JPS6232368A - Detecting device for rotation of high speed rotary body - Google Patents

Abstract

PURPOSE:To perform the correct detection of a rotation automatically by separating the main component of the detecting signal obtd. by detecting the part to be detected with a sensor from the unbalancing component. CONSTITUTION:The detection signal detected by a sensor 3 is amplified by a preamplifier circuit 4 and the main component corresponding to the part to be detected and the unbalancing component by an eccentric rotation are separated by the difference in those frequency components by a separating circuit 5. The separated main component is inputted to a count display circuit 6 to display by counting the number of rotations of a rotary shaft and the digital data thereof are outputted to a control signal output circuit 7 as well. The analog voltage and current proportional to the number of revolutions are outputted and an interlocking signal is outputted by detecting the excess and lack in the number of revolutions as well in the circuit 7. The main component and unbalanced component outputted from the circuit 5 are inputted to an unbalance factor detecting circuit 8 and balance point detecting circuit 9. The voltage corresponding to the ratio of these two components is outputted in the circuit 8 and an interlocking signal is outputted as well when the unbalance factor exceeds as well and in the circuit 9 the phase of the two components are displayed by an angle.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a rotation detection device for a high-speed rotating body, and relates to a rotation detection device applied to detecting the rotation speed of a high-speed rotation shaft such as a rotation shaft of an expansion turbine. It is something.

[Prior art]

For rotating bodies, such as the rotating shaft of an expansion turbine, which are supported by gas bearings or magnetic bearings and rotate at high speed with tens of forces r, p, m, auxiliary means for detecting rotation such as a rotating disk are used. It is impossible to install. Therefore, in such a high-speed rotating shaft, as shown in FIG. 14, the detected part 2 is directly modified into the rotating shaft 1 with a notch, a protrusion, or a reflector that is strictly limited in size, and this is used as a photoelectric sensor. , a magnetoelectric sensor, an electrostatic sensor, and other various sensors 3 for non-contact detection.

However, the rotation signal detected by the above method has a component (
In addition to the main component (hereinafter referred to as the principal component), it also includes a component due to eccentric rotation of the rotating shaft 1 (hereinafter referred to as the unbalanced component), and as shown by the solid line in the figure, if the eccentric rotation is small, the imbalance Since the main component is larger than the main component, the rotation speed can be detected relatively easily by a frequency counter. However, as shown by the broken line in the figure, when the eccentric rotation is large, the unbalanced component is detected to be larger than the main component. In this case, the magnitude of the unbalanced component is not determined by the degree of eccentricity, and the positional relationship between the principal component waveform and the unbalanced component waveform is not determined by the eccentricity position, which causes instability when detecting the rotation speed. This is a contributing factor. For example, if the magnitude and positional relationship between the main component and the unbalanced component are as shown in FIG. 15(e), no matter where the triggering level of the counter is set within the waveform amplitude, the count pulse As shown in the figure, there are 2 pulses per rotation, and the detection result is 2 pulses of the actual rotation speed.
Double. Since the rotational speed cannot be detected using a frequency counter alone, conventionally the rotational signal waveform is constantly monitored using an oscilloscope and visually measured by comparing it with a reference oscillation frequency.

Conventionally, visual measurements have been carried out, which requires considerable skill, has poor accuracy (and lacks responsiveness as continuous measurement is not possible, and data processing is difficult because detection results cannot be obtained as electrical signals). There were problems such as the impossibility of automation and automatic control of rotation.

[Purpose of the invention]

The present invention has been made in order to solve the above-mentioned conventional problems, and has an imbalance with the main component in the detection signal obtained by detecting the detected part provided on the outer surface of a high-speed rotating body with a sensor. The object of the present invention is to provide a rotation detection device that can automatically and accurately detect rotation by separating components.

[Structure of the invention]

The rotation detecting device for a high-speed rotating body according to the present invention includes a sensor that is arranged in a non-contact manner on the side of the high-speed rotating body to detect a detected part provided on the outer surface of the high-speed rotating body, and an output signal of the sensor. a separation circuit that separates the main component corresponding to the detected part from the unbalance component caused by unbalance during rotation of the high-speed rotating body based on the difference in their frequency components, and the main component of the output signal per reference time. The main component corresponding to the detected part in the output signal from the sensor and the unbalanced component due to eccentric rotation are divided into frequency components. The main component is separated in a separation circuit by paying attention to the difference, and as a result, even if the high-speed rotating body rotates eccentrically, its rotational speed can be accurately detected.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on FIGS. 1 to 13. First, the overall configuration will be explained with reference to FIG. 1. The detection signal detected by the sensor 3 is amplified by the preamplifier circuit 4, and the separation circuit 5 separates the main component corresponding to the detected part 2 and the unbalanced component due to eccentric rotation. are separated by differences in their frequency components. The separated principal components are input to a counting display circuit 6, which counts and displays the number of revolutions of the rotating shaft 1, and transmits the digital data to a control signal output circuit 7.
Output to. The control signal output circuit 7 outputs an analog voltage and current proportional to the number of rotations, and also detects an excess or shortage of the number of rotations and outputs an ink clock signal.

Further, the main component and unbalanced component output from the separation circuit 5 are input to an unbalance rate detection circuit 8 and a balance point detection circuit 9. The unbalance rate detection circuit 8 outputs a voltage corresponding to the ratio of these two components and outputs an ink clock signal when the unbalance rate exceeds the ratio, and the balance point detection circuit 9 displays the phase of the two components as an angle. It is configured.

The details of the separation circuit 5 will be explained with reference to FIG. 2. The output signal of the preamplifier circuit 4 is filtered through a high-pass filter 11 (hereinafter referred to as HPF in the figure) and a low-pass filter with variable cut-off frequency and well-matched characteristics. 12 (hereinafter referred to as LPF in the figure), and these high-pass filters 11 and low-pass filters 12 have cutoff frequencies (hereinafter sometimes referred to as ro) that can be varied by input signals of different systems. It is composed of These high pass filter 11 and low pass filter 1
2 output signals are the first and second signals with well-matched characteristics, respectively.
The output signals from these AC/DC converting circuits are input to the high pass filter 11.
and a first differential amplifier 15 which outputs a cutoff frequency converted signal of the low-pass filter 12. The output signals of the high-pass filter 11 and the low-pass filter 12 are input to a second differential amplifier 16 which calculates the difference between these two signals and outputs the main component. Furthermore, a subtracter 17 is provided to subtract a correction value from the input signal input from the high-pass filter 11 to the first differential amplifier 15.

Explaining the function of this separation circuit 5, this basically means that the unbalanced component detected by the eccentric rotation of the rotating body in the output signal of the sensor 3 becomes a sine wave according to the rotational angular velocity. , since the main component caused by the detected part has a pulse waveform with a time width of a fraction of a fraction to a few tenths of a fraction (see Figure 15), the frequency components are different between the two, and the frequency of both is based on the rotation axis. This is based on the fact that the frequency ratio shows a substantially constant value regardless of the rotation speed.

When the cut-off frequency conversion signal outputted from the first differential amplifier 15 is a positive voltage signal, the cut-off frequency r0 is set to the high frequency side, and when the cut-off frequency conversion signal output from the first differential amplifier 15 is a negative voltage signal, the cut-off frequency r0 is set to the high frequency side. If f0 is configured to move toward the lower frequency side, the cutoff frequency f0 will follow the frequency of the output signal of the sensor 3. This will be explained with reference to FIG. 3. Both filters 1
1.12 frequency-amplitude characteristics are shown, the characteristics of the high-pass filter 11 are shown by a large solid line, and the characteristics of the low-pass filter 12 are shown by a solid line. Now, it is assumed that the cutoff frequency f0 is located at a point O where the output signal of the first differential amplifier 15 is zero, that is, the amplitudes of both filter characteristics are equal. Here, if the rotational speed of the rotating body suddenly increases and the frequency of the output signal of the sensor 3 suddenly increases to fX, the high-pass filter 11 outputs the amplitude value at point a, and the low-pass filter 12 outputs the amplitude value at point b. The amplitude value of the point is output, and as a result, the cutoff frequency conversion signal of the first differential amplifier 15 is outputted as a positive voltage signal corresponding to the difference between the two amplitude values, and the cutoff frequency moves to the high frequency side. Then, the f0 point becomes equal to "X.

Conversely, when the rotational speed of the rotating body suddenly drops to fx', the outputs of both filters become a' and b', and a negative voltage signal corresponding to the difference between them is generated as a cutoff frequency conversion signal. The cutoff frequency r0 is fx'
Move to match. In this way, the cutoff frequency f0 follows the frequency of the detection signal from the sensor 3, which corresponds to the rotational speed of the rotating body.

Now, it is assumed that the cutoff frequency f0 controlled as described above is at the position shown in FIG. Assuming that the frequency of the main component is fs, the output signal of each filter will be as shown in FIG. 5(a). That is, 1, a low pass filter 12 for the input signal.
The output signal of the high-pass filter 11 has a waveform in which the amplitude of the main component is attenuated, and the output signal of the high-pass filter 11 has a waveform in which the amplitude of the unbalanced component is attenuated. Here, a subtracter 17 applies a correction voltage to the output signal from the first AC/DC conversion circuit 13 so that the amplitude of the unbalanced component of the output signal of the high-pass filter 11 becomes equal to the amplitude of the output signal of the low-pass filter 12. Adjust to. In other words, by this correction, the cutoff frequency in FIG.
), the output signal of the low-pass filter 12 has a waveform containing both the main component and the unbalanced component, and the output signal of the high-pass filter 11 has a waveform containing both the main component and the unbalanced component because the amplitude of the main component is further attenuated. . In order to ensure this separation, the cutoff characteristics of both filters 11 and 12 are important.If the frequency ratio between the main component and the unbalanced component is large, a filter with a gentle cutoff characteristic may be used, but if the frequency ratio is small, then requires a filter with steep cutoff characteristics.

The output signals of the high-pass filter 11 and the low-pass filter 12 thus obtained are respectively input to the second differential amplifier 16, and as shown in FIG. The main component is output, and the output signal of the low-pass filter 12 is output as an unbalanced component, so that the main component and the unbalanced component are separated and output. FIG. 7 and FIG. 8 show the results of an example in which the main component and the unbalanced component were separated during unbalanced rotation and balanced rotation.

The number display circuit 6, which counts and displays the number of revolutions using the principal components obtained in this way as an input signal, is configured as shown in FIG. 9.The principal components are input to a comparison circuit 18. In the circuit 18, the value inputted from the threshold setting circuit 19 and the principal component are compared, and as shown in FIG.
A 9-pulse signal in which a pulse signal is output every time the main component exceeds the threshold value is input to the pulse count circuit 20,
The reference time generation circuit 21 counts the number of pulse signals for each reference time set, and the count +-i is outputted to the outside and the display circuit 22 displays the display circuit 22. 5.i23
will be displayed. The reference time is usually set when the rotational speed is r, p, a.
+, set to be displayed.

As shown in FIG. 11, the unbalance rate detection circuit 8 includes first and second peak value detection circuits 2 with well-equalized characteristics.
The signals of the main component and the unbalanced component are inputted to 4 and 25, respectively, and the peak value of each component is inputted to the division circuit 26, where the calculation of "unbalanced component/principal component" is performed, and the result is converted into a voltage value. Output. In this way, by fixing the degree of unbalance by the ratio of the unbalanced component to the principal component, it is possible to offset changes in characteristics such as sensitivity or linearity of the detection system including the sensor 3. This can prevent the results from becoming unstable. Further, the unbalance rate obtained in this way is compared with the excess rate that may cause damage to the rotating body, which is preset in the excess rate setting circuit 27, and the unbalance rate is determined as this set value. The ink clock signal is configured to output an ink clock signal to stop the rotation when the rotation exceeds the ink clock.

Furthermore, the balance point is detected based on the following method. Now, for example, the main component and unbalanced component output from the separation circuit 5 have waveforms as shown in FIG. Then, the rotation axis 1 is 270° in the rotation direction from the detected part 2.
It can be seen that the sensor rotates eccentrically so that it approaches the sensor 3 at a position (90 degrees in the counter-rotational direction). Here, if the time from a to b in Figure 12, that is, the time for one cycle (360°) is X, and the time from a to c is Y, then the position (angle) of the 0 point is
can be expressed as 360·Y/X. In other words, the 0 point here is 360.3/'4-270.

The balance point detection circuit 9 performs such calculations.
is constructed as shown in FIG. The X-day 1-303 corresponding to the main component signal and the Y-day 1-30b corresponding to the unbalanced component signal are opened and closed by the gate control signal generation circuit 29 to which the main component and the unbalanced component are input. and a pulse signal from the reference pulse generation circuit 31 is input to these gates, and at point a in FIG.
The Y gate 30b is closed at the 0 point in FIG. , after the count data of the X counter 32a is established, the arithmetic circuit 35 performs the above calculation, and the result is displayed on the display circuit 36.

〔Effect of the invention〕

According to the rotation detection device for a high-speed rotating body according to the present invention, as described above, there is a sensor provided on the outer surface of the high-speed rotating body to detect the detected part, and a main body corresponding to the detected part based on the output signal of this sensor. and an unbalance component caused by unbalance during rotation of the high-speed rotating body based on the difference in their frequency components; Since it is equipped with a counting circuit that calculates the number of rotations of Based on this fact, the main components can be separated using a separation circuit. As a result, even if a high-speed rotating body rotates eccentrically, its rotation speed can be accurately detected, and the rotation can be automatically detected as an electrical signal, making data processing and automatic control of rotation possible. play.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the overall configuration of an embodiment of the present invention, FIG. 2 is a block diagram of a separation circuit, FIGS. 3, 4, 5(a), 5(b) and 6. The figures are explanatory diagrams of the operation of the separation circuit, Figs. 7(a), (b), and (c) and Fig. 8(a).
Nb) (c) is a waveform diagram showing the result of separation processing for an actual example, FIG. 9 is a block diagram of the counting display circuit, FIG. 10 is a diagram explaining the same operation, FIG. 11 is a block diagram of the imbalance rate detection circuit, 12(a) and 12(b) are explanatory diagrams of the balance point detection method, FIG. 13 is the same block diagram, FIG. 14 is an explanatory diagram of the rotation detection state, and FIGS. 15(a), 15(b), and 15. (c) is an explanatory diagram of the same effect. 1 is a rotating shaft, 2 is a detected part, 3 is a sensor, 5 is a separation circuit, 6 is a count display circuit, 11 is a variable cut-off frequency type high-pass filter, 12 is a variable cut-off frequency type low-pass filter, 13 is a first 14 is a second AC/DC converter circuit, 15 is a first differential amplifier, 16 is a second differential amplifier, and 17 is a subtracter. 511I Figure 6 Figure 7

Claims (2)

[Claims] 1. A sensor is placed on the side of the high-speed rotating body in a non-contact manner to detect the detected part provided on the outer surface of the high-speed rotating body, and from the output signal of this sensor, the main component corresponding to the detected part and the main component of the high-speed rotating body are detected. a separation circuit that separates unbalanced components caused by unbalance during rotation based on differences in their frequency components; and a separation circuit that calculates the rotational speed of the high-speed rotating body by counting the main component of the output signal per reference time. A rotation detection device for a high-speed rotating body, characterized by comprising a counting circuit. 2. The separation circuit includes a high-pass filter and a low-pass filter of variable cutoff frequency type, and a first circuit that receives the output signals of these filters via an AC/DC conversion circuit and outputs a cutoff frequency converted signal to both filters.
and a second differential amplifier that subtracts the output signal of the low-pass filter from the output signal of the high-pass filter and outputs the main component. Rotation detection device.