JPH10282197A - Magnet analyzer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To analyze a unit magnet for occurrence of abnormal vibration or noise at the design stage by analyzing the frequency of a magnetization waveform based on the detection results of a magnetic sensor or a rotary encoder using a frequency analyzing means (computer). SOLUTION: A circular magnetized magnet M is secured to a chuck 11 and turned by means of a motor 12, under control of a computer 18, through a D/A converter 15A and a motor driver 15B. Rotational angle of the output shaft of the motor 12A is detected by a rotary encoder 13 and inputted through a counter 16 to the computer 18. At the same time, flux of the magnet M is detected by a magnetic sensor 14 (e.g. a gaussmeter sensor 14A and a gaussmeter 14B) and inputted through an A/D converter 17 to the computer 18. The computer 18 performs FFT analysis based on the inputted flux and rotational angle to determine the frequency of a magnetization waveform which is then analyzed for occurrence of noise or abnormal vibration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnet analyzer (magnet analyzer) for analyzing a magnetized state of a magnetized magnet used for a motor or the like.

[0002]

2. Description of the Related Art In the current motor industry, there is a demand for miniaturization, high torque, low loss, and low noise. Therefore, a magnetized waveform that reduces cogging torque and torque ripple using a high-energy magnet is required.

[0003] In order to know the magnetization waveform, for example, a grip portion for gripping a rotor having a multipole magnet around it, a rotating portion for rotating the grip portion, and a magnet opposing the multipole magnet are provided. Magnetization inspection machine composed of sensors
15).

[0004]

Since the above-mentioned noise of the motor is generated when the motor is actually rotated (for example, 3,000 RPM), for example, the noise may be generated from a bearing or other mechanism, or may be generated by a magnet. It is difficult to determine whether the cause is the disturbance of the magnetization. In addition, the above-described conventional magnetization inspection machine can observe the magnetization waveform of the magnet at rest, but cannot analyze what causes vibration and noise during use. .

It is an object of the present invention to provide a magnet analyzing apparatus for analyzing the occurrence of abnormal vibration and noise with a single magnet at the stage of designing a finished product incorporating the magnet.

[0006]

In order to solve the above-mentioned problems, a first aspect of the present invention is a magnetic detecting means (14) for detecting a magnetic flux of a magnetized magnet; Position detecting means (13) for detecting a relative position; and frequency analyzing means (1) for performing frequency analysis of a magnetized waveform based on detection results of the magnetic detecting means and the position detecting means.
8).

[0007]

Embodiments of the present invention will be described below in more detail with reference to the drawings. FIG.
Is a block diagram showing an embodiment of a magnet analysis device according to the present invention, and FIG. 2 is a flowchart for explaining the operation. The magnet analyzer 10 includes a chuck 11, a motor 12, a rotary encoder 13, a magnetic sensor 14, and the like. The chuck 11 is a three-jaw scroll-type chuck for fixing the magnetized cylindrical magnet M. The motor 12 is a gear motor for rotating the chuck 11, and is connected to the computer 1 via a D / A converter 15A and a driver 15B.
8 is driven and controlled.

The rotary encoder 13 is for detecting the rotation angle of the output shaft of the motor 12, and outputs its output via a counter 16 to the I / O of a computer 18.
Connected to O port.

The magnetic sensor 14 is a sensor for detecting the amount of magnetic flux of the magnet M. For example, a Gauss meter sensor 14A and a Gauss meter 14B are used. The output of the magnetic sensor 14 is converted into a digital signal by the A / D converter 17 and then converted to a digital signal by the I / O of the computer 18.
Connected to port.

The computer 18 has a program capable of performing FFT processing for performing frequency analysis based on the input magnetic flux amount and rotation angle. This computer 18
Includes a display device 19 such as a CRT, an input device 20 such as a keyboard, and an output device 21 such as a printer or a plotter.
Is connected.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG. First, when this device is started, the computer 18 sets the speed via the driver 15B by setting the voltage to the D / A converter 15A, and drives the motor 12 (S101). Next, the computer 18 inputs the rotation angle from the rotary encoder 13 (S102), and determines whether or not the rotation angle is the measurement angle. If negative, the process returns to S102; if affirmative, the process returns to the next S104. move on. Further, the magnetic flux from the magnetic sensor 14 is input (S104), and the measurement is repeated until the angle reaches 360 ° (S105).

Next, a data cutting process is performed (S1).
06). The data clipping process uses FFT from waveform data.
It is performed to make the number of data necessary for the operation, for example,
FFT operation data 1,0 from 5,400 waveform data
Make 24 pieces.

Here, it is determined whether or not the weighting SW is 1 (S107). If affirmative, a waiting process is performed (S108).
Proceed to S109. As shown in FIG. 7, the weighting process is a process for reducing the skirt-like spread by applying a window function to the FFT calculation data when the frequency display causes a skirt-like spectrum spread. . Then, the computer 18 performs an FFT analysis operation based on the FFT operation data (S1).
09).

Finally, the computer 18 displays the obtained frequency of the magnetized waveform on the display device 19 and outputs the frequency from the output device 21 in accordance with an instruction from the input device 20 (S110).

FIGS. 3 to 6 are diagrams showing output results of the magnet analyzing apparatus according to the present embodiment. FIG. 3 shows the rotation angle and the magnetic flux of the magnet A-1 whose magnetization waveform is slightly distorted. FIG. 4 is a diagram showing the result of FFT analysis based on the data of FIG. 3, and FIG. 5 is a diagram showing the rotation angle and magnetic flux of magnet A-2 whose magnetization waveform is close to a sine curve. FIG. 6 is a diagram showing the result of FFT analysis based on the data of FIG.

When comparing FIGS. 3 and 5 with magnetization waveforms,
Although there is only a slight difference and it is difficult to understand, when FIG. 4 and FIG. 6 are compared, it can be clearly seen that the frequency component exists in the portion B in FIG. When the frequency of the portion B in FIG. 4 is increased, when the motor is used, there is a possibility that the noise of this frequency (including an integer multiple frequency) component becomes large. Conversely, when the noise of the motor is loud, it can be confirmed whether the noise is generated from the magnet.

That is, if the frequency of the noise in question coincides with the frequency of the magnetized waveform of the magnet (including an integer multiple), it is immediately recognized that the magnetized waveform is bad, and this frequency is removed. With a magnetized waveform, noise is reduced. If they do not match, it can be determined to be due to another cause. The same applies to vibration.

(Modifications) Various modifications and changes are possible without being limited to the embodiment described above, and they are also within the equivalent scope of the present invention. For example, magnet M
Has been described in the example of the ring type, but may be in the shape of a rod. In this case, a moving device such as a slider may be used instead of the motor 12, and a linear encoder may be used. Although the calculation of the FFT has been described in the example performed in the computer 18, an FFT analyzer may be connected.

The magnet analyzer has a hamming window,
Brickman House and Rosenfield functions are built-in. Further, it is possible to compare with a sine waveform by calculation, display the amount of magnetic flux at an arbitrary position by using a cursor, and display a cross point angle list by using a vertical cursor.

[0020]

As described above in detail, according to the present invention, the frequency analysis means performs the frequency analysis of the magnetized waveform based on the detection results of the magnetic detection means and the position detection means. At the stage of designing a finished product incorporating a magnet, abnormal vibration,
The generation of noise can be analyzed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a magnet analysis device according to the present invention.

FIG. 2 is a flowchart illustrating an operation of the magnet analyzer according to the embodiment.

FIG. 3 is a diagram showing a relationship between a rotation angle and a magnetic flux of a magnet A-1 whose magnetization waveform is slightly distorted.

FIG. 4 is a diagram showing a result of FFT analysis based on the data of FIG. 3;

FIG. 5 is a diagram showing a relationship between a rotation angle and a magnetic flux of a magnet A-2 whose magnetization waveform is close to a sine curve.

6 is a diagram showing a result of FFT analysis based on the data of FIG.

FIG. 7 is a diagram for explaining a waiting process of the magnet analyzer according to the embodiment;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Magnet analyzer 11 Chuck 12 Motor 13 Rotary encoder 14 Magnetic sensor 14A Gauss meter sensor 14B Gauss meter 15A D / A converter 15B Driver 16 Counter 17 A / D converter 18 Computer 19 Display device 20 Input device 21 Output device

Claims (1)

[Claims] 1. A magnetic detecting means for detecting a magnetic flux of a magnetized magnet, a position detecting means for detecting a relative position between the magnet and the magnetic detecting means, and a detection result of the magnetic detecting means and the position detecting means And a frequency analysis means for performing frequency analysis of the magnetized waveform based on.