JP2001083032A - Dynamic balance tester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute an accurate balance test in a short time by a method wherein a grade of superiority in balance required for a specimen is input according to a predetermined standard, and a measuring value is determined in accordance with a magnitude of unbalances based on the grade. SOLUTION: When a grade pursuant to superiority in balance based on JIS standards are input into an operation part 13 in correspondence to type or use objects of a specimen W, and a stable width of a measuring value agreeing to the grade is automatically determined. Then, when the specimen W is set to bearings 1a, 1b, and a motor 3 is driven to rotate, respective bearings 1a, 1b are vibrated due to unbalance existing in the specimen W. This vibration is detected by pickups 5a, 5b, and occasionally fetched in the operation part 13 as an unbalance signal. In the operation part 13, at the point of time when a maximum dispersion of a measured value in a prescribed time, for example, in 1 second falls within a predetermined stable width, a rotation of the specimen W is automatically stopped to end a test, and the measured value at that time is displayed as a final measuring value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dynamic balance tester for performing a dynamic balance test on a rotating body such as a motor rotor.

[0002]

2. Description of the Related Art In a dynamic balance tester, generally, a specimen is rotated while both ends of the specimen are supported by bearings, and an unbalance signal generated by the rotation is detected in left and right bearings. The rotation reference pulse is obtained by detecting a mark, a shape characteristic, or the like attached to the surface of the sample, and the magnitude and direction (angle) of the unbalance on both the left and right sides of the specimen are obtained.

By the way, in such a dynamic balance tester, usually, the magnitude of the unbalance (hereinafter, referred to as a measurement result) is a measurement result.
(Referred to simply as a measured value) has a large variation at the beginning of the measurement and gradually becomes stable over time. For this reason, there is a condition that “measured value is stabilized” as a condition for ending the test after starting the test of one specimen. Here, "measured value is stabilized" means a state where the dispersion of the measured value is within a certain range, that is, within a stability range, and in this state, it is regarded that "measured value is stabilized".

[0004] Here, the magnitude of the stability range for considering "measured value is stable" is determined according to the degree of balance required for the specimen. Therefore, the determination of the stability range is as follows. It is determined by the designer of the specimen in consideration of various conditions and the like in the actual use state of the specimen.

[0005]

In the dynamic balance testing machine as described above, if the designer gives an instruction on the stability width which defines the stability condition of the measured value, the test is performed under the stability condition as instructed. It is good, but if there is no such instruction or if it is appropriate, the operator may not be able to determine the conditions for ending the measurement, causing waste that takes longer than necessary for measurement. Alternatively, there has been a problem in that the measurement was terminated in a state where the variation in the measured value exceeded the required balancing accuracy and was large, and an accurate balancing test could not be performed.

The present invention has been made in view of the above circumstances, and requires an unnecessarily long measurement time or an accurate balance even when there is no clear indication of the stability width from the designer of the specimen. The purpose of the present invention is to provide a dynamic balance testing machine that does not cause a problem that a test cannot be performed.

[0007]

In order to achieve the above object, a dynamic balance tester of the present invention detects an unbalance signal obtained by rotating a specimen and a reference position of the specimen. In the dynamic balance tester that measures the magnitude and direction of the unbalance existing in the specimen from the obtained rotation reference pulse, a grade of good balance required for the specimen is input in accordance with a predetermined standard. Means, and a stable width determining means for determining a stable width of the measured value relating to the magnitude of the imbalance based on the input class (claim 1).

Here, in the present invention, in addition to the above configuration, a measured value for judging whether or not the measured value relating to the magnitude of the imbalance falls within the stable width determined by the stable width determining means. Based on the stability determination means and the determination result,
It is possible to employ a configuration including a control means for automatically stopping the measurement operation when the measured value falls within the stable range (claim 2).

The present invention makes use of the fact that the grade of good balance is defined in the standards such as JIS according to the purpose of use of the rotor and the like, and automatically inputs the stability to automatically increase the stability range. To decide.

That is, for example, in a rotor of a motor, a grade of good balance is defined in JIS B0905 according to the purpose of use. The good balance is the balancing accuracy required for the rotor. Therefore, when the measured value is stable within a range that does not exceed the good balance, the unbalance amount as the measured value becomes zero. By performing the alignment correction processing, the rotor should have a good balance that conforms to the JIS standard.

Therefore, according to the present invention, when a grade of good balance required for a specimen is input in accordance with a predetermined standard such as JIS, the measured value is measured in accordance with the balancing accuracy (allowable range) in the grade. The stability width is automatically determined to a range not exceeding the permissible range, for example, １ ／ of the permissible range. In the case of a manual machine, the determined stability width is displayed on a display to notify the operator, or stability determination means for determining whether or not the measured value is within the stability width is provided. By notifying when the value falls within the stability range, or by measuring the value when the measurement value falls within the stability range, based on the stability determination result as in the invention according to claim 2. By providing a control means for automatically stopping the operation, even when there is no instruction regarding the stability width, the operator can satisfy the good balance required for the specimen to be tested without determining the stability width. The following balance test results can be obtained.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the embodiment of the present invention. The specimen W is
The belt 2 is wrapped around the periphery thereof with its both ends supported by the bearings 1 a and 1 b, and is rotated through the belt 2 by driving of the motor 3. Each bearing 1a, 1
b is supported so as to be displaceable with respect to the tester frame via springs 4a and 4b, and when the specimen W is rotated, each of the bearings 1a,
1b vibrates. The vibration of each of these bearings 1a, 1b is
Moving coil pickup (vibration detection sensor)
5a, 5b. Each pickup 5
The outputs of a and 5b are amplified by the amplifiers 11a and 11b as unbalanced signals on the left and right sides of the specimen W, and then digitized by the A / D converters 12a and 12b. It is captured.

Further, a laser sensor 6 is disposed near the surface of the specimen W supported by the bearings 1a and 1b.
The laser sensor 6 detects a mark M attached to the surface of the specimen W. The detection signal is amplified by an amplifier 14 and then formed into a pulse signal of a predetermined shape by a pulse forming circuit 15. The calculation unit 13 takes in the rotation reference pulse of the specimen W.

The arithmetic unit 13 is a digital arithmetic unit mainly composed of a DSP (Digital Signal Processor). In addition to the above-mentioned A / D converters 12a and 12b and the pulse shaping circuit 15, the arithmetic unit 13 also calculates an arithmetic result. A display 16 to be displayed and a key switch 17 for inputting a grade or the like relating to good balance specified in JIS described later are connected to each other. The calculation unit 13 calculates the magnitude of the unbalance on each of the left and right surfaces of the specimen W from the amplitude values of the unbalance signals from the left and right pickups 5a and 5b by a known calculation. From the phase relationship between the balance signal and the rotation reference pulse, the directions (angles) of the unbalance of the left and right surfaces are calculated, and these are displayed on the display 16 as measurement results of the unbalance.

The arithmetic unit 13 automatically determines the stability range of the measured value by inputting a class relating to good balance based on the provisions of JIS B0907, together with the program relating to the above-described unbalance calculation, and A program is written to automatically terminate the test when the measured value falls within the determined stability range. FIG.
4 is a flowchart showing the contents of a program written in FIG.

According to the type of the specimen W to be tested or the purpose of use, the key switch 17 is used to set the JIS B0.
When a grade relating to the goodness of balance based on the rule of 907 is input, the stability range of the measured value that matches the grade is automatically determined and stored. As a specific method of this determination, for example, the grade described in JIS B0907 and the stability range of the measured value required to obtain the balancing accuracy of each grade after the balancing correction are written in the arithmetic unit 13 in advance. Then, a method of reading out the stability range corresponding to the input grade can be adopted.

After the stable width of the measured value is determined in this way, when the specimen W is set on the bearings 1a and 1b and rotated, the arithmetic unit 13 calculates the unbalance signal and the rotation reference pulse as described above. Is used to calculate the magnitude and direction of the unbalance on each of the left and right surfaces of the specimen W. It is determined whether both the measured values of the magnitude of the unbalance on each of the left and right surfaces fall within the stable range. The specific method of that determination is
A method of determining whether or not the maximum variation of the measured values within a specified time, for example, one second, has fallen within a stable range can be given. Then, when the measured values on the left and right surfaces are within the stable range, the rotation of the specimen W is automatically stopped,
The test on the specimen W is completed, and the measured value at that time is displayed as a final measured value.

According to the above-described embodiment of the present invention, the dynamic balance test of the specimen W can be performed simply by inputting the class relating to the goodness of JIS according to the type and the purpose of use of the specimen W. The optimum stability range of the measured value is automatically determined, and the test is automatically terminated when the measured value falls within the stability range. Therefore, even if there is no instruction regarding the stability condition of the measured value of the specimen W, , You can always do an appropriate test.

Here, in the above embodiment, after determining the stable range of the measured value, when the measured value falls within the stable range, the rotation of the specimen W is automatically stopped and the test is terminated. However, when the measured value falls within the stable range, the fact may be notified by some method, or when the measured value is determined to be stable, the value is simply displayed on the display 16. May be.

[0020]

According to the present invention, it is possible to input a grade of good balance in a standard such as JIS based on the type of the test object to be tested and the method of use, and it is suitable for the test of the test object. Since the stability range of the measured value is automatically determined, if there is no indication of the stability condition of the test, the stability range conventionally determined by the operator is generalized according to the type of the specimen, and the Can be easily set.

Further, if the test is automatically terminated when the measured value falls within the automatically determined stability range as in the second aspect of the present invention, the operator can reduce the stability range. It is not necessary to be involved in not only determination but also stability determination of the measured value, and a test with good reproducibility can be performed without an artificial difference in test results.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a flowchart showing the contents of a program written in a calculation unit 13;

[Explanation of symbols]

 1a, 1b Bearing 2 Belt 3 Motor 4a, 4b Spring 5a, 5b Pickup 6 Laser Sensor 11a, 11b Amplifier 12a, 12b A / D Converter 13 Arithmetic Unit 14 Amplifier 15 Pulse Forming Circuit 16 Display 17 Key Switch W Specimen

Claims (2)

[Claims] 1. A magnitude and direction of an unbalance existing in a specimen is measured from an unbalance signal obtained by rotating the specimen and a rotation reference pulse obtained by detecting a reference position of the specimen. Means for inputting a grade of good balance required for the specimen in accordance with a predetermined standard in a dynamic balancing tester, and a stability range of a measured value related to a magnitude of unbalance based on the input grade; A dynamic balance tester comprising: a stability width determining means for determining the stability width. 2. A measurement value stability judging means for judging whether or not a measured value relating to the magnitude of the imbalance falls within the stability width determined by the stable width determining means, and the measurement based on the judgment result. 2. The dynamic balance tester according to claim 1, further comprising a control unit for automatically stopping the measurement operation when the value falls within the stable range.