JPH0676945B2 - Eccentricity correction method for balance tester and balance tester - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eccentricity correction method and a balance tester for electrically correcting the eccentricity of a support adapter that supports a device under test.

2. Description of the Related Art When measuring an imbalance of a device under test, it is necessary to correct the eccentricity present in a support adapter that supports the device under test in order to improve the accuracy of the measurement. Therefore, after attaching the DUT to the support adapter and rotating it to perform the first balance test, the attachment angle of the DUT to the support adapter is set to 180.
Rotate once and attach for the second balance test. This 2
An eccentricity correction vector was calculated from two eccentricity vectors indicating the imbalance obtained by the balance test, and an electrical method for correcting the eccentricity of the support adapter and the first balance test were performed. Sometimes the unbalance is corrected to 0, and the unbalance shown in the second balance test is corrected to 0. At the same time, the weight is attached to the DUT and the other half is corrected. There is a mechanical method of correcting the eccentricity of the support adapter by correcting the eccentricity of the support adapter.

Problems to be Solved by the Invention Mounting of the device under test on the support adapter is due to the fact that the position where the device under test comes into contact with the support adapter is not on the same perfect circle but slightly deviated. If the angle is different, the eccentricity of the support adapter will be different. As described above, when correcting the eccentricity of the support adapter by the two equilibrium tests in which the mounting angles differ from each other by 180 times, the deviation from the mounting angle The eccentricity that occurs when the DUT is attached at different angles cannot be corrected sufficiently.

The present invention has been invented in order to solve the above problems, and a balance tester capable of accurately correcting the eccentricity of the support adapter even when the DUT is attached in any direction. It is an object of the present invention to provide a method for correcting eccentricity of a support adapter and a dynamic balance tester capable of accurately performing a balance test on a device under test.

Means for Solving the Problems In order to achieve the above object, in the eccentricity correction method for a balance testing machine of the present invention, an angle obtained by dividing 360 degrees by N, which is an integer of 3 or more, is defined as M degrees. In this case, the steps of performing N number of balance tests by changing the mounting angle of the DUT to the support adapter by M degrees and showing the eccentricity caused by the unbalance of the DUT and the eccentricity of the support adapter Of calculating the vector by adding N eccentricity vectors obtained by the equilibrium test and dividing by N, and the center of rotation of the main spindle for measurement in which the DUT is attached via the support adapter and rotates. And a step of adding a correction vector signal corresponding to an eccentricity correction vector obtained by rotating the calculated vector by 180 degrees to a displacement signal indicating the displacement of the balance tester of the present invention. The synchronous rectifier circuit that separates the position signals into two orthogonal directions and generates two eccentricity vector separation signals of X and Y indicating the eccentricity vector and the mounting angle of the DUT to the support adapter are different by M degrees. And an arithmetic circuit for calculating an average value for each of the X eccentricity vector separation signal and the Y eccentricity vector separation signal from each of the N X and Y eccentricity vector separation signals obtained by the N kinds of balance tests. A vector generation circuit that generates a correction vector signal according to the output from the arithmetic circuit and an addition circuit that adds the correction vector signal to the displacement signal.

Action N eccentricity vectors indicating eccentricity caused by unbalance of the DUT and eccentricity of the support adapter are sampled. At this time, the influence of the eccentricity of the support adapter is slightly different in each eccentricity vector. By calculating the average value of the eccentricity vector separation signals indicating the X and Y direction components of each eccentricity vector, the eccentricity caused by the imbalance of the device under test is canceled and the eccentricity of the support adapter causes The value of the vector indicating the average of eccentricities that are slightly different from each other is calculated. A correction vector signal for canceling the vector indicating the calculated average is generated and added to the displacement signal.

Example One example of the present invention will be described below.

FIG. 1 is a block diagram showing a balance testing machine of the present invention. In the figure, the device under test 41 is attached to the measurement spindle 43 via a support adapter 42. The displacement of the rotation center of the measuring main shaft 43 is measured by the pickup 11 and becomes a displacement signal 31 which is input to one of the adding circuits 12.
Then, the output thereof is guided to the synchronous rectification circuit 13 and becomes a pair of signals of an X eccentricity vector separation signal 32X and a Y eccentricity vector separation signal 32Y indicating the components of the eccentricity vector in two orthogonal directions, and the display unit 15 And the arithmetic circuit 14, respectively. The output from the arithmetic circuit 14 is sent to and stored in the storage circuit 17 in the vector generation circuit 16, and the stored value becomes the correction vector signal 33 having the waveform of the pseudo sine wave by the chopper circuit 18, and the displacement signal. 31 is led to the other input of the adder circuit 12 to which it is input. Further, a phase detector 20 for detecting the rotational position of the measuring main shaft 43 is provided, and a position signal is output every time the rotational position of the measuring main shaft 43 reaches a certain angle.
34 is generated and sent to the two-phase pulse generation circuit 19. Two
The phase pulse generation circuit 19 generates two pulse signals whose phases are different from each other by 90 degrees in synchronization with the position signal 34 and sends them to the vector generation circuit 16 and the synchronous rectification circuit 13.

FIG. 2 is a block diagram showing details of the arithmetic circuit 14.
The X eccentricity vector separation signal 32X is input to the adder 51, and its output is input to the memory 52. The output of the memory 52 is led to the inputs of the division circuit 54 and the other memory 53, and the output from the memory 53 is the adder.
It is connected to the other input of 51. The output of the division circuit 54 is sent to the vector generation circuit 16 of FIG. Memories 52, 53 sample and store inputs according to control signals not shown, respectively. The Y eccentricity vector separation signal 32Y has the same configuration, and the division circuit 14 is composed of the above two sets.

The operation will be described below with reference to FIGS. 1 and 2.

Its amplitude is proportional to the displacement amount of the rotation center of the measuring spindle 43,
The displacement signal 31, which is a sine wave whose period is equal to the rotation speed of the measurement spindle 43, is eccentricity vector indicating eccentricity in two orthogonal components by the synchronous rectification circuit 13 connected through the adder circuit 12. It is converted into a separated signal 32.

The angle obtained by dividing 360 degrees by an integer N of 3 or more is M degrees. Then, the mounting angle of the DUT 41 to the support adapter 42 is first attached to 0 degree or the like to perform a balance test, the voltage of the eccentric vector separation signal 32X at that time is set to a1X, and then the DUT 41 is supported. It is rotated by M degrees with respect to 42 and the second equilibrium test is performed. The voltage of the eccentricity vector separation signal 32X at that time is a2X. Similarly, in the same manner, anX will be used for the Nth balance test.

Since the initial value of the memory 53 is set to 0, the output of the adder 51 performing the first balance test is a1X. The voltage is stored in the memory 52, stored in the memory 53 when the voltage is stably output from the memory 52, and the voltage is input to the adder 51. Next, when the second balance test is performed, the voltage of the eccentric vector separation signal 32X becomes a2X, and the adder
The voltage of a1X + a2X is output from 51. This voltage is stored in the memories 52 and 53 at the same timing as above. When the Nth balance test is completed by the same operation in sequence,
The memory 52 stores the addition result of the voltages from a1X to anX. Since the arithmetic circuit 54 multiplies this addition result by 1 / N, its value becomes a voltage indicating the average of the voltages from a1X to anX.

The same applies to the Y eccentricity vector separation signal 32Y. FIG. 3 is a block diagram showing another embodiment of the arithmetic circuit 14. The X eccentricity vector separation signal 32X is connected to the inputs of N (in the figure, N = 3 is shown) memories 61, and the output of each memory 61 is added by the adder 62, and then the division circuit 63 Is multiplied by 1 / N. Memory 61a is a1X, 61b is a2
X and 61c store a3X, respectively. At the output of the division circuit 63, a value obtained by averaging the voltages of a1X to a3X appears.

FIG. 4 is an explanatory diagram showing the eccentricity vector when N = 3. The eccentricity vector 61 is shown as a combination of a vector (hereinafter abbreviated as unbalance vector) 63 indicating the unbalance of the DUT 41 and a vector (hereinafter abbreviated as adapter vector) 62 indicating the eccentricity of the support adapter 42. Unbalanced vector 63
When the mounting angle of the DUT 41 with respect to the support adapter 42 is rotated, it rotates by the same angle as the rotation angle. N
= 3, M = 120 degrees, and the unbalanced vectors 63 have angles different from each other by 120 degrees and have the same length. Since the adapter vector 62 has a mounting error caused by an error in the processing accuracy of the DUT 41 or the support adapter 42, if the mounting angle of the DUT 41 is different, the adapter vectors 62 are slightly different from each other. Is occurring. When a vector obtained by averaging the eccentricity vector 61 is calculated by the arithmetic circuit 14,
The unbalanced vectors 63 cancel each other out, and only the adapter vector 62 remains, but that vector becomes a vector indicating the center of a triangle having the tips of the three adapter vectors 62 as vertices, and this vector is eccentric to the support adapter 42. Is a vector indicating the average of. The vector obtained by rotating this vector by 180 degrees becomes the correction vector 64, and the vector generation circuit 15 generates the correction vector signal 33 corresponding to the correction vector 64. The eccentricity of the support adapter 42 is corrected by adding it to the displacement signal 31 via the adder circuit 12.

Note that the present invention is not limited to the above-described embodiment, and the arithmetic circuit 14 may have another circuit configuration that performs the same operation, for example, by providing an A / D conversion circuit or a CPU to perform the arithmetic circuit. is there.

EFFECTS OF THE INVENTION The test object is attached to the support adapter at three or more different attachment angles that are equal to each other, and a balance test is performed at each of the attachment angles. The vector obtained by averaging the eccentricity vector obtained as a result is calculated, and the eccentricity of the support adapter is corrected by the calculated vector, so even when the DUT is attached in any direction, An eccentricity correction method for a support adapter of a balance tester capable of accurately correcting eccentricity of a support adapter, and a balance tester capable of accurately performing a balance test of a DUT. It will be possible.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the balance testing machine of the present invention, and FIG. 2 is a block diagram showing details of the arithmetic circuit 14.
FIG. 3 is a block diagram showing another embodiment of the arithmetic circuit 14, and FIG. 4 is an explanatory diagram showing an eccentricity vector when N = 3. 11 …… Pickup, 12 …… Adding circuit, 13 …… Synchronous rectifying circuit, 14 …… Computing circuit, 16 …… Vector generating circuit.

Claims (2)

[Claims] 1. When an angle obtained by dividing 360 degrees by N, which is an integer of 3 or more, is M degrees, N types of balance tests are performed by changing the mounting angle of the DUT to the support adapter by M degrees. The steps of performing and showing the eccentricity caused by the unbalance of the DUT and the eccentricity of the support adapter, and adding N eccentricity vectors obtained by the N kinds of balance tests and dividing by N An eccentricity obtained by rotating the calculated vector by 180 degrees to a displacement signal indicating the displacement of the rotation center of the measuring main shaft in which the DUT is attached via the support adapter and rotates through the step of calculating the vector. And a step of adding a correction vector signal corresponding to the correction vector. 2. When the angle obtained by dividing 360 degrees by N, which is an integer of 3 or more, is M degrees, the displacement signal from the pickup is separated into two orthogonal directions and X and Y of eccentricity vector are shown. The synchronous rectification circuit that converts two eccentricity vector separation signals and the mounting angle of the DUT to the support adapter are set to M
Each N obtained by N kinds of balance tests performed at different times
An arithmetic circuit that calculates an average value of each X eccentricity vector separation signal and each Y eccentricity vector separation signal from the X and Y eccentricity vector separation signals, and a correction vector signal is generated according to the output from this arithmetic circuit. A balance testing machine comprising a vector generation circuit and an addition circuit for adding the correction vector signal to the displacement signal.