JPS5866826A - Resonance point detector - Google Patents

Abstract

PURPOSE:To permit detection of the resonance frequencies of a rotating device at a high speed and with high accuracy by providing a contactless sensor to the rotating device, stopping the rotation of a movable part by the output signal thereof and converting the excited vibrations to electrical oscillations. CONSTITUTION:A resonance point detector is mounted with a contactless sensor 21 in a rotating device and outputs a stopping signal to a driving part 38 from a positioning part 36 in accordance with the signal outputted from the sensor 21 to stop the rotation of the movable part when the specific position of the movable part comes to the prescribed position of a static part. At this time, the oscillations excited over the entire part of the rotating signal by the signal of the random waveforms outputted to the coil circuit of a DC motor are converted to electric signals by the sensor 21, and resonance frequencies are determined with a frequency analyzer 9, etc. Since the detector is of the system of generating mechanical vibrations by applying the random waveform signals to the coil of the DC motor, resonance frequencies are determined with high accuracy at a high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resonance point detection device for detecting the resonance frequency of a rotating device driven by a DC motor.

Conventionally, as shown in FIG. In order to detect the DC motor (denoted as the frequency), an exciter (4) is installed and the exciter (4) is connected to the oscillator II at (6) via the K amplifier (5), e.g. By applying the five wave signal, vibration is applied to the rotary device (3), and the response vibration of the rotary plate (1) at that time is measured by the rotary plate (1). (7) Convert it to an electrical signal using K, and amplify this electrical signal! Amplify it using (8), and then perform frequency analysis! +9) Input K and detect the frequency that shows the peak value as the resonance frequency.

Since the resonant point detection device is mounted on the rotating plate 11), the resonant frequency is actually lower due to the influence of the weight of the vibration pickup (7). In addition, in the past, not only was it inconvenient to install the vibrator (4) and vibration pickup (7) one by one, but the measured value of the resonant frequency was
2) and the vibration exciter (4) are adversely affected by the manner in which they are coupled, a large-scale rounding device was required to perform correction calculations to remove the influence of 'e'.

The present invention has been made in consideration of the above circumstances.

A non-contact sensor is attached to the rotating device, and the rotating device is stopped based on the electrical signal output from the contact sensor (9 transverse mechanical vibrations excited by the rotating device are converted into electrical signals and An object of the present invention is to provide a resonance point detection device that can automatically and accurately detect the resonance frequency of a resonance point.

Hereinafter, the present invention will be described in detail based on examples with reference to the drawings.

Rotating device (3) which is the object to be measured whose resonance frequency is measured
As shown in Figure 1, it consists of a disc-shaped rotating plate (1) and a DC motor (2) that rotates it.1 The DC motor (2) is coaxial with the rotating plate (1). A rotating shaft (11) rotatably supporting this rotating shaft α, a cylindrical part a coaxially surrounding this bearing part a, and a cylindrical part a connected to the end of this cylindrical part α. Rotating plate (1)
(Fixed part consisting of 0 disc parts facing each other with a certain gap 03 (+! 9, fixed to the outer circumferential surface of the cylindrical part a), 9 stator ends, and the rotating shaft H to the rotating wheel QlT part. It consists of a coaxially connected cylindrical support αn and a rotor 08 fixed to face a stator Oe within this support αn. A magnet I as a sensitive body and a coil (2) as a sensitive body are attached to positions equidistant in the radial direction from the rotation axis inclination of each opposing surface of the plate part (I4), and these magnets (11 and the coil (to) is a non-contact sensor (2)
is formed. From the above coil (to), this coil (
An induced current is output as magnet 0 approaches and separates from (to). Furthermore, the coil (7) is connected via an amplifier to a pass/do pass filter that passes only waves with a frequency of, for example, 150 Hz to 1 KHz, and a low pass filter Q that passes only waves of a frequency of, for example, 50 Hz or less.
4 inputs 1IIK electrically (connected). The output side of the bandpass filter (to) is connected to the input side of the frequency analyzer (9).

This frequency analyzer (9) is connected to the input side of a comparator wire through which an arbitrary reference value can be set via a peak detector (to). This comparison l1 (2e is electrically connected to a display for displaying the results of the test. On the other hand, the above-mentioned low-pass filter The input side of the controller (to) consisting of
The output side of is the above wave number analyzer '9), the above peak detection I
Connected to I@ and the input side of the driver (to). The driver (to) is electrically connected to the step rotary motor C (D).The rotary shaft of this step rotary motor 01 is parallel to the rotary axis α of the DC motor (2). It is set. Then, a friction wheel (to) is connected coaxially with the rotating shaft G3, and this friction wheel (to) is attached to a support αη such that the support body (17+) is interlocked with the rotation of the friction wheel (to). is connected to the outer peripheral surface of.Furthermore,
A random signal generator (b) that generates random waves is electrically connected to the controller (b). This random signal generator 6CI is electrically connected to an amplifier CIK, and the output side of this amplifier (to) is electrically connected to a winding circuit forming an electromagnet of the stator ae via a connector (not shown). The above-mentioned pass filter C24, shutter trigger circuit and controller (to) are used for positioning @
((1) is formed, 9, frequency analyzer + 9), peak detector □□□ and band-pass filter 锡 are the resonant frequency detection part G? ).

Further, the driver (to), the step rotary electric motor Gυ, and the friction wheel (to) constitute a driving section (to).

Next, the operation of the hook swing point detection device according to the one-shot example will be explained.

First, the signal 8A from the controller (to) is sent to the driver MK.
The signal 8B for driving the step rotary motor aD from the driver (to) is applied to the step rotary motor el.
lc'1l)K is applied, and the step rotary electric motor 01) rotates at a constant speed. The support body (iη) rotates via the friction wheel @ along with the rotation of the step rotating electric men.

In addition, the rotary plate (1), which is connected to the support (Iη) through the rotary shaft, also rotates at the same time.The magnet a is connected to the coil (
(to), the coil 4 outputs a relatively monotonous signal SC with a small amplitude as shown in Fig. 3M. However, when the magnet a9 comes directly above the coil (7), the width of the signal SC increases rapidly as shown by arrow N in FIG. This signal SC is amplified by an amplifier and input to a low-pass filter 124. In this low-pass filter 4, a signal SD from which bird frequency components of approximately 50 Hz or higher are removed is input.
is output to the circuit - (see Fig. 2 and Fig. 3).

From this trigger circuit information, a trigger signal SB is output to the controller 4 in response to a preset threshold value of the tweet signal 8D (see Figures 2 and 3), and this trigger signal sT! The controller 4 that inputs J outputs a signal SA' to the driver (to) to stop the rotation, the output of the signal SB from the driver (to) is interrupted, and the rotation of the step rotary motor 00 immediately stops. . Random waveform signal generation ao4 and frequency analysis a(9)K are also output from the above signal 8'. Then, the signals 8' are input, and the 9 random waveform signal generators e4+ output a random waveform signal 8F. This random waveform signal S
F' is amplifier CI! 9, the amplified random waveform signal 8G is applied to the winding circuit of the stator αe, and the DC motor (2) is excited to mechanically capture the random waveform.

As a result, the rotation of rotation 1 [+1] is stopped, and an induced current (to) containing the excited vibration response component of the DC motor (2) due to electromagnetic induction is generated from the coil (to) facing the magnet α' The portion indicated by the arrow R of the signal SC in FIG. 3) is output. The signal SC containing this excitation vibration response component is amplified by an amplifier (2) and then input to a bandpass filter (to). In this bandpass filter @, a signal 8H containing a frequency component of, for example, 150 Hz to 1KHg among the frequency components of the signal SC is outputted to the frequency analysis 5 (9). On the other hand, as mentioned above, the signal SA/ is output from control a-2@ to the frequency analyzer (9),
This signal is KI at the same time as 8 people' input! Wave number analyzer (9)K
We are now preparing for frequency analysis. Therefore, the 9 signal 8H inputted to the frequency analyzer f9) is frequency-analyzed and the signal 8H exhibits a frequency spectrum as shown in FIG.
It is output as peak detection S (2!9) as I. A reference value LT is set in advance in this peak detector (to), and only the resonant frequency fN exceeding the reference value LT is extracted from the signal 8I. Then, a signal 8J indicating this resonant frequency fN is output to the comparator -.This comparison rjIc!eK
In other words, a frequency region fL in which the resonance frequency fN has a constant width,
A comparison operation is performed to determine whether fH (see FIG. 4) K is present.

Here, n is a positive integer and N is the number of rotations of the rotor trout (r,
p, m), and the frequency width Δf is a value that is arbitrarily set depending on the case. If the resonant frequency fN is not within the frequency ranges fL and fHK, it is displayed as "good", and if it is, it is displayed as "bad" on the display (b).

As mentioned above, the resonance point detection device of the present invention is a rotating device (
A non-contact sensor is attached, the movable part is forcibly rotated by the drive part, and when the specific part of the movable part comes to a predetermined position on the fixed part, the positioning part sends the The drive unit outputs a drive stop signal to stop the rotation of the movable part, and at this time, the DC motor winding circuit (the non-contact vibration excited throughout the rotating device by the output random waveform signal) A sensor (converts into a stain signal and analyzes the frequency of this electric signal to determine the resonance frequency), and has the following remarkable effects.

+1) The resonance point detection device of the present invention is a non-contact sensor (it detects more vibrations, so it uses vibration pins as the ninth step in vibration detection).

It is not affected by the weight of the vibration pickup as is the case when using a quag, and unlike the method in which mechanical vibration is externally applied to the rotating device via a vibrator, the winding circuit of the DC motor has a five-wave wave pattern. Since this method generates mechanical imaging by applying a signal, it is not affected by the coupling mode of the vibrator as in the former method. It can be determined with precision.

(2) In actual measurement, all that is required is to bring the friction wheel of the drive unit into contact with the movable part of the rotating device, and to attach and detach the connector for electrical connection between the random signal generator and the winding circuit. Easy to measure.

In addition, in the above embodiment K, the friction wheel (to) is the rotor fI.
Although it is attached so as to be in contact with the outer circumferential surface of the support body αη that supports Although an electric motor is used, any electric motor housing can be used as long as it is a rotating mechanism that can suddenly stop at any position. Similarly, the Schmitt trigger circuit (to) can be replaced with a normal comparison circuit. Furthermore, in the above embodiment, a combination of a magnet and a coil was used as the non-contact sensor, but the sensor is not limited to this, and may be a non-contact sensor consisting of a sensitive body and a sensitive body, such as an eddy current type or a capacitive type. Anything is fine as long as it is.

The Lander waveform signal SP does not necessarily need to be output at the same time as the positioning of the sensitive and sensitive parts of the non-contact sensor, and may be output throughout the entire measurement period.

In addition, various changes can be made without departing from the gist of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a conventional resonance point detection device, and FIG. 2 is a diagram showing the overall configuration of the resonance point detection device of the present invention. Figure 3 is a diagram showing various waveforms generated in the heavy resonance inspection cover shown in Figure 2. *45A is a diagram showing the frequency spectrum analyzed by frequency analysis iS (2) Two-wheel current current m Machine, +14): Circle IE Department, aS:
[Constant S, member; magnet), (21: coil, +21
): Non-contact sensor, (B): Random signal generator, (
To): Positioning section, c37): Resonant frequency detection section, @:
Drive part. Figure 1￥J2 figure

Claims (1)

[Claims] A resonance point detection device characterized by having the following configuration. (a) A drive unit that is connected to the rotating part of the object to be measured and is configured to include a fixed part and a rotating part that is rotatably driven by the DC motor and has a DC motor, and drives the rotating part so that it can be stopped at any position. b) One sensitive body provided on the surface of the rotating part facing the fixed part, and a nine sensitive body attached to the rotating part of the fixed part and facing the nine sensitive bodies every 11 g of the rotating part. A non-contact sensor (not a sensitive body) which is installed at a position and non-contactly detects the approach of the sensitive body (not a sensitive body) and the mechanical vibration of the measured object and outputs it as an electrical signal. C) A signal for stopping the rotation of the rotating part by the drive unit based on an electric signal output from the sensitive body that is electrically connected during sensing and is output from the sensitive body as the sensitive body approaches. A positioning unit that outputs signals to the drive unit and holds the sensitive body and the sensed body facing each other is electrically connected to the DC motor, outputs a random waveform signal to the DC motor, and outputs a random waveform signal to the object to be measured. Random signal generator for generating mechanical vibrations (e) An electric signal corresponding to the mechanical vibration generated in the object to be measured, which is output from the sensing object when the sensing object and the sensing object are held facing each other. a resonant frequency detection section that inputs the electrical signal and detects the resonant frequency of the object to be measured based on this electrical signal.