JPH0660937B2 - Liquid level measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to liquid level height measurement for measuring the height of a test liquid level by using distance measuring light modulated by a predetermined modulation signal. It relates to the device.

(Prior Art) This type of liquid level measuring device measures the height H of a test liquid surface S (hereinafter simply referred to as liquid level S) in the crude oil tank 1 as shown in FIG. 6, for example. It is used to

In FIG. 6, the liquid level measuring device includes a light wave distance measuring unit 2 for generating distance measuring light modulated by a predetermined modulation signal, and an objective optical means 3 for emitting and entering the distance measuring light. An optical fiber 4 for transmitting the distance measuring light from the light wave distance measuring section 2 to the objective optical means 3 is provided. And the objective optical means 3
Is mounted in the upper wall 1a of the crude oil tank 1 via a bracket 5.

In such a liquid level measuring device, when the distance measuring light of a predetermined wavelength is generated in the light wave distance measuring section 2, this distance measuring light is transmitted to the objective optical means 3 through the optical fiber 4 and thereafter. It is irradiated toward the liquid surface S. The irradiated distance measuring light is reflected by the liquid surface S to become reflected light, and the reflected light is returned to the light wave distance measuring unit 2 via the objective optical means 3 and the optical fiber 4. The light wave distance measuring unit 2 calculates the time delay of the reflected light with respect to the modulation signal of the distance measuring light and displays the height H of the liquid surface S.

(Problems to be Solved by the Invention) By the way, the above-mentioned objective optical means 3 of the crude oil tank 1 is so arranged that the optical axis of these objective lenses (not shown) is perpendicular to the liquid surface S. It is attached to the upper wall 1a. This mounting is performed in a state where the crude oil 6 is not contained in the crude oil tank 1. The crude oil tank 1 as described above is deformed when the crude oil 6 is stored therein, and the deformation amount changes depending on the storage amount of the crude oil 6. The amount of deformation also depends on the size of the crude oil tank 1. Moreover, when the crude oil lamp 1 is small, the deformation amount of the crude oil tank 1 due to the storage of the crude oil 6 is small, so that the objective optical means 3 does not tilt due to this deformation.

However, when the crude oil tank 1 becomes larger, the side wall 1b of the crude oil tank 1 is largely curved and deformed laterally by the crude oil 6 stored therein, as shown in FIG. 7, and the upper wall 1a is flattened. Can be greatly deformed. Moreover, in this case, the objective optical means 3 is largely inclined as shown in FIG. As a result, even when the distance measuring light is irradiated from the objective optical means 3 toward the liquid surface S, the reflected light from the liquid surface S does not go to the objective optical means 3 side, and therefore this reflected light is reflected by the objective optical means 3. It was impossible to measure the height H of the liquid surface S by receiving light with an objective lens (not shown).

When the objective optical means 3 and the optical fiber 4 which is the optical transmission means are connected and supported in the crude oil tank 1, the center of gravity of the objective optical means 3 may be the optical fiber depending on the arrangement state of the optical fiber 4 and external vibration. It is conceivable that the weight of 4 itself may cause a shift. When this displacement of the center of gravity occurs, the objective optical means 3 does not directly face the liquid surface,
That is, the directivity direction of the objective optical unit 3 is not perpendicular to the liquid surface S (normal), and the height H of the liquid surface S may not be measured.

Therefore, according to the present invention, even if the support portion of the objective optical means is deformed or displaced under various conditions, the objective light means is always
It is an object of the present invention to provide a liquid level height measuring device that directly faces a test liquid surface.

(Means for Solving the Problems) In order to achieve this object, the present invention is provided with an optical wave distance measuring section for generating distance measuring light modulated by a predetermined modulation signal, and the distance measuring light is emitted and incident. The objective optical means for use is opposed to the surface of the liquid to be tested and supported by the supporting portion above this, and the distance measuring light generated by the light wave distance measuring section is transmitted to the objective optical means via the light transmitting means. By doing so, the distance measuring light is irradiated from the objective optical means to the surface of the liquid to be tested and reflected, and the reflected light is guided to the light wave distance measuring section through the objective optical means and the light transmitting means. In the liquid level height measuring device in which the time delay between the modulated signal and the reflected light is calculated in the light wave distance measuring section and the height of the test liquid level is known from this, the objective optical means is a gimbal mechanism. Is supported by the supporting part via a part of the optical transmission means. The liquid level height measuring device is provided coaxially with the rotation axis of the valve mechanism.

(Operation) According to such a configuration, even if the support portion above the test liquid surface is deformed or displaced due to various conditions, the objective optical means supported by the support portion always moves in the vertical direction via the gimbal mechanism. Will turn to.

(Example) Hereinafter, the present invention will be described with reference to FIGS. 1 to 5.

1 to 3 show a first embodiment of the present invention. In FIG. 3, 7 is a base for a crude oil tank, and 8 is
Is a crude oil tank installed on the base 7, 8a is an upper wall (support portion) of the crude oil tank 8, 8b is a side wall of the crude oil tank 8, and 9 is a management tower adjacent to the crude oil tank 8. Further, 10 is the crude oil stored in the crude oil tank 8, S is the test liquid level of the crude oil 10 (hereinafter simply referred to as liquid level), and H is the height of the liquid level S.

The liquid level measuring device for measuring the height H of the liquid level S of the crude oil 10 stored in the crude oil tank 8 includes a light wave distance measuring unit 11 for generating distance measuring light modulated by a predetermined modulation signal. An objective optical means 12 for emitting and entering the distance measuring light and an optical transmission means 13 for optically connecting the light wave distance measuring section 11 and the objective optical means 12 are provided.

As shown in FIG. 2, the light wave distance measuring unit 11 outputs a modulated signal to the light emitting diode 14 that emits the distance measuring light, the light receiving diode 15 that receives the reflected light, and the light receiving diode 15 from the light receiving diode 15. The arithmetic processing control circuit 16 to which the output signal of 1 is input, and the display 17 to which the output from the arithmetic processing control circuit 16 is input. This arithmetic processing circuit 16 inputs a predetermined modulation signal to the light emitting diode 14, and at the same time delays the output signal from the light receiving diode 15 and the above-mentioned modulation signal with respect to the modulation signal of the reflected light (phase difference).
Is calculated. Then, this calculated time delay is displayed on the display.
It is input to 17, and the display 17 displays the height H of the liquid surface S. The distance measuring light emitted from the light emitting diode 14 is a prism.
Guided to the joint optical system 20 via 18 and lens 19,
The reflected light from the joint optical system 20 is input to the light receiving diode 15 via the lens 19 and the prism 18.

The joint optical system 20 includes a lens 21 facing the lens 19 and a prism 22. The optical transmission means 13 is composed of this joint optical system 20 and a pair of optical fibers 23, 24, and one ends 23a, 24a of the optical fibers 23, 24 are made to face the reflecting surfaces 22a, 22b of the prism 22, respectively. ing.

The objective optical means 12 has a lens barrel as shown in FIGS.
25, a prism 26 arranged in the upper portion of the lens barrel 25,
It is composed of an objective lens 27 mounted in the opening of the lower end of the lens barrel 25. At the upper part of the lens barrel 25, supporting cylinder portions 25a, 25b projecting from the outer peripheral surface shifted by 180 ° are provided, and each of the supporting cylinder portions 25a, 25b is a reflecting surface 26a, 2 of the prism 26.
It corresponds to 6b and is located coaxially. Such an objective optical means 12 is disposed in the crude oil tank 8 and is mounted on the bracket 28 on the upper wall 8a side of the crude oil tank 8 via the gimbal mechanism 29.

The gimbal mechanism 29 includes an inner ring 30 loosely fitted to the outer periphery of the upper portion of the lens barrel 25, and an outer ring 31 loosely fitted to the outer periphery of the inner ring 30. Then, the inner ring 30 has support cylindrical portions 30a, 30b protruding inward at a position displaced by 180 °.
And the support cylinder that protrudes outward at a position that is 90 ° away from this
30c and 30d are integrally provided. In addition, the outer ring 31 has a support tube portion 31 protruding inward at a position displaced by 180 °.
a and 31b are integrally provided. Moreover, the support cylinders 30a, 3
0b is rotatably supported in the supporting tube portions 25a, 25b of the lens barrel 25 via bearings 32, 33, and the supporting tube portions 30c, 30d are bearings 34, 35 in the supporting tube portions 30a, 31b of the outer ring 31. It is rotatably supported via. In addition, the support cylinder portions 30a, 30b
The support cylinders 30c and 30d are provided coaxially with each other, and the support cylinders 31a and 31b are provided coaxially with each other.

Then, the other end 23b side of the optical fiber 23 described above is inserted through the support tubular portion 31a of the outer ring 31 and the support tubular portion 30c of the inner ring 30, and along the outer peripheral surface of the inner ring 30, the inner Support tube for ring 30
It is inserted through 30a. As a result, the portion 23c of the optical fiber 23 that faces inward of the inner ring 30 is coaxial with the support cylinder portion 30a that serves as a rotation axis, and the portion 23d of the optical fiber 23 that faces toward the inside of the outer ring 31 serves as a support cylinder portion 30c that serves as a rotation shaft. It becomes coaxial with. Moreover, the end surface of the other end 23b of the optical fiber 23 corresponds to the reflecting surface 26a of the prism 26.

Further, the other end 24b side of the optical fiber 24 has a support tube portion 31b of the outer ring 31 and a support tube portion 30d of the inner ring 30.
Is inserted along the outer peripheral surface of the inner ring 30, and is also inserted into the support tubular portion 30b of the inner ring 30. As a result, the portion 24c of the optical fiber 24 facing inward of the inner ring 30 is coaxial with the support cylinder portion 30b serving as the rotation axis, and the portion 24d of the optical fiber 24 facing inward of the outer ring 31 is defined as the support cylinder portion 30d serving as the rotation axis. It becomes coaxial.

Next, the operation of the liquid level height measuring device having such a configuration will be described.

When the light emitting diode 14 is caused to emit light by the modulation signal from the arithmetic processing restriction circuit 16, the light emitting diode 14 emits distance measuring light. This distance measuring light is generated by the prism 18, the lenses 19 and 21,
Objective optical means 12 through prism 22 and optical fiber 23
After being guided inside, it is emitted from the other end 23b of the optical fiber 23 toward the reflecting surface 26a of the prism 26. The emitted distance measuring light is irradiated toward the liquid surface S in the crude oil tank 8 through the reflecting surface 26a and the objective lens 27, and is reflected by the liquid surface S.

The reflected light reflected by the liquid surface S is incident on the light receiving diode 15 via the objective lens 27, the reflecting surface 26b of the prism 26, the optical fiber 24, the prism 22, the lenses 21, 19 and the prism 18. As a result, a signal is output from the light receiving diode 15, and this output signal is input to the arithmetic processing control circuit 16. Then, the arithmetic processing control circuit 16 calculates a time delay with respect to the modulation signal of the reflected light from the modulation signal and the output signal from the light receiving diode 15, converts this to the liquid level height, and inputs it to the display unit 17. . As a result, the height H of the liquid surface S
Is displayed on the display unit 17.

By the way, when the crude oil tank 8 equipped with the objective optical means 12 is deformed due to the weight of the crude oil 10 or other causes and the upper wall 8a of the crude oil tank 8 is deformed or displaced, the objective optical means 12 The inner ring 30 of the gimbal mechanism 29 rotates about the support cylinders 30c and 30d via the bearings 34 and 35, and the lens barrel 25 supports the support cylinder 30a of the inner ring 30 via the bearings 32 and 33. Rotate around 30b. These rotations are performed relatively. As a result, the objective lens 27 of the objective optical means 12 always faces the liquid surface S directly. That is, the optical axis of the objective lens 27 is always orthogonal to the liquid surface S. As a result, the light emitted from the objective lens 27 is reliably received by the objective lens 27 after being reflected by the liquid surface S.

In the embodiment described above, the supporting cylinder portions 30a, 30b, 30c, 30d are supported by the bearings 32, 33, 34, 35 in the supporting cylinder portions 25a, 25b, 31a, 31b, and the other end portion 23b of the optical fiber 23. Insert the side over the support cylinders 30a, 25a and 30c, 31a,
Although the other end 24b side of 24 is inserted so as to straddle the support cylinder portions 30b, 25b and 30d, 31d, it is not necessarily limited to this configuration, and is shown in, for example, FIG. 5 and FIG. You may form like.

In this embodiment, the support tube portions 25a and 25b of the lens barrel 25 and the support tube portions 30c and 30d of the inner ring 30 are formed in a tapered shape. Further, tapered hole portions 30e and 30f are formed at the tip end portions of the support cylinder portions 30a and 30b of the inner ring 30, and the outer ring 3
Tapered hole portions 31c and 31d are formed at the front end portions of the first support cylinder portions 31a and 31b. Then, the tip ends of the support tubular portions 25a, 25b, 30c, 30d are rotatably abutted in the tapered hole portions 30e, 30f, 31c, 31d.

Moreover, on the outer peripheral surface of the outer ring 31, the support tubular portion 31a,
Connection tube parts 31e and 31f coaxial with 31b are provided.
Cylindrical connectors 36 and 37 are screwed onto the outer circumferences of 31e and 31f, and the other ends of the optical fibers 23 and 24 are attached to the cylindrical connectors 36 and 37.
23b and 24b are inserted. Then, both ends of the optical fiber 38 along the outer circumference of the inner ring 30 are fitted to the supporting cylinder portions 30a and 30c, and both ends of the optical fiber 39 along the outer circumference of the inner ring 30 are fitted to the supporting cylinder portions 30b and 30d. The part is fitted.

Further, collimator lenses 40 and 41 are attached to the support tubular portions 25a and 30a, collimator lenses 42 and 43 are attached to the support tubular portions 25b and 30b, and a collimator lens 44 is attached to the support tubular portion 30c and the tubular connector 36. , 45 are mounted, and collimator lenses 46, 47 are mounted on the support cylindrical portion 30d and the cylindrical connector 37.

The joint optical system 20, the optical fiber 23, the collimator lenses 45 and 44, the photo diode 38, the collimator lens 41,
The distance measuring light guiding optical path is formed from 40 etc., and the reflected light guiding optical path is formed from the collimator lenses 42, 43, the optical fiber 39, the collimator lenses 46, 47, the optical fiber 24 and the joint optical system 20. The distance measuring light guiding optical path and the reflected light guiding optical path constitute an optical transmission means. Also in this embodiment, a part of the optical axis of the distance measuring light guiding optical path serves as a supporting cylinder portion 25a, 30c which is coaxial, and a part of the optical axis of the reflected light guiding optical path serves as a rotating shaft supporting cylinder portion 25b, It is coaxial with 30d.

In such a configuration, the distance measuring light is guided to the objective optical means through the distance measuring light guiding optical path, and the guided distance measuring light is guided through the reflecting surface 26a of the prism 26 and the objective lens 27. The surface S is illuminated. Then, the reflected light reflected from the liquid surface S by this irradiation is returned to the light wave distance measuring unit via the objective lens 27, the reflecting surface 26b of the prism 236, and the above-described reflected light guide path. The gimbal mechanism 29 also operates in the same manner as the embodiment shown in FIGS. 1 and 2.

In this embodiment, since the optical fibers 23 and 24 do not straddle the joint between the inner ring 30 and the outer ring 31 of the gimbal mechanism 29, the gimbal mechanism 29 can be operated smoothly, and the objective optical means 12 can be used as a liquid. The surface S can be surely faced.

(Effects of the Invention) As described above, the present invention is provided with an optical wave distance measuring section for generating distance measuring light modulated by a predetermined modulation signal, and is provided with objective optical means for emitting and entering distance measuring light. The distance measurement light generated by the light wave distance measuring section is transmitted to the objective optical means via the light transmitting means while being opposed to the surface of the test liquid and supported by the supporting portion above the liquid level measuring section. Distance light is radiated from the objective optical means to the surface of the test liquid to be reflected, and the reflected light is guided to the light wave distance measuring section through the objective optical means and the light transmitting means, and within the light wave distance measuring section. In the liquid level height measuring device in which the time delay between the modulated signal and the reflected light is calculated and the liquid level height to be detected is known from this, the objective optical means includes the supporting portion via a gimbal mechanism. And a part of the optical transmission means is the same as the rotating shaft of the gimbal mechanism. Since the liquid level height measuring device is provided on the shaft, even if the supporting portion of the objective optical means is deformed or displaced under various conditions, the optical axis of the objective optical means is acted by the action of the gimbal mechanism. Always automatically in the vertical direction,
The objective optical means can always face the test liquid surface.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a liquid level height measuring device showing a first embodiment of the present invention, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, FIG. 3 is FIG. FIG. 4 is an explanatory view showing an example of use of the liquid level height measuring device shown in FIG. 2, FIG. 4 is a sectional view of a main part of a liquid level height measuring device showing another embodiment of the present invention, and FIG. FIG. 4 is a plan view in which a part of FIG. 4 is broken away, and FIGS. 6 and 7 are explanatory views showing an example of use of a conventional liquid level height measuring device. 11 ... Light wave distance measuring section, 12 ... Objective optical means, 13 ... Optical transmission means, 27 ... Objective lens, 29 ... Gimbal mechanism, 30 Inner ring, 31 ... Outer ring.

Claims (1)

[Claims] 1. An optical wave distance measuring section for generating distance measuring light modulated by a predetermined modulation signal is provided, and an objective optical means for emitting and entering the distance measuring light is made to face the surface of the test liquid. The distance measuring light generated by the light wave distance measuring section is transmitted to the objective optical means via the light transmitting means, so that the distance measuring light is transmitted from the objective optical means to the test liquid. The surface is irradiated and reflected, and the reflected light is guided to the light wave distance measuring section through the objective optical means and the light transmitting means, and a time delay between the modulated signal and the reflected light is generated in the light wave distance measuring section. In the liquid level measuring device, which is calculated to obtain the liquid level of the test liquid from this, in the liquid level measuring device, the objective optical means is supported by the supporting part via a gimbal mechanism, and A portion is provided coaxially with the rotation axis of the gimbal mechanism. Liquid level measuring device.