JPS59230134A - Inertia moment measuring device - Google Patents

Abstract

PURPOSE:To execute a measurement with much higher accuracy than before, and also to improve remarkably the efficiency for measurement by providing a motor for rotating an object to be measured, and a means for measuring a time when this motor reaches a prescribed revolving speed. CONSTITUTION:An object to be measured 4 is placed on a motor 5 so that the rotation of the motor 5 is detected by a frequency generator 6, and its output frequency is converted to voltage by an F/V converter 7. When the motor 5 reaches some revolving speed and the frequency of the frequency generator 6 is F/V-converted, and when a time when its voltage becomes equal to voltage of a reference power source 8 is denoted by tx, in that case, an output of a comparator 9 is changed to ''Lo''. That is to say, no current flows to a constant-torque driving device 11. Therefore, basing on this time, this device measures the inertia moment of the object to be measured, and accordingly, the inertia moment can be measured with much higher accuracy than before.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a moment of inertia measuring device using a motor.

Figure 1 shows a conventional inertia 1/I-moment measuring device.The object 1 to be measured for moment of inertia is a
:3J: Hanging hole with spring 2. Covered? l! l Constant object 1 around the vertical axis, that is, x 1! 1j'' in the θ direction of lI+i9, the direction of rotation of the object 1 is eventually reversed by the action of the elastic force of the spring 2 around the θ direction, and it performs a simple harmonic motion with a period T. Since the elastic force of the spring is constant when J♀ is completely exhausted, the moment of inertia J and the period T are proportional.

That is, Jc, :T (υTherefore, the moment of inertia l-T, which is well known in advance.

is a substance whose period is T. 3 Next, if the period Tx of the unknown object to be measured Jx is determined by 6111, oT0 can be changed from equation (i) and rearranged, and the moment of inertia can be found from this equation c:i12. However, in reality, the period Tx is measured by human eyes, so the illuminance is very poor. Furthermore, in reality, the friction of the spring does not satisfy equation (1). Therefore, there was a problem in that all the springs to be measured and used had to be selected depending on the magnitude of the moment of inertia (rJ).

Purpose of the Invention What is not inventive is - The (111) success or failure of the invention for the purpose of providing a 1. By measuring the time it takes to reach the trench and knowing this time, the total moment of inertia of the object to be measured can be calculated from the relationship between the previously known moment of evanescence and the arrival time.

Description of examples FIG. 2 shows an example of winding the present invention.

Reference numeral 4 denotes an object to be measured, which is placed on the ground of the motor 5.

The rotation of the motor 5 is detected by the full-frequency generator 6, and the frequency for its output is converted into F/V transformer 7 into J and IE. The voltage is determined to be 1. t axis is j'L. The output of the comparator 9 is connected to the input of the flip fluoron 100, and the output is connected to a constant torque drive device 11 for rotating the motor 5 with a constant torque.
It is connected to an external terminal, and a separate Kornit frequency counter 2 is connected to the external terminal (d).

13 is a switch for grounding the input Bi of the flip-flop.

The entire structure and operation of the moment of inertia measuring device @Q of this embodiment constructed as described above will be explained below.

If the moment of inertia of the object to be measured 4 placed on the motor 6 is t, the J1 motor torque is 71 rotations, and the total time is N1, then Noc - t ■ With the proportionality constant f: K /, N = Kl - t ■ In this case, the moment of inertia J can be determined by 6111, assuming that τ and N are completely constant, and t is constant.

K/ So now I = τ and I = x - t GYJ) However, in reality, the inertia associated with the motor 6!・■
Therefore, equation (IV) (d) is transformed as follows.

J Second @tX-Jo (v
) Here ■: 14 of the object to be measured! Moment K:
Constant t: Time taken to reach a constant rotation speed when rotating at a constant torque J: Moment of inertia that causes the motor to rotate at a constant torque Example practice +) + “Explain the operation of the motor/1/measuring device.

When the fixed object 4 is placed on the motor 5, the motor 5 is stationary with the switch 13 turned FF'''.

At that time, the input side of the flip-flop 10 is the ratio axis R'44
1111A, switch (1111B both “Hi”
'' state, the output is low L0'', and a current (d) is flowing through the constant torque drive device 11.Now, when the time at the third quotient is 20 and the switch 13f,p is turned on, the switch of the flip-flop 10 is turned on. The side human power B changes to 4:/L through the switch 13, and the human power B changes to the "L" state.

2 and the output of the flip-flop 10 is in an "H" shape 7.
Instead, the current flows to the p1 constant torque drive device 11 with a current of 2, the motor 6 rotates, and the object to be measured 4 is also rotated with a constant torque.

Then, the motor 6 reaches a certain rotational speed.

That is, the frequency of the frequency generator 6 is F/V converted,
If the time when the voltage becomes equal to the voltage of the reference power source 8 is assumed to be a ringing time, then the output of the comparator 9 changes to °L0°'.

That is, the output of the flip-flop 10 is I=Lo=
I, and no current flows through the constant torque drive device 11. The time t for which the output of the flip-flop 10 is in the "H, '" state. ~tX is read by the frequency counter 12. Figure 3 shows the relationship between the moment of inertia and time measured using a known moment of inertia body.From this figure, J18, which corresponds to tx, is sold.

Or, from the relational expression T = at - J0, without division, - 'observed > 2
It is possible to measure the moment of inertia of object 4.

As described above, according to the present example, put the object to be measured 4 on the motor 5, set the switch to 13 gold, set the frequency 3 to the counter 12, and when the mocro is rotating, take in 8 g of LLIJ. The moment of inertia can be measured accurately and efficiently.

Effects of the Invention In accordance with the present invention, a fixed object is placed on the motor and rotated, and the time required for the motor to reach a predetermined rotational speed is measured,
Since the entire moment of inertia of the object to be measured is measured based on this time, it is possible to measure the moment of inertia with much higher accuracy than before, and it can also be measured with a fixed device regardless of the size of the object to be measured. , it is possible to achieve a significant increase in efficiency compared to conventional methods.

[Brief explanation of the drawing]

FIG. 1 is a principle diagram of a conventional example, FIG. 2 is a block diagram of an example of an actual cannon of the present invention, and FIG. 3 is an explanatory diagram of its operation. 4...Object to be measured, 5...Motor, 6...
・・Frequency emission′ [i,, Iso, 7...F/V
Converter, 8...Reference power supply, 9...Ratio axis 5
．． 10...Furiragurosono, 11...
Constant torque drive device, 12... Counter, 13.
·····switch. Figure 1-Yi Figure 3

Claims (1)

[Claims] A motor that rotates the object to be measured and a motor that rotates the object to be measured.
means for measuring the time it takes for the rotor to reach the rotational speed of 1. To measure f? L-Featured moment of inertia measuring device.