SU1420369A1 - Device for measuring angles of inclination - Google Patents

Abstract

The invention can be used on marine objects in conditions of rolling and allows to increase the accuracy of measurements. On a freely suspended 6, symmetrically with respect to its axis, the same evacuated U-shaped tubes 12,13 filled with mercury are fixed at an angle. When the device is operating under conditions of rolling, the symbol 6 measures the angles of inclination of the object, produced on the measuring scales 10, 4 and 15. With the help of tubes 12, 13, the angle at which the rod of the antenna deviates from the plumb line when the object is tilted . 2 Il.

Description

AND

12

Gz

/;

(L

with:

one

/five

FIG. 7

The invention relates to instrumentation, in particular, devices for measuring tilting angles of a pendulum type, and can be used on marine objects (ships, vessels, hydrometeorological floating stations and other vessels) in rolling conditions.

The aim of the invention is to improve the measurement accuracy.

Fig. 1 schematically shows a device for measuring tilt angles; FIG. 2 is a scheme of sIL acting on a pilot when rolling.

The device for measuring tilt angles contains coaxial vessels 1 connected by a tube 2 with an adjustable throttle needle valve 3. The upper parts of vessels 1 are sealed and connected by air ducts 4 to a liquid differential pressure gauge 5 of the i-type 5, which is mounted on a mechanical master 6, freely suspended from the axis 7 and provided with a weight 8 in its lower part. The differential meter 5 has a measuring scale 9, which is intended to measure the static inclination of the object, i.e. for measuring static roll or trim, depending on which plane the device is mounted in. The pilot 6 has a measuring scale 10 for measuring the dynamic inclination of the object. The connecting air ducts 4. made with flexible inserts 11, providing freedom of swing of the mechanical master 6 within the angles of the Tilt of the object. On the tilt 6, left and right, at the inclined angle o6 / 2 and symmetrically with respect to the tilt axis, in the plane of its swing, the same evacuation and mercury-filled tubes 12 and 13 of the i-shaped type are fixed, in which one end is plugged and the other is open for communication with atmospheric pressure. The tubes 12 and 13 are installed in planes perpendicular to the plane of the swing of the tiller 6 (i.e., perpendicular to the plane of the drawing (FIG. 1), where the knee is conventionally shown by broken lines and the ends of the tubes are spaced apart). Tubes 12 and 13 have measuring scales 14 and 15, respectively, which are designed to measure the levels of mercury in tubes 12

and 13 in order to determine the angle of deviation of the tiger 6 from the plumb line. Angle measuring device

the slope of the offshore facility works as follows.

When the object stands on an even keel, the fluid in the vessels 1 is located at the same level in the horizontal plane, the throttle valve 3 is open and the pressure in the upper cavities of the vessels 1 and the air ducts 4 are the same. Therefore, the differential pressure gauge 5 is in the zero position and does not produce counts on the measuring scale 9. Do not make readings on the measuring scale 10, since the axis of the parallel 6 in this case coincides with the plumb line. Not produced

0 is also counted on scales 14 and 15, since with the plumbing position of the tandem 6, the levels of mercury in tubes 12 and 13 are the same.

With a static inclination of the object, the device changes its position. At the same time, the liquid in the vessels begins to flow from the upper vessel to the lower one. Its movement is like a hydraulic mantle. Under the action of the developed pressure difference in the air cavities of the vessels 1 and air ducts 4, the differential pressure meter 5 changes the readings in proportion to the angle of inclination. which is counted on the scale 9.

5 Simultaneously mechanical tutorial 6 also off 1 | From the zero position of the cabinet 10 at the same angle, the value of which can be read off along this cabinet. Since in this case

0, the 6 is left in the vertical position, the levels of mercury in the tubes 12 and 13 are the same and the readings on the scales 14 and 15 are not produced.

When measuring object inclinations

5 during rolling, adjustment of the device with the help of a throttle valve is necessary. For the flow area of the pipeline is changed by a predetermined amount (constant for a given type of object), ensuring minimal flow of the working fluid in the vessels 1, due to the pumping of the object. This makes it possible to measure the averaged values of the static angle.

5 tilt of the object on a scale 9 of the diffuser 5.

When the device operates in the indicated dynamic modes, the mechanical end 6 provides a measurement of the angle 30 20369.

s tilt object characterizing

Mena ok ve et you yes cr

it rolls in this plane under the influence of variable external disturbances. In this case, readings are made on measuring scales 10.14 and 15.

When an object moves a MoipcKcro, the mechanical idling, if it is suspended at a point that does not coincide with the center of swing of the object body, shows the angle of inclination of the object that is not equal to the real one.

In Figure 2, the straight line OA is the trace of the diametral plane of the sea object, which was tilted when side rolling to the angle If to the vertical, point O is the center of swing of the object, point A is the point of suspension of the tangent located at distance from the center of swing

Making a read on a tactile scale (scale 10), in fact, get the angle cp,, not equal to cf. At the same time (figure 2) tf, q + utp; .

In the general case, this is due to the fact that at the crush of the marine object for each mass unit at point A, acceleration of gravity g and acceleration a, due to the action of tangential aj- and radial a., Accelerations at vibrational

movement point A when rolling. Therefore, at each given moment, the rod is directed not along the direction of acceleration of the force of gravity g, but along the resultant R, i.e. deviates from the plumb line by the angle & Cf.

The neglect of the & Cf angle can lead to a significant error in determining the dynamic angles of inclination of the marine object.

So, if the tandem is suspended at a distance of 2 m from the center of swing of the marine object, during rolling with a period of 6s and an amplitude of 25, the error in determining the dynamic angle of inclination reaches 5.

Therefore, in order to determine the angle in the device, the mercury tubes 12 and 13 with the scales 14 and 15 are mounted on the instrument 6 and fixed obliquely at an angle of ° C / 2 symmetrically with respect to the axis of the satellite. At the same time, to compensate for the effect of acceleration on mercury levels in tubes of the U-shaped plane, tubes 12 and 13 are perpendicular to the plane of swing of the rod 6.

If an i-shaped tube with a diameter of 7-10 mm with a plugged (sealed) one end having a length of about 0.9 m is filled with mercury and turned upside down with a plugged end, at this end of the tube the mercury drops to a height corresponding to the atmospheric pressure on mercury in the open end of the tube.

When such a tube is tilted, the end of the mercury column remains at the same height above the free surface of the mercury, and the length of the column becomes longer when tilted. This is due to the fact that the pressure depends only on the height of the liquid column measured by the vertical.

Counts of the length of the barometric column, made at the vertical position of the tube H, and when tilted

its angle, i.e. binds formula

in position H

s

H „cos oi / 2.

five

0

five

The scales 14 and 15, according to which the length of the barometric pillars are counted, are associated with tubes 12 and 13, respectively. Therefore, when the tubes 12 and 13 are tilted, the readings on the scales 14 and 15 are larger than when the tubes are plumb.

For the pillar lengths of mercury H, 2 and H, in tubes 12 and 13

LC arctg

4j

.

(H, 1st H

.1-1%.)

one.

tg

s

0

0

five

Where

ci / 2 I., H

13

the installation angle of the tubes 12 and 13 relative to the axis of the tandem 6;

readings on scales 14 and 15 of the lengths of mercury columns in tubes 12 and 13, respectively.

The tubes 12 and 13 can be installed obliquely relative to the axis of the pendulum 6 at different angles / 3 and. For example, if they are tilted in the same direction, the indicated dependence is

H 11 cos ft - 3, cosif ucf arctg --- ll-JI- - - lJ-Has a measured dynamic angle of inclination cf, and calculated L (based on measured levels H, 2 and HIJ, taking into account angles: Ga S). / 2, real dynamic angle

11kl (maritime object is received as If 4 i utf.

Claims (1)

Invention Formula A device for measuring tilt angles, containing vessels partially filled with liquid, communicating in fluid through a tube with a throttle valve, and in air through a flexible tube - with a differential 203696 An i-shaped manometer fixed on the master, characterized in that, in order to increase the accuracy of the g measurements, it is equipped with two vacuumized and u-tubes with mercury, one open end fixed on the master symmetrically and obliquely about its axis in a flat - 10 bones x perpendicular to the plane of the tambourine. fi $ .2