SU1002834A2 - Pneumatic device for linear measurements - Google Patents

Description

one

The invention relates to a measurement technique and can be used to measure linear dimensions.

According to the main author. St. No. J2} 67k a pneumatic linear measurement device is known, comprising a flow chamber communicated with an air network, an inlet throttle, an outlet measuring nozzle and means for measuring pressure in the chamber in the form of a rotometric tube with a throttle whose inlet communicates with the flow through camera, and the output - with the atmosphere j 1.

However, the known device does not allow the statistical processing of measurement results necessary for monitoring the state of the technological process.

at

The aim of the invention is to extend the functionality

by fixing the dispersion limits of controlled sizes.

The goal is achieved by the fact that the device is equipped with two additional rotometric tubes and a memory unit made in the form of a differential diaphragm actuator with a rigid center, a measuring cavity communicated with the measuring nozzle and a counterpressure cavity

10 and two communicated with additional rotometrichesky tubes of converters of the nozzle-damper type with floating dampers mounted for movement by rigid

15 center; the first is from the nozzle with a pressure drop in the measuring cavity, and the second to the nozzle with increasing pressure in the measuring cavity.

20

The drawing shows the proposed device.

Pneumatic device for li-. The measurement includes a flow chamber 1, a throttle 2 at the entrance to it, a measuring nozzle 3 at the exit, a rotometric tube connected to the flow chamber and equipped with a choke 5 at the exit, po1; an emetric tube 6 with a choke 7, a rotometric tube 8 with a choke 9, Differential diaphragm actuator 10 with membranes 11 and 12, rigid center 13 membranes, measuring cavity 14 and cavity 15 counter-pressure, transducers with nozzles 1b and 17 and floating dampers 18 and 19 installed in bearings 20 with the possibility of displacing a rigid center 13. damper 18 —from nozzle 16 when pressure in measuring cavity 1 drops, and damper 19 — to nozzle 17, an increase in pressure in measuring cavity 14. A zero control throttle 21 is installed in the counterpressure cavity 15. The rotametric tube 4 is equipped with the marks 22 and 23, respectively, of the lower and upper limits of measurement, the rotametric tube 6 with the mark 24 of the lower limit of measurement, and the tube 8 with the mark 25 of the upper limit of measurement. The output of the stabilizer 2b is connected to the inlet of the tube 4 through the throttle 2, the inlet of the tube 6 through the throttle 27, the inlet of the tube 8 through the throttle 28 and the cavity 15 of the perforation. The measuring nozzle 3 communicates with the measuring cavity 14 through the valve 29, the nozzle 16 communicates with the tube 6, the nozzle 17 with the tube 8 Differential diaphragm actuator 10 and the nozzles 16 and 17 with the flaps 18 and 19 form a memory unit, and the rotometric tubes 6 and 8 provide Visualization of the values recorded by the memory block using the floats 30-32 moving along the rotometric tubes 4, 6 and 8. The device operates as follows. The beginning of the measurements on rotametric tubes 4, 6 and 8 are 22-25, and in the differential diaphragm actuator, the dampers 18 and 19. To do this, instead of the controlled part 33, the installation measures, respectively the upper and lower limits of the floor tolerance, as well as the nominal size. In each steady state, the appropriate brands are combined with the position of the floats in the tubes. In addition, when the nominal size is installed, the valve 29 is opened, using the throttles 21, the rigid center 13 is set to the middle position and the shutters 18 and 19 are pressed to it. For measurement, the test piece 33 is placed on the measuring position and compressed air is supplied from the pressure stabilizer 26. In accordance with the controlled size and, therefore, the gap S-2. between the measuring nozzle 3 and the part 33, the floats 30-32 in the rotometric tubes 4, 6 and 8 will occupy a certain position relative to the marks 22-25. In that case, if the actual clearance of $ 2 remains equal to the tuning, all three floats 30-32 are at the same level relative to the brands 22-25. In case of deviation of the actual clearance ST. P the larger side (the part size decreases) the pressure in chamber 1 and cavity 14 decreases, the float in tube 4 drops relative to the initial position (approaching the lower border of the tolerance field, the hard center 13 moves to the left (according to the drawing and moves the gate 18 in the direction of increasing the gap S to a value equal to the gap 5.2. The float 31 of the tube 6 will occupy the same position as the float 30 in the tube 4. Now when removing the test piece from the position of the float in tube 4 will go beyond the limit of mark 22, and the float 31 in tube 6 will lock in n The position corresponding to the controlled size, as in this case the valve 29 will close and the gap 5-jj will remain unchanged, corresponding to the shifted position of the valve 18. The position of the float 32 in the tube 8 will remain the same, corresponding to the installation gap of $ 4 In case of deviation of the actual gap ST In the lower side C, the size of the part increased the pressure in chamber 1 and cavity 14 increased, the float in tube 4 would rise relative to the initial position, approaching the upper limit of the tolerance field, rigid Center 13 smes51

Tits to the right (according to the drawing and, detached from the end face of the valve 18, will move the valve 19 in the direction of reducing the gap 54 to a value equal to the gap 5g. The float 32 of the tube 8 will take the same position as the float 30 in tube A. The measuring position of the float .30 in the tube will again go beyond the limit of mark 22, and the float 32 in the tube 8 will lock in the position corresponding to the monitored dimension, since the valve 29 will close again and the gap S -; j will remain unchanged, corresponding previous pr This means that the floats 31 and 32 in tubes 6 and 8, having dispersed to different sides from the middle position, will record the actual deviations (process dissipation field) of controlled sizes inside the tolerance field and the position of these deviations from the limits of the tolerance field.

Obviously, if, in the process of further measuring the batch of parts, their actual dimensions will lie within the in-dispersed dispersion field, no change in the position of the floats 31 and 32 occurs, and the actual dimensions are visible from the position of the float 30 in tube k,

If, in the measurement process, the controlled dimensions are beyond the limits of the established dispersion field, the floats 31 and 32 (one or both) will react to these measurements and show new limits for the technical dispersion field.

If in the process of control one of the floats 31 or 32 turns out to be 0283 6

This is indicative of the increased danger of marriage and the need for adjusting the process. 5 Thus, the presence of a memory unit with rotametric tubes gives the device a new quality — the ability to use it not only as a meter, but also the pneumatic 10 of a static statistical analyzer of the state of the technological process.

Claims (1)

1. Copyright. Certificate of the USSR, №72167, cl. G01 13/02, 1971.