SU1192372A1 - Device for vibration stabilization of workpiece dimensions - Google Patents

Description

The invention relates to mechanical engineering and can be used to process cast and welded parts to stabilize their size.

A device for vibro-stabilization of the dimensions of parts is known, which contains a vibrator with adjustable drive units for measuring and converting vibration parameters, determining the conditions for an effective impact on a material of a part and then monitoring the results of this influence.

The main disadvantage of this device is the low accuracy of the evaluation of the results of vibration treatment. Oscillation parameters controlled by this device only to a small degree and not always unambiguously characterize those part parameters that determine the subsequent stability of its dimensions. In addition, the use of this device poses great difficulties and requires the creation of special conditions.

The closest to the proposed is a device for reducing residual voltages, which contains a vibrator with an adjustable drive, a control unit, a perturbed frequency sensor, a force sensor, and a displacement sensor that measures the amplitude of oscillations. However, this device also has several disadvantages:

significant changes in the phase angle, on the basis of which the frequency is controlled, are observed only during low-frequency resonances, which sometimes do not arise at all;

the impossibility of detecting and using high-frequency resonances on the harmonic components of the power perturbation;

the inability to use the magnitude of the resonant shear for Monitoring the results of vibroprocessing due to the independence of the phase shift during resonance from the state of the material of the part;

the lack of control over the state of the material of the part when conducting vibrations at the main resonant frequency can result, with sufficient drive power.

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The use of a displacement sensor to control the amplitude does not allow one to single out the most important from the point of view of the effectiveness of the effect of the 5 oscillation frequency, since the value measured by the amplitude sensor characterizes the oscillation of the whole part as a single whole, and not just the material strain amplitude.

, 0 The aim of the invention is to reduce the time of vibro-processing and to improve the quality of stabilization. measures the details by improving the accuracy of determining the optimum vibration frequency 15.

This goal is achieved by the fact that a device containing a vibrator with an adjustable drive, a control unit, a disturbance frequency sensor, a force and a displacement sensor, additionally includes: LFW and HF filters, a measured value accumulator, a frequency meter and two 25 key, while the input of the high-pass bandpass filter is connected to the output of the displacement sensor, and the output is connected to the input of the first key, the control input of which is connected to the output of the sensor of the oscillation frequency of the disturbing force, and the output od this key through a band pass filter connected to the input of frequency meter, which is output through the second switch is connected to a drive input of the direct parameter measured ³⁵ provided with the indicator.

Figure 1 shows a block diagram of the device, figure 2 - diagram of the control unit.

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The device contains a vibrator 1, an adjustable actuator 2 and the associated control unit 3. In addition, it includes a sensor 4 displacement, designed to measure the force acting in the junction between the vibrator 1 and the part, and the sensor 5 of the oscillation frequency of the disturbing force. The output of sensor 4 through a high-pass bandpass filter 6, an electronic key 7 and a low-pass bandpass filter 8 is connected to a frequency meter 9, the output of which is connected via an electronic key 10 to the integrator 11 of the value of the measured parameter, equipped with an indicator 12. ^ The control input of the key 7 is connected to the output sensor 5.

In block 3, a field-effect transistor ТП with high input resistance, С-chains, buttons К is used. and K ^. The time constants (^ £ = 300 s, I _g G = 150, CO = s _h. Closing K _and starts charging of the capacitor C, on the source of the growing capacity and _g, which is supplied to the voltage input of the thyristor drive motor vibrator that causes increasing the frequency of oscillations.At the same time, the second contact connects the meter 9 and the integrator 11. When released, the constant frequency is maintained, and when Kg is closed _{, the} frequency decreases.

The device works as follows. The vibrator 1 is fixed on the part mounted on elastic supports. Then, using control limits located in control unit 3, the command is given to accelerate drive 2 of the vibrator 1, which is carried out with constant slight acceleration. The signal from the displacement sensor, proportional to the disturbing force, is fed to the input of the high-frequency filter 6, with which the high-frequency components corresponding to the harmonics of the power excitation are extracted from the measured signal. The frequency band of the filter 6 below is limited by the frequency of the disturbance of the vibrator, and above it is approximately 10 times higher than this frequency. For example, in the prototype device with a maximum frequency of 200 Hz vibrator filter passband ranged from 200 to 2000 Hz. The output of the filter 6 through the electronic key 7 is connected to the input of the low-pass filter 8 at those moments when the signal from dat92372 is sent to the control input of the key 7

5, which produces one pulse for each oscillation period.

As a result, a sequence of instantaneous values of the high-frequency harmonic component of the disturbing force is fed to the input of the filter 8. A low-frequency envelope of their amplitudes is extracted from a sequence of pulses, while

If the amplitude of the sequence of instantaneous values is constant, the value of the potential at the output of the filter 8 is zero. In an embodiment of the device, the low-pass filter transmission band is from 1 to 20 Hz. The oscillation of the amplitude of the pulses is a consequence of the appearance of high-frequency harmonics that are not multiples of the disturbance frequency of ₂₀ times. The greater the deviation from

the multiplicity, the higher the frequency of oscillation of the amplitude. The signal output from the folder 8 pa limited downwards to avoid interference small in magnitude and po25 steps 9 to the input of frequency meter, with which the determined value of the signal frequency ^ at the filter output 8. Extreme (maximum) meter readings 9 respectively ₃₀ exist conditions most effective impact on the material details.

During the frequency change of the vibrator, the output of the frequency meter 9 through the second electronic key 10 is connected to the input of the integrator 11. The latter is an integrating Yas-chain with a large discharge time of the capacitor, which allows you to accumulate the sum of all frequencies in the entire frequency range of the vibrator. The accumulated value is fixed by the indicator 12 and serves as a characteristic of the dimensional stability of the part.

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Claims (1)

DEVICE FOR VIBRATION DETAIL SIZE STABILIZATION, containing a variable-drive vibrator, a control unit, a disturbing force frequency sensor and a displacement sensor, the control unit, an adjustable-drive vibrator and a displacement sensor connected in series to the output of the adjustable drive; Owing to the fact that, in order to reduce the time of vibro-processing and improve the quality of stabilization of the dimensions of the part by increasing the accuracy. determine the optimum vibration frequencies; it additionally contains high-pass and low-pass filters, an integrator, a frequency meter, two keys and an indicator; the input of the high-pass band filter is connected to the output of the displacement sensor, and the output to the input of the first key, whose control input is connected to the output of the sensor frequency of oscillations of the disturbing force, and the output of this key through a low-pass bandpass filter is connected to the input of a frequency meter, the output of which is connected via the second key to the input of the the grator, whose output is connected to the indicator, and the control input of the second key is connected to the output of the control unit. 1192372 FI.1 one