JP3059536B2 - Vibration control device for vibration testing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration tester for performing a long-term fatigue test of an elastic test piece such as a spring material, and controls the level and amplitude of an AC signal applied to the vibration tester. Device for

[0002]

2. Description of the Related Art Conventionally, a control device of a vibration testing machine is as follows.
A signal applied to the tester is divided into a plurality of stages by a program, and the frequency, level, and amplitude are changed for each stage.

That is, as shown in FIG. 2, an AC signal having a different frequency, amplitude, and average value is generated at predetermined time intervals, and this AC signal is applied to a tester. Further, a feedback signal for keeping the amplitude constant from a signal from the pickup of the tester is obtained, the feedback signal and the AC signal are input to a multiplier, and a difference between the feedback signal and the AC signal is applied to the tester. , The test machine was controlled to match the input AC signal.

[0004]

In the above-described conventional control apparatus for a test machine, the control is performed by the difference between the signal from the pickup and the input AC signal after the stage is switched. Therefore, it takes time for the input AC signal amplitude to reach a constant value at the time of stage switching, and the applied signal voltage to the test machine overshoots and the test piece vibrates more than the expected value, and accurate testing is performed. There was a problem that could not be done.

Although the average value applied to the tester varies, the conventional tester does not control the average value.

An object of the present invention is to solve the above-mentioned problem, and an object of the present invention is to store a difference between a target set value of an amplitude and an average value in a previous step in each step and a feedback signal. By using the previously stored difference in the next step,
It is an object of the present invention to provide a vibration control device of a vibration tester capable of performing a vibration test at an early stage with a constant amplitude and a constant average value.

[0007]

Vibration control device for a vibration tester of the present invention, in order to solve the problems] intended to St achieve the object described above, the circumferential
Are multiple oscillators oscillating AC signals with different wave numbers?
Then, by sequentially switching the switch every predetermined time,
Select one AC signal, and select the selected single AC signal
The single AC signal among a plurality of different amplitude values.
Multiplying a single amplitude value corresponding to the
In each of the plurality of DC signals having different values,
A single DC signal corresponding to the AC signal of
Vibrates the test piece according to the vibration test signal obtained by adding
A vibration control device for a vibration tester,
The vibration of the test piece detected by the pickup of the testing machine
From the output signal corresponding to the motion, the peak value of the amplitude of the output signal
And an average value of the DC signal component of the output signal.
Amplitude / average value detection circuit, corresponding to the plurality of oscillators
Provided on the test piece according to the vibration test signal
Of the vibration applied and detected by the pickup,
The output signal detected by the amplitude / average value detection circuit;
To the peak value of the signal amplitude and the sequential switching of the switches
Thus, a single oscillating single AC signal selected
Compare with a preset amplitude value corresponding to the oscillator
An amplitude value difference calculator for calculating a difference between amplitude values;
A plurality of oscillator test signals are provided corresponding to the plurality of oscillators.
Applied to the test piece according to the
Of the vibration detected by the amplitude / average value detection circuit.
The average value of the detected DC signal component of the output signal,
Compare with the average value set in advance for the single oscillator.
Comparing the average value difference, calculating an average value difference ,
A plurality provided corresponding to the plurality of oscillators, the single
Calculated by the amplitude value difference calculator corresponding to the oscillator.
The corrected amplitude value for the error obtained by correcting the difference between the amplitude values
As a single amplitude value corresponding to a single AC signal,
Memory corresponding to the amplitude value memory and the plurality of oscillators
A plurality of the average values corresponding to the single oscillator
Correcting the difference between the average values calculated by the difference calculation unit.
Error corrected average value corresponding to the single AC signal
An average value memory for storing as the single DC signal.
It is provided .

[0008]

According to the vibration control apparatus for a vibration tester of the present invention having the above-described structure, the same oscillator among a plurality of oscillators is used.
A single AC signal from the
Is selected the second time or later.
Corresponding to this single AC signal
The error amount stored in the amplitude value memory as a single amplitude value
The corrected amplitude value is multiplied in a multiplier and
The average value as a single DC signal corresponding to one AC signal
The corrected average value for the error stored in memory is added to the adder.
The addition results in a vibration test signal.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG. Reference numeral 1 denotes a vibration tester. When an AC signal as shown in FIG. 2 is input to an input terminal 1a, a signal is generated in accordance with the AC signal.
Vibration test signal is applied to the tester, tester with applying vibration to the test piece, this vibration is outputted from the output 1b is detected by the pickup.

An amplitude / average value detection circuit 2 for detecting an average value of a peak value and a DC level value of an amplitude value in an output signal detected by a pickup of the vibration tester 1;
3 _1, 3 _2, 3 ₃ is an oscillator that generates a different AC signals each frequency.

4 ₁ , 4 ₂ , 4 ₃ are the oscillators 3 ₁ , 3
_2, 3 amplitude value as a target of each frequency than ₃ is a target amplitude value that is amplitude and memory than the switch ₈₂ to be described later are the memory is switched amplitude and mean value detection circuit 2 Amplitude after performing comparison and correcting the error
The target amplitude value calculation unit that calculates the value
5 ) , 5 ₁ , 5 ₂ , 5 ₃ are the target amplitude value calculation sections 4 ₁ ,
4 _2, 4 ₃ the computed amplitude value memory by an amplitude value memory to be output and is switched switch 8 ₃ described later.

6 ₁ , 6 ₂ , 6 ₃ are the oscillators 3 ₁ , 3
_2, 3 the target average the average value of the DC level of the target for each frequency is an average value and memory than the switch 8 ₄ which will be described later The memory is switched amplitude and mean value detection circuit 2 from ₃ Value and compare the error
Target average value calculation unit (average value difference ) that calculates the corrected average value
Corresponding to a partial calculating unit), 7 _1, 7 _2, 7 ₃ and the memory the target average value memory 6 _and 62, 6 average value calculated by _3, and outputs the switched switch 8 ₅ described later It is an average value memory.

Reference numerals 8 ₁ to 8 ₅ denote switches whose contacts can be sequentially switched at predetermined time intervals by a control circuit 9, and 10 denotes an oscillator 3
_1, 3 _2, 3 _3, wherein the amplitude value memory 5 ₁ to the AC signal from, 5 _2, 5 amplitude value of from ₃ a multiplier for multiplying the 1
1 is a signal from the multiplier 10 which is used to store the average value memory 7 ₁ ,
7 _2, 7 is an adder for adding the average value of from _3.

[0014] Next, the operation will be described based on the configuration described above, when the switch 8 _{1-8 5} is switched to the position shown by the control circuit 7, the oscillator 3 ₁ constant frequency, constant amplitude and constant since the output of the f ₁ becomes the AC signal is an average value of the DC level, this signal is applied to multiplier 10 through the switch 8 _1.

[0015] Since the target amplitude value than the amplitude value memory 5 ₁ in the multiplier 10 is applied, an AC signal from the oscillator 3 ₁ and are multiplied in a multiplier 10, further, the AC signal adder is superimposed on the mean value of the target DC level in 11 exchanges in stage t ₁ shown in FIG. 2
A vibration test signal is applied to the input terminal 1a of the tester 1. Then, the testing machine 1 starts to vibrate based on the vibration test signal, and applies vibration to the test piece.

Since the tester 1 cannot follow the vibration test signal and an error occurs in the average value of the amplitude and the DC level, an output including the error is detected by the pickup of the tester 1. Output from the output terminal 1b. From this output, the amplitude / average value detection circuit 2 detects the peak value of the amplitude value and the average value of the DC level values.

[0017] Then, the target amplitude value computing a peak value of the amplitude values than the amplitude-average value detection circuit 2 via the switch 8 ₃
Is input to Part 4 _1, in the target amplitude value calculating unit 4 _1, is compared with an amplitude value set in advance, the amplitude value obtained by correcting an error component is the memory is input to the amplitude value memory 5 _1.

Further, the average value of the DC level from the amplitude and the mean value detection circuit 2 is input to the target average value calculating section _61, in the target average value calculating section ₆₁ is compared with a preset average value , the average value obtained by correcting the error component is the memory is input to the mean value memory 7 _1.

[0019] Then, when the time t ₁ of the first stage has elapsed, the switch 8 _{1-8 5} is switched to the second stage by the control circuit 7, an AC signal from the oscillator 3 ₂ via the switch 8 ₁ At the time t ₂ of the second stage, it is input to the testing machine 1. Therefore, the same operation as described above is performed, and the amplitude value corrected for the error is stored in the amplitude value memory 5.
₂ to be stored, also the average value obtained by correcting the error component is stored in the average value memory 7 _2. Hereinafter, in which it is also stored in the amplitude value memory 5 ₃ and the average value memory 7 ₃ at time t ₃ of the third stage in the same manner.

[0020] The finished vibration test of each step by the operation described above, the amplitude of the modified back to the first step again, the error of than the amplitude value memory 5 ₁ to the multiplier 10
Since the value is input, the oscillator 3
Amplitude value obtained by correcting the error of the alternating current signal from the ₁ are multiplied, and since the average value of the modified DC level than the average value memory ₇₁ is input to the adder 11, from the multiplier 10 was modified AC signal amplitude value is modified
The average value of the dc level is superimposed, the input end 1a of the tester 1
Is input to

Therefore, since the tester 1 is driven by the data corrected in the previous vibration test, the tester 1 operates with the amplitude and the average of the DC level close to the target value, so that an accurate vibration test can be performed. Things. Also, testing machine 1 by the amplitude value memory 5 _2, 5 ₃ and the average value memory 7 _2, 7 modified signal at the output of from ₃ to each step in the same manner vibrates. Hereinafter, the above operation is repeatedly performed for each cycle.

[0022]

As described above, according to the present invention, the error stored in the amplitude value memory at the previous step in each step is described.
Minute corrected amplitude value to a single amplitude corresponding to a single AC signal
Value, and average value
By adding the AC signal the multiplication to the mean value of the DC level that fixes stored in memory, can be performed by the amplitude value and the average value of the target in the vibration test in each step, thus, Naru accurate vibration test Can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a vibration control device of the present invention.

FIG. 2 is a waveform diagram of an AC signal applied to a vibration tester.

[Explanation of symbols]

1 Vibration Tester 2 amplitude and average value detection circuit 3 _1, 3 _2, 3 ₃ oscillator 4 _1, 4 _2, 4 ₃ target amplitude value calculating unit 5 _1, 5 _2, 5 ₃ amplitude value memory 6 _and 62, 6 ₃ Target average value calculation section 7 ₁ , 7 ₂ , 7 ₃ Average value memory 8 ₁ to 8 ₅ Switch 9 Control circuit 10 Multiplier 11 Adder

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01M 7/02 G05D 19/02

Claims (1)

(57) [Claims] An oscillator oscillates AC signals having different frequencies.
Switches from multiple oscillators at predetermined time intervals.
By switching, a single AC signal is selected and the selected
A single AC signal has a different
The single amplitude value corresponding to the single AC signal is input to the multiplier.
Multiple DC signals with different values
A single DC signal corresponding to the single AC signal
According to the vibration test signal obtained by adding in the adder
With a vibration control device of a vibration tester that applies vibration to the test piece.
The test detected by the pickup of the vibration testing machine.
From the output signal corresponding to the vibration of the specimen, the amplitude of the output signal
An amplitude / average value detection circuit for detecting a peak value and an average value of a DC signal component of the output signal; and a plurality of amplitude / average value detection circuits corresponding to the plurality of oscillators;
Applied to the test piece according to the test signal
Circuit for detecting the amplitude and average value of the vibration detected by the
And the peak value of the amplitude of said detected output signal by pre
The single selected by the sequential switching of the switches
By comparing the amplitude value set in advance corresponding to a single said oscillator for oscillating an AC signal, computes the difference between the amplitude value
A plurality of amplitude value difference calculation units provided in correspondence with the plurality of oscillators;
Applied to the test piece according to the test signal
Circuit for detecting the amplitude and average value of the vibration detected by the
Average value of the DC signal component of the output signal detected by
And an average value difference calculator for comparing the average value preset for the single oscillator and calculating the difference between the average values.
A plurality provided corresponding to the plurality of oscillators, the single
Calculated by the amplitude value difference calculator corresponding to the oscillator.
The corrected amplitude value for the error obtained by correcting the difference between the amplitude values
An amplitude value memory for storing as the single amplitude value corresponding to the single AC signal; and a plurality of amplitude value memories corresponding to the plurality of oscillators,
Calculated by the average value difference calculator corresponding to the oscillator
The corrected average value for the error obtained by correcting the difference between the average values
An average value memory for storing the single DC signal corresponding to the single AC signal .