JPH0746071B2 - Balance tester - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a balance tester that calculates an unbalance vector from the output of a pickup and compensates for an error in a vector calculation unit or the like.

2. Description of the Related Art In the case of a balance test, even if a test body in which only a very small imbalance remains is measured, an imbalance of a larger value than the imbalance remaining in the test cycle is displayed on the display unit. Since the imbalance shown on the display portion is caused by an error in the measurement system, the error caused in the measurement system is removed by a method called eccentricity compensation.

Specifically, when mounting the test piece on the mounting jig, it should be mounted at two or more mounting angles and the eccentricity should be electrically compensated from the unbalance vector corresponding to each mounting angle, or the mounting jig should be compensated. A method of adding a weight for use was adopted.

Problems to be solved by the invention The error of the measurement system is that when the test piece is mounted on the mounting jig,
There are two main causes: a mechanical error that occurs when the center of the test piece and the center of the mounting jig do not match, and an electrical error that occurs due to the block that calculates the unbalance vector from the output of the pickup. Has become.

Therefore, when performing eccentricity compensation, it is necessary to compensate for these two types of errors at the same time, and a long time and effort by a skilled engineer is indispensable for the compensation work.

The present invention was conceived in order to eliminate the above-mentioned difficulty of eccentricity compensation, and an object thereof is to compensate an electrical error generated in a block for calculating and outputting an unbalance vector independently from a mechanical error. The purpose is to provide a balance tester that can be used.

Means for Solving the Problems In order to achieve the above object, the balance testing machine of the present invention has a switching unit that outputs one of two kinds of signals, a signal from a pickup or a signal of 0V, and an output of this switching unit. A vector operation unit that calculates and outputs an unbalance vector from the output unit, an error vector storage unit that stores the unbalance vector output from the vector operation unit as an unbalance vector indicating an error when the switching unit outputs a 0 V signal, and at least the switching unit When the signal from the pickup is output, the unbalance vector subtraction unit indicating the error stored in the error vector storage unit and the output of the vector subtraction unit are displayed from the unbalance vector output by the vector calculation unit. And a display unit.

Operation Theoretically, when the mechanical error is 0, the output of the pickup is 0V. That is, by outputting a 0V signal from the switching unit, a state in which the mechanical error is 0 is set for the electrical measurement system including the vector calculation unit. At this time, an unbalance vector is output from the vector calculation unit, and this unbalance vector is an unbalance vector indicating an error caused by the electrical measurement system. The unbalance vector indicating this error is stored in the error vector storage unit. When the signal from the pickup is output to the vector operation unit, subtracting the unbalance vector indicating the error stored in the error vector storage unit from the unbalance vector output by the vector operation unit is an error that occurs in the electrical system. Is offset by an unbalanced vector indicating an error. The unbalanced vector in which this error is canceled appears in the output of the vector subtraction unit and is displayed on the display unit.

Embodiment FIG. 1 is a block diagram showing an electrical configuration of a dynamic balance testing machine showing an embodiment of the present invention.

In the figure, when the test body 11 is rotated by a driving unit (not shown), unbalanced vibration occurs at both ends of the main shaft 111, and this vibration is converted into an electric signal by a pickup 12 that detects displacement of a bearing that supports the main shaft. To be done. Since the processing unit that processes the signal from the pickup 12 has the same configuration for each pickup 12, only the configuration of the right pickup 12 in the drawing is shown and described, and the left pickup is shown and described. Is omitted.

The signal from the pickup 12 is guided to the input a of the switching unit 13, and the input b is connected to the ground indicating a 0V signal. The signal from the pickup 12 or the signal of 0V guided to the input a is output from the switching unit 13 and is guided to the input signal preprocessing unit 14 when the input a or the input b is selected. The input signal pre-processing unit 14 is mainly composed of a band pass filter that passes only a frequency component equal to the number of revolutions of the test body 11 among the components included in the signal from the pickup 12 and removes an extra component. By removing it, we are improving the measurement accuracy and expanding the dynamic range.

Here, the signal from the pickup 12 from which the noise component has been removed as described above is guided to the vector calculation unit 15. Then, the vector calculation unit 15 calculates an unbalance vector corresponding to the guided signal, and the unbalance vector is a signal 151 indicating an X direction component and a signal 15 indicating a Y direction component.
Output as 1Y, and X subtraction unit 171X, Y of the vector subtraction unit 17
It is sent to each addition input of the subtraction unit 171Y and is also sent to the error vector storage unit 16.

The signals 161X and 161Y, which are output from the error vector storage unit 16 and represent the unbalance vector indicating an error, are introduced to the subtraction inputs of the X subtraction unit 171X and the Y subtraction unit 171Y, respectively, and these two subtraction units 171X and The output of 171Y is connected to the display unit 18.

Further, a signal for controlling the operation of the switching unit 13 and a signal indicating the timing when the error vector storage unit 16 stores the imbalance vector are sent from the control unit 19 to each.

The operation of the embodiment of the present invention will be described below.

Prior to the balance test of the test body 11, a control signal is sent from the control unit 19 to the switching unit 13 so as to send the signal of the input b. That is, a signal indicating 0V is guided to the input signal preprocessing unit 14. Then, the signal indicating 0V reaches the next vector calculation unit 15.

The vector calculation unit 15 regards the input signal as a sine wave, sets the reference position to 0 degree, and calculates the phase and wave height of this input sine wave, and outputs the result to the signals 151X and Y directions indicating the X direction component. It is a block that outputs an imbalance vector in the form of two outputs of a signal 151Y indicating a component. In this case, since the signal indicating 0 V is input, the unbalance vector as the output should be 0 vector, but the error due to the operation of the input signal preprocessing unit 14 and the vector operation unit 15 causes Therefore, the unbalance vector represented by the two outputs 151X and 151Y becomes a vector having a value. This vector is an unbalanced vector indicating an error in the measuring section (input signal preprocessing section 14 and vector calculation section 15) of the electric system, and is stored in the error vector storage section 16 in accordance with the signal from the control section 19.

The unbalance vector indicating the error thus stored in the error vector storage unit 16 is output from the two outputs.
It is sent to 161X and 161Y, and keeps the same value thereafter.
Therefore, the same value is input to each of the addition input and the subtraction input of the X subtraction unit 171X and the Y subtraction unit 171Y.
The subtraction output becomes 0. That is, a value obtained by canceling the error caused by the electric system appears in the output of the vector subtraction unit 17, and is guided to the display unit 18.

The compensation of the error generated in the electric system is completed by the above operation, and the switching unit 13 sends the signal from the pickup 12 guided to the input a to the input signal preprocessing unit 14 by the signal from the control unit 19. Then, this signal is output to the outputs 151X and 151Y of the vector calculation unit 15 as an unbalanced vector containing an error in the electrical system. Next, the vector subtraction unit 17 creates an unbalanced vector in which the error in the electrical system has been canceled out, and is guided to the display unit 18 and displayed.

The present invention is not limited to the above-mentioned embodiments, but can be applied to a balance testing machine for measuring static imbalance.

Further, the operation of the switching unit 13 and the error vector storage unit 16 has been described as a configuration that is automatically operated by a signal from the control unit 19, but a configuration of manual operation, for example, a configuration of being operated by a push button switch, etc. Is possible.

Further, the input signal preprocessing unit 14 has been described in the case of a bandpass filter which is analog processing.
It is possible to provide a conversion unit and perform an FFT process to remove excess frequency components, and in this case, the vector operation unit 15 adopts a digital operation unit.

EFFECTS OF THE INVENTION The balance tester of the present invention stores a vector output when an input signal of an electric system for calculating an unbalance vector is 0 V, stores it as an unbalance vector indicating an error, and operates on a signal from a pickup. Since the unbalance vector indicating this error is subtracted from the unbalance vector obtained by applying the error, there is no error in the electrical system and it is sufficient to deal with only the error in the mechanical system. This has the effect of facilitating compensation work.

[Brief description of drawings]

FIG. 1 is a block diagram showing an electrical configuration of a dynamic balance testing machine showing an embodiment of the present invention. 12 …… Pickup, 13 …… Switching section, 15 …… Vector operation section, 16 …… Error vector storage section, 17 …… Vector subtraction section, 18 …… Display section.

Claims (1)

[Claims] 1. A switching unit that outputs one of two kinds of signals, a signal from a pickup or a signal of 0V, a vector calculation unit that calculates and outputs an unbalance vector from the output of the switching unit, and the switching unit has 0V. An error vector storage unit that stores the unbalance vector output from the vector operation unit as an unbalance vector indicating an error when outputting the signal of, and the vector operation unit at least when the switching unit outputs the signal from the pickup. From the unbalance vector output by the subtraction unit for the unbalance vector indicating the error stored in the error vector storage unit, and a display unit for displaying the output of the vector subtraction unit. Test machine.