SU1659542A1 - Sensor of linear density of fibrous product - Google Patents

Abstract

The invention relates to the textile industry. The purpose of the invention is to increase the a-accuracy of the control. A characteristic feature of the ultrasonic linear density sensor of a fiber product is the placement of a reflector on the working part of the receiver with two identical faces forming an angle, the apex of which is facing the radiator. At the same time, the receiver must be removed from the wall1 of the sensor's forming channel for a distance of I −j tg 2 a, where b is the width of the forming channel and a is the angle of inclination of one of the faces at the reflector edge to the surface normal to the axis of symmetry of the radiator. Such an embodiment of the sensor makes it possible to reduce the error of control due to the exclusion of interference effects. 2 of p f-ly, 3 silt

Description

The invention relates to the textile industry.

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

The invention is illustrated in the drawing, where figure 1 shows a general view of the sensor; figure 2 - its cross-section along aa; Fig. 3 shows the reflector of the sensor installed on the working part of the receiver.

A sensor for monitoring the linear density of the fiber product includes a housing 1, in which the forming (product) channel 2 is made, on both sides of which, in the direction perpendicular to its longitudinal axis, the emitter 3 and the receiver 4 of ultrasonic vibrations, the reflector 5 mounted on the working part receiver 4, sleeve 6 with window 7. made of sound-absorbing material and enclosing the reflector 5. Reflector 5 is made with two identical edges, forming an angle facing the top of the radiator 3, and the top of this The eye lies on the axis of symmetry of the emitter 3, the edge of the faces at the top of the angle is parallel to the longitudinal axis of the forming channel 2, and the surfaces of the faces of the reflector 5 facing the emitter 3 are made with concave curves.

Sensor monitoring the linear density of the fibrous product works as follows

Ultrasonic vibrations from the emitter 3 pass through a controlled product, which is driven in the forming channel 2, and get to the receiver 4 which is converted

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This imposes an electrical signal. Since the product being monitored may have a different linear density, the intensity of the oscillations falling on the receiver will not be the same. Consequently, the electrical signal from the receiver 4 will have an equal value. This makes it possible to judge the parameters of the fibrous product being monitored.

Improving the accuracy of control is provided by the reflector 5 and the sleeve 6 made of sound-absorbing material. The ultrasonic waves reflected from the surface of the faces of the reflector 5 fall on the sleeve 6; which is completely absorbed without reflection. Since the distance I from the nearest point on the surface of the reflector 5 to window 7 is set equal to or greater than b / 2tg2 a, the wave reflected from any part of the surface hits the absorbing sleeve 6 and does not fall into the control zone, that is, into the forming channel 2. Therefore, interference phenomena do not occur in it and a traveling wave mode is created. Under these conditions, the amplitude of the sound pressure at the outlet of the layer of fibrous product depends only on the magnitude of the attenuation of ultrasound.

The reflecting surface of the reflector 5 with forming, made concave

view curves

 (B / 2 ± x) 2

41

allows

to provide a traveling wave mode in the control zone with minimum dimensions I and h, where: h is the reflector height 5. The minimum size h provides the minimum size of the wave trace on the receiving surface of the reflector 5, and therefore the maximum uniformity of sensitivity. In addition, the double parabolic surface due to the displacement of the wave trace reduces sensitivity in areas where the surface inclination is maximal (in this case along the axis of the ultrasonic beam). This leads to equalization of the sensor sensitivity over the surface to be sounded, therefore, the distribution uniformity does not matter for it. - neither the fibrous mass in the volume being sounded, which additionally provides an increase in the accuracy of control of the fibrous product.

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Claims (3)

1. The sensor for controlling the linear density of the fibrous product, comprising a housing in which forming A channel, on both sides of which, in the direction perpendicular to its longitudinal axis, is placed an emitter and receiver of ultrasonic vibrations, characterized in that, in order to increase the accuracy of control, it is equipped with a reflector mounted on the working part of the receiver with two identical edges forming the apex facing the angle to the radiator, and the top of this angle lies on the axis symmetry of the radiator, the edge of the faces at the apex of the angle is parallel to the longitudinal axis of the forming channel, and the receiver is removed from the corresponding wall of the forming channel at a distance: I ftg2 ", where b is the width of the forming channel, m; a is the angle of inclination of one of the faces at the edge of the reflector to the surface normal to the axis of symmetry of the radiator. 2. The sensor according to claim 1, characterized in that it is provided with a sound-absorbing material and a sleeve covering the reflector with a window facing formative channel. 3. A sensor according to claim 1, characterized in that the surfaces of the faces of the reflector facing the emitter are concave (b / 2 - + - x V2 curves of the type y = l% -. g 1 I % t / J FIG. 2 i d % H i "7 2 VA No gz