JPH083418B2 - Inclination measuring device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a tilt angle measuring device that is attached to an object to be detected and measures the tilt angle thereof.

(Prior Art) As a conventionally known tilt angle measuring device, there is one as shown in FIG. In this system, a liquid 52 is placed in a container 51, and a disk 53 is rotatably attached to a shaft 56 attached to the container 51 via a bearing bearing 57. Since the float 54 and the weight 55 are attached to the outer peripheral portion of the disk 53 so as to face each other with respect to the center thereof, the disk 53 is in the liquid 52 in the container 51, and the float 54 and the weight 55 must be used. It is designed to stand still at a fixed reference position. Further, as shown in the figure, the disk 53 is provided with slits 60 that extend in different directions in the circumferential direction on several different radii, and the container 51 sandwiches the slits 60 and emits light. The light receiving part 59 and the light receiving part 59 are attached to face each other. Light emitting elements corresponding to the positions where the slits 60 are formed are sequentially arranged in the light emitting portion 58, and light receiving elements facing the light emitting elements are sequentially arranged in the light receiving portion 59. Therefore, an output corresponding to the rotation angle of the disk 53 with respect to the container 51 is obtained from the light receiving unit 59, and the inclination angle of the container 51 can be detected from this output.

However, in this conventional inclination angle measuring device, the disk 53 may not rotate when the inclination angle is small due to the starting friction in the bearing bearing 57, and it is not possible to measure a minute inclination. is there. Starting friction in this bearing 57 and its sliding friction, and disc
Due to the sliding friction between 53 and the liquid 52, the output V of the light receiving portion 59 with respect to the inclination angle θ ₁ is the output V _a obtained when θ is increased, as shown in FIG. There is also a problem that _a difference ΔV (= V _b −V _a ) is generated between the output V _b and the output V _b obtained when the size is reduced, and an accurate tilt angle cannot be measured.
Further, as shown in FIG. 8, when the container 51 is inclined in the extending direction of the shaft 56, the magnitude of the force acting on the bearing bearing 57 becomes uneven, so that the friction becomes large and the disk 53 rotates. There is also a problem that it becomes difficult to do so and measurement becomes difficult.

(Problems to be Solved by the Invention) Therefore, an object of the present invention is to eliminate the drawbacks of the above-described conventional tilt angle measuring device and to accurately measure the tilt angle without deterioration of measurement accuracy due to friction of the movable member. It is an object of the present invention to provide a novel tilt angle measuring device capable of performing the above.

(Means for Solving the Problems) In FIG. 1, the inclination angle measuring device of the present invention is a container 3
And a liquid 2 is contained therein, and a magnet 14 having at least two adsorption points located on a straight line is arranged at the bottom of the container 3, and the lower end 8A of the rocking member 5 is a magnet.
It is adsorbed at 14 adsorption points, and the float 10 is attached to the upper end portion thereof, and it receives the buoyancy of the liquid 2 and swings about the adsorption point as a fulcrum in a direction orthogonal to the above-mentioned straight line direction and is always held in a vertical state. The light source 20 that makes the light incident on the light reflecting surface 6 attached to the swing member 5 and the light receiving portion 30 that receives the reflected light from the light reflecting surface 6 and detects the displacement of the light receiving point. And are integrally attached to the container 3.

(Operation) When the container 3 is tilted, the oscillating member 5 oscillates with the suction point serving as a fulcrum by the action of the buoyancy of the float 10, and becomes vertical and stands still. Therefore, the light reflecting surface 6 also always makes a constant angle with respect to the vertical line, but the light source 20 integrated with the container 3 is inclined with respect to the vertical line, so that the light receiving point incident on the light receiving section 30 from the light reflecting surface 6 is The position is displaced according to the tilt angle. The inclination angle of the container 3 can be obtained from this displacement amount.

(Example) The Example of this invention is described using attached FIGS.

1 and 2, a container 3 containing a liquid 2 is fixed in the device body 1 of the tilt angle detecting device of the present invention, and the container 3 is tilted in the container 3 as shown in FIG. The swing member 5 is provided so as to swing in the direction of the arrow 4 shown in FIG. Rocking member 5
Has a reflector plate 6, and the reflector plate 6 has a pair of support pillars 8 of which at least tips 8A are made of a magnetic material at both side edges thereof.
It is fixed to and the float 10 is attached to the upper ends of the columns 8 and 8.
Is installed. On the other hand, at the bottom of the container 3, a guard stand 12 made of, for example, a synthetic resin and made of a non-magnetic material is arranged. Inside the guard stand 12, a columnar permanent body having a length slightly longer than the distance between the columns 8 is provided. The magnet 14 is embedded.
The tip 8A of the column 8 is inserted into the guard base 12 and a pair of holes 16 for supporting the same is formed. The tip of the hole 16 reaches the magnet 14 embedded in the guard base 12. Has been extended to. The tip 8A of the column 8 is formed in a pointed shape and is adapted to engage with the hole 16 in a loosely fitted state. The tip 8A is attracted to the magnet 14 in the hole 16,
The swinging member 5 swings with respect to the container 3 with the suction point serving as a fulcrum. Since the float 10 provided on the top of the swing member 5 is always located directly above the suction point in the vertical direction, the reflector 6 is always in the vertical state. In addition,
In FIG. 1, the rocking member 5 may separate from the magnet 14 and levitate upward when an external force such as vibration is applied to the tilt angle detecting device. _{By making 2} smaller than the depth d ₁ of the hole 16 of the guard base 12, it is possible to prevent the swinging member 5 from falling out of the hole 16.

Inside the device body 1 outside the container 3, a light source 20, a collimation lens 22, and a slit 24 are arranged in series,
The parallel light having a slit-shaped cross section that passes through the slit 24 is projected onto the reflection plate 6 through the glass window 3A formed in a part of the container 3. Another reflecting plate 7 is attached to the inner wall surface of the container 3 facing the reflecting plate 6, and the parallel light passing through the slit 24 first enters the reflecting plate 6 as shown in FIG. The reflected light is incident on the reflecting plate 7, the reflected light is reflected again by the reflecting plate 6, and is received by the light receiving section 30 via another glass window 3B of the container 3. Therefore, when the device body 1 is tilted by the tilt angle θ, the reflector 6 is tilted relative to the reflector 7 by the angle θ, and the slit light 31 incident on the light receiving unit 30 is tilted by 4θ by the law of reflection. The slit light 31 moves from the reference position by a distance d (see FIG. 3) according to the angle deflection.

As shown in FIG. 3, the light-receiving unit 30 is composed of a pair of right-angled triangular light-receiving elements 30A and 30B arranged on a light-receiving plane so as to be a rectangular shape as a whole at a predetermined distance. The slit light 31 is received by the light receiving elements 30A and 30B, and the voltages U ₁ and U ₂ proportional to the areas A ₁ and A ₂ of the irradiation portion are output.

The outputs U ₁ and U ₂ of the light receiving elements 30A and 30B are amplified by the amplifier circuits 32 and 34 to V ₁ and V ₂ , respectively, as shown in FIG. 4, and these outputs V ₁ and V ₂ are subtraction circuits. 36 and the adder circuit 38 are connected to the respective two inputs. The subtraction circuit 36 outputs an output difference (V ₁ −V ₂ ), and this output is converted from a voltage to an angle by the voltage-angle conversion circuit 40 so that the angle is displayed on a display unit (not shown). Has become. Third
In the figure, the light receiving elements 30A, 3
If the area of 0B is A ₁ and A ₂ , the output obtained from them is
Since U ₁ and U ₂ are proportional to the areas A ₁ and A ₂ , U ₁ + U ₂ = U (constant), and therefore V ₁ + V ₂ = V (constant), so V ₁ and V ₂ are If one increases, the other decreases. Then, from the output (V ₁ −V ₂ ) of the subtraction circuit 36,
The distance d of the slit light 31 from the central position l _{1 in} the longitudinal direction of 30 is found, and d is proportional to the tilt angle θ of the apparatus main body 1, and thus the tilt angle θ is found.

On the other hand, the adder circuit 38 always calculates the combined output (V ₁ + V ₂ ), and the combined output is connected to the comparison circuit 42, and the comparison circuit 42 compares the reference voltage with the combined output (V ₁ + V ₂ ). The comparison output is connected to a current control circuit 43 that adjusts the light amount of the light source 20. The circuit system including the adder circuit 38, the comparison circuit 42, and the current control circuit 43 keeps the voltage (V ₁ + V ₂ ) constant. That is, the total output (V ₁ + V ₂ ) of the light receiving unit 30 by the slit light 31 should always be a constant value, but the light amount of the light source 20 changes due to changes in the outside air temperature, etc. The output (V ₁ + V ₂ ) may change, but by using the circuit system including the adder circuit 38, the comparison circuit 42, and the current control circuit 43, the light source
The light quantity of 20 can be made constant regardless of changes in the outside temperature. For example, when the outside air temperature rises,
When the amount of light from 20 increases and the total output (V ₁ + V ₂ ) increases and becomes higher than the set reference voltage, the current supplied to the light source 20 is reduced by the above-mentioned circuit system composed of 38, 42, 43. The amount of light decreases, and the total output (V ₁ + V ₂ ) of the light receiving section 30 is always equal to the set reference voltage. Therefore, for example, the present apparatus can be used regardless of changes in the outside air temperature.

In the swing member 5 of the above embodiment, the reflecting mirror 6
The supporting member 8 is supported by the two supporting columns 8 and 8. However, in the swing member 5'of another embodiment shown in FIG. 5, the reflecting plate 6 is supported by the supporting column 28 in the form of a flat plate. Good. In this case, the pointed tip 28
The hole of the guard stand 12 (FIGS. 1 and 2) into which A is inserted and supported must be a groove extending in a V-shaped cross section, instead of the hole 16 in the above embodiment.

Further, in the embodiment shown in FIGS. 1 to 4, the slit light from the light source 20 is reflected by the reflecting mirrors 6 and 7 three times and received, but if the number of times of reflection is further increased, the tilt angle .theta. The displacement amount d of the light receiving point with respect to is increased, and the measurement accuracy can be improved.

Although several embodiments of the present invention have been described above, it will be apparent to those skilled in the art that various other modifications are possible.

(Effect of the Invention) Since the inclination angle measuring device of the present invention does not cause any friction with the rotation of the swinging member, it is possible to accurately measure even a small inclination, and as shown in FIG. As described above, it is possible to always measure an accurate tilt angle without showing different values for the same tilt angle depending on whether the tilt angle is increased or decreased.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a first embodiment of the tilt angle measuring device of the present invention, FIG. 2 is a vertical sectional view taken along the line II-II in FIG. 1, and FIG.
FIG. 4 is a front view of the light receiving part, FIG. 4 is a circuit diagram of the light receiving part, FIG. 5 is a perspective view of a swing member of another embodiment, and FIG. 6 is a front view of a conventional tilt angle measuring device (a). FIG. 8 is a side sectional view (b), and FIG. 7 is a graph showing the relationship between the inclination angle θ and the output V of the light receiving unit.
The figure is an explanatory view showing one of the inclined states. 1: Device body, 2: Liquid, 3: Container, 3A, 3B: Glass window, 5,
5 ': rocking member, 6: reflector, 7: reflector, 8, 28: support, 8
A, 28A: tip part, 10: float, 12: guard base, 14: permanent magnet, 16: hole, 20: light source, 22: collimation lens, 24: slit, 30: light receiving part, 30A, 30B: light receiving element, 32, 34: amplification circuit, 36: subtraction circuit, 38: addition circuit, 40: voltage-angle conversion circuit, 42: comparison circuit, 43: current control circuit

Claims (8)

[Claims] 1. A liquid container is provided at the bottom of a container,
A magnet having at least two attraction points located on a straight line, and a light reflecting surface, the lower end is attracted to the attraction point of the magnet, and the upper end is subjected to the buoyancy of the liquid to attract the magnet. An oscillating member configured to oscillate in a direction orthogonal to the straight line direction with a point as a fulcrum and always held in a vertical state, and an integral body with the container for causing light to enter the light reflecting surface. A light source attached to the container, and a light receiving unit that is attached integrally with the container for receiving the reflected light from the light reflecting surface and detecting the displacement of the light receiving point, and measuring the tilt angle from the displacement of the light receiving point. A tilt angle measuring device. 2. The tilt angle measuring device according to claim 1, wherein the magnet is a rod-shaped magnet. 3. The tilt angle measuring device according to claim 1, wherein the swing member has a float attached to an upper end portion. 4. The tilt angle measuring device according to claim 1, wherein the lower end of the magnet is composed of two pointed portions. 5. The tilt angle measuring device according to any one of claims 1 to 4, wherein the lower end of the magnet is formed in a play shape. 6. The tilt angle measuring device according to any one of claims 1 to 5, wherein the swinging member is configured so as not to drop from the attraction point of the magnet. 7. The container has another light-reflecting surface on a surface facing the light-reflecting surface of the oscillating member, and is configured such that reflection is performed twice or more between the two light-reflecting surfaces. The tilt angle measuring device according to any one of claims 1 to 6, which is characterized in that: 8. The light receiving section comprises a pair of right triangular light receiving elements which are arranged on the light receiving plane at a predetermined distance so as to be rectangular as a whole. 8. The tilt angle measuring device according to any one of 7 to 7.