JP2578913Y2 - Reflector support device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflector supporting device for supporting a reflecting mirror for reflecting a laser beam at a predetermined height on the ground, and more particularly to a reflecting mirror supporting device which is not affected by weather changes. The present invention relates to a reflecting mirror supporting device that can be guided in a direction.

[0002]

2. Description of the Related Art In some plants, storage facilities, pipes and the like for storing and transferring flammable and toxic gases are arranged over a wide range. If flammable or toxic gas leaks from such plant equipment, it is dangerous. Therefore, it has been considered to provide an optical gas detection device for detecting gas leakage in the plant.

[0003] An optical gas detection device detects gas leakage by using spectral absorption by gas.
The principle is well known, and light with a wavelength corresponding to the absorption spectrum inherent to the component material is absorbed, and the degree of absorption at that time is related to the concentration of the component. Can be measured to determine the concentration of the component.

In order to monitor a plant using such a gas detection device, a wide range is to be measured. Therefore, it is necessary to use a laser beam as a light source and install a reflecting mirror at a key point to guide the laser beam. Thereby, an optical path for measurement is formed in the atmosphere around the plant. In order to detect gas leaks early, the measuring optical path must be spread over a wide area of the plant so as not to be overlooked. To this end, the measurement optical path is provided along a complicatedly routed plant pipe, passing near a large tank or the like and bypassing an obstacle. In a place where a person or a car passes, a measurement optical path is provided at a position higher than the ground surface so that light is not blocked.

In order to form such an optical path for measurement at a position higher than the surface of the ground, a reflecting mirror supporting device 61 shown in FIG. 6 has an elongated supporting column 2 planted on the ground G and a reflecting mirror 3 mounted on the supporting column. It is installed on the top of The height of the reflecting mirror from the ground surface is set to about 2 m in consideration of the traffic of people.

[0006]

[Problem to be Solved by the Invention] By the way, the supporting column 2
Is composed of an iron pipe or the like, and the iron pipe expands due to thermal expansion due to a temperature rise during the day. Further, the temperature of the iron pipe rises even when it is exposed to direct sunlight, but since the temperature rise is uneven between the sunshine side and the shade side, warpage or twisting due to thermal expansion occurs.

[0007] Such deformation of the support column 2 such as elongation, warpage, and torsion appears largely at the top of the support column 2 because the support column is formed elongated. Therefore, the reflecting mirror 3
Will cause an angle or misalignment.

[0008] The displacement of the reflecting mirror 3 is a serious obstacle for the gas detector of the plant. This is because the measuring optical path traverses a wide range of the plant, so that the optical path length is very long and the distance between the reflecting mirrors is very large. Therefore, even if a slight angle shift occurs in the reflecting mirror 3, the light largely deviates before reaching the next reflecting mirror. Then, while the light is reflected by many reflecting mirrors, the light is completely separated from the optical path for measurement. For this reason, measurement becomes impossible.

As described above, since the supporting column 2 is formed to be long and thin in order to set the reflecting mirror 3 at a high position, the change in the temperature and the deformation due to the sun may cause a large angle and displacement of the reflecting mirror. This is a problem in maintaining the measurement optical path correctly.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide a reflector supporting device which can guide a laser beam to a target direction without being affected by a change in weather.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method for measuring on a ground surface or a fixed object on the ground surface.
Support device that supports a reflecting mirror that reflects the laser light
There are, apart the support pillars for fixing the reflector to a predetermined position, a reflecting mirror mounted on its post, a heat insulating material covering the support posts, the distance the reflecting mirror and the support posts
It consists of a shading member which surrounds, the sunshade member upper
Surrounds the reflecting mirror and the supporting column and is transparent on the laser optical axis.
A side plate having an overwindow and a top opening formed by the side plate
The top plate covers the mouth .

[0012]

In order to develop a gas detection device for the above-mentioned plant, the present applicant has been studying on prevention of displacement of the reflector.
They found that there was a great difference in the degree of the difference between daytime and nighttime. Then, the magnitude of the deviation of the reflector and the temperature during the day were measured, and it was found that the deviation of the reflector was related to the change in temperature, and that the deviation was relatively small at night. Furthermore, we thought that the displacement of the reflecting mirror might be related to the temperature of the support pillar, and measured the daily temperature change at multiple points on the support pillar, and found that the temperature rise was biased between the sunlit side and the shaded side. I also discovered something.

Based on these findings, the displacement can be eliminated if the temperature of the support column is not affected by changes in air temperature and direct sunlight does not hit the support column. That is, with the above configuration, the support pillar covered with the heat insulating material can maintain a constant temperature even when the air temperature changes.
Further, since the sunshade member surrounds the support pillar, temperature unevenness due to direct sunlight is prevented. Thus, the supporting column is free from deformation, and the reflecting mirror can always direct the laser beam in the desired direction without being affected by changes in weather.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

As shown in FIG. 1, a reflector supporting device 1 according to the present invention includes a support column 2 provided upright on the ground surface or a fixed object on the ground surface, and a reflector mounted on the top of the support column. 3, a heat insulating material 4 covering the support columns 2, and a sunshade member 5 surrounding these.

The support column 2 is formed by implanting a cylindrical iron pipe having a predetermined diameter on the ground G, and the height h of the ground portion is 1.9 m. A fixing base 6 is horizontally mounted on the top of the support column 2, and a reflecting mirror 3 for reflecting a laser beam is mounted on the fixing base 6 with a reflecting surface vertical. In this embodiment, the incident angle and the reflection angle of the laser beam form a right angle,
The laser light is incident from the direction of arrow A in the figure and is reflected in the front direction of the drawing.

The heat insulating material 4 is formed by winding a glass wool tape or sheet having a thickness of 75 mm along the outer periphery of the support column 2. The above-ground portion of the support pillar 2 is uniformly covered with a heat insulating material 4.

The sunshade member 5 surrounds side plates 7 extending from the surface of the ground to the upper side of the reflecting mirror 3 along the support columns 2 and arranged on four sides of the support columns 2, and covers the top opening with a top plate 8. It is a thing. The side plate 7 is provided so as to be orthogonal to the incoming and outgoing direction of the laser light, and a transmission window 9 having a predetermined size is provided at a position where the laser light is incident and at a position where the laser light is emitted. In the figure, the transmission window 9 of the side plate on the near side of the drawing is indicated by a broken line. Wood is used for the sunshade member 5 of this embodiment in order to avoid a temperature rise due to direct sunlight.

Next, the operation of the embodiment will be described.

In the reflector supporting device 1, since the sunshade member 5 is provided with the transmission window 9 for the incident light and the outgoing light, the use of the reflecting mirror 3 is not hindered.

The support column 2 covered with a heat insulating material 4 such as glass wool is shielded from exchange of temperature with the outside air, and can maintain a constant temperature even when the temperature changes. Therefore, deformation of the support column 2 due to thermal expansion is prevented.

The sunshade member 5 prevents direct sunlight from hitting the support column 2, the reflecting mirror 3, and the heat insulating material 4. Since the awning member 5 surrounds the support pillar 2 on all sides and on the upper side,
Even if the direction of the sun changes, direct sunlight is blocked all day. Since the direct sunlight is blocked in this way, local temperature rise of the support column 2 due to the direct sunlight is eliminated, and deformation such as warpage or twisting is eliminated.

The function of the heat insulating material 4 and the sunshade member 5 prevents the support column 2 from being deformed all day. Since the supporting column 2 is not deformed, the reflecting mirror 3 can always guide the laser beam to a target direction without being affected by a change in weather.

Next, the magnitude of the deviation of the reflector between the case where the reflector support device 1 is used and the case where the conventional reflector support device having only a support column is used is compared with experiments to find out the present invention. To clarify the effect.

An experimental apparatus shown in a plan view in FIG. 2 was used for the comparative experiment. That is, two reflector supporting devices 1 are arranged outdoors relatively close to the light source 21, and the laser beam 22 is guided indoors by the reflector supporting device on the downstream side. Indoors, laser light 2
The screen 23 was provided orthogonally at an interval of about 50 m on the extension of the second. The screen 23 has a vertical direction (y direction)
A scale or the like is provided in the horizontal direction (x direction) so that the position of the projected laser beam spot can be measured. The north direction is shown in the figure.

In the measurement, the temperature was measured every fixed time, the xy position of the spot, and the temperature in each direction around the support column, and the result was recorded on the time axis.

In the above experimental apparatus, the case where both the two mirror supporting devices are the mirror supporting device 1 of the present invention and the case where both are the conventional mirror supporting device 61 are as follows.
A similar experiment was performed. However, the temperature in each direction around the support column in the case of the present invention was not measured. In addition, there are differences in temperature due to different experiment days.

The results of the comparative experiment are shown in FIGS.

First, looking at the measurement results in the conventional case shown in FIG. 4, on the x-axis in FIG. 4A, the spot rapidly moves to the minus side at 7:00 in the morning, and reaches a peak around 16:00 in the evening. ing. There is a maximum change of 20 mm. On the y-axis in FIG. 4B, the spot once moves to the minus side at 7:00 in the morning, immediately afterwards, swings sharply to the plus side, and then moves violently to the minus side from morning to afternoon. Peaks at A change of 50 mm or more is observed at the maximum.

On the other hand, looking at the measurement results in the case of the present invention shown in FIG. 3, there is a spot at almost the same position on the x-axis in FIG. 3 (a), and there is some fluctuation on the y-axis in FIG. 3 (b). It keeps a nearly constant position of things.

When comparing FIG. 3 and FIG. 4, in the conventional case, the position of the spot is 20 m on the xy axis during one day.
m and 50 mm, whereas in the case of the present invention, it is within a range of 5 mm at the maximum. FIG.
4 (c) and FIG. 4 (c), there is a difference of about 10 degrees, but the temperature change is almost the same. Accordingly, it can be seen that the blurring of the reflector supporting device of the present invention is less than that of the conventional device under the same temperature change.

FIG. 5 shows the temperature in the conventional case around the support pillar (southwest, south, southeast, northeast, north, northwest). Although the temperature is constant, the temperature difference starts to widen, and at around 16:00, the temperature on the southwest side and the south side is particularly high, and there is a temperature unevenness near 15 degrees. When this is matched with the measurement result of the conventional case in FIG. 4, the peak of the temperature unevenness coincides with the peak of the change of the x-axis and the y-axis, and the uneven temperature of the support column is a cause of the fluctuation. You can see that. In the case of the present invention, the temperature around the support column could not be measured. However, from the measurement result of the blur shown in FIG. 3, it can be inferred that the temperature unevenness of the support column has been eliminated.

As described above, in the reflector supporting device of the present invention, the supporting column is not deformed by the influence of the temperature or direct sunlight, and the reflector always maintains the correct laser beam axis.

In this embodiment, the support columns 2 are provided upright on the ground G.
Of course, it may be provided so as to project obliquely.

[0035]

According to the present invention, since the laser beam axis passing outdoors is stabilized without being affected by changes in weather, the reliability of an outdoor gas detection device such as a plant is improved.

[Brief description of the drawings]

FIG. 1 is a structural view showing an embodiment of the present invention.

FIG. 2 is a sketch of an experimental device for examining the effect of the present invention.

FIG. 3 is a diagram illustrating a graph in which a light shift according to an experimental result of the present invention is recorded.

FIG. 4 is a diagram showing a graph in which a light shift based on an experimental result of a conventional example is recorded.

FIG. 5 is a diagram showing a graph in which temperature unevenness of a support column due to direct sunlight is recorded.

FIG. 6 is a structural view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reflector support apparatus 2 Support pillar 3 Reflector 4 Insulation material 5 Sun shade member 6 Transmission window

──────────────────────────────────────────────────続 き Continuing on the front page (72) Takao Kurata Innovator, Tonichi Technical Center, 3-1-1-15 Toyosu, Koto-ku, Tokyo (72) Inventor Yoshio Kusaba 3-chome, Toyosu, Koto-ku, Tokyo No. 1-15 Ishikawa Shima Harima Heavy Industries, Ltd. Toji Technical Center (56) References JP-A-49-84191 (JP, A) JP-A-3-63612 (JP, A) (58) Fields studied (Int) .Cl. ⁶ , DB name) G02B 7/18 G02B 7/00

Claims (1)

(57) [Scope of request for utility model registration] On the 1. A ground or on ground of fixture, the support device for supporting a reflecting mirror for reflecting the laser beam for measurement, a support pillar for fixing the reflector to a predetermined position, the A reflecting mirror mounted on the support, a heat insulating material covering the support column, and the reflector and the support column spaced apart from each other
A surrounding awning member , wherein the awning member is
Surrounds the mirror and support column and transmits on the laser optical axis
A side plate having a window and a top opening formed by being surrounded by the side plate
And a top plate for covering the mirror.