SU726507A1 - Vibrostand control device - Google Patents

Description

The invention relates to vibration devices designed to relieve internal stresses in parts and structures. It can also be used to determine the resonant frequency of structures and components of machines and study their dynamic characteristics.

A device for controlling a vibration bench, comprising a vibration sensor, a master device, a comparison element and a control device [1].

Such a device is intended only to increase the accuracy of reproducing vibrations in frequency by the program, and only com vibration stands.

Closest to the invention for controlling a vibration bench, comprising a vibrator with a DC motor, a vibration sensor, a voltage regulator and a unit for setting the speed of rotation of the electric motor [2].

However, the search for the resonant frequency and the retention of the system in the region of resonant frequencies during the entire cycle of vibration processing of the products is carried out by the operator according to the testimony of measuring instruments, which leads to unproductive and time-consuming energy and complicates the maintenance of the device.

In addition, the execution of the engine and vibrator in one housing narrows the scope of the device and leads to a relatively quick wear of the motor bearings.

The aim of the invention is to increase the reliability of the device.

This goal is achieved by the fact that a flexible shaft, a control unit, and a tachogenerator, adder, and amplifier are connected in series. The second input of the adder is connected to the output of the unit for setting the speed of the electric motor. One output of the control unit is connected to the unit for setting the speed of the electric motor, and the other through a series-connected voltage regulator, an electric motor and a flexible shaft with a vibrator, and the output of the amplifier is connected to the input of the voltage regulator.

The drawing shows a structural diagram of a device for controlling a vibration bench.

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The device comprises a vibrator 1 connected by means of a flexible shaft 2 with a direct current electric motor 3, a tachogenerator 4, a voltage regulator 5, an adder 6, an amplifier 7, a vibration sensor 8, a speed setting unit of an electric motor 9 containing a clock pulse generator 10, a discriminator of the sign of the increment of the signal of the vibration sensor 11 , a reversible binary counter 12, an analog code converter 13, an OR-NOT 14 logic element, a system start trigger 15 and a motor current control unit 16.

The device operates as follows.

In the absence of a vibration sensor signal and in the process of increasing this signal, the discriminator 11 generates a sequence of electrical pulses that are fed to the summing input of the counter 12. In the initial state, the signal at the output of the AND-NOT element 14 prohibits the counting of discriminator pulses, as a result of which the reference voltage at the output of the converter 13 is zero and the system is at rest.

With the arrival of the “Start” signal, the system start trigger 15 is set to a state in which the signal at its output, acting through the NAND 14 element, removes the prohibition of counting the pulses of the discriminator 11. Each discriminator pulse received at the summing input of the counter 12 increases the content, counter per unit. With the arrival of a sequence of pulses, the voltage at the output of the converter 13 increases stepwise, as a result, the rotation speed of the electric motor 3 and the magnitude of the signal, the vibration sensor 8 increase.

The described process continues until the sign of the increment of the signal of the vibration sensor 8 at intervals between two pulses of the discriminator remains positive.

When the region of resonant frequencies passes, the sign of the increment of the vibration sensor signal changes to the opposite. The discriminator fixes the sign of the increment by applying pulses to the other input of the counter 12. The first pulse received at the subtracting input of the counter 12 resets the trigger 15 to its original state, but the system continues to work, since the signal removed from the output is stored at the other input of the AND-NOT 14 element block 16 control the motor current. At the end of the vibration processing, the load current of the motor decreases to the value set by the installation of the current control unit and, in the absence of a signal at the output of the start trigger, the reset signal at the output of the AND-NOT 14 element returns the system to its original state.

The use of a tachogenerator, a summing element, an error signal amplifier, a speed reference unit, and a current control unit can automate the processes of resonant frequency search and vibration processing of products, reduce vibration processing time and power consumption and simplify device maintenance.

In addition, the use of a flexible shaft as a link between the engine and the unbalanced vibrator expands the scope of the device and increases the durability of its components, in particular the electric motor.

Claims (2)

The device comprises a vibrator 1 connected by a flexible shaft 2 to a DC electric motor 3, a tachogenerator 4, a voltage regulator 5, an adder 6, an amplifier 7, a vibration sensor 8, a speed reference unit for an electric motor 9 containing a clock generator 10, an increment sign discriminator signal of vibration sensor 11, reversible binary counter 12, code-analog converter 13, OR-NOT 14 logic element, system start 15 trigger and engine current control unit 16. The device works as follows. In the absence of a vibration sensor signal and in the process of increasing this signal, the discriminator 11 generates a sequence of electrical pulses that go to the summing input of the counter 12. In the initial state, the signal at the output of the AND-14 element prohibits the counting of the discriminator pulses, as a result of which the driving voltage at the output of the converter 13 is zero and the system is at rest. With the arrival of the Start-up Trigger 15 signal, the signal is set to the state in which the signal at its output, acting through the I-NE element 14, removes the prohibition of counting pulses of the discriminator 11. Each discriminator pulse entering the totalizing input of the counter 12 increases the content, counter per unit. With the arrival of the pulse sequence, the voltage at the output of the converter 13 increases in steps, resulting in an increase in the rotation speed of the electric motor 3 and the magnitude of the signal of the vibration sensor 8. The described process continues until the sign of the increment of the signal of the vibration sensor 8 in the intervals between the two pulses of the discriminator remains positive. When the resonant frequency region transitions, the sign of the vibration sensor's signal increment is reversed. The discriminator fixes the increment sign by applying pulses to another input of counter 12. The first pulse received on the subtracting input of counter 12 transfers trigger 15 to its original state, but the system continues to work, since the signal removed by the other input element IE 14 is saved. From the output of block 16, the control current of the engine. At the end of vibration processing, the engine load current is reduced to the value specified by the installation of the current control unit and in the absence of a signal at the start trigger output, the signal "reset at the output of element AND-HE 14 returns the system to its original state. The use of a tachogenerator, summing element, error amplifier, speed setting unit and current control unit allows you to automate the process of finding the resonant frequency and vibration treatment of products, reduce the vibration processing time and power consumption and simplify the maintenance of the device. In addition, the use of a flexible shaft as a motor link with an unbalance vibrator expands the field of application of the device and increases the durability of its components, in particular the electric motor. Apparatus of the device for controlling a vibrostand comprising a vibrator with a direct current electric motor, a vibration sensor, a voltage regulator and a motor speed setting unit, characterized in that in order to increase the efficiency of the device, it contains a flexible shaft, a control unit and a tachogenerator connected in series, an adder and an amplifier, the second adder input being connected to the output of the motor speed setting unit, one output of the control unit is connected to the electric motor speed setting unit I ate, and the other through the series connected regulator voltage, a motor and a flexible shaft - with a vibrator, and an output amplifier connected to the input voltage regulator. Sources of information taken into account in the examination 1. USSR author's certificate number 491932, cl. G 05 D 19/00, 1974. 2. The vibroprocessing device of Martin Engineering Co. (USA) (prototype).