JPH0475453B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a method for detecting an unbalance point in a rotating body such as an armature, and an unbalance point positioning device for a rotating body.

(B) Prior art In general, the measurement of the unbalance of a rotating body as described above involves rotating the rotating body under test and measuring vibrations, centrifugal force, etc. caused by the unbalance, and an unbalance signal obtained from the rotation. From the reference phase signal generated in synchronization with the rotation period of the specimen and corresponding to the reference position of the specimen, the magnitude of the unbalance existing in the specimen and the angle of the existing position with respect to the reference position can be calculated using an electrical method. This is done by deriving it by

Conventionally, in this type of measurement, in order to obtain the above-mentioned reference phase signal, marks are placed on the outer circumferential surface of the specimen in advance, and a detector such as a photocell or proximity switch is used to detect the outer circumference of the specimen during rotation. was scanned to detect the mark, etc., and the detected signal was used as the reference phase signal. According to such conventional methods, not only is it necessary to attach a mark, etc. as a reference to the specimen before measurement, but also the detection of marks, etc. by the detector requires the detection of dirt, scratches, etc. on the surface of the specimen. Otherwise, malfunctions occur constantly due to variations in diameter or changes in ambient temperature, which is a major cause of measurement errors.

(c) Purpose The present invention has been made in view of the above, and provides a method for obtaining a reference phase signal and quickly detecting the position of an unbalance, without attaching a reference mark or the like to a specimen, and a method for determining the position. The purpose of the present invention is to provide a device for positioning.

(D) Configuration The unbalance point detection method of the present invention rotates the specimen and detects the unbalance signal, and also measures the rotation and generates a pulse signal at each predetermined angle that equally divides one circumference of the specimen. Then, a reference phase signal at a predetermined phase of the signal is formed from the detected unbalance signal, and when the specimen rotates at a constant speed, the pulse signal is counted starting from the generation of the reference phase signal, and the counted value is determined in advance. It is characterized in that the position of the specimen relative to a predetermined fixed position at the time when a set predetermined value is reached is detected as an unbalance point.

In addition, the unbalance point positioning device of the present invention includes a sensor that detects an unbalance signal generated by the rotation of the specimen, and removes unnecessary frequency components other than signal components having the same period as the rotation period of the specimen from the sensor output. a reference phase signal generation circuit that takes the filter output as an input signal and generates a pulse-like signal synchronized with the input signal, and a predetermined rotation that measures the rotation of the specimen and equally divides one revolution of the specimen. A rotation angle signal generator that generates a pulse signal for each angle and a reference phase signal generated when the specimen rotates at a constant speed. Using the rotation output as a trigger, the output of the rotation angle signal generator is input and counted, and the counted value is determined in advance. Equipped with a preset counter that generates an output signal when it matches a set preset value, and a stop position that stops the specimen when the output signal of the preset counter is generated, the unbalance point of the specimen is in a fixed position. It is characterized by being configured so that it can be stopped.

(e) Examples Examples of the method and apparatus of the present invention will be described below based on the drawings.

1 and 2 are a front view and a plan view, respectively, showing essential parts of the mechanical structure of an apparatus according to an embodiment of the present invention.

The specimen W is supported by left and right bearings 1a and 1b, and is rotated by a drive belt 3 driven by a pulley 2 of a drive motor. The vibrations generated due to the unbalance of the specimen due to the rotation are absorbed by springs 4 in the left and right bearings 1a and 1b, respectively.
It is detected by vibration pickups 5a, 5b attached via a, 4b. A rotation angle detection roller 6 is disposed around the outer periphery of the specimen W, and is rotated by contact with the specimen W. The rotation is controlled by a rotary encoder 8 via a belt 7.
It is configured to be transmitted to In addition, at a predetermined position on the outer circumference of the specimen W, for example, directly above the specimen W,
A stop device 9 is provided which can instantaneously stop the rotation of the specimen W by driving a notch 9b into the specimen W by the action of a magnet 9a when a command signal is issued.

Next, the circuit configuration of the device according to the embodiment of the present invention described above is as follows.
Description will be made based on the block diagram shown in FIG. 3 and the signal waveform diagram of each part during constant speed rotation of the specimen W shown in FIG.

The output of the vibration pickup 5a (or 5b), that is, the unbalance signal A, is input to the filter 11. The filter 11 passes signal components having a period close to the rotational period of the specimen W, but removes other noises, etc. Therefore, its output is a substantially sinusoidal signal B synchronized with the rotational period of the specimen W. Become. This approximately sinusoidal signal B is transmitted to the shaping circuit 12a and the differentiating circuit 12.
The signal is introduced into the reference phase signal generation circuit 12, which is composed of the reference phase signal generating circuit 12 and the reference phase signal generating circuit 12 composed of The shaping circuit 12a shapes the input substantially sinusoidal signal B into a rectangular wave signal C. At this time, it is desirable to increase the width appropriately at the same time. This rectangular wave signal C is differentiated by a differentiating circuit 12b at the next stage, and outputted as a pulsed reference phase signal D. As is clear from FIG. 4, this reference phase signal D is synchronized with the unbalanced signal A and is generated at the 0° phase of the unbalanced signal A. The reference phase signal D and the unbalanced signal A are known in the art. It is introduced into an unbalance measuring circuit composed of a synchronous rectifier circuit and the like, and is used to measure the magnitude of unbalance. on the other hand,
The rotary encoder 8 receives the rotation of the rotation angle detection roller 6 in contact with the outer periphery of the specimen W through the belt 7, and generates an output pulse signal E of, for example, 360 pulses per rotation of the specimen W. The outer diameter of the contact part of the rotation angle detection roller 6 of the specimen W, the outer diameter of the pulley of the rotary encoder 8, etc. are set so that one pulse of the pulse signal E
corresponds to a rotation angle of 1°.

The timer 13 is turned on at the same time as the drive motor that rotates the specimen W is started, and is activated for a time slightly longer than the time required for the rotation to reach a constant rotation speed range and for the unbalance measurement circuit to complete measurement of the unbalance. The time t ₀ is set in advance, and the drive motor is configured to generate an output signal when the time t ₀ has elapsed after starting the drive motor. That timer 1
The output F of F.3 is introduced into the first flip-flop 14 as a set input. The output H of the first AND gate 15 whose AND inputs are the output G of the first flip-flop 14 which becomes "1" by the set input signal and the reference phase signal D mentioned above is 2 flip-flop 16 as a set input. The output I of the second flip-flop 16 is transmitted together with the output pulse signal E of the rotary encoder 8 to the second AND gate 1.
The output J of the second AND gate 17 is the count input of a preset counter 18 in which preset data is set. The preset counter 18 is the second AND
The count input J from the gate 17 is counted, and when the counted value matches the preset data, an output signal K is generated to operate the stop device 9 and stop the specimen W.

Next, the operation of the embodiment of the present invention will be described. FIG. 5 shows how the unbalance point of the specimen W is determined by the apparatus according to the present invention.
FIG. 4 is a signal waveform diagram of each part when stopping at a position where the stopping device 9 is provided.

After the drive motor is started, the speed of the specimen W is increased to a predetermined constant rotational speed, and the unbalance is measured by the unbalance measuring circuit. After starting the drive motor,
When the time t ₀ has elapsed, the unbalance measurement has already been completed, and the specimen W continues to rotate at a constant speed. After time t ₀ has elapsed, the output F of the timer 13 causes the output G of the first flip-flop 14 to become "1". When the reference phase signal D is generated in this state, the reference phase signal D appears at the output H of the first AND gate 15. This causes the output signal I of the second flip-flop 16 to
becomes "1", so the output J of the second AND gate 17 is output from the rotary encoder 8 from that point onwards.
An output pulse signal E appears and is counted by the preset counter 18. That is, the preset counter 18 starts counting the pulse signal E from the rotary encoder 8 starting from the generation of the reference phase signal D when the specimen W is rotating at a constant speed. When the counted value matches preset data, the preset counter 18 generates an output K to activate the stop device 9 and stop the specimen W. In this embodiment, the preset data of the preset counter 18 is such that the reference phase signal D is generated at a 0° phase of the unbalance signal A, and the position of the stop device 9 is set at 180° with respect to the vibration pickup 5a. be in the position of
The output pulse signal E from the rotary encoder 8 is generated corresponding to a rotation angle of 1° of the specimen W, so that it can be set to 90. That is, the unbalanced point has a phase difference of 90° with respect to the reference phase signal D, and in order to stop the unbalanced point at the location where the stop device 9 is disposed, after the reference phase signal D is generated,
When the specimen W is rotated by 90°, the position where the stop position 9 is disposed coincides with the position of the unbalance point of the specimen W. Note that, if there is a time lag in the operation of the stop device 9 with respect to the output signal K of the preset counter 18, this preset data must be increased or decreased as appropriate in accordance with that time. In addition, in the method of the present invention, in addition to the example in which the specimen W is stopped at a fixed position as in the above embodiment, a marking device may be provided in place of the stopping device 9 to mark the unbalanced point.

(f) Effects As explained above, according to the present invention, there is no need to attach reference marks or the like to the specimen prior to testing, so one step can be reduced compared to the conventional method. Further, unlike the conventional device, a detector for detecting the reference mark is not required, and there is no detector malfunction, which is the main cause of measurement errors in the conventional device, and the reliability of measurement accuracy is improved. Furthermore, since the test specimen can be stopped instantaneously from the test rotation speed, the test time can be shortened.

Furthermore, a non-marking method has already been proposed in which a reference phase signal is obtained by detecting irregularities on the outer periphery of the specimen by scanning the outer periphery of the specimen. It was impossible to measure if there were no noticeable irregularities on the circumference. According to the present invention, even if the specimen is a completely smooth object, it can be measured.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are a front view and a side view, respectively, of essential parts showing the mechanical structure of an embodiment of the present invention. Fig. 3 is a block diagram showing the circuit configuration of the embodiment of the present invention, Fig. 4 is a signal waveform diagram of the main part when the specimen rotates at a constant speed, and Fig. 5 shows the unbalance point of the specimen according to the embodiment of the present invention. FIG. 4 is a signal waveform diagram of each part when the vehicle is stopped at a fixed position. 3... Drive belt, 5a, 5b... Vibration pickup, 6... Rotation angle detection roller, 8... Rotary encoder, 9... Stop device, 11... Filter, 12... Reference phase signal generation circuit, 13...
...Timer, 14, 16...First, second flip-flop, 15,17...First, second flip-flop
AND gate, 18...preset counter.

Claims (1)

[Claims] 1. Detecting an unbalance signal generated by applying rotation to a specimen, and measuring the rotation to generate a pulse signal at each predetermined rotation angle that equally divides one circumference of the specimen. , forming a reference phase signal at a predetermined phase of the signal from the unbalanced signal;
When the specimen rotates at a constant speed, the pulse signal is counted using the generation of the reference phase signal as a starting point, and the position of the specimen with respect to a predetermined fixed position at the time when the counted value reaches a predetermined value is determined as an unbalance point. A method for detecting an unbalance point of a rotating body, the method comprising: detecting an unbalance point in a rotating body; 2. A sensor that detects an unbalance signal generated by applying rotation to the specimen, a filter that removes unnecessary frequency components other than signal components with the same period as the rotation period of the specimen from the sensor output, and the filter output. as an input signal, and a reference phase signal generating circuit that generates a pulse-like signal synchronized with the input signal, and a pulse signal for each predetermined rotation angle that measures the rotation of the specimen and equally divides one revolution of the specimen. The rotation angle signal generator generated and the output of the reference phase signal generator when the specimen rotates at a constant speed are used as triggers to input and count the output of the rotation angle signal generator, and the counted value is preset. It is equipped with a preset counter that generates an output signal when the preset counter matches the value, and a stop device that stops the specimen when the output signal of the preset counter is generated, so that the unbalanced point of the specimen is stopped at a fixed position. An unbalance point positioning device for a rotating body.