SU1366868A1 - Device for measuring linear dimensions - Google Patents

Abstract

This invention relates to instrumentation technology. The purpose of the invention is to increase measurement accuracy. In the process of measuring the linear size of the product, the measuring rod with the core 5 of the transformer sensor 1 moves, and a signal proportional to the monitored size is supplied from the output windings of the sensor 1 through the switch 6 and the first detector 9 to the first input of the subtraction unit 10, to the second input through the second detector 1I is applied to the rectified output voltage of the generator. The signal from the output of the subtraction unit 10 is fed to the input of the amplitude analyzer 12. Depending on the magnitude of this signal, proportional to the monitored size, the corresponding threshold element of the amplitude analyzer 12 is triggered, the output signal of which is fed to one of the inputs of the corresponding element And block 13, from whose outputs the signal enters the sorting device, which performs automatic sorting of products into the appropriate size groups. 1 hp f-ly, 2 ill. S cl

Description

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The invention relates to instrumentation engineering and can be used in multi-position devices for automatically controlling and sorting products according to linear dimensions.

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

Figure 1 shows the functional diagram of the device; figure 2 - differential transformer sensor.

A device for measuring linear dimensions contains a series of differential transformer sensors 1 according to the number of measurement channels (for example, 6 sensors) each having two catupgie 2 and 3 with INPUTS and output windings. On the measuring rod 4 of sensor 1, a core 5 is installed with an initial axial displacement of 1Q in the middle of the length of one core relative to the center of coils 2 and 3.

The input and output windings of coils 2 and 3 of sensor 1 are connected to inputs and outputs of switch 6, while the input windings through switch 6 and regulating element 7 are connected to the first output of generator 8, and the first detector is connected to output windings 9 first input block 10 subtract. The second input of the subtraction unit 10 is connected via the second detector 11 to the second output of the generator 8.

I.

The device also contains an amplitude analyzer 12, the input of which is connected to the output of the subtraction unit 10, the unit 13 of the three-input elements And, and the synchronizer 14 connected to the control input of the switch 6. 1

12 amplitude analyzer consists

from a number of threshold elements adjusted to the size limits of the sorting groups (in this example, the sorting is carried out into 5 dimensional groups).

The first inputs of block 13 of the three-input elements And are connected to the output of the synchronizer 14, and the second - with the outputs of the analyzer 12 amplitude. The third inputs of the block 13 elements And connected to the code of the threshold element 15, the input of which is connected through the first detector 9 and switch 6 to the output windings of the sensors

The ratio of the number of turns of the windings of the coils 2 and 3 of the sensor 1 is selected from the condition.

Wj + w;

From / - ±

.... where w w, -

Wai- uk.

 ..iv - -

the number of turns of the primary winding of the second coil; the number of turns of the secondary winding of the first coil;

0

five

0

five

0

five

K f (- 21j 11

0

coefficient depending on the ratio of the numbers of turns of the secondary winding of the second coil (v) and the primary winding 1 c 55

ki of the first coil ((with w, J; initial axial displacement of the middle of the core 5 relative to the center of coils 2 and 3;

sensor measurement range 1.

Such a state of the number of turns of the windings allows the linear portion of the positive branch of the output characteristic of sensor 1 to be approximately doubled.

In this case, the primary winding of the first coil 2 of the sensor 1 (Fig. 1) is connected according to the secondary winding of the second coil 3, and the secondary winding of the first coil 2 is connected opposite to the primary winding of the second catum cell 3. This connection of the windings significantly reduces the effect of changes in external conditions on the measurement results.

The device works as follows.

The controlled products are alternately supplied with an automatic transport device (not shown) at the measurement positions equipped with transformer sensors 1.

In the process of measuring the linear size of the product, the measuring rod 4 with the core 5 of the transformer sensor 1 moves and a signal proportional to the monitored size is supplied from the output windings of the sensor 1 through the switch 6 and the first detector 9 to the first input of the subtraction unit 10, to the second input of which through the second detector 11 is supplied with an intermediate variable voltage

8. Comparison of these signals can significantly reduce the effect of changes in external conditions on the measurement results.

The power supply of sensors 1 of the core; is emitted from the generator 8 through the switch 6 and the regulating elements 7 included in the circuit of the windings of the sensors 1. This allows you to change, if necessary, the angle of inclination of the characteristics of each sensor.

. Since the output characteristics of individual sensors can have different angles of inclination, with the help of regulating elements 7, the angle of inclination of the characteristics of all transformer sensors I can be set the same, as a result of which the sensors become interchangeable and can be alternately connected to a common measuring circuit using an automatic switch 6

The signal from the output of the block. A 10 subtraction is fed to the input of the amplitude analyzer 12. Depending on the magnitude of this signal, proportional to the monitored size, the corresponding threshold element of the amplitude analyzer 12 is triggered, the output signal of which is fed to one of the inputs of the corresponding element AND block 13. The inputs of the block 13 elements And are also short pulses from the synchronizer 14 to eliminate noise, arising from the operation of the switch 6, and the signal presence of a fragment, coming from the output of the threshold element 15.

The output signal of the element And the block 13 appears only if there are three input signals, which ensures reliable stability of the measurement circuit from the effect of industrial noise.

The signals from the outputs of the block 13 of the elements And go to a sorting device (not shown), which performs automatic sorting of products into the appropriate size groups.

Claims (1)

1. An apparatus for measuring linear dimensions, comprising a series of differential transformer sensors five according to the number of measurement channels having each core and two coils with two pairs of input and output windings connected in series, the switch, the outputs and inputs of which are connected in pairs with the input and output sensors windings, the generator, the first output of which is connected to the switch input, a subtractor unit, a first detector connected between the switch output and the first input of the subtractor unit, and an amplitude analyzer whose input is connected to the output of the subtraction unit, characterized in that, in order to improve the measurement accuracy It is equipped with a synchronizer connected to the control input of the switch, a block of three-input elements AND whose first inputs are connected to the synchronizer output, and the second to the amplitude analyzer outputs, a second detector connected between the second generator output and the second input of the subtractor, the threshold element connected between the output of the first detector and the third inputs of the block of the elements I, and the regulating elements included in the circuit of the windings of the sensors. 2, The device according to claim 1, of which is the first winding of the first coil of each transformer sensor connected to the coil five 0 The secondary winding of the first coil is opposed to the primary winding of the second coil, and the ratio of the number of turns of the windings is chosen from the condition 11- .t v ,, + w. -2 to where w I-f l 11Irf - The number of turns of the primary winding of the second coil; w, j is the number of turns of the secondary winding of the first coil; K f () is the coefficient dependent W, 1 FROM the ratio of the number of turns of the secondary winding of the second coil (WQ,) and the primary winding of the first coil (w); the initial axial displacement of the middle of the core relative to the center of the coils; 1 - sensor measurement range. about 1