JP2588742Y2 - Tilt angle measuring 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 tilt angle measuring device for measuring a tilt of a device to be measured such as a surveying instrument with respect to a vertical direction.

[0002]

2. Description of the Related Art When a surveying instrument is installed, an inclination with respect to a vertical axis leads to an error in a survey value. In order to obtain accurate survey values, it is necessary to correct the inclination of the vertical axis of a surveying instrument or the like that occurs during installation or during operation of the machine. A tilt angle measuring device for measuring the tilt of a vertical axis installed on an instrument to be measured is disclosed in, for example, Japanese Patent Application Laid-Open No. 60-232502.

This tilt angle measuring device comprises a container for holding a liquid having a horizontal free liquid surface, a light projecting device for emitting an irradiation light beam to the free liquid surface, and a light receiving and receiving light beam reflected from the free liquid surface. A light receiving device capable of detecting a position. In this tilt angle measuring device, the irradiation light beam emitted from the light projecting device irradiates the liquid surface, and the liquid surface is in accordance with the incident angle of the irradiation light beam,
That is, the reflected light beam is emitted at an emission angle corresponding to the inclination of the vertical axis of the device to be measured. The light receiving device receives the reflected light beam and detects the light receiving position, and the deviation between the detected light receiving position and the light receiving position of the reflected light beam detected when the vertical axis of the device to be measured coincides with the vertical direction. Measure the tilt angle from.

As a problem of the inclination angle measuring device utilizing reflection at a free liquid surface, when a sudden temperature change occurs outside, the accuracy may be deteriorated for a long time or measurement may be impossible. . This is because external heat is transmitted directly or indirectly from the device under test to the container, and convection occurs in the liquid due to temperature changes in the container, that is, the free liquid surface cannot maintain a flat surface and the reflected light beam cannot be collected. It is considered that the liquid surface is not stable and the position of the reflected light beam on the light receiving surface is not stable even if the light can be collected.

[0005] Convection of liquids occurs especially when the temperature change in each part of the container is not uniform. In particular, it is considered that convection of the liquid occurs when the temperature of the lower part of the container is locally increased or decreased. For example, in a tilt angle measuring device in which a light projecting device and a light receiving device, which are also heat sources, are installed below a container, the temperature at the lower portion of the container rises prior to the temperature at the upper portion of the container, and convection occurs.

In order to solve this problem, Japanese Patent Laid-Open Publication No.
In the inclination angle measuring device of 0─2322502, a thermally conductive member is provided below the free liquid surface of the liquid. This heat conductive member is made of a metal member, that is, a material having higher thermal conductivity than liquid, and is provided at a depth that does not interfere with the free liquid level even when the apparatus is inclined. The external temperature change is transmitted to the liquid through the container, and the thermally conductive member quickly transmits the temperature change of the liquid in contact with the container to the entire liquid to make the temperature of the entire liquid uniform, and the free liquid level is disturbed by convection. Is prevented from occurring, or the disturbance time is shortened.

[0007]

[Problem to be Solved by the Invention]
In the tilt angle measuring device disclosed in 2502, the upper end of the thermally conductive member is ideally as close to the free liquid level as possible in order to transmit the temperature change of the liquid in contact with the container to the liquid. However, the free liquid surface is assumed to be inclined, and the thermally conductive member must not interfere with the free liquid surface even when the free liquid surface is inclined. In other words, it is ideal that the upper end of the thermally conductive member is as far as possible from the free liquid surface as much as possible. It is not clear whether it is permissible to provide a distance.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a tilt angle measuring apparatus in which the measurement accuracy does not decrease due to an external temperature change or an element that generates heat without providing a heat conductive member in the liquid.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the invention according to claim 1 comprises a container for holding a liquid having a free liquid surface, and a free liquid surface for the liquid held in the container. A light projecting device that emits an irradiation light beam from a certain direction outside the container, and a light receiving device that receives a reflected light beam emitted from the free liquid surface to the outside of the container. In a tilt angle measuring device for detecting the position of the reflected light beam on the light receiving surface of the device and measuring the tilt of the device to be measured with respect to the vertical direction based on this position, the container is formed of a member having poor heat conductivity, and at least the irradiation light beam The outer surface of the container except for the portion intersecting with the optical path of the reflected light beam was covered with a thin heat conductive film.

[0010] The invention according to claim 2 provides a container for holding a liquid having a free liquid surface, a prism member formed of a member having poor thermal conductivity and fixed to the container, and a prism member fixed from the outside of the container. A light projecting device for emitting an irradiation light beam to a free liquid surface of the liquid held in the container via the prism member, and a light receiving device for receiving a reflected light beam emitted from the free liquid surface to the outside of the container via the prism member A tilt angle measuring device that is installed at a portion where the device to be measured is installed and that measures the tilt of the device to be measured with respect to the vertical direction based on the position of the reflected light beam on the light receiving surface of the light receiving device; A support member having a portion and an installation portion fixed to the installation portion of the device to be measured is provided, and the container is fixed to the device to be measured by the support member.

Further, in the invention according to claim 3,
3. The device according to claim 1, wherein the light projecting device and the light receiving device have a supporting portion for supporting the light projecting device or the light receiving device and an installation portion fixed to the device to be measured. Is fixed to the device to be measured via the supporting member. In the present invention, the member having poor heat conductivity may be glass, resin, ceramics, or the like. Further, it is preferable to use a metal foil for the heat conductive film.

[0012]

According to the first aspect of the present invention, a local temperature change occurring around the container is quickly transmitted to the entire thermally conductive film covering the outer surface of the container. The temperature change transmitted uniformly throughout the film with good thermal conductivity gradually propagates to the liquid through the container formed of the member with poor thermal conductivity, so the liquid changes temperature uniformly and slowly, causing severe convection. Does not occur.

According to the second aspect of the present invention, the temperature change generated in the installation portion of the device to be measured is transmitted to the prism member through the supporting member and then to the container. Since the prism member is formed of a member having poor heat conductivity, the temperature change of the container is extremely gradual compared to the temperature change of the installation portion, and as a result, the temperature change transmitted to the liquid becomes gradual,
No strong convection occurs.

According to the third aspect of the present invention, the heat generated from the light projecting device or the light receiving device is slowly radiated through the poorly conductive supporting member. That is, the influence of the heat emitted from the light projecting device or the light receiving device and reaching the container from the device to be measured or transmitted through the air to the container is greatly reduced.

[0015]

1 and 2 show an embodiment of the present invention. The tilt angle measuring device of the present embodiment has a glass prism 15 at the bottom.
A glass container 2 holding a silicone oil 1 having a free liquid surface 1a, a light emitting element 3 and a collimator lens 4
Liquid level 1 from the lower left of the container 2
a light projecting device 13 which emits an irradiation light beam to a, a light receiving device 14 having a light receiving element 5, a condenser lens 6, and a support member 11 and receiving a light beam reflected from the free liquid surface 1a at the lower right of the container 2; Having. In FIG. 1, a part of the glass container 2 is shown by a broken surface.

The glass container 2 has an outer surface covered with a metal foil 7 of aluminum or the like except for a portion intersecting the optical path of the irradiation light beam and the reflected light beam, and a supporting member 9 for supporting the glass prism 15.
And is fixed to the substrate 8 via. The metal foil 7 is a glass container 2
In close contact. Further, a supporting member 10 and a supporting member 1 for supporting and fixing the light projecting device 13 and the light receiving device 14 to the substrate 8 respectively.
Numeral 1 is formed of a member having poor heat conductivity such as ceramics and glass. The substrate 8 is fixed to the inner wall surface of the main body 16 of the device to be measured. The substrate 8 is not always necessary, and the glass container 2, the light projecting device 13, and the light receiving device 14 supported by the support members 9, 10, and 11 respectively are directly connected to the device to be measured without the substrate 8. It may be fixed to the installation portion.

The irradiation light beam emitted from the light emitting element 3 passes through the first lens 4 to become a substantially parallel light beam, passes through the glass prism 15, and irradiates the free liquid surface 1a. The irradiation light beam is reflected by the free liquid surface 1a, and the reflected light beam passes through the glass prism 15 and then condenses on the light receiving surface of the light receiving element 5 through the second lens 6. The light receiving element 5 outputs an electric signal corresponding to the light receiving position of the reflected light beam, and this electric signal is input to a detection circuit (not shown) to detect the inclination angle.

The operation of heat conduction in this embodiment will be described. In FIG. 3, a heat source 12 is for giving a local temperature change to the glass container 2, and in this embodiment, the support member 9 is used.
And the radiant heat from the light projecting device 13 and the light receiving device 14. The space between the metal foil 7 and the glass container 2 in FIG. 3 is provided for convenience of explanation. Heat source 12
The heat indicated by the arrow T1 generated from the glass container 2
Reach intensively below. The local temperature change at the lower portion of the glass container 2 is quickly transmitted to the entire metal foil 7 covering the outer surface of the glass container 2 as indicated by an arrow T2. The temperature change transmitted to the entire metal foil 7 is uniformly transmitted to the entire glass container 2 as indicated by an arrow T3, and is gradually transmitted to the silicon oil 1 through the glass container 2 which is a member having poor heat conductivity. The temperature of each part of the silicon oil 1 changes uniformly and slowly, and no strong convection occurs. That is, there is no ripple that impairs the flatness of the free liquid surface 1a.

Light-emitting element 3 and light-receiving element 5 of tilt angle measuring device
Is also a heat source. Heat generated from the light emitting element 3 of the light projecting device 13 and the light receiving element 5 of the light receiving device 14 is transmitted mainly to the substrate 8 to the glass container 2. In FIG. 2, heat generated from the light projecting device 13 and the light receiving device 14 is indicated by an arrow T.
As shown by reference numeral 4, the light is transmitted through the supporting members 10 and 11 formed of members having poor thermal conductivity, and is transmitted to the substrate 8 gently. The temperature change of the substrate 8 is transmitted through the support member 9 as shown by the arrow T5 and reaches the glass prism 15, and the glass prism 15 gradually transmits the temperature change to the glass container 2. The support members 10 and 11 also function as heat insulating members when the heat generated from the light emitting element 3 and the light receiving element 5 is transmitted to the substrate 8. In addition, the glass prism 15
Serves also as a heat insulating member when a temperature change is transmitted to the silicon oil 1, and blocks a path through which heat is transmitted from the heat source to the silicon oil 1.

[0020]

According to the first aspect of the present invention, since the container is covered with the heat conductive film, the temperature change is quickly transmitted to the entire container, and the temperature change of each part of the container is uniform. Since a container having poor heat conductivity is used for the container, the temperature of the container changes slowly, and the temperature of the liquid changes uniformly and slowly. That is, since strong liquid convection does not occur, the free liquid surface is kept flat, and the inclination angle measurement is not disabled due to a rapid temperature change, so that an inclination angle measuring device with high measurement accuracy can be always obtained.

According to the second aspect of the present invention, the temperature change in the installation portion passes through the prism member at the bottom of the container before being transmitted to the liquid, and is transmitted slowly to the container. It is possible to reduce a factor to exert and obtain a stable free liquid level. That is, it is possible to realize a tilt angle measuring device with high measurement accuracy. According to the third aspect of the present invention, the heat generated from the heat source, that is, the light projecting device or the light receiving device is radiated slowly through the poorly conductive support member. Therefore, the free liquid level is not disturbed by the heat generated from the light projecting device or the light receiving device, and the accuracy of the tilt angle measuring device does not decrease.

[Brief description of the drawings]

FIG. 1 is a front view of a tilt angle measuring device according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA in FIG.

FIG. 3 is a diagram illustrating a state in which heat transmitted to a container of the tilt angle measuring device according to the embodiment of the present invention is transmitted to a liquid.

[Description of Signs of Main Parts]

1. Silicon oil, 1a. Free liquid surface, 2. Glass container, 3. Light emitting element, 4. Collimator lens, 5. Light receiving element, 6. Condensing lens, 7. Metal foil, 8. substrate, 9 support member for container, 10 support member for light emitting device, 11 support member for light receiving device, 13 light emitting device, 14 light receiving device, 15
..Glass prisms

Claims (3)

(57) [Scope of request for utility model registration] 1. A container for holding a liquid having a free liquid surface, a light projecting device for emitting an irradiation light beam from the outside of the container to the liquid surface, and a reflected light beam emitted from the liquid surface to the outside of the container. A light receiving device that receives the light, a tilt angle measuring device that is installed on the device to be measured and that measures the tilt of the device to be measured with respect to the vertical direction based on the position of the reflected light beam on the light receiving surface of the light receiving device. The container is formed of a member having poor heat conductivity, and the outer surface of the container except for at least a portion that intersects the optical path of the irradiation light beam and the reflected light beam is covered with a film having good thermal conductivity. measuring device. 2. A container for holding a liquid having a free liquid surface, a prism member fixed to the container, and a light projecting device for emitting an irradiation light beam to the liquid surface from outside the container via the prism member. And a light receiving device for receiving the reflected light flux emitted from the liquid surface to the outside of the container via the prism member. The light receiving device is provided at a portion where the measuring instrument is to be installed and on the light receiving surface of the light receiving device. In a tilt angle measuring device for measuring a tilt of the device to be measured with respect to a vertical direction based on a position of the reflected light beam, a supporting portion that supports the prism member, while forming the prism member with a thermally poor conductive member A tilt angle measuring device, comprising: a support member having an installation portion fixed to the installation portion, wherein the container is fixed to the device to be measured by the support member. 3. The thermally inferior conductive support member, wherein the light projecting device and the light receiving device have a support portion supporting the light projecting device or the light receiving device and an installation portion fixed to the instrument to be measured. The tilt angle measuring device according to claim 1, wherein the tilt angle measuring device is fixed to the device to be measured via a device.