is applied to the electrodes 11a and 11b. The output of the photo interrupter is input to an input terminal of the servo amplifier. Reference numeral 12 denotes silicone oil filled in the case 2.

Next, the operation of this conventional servo inclinometer will be described. The inclinometer of FIG. 10 is installed at a predetermined location to be measured, and if there is no inclination at the location to be measured, the block 4 together with the holder 1 is stationary. Therefore, the weight 5 is located at the center of the two light receiving elements of the photo interrupter in the groove 4a of the block 4, and the light from the light emitting element is equally incident on the two light receiving elements, and the weight from the servo amplifier. No output. As a result, no force is generated on the yoke 9 to return the coil 6 to its original position.

Next, when the position to be measured is inclined, the blocks 4, 10 and the yoke 9 are rotated together with the holder 1 according to the degree of the inclination. In accordance with the amount of rotation, the position of the weight 5 with respect to the photo interrupter changes, and the difference between the luminous flux generated from the light emitting element of the photo interrupter and entering the two light receiving elements gradually increases. The two outputs are input to the servo amplifier.

The servo amplifier feeds back a current necessary for returning the relative position of the coil 6 to the yoke 9 to the original position to the coil 6 according to the difference between the two input levels. By converting this current into a voltage using a resistor or the like, the amount of inclination (inclination angle) of the measured location can be known.

[0011]

However, in such a conventional servo type inclinometer, since the rigidity in the direction other than the sensitivity direction is low, the silicon oil is enclosed in the space surrounded by the case 2, the bellows 3, and the holder 1. Care must be taken that the silicon oil 12 does not apply a sudden force to the blocks 4, 10, the bobbin 7, the coil 6, the weight 5, and the like.

Filling with such a silicone oil 12 or the like increases dimensions and also requires a seal or the like, resulting in an increase in manufacturing cost.

In addition, a damping oil such as the silicone oil 12 has a drawback that the bellows 3 must be used because the expansion and shrinkage due to heat is large, and the manufacturing cost is also increased in this respect. Also, the ribbon 15
Because of the use of a and 15b, they are mechanically vulnerable to impact or the like.

On the other hand, in a conventional servo-type accelerometer, a movable plate and a flexible portion of a pendulum structure have an integral structure.
Since the flexible part is processed by electric discharge machining or etching,
The thickness is limited to a maximum of 20 μm to 30 μm.

[0015] Therefore, each component requires extremely high precision processing.

Also, very high precision is required for the drift of the servo amplifier.

Attempts have been made to use a thin foil for the flexible part. However, when screwing or riveting is employed, the tightening force cannot be kept constant for a long time, and the stability and other performances are poor. Bad, I couldn't get anything to reach my goal.

The present invention has been made in view of the above circumstances, and its object is to provide an inexpensive, small-sized, robust device.
In addition, it is an object of the present invention to provide an inclinometer having a very wide range of applications that can be used for ground deformation, seismometers, vibration measurement, accelerometers, etc., with very little change with time and high accuracy.

[0019]

According to a first aspect of the present invention, there is provided an image forming apparatus, comprising: a metal fixing plate fixed to a main body; A pair of magnetic circuits mounted in an electrically insulated state, wherein the pair of opposing surfaces are formed of a conductor and have a predetermined gap between the opposing surfaces; And an ultra-thin flexible plate having an upper end fixed to the fixed plate, a movable plate having an upper end fixed to the lower end of the flexible plate and suspended in the gap, and symmetrically on both sides of the movable plate. And a pendulum structure having a coil mounted and disposed in the magnetic structure.

Further, the invention according to claim 2 is characterized in that the movable plate and the bobbin around which the coil is wound are made of any one of aluminum alloy, titanium alloy and magnesium alloy.

The invention according to claim 3 is characterized in that the flexible plate is made of any one of spring materials such as beryllium copper, titanium alloy, stainless steel for spring, and spring steel.

According to a fourth aspect of the present invention, at least one of the movable plate and the flexible plate is formed of ceramic or glass, and at least a portion thereof is formed with a metal thin film such as chrome-gold or aluminum. It is characterized by.

According to a fifth aspect of the present invention, in the state where the upper end of the flexible plate is sandwiched between the fixed plate and the holding plate, a U-shaped clip member is formed from the outer surfaces of the fixed plate and the holding plate. The flexible plate is fixed to the fixed plate by pressing, and the lower part of the flexible plate is sandwiched between the upper part of the movable plate and the presser plate, and a U-shape is formed from the outer surfaces of the movable plate and the presser plate. It is characterized by being fixed to the movable plate by pressing with a clip member.

[0024]

In the inclinometer configured as described above, the movable plate fixed to the fixed plate integral with the main body via the flexible plate is provided in the gap between the opposing surfaces of the two magnetic structures. When the part to be measured has no inclination at the part to be measured, the capacitance of the movable plate and the opposing surface of the magnetic structure are balanced, but when the part to be measured is inclined, the fixed plate is inclined in the inclination direction. As a result, the movable plate is displaced relative to the fixed plate, and the distance between the movable plate and the opposing surface of the magnetic structure changes, thereby causing a change (unbalance) in the capacitance between them.

In accordance with this change, the current flowing through the coils mounted on both sides of the movable plate changes, and current flows through the coil so that the movable plate returns to its original position with respect to the magnetic structure. This current value is proportional to the force applied to the movable plate, and if the inclination angle is θ, it is proportional to sin θ, so that the inclination angle can be known.

Further, since the movable plate and the bobbin are formed of light metal, the weight can be reduced. Further, by disposing the movable plate in the minute gap between the two opposed surfaces of the two magnetic structures, when the movable plate is excessively displaced when the tilt occurs, the opposed surfaces of the magnetic structure are displaced. Serves as a stopper for the movable plate, thereby preventing damage to the movable plate, and further increasing the resonance frequency, thereby making it less likely to be affected by the vibration frequency of the portion to be measured.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing the overall configuration of one embodiment of an inclinometer according to the present invention.

In FIG. 1, reference numeral 21 denotes a main body serving as a disk-shaped fixing plate, and a notch hole 21a for disposing opposed yokes 24a and 24b, which will be described later, is provided at an intermediate portion in the vertical direction. Are drilled. An outer peripheral surface near the lower end of the main body 21 is fitted with a case 22 having a cylindrical shape and made of an aluminum alloy for weight reduction.

As shown in FIG. 3, a printed circuit board 23 is mounted on the top plate 21b of the main body 21 through a plurality of conductive pins 23a above the case 22, as shown in FIG.
Necessary electric circuit components are mounted on the printed circuit board 23. As is clear from FIGS. 1 and 3, a pair of yokes 24a,
24b is fixed to the main body 21 via insulators 25a and 25b.

The yokes 24a and 24b are formed of mild steel, and, as is evident from FIG. 1, have bottomed portions having flanges 24a1 and 24b1 on the side periphery symmetrically with respect to the axis of the case 22. It is formed in a cylindrical shape. The flange portions 24a1, 24 on the open end sides of the yokes 24a, 24b.
b1 is a ring-shaped insulator 2 such as a ceramic.
5a and 25b are joined, and the insulators 25a and 25b
5b is fixed by screws (not shown) in a state where the inner peripheral surface is joined to the outer peripheral surface of the lower part of the upright column 27 of the main body 21. Thus, the flange portions 24a1 and 24b1 of the yokes 24a and 24b are fixed to the upright pillar 27, that is, the main body 21.

The inner end surfaces of the yokes 24a and 24b have opposing surfaces that oppose each other at a predetermined minute interval, and the opposing surfaces serve as electrodes 24a2 and 24b2 of the capacitor, respectively.

Rare earth magnets 28a, 28b are mounted on the inner surfaces of the centers of the yokes 24a, 24b, and the N poles of the rare earth magnets 28a, 28b are mounted so as to face each other. That is, the magnetic poles are the same. These rare earth magnets 28a,
At the inner end of 28b, that is, the N pole, a pole piece 29
a, 29b are attached.

Thus, the yoke 24a, the rare earth magnet 2
8a and the pole piece 29a form one magnetic structure. Similarly, the other magnetic structure is formed by the yoke 24b, the rare-earth magnet 28b, and the pole piece 29b. That is, two sets of magnetic structures are arranged symmetrically with respect to the axis of the case 22.

On the other hand, a metal holder 30 is formed at the upper end of the upright column 27 integral with the main body 21. A fixing plate 31 is fixed to one surface of the holder 30 by mounting screws 32. A flexible plate 3 is provided below the fixed plate 31.
3 is fixed.

The fixed portion between the fixed plate 31 and the flexible plate 33 is shown enlarged in FIG. FIG. 2 is an enlarged sectional view of a portion indicated by a circle A in FIG. 1, and FIG. 4 is a plan view showing a state where the flexible plate 33, the fixed plate 31, and a movable plate 36 described later are connected. .

These FIGS. 1, 2 and 4 and FIG.
As is clear from FIG. 5, the vicinity of the upper end of the flexible plate 33 is sandwiched between one surface of the fixed plate 31 and the holding plate 34.
The fixing plate 31 and the pressing plate 34 are pressed against each other by a U-shaped clip member 35 as shown in FIG. As is clear from FIGS. 3 and 4, the clip member 35
The fixing plate 31 and the holding plate 34 are press-fitted from both end edges of the outer surfaces thereof and strongly pressed by a spring force.

In this case, the flexible plate 33 is made of a spring material such as beryllium copper, titanium alloy, stainless steel for spring, or spring steel, and has a thickness of 5 to 15 μm.
m, and has sufficient flexibility.

The clip member 35 is formed of a spring material such as beryllium copper, stainless steel for spring, adjacent bronze, spring steel, etc., and as is apparent from FIGS.
Since it is formed in a U-shape, its opposite sides 35
It has spring properties in the directions a and 35b.

Therefore, the outer surface of the fixed plate 31 holding the flexible plate 33 and the outer surface of the holding plate 34 are fixed to the clip member 3 by using a jig.
5 only by press-fitting the flexible plate 33 with its strong spring clamping force.
The flexible plate 33 can be easily connected and fixed to the fixed plate 31 without performing high-precision drilling on the fixed plate 31 and the flexible plate 33.

The connection and fixing of the flexible plate 33 and the movable plate 36 are performed in exactly the same manner, and the vicinity of the lower end of the flexible plate 33 is sandwiched between the vicinity of the upper end of the movable plate 36 and the holding plate 34. Then, a U-shaped clip member 35 similar to the above is press-fitted from the outside, and the flexible plate 33 is crimped between the movable plate 36 and the holding plate 34 by the clip member 35 as shown in FIG.

By doing so, the flexible plate 33
Is fixed at a very small interval between the fixed plate 31 and the movable plate 36. As is clear from FIG. 4, it can be seen how the size of the flexible portion of the flexible plate 33 fixed between the fixed plate 31 and the movable plate 36 is smaller than the length of the fixed plate 31 and the movable plate 36.

The upper end of the movable plate 36 is connected and fixed to the fixed plate 31 via the flexible plate 33 so that the movable plate 3
6 is in a state of hanging down by the gravity.
The movable plate 36 is inserted between the electrodes 24a2 and 24b2 of the yokes 24a and 24b, as is clear from FIG. The movable plate 36 is formed of, for example, a light metal such as an aluminum alloy, a titanium alloy, or a magnesium alloy.

Therefore, the movable plate 36 is
a2 and 24b2 serve as common electrodes of the capacitors, respectively.
When the electrode is excessively displaced in either direction of the 4a2 side or the 24b2 side, the displaced electrode acts as a displacement stopper, and as described above, the movable plate 36 is made of light metal and lightweight. Therefore, the damage caused by the collision is deviated.

As is clear from FIG. 1, ring-shaped bobbins 37a and 37b are provided on both surfaces of the movable plate 36 near or near the electrodes 24a2 and 24b2, respectively, integrally or integrally with the movable plate 36. I have.

The bobbins 37a and 37b are wound with coils 38a and 38b, respectively. Coil 38
a, 38b, the pole pieces 29a, 2 respectively.
9b is inserted. In this way,
Fixed plate 31, flexible plate 33, movable plate 36, bobbin 37a,
A pendulum structure is constituted by 37b and coils 38a and 38b.

FIG. 6 is a block diagram showing a displacement detection and damping circuit of the inclinometer of the present invention constructed as described above. In the inclinometer, the same parts as those in FIG. Only.

In FIG. 6, the yokes 24a, 24b
, That is, the electrodes 24a2 and 24b2 are connected to the input terminals of the servo amplifier 39, respectively. The servo amplifier 39 is supplied with operating power which is stabilized by a voltage stabilizing circuit and a protection circuit 40 from the power supply terminals T1 to T3.

One output terminal of the servo amplifier 39 is connected to, for example, a coil 38a, and the other output terminal of the servo amplifier 39 is connected to a coil 38b via a current detecting resistor 41.

The resistor 41 allows a current flowing on the coil 38b side, that is, a detection current according to the displacement of the movable plate 36 to flow. The voltage across the resistor 41 is
The signal is led to output terminals T4 and T5 via a filter 42. The filter 42 is a low-pass filter for removing a vibration component such as a part to be measured included in the tilt detection signal. The signal passing through the filter 42 is extracted from the output terminals T4 and T5 as a tilt detection signal. Has become.

Next, the operation of this embodiment configured as described above will be described. This inclinometer will be described as being installed at a site to be measured and detecting an inclination angle. When the inclinometer is tilted to the left most on the plane of FIG. 1, the movable plate 36 does not move in the vertical direction, but the main body 21 is tilted, so that the movable plate 36 is relatively displaced to the left accordingly. Accordingly, the flexible plate 33 bends.

As a result, the space between the movable plate 36 and the electrode 24b2 is reduced, and the space between the movable plate 36 and the electrode 24a2 is opened. At this time, the capacitance between the movable plate 36 and the electrode 24a2 decreases, and conversely, the capacitance between the movable plate 36 and the electrode 24b2 increases.

Therefore, the change in the capacitance is differentially amplified by the servo amplifier 39 shown in FIG. 6, and a current flows from the output terminal of the servo amplifier 39 to the coils 38a and 38b. Since these coils 38a and 38b are wound so as to be orthogonal to the magnetic flux in the magnetic circuit by the yokes 24a and 24b and the rare earth magnets 29a and 29b, respectively, they are proportional to the current flowing through the coils 38a and 38b. Force is received by the coils 38a, 38b.

By selecting the direction of the current flowing through the coils 38a and 38b in such a manner that the distance between the movable plate 36 and the electrode 24a2 and the distance between the movable plate 36 and the electrode 24b2 become equal.
Between the movable plate 36 and the electrode 24a2, between the movable plate 36 and the electrode 24b
The distance between the two can always be kept constant, the current flowing at that time being proportional to the force applied to the pendulum structure.

Now, assuming that the inclination angle is θ and the mass of the pendulum structure is m, the force applied to the pendulum structure is m · g · sin
Since θ is the acceleration of gravity, the inclination angle θ can be obtained from the value of the flowing current. That is, this current value is converted into a voltage across the current detection resistor 41,
The voltage at both ends of the resistor 41 is filtered out of the vibration component by the filter 42 and can be taken out from the output terminals T4 and T5 as a current value corresponding to the tilt angle θ.

By the way, the interval between the movable plate 36 and the electrode 24a2 becomes larger than the interval between the movable plate 36 and the electrode 24b2 due to the temperature gradient, or the servo amplifier 39
In the case where the capacitance of one side is measured slightly larger due to the drift, the movable plate 36 is controlled to a position slightly different from the original position.

At this time, if the spring constant of the flexible plate 33 is zero, no error occurs, but it is not actually zero, so the reaction force of the flexible plate 33 required to return the movable plate 36 to its original position. Minutes are errors. Since the spring constant of the flexible plate 33 is proportional to the cube of the thickness t, in the case of the present embodiment in which the thickness is 1/2 to 1/4 of the conventional thickness, this error is reduced to 1/8 to 1 / It can be reduced to 64.

As described above, in the present invention, the reaction force is reduced by making the flexible plate 33 as thin as possible (5 to 15 μm). Processing becomes simple and it can be inexpensive.

In FIG. 1, the movable plate 36 is soft to the left and right in the plane of the paper and swings with a slight force, but is made rigid against the forces from the top and bottom and from the back to the front of the paper. Furthermore, it is made rigid against torsion, and even if external vibration is applied, the movable plate 36 does not become uncontrollable due to vibration other than the control direction.

Therefore, by adding a damping signal to the control signal, resonance can be suppressed, and there is no need to fill a damping fluid, for example, silicon oil, as in the conventional case. Such a bellows can be eliminated, the seal can be simplified, and the bellows can be provided at low cost.

As described above, according to this embodiment, the movable plate 36 connected and fixed to the fixed plate 31 via the extremely thin flexible plate 33 in the pair of symmetrical magnetic structures. The coils 38a, 38b are mounted on both surfaces of the movable plate 36 so as to be orthogonal to the magnetic flux of the magnetic structure to form a pendulum structure, and a pair of electrodes 24a2, 2 of the magnetic structure are provided.
The movable plate 36 is suspended between the electrodes 24a2 and 2b2.
Coil 3 so that the displacement of movable plate 36 between
Since the current flows through the coils 8a and 38b, the inclination angle can be known from the current flowing through the coils 38a and 38b.

Since the magnetic structure is symmetrical, it is stable against temperature changes, and the movable plate 36 is made of a light metal such as an aluminum alloy. In addition to the above, the size and weight can be reduced, and there is no fear that the electrodes 24a2 and 24b2 may be damaged even if they collide with the electrodes 24a2 and 24b2.

Further, since the displacement of the movable plate 36 is very small and the connection between the flexible plate 33 and the fixed plate 31 or the movable plate 36 is strong, there is no creep or hysteresis of the flexible plate 33 and high precision. Can be achieved.

Since the flexible plate 33 can also be made extremely thin, there is little change in output due to distortion of the mechanical part or drift of the amplifier. In addition, since there are few sophisticated precision processing parts, the processing cost can be reduced. In addition, the magnetic structure has high rigidity in directions other than the sensitivity direction and forms a closed magnetic circuit that is strong against vibration and impact. Therefore, the magnetic structure is hardly affected by an external magnetic field and, conversely, has little influence on the outside.

On the other hand, the case 22 is made of an aluminum alloy or the like to reduce its weight and to seal nitrogen gas inside so as to protect it against aging. Aging characteristics can be obtained. FIG. 9 shows the change with time near the horizontal as a percentage of the rated output.

In addition, as a usage form, the apparatus is generally used vertically, but it can be used upside down and horizontally, and the difference between the measured value and the theoretical value with respect to the inclination angle in this case is used. 7 and 8 show the percentage of the rated output with respect to the rated output, and the non-linearity is 0.01 to 0.03% R
O, hysteresis is 0.015-0.025% RO,
The difference in rated output between postures is 0.1% RO. Note that FIG. 7 shows the case of the inverted installation, and FIG. 8 shows the case of the horizontal installation.

As is apparent from the above description, the present invention can detect inclination, so that it can be used as an inclinometer for measuring the inclination of the ground or building due to the ground deformation, as well as the seismic measurement. Needless to say, it can also be used as an accelerometer for measuring vibration and vibration.

The present invention is not limited to the above embodiment, but can be variously modified without departing from the scope of the invention.

[0068]

As described above in detail, according to the first aspect of the present invention, the movable plate is connected to the fixed plate via the extremely thin flexible plate, and a pair of magnetic structures opposed to each other. A coil wound perpendicular to the direction of the magnetic flux of the magnetic component is attached to the movable plate, and the movable plate and the magnetic structure are displaced when the movable plate is relatively displaced due to the inclination. The movable plate is returned to the original position by changing the amount of electricity to the coil according to the change in the capacitance between the opposing surfaces, so that the tilt angle can be detected from the current flowing through the coil at that time. The configuration makes the inclinometer small, lightweight, highly sensitive and highly accurate. In particular, since the flexible plate has an extremely thin plate shape, the lateral sensitivity is small, and the inclinometer has excellent vibration and impact resistance. .

According to the second aspect of the present invention, since the movable plate is made of light metal, there is no danger that the movable plate will be damaged even when the displacement is large, and the resonance frequency of the movable plate is reduced. As the height increases, the effect of vibration (disturbance) at the inclinometer installation site is deviated, and detection accuracy is improved.
By adding a damping signal to a coil by a control signal, resonance can be suppressed, and the inclinometer can be provided which does not require filling with a damping oil or the like and sealing thereof, thereby reducing costs accordingly.

According to the third aspect of the present invention, since the flexible plate is formed of a spring material, it is excellent in resilience, excellent in the function of returning the movable plate to its original position after displacement, and highly accurate inclining. An inclinometer that can indirectly contribute to angle detection can be provided.

According to the fourth aspect of the present invention, by forming at least one of the movable plate and the flexible plate with ceramic or glass, the coefficient of linear expansion with the mild steel which is the main constituent of the magnetic structure is reduced. The gap between the opposing surfaces of the movable plate and the magnetic structure does not fluctuate due to temperature changes, the tilt angle can be detected with high accuracy, and a metal thin film is formed on the surface. Therefore, it is possible to provide an inclinometer which does not impair the function as an electrode of a capacitor formed between the magnetic structure and the opposing surface.

According to the fifth aspect of the present invention, the upper and lower portions of the flexible plate are pressed between the pressing plate and the fixed plate, and between the pressing plate and the movable plate by the U-shaped clip member having a spring property. As a result, the flexible plate is always connected and fixed to the fixed plate and the movable plate with a constant force, and the fixed state does not change. Therefore, it is possible to provide an inclinometer capable of improving the load characteristics and the temperature characteristic creep characteristics of the inclinometer without any error in the detection output.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an entire configuration of an embodiment of an inclinometer according to the present invention.

FIG. 2 is an enlarged sectional view showing a fixed state of a flexible plate in the embodiment of FIG.

FIG. 3 is a front view of the case of the embodiment of FIG. 1 cut away.

FIG. 4 is a front view showing a state where the flexible plate in the embodiment of FIG. 1 is connected and fixed to a fixed plate and a movable plate.

FIG. 5 is a perspective view showing a configuration of a clip member used for fixing the flexible plate in the embodiment of FIG. 1;

FIG. 6 is an explanatory diagram for explaining the operation principle of the embodiment of FIG. 1;

FIG. 7 is a characteristic diagram showing a difference between a measured value and a theoretical value with respect to an inclination angle in a case where the embodiment of FIG. 1 is installed in an inverted posture and used as a percentage with respect to a rated output.

FIG. 8 is a characteristic diagram showing a difference between a measured value and a theoretical value with respect to an inclination angle in a case where the embodiment of FIG.

FIG. 9 is a characteristic diagram showing a change over time in output near the horizontal in the example of FIG. 1 expressed as a percentage of a rated output.

FIG. 10 is a cross-sectional view schematically showing a configuration of a conventional inclinometer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 Main body part 22 Case 23 Printed circuit board 24a, 24b Yoke 24a2, 24b2 Electrode 24a1, 24b1 Flange part 25a, 25b Insulator 27 Standing pillar 28a, 28b Rare-earth magnet 29a, 29b Pole piece 30 Holder 31 Fixing plate 32 Mounting screw 33 Possible Flexible plate 34 Holding plate 35 Clip member 36 Movable plate 37a, 37b Bobbin 38a, 38b Coil

Claims (5)

(57) [Claims] 1. A metal fixing plate fixed to a main body,
A pair of magnetic circuits attached to the main body in an electrically insulated state so that opposing surfaces have the same magnetic pole, wherein the pair of opposing surfaces is formed of a conductor, and , Two magnetic structures having a gap at a predetermined interval, an extremely thin flexible plate having an upper end fixed to the fixed plate, and an upper end fixed to the lower end of the flexible plate and suspended in the gap. An inclinometer comprising: a pendulum structure having a movable plate and coils symmetrically mounted on both sides of the movable plate and disposed in the magnetic structure. 2. The inclinometer according to claim 1, wherein the bobbin around which the movable plate and the coil are wound is made of any one of aluminum alloy, titanium alloy, and magnesium alloy. 3. The inclinometer according to claim 1, wherein the flexible plate is made of any one of spring materials such as beryllium copper, titanium alloy, stainless steel for spring, and spring steel. 4. The apparatus according to claim 1, wherein at least one of the movable plate and the flexible plate is formed of ceramic or glass, and at least a part thereof is formed with a thin metal film such as chrome-gold or aluminum. The inclinometer according to 1. 5. The flexible plate is pressed against an outer surface of the fixing plate and the holding plate by a U-shaped clip member while holding an upper end portion of the flexible plate between the holding plate and the holding plate. While being fixed to the fixed plate, the lower portion of the flexible plate is pressed between the upper surface of the movable plate and the holding plate with a U-shaped clip member from the outer surfaces of the holding plate and the holding plate. The inclinometer according to claim 1, wherein the inclinometer is fixed to the movable plate.