JPS6158767B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for automatically adjusting the zero degree of the phase angle of a dynamic balance tester.

A dynamic balance tester generally uses a vibration detector that detects the signal _S1 from an unbalance detector such as a force detector, a mark placed on the test piece as the reference position of the test piece, irregularities on the surface of the test piece, and material. The magnitude and position of the unbalance are determined by the reference phase signal _S2 obtained by detecting changes in the signal _S1 with a detector such as a photocell or proximity switch.
The phase difference θ ₀ with S ₂ includes the geometrical arrangement angle Θ of both detectors and the phase characteristics α ₁ and α ₂ of each detector, so there is an imbalance with the reference position on the test specimen. The angle θ formed with the position generally does not match.
Therefore, it is necessary to correct θ ₀ by the above-mentioned Θ and an angle β corresponding to the angles α ₁ and α ₂ to obtain the true unbalance existence angle θ=θ ₀ −β.

In conventional devices, in order to perform this correction, a phase shifter in which the CR phase circuit is constituted by a monostable circuit or the like is used. Therefore, for example, when a test weight is attached to an arbitrary position on the test object and a reference phase signal is detected from that position, that is, when a test is performed using the position where the test weight is attached as the reference position, the phase shifter described above is used. The above-mentioned β was made to coincide with θ ₀ by manual operation, and the phase angle was adjusted to zero so that θ=θ ₀ −β=0. However, the circuit constituting the phase shifter has a disadvantage in that the intended phase shift angle depends on the input signal frequency, that is, the rotational speed of the test object.

The present invention was made in order to solve the above-mentioned drawbacks, and is a device that automatically adjusts the phase difference θ ₀ between the unbalance signal S ₁ and the reference phase signal S ₂ at a given rotation speed to zero. For the purpose of providing.

Embodiments of the present invention will be described below based on the drawings.

The drawings show circuit configuration diagrams of embodiments of the present invention.

The circuit includes an unbalance detector 1 and a reference phase detector 2 attached to the main body of a dynamic balance tester (not shown), their amplifiers 3, 4, a first reference pulse generator 5 based on a reference phase signal, and its output. The unbalanced signal is separated into two DC signals.
A two-component separation circuit 6 for conversion, a rectification circuit 7 for rectifying the unbalanced signal to obtain the amplitude A, and dividing the two DC signals output from the two-component separation circuit 6 by its output A to calculate the sine and cosine of the phase difference. A division circuit 8 that stores the output thereof, a storage circuit 9 that stores the output thereof, and a storage circuit 9 that stores the output thereof.
A multiplication/addition circuit 1 that performs a coordinate rotation operation on the two DC signals output from the two-component separation circuit 6 using the output of the two-component separation circuit 6.
0, a second reference pulse generator 12 that generates a frequency unrelated to the rotational speed of the test object; a two-component synthesis circuit 11 that introduces its output and synthesizes the output of the multiplication/addition circuit 10 into an alternating current signal; and the alternating current signal; and the reference phase of the second reference pulse, and an angle display meter 14 that displays the detected value.

Next, the operation of the circuit according to the embodiment of the present invention will be explained.

The signal detected by the unbalance detector 1 is amplified by the amplifier 3, and if A is the amplitude, ω ₁ is the angular velocity of the specimen, and θ ₀ is the phase difference from the reference phase, then S ₁ = Asin (ω ₁ t + θ ₀ ) is guided to the two-component separation circuit 6 as an unbalance signal. On the other hand, the signal detected by the reference phase detector 2 is guided to the first reference pulse generator 5 via the amplifier 4, and is synchronized with the rotational speed of the test object, and generates a pulse having the same phase as the reference phase and a pulse at the rotational speed mentioned above. , a pulse having a phase difference of 90° from the reference phase is generated and output to the two-component separation circuit 6. In the two-component separation circuit 6, the unbalance signal S ₁ = Asin (ω ₁ t + θ ₀ ) due to the above two pulses is transformed into DC signals x = Acos θ ₀ and y = Asin θ ₀ corresponding to the 90° component of the unbalanced force component. It is separated and converted and introduced into the arithmetic circuit 8 and the multiplication/addition circuit 10. In the arithmetic circuit 8, the above x and y are divided by the amplitude A obtained by the rectifier circuit 7 that rectifies the unbalance signal _S1 , and x/A=cosθ ₀ and y/A=sinθ
₀ is output to the memory circuit 9 via the switch 15. The switch 15 outputs the output _sinθ0 of the arithmetic circuit 8.
and cos θ are provided to select whether to introduce ₀ or 0 and 1 if separately set into the memory circuit 9,
A storage command switch 16 is also attached to the storage circuit 9. In the multiplication/addition circuit 10, coordinate rotation is calculated based on the principle of rectangular coordinate transformation using the outputs x, y of the two-component separation circuit 6 and the output of the storage circuit 9. That is, when the outputs of the memory circuit 9 are sin θ ₀ and cos θ ₀ , the following calculation is performed: X=xcos θ ₀ +ysin θ ₀ Y=−xsin θ ₀ +ycos θ ₀ , and the coordinates are rotated by θ ₀ .
When the outputs of the memory circuit 9 are 0 and 1, coordinates are not transformed as follows: X=x×1+y×0=x Y=−x×0+y×1=y. These DC signals X and Y are output to a two-component synthesis circuit 11, and in the two-component synthesis circuit 11, the DC signals X and Y are
The frequency ω ₂ /2π is determined by using the output of the second reference pulse generator 12, which generates two types of pulses with a phase difference of 90° and having a frequency ω ₂ /2π that is independent of the rotational speed of the test object. It is synthesized and converted into an AC signal. This AC signal is guided to a phase difference detection circuit 13, where the phase difference with the reference phase of the second reference pulse is detected and output to the angle display meter 14. When the output of the memory circuit 9 is 0 and _{1 ,} that is, when _the DC signal is The synthesized and converted AC signal becomes Asin(ω ₂ t+θ ₀ ), and the phase difference detection circuit 13 detects θ ₀ , and the angle display meter 14 displays θ ₀ . When the output of the memory circuit 9 is sinθ ₀ and cosθ ₀ , that is, when the DC signal is subjected to coordinate rotation by X=xcosθ ₀ +ysinθ ₀ Y=−xsinθ ₀ +ycosθ ₀ and θ ₀ , x=Acosθ ₀ , Since y=Asinθ _0, X=A, Y=0, and the AC signal synthesized and converted using ω ₂ by the two-component synthesis circuit 11 becomes Asinω ₂ t, so the phase difference is detected by the phase difference detection circuit 13. 0 is displayed on the angle display meter 14.

When using the above-described embodiment of the present invention, calibration is performed in the following procedure prior to actual measurement. That is, a test weight is attached to a reference position (0°) of a balanced test object such as a master rotor, and the measurement is performed. At this time, the memory command switch 16 is set to ON, that is, the output of the memory circuit 9 is equal to the input signal, and the switch 15 is set so that the signals of 0 and 1 respectively become the input signals of the memory circuit 9. . In this state, the above-mentioned θ ₀ is displayed on the angle display meter 14. Then, in that state, the indicated value of an unbalance amount meter (not shown) (which displays the amplitude A by introducing the output of the two-component synthesis circuit 11) is read.

Next, the switch 15 is operated to set the input signals to the memory circuit 9 to be sin θ ₀ and cos θ ₀ . As a result, coordinate rotation is performed and the angle display meter 1
4 will be displayed as 0. At this time, read the unbalance meter reading at the same time,
If the value is the same as the value before operating the switch 15, it means that the gain adjustment in the analog circuit portion of the rectifier circuit 7, divider circuit 8, etc. is correct, and after this confirmation, the memory command switch 16
is operated to put the memory circuit 9 into the memory state and complete the calibration operation.

If actual measurements are made in this state, the indicated value of the angle display meter 14 will be the phase offset amount θ ₀
The true unbalance angle will be displayed with the value reduced.

The reason for providing the switch 15 is to confirm the degree of gain adjustment of the analog circuit as described above, and also to ensure that the indicated value of the angle display meter 14 is correct from θ ₀ when the switch 15 is operated during the calibration operation. By checking that it becomes 0,
This is to confirm that the entire circuit is normal.

In the above embodiment, in order to obtain the amplitude A, the rectifier circuit 7 is not used, and the output of the two-component separation circuit ₆ is
You may use an arithmetic means that performs the calculation from ₀ to A = √ ² + ² , or
Furthermore, as a means to obtain sinθ ₀ and cosθ ₀ , the outputs of the two-component separation circuit 6 x=Acosθ ₀ and y=Asinθ
Of course, it is also possible to use an arithmetic means that obtains θ ₀ =tan ⁻¹ x/y from ₀ and calculates sin θ ₀ and cos θ ₀ .

As explained above, according to the present invention, the phase difference between the unbalance signal and the reference phase signal can be immediately adjusted to zero at any rotation speed of the test object by calculation based on the principle of coordinate rotation. During calibration, it is possible to compensate for the phase offset amount θ ₀ specific to the testing machine without manually adjusting a phase shifter or the like as in the conventional method. Moreover, since it does not depend on the input frequency at all, for example, in a dynamic balance tester that applies rotation by pressing a belt against the outer circumference of the test object, if the outer circumference of the test object differs, the rotation speed will differ and the input frequency will change. Therefore, with the conventional apparatus, calibration was required each time, but with the present invention, once the calibration is performed, there is no need to recalibrate even if the test specimen is changed.

Also, the X, Y of the new coordinate system that has been rotated
can also be converted to an oblique coordinate system or a force component coordinate system.

[Brief explanation of the drawing]

The drawings show circuit configuration diagrams of embodiments of the present invention. DESCRIPTION OF SYMBOLS 1... Unbalance detector, 2... Reference phase detector, 3, 4...... Divider, 5... First reference pulse generator, 6... Two component separation circuit, 7... Rectifier circuit,
8...Division circuit, 9...Memory circuit, 10...Multiplication/
Addition circuit, 11... Two-component synthesis circuit, 12... Second reference pulse generator, 13... Phase difference detection circuit,
14...Angle display meter.

Claims (1)

[Claims] 1 An unbalance detector that rotates a rotating body under test and detects an unbalance signal of the rotating body from the centrifugal force or vibration of the rotating body, and an unbalance detector that detects changes in the surface condition of the rotating body and generates a reference phase signal. In a motion balance testing machine equipped with a reference phase detector to determine the size and position of unbalance existing in the rotating body under test, the output of the reference phase detector is introduced to synchronize with the rotational speed of the rotating body under test. and a first reference pulse generating means for generating a pulse having the same phase as the reference phase and a pulse having a phase difference of 90° from the reference phase in synchronization with the rotation speed, the output of which is input, and the unbalance signal is Means for separating and converting into two DC signals related to the phase difference with the reference phase and corresponding to the 90° component of the unbalance signal, and calculating the sine and cosine of the phase difference from the DC signal. means for storing the calculation results; and calculation means for rotating the coordinates of the two DC signals by calculating the phase difference using the sine and cosine based on the principle of rotation of rectangular coordinates. A second reference pulse generation means that generates two types of pulses having a phase difference of 90 degrees from each other, which is unrelated to the rotational speed of the trial rotating body, and its output are introduced to synthesize the two components calculated by the above coordinate rotation. and means for detecting a phase difference between the combined output thereof and the reference phase of the second reference pulse, and is configured to automatically adjust the zero degree of the phase angle of the dynamic balance tester. Automatic angle zero adjustment device for dynamic balance testing machine.