RU2624829C1 - Vibrating field characteristics control method and device for its implementation - Google Patents

Abstract

FIELD: machine engineering.

SUBSTANCE: method involves the installation on the surface of the desktop sensors fixation parameters of vibrating movement of the working body. At the same time produce simultaneous signals fixation with sensors placed on your body, with a mandatory fixing of the measured one directional movement, changing the properties of massoinertsionnye working body by moving along the perpendicular guides prigruza, administers the vibration characteristics of the field. Device for implementing the method includes working member rigidly connected to the vibrator sensors. Along the edges of the desktop set prigruza with the possibility of movement on command from the control unit when the information comes from sensors on the need to change the characteristics of the vibration field.

EFFECT: obtaining reliable information.

2 cl, 10 dwg

Description

The invention relates to the field of measurement, control and management of the dynamic characteristics of vibrating technological machines, which are mechanical oscillatory systems, where granular granular mixtures act as elements of the working medium.

The interaction of the working medium with vibrating surfaces is widely used in the technology of hardening the surfaces of parts (Panovko G.Ya. Dynamics of vibrational technological processes. RHD. M.-Izhevsk. 2006, 158 pp., Kopylov, Yu.R. Dynamics of vibration-hardening processes. Monograph / Yu.R. Kopylov - Voronezh: CPI "Scientific Book", 2011. - 568 p.), For example, when machining long parts, which is typical for structural elements of aircraft and vehicles, the formation of a uniform shape is of particular importance. oh vibration field structure, such effects are achieved organization motion shakers working elements when vibratory motion have a certain homogeneity. A feature of technological processes of vibration hardening is the need to ensure continuous tossing of a granular working medium. A number of solutions are known in the direction of providing the necessary conditions for vibrational interactions.

A known method of research (control) of the characteristics (s) of the vibration field created by the actuator of the vibrating installation, which consists in measuring them (controlling them) using sensors (pathogens), rigidly connected with the working surface of the actuator (Vibrations in technology. Reference. In 6 volumes / Ed. Advice: V.N. Chelomey (previous) - M .: Mashinostroenie, 1981. - T. 5. Measurements and tests. - Edited by M. D. Genkin. 1981. 496 from.). The disadvantage of this method is that it does not allow to investigate and control the characteristics of vibration modes using the beneficial properties of the non-retaining nature of the bonds between the granular mixture and the surface of the working body of the technological machine.

The invention is also known (PFEIFFER X., "Device for determining and / or monitoring at least one process parameter", RU 2338164 C1, G01F 23/296, Pub. 10.11.2008. Bull. No. 31) relating to devices for determining environmental parameters, which is a device for determining and / or monitoring at least one parameter of the process of the medium, with an element capable of performing mechanical vibrations, which in one direction carries out mechanical vibrations and which is fixed to the clamp, with an exciting / receiving element that excites m mechanical vibrations of the element and which element receives mechanical oscillations, and results of adjustment / evaluation unit which controls the mechanical vibrations of the element and which determines and / or monitors the process variable.

The essence of the method used according to this patent is that the invention allows to determine and / or control at least one process parameter. However, the invention does not provide obtaining process parameters of the vibrational interaction of the working granular granular mixture, taking into account non-holding bonds with a uniform and one-dimensional movement of the working body of the technological machine.

In the literature (Vibrations in technology. Handbook in 6 volumes / Ed. Advice: V.N. Chelomei (previous). - M .: Mechanical engineering. 1981. T. 4. Vibration processes and machines / Ed. E. E. Lavendella. 1981. - 504 pp.) Describes the structure of the vibration fields created by the working bodies of the vibration stands with different requirements for the trajectory movements of the points of the working body. It is noted that the structure of the vibration field is not uniform, and therefore the granular medium does not always interact with the implementation of rebounds and subsequent interactions. To control the structure of the vibration field, it is proposed to use traditional means of vibration measuring equipment, which does not take into account the fundamentally important feature, which consists in the need to create continuous tossing modes.

As a prototype taken "Method of research and control the characteristics of the vibration field" [RU 2274843 C1, IPC G01M 7/00. Publ. 04/20/2006. Bull. No. 11]. The essence is to measure or control the characteristics of the vibration field using sensors or exciters, respectively, which are rigidly connected with the working surface of the actuator. It differs in that in order to obtain the exact value of the characteristics (or control of their values) of the vibration field at any point from the given values of the parameters of the vibrational motion and the power consumed for standard actuating organs of vibroinstallations, for example vibroplates, the location of points (vibration nodes) is calculated by calculation, located, depending on the physical properties of the executive body, on its surface or outside this surface, but rigidly connected with it, in which the total value ue any vibration field characteristic parameter (amplitude, frequency, kinematic characteristics of the linear or angular oscillation) is zero, then determine the relative oscillation nodes of vibration characteristics values at predetermined points of the surface of the object; changing the power for the implementation of the oscillations, change the position of the oscillation node and thus the vibrational characteristic at a given point on the surface of the investigated object; Having set the value of the vibrational characteristic at a given point in the field, knowing the position of the vibration unit, the required amount of power is determined.

This method allows to obtain the consumed value of the consumed power. However, the method does not provide obtaining the characteristics of the vibration field formed by the modes that implement the movement of the granular granular mixture in the process of uniform and one-dimensional movement of the working body of the technological machine.

The objective of the invention is to develop principles for constructing forms of implementation, assessing the control and management of the dynamic state of the working bodies of vibrating technological machines, designed to harden the surfaces of large parts in a granular working environment, making continuous vibration-impact interaction with the surface of the parts.

The problem is solved as follows. The method of controlling the characteristics of the vibration field includes the installation of sensors on the surface of the working body, fixing the parameters of the vibrational movement of the working body, characterized in that it simultaneously fixes signals from sensors located on the working body, with the obligatory fixation of the measured movement of one direction, changing the mass inertia of the working body by movements along the perpendicular guides of special movable massive elements (weights), controls characteristics of the vibratory field.

A device for implementing the method of controlling the characteristic of the vibration field includes a working element rigidly connected to the vibrator, sensors, characterized in that along the edges of the desktop installed weights with the ability to move on command from the control unit upon receipt of information from the sensors about the need to change the characteristics of the vibration field.

The signal from the sensors is transmitted to the control unit, recorded, processed and used to adjust the position of the weights.

The invention is illustrated by drawings.

Brief Description of the Drawings

In FIG. 1 shows a schematic diagram of a vibrating stand in the form of a solid body performing vertical vibrations. The working body of the vibrating stand 2 is mounted on the elastic elements 5. Sensors 1 are installed at the corners of the working surface of the vibrating technological machine. Along the side surfaces of the working body of the vibrating machine, guides 4 with weights 3 are mounted with the possibility of displacement using the mechanisms of the translational principle of operation.

In FIG. 2 shows a general outline of a vibration field control circuit. Four sensors 1 are mounted on the surface of the working body of the vibrating stand 2, connected by current leads 6 to the control unit 7. On guides 4, weights 3 are installed, connected by current leads 5 to the control unit 7 and moved by means of translational operating principles along the guides 4.

In FIG. Figure 3 shows a schematic diagram of a rigid body with 6 degrees of freedom, excited by an inertial pathogen in the vertical direction and oscillating on elastic elements k _1, k ₂ , k _3, k ₄ .

In FIG. Figure 4 shows a reduced design scheme of a system with two degrees of freedom of a plane oscillation of a solid with a harmonic input action Q, reflecting the effect of an inertial vibration exciter installed at the corresponding point of the vibration stand.

In FIG. 5 is a structural diagram with selected partial systems interacting through quasielastic bonds.

In FIG. 6 shows a laboratory prototype of a vibrating installation. Sensors 1, 2, 3, 4 are installed on the working body, connected via current leads 5 to the control unit.

In FIG. 7 presents sensors 1, 2, 3, 4 (“A sensor for determining the boundary parameters of the interaction of bodies in vibration systems” [Patent 148250, IPC G01P 15/09, priority 05/05/2014, published: 11/27/2014. Bull. 33]).

In FIG. Figure 8 shows graphs of the results of processing characteristic signals received from 4 sensors during the operation of a laboratory vibrostand. The graphs reflect the time dependence of the voltage at the sensor outputs for four sensors.

In FIG. 9 shows a spectrum of a characteristic signal from sensor 1.

In FIG. 10 shows the normalized graphs 1, 2, 3, 4 of the main harmonics of the signals from the sensors 1, 2, 3, 4, respectively, and the main harmonic 5 of the averaged signal (arithmetic mean value of four signals).

Description of the principles of work

The proposed method for controlling the vibrational state of the technological complex and the device for its implementation consist in the fact that 4 sensors are installed simultaneously on the vibrating stand’s working body, the layout of which takes into account the peculiarities of the working body’s oscillation as a solid body that undergoes complex oscillatory motion during harmonic excitation. The method of assessing the structure of the vibration field is focused on measuring the vertical components of velocities, displacements, and accelerations simultaneously with recording on an appropriate storage medium, which allows one to determine the distribution of the amplitudes of displacements, velocities, and accelerations. It is assumed that the uniformity of the vertical movement of the working body of the vibrating stand is preliminarily provided by the corresponding movement limiters and the ability to adjust by maintaining certain ratios in terms of movement parameters in directions other than vertical.

If the motion is homogeneous, then the amplitudes of the oscillations of the signals at the selected points will have the same sign, and the current amplitudes or phases of the oscillations will slightly differ from the rms or arithmetic mean values. If the fraction of motions of a solid body at different coordinates is overestimated, then the signals will have a significant scatter, which makes it possible to start timely correction of the vibration field.

In FIG. 1 shows a schematic diagram of a vibrating stand in the form of a solid body, performing vertical vibrations, excited by an inertial device (for example, an inertial pathogen). The sensor installation is indicated by 1.

In FIG. 2 shows a general scheme for recording signals from sensors. The measured signal enters the control unit, is processed to calculate the arithmetic mean or root mean square value of the oscillation amplitudes and deviations from the average parameters. Information on the signs of velocities and displacements at selected points is separately displayed, and the phases of harmonic decomposition of signals are determined.

Theoretical basis for the method of monitoring and evaluating the structure of the vibration field (state control)

In FIG. 3 shows a schematic diagram of a rigid body with 6 degrees of freedom, excited by an inertial pathogen in the vertical direction.

The mathematical model of a rigid body oscillation can be represented by a system of differential equations of motion along the coordinates of points. To simplify the initial model, the conditions for decoupling the oscillations under given conditions of vibrational vibrations can be provided by introducing special limiters on certain types of movements, as well as by observing certain relations of symmetry of inertial properties. The introduction of restrictions on movements along the axes OX and OY leads to the fact that the system will oscillate only in the vertical direction.

In FIG. Figure 4 shows the reduced design scheme of a system with two degrees of freedom of a plane oscillation of a solid with a harmonic input action Q, which reflects the effect of an inertial vibration exciter installed at the corresponding point on the vibration stand.

Elements of the design scheme in FIG. 4 is a solid body (working body), resting at points A, B on elastic elements with stiffnesses k ₁ , k _2, respectively. It is assumed that the center of gravity is located at point O, located on the segment A and B.

приложено в точке на расстоянии

от точки О. Система совершает малые колебания относительно положения статического равновесия, силы трения предполагаются малыми. Рассматриваются одновременно две неподвижные системы обобщенных координат относительно положения статического равновесия твердого тела. Обобщенные координаты {у₁,у₂} определяют смещение точек А, В, {у₀,ϕ} - определяют смещение центра тяжести по вертикали и угол поворота.Harmonic power disturbance

applied at a point in the distance

from point O. The system makes small oscillations relative to the position of static equilibrium, the friction forces are assumed to be small. Two fixed systems of generalized coordinates with respect to the position of the static equilibrium of a solid are considered simultaneously. The generalized coordinates {y ₁ , y ₂ } determine the displacement of points A, B, {y ₀ , ϕ} - determine the vertical displacement of the center of gravity and the angle of rotation.

Taking into account the assumptions, the generalized coordinates of two fixed reference systems y ₁ , y ₂ and y ₀ , ϕ are related by the relations:

и

, где

,

,

.

and

where

,

,

.

In accordance with the Lagrange formalism, a system of differential equations is compiled, which, after the Laplace transform, can be transformed into a structural mathematical model. A block diagram with selected partial systems interacting via quasi-elastic bonds is shown in FIG. 5.

The conditions for the uniformity of the vibration field are correlated with the idea that for given external perturbations, the ratio of output signals on partial systems will be equal to unity:

, обеспечивающую однородную структуру вибрационного поля в зависимости от параметров вводимого устройства и приложенной силы:The resolution of equation (1) with respect to p = iω allows us to determine the frequency of the external action

providing a homogeneous structure of the vibration field depending on the parameters of the input device and the applied force:

изображения

и

равны между собой и составляют величину:On frequency

Images

and

are equal to each other and amount to:

существует и не равно нулю, если выполнены условия:Given the analytical features of expression (3), the solution

exists and is not equal to zero if the conditions are met:

точки приложения силы

от центра тяжести с выполнено условие:The frequency of the regime of uniform motion of a rigid body is realized if, for the displacement

force points

from the center of gravity with the condition:

- частоты однородного вибрационного поля. Частота

определяется массоинерционными характеристиками колебательной системы, которые могут быть изменены, в частности, посредством изменения положения центра тяжести (с помощью перемещения пригрузов).Thus, conditions (5) ensure the existence of

- frequency of a uniform vibration field. Frequency

determined by the mass inertia characteristics of the oscillatory system, which can be changed, in particular, by changing the position of the center of gravity (by moving the weights).

To evaluate and control the structure of the vibration field, signals from four sensors installed in the corners of the working body of the vibration technological machine are synchronously recorded, and the average value of the amplitudes of the oscillations of the signals is determined:

A _CP = (A ₁ + A ₂ + A ₃ + A ₄ ) / 4.

With a one-dimensional and uniform oscillation of the working surface, the coincidence of the oscillation amplitudes A ₁ = A ₂ = A ₃ = A ₄ will be performed. If the oscillation amplitudes are not equal, this means the presence of angular vibrations. The magnitude of these angular movements can be adjusted by installing weights on the working body, after which the technological process is implemented in the mode of one-dimensional and uniform oscillation.

The adjusting device is a system of rigid beams with weights located on them. In FIG. 1 and FIG. 2 weights 3 can move along the guides 4, using the mechanism of the translational principle of action (an example is a support of a lathe, moved with a lead screw). The scheme is presented in FIG. 1 is an isometric view.

The vibrostand operation is set up at the beginning of the technological process and can be carried out automatically based on information received from installed sensors 1.

In the framework of the invention, the method is implemented by a device consisting of mass inertia elements 3 (FIG. 1), which can move along the guides 4, parallel to the transverse and longitudinal axes of the working body, at sufficiently large distances from the center of mass of the system in the presence of appropriate limiters, providing the possibility of movement along the vertical axis of the working body of the vibrating machine.

Preliminary assessment of feasibility

As an example of the application of the method of controlling the characteristic of the vibration field and the device for its implementation in vibration systems, the technological vibration process of vibration hardening of the helicopter blade spar by means of a working medium formed by a large number of steel balls based on the theory of the interaction of a material particle with a vibrating surface [Vibrations in technique. Handbook in 6 volumes / Ed. advice: V.N. Chelomei (previous). - M.: Mechanical Engineering. 1981. T. 4. Vibration processes and machines. / Ed. E.E. Lavendell. 1981. - 504 p., P. 13] for the case of a horizontal surface that performs vertical vibrations. The machine is formed by three vibrating sections placed on elastic elements, on which spars of helicopter blades in containers are placed on top, inside of which steel metal balls are filled. Such a technological machine may be able to control the amplitude and frequency of oscillation of the supporting surface of the vibrating sections. Due to the imbalance and wear of the elements of the vibrating machine, the amplitude of the vibration of the points of the vibration field may cease to correspond to acceptable values in particular, and there may be a violation of the uniformity of the vibration field of each section of the vibration stand. For the initial adjustment of the vibration hardening mode, it is necessary to evaluate the uniformity of the vibration field of each of the three sections. Installing sensors on the technological supporting surface of the oscillation and determining deviations of the signals from the four sensors from the average value for different positions of point weights along the guides allows a preliminary assessment of the structure of the vibration field of the technological machine depending on the mass inertia characteristics of the working body of the vibrating stand section and adjustment of the structure of the vibration field. If, at certain positions of the loads, the averaged signal has small deviations from the signals from four sensors, then it is believed that the structure of the vibration field is regulated and a uniform structure of the vibration field of the section of the technological machine is achieved.

The technical applicability of the method of controlling the characteristic of the vibration field and the device for its implementation in vibration systems can be justified by theoretical results and model experiment. When considering a mechanical oscillatory system with an external harmonic force disturbance applied to a certain point of a solid, there are mass-inertial parameters of the system that ensure the uniformity of the vibration field.

Thus, it can be assumed that in the event of a violation of the homogeneous structure of the vibrational field, there exist such mass-inertia parameters of the mechanical vibrational system, upon reaching which the structure of the vibrational field becomes close to homogeneous.

To confirm the possibility of obtaining a technical result, an experimental prototype of a vibration unit is presented and four sensor signals are compared with an average value, which characterizes the heterogeneity of the structure of the vibration field based on the difference in phase shifts of the harmonics of the fundamental frequency.

To register the structure of the vibration field, four sensors 1, 2, 3, 4 (FIG. 6) are rigidly attached to the working surface of the vibration machine.

The signals from the sensors 1, 2, 3, 4 (FIG. 6) through current outputs 5 enter the control unit. In the control unit, the signal is processed and presented in the form of graphs of voltages at the current outputs of the sensors depending on time (FIG. 8) and graphs of the spectral representation (FIG. 9). All stress graphs (FIG. 8) have characteristic surges reflecting the periodic moments of impact of the working medium.

Based on the spectral representation of the signals, the fundamental frequency is determined, which coincides for all four signals. For each signal, the phase of the fundamental harmonic is determined. The resulting harmonics are normalized to 1, 2, 3, 4 (FIG. 10) and compared with the main normalized harmonics of the averaged signal 5.

Thus, based on the difference between the phases of the normalized harmonics and comparison with the phases of the averaged signal, it is concluded that the structure of the vibration field is close to homogeneous.

рад, что свидетельствует о сильной неоднородности вибрационного поля и является основанием для принятия мер по коррекции структуры вибрационного поля.So, in accordance with FIG. 10 the average absolute deviation of the phases of the signals 1, 2, 3, 4 from the phase of the averaged signal 5 exceeds

I am glad that this indicates a strong heterogeneity of the vibration field and is the basis for taking measures to correct the structure of the vibration field.

The usefulness of the method of controlling the characteristic of the vibration field and the device for its implementation in vibration systems lies in the possibility of assessing the heterogeneity of the structure of the vibration field in the tossing-up of bulk materials, and as a result, in the possibility of monitoring, adjusting and regulating the operating modes of technological lines of vibration machines.

Efficiency lies in the greater simplicity, reliability and feasibility of the method for controlling the characteristic of the vibration field and the device for its implementation to identify the heterogeneous structure of the vibration field in the vibration tossing mode at the points of the supporting surface of the vibration machine.

Efficiency is confirmed by theoretical results and practical data obtained during laboratory experiments with prototypes.

Claims (2)

1. The method of controlling the characteristics of the vibration field includes installing sensors on the surface of the desktop, fixing the parameters of the vibrational movement of the working body, characterized in that they simultaneously fix the signals from the sensors located on the working body, with the mandatory fixing of the measured movement of one direction, changing the mass inertia of the working body by moving along perpendicular guiding weights, control the characteristics of the vibration field. 2. A device for implementing the method of controlling the characteristic of the vibration field includes a working body rigidly connected to the vibrator, sensors, characterized in that along the edges of the desktop are installed weights with the ability to move on command from the control unit upon receipt of information from the sensors about the need to change the characteristics of the vibration field .

Images