RU1772628C - Method and device for measuring the diameter of logs - Google Patents

Abstract

The invention relates to measuring equipment and can be used in the forestry and woodworking industries and automated devices for measuring and accounting the volume of materials. The aim of the invention is to improve the accuracy of measurements. When the controlled log is moved, the linear displacement sensor generates a sequence of pulses, the number of which is proportional to the linear movement of the log. When he reaches a vertically hung curtain, the log begins to reject it. When the curtain is rotated by a predetermined angle, the end switch is triggered and the pulses cease to flow to the counter. The diameter of the log is calculated by the formula Ctgfaafl, where I is the length of the blind; S - linear movement of the log; f3aA is the predetermined angle of deflection of the curtain. 2 s.p. f-ls, 1 ill. fe

Description

The invention relates to measuring equipment and can be used in the forestry and woodworking industries in automated devices for measuring and accounting for the volume of timber.

A known method for measuring the diameter of logs, according to the maximum deflection angles of the blind, rotated by them around an axis located above the conveyor belt, moving the logs.

The maximum deviation of the blind from the initial (vertical) position occurs at the moment when its end is on the moving log. The deflection angle of the curtain at this moment is

fmaks ZGSS08

-: - arccos (1 -g-)

where I is the distance from the axis of rotation of the curtain to the conveyor belt;

d is the diameter of the end face of the log.

The main disadvantage of this method is the low accuracy of the measurement, which is associated with the fact that the functional dependence of the maximum angle of rotation on the diameter of the log is clearly non-linear.

Consequently, the dependence of the measurement error of these devices on the diameter of the log will have an increasing character.

A known device in which the angle of rotation of the curtain is converted into a sequence of electrical pulses, the number of which at the input of the pulse counter is numerically equal to the diameter of the log. The command to terminate the pulse counting is given by the wayXJ XI GO SUS 00

howling command apparatus when it is reached by a log moved by the conveyor.

However, the known device has low measurement accuracy due to the systematic overestimation of the measurement results.

Closest to the invention is a device for measuring log diameters, comprising two shutters: a measuring one and an elongated one, which presses a limit switch located at the end of the measuring curtain, a relay that functions as an electronic key.

Both shutters rotate together until the measuring shutter is lying on the log, and with further movement of the log only the additional elongated shutter continues to rotate. Due to this, she stops pressing the limit switch, which breaks the relay power circuit, which in turn breaks its contacts at the input of the pulse counter, preventing possible false pulses from entering it.

In this way, the moment when the measuring curtain is lying on the log is fixed.

The known device has the following disadvantages:

the complexity and unreliability of the node fixing the moment when, when passing the log, the end of the measuring curtain is on its surface;

low measurement accuracy associated with the use of a pin-lever system-electrical contact as a pulse source.

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

This is achieved in that the diameter of the logs is determined by the distance by which the log needs to be moved so that it deflects the measurement curtain by a predetermined angle.

This is achieved by the fact that it is equipped with a measuring cycle control unit connected by the first input to the output of the first limit switch, the second to the output of the second limit switch, the output to the first input of the electrode key, the linear displacement sensor of the log being monitored, connected to the second input of the electronic key, one-shot, connected by the input to the output of the first limit switch, by the output - to the second input of the pulse counter, primary information master connected to the third input of the counter

pulses, by a recording unit, the first input of which is connected to the output of the pulse counter, the second - to the output of the second limit switch, and the second limit switch is installed with the ability to interact with the measuring curtain from a plane inclined to the plane of installation of the curtain by a predetermined angle value.

The method is illustrated in the drawing.

The device consists of a shutter 1, a limit switch 2, which fixes the shutter in its initial (vertical) position, a limit switch 3, which fixes the rotation of the shutter by a given angle of the measurement cycle control unit 4, a linear log displacement sensor 5, an electronic key 6, a pulse counter 7 , a setter 8 of primary information, a single vibrator 9 and a registration unit 10.

The essence of the measurement method is that. that the measuring curtain is installed in the plane of the axis of the controlled log, the angle of the curtain deflection is measured with this log moving along its axis, the moment of the curtain deflection is fixed at the given rear angle, the distance S is measured, which the controlled log is moved from the moment the beginning of the deflection of the curtain before it is deflected by a given angle, and the diameter of the log is calculated by the formula

d I - S ctg ass.

where I is the length of the curtain that is linear in the entire measurement range.

To facilitate the hardware-based implementation of the proposed method for measuring the zone of movement of the log after the start of deflection, the blinds are divided into elementary segments of length D S. Then the distance the bottom of which the log is moved during the measurement is determined by the number of elementary segments passed

 -AS

Due to the fact that the diameter of the log is set with a gradation of 1 cm, the value of AS Ad should be equal to 1 cm.

Therefore, the determination of the diameter of the log, according to the proposed measurement method, is reduced to counting the number

elementary segments, on which the log is moved, before the curtain that it deflects from its initial (vertical) position is rotated by a given angle of cut - Then, the obtained value is subtracted from a predetermined value I.

The method using the device is as follows.

In the static position - in the absence of a log in the device alignment and the idle log conveyor - the shutter 1 is in the vertical position and, therefore, the limit switch 2, which fixes the shutter in this position, is pressed, and the limit switch 3, which fixes the deviation of the shutter by a given angle, in a non-pressed state and the linear displacement sensor of the monitored log 5 is turned off.

Simultaneously with turning on the log conveyor, the linear displacement sensor of the monitored log 5 is turned on, which is a type of angle-type transducer - a code whose shaft is connected to the conveyor drive sprocket. Thus moving the conveyor belt, and therefore. and the logs on it are transformed into a sequence of pulses. in, each of which corresponds to the movement of the logs on an elementary segment of the path. The number of these pulses at the output of the sensor 5 is proportional to the distance by which the log is moved.

However, until a log appears in the alignment of the device, the limit switch 2 remains in the pressed state, and the limit switch 3 remains in the unpressed state.

With this combination of signals at the inputs of the angle of control of the measuring cycle - 4, a logical O is established at its output, which, entering the first input of the electronic key 6, locks it, without passing impulses from the linear displacement sensor of the monitored log 5 to the pulse counter 7,

At the moment when the log moved by the conveyor reaches the blind 1 (position 1) and begins to deflect it, the limit switch 2 will be in an unpressed state.

When the limit switches 2 and 3 are not pressed, logical 1s are set on both inputs of the control unit of the measurement cycle 4. Therefore, logical 1 is also installed at the output of the control unit 4, which leads to the opening of the electronic key 6, through which the pulses from the linear displacement sensor of the log being controlled 5 begin to arrive at the counting input of the pulse counter 7. As a pulse counter 7, a reversible counter is used, which subtracts the pulses arriving at its counting input from the previously recorded the number which is entered into the memory of the counter 7 by the preliminary information adjuster 8. Thus, each pulse arriving at the counting input of the pulse counter 7 reduces by one the number previously recorded in the counter.

The pulses arrive at the pulse counter 7 during the entire period of time until the shutter 1. is rotated by a movable log and deviates by a predetermined angle.

The number of pulses received by the pulse counter 7 for a specified period of time is numerically equal to the distance of the axis of rotation of the shutter to the log.

When the curtain rotates to the preset

angle (position II), the limit switch is triggered and logical O is set at the output of the control unit 4. In this case, the electronic key 6 is locked and the pulses from the linear displacement sensor of the monitored log 5 are no longer fed to the pulse counter 8.

This ends the measurement of the diameter of the end of the log.

The number recorded by the counter 7} by

the end of the measurement is equal to the difference between the set number entered into the counter before the start of the measurement and the number of pulses received at its input during the rotation of the shutter 1 from the vertical position to the set angle. This difference is numerically equal to the diameter of the log being moved.

When the limit switch 3 is activated, simultaneously with the signal to lock the electronic key 6, the signal from the second output of this switch receives a signal to the registration unit 10. which reads the readings of the pulse counter.

When the log, continuing to move further, completely leaves the alignment of the device, the shutter 1 will return to its original (vertical) position. In this case, the limit switch 2 will operate and from its second output a signal will be sent to one transmitter 9.

which generates a short pulse, which sets the pulse counter to its initial position (with the number I recorded in its memory).

The measurement cycle is completed.

The log diameter measuring device is provided with a measuring cycle control unit that accurately determines the duration of measuring the movement of the log.

The linear displacement sensor of the log being monitored, which determines the movement of the log per measurement cycle, with the primary information generator, enters into the pulse counter a number equal to the distance from the axis of rotation of the blind to the conveyor belt. The registration unit and the one-shot ensure that the pulse counter returns to its initial state. Both inputs of the measurement cycle control assembly are connected to limit switches. The output of the device is connected to the first input of the electronic key, which is open for the passage of signals arriving at its second input only when logical 1 is at its first input.

A sensor for moving the conveyor belt is connected to the second input of the electronic key. The output of the electronic key is connected to the counting input of the pulse counter, the primary information collector is connected to the installation input of the pulse counter, and the third input of the pulse counter is connected via a one-shot to the second output of the limit switch, which fixes the position of the shutter at the beginning of the measurement cycle, which ensures the installation of the pulse counter in initial state after the curtain returns to its initial (vertical) position.

The output of the pulse counter is connected to a recording unit that records the counter reading on paper or magnetic tape.

Claims (1)

1. The method of measuring the diameter of the logs, which consists in installing a measuring curtain in a plane perpendicular to the axis of the log being monitored, moving the log in the direction of its axis, deflecting the curtain, measuring a deflection angle of the curtain different by the fact that, in order to increase the accuracy of measurements, they fix the moment when the angle of the curtain deflection reaches the set value back, measure the distance S, which passes the controlled log from the moment the beginning of the deflection of the curtain until it is deflected by a given angle, and the diameter d of the log is calculated by the formula fifteen CH-S Ctgfaafl, where I is the length of the curtain. 1. A device for measuring the diameter of the logs, containing a measuring curtain, two limit switches, the first of which is installed in the plane of installation of the shutter, an electronic key, a pulse counter connected to the output of the electronic key, characterized in that, in order to increase the accuracy of measurements, it is equipped with a control unit for the measurement cycle connected to the first input to the output of the first limit switch, the second to the output of the second limit switch, output - to the first input of the electronic key, linear displacement sensor of the log being logged, connected to the second input of the electronic key, single-vibrator, connected input m to the output of the first limit switch, output - to the second input of the pulse counter, a primary information master connected to the third input of the pulse counter, a recording unit, the first input of which is connected to the output of the counter pulses, the second to the output of the second limit switch, and the second limit switch is installed with the possibility of interaction with the measuring curtain in a plane inclined to the plane of installation of the curtain at a predetermined angle value.