SU1747186A1 - Device for ultrasonic treatment - Google Patents

Abstract

This invention relates to an ultrasonic treatment. The aim of the invention is to intensify the process. here is a technical note. The device contains a working chamber made in the form of a cylinder 1. Connected to the waveguide 3 by means of two projections 4. forming an angle of 15-60 with the tangent to the cylinder 1 at the junction point. The distance between the protrusions 4 is determined by the arc length according to the average diameter of the cylinder 1 according to the formula H пd / с1 ЗП / Е / р (1-дJa. Where Н is the length of the arc between the projections 4; d is the wall thickness of the cylinder 1: с is the speed of the longitudinal ultrasonic wave in the material of the wall of the cylinder 1; E is the elastic modulus; d is the Punch coefficient, and the height of the projections 4 is 1/4 the length of the arc of the cylinder between the projections with equal flexural rigidity of the wall of cylinder 1 and the projections 4. 2 Il. XI VI 00 Os S-.

Description

Fig 1

The invention relates to an ultrasonic technique, namely to the cleaning of parts, the dispersion of materials, the removal of agnails, can be used in the chemical, engineering and other industries.

Known ultrasonic devices operating using oscillations radial-flexural type. They consist of a working chamber made in the form of a hollow cylinder (tube) and ultrasonic magnetostrictive vibrators,

located along the perimeter of the working chamber, perpendicular to its surface. The cylinder of the working chamber is acoustically tuned to the frequency of the vibrators and, during their operation, is excited, creating radial-bending oscillations of the same frequency. These devices are more promising than the well-known ring converters (type CMC-18; CMC-8). working with radial oscillations, since if in the latter an increase in the size (diameter) of the working chamber is unambiguously associated with a decrease in the frequency of oscillations, then in a device with radial ebb oscillations the diameter of the working chamber can be made of various sizes (on the same oscillation frequency), including those with unlimited large diameters. However, devices with radial-bending vibrations have drawbacks that prevent their widespread use, namely: the complexity of manufacturing technology, since the vibrators can be connected to the working chamber only by hand soldering; non-repairable: when the vibrators are cooled, the outer wall of the working chamber is also washed with water, which leads to an irrational selection of ultrasonic energy supplied to the working chamber.

It is also known an ultrasonic device for treating liquid products, the working chamber of which is excited by an acoustic waveguide connected to it by an output end, and an input end to a source of oscillations by an ultrasonic magnetostrictive transducer. This structure is easy to manufacture.

The disadvantage of it is that it limits the supply of ultrasonic energy from the transducer to the working chamber, since the transfer is carried out through one connection. This is a factor that reduces the intensity of the ultrasound field in the working volume of the chamber. Due to the limited supply of ultrasonic energy, the device is sensitive to changes in load, which leads to instability of the oscillation frequency, the appearance of the frequency of another oscillation mode in the chamber walls.

The purpose of the invention is to intensify

processing by increasing the intensity of the ultrasound field in the working volume of the chamber, increasing the stability of the oscillation frequency during operation while maintaining simple technology

manufacturing.

This goal is achieved by the fact that the device contains a working chamber made in the form of a hollow cylinder, and an acoustic waveguide mounted on

the working chamber is perpendicular to its surface, which, according to the invention, is made with two protrusions located at its output end symmetrically with the axis of the waveguide and connected to the chamber

forming at an angle of 15-60 ° to the surface of the chamber wall, and the distance between the axes of the projections N. measured along the centerline of the cylinder of the working chamber is determined by the formula

H

JL-UE

(sixteen

where d is the wall thickness of the cylinder;

E is the modulus of elasticity; d - Poisson's ratio;

c- speed of the sound wave; p is the density of the material of the cylinder, and the height of the protrusions at the waveguide is defined as H with equal flexural rigidity of the chamber wall and protrusions.

When connecting the protrusions at an angle to the surface of the walls, the best conditions for the excitation of flexural vibrations in the chamber are created, and the attachment of the waveguide to the chamber in two places allows both increasing the amount of transmitted ultrasonic energy and stable oscillations that are maintained in the device during operation. The latter is achieved by the accuracy of the size H, which is deposited between the projections on the average diameter of the cylinder.

Having assumed that the wall of the cylinder is an infinite plate (since there is no

edge effect) of thickness d; use the formula for calculating

I would

 / lu i

-HVTFgo

5 (1-) 2

Cases of transformation in the formula (1). get the expression to determine the value of H lb

H

Sh

It should be noted that the protrusions of the waveguide, connected to the flexural-oscillating wall of the working chamber, also perform bending vibrations, and in order for their response to wall oscillations to be zero, the flexural rigidity of the walls and protrusions must be equal, Flexural wavelength, i.e. N.

FIG. 1 shows a device without top and bottom covers, top view; in fig. 2 - the same, assembled, side view.

The device consists of a hollow cylindrical chamber 1, the internal cavity 2 of which forms a processing zone with a certain working volume, and an acoustic waveguide 3 attached to the chamber walls through protrusions 4, made at its output end, symmetrically with the axis of the waveguide 3. The input end of the waveguide 3 is connected with. transformer 5 elastic oscillations of a magnetostrictive converter 6.

The working volume of the chamber 1 is limited by the upper lid 7, in which there is an opening for loading the workpieces, and the lower lid 8 fixed to the chamber by tightening the connecting rods 9 with thread.

The opening in the upper lid 7 is hermetically sealed with the lid 10. A fitting 11 is located on the lower lid for supplying compressed air to the chamber. The overpressure of the gas after treatment is relieved through valve 12.

The instantaneous amplitude of oscillations of the chamber cylinder walls is shown in FIG. 1 dotted line.

The device works as follows.

Claims (1)

In the working volume 2 of the chamber 1 pre-filled with cleaning solution., Put the parts to be ultrasonic processing. The working chamber is then closed with a lid 10, turning the handle 13 to achieve a tight seal between the lids 8 and 10. After that, through the fitting 11, compressed air is supplied to the chamber and an overpressure is created in the working volume, which has a positive effect on the machining process. exposure to ultrasound. To create radial-bending vibrations in the chamber walls, an ultrasonic generator electric voltage is applied to the transducer b from the power source — an ultrasonic generator (not shown). The longitudinal oscillations arising in this case on the converter 6, through the elastic oscillator 5, the waveguide 3 and the protrusions 4 are transmitted to the working chamber 1 and transformed on its walls into radial-bending. In this case, an intensive sound field is created in the volume of chamber 1 and high-quality processing of parts takes place. At the end of the process, the power source is turned off, the relief valve 12 opens and the overpressure bleeds, then the cover 10 opens by turning the knob 13 and the machined parts are removed from working volume 2 of chamber 1. The process is completed. Apparatus of the Invention Ultrasonic treatment apparatus comprising a working chamber made in the form of a hollow cylinder and a waveguide, the longitudinal axis of which is located in one of the diametrical planes of the cylinder, characterized in that, in order to intensify the process, the hollow cylinder is connected to the waveguide by means of two projections made on the end surface of the waveguide is symmetrical to its axis and forming an angle of 15-60 with tangents to the outer surface of the cylinder at the junction with the protrusions the projections is determined such N - 7G- / E 9 p () 2 where H is the arc length according to the average diameter of the cylinder between the projections; d is the wall thickness of the cylinder; c-velocity1 of the longitudinal ultrasonic wave in the material of the cylinder wall; E is the modulus of elasticity of the material of the wall of the cylinder; d is the density of the material of the wall of the cylinder; p is the Punch coefficient of the material of the cylinder wall, and the height of the protrusions is chosen equal to 1/4 of the arc length according to the average diameter of the cylinder between the projections with equal flexural rigidity of the wall of the cylinder and the projections. xvv V4 vN -h s i fig-t