SU872974A1 - Device for measuring characteristics of fibre distribution along the length - Google Patents

Description

(54) DEVICE FOR MEASUREMENT OF PACPPEJAIELENIUM FIBER FEATURES OF LENGTH

The invention relates to devices for monitoring the parameters of fibers in a textile industry.

A device comprising a radiation source, a light guide, a luminous flux switch, an adjustable slit diaphragm, an aperture diaphragm, and a photodetector mounted along the luminous flux, a clip for, is known. sample mounting with a drive, an additional terminal with spring-loaded jaws, a synchronous signal switch and a logarithmic signal converter connected to a photodetector, a feedback circuit connected to the radiation source to

The closest in technical essence to the present invention is a device for measuring the distribution characteristics of fibers along a length, comprising a radiation source, a clamped sample of fibers with an actuator, an optical system, aperture diaphragm and aperture, a photodetector, and a computing device. In this device, the measurement of the characteristics of the distribution of fibers along the length of the axis is realized by scanning the fiber bead with a light raster beam, processing the photometric information and converting it into characteristics of the distribution along the length. The device contains a clamp drive

10 for fastening the sample and a light beam switch that guides alternately to the photoreception light transmitted through the sample or bypassing the sample through the light guide. The drive for clamping the sample consists of a carriage on which the sample is fixed, guides for the affordable movement of the carriage, a screw pair for moving the carriage, a gearbox having a pair of replaceable gears for desparing the liver of different ranges of movement of the carriage, two working motors and reverse stroke, two Electromagnetic clutches for switching on the working and reverse stroke, the carriage stopping device in the extreme positions, consisting of a screw pair, kinematically connected with a light flux switch, Micro switches for coarse stop, cam and microtransfer of exact stop. The switch is a luminous flux in the form of a disk rotating in the focal plane of the lens. Along the edge of the disk, uniformly alternating, are rectangular protrusions and depressions. Under each protrusion below the depression area there is an opening for the transmission of the light flux through the light guide. At the moment the light flux passes through the fiber, the light flux directed to the sample overlaps in the focus of the lens with another protrusion. While the cavity is in the focus of the lens, the luminous flux through the sample is open, and the luminous flux through the light guide is blocked. To one of the required ranges of movement of the clamp with the sample corresponds to the same strictly defined number of light flux switches. The number of switches is determined based on the specified measurement accuracy. The error in measuring the fiber length distribution characteristics in this device largely depends on the accuracy of moving the clamp by one sample for one switch cycle of the light flux switch (scan step; ani 1 and the accuracy of clamp setting to its original position, since for calculating the geometric characteristics of the fibers measure the dependence of the number of fibers in the sample cross section as a function of the distance from the clamp line to the controlled cross section. no more than +0.05 mm, and the limit of the allowable reduced error of the clamp with the sample by an amount equal to 10% of the measured range, not more than ± 0.05% .23 The disadvantages of the known devices are the decrease in the measurement accuracy and the complexity of the design of - due to a large number of links in the kinematic drive chain and the exact carriage stopping mechanism in the source position | as well as due to the design in the fiber as a bypass channel for the light flux. The purpose of the invention is to improve the accuracy of measuring the characteristics of the distribution of fibers along the length and simplify the design. This goal is achieved by the fact that in a device for measuring the characteristics of the distribution of fibers along the length, containing a radiation source, a specimen clamp with a drive, an optical system for forming a light flux, a light switch, an adjustable slit diaphragm, an aperture diaphragm, a photodetector, installed along the light path flow, as well as the mechanism of parallelization of fibers and computing device, the clamp drive is made with control from the switch of the luminous flux, made in the form of a drum, the axis of the cat The ory is located in the plane of the light flux parallel to the slit diaphragm, which has a pair of through: openings that are offset from each other around the circumference of the drum at an angle of 90 ° and spaced along the axis of the drum. At the same time on the surface of the drum there are several pairs of through holes, evenly distributed around the circumference of the drum. The drawing schematically shows the proposed device. The device for measuring the distribution characteristics of the fibers along the length contains the illuminator -1, lens 2 and collimating lens 3 for obtaining parallel light flux, switch .4 light flux with drive 5, adjustable slit aperture 6, sample 7 with clip 8 mounted on the carriage 9, moving in guides 10, an armature drive consisting of a screw pair 11 and a stepper motor 12, a tamping lens 13, in the focus of which an aperture of the diaphragm 14 is installed, to cut off the scattered component of the luminous flux, emnik 15 and the control unit -16 stepper rivodom. Position 17 designates the course of light rays through the sample, position 18 indicates the course of light rays bypassing the sample, position 19 indicates electric: a photodetector 15 a control unit 16 with a stepper drive a stepping motor 12.

The device works as follows.

The light flux from the illuminator 1 through the lens 2 hits the collimated lens 3, which converts the flow of parallel light rays. The flow of parallel light rays through the switch 4 of the light flow, driven in rotation by the drive 5, is alternately directed to

sample 7 through the slit diaphragm (item 1 7) or bypassing the sample (position 18). In order to enable variable switching of the beam of light rays, the switch 4 of the luminous flux is drum-shaped, the axis of rotation of which is located in the plane of the luminous flux parallel to the slit diaphragm 6. On the drum surface there are a pair of through holes a and 5 displaced along the drum surface relative to each other at an angle of 90 and spaced along the axis of the drum. A portion of the luminous flux 17, which falls on the photodetector 15, passes through the hole, passes through sample 7. That part of the light output 18, which passes to the photo receiver 15, passes the sample through the hole p. 7. Cut out diaphragm 6 from the luminous flux 17 passing through hole Oh, a narrow beam of parallel light rays, pass through the sample. 7, is collected by the focusing lens 13, falls on the photodetector 15 and, more recently, as an electrical signal, into the information processing and display system (not shown in the Drawing.). A light flux 18 collected by a focusing lens 13 is passed through a hole bypassing the sample 7 and also gets on the photodetector 15 and further as an electrical signal. theme of working and displaying information; Dp of calculating the geometric characteristics of the fibers, it is necessary to measure the dependence of the number of fibers in the sample section as a function of the distance from the clamping line (initial position) to the controlled section. For this purpose, the sample 7, placed in the clamp 8, mounted on the carriage 9, is moved by a carriage drive so that the luminous flux intersects all sections of the sample, starting from. clamping lines (starting position).

Each switch of the light beam switch during the working stroke;

the sample (measurement) is converted by the photodetector 15 or in any other way into an electrical signal supplied to the control 16 by a stepper drive. The number of electrical pulses from the control unit 16 to the stepping motor 12 is related to the switching quantity of the switch 4 of the light flux. One switch of the light output switch can correspond to 1, 2, 3, 4, etc. impulses arriving at a stepper motor. The required number of pulses per one. The switch of the light flux switch can be set with a special switch (switch installed on the stepper drive control unit. Since the measurement range (sample movement) corresponds to a strictly specified number of light switch switches, the sample ranges in different 5 positions correspond to the switch 7. The number of switchings of the luminous flux switch during the working stroke is recorded by a special device in the control unit. and a stepper drive. Upon reaching the required number of switches of the light switch, pulsing the control unit with 16 stepper drives for a stepper motor

5 12 is stopped, with the result that the clamp with the specimen is fixed in the uppermost position. To return clamp 8 to its original position, the stepped drive is switched to reverse.

0 Return to the initial position and fixation occur as described above.,

Controlling the light flux from the switch provides greater measurement accuracy by reducing the links in the kinematic chain of the specimen clamp. It eliminates the need to use a reducer, electromagnetic couplings, including the working and reverse travel, devices for exact stopping of the carriage in the same position. It simplifies the device on various measuring ranges, since it eliminates

5 the need for interchangeable restores. All these functions are performed by a stepper drive. In addition, improved accuracy can be achieved for

counting the movement of the clamp with the sample. The stepper drive control can be constructed in such a way that, at the time of photometric measurement of the cross section of the sample (measurement), the latter is in a stationary state, and the sample is moved during:; - the passage of the light flux bypassing the sample. In addition, the proposed luminous flux switch design makes it possible to use an optical system as a bypass luminous flux and to refuse to use optical fibers.

Claims (2)

Invention Formula I. Device for measuring fiber length distribution characteristics, comprising a radiation source, a specimen clamp with a drive, an optical system for forming a light flux, a light flux switch, an adjustable slit diaphragm, an aperture diaphragm, a photodetector mounted along the light flux, and a mechanism fiber parallelization and computational device with recorders, that is, in order to improve the measurement accuracy of fiber length distribution characteristics and simplify the design, The clamping drive is made with DT control of a light beam switch made in the form of a drum whose axis is located in the plane of the light flux parallel to a slit diaphragm having a pair of through holes displaced relative to each other around the drum circumference by the angle of spaced apart drum axis. 2. The device according to claim 1, about tons of l and one such that on the surface of the drum there are several pairs of through holes evenly distributed around the circumference of the drum. Sources of information taken into account in the examination 1. USSR author's certificate No. 513267, cl. G 01 J 1/04, 1974. 2. Exploration on the development of new devices for the rapid determination of the quality of raw cotton, its products and kenaf fibers. Technical Report TsNIIHLROM 24/3979, 1971, topic Number 19 (prototype).