SU1483383A1 - Instrument for calibration of movement parameter meters - Google Patents

Abstract

The invention relates to the metrology of measurement of motion parameters. The purpose of the invention is to expand the working range of the calibration. The plate 1 with the helical profile of the working surface is mounted on the rotating platform 2. The graduated transducer 4 is connected with the working surface of the plate 1 with the help of the lever 3 (soft coupling). During the rotation of the plate 1 around the axis, a test signal of a given shape, amplitude and frequency is reproduced. Plate 1 can be replicated from the same matrix. The non-rigid connection of the calibrated transducer 4 with the surface of the plate 1 can be carried out by means of a conventional corundum needle. 1 il.

Description

C |

The invention relates to a measurement technique and can be used in metrological assurance of linear and angular accelerometers, tachometers, vibrometers, velocimeters, means of measuring unevenness of rotation, and other means of measuring motion parameters.

The aim of the invention is to expand the working range of the calibration.

The drawing shows schematically a device for the calibration of motion parameter meters.

The device contains means for reproducing motion parameters in the form of a drive (not shown) with a vertical axis of rotation with platform 1 fixed on its shaft, on which a disk (or plate) 2 is located horizontally with the possibility of its working surface interacting with a signal pickup unit in the form of a platform 3 two degrees of freedom, a graduated gauge 4, a sound pickup device 5 (for example, using a corundum needle), a recording device 6 (for example, a plotter). The working surface of the disk is made spiral.

The device works as follows.

First, the methods adopted in the recording technique, produce a matrix with a given profile. The profile forms two spiral grooves. One of them (the main one) is intended for setting a platform with two degrees of motion according to a given law.

The second groove is used to measure the rotation angle of a platform with one degree of freedom. It is made in the usual way (for example, in the form of an Archimedes spiral) and carries the record in the form of electrical impulses with a constant period of follow or codes of the angular position.

Using a single matrix with a given profile of the reference surface, plates are formed according to the number of consumers of working measurement tools. Thus, all the plates in their profile turn out to be identical to the matrix, which leads to a uniform measurement. The matrix, in its turn, is subjected to a thorough metrological study.

Then the plate 2 enters the consumer and is installed on the platform 1 with a vertical axis of rotation. The platform with two degrees of freedom 3 is designed as a lever.

Next, platform 3 is connected by a plate 2 mounted on platform 1 by a non-rigid connection, for example, by means of a corundum needle, as is done in the pickup mechanism.

At the same time use the main groove of the plate 2.

Platform 1 is equipped with a graduated gauge 4, the signal of which is fed to the recording device 6. The same device receives a pickup signal, the head of which is installed on an additional track. When the platform 1 rotates at a constant speed "o, the platform 3 rotates at a small speed c in the horizontal plane. We estimate this speed.

Suppose that the distance between each other (the length of the lever) of both platforms is equal to L and the radius of the main groove r depends on the angle φ of rotation of platform 1 as follows:

15

 f,

Zjt

; i)

0

five

0

five

0

where h is the distance between the spirals.

Then, with a sufficient length L of the aforementioned lever of the platform 3, the needle moves practically along the radius of the platform 1. In this case, as follows from (1), the maximum linear velocity V (at the junction point

platform) will be coo, respectively

& jf

the angular velocity of the rotation of the platform 3 with sufficient accuracy can be written

as follows: .- co. Let h

 100 microns, L 1 m, then V m / s, rad / s. Thus, due to the choice of h, bc and L, the linear and angular velocity of the platform 3 can be obtained sufficiently small.

Suppose that the radius of the spiral groove depends on the angle of rotation of the platform 1 according to the quadratic law

g, (2)

where K is a coefficient.

Then, when the platform 1 rotates at a constant soy velocity, we have the angular acceleration of the platform 1 almost constant and, according to (2), is equal to

hco 2K

T

five

0

five

(3)

The linear acceleration of the platform 3 lb is recorded at the point of its connection with platform 2 as

(four)

Varying K by changing the profile of the matrix, the reproducible acceleration can be changed. This acceleration is conveniently determined by the number of revolutions of the n plate made during the reproduction time of the acceleration.

From (2) it follows

to - Јl 2lp

where R is the radius of the plate.

Let, 5 vol., L m, m, co0 33 rev / min. Then, according to (3) and (4), it is possible to estimate the constant accelerations, which

can be maintained for 1 s: in- 0.6 rad / s ,, 6 m / s2. Within 10 s, accelerations can be maintained 10 times less, and within 0.3 s - 3 times greater. Suppose that the radius of the groove depends on the angle of rotation of the platform as follows:

Mr. Go + Gt 8Shf, (5)

where r, rm are constant values.

In this case, the movements, velocities and accelerations (angular and linear) reproduced by platform 1 will be harmonically varied. The frequency range is in this case the proportions and units of Hz. To extend the frequency range, you can use the usual sound recording of harmonic signals of different frequencies (actually up to 40 kHz). In this case, platform 3 oscillates in a vertical plane, in contrast to the cases discussed above, when movement occurs in a horizontal plane. In this case, the frequency characteristics of the devices under study can be automatically removed.

The profiles of the matrix, and therefore the plates are made so that when they rotate, the motion parameters are reproduced corresponding to all points of statistical characteristics (in the case of constant velocities and accelerations) or frequency characteristics (in the case of harmonic displacements, acceleration rates).

Using the pickup 5, information about the angle of rotation and, therefore, about reproducible motion parameters is taken.

This information is removed from the additional track. Thus, the pickup 5, together with the additional track, is a multi-turn rotary encoder of platform 1. This angle can be measured in other ways,

The advantage of the proposed device is the ease of automating the acquisition of statistical and frequency characteristics. For this, it is enough that the profile of the plate allows reproducing all points of these characteristics and ensures the attenuation of transients during transitions from point to point. This greatly increases. the performance of work on metrological support and reduces their cost.

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Claims (1)

JQ Formula of Invention An apparatus for calibrating motion parameter meters, comprising means for reproducing motion parameters in the form of a drive with a vertical axis of rotation, with a platform fixed on its shaft, characterized in that, in order to extend the working range of graduation, the reproducing means is provided with a motion parameter setter made in the form of a disk with spiral profile working for example, using a multi-turn surface with marks of the rotation angle, and ten 83383 about the movement along the abscissa axis is carried out by the signals of the pickup 5, the movement along the vertical axis by the signals of the calibrated instrument 4. The accuracy of the device is determined by the accuracy of fabrication and certification of the die. The certification of the matrix is carried out similarly to the certification of the corresponding standard. In this case, by changing the pattern of the main groove, it is possible to take into account that the platform 3 in the place of its connection with plate 2 does not move along the radius of plate 2, also take into account transients during transitions from point to point of characteristics, set other applicable laws, such as exponential. In addition, the accuracy of metrological assurance increases in the range of small and ultra-small values of motion parameters, which allows extending the working range of calibration. The advantage of the proposed device is the ease of automating the acquisition of statistical and frequency characteristics. For this, it is enough that the profile of the plate allows reproducing all points of these characteristics and ensures the attenuation of transients during transitions from point to point. This greatly increases. the performance of work on metrological support and reduces their cost. 15 25 Invention Formula A device for calibrating motion parameter meters, comprising means for reproducing motion parameters in the form of a drive with a vertical axis of rotation with a platform fixed on its shaft, characterized in that, in order to extend the working range of graduation, the reproducing means is provided with a motion parameter setter spiral profile working or by using the main groove sound track. The pickup signal 5 is fed to a recording device 6, which is a plotter. When building statistical and frequency characteristics also a pickup unit of reproducible size, while the disc is mounted on the platform with the possibility of interaction of its working surface with a pickup unit of reproducible size, mechanically connected with the calibrated meter.