SU1174740A1 - Device for calibrating testing of pointer-type devices with circular scale - Google Patents

Abstract

A device for testing gauge instruments with a circular scale, which contains a node for setting and fixing exemplary values of the measured value, a readout head with a centering unit, a unit of single angular increments sequentially arranged by the illuminator, an image analyzer, a block of photodetectors, and a registration unit with recalculated schemes with recalculated schemes. that, in order to improve the accuracy and performance of measurements, the reading head is made in the form of two coaxially mounted and mated with one another by means of rotation guides of the drums, one of which is fixed and the other rotatably with respect to a common axis, a lens mounted coaxially with the drums and mounted on the end wall of the fixed drum facing the adjustable device, optical compensators designed for imaging strokes of the scale and the working section of the arrow being turned when-; boron, two image analyzers made in the form of modulating discs, one of the discs is mounted on the opposite end of the drum rotatably mounted with respect to the instrument, the other modulating disc is fixed in the immediate vicinity of the first one, the spiral in the first disc is in the first disc the diaphragm, on a circle with a p-radius equal to the removal of the image of the working section of the arrow of the instrument being turned on from the center of its scale, is you (L is full of an annular diaphragm, on a circle of radius, The radial diaphragm is made to remove the center of the scale bar of the device being scanned from the center of the disk, the second disk opposite the spiral diaphragm of the first disk is KpecTooiS - there is a different diaphragm, opposite the annular diaphragm of the first disk - the radial diaphragms, the number and location of which corresponds to the number and location of controlled points scales, radius, equal to i distance radiosno1 (diaphragm; the first disk from its center, on the extension of the longitudinal axes of the slits, forming a cruciform diaphragm , radial diaphragms are made, and the outputs of the registration unit scans are designed to be connected to the inputs of the computing device.

Description

one

The invention relates to a measurement technique and can be used in metrology for testing dial gauges with a dial scale, such as dial gauges.

Devices are known for determining the error of the indications of dial gauge instruments, containing a light source, a reading head, a rotating drum-shaped drum head with a slit diaphragm on the side surface, a photodetector installed inside a drum, and an instrument for recording measurement results of C 1 "

The disadvantages of these devices are the low speed and poor quality of verification, due to the fact that the indicator is calibrated with the protective glass removed and the arrow removed.

The closest to the invention of the technical essence is a device for calibrating dial gauge instruments containing a node for setting and fixing exemplary values of the measured value, a reading head with a centering unit, a unit of single angular increments sequentially located by the illuminator, image analyzer, unit photodetectors, and a registration unit with scaling circuits C2i /.

The disadvantages of the known devices are the relatively low accuracy and performance of measurements due to eccentricity due to the design used; the centering unit and applying the static verification mode, in which the measuring rod of the indicator being tested is stopped at controlled points.

The purpose of the invention is to improve the accuracy and performance of measurements. ;

This goal is achieved by the fact that in a device for calibrating dial gauge devices containing a node for setting and fixing volume values of a measured value, a reading head with a centering unit, a sensor of unit angular increments sequentially arranged by the illuminator, image analyzer, block 402

a set of photodetectors, and a recording unit with scaling circuits, the reader head is made in the form of two coaxially mounted and conjugated one to another through rotation guides of the drums, one of which is fixed and the other rotatably about a common axis,

a lens mounted coaxially with the drums and mounted on the end wall of the fixed drum facing the calibrated device, optical compensators designed to form images of the scale lines and the working section of the arrow of the device being turned, two image analyzers made in the form of modulating disks, one

of the discs mounted on the opposite with respect to the testable device of the end of the drum, mounted rotatably, another modulating disc is installed

motionless in close proximity to. first, in the disk in the center there is a spiral diaphragm, on a circle with a radius equal to the image of the working section of the arrow of the instrument being turned from the center of its scale, a ring diaphragm is drawn, on a circle with a radius equal to the center of the stroke of the scale being scanned

the device from the center of the scale is made of diaphragm, in the second disk opposite to the spiral diaphragm of the first disk there is a cross-shaped diaphragm, opposite to the annular

the diaphragms of the first disk — the radial diaphragms, the number and location of which corresponds to the number and location of the controlled points of the scale, radially equal to the radial diaphragm distance of the first disk from its center, on the continuation of the longitudinal axes of the slots forming the cruciform diaphragm, the radial diaphragms are made, and

outputs of recalculation diagrams of the re-t block.

The hysteresis is intended to be connected to the inputs of a computing device.

Figure 1 shows the functional diagram of the device for calibration of dial gauge; Fig. 2 is a simplified structural diagram of a matching head; in FIG. 3, a rotating image analyzer in FIG. 4 is a fixed image analyzer; in Fig. 5, a theoretical view of the photoelectric signals from the outputs of photodetectors installed in the block behind the radial diaphragms (a) and numerical equivalents of the desired angles formed in the corresponding recalculation diagrams (b in Fig. 6 is the location of the desired angle with reference to the scanner's instrument; Fig. 7 shows an example of the mutual arrangement of the image of the footer (base) of the instrument's instrument and the cross-shaped diaphragm; Fig. 8 is a theoretical view of the photoelectric signals from the photodetector outputs the manniki installed in the block behind the edges of the target of the cruciate diaphragm located along the abscissa axis obtained by scanning the spiral diaphragm and the corresponding numerical equivalents. A device for calibrating switch instruments consists (figure 1) of a reading head 1, node 2 setting and fixing exemplary values of the measured value and the registration unit — verification results, containing three channels for processing the measurement information, each of which consists of schemes 3 for generating information signals and scaling cs m 4, 5 and the computing device with digital display and tsifropechatyu. The read head 1 consists (figure 2) of a stationary 6 and rotating 7 state drums located coaxially and mated to each other by means of ball bearings 8. A lens 10 is mounted on the end wall of the drum 6 facing the dial of the turn-dial instrument 9, and the optical axis is aligned with the axis of the drum 6. On the same end wall, lamps 1 1 are mounted, which form a lighting fixture located concentrically with the axis of the drum 6. On the opposite side of the center wall of the drum 6 is an optical compensator 1 2, made, for example, of two glass rings arranged concentrically with the axis of the drum 6. The compensator 12 is designed to position in one plane the images of the lines: the scale, the arrow and its base (footer) given by the objective 10 (dial, arrow and its base at the switch instruments are structurally located in different planes). To arrange the images of the dial, the hands and its bases (footer) in one plane, the shape of the compensator rings 12 is chosen so that the rays that form the image of the footer ( the closer element to the lens 10), bypassing the compensator 12, the rays that build the image of the dial (the element most distant from the lens) pass through both rings, and the rays that build the image arrows only through one. To remote from the lens face. An image analyzer, made in the form of a disk 13, which can rotate with the drum 7 from an electric motor 14, for example, with the help of a friction wheel 15, is rigidly attached to the wall of the drum 7. An image analyzer located in the vicinity of the analyzer 13 is also made in the form of a disk 16 and mounted on the fixed part of the read head. On disks 13 and 16 there are transparent masks on an opaque background (light paths). In the center of the disk 13 is located. a spiral diaphragm a (fig.Z), representing, for example, a portion of an Archimedes spiral whose pole is located on the optical axis of the lens 10. With the diaphragm a, the cruciate diaphragm a (Fig.4) is located in the center of the disk 16. The center of the diaphragm and also located on the optical axis of the lens 10. The width of the diaphragms a and a is chosen as small as possible from the point of view of reliable reception of the flux through them. The diaphragms a and a are designed to obtain information about the mutual displacement of the axis 0 of rotation of the arrow of the pointer instrument being turned and the axis O of rotation of the reading head (the axis of rotation of the drum 7). On a circle with a radius equal to the distance of the center of the working section of the image of the arrow of the turned needle instrument from the axis of rotation of its arrow, on the disk 16 there are centers of radial diaphragms in, the number and location of which

corresponds to the number and location of the controlled points of the scale. The longitudinal size of these diaphragms limits the length of the used section of the arrow image, and the width of these diaphragms is equal to the width of the working section of the image of the arrow. On disk 13 opposite diaphragms, a transparent ring is made in, providing access to the luminous fluxes to diaphragms. The diaphragms allow you to measure the moments when the arrows in the instrument being scanned are at controlled points on the scale.

On a circle with a radius equal to the distance of the center of the image of the stroke of the scale of the instrument being scanned from the center of its scale 0, on disk 13 there is a center of one radial diaphragm c, and on disk 16 on the extension of the longitudinal axes forming a cross-shaped diaphragm of the slots there are four radios of diaphragms . The longitudinal size of the diaphragm is equal to the length of the image of the stroke of the scale of the instrument being scanned, the width of the diaphragm with is equal to the width of the image of the stroke of the scale, and the length of the diaphragms with is chosen about the double distance between adjacent strokes of the scale. These diaphragms are designed to obtain information about the mutual displacement of the center of the scale of the instrument being scanned and the axis of rotation with the scale of the head.

The read head 1 also includes a centering unit and a sensor of unit angular increments.

The centering unit can be made, for example, in the form of a centering cone 18, which is pressed against the rim of the instrument being turned 9 by the spring 19, and is intended to base the instrument being scanned at the measurement position.

The unit of unit angular increments may, for example, consist of an illuminator 20, a group of alternating transparent and opaque strokes d forming a radial raster (FIG. 3) of a radial diaphragm d made on the analyzer 16 opposite the strokes d and having the same length and width (FIG. , 4), and the corresponding photodetector installed behind the diaphragm d in the block of photodetectors 17. The number

strokes d is selected based on the required discreteness of the reference angles of rotation of the drum 7 of the read head.

The stripping head 1 is mounted on the base 21 by means of a bracket 22, Ea of the base 21 is also provided with a bracket 23 for fastening a rotating device 9 and an electric motor 14.

The type and design of the unit for specifying and fixing exemplary values of the measured quantity 2 (Fig. 1) depends on which physical quantity is intended for measuring the turn-point gauge. For example, when calibrating watch-type indicators, it contains a stop 24 (Fig. 2), moving in straight-line guides 25, and an exemplary linear displacement sensor 26 with a digital output. In this case, the measuring tips of the instrument 9c of the reference sensor 26, which are arranged coaxially with each other, are in contact with the working surfaces of the stop 24.

The information signal generation circuits 3 are designed to form start-stop signals from the photoelectric signals from the outputs of the photodetector unit 17 to control the operation of the corresponding diagonal circuits 4, as well as the counting pulses. They can be executed for example from the Schmitt trigger connected in series, the differential circuit and the diode limiter.

The scaling circuits 4 use signals from the sensor of single angular increments of the reading head 1 and the sensor from the task setting unit and fixing the sample values of the measured value 2 after their corresponding processing in schemes 3; as counting pulses;

Computing device 5 according to information accumulated in scaling schemes 4 calculates eccentricity corrections at each controlled point for which it preliminarily calculates the coordinates of the center of the scale and the axis of rotation of the arrow of the device being turned relative to the axis of rotation of the matching head.

The device works as follows. The centering cone 18 is retracted to the extreme right position (Fig. 2), the rotatable device 9 is mounted on the bracket 23, the cone 18 is pressed by the spring 19 to the rim of the device 9 and thus provides a rough centering of the instrument's scale relative to the axis of the read head. Next, an electric motor 14 is turned on, which, with the help of a friction wheel 15, drives the drum 7 of the read head, and the device for calibrating dial gauges starts to work in the eccentricity correction mode. The calculated ratio for determining the eccentricity corrections is as follows, where; to the proportionality coefficient; coordinates of the center of the scale. the instrument to be checked relative to the axis of rotation of the reading head; the coordinates of the axis of rotation of the arrow of the device being turned relative to the axis of rotation of the reading head radius of a circle, on which the centers of di fragments are located with i the radius of a circle, on which the centers of di fragments in are located, the values of the angles of rotation of the arrow of the device being turned relative to its initial (zero) position is fixed in the system of coordinates, the center of which is located on the axis of rotation of the readings of the head. The ratio in square brackets expresses the magnitude of the correction in angular units (radians), and the sign is taken in the case where x.x is x and when the sign is x when xc x. To obtain the value of the correction in units of the measured value, the value of the correction in radians is multiplied by the proportionality factor, which is equal to the ratio of the price of one full turn of the arrow in measured values to 27 /, for example, for hour-type indicators - to 1000 micrometers. In formula (1), the values of RU are known, and Rf, and / "is the current value of the angle, for fixed values of which the eccentricity corrections are determined. X values Y- to be determined. WL 0 is different for each of the turnable gauge devices. The information necessary to determine the values of Hz, and Ush, is obtained by analyzing the signals obtained when switching light fluxes by means of diaphragms (Fig. 3), at the outputs of the corresponding photodetectors of block 17 (Fig. 2). These receivers are mounted behind each of the diaphragms with. The analyzer 16 of the image is installed in such a way that when the scanned device is installed in the bracket 23, diaphragm c images get images of diametrically opposed strokes of the scale of the scanned device, for example, dp devices with 100 divisions of O, 25, 50 and 75th strokes of the scale. When the disk 13 is rotated, the diaphragm c sequentially scans the fields of view of the diaphragms c. When the diaphragm C enters the region of one of the diaphragms C, the luminous flux begins to pass to the corresponding photodetector} when the diaphragm passes from the dash image, this luminous flux decreases, and when it leaves the hatch region, v- again increases and then when the aperture leaves from the area of the diaphragm with completely interrupted. Thus, against the background of the signal from diaphragm c, an impulse from the corresponding stroke appears (Fig. 5a), and the peak of this impulse corresponds to the moment when the longitudinal axes of the diaphragm c and the stroke image coincide. In the absence of an eccentricity between the axis of rotation of the analyzer 13 and the center of the scale of the turnable switch instrument (for example, for devices with 100 scale divisions, the intersection point of the diameters on which O, 50 and 25 lie, 75th strokes

scales) sequential alignment of the axis of the diaphragm with the midpoints of the corresponding image of strokes occurs when the analyzer 13 rotates at equal angles of 90. In the presence of eccentricity, the equality of these adjacent angles to each other is violated. By analyzing three consecutive adjacent angles, the coordinates X and y are determined. In this case, in accordance with the information signal generation schemes 3 (FIG. T), start-stop impulses are formed, limiting the time intervals between the vertices of the corresponding impulses from the dashes, which are then filled with counting impulses from the sensor unit angular increments and, thus, in the corresponding scaling schemes 4, the numerical equivalents of the above mentioned adjacent angles are formed, in which the values of x and y are calculated in the computing device 5.

U)

where, N25.50, Nso, 7S are numerical equivalents of fixed angles between directions, respectively. O- and 25-gb 25-and 50-th and 50-and 75-g strokes of the scals (Fig. 6),

N j (, () is the numerical equivalent of 360 angle.

The information necessary to determine the values of X p and y is obtained by analyzing the signals obtained when switching light fluxes by means of di 1 fragments a and a (fig.3 and 4) at the outputs of the corresponding photodetectors of block 17 (figure 1). If there is an eccentricity of the axis of rotation of the drum 7 of the reading head relative to the axis of rotation of the arrow of the device being turned, the image of the footer (base) of the arrow is located non-axially with the center of the cross-shaped diaphragm (Fig. 7a). Therefore, the length of the illuminated sections of the edges of the slots forming a cruciform diaphragm not covered by the image of the footer. Stoiki, unequal. It's obvious that

with an increase in the optical system equal to 1, the half-difference of the lengths of pairs of these above illuminated sections, S lying on the same slit of the cruciform diaphragm, give the desired coordinates Xp and y. (the coordinate axes of the adopted reference frame are oriented along the slits of the cruciform diaphragm).

To determine the lengths of these illuminated areas, a spiral diaphragm a is designed (FIG. 3).

5 and photodetectors installed in block 17 (FIG. 1) behind each of the four edges of the slits of the cruciform diaphragm. When the analyzer 13 is rotated, and consequently, the spiral diaphragm, the latter scans the above sections linearly along each of these 3 astcas, while turning the analyzer 13 with the spiral diaphragm a

 one turn, the axis of the helix is displaced along any of the rays, including along the received axes of coordinates (the longitudinal axes of the slits of the cruciform diaphragm a) by an amount

30 is equal to the given step of the helix g.

When the analyzer 13 rotates, at the outputs of photodetectors installed in block 17 beyond the edges of the slits of the cruciate diaphragm, photoelectric pulses periodically appear, the duration of which, measured at the base of the latter, is proportional to the sum of the width of the spiral diaphragm

and the length of the combined portion of the corresponding edge of the cruciform diaphragm. Taking into account the constancy of the width of the spiral diaphragm along its entire length, the difference in the duration of the pairs

The five above-mentioned photoelectric pulses, corresponding to the edges of the cruciform diaphragm lying on the same slit, are proportional to the desired coordinates Xc, y ".

0

In scaling circuits 3 (Fig. 1), numerical equivalents of the lengths of the illuminated sections are formed, for which the corresponding information signal generation circuit 3 generates time intervals corresponding to the duration of the photoelectric pulses, which are filled with counting pulses from a sensor of unit angular increments (Fig. 8). The formulas for x and y are of the form. - “idr t () - (N, .- N ,,) -, where NX x are numerical equivalents of the values of the illuminated parts of the edges of the slits of the cruciform diaphragm, lying respectively on the positive and negative semiaxis along the abscissa axis; N, Ny-- the same, but along the axis of hordes and nat. When the device operates in the mode of determining the eccentricity corrections, the arrow of the instrument being turned is in a position in which its image does not fall into the field of the diaphragm s and a, which is easy to implement (for example, as shown in Fig. 7). After the set of information necessary for the calculation of eccentricity corrections, the devices start working in the calibration mode of the needle instrument. At that, the drum 7 (FIG. 2) can be stopped and the node for setting and fixing the sample values of the measured value 2 (FIG. 1) turns on. For example, when calibrating instruments for linear measurements (for example, dial gauges), the stop 24 (Fig. 2) moves in directions 25. At this, the stop 24 moves the measuring rod of the turnable arrow instrument 9 and the arrow of the latter rotates. Simultaneously, the linear displacement sensor 26 receives information about the magnitude of the linear displacements of the stop 24, and hence the measuring rod of the testable device 9. The image of the arrow while rotating the latter intersects diaphragms in and out at the outputs of the photoreceivers installed in block 17 for each From these diaphragms, photoelectric pulses appear, the vertices of the latter corresponding to the combination of the longitudinal axes of the image of the working section of the arrow and the corresponding diaphragm c. . In the corresponding schemes for generating information signals 3 (FIG. 1), time intervals are formed between the pairs of the above photoelectric pulses received from the diaphragm pairs in the limited area of the dial gauge, and using signals from the sensor 26 in the corresponding scaling schemes 4 (Fig. 1) are determined corresponding to these time intervals of the amount of displacement of the measuring rod of the rotating instrument. To the obtained values of the displacements in the computational device 5 (Fig. 1), the algebraic values of the corresponding eccentricity corrections are added and the nominal values of the readable instruments are subtracted from the sums received. The differences obtained give errors in the readings of the scanned instruments at controlled points. The values of these errors are recorded in the verification results recording unit. The embodiment of the read head disclosed in the invention makes it possible to increase the accuracy of measurements by introducing corrections for eccentricities and to increase the speed of the device by eliminating the stops of the instrument being scanned at controlled points.

Fig. /

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Claims (1)

DEVICE FOR TESTING ARROWS WITH A CIRCLE SCALE, containing a unit for setting and fixing sample values of a measured quantity, a reading head with a centering unit, a unit of incremental angular increments, sequentially arranged illuminator, image analyzer, photodetector unit, and a registration unit with counting circuits, characterized in that, in order to improve the accuracy and performance of measurements, the read head is made in the form of two coaxially mounted and interfaced with one another of the guides of rotation of the drums, one of which is fixedly mounted, and the other with the possibility of rotation relative to the common axis, a lens mounted coaxially with the drums and mounted on the end wall of the fixed drum facing the device to be verified, optical compensators designed to form images of scale strokes and the working area of the arrow of the person to be verified; a bur, two image analyzers made in the form of modulating disks, one of the disks is mounted on the opposite to the verified instrument end of the drum mounted for rotation, the other modulating disk is mounted motionless in the immediate vicinity of the first, in the first disk in the center there is a spiral diaphragm , on a circle with a radius equal to the removal of the image of the working section of the arrow of the device being verified from the center of its scale, an annular diaphragm is made, on a circle with a radius equal to ud radial diaphragm is made in the second disk opposite the spiral diaphragm of the first disk, a cross-shaped diaphragm is made in the second disk, radial diaphragms are opposite the annular diaphragm of the first disk, the number and location of which corresponds to the number and location of controlled points of the radius equal to the distance of the radial diaphragm of the first disk from its center, on the extension of the longitudinal axes of the slots forming a cross-shaped diaphragm, are made radially e aperture, and the outputs of counting circuits for the registration unit designed podkpyu-, cheniya to the inputs of a computing device. 1 1174740 2