JPS62127639A - Balancer - Google Patents

Abstract

PURPOSE:To obtain the balancer of simple constitution by digitizing the output of an acceleration sensor with sampling pulses having a specific period synchronized with a signal for the rotation reference of a rotary body and calculating the unbalance quantity and unbalance position of the rotary body by a digital calculating means. CONSTITUTION:A synchronizing oscillator 102 and an index sensor 1 constitute a sampling pulse generating part 104 and outputs sampling pulses 105 for one period synchronized with the signal 4 for the rotary phase reference of the rotary body 21 to be tested. The acceleration sensor 2 outputs an unbalance quantity (acceleration) signal 5 to an A/D conversion part 106. The A/D conversion part 106 digitizes the signal 5 at the timing of the sampling pulses 105 and sends out a digital signal 107 to a digital computer 101. The digital signal 107 is coded and the digital computer 101 computes the unbalance quantity and unbalance position based on the coded data.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention provides a method for determining the position and size of unbalance of a rotating body in various devices including a rotating body, such as a magnetic disk drive. This relates to a balancer used for.

"Technical Background of the Invention" □ Conventionally, in order to eliminate vibrations caused by unbalance of a rotating body, it has been carried out to balance the rotation. A testing machine for achieving this kind of balance is called a balancer, and a so-called dynamic balancer, which balances the rotating body behind the balancer while it is in operation, takes into account the influence of the surrounding structure on the rotating body while it is in operation. It is possible to achieve a balance by including this, and it is extremely effective.

Conventionally, such a balancer has been constructed as shown in FIG. In the same figure? 1 indicates a test object which is a rotating body. This test object 21 has a cylindrical shape, and has a +111
22, for example, in the direction of arrow X. An index sensor 1 is provided close to a predetermined position on the outer periphery of the test object 21 . This index sensor 1 detects a mark placed on the outer periphery of the test object 21 at a location facing the index sensor 1 using, for example, an optical detection element, and detects the rotational phase distance of the test object 21. Detect signal 4 which becomes -chino. 2 (31 accelerated polishing Renly)
shows. The acceleration sensor 2 is fixedly provided in a predetermined positional relationship with the test object 21, in contact with the outer periphery of the test object 21 or the support 22. When the acceleration sensor 2 detects acceleration in the horizontal direction (arrow Y), it detects the amount of unbalance that the test object 21 vibrates in the horizontal direction, and detects the amount of unbalance that the test object 21 vibrates in the horizontal direction. Outputs 5. For example, the acceleration sensor 2 is moved horizontally by a protruding piece lightly pushed toward the center of the shaft 22 by a spring, or by an unbalance when the test object 21 rotates. It consists of a lens that outputs a signal (quantity). 3 indicates a balance measuring device. Balance measuring device 3
takes in the output signal 4 of the index sensor 1 and the output signal 5 of the acceleration sensor 2, processes these signals with an analog circuit, and outputs the output signal 6, which is the absolute value of the output signal 5 of the acceleration sensor 2, and the output signal 6, which is the absolute value of the output signal 5 of the acceleration sensor 2. At the position where the absolute maximum value is reached,
An output signal 7 indicating which of the output signals 4 of the index sensor 1 has a C phase difference is sent out.

Based on the output signals 6 and 7 thus obtained,
The unbalance amount and unbalance position are (unbalance amount) - (constant determined by the test object) x (output 6) (unbalance position) = (constant determined by the test object)
It is obtained by calculating X (output cuff). Based on the unbalance amount and unbalance position obtained in this way,
Attach the required amount of correction weight to the relevant location of the test object 21 (
(including correction cutting).

[Problems with the Background Art] As described above, the conventional balancer requires a balance measuring device consisting of an analog circuit, and has the disadvantage that the structure cannot be seen. In addition, in the case of single-plane balance (horizontal direction only) as described above, one balance measuring device is sufficient, but in the case of multi-plane balance (N > plane balance, N balance measuring devices are required). This has the disadvantage that the configuration becomes increasingly complex and large.Furthermore, in the case of -plane balance, calculations to obtain the above-mentioned unbalance amount and unbalance position are relatively easy, and can be done using a so-called calculator, etc. Even if the calculation is done by hand, including using , it is necessary to find solutions to simultaneous equations with 2N elements, which requires complicated calculations and takes C time.

[Object of the Invention] The present invention was made in view of the drawbacks of the conventional balancer as described above.
To provide a parallax that does not make the configuration complicated or humanized even when determining surface balance, and also simplifies calculations for determining the amount of unbalance and the position of unbalance. It is.

[Summary of the Invention] Therefore, in the present invention, an unbalance amount signal of a rotating body is digitized by an i57 from an acceleration sensor using a sampling pulse of a predetermined period synchronized with a signal serving as a rotation reference of the rotating body. It is necessary to achieve the above object by calculating the unbalance amount and unbalance position of the rotating body using digital calculation means based on the digitized data.

Embodiment of the Invention FIG. 1 shows a balancer 100 according to an embodiment of the invention. In the figure, the same components as in Figure 5 include:
The same reference numerals are given, and the explanation thereof will be omitted. Reference numeral 101 denotes a program-controlled digital computer, which constitutes digital calculation means. This digital computer 101 detects when the rotation of the test object 21 has become constant.
It is detected that a predetermined period of time has passed since the index sensor 1 was rotated, or that the output of the index sensor 1 has started to be output at a constant cycle, and sends an oscillation start signal 103 to the synchronous oscillator 102. The synchronous oscillator 102 and the index sensor 1 constitute a sampling pulse generator 104, which is a rotating body under test. Sampling pulse 1 for one period synchronized with signal 4, which is the rotational phase reference of 1.
Output over 05. In other words, the synchronous oscillator 102 generates, for example, 4m (m; 103 to 1024) 1-non-shilling pulses in synchronization with the signal 84 (see FIG. 2) that is output from the index sensor 1 and serves as the rotation reference of the test object 21. 105 (see Figure 2) for one lap! I] Excerpt 9
do. Here, the number of 1 non-shilling pulses 105 is /
4. m is a multiplication of 2, which is easy to implement in terms of hardware, and is about this level (m: 103 to 1024).
This is because the error can be sufficiently removed with a sampling number of . The acceleration sensor 4-2 outputs an unbalance amount (acceleration) signal 5 as shown in Fig. 2 (5), and the A/
It reaches the D conversion section 106.

The A/D converter 106 digitizes the signal 5 as shown in FIG. 2 at the timing of the sampling pulse 105, and sends it to the digital calculator 101 as a digital signal 107. The digital signal 107 is coded, and the computer 101 calculates the unbalance amount and unbalance position based on the digital i'i- code data. There are various methods for performing this calculation, but generally it is considered to be a calculation using Fourier transform. but,
According to this Fourier transformation, 81 cotton is a congratulation 1, which takes time and is no different from the conventional example.

Therefore, in this embodiment, the signal with the sampling or rotational phase of 33i%+ is synchronized with the output signal 4 of the index sensor 1, and the output signal 5 of the acceleration sensor 2 is also synchronized with the output signal 4. Considering that, one cycle of the output signal 4 includes one cycle of the output signal 5 of the acceleration sensor 2, and by processing this output signal using 412 weighting function data as follows. , it becomes possible to easily calculate the amount of unbalance and the unbalance position.

If the function of the output signal 5 of the acceleration sensor 2 is SA, then
S(,=A I Cos (tJ (+ A2 sin
(1) Shi and calligraphy (Puru. Next, Figure 4 (SR1), (
Weighting functions SR1 and SR2 as shown in SR2> are stored in a weighting function holding section (storage section) of the digital h] hooking machine 101. Here, the φ function SR1 rises from zero to plus 1 at the start of one cycle of the output signal 4 of the index sensor 1, and falls to minus 1 when the output signal 4 of the index sensor 1 advances by J/4.
It is a function that rises to plus 1 when the history advances by 1/2 and becomes zero at the end of 1 cycle, and the weighting function 5R21 changes from zero to plus 1 at the start of 1 cycle of the output signal @ 4 of index sensor 1. It is a function that advances by 1-/2 and falls to minus 1, and then advances by 1-/2 and becomes zero at the end of one cycle.

Each of the above functions SA has a separate weighting function s+<i, SR2. Note that 4m is the number for one cycle of the sampling pulse 105.

It is determined by

Therefore, the arithmetic unit of the digital computer 101 calculates A
/Sampling data given from the D converter 106 (
That is, the function SA) is separately multiplied by the two weighting functions SR1 and SR2 in the weighting function holding unit to obtain the average value s1. s2 (according to equations (1) and (2)), and then calculate this average value S
1. When Δ and φ are obtained from equations (3) and (4) using S2, Δ is the unbalance amount and φ is the unbalance position (phase difference from the index mark).

In the above case, even if the function SA contains harmonic components, as a result of the Fourier expansion of the steering functions SR1 and SR2, the even-order term becomes 12o, and the odd-order term becomes 1/
(2n+1>) Therefore, the asynchronous component consisting of odd-order terms can be ignored if the Leanbling number is increased by one, and it is considered that there is no influence from harmonics after all.

In the paralleler 100 configured as described above, after the test object 21 rotates and the rotation becomes constant, the output signal 5 of the acceleration sensor 2 is digitized with respect to the output signal 401 period of the index sensor 1. It is sufficient to import the data into the digital computer 101 and perform calculations using equations (1) to (4) in the digital computer 101.

Although the above is a case of one-sided balance, in the case of two-sided balance, the Paran-'j-100A is constructed as shown in FIG. An acceleration sensor 28 that detects an unbalance amount (acceleration) signal in the vertical direction (direction of arrow Zh) is provided to be able to detect, for example, vibrations on the bottom surface of the test object 21.
, 2A output signal g5.5A is selected by the analog switch 108 and guided to the A/D converter 106. The analog switch 108 is switched by the moxibustion signal 109 output from the digital signal 11JIOIA.

The other functions of the digital computer 101A are the same as those of the digital computer 101 in FIG. In such a parallelizer 100A, after the test object 21 rotates and the rotation becomes constant, the first oscillation start signal 103 is outputted, and the output signal 4 of the index sensor 1 is outputted.
For the same gate, the analog switch 108 is controlled to select the output signal 5 of the acceleration sensor 2, and the calculations of equations (1) to (4) are performed on the digital signal of the output signal 5, and the horizontal angle is calculated. Find the balance amount and unbalance position.

Next, the second oscillation start signal 103 is output, and the analog switch 108 is controlled by the switching signal 109 to perform the same processing as above on the output signal 5A of the acceleration sensor 2A, thereby reducing the vertical imbalance. Find the amount and unbalance position.

Generally, in the case of multi-plane balance, one acceleration sensor is provided for each of the N directions in which unbalance is sought (therefore, N at rest), and the sensor is guided to an analog switch, and its output signal is Select one. Then, based on this output signal, the amount of unbalance and the unbalance position are determined. Such processing may be performed N times one after another by switching the analog switch.

In this way, according to the present embodiment, a balance measuring device consisting of an analog circuit is not required, whether it is a -plane balance or a multiplane balance, and the configuration can be simplified and miniaturized. In addition, in calculations for determining the amount of unbalance and the unbalance position, an algorithm (based on equations (1) to (4)) that takes into account the characteristics of the circuit up to obtaining the digital signal of the acceleration sensor is used, so in the case of multi-plane balance, However, as a digital computer, it is sufficient to use a small and simple one with only a few chips, making it possible to miniaturize and simplify the overall device and reduce costs.

In the above embodiment, the sampling pulses were synchronized with the output signal 4 of the index sensor 1 and used at regular intervals, but an asynchronous pulse train was generated and this was applied at a predetermined frequency according to the output signal @4. It may be output for a period of time, or it may be extracted mechanically (for example, by providing 4m protrusions on the outer periphery of the test object 21 and detecting them) or optically from the test object 21. However, it is sufficient that the configuration generates sampling pulses of a predetermined period synchronized with the rotational phase reference signal.

[Effects of the Invention] As explained above, according to the present invention, the configuration is simple because it does not include a balance measuring device using an analog circuit, and even when performing multi-sided balance, the number of balance measuring devices does not increase. The configuration does not become complicated or large. In addition, sampling of the unbalance amount (acceleration) signal is performed using a sampling pulse of a predetermined period that is synchronized with the rotation reference signal, and furthermore, the unbalance amount (acceleration) signal is synchronized with the rotation reference signal. Therefore, it is possible to perform processing according to a predetermined algorithm using the unbalanced ff1 (7Jfl speed) signal for the predetermined period, so there is an advantage that calculations for determining the amount of unbalance and the unbalance position can be easily performed.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIGS. 2 and 3 are waveform diagrams for explaining the operation of the embodiment shown in FIG. 1, and FIG. 4 is a block diagram of an embodiment of the present invention. A block diagram of an embodiment of
FIG. 5 is a block diagram of a conventional balancer. 1... Index sensor 2.2A... Acceleration sensor 21... Test object (rotating body) 101, l0IA... Digital computer (digital calculation means) 102... Synchronous oscillator 104... Sampling pulse Generating part 106...A
/D converter 10B...analog switch

Claims (2)

[Claims] (1) A sampling pulse generator that generates sampling pulses for a predetermined period in synchronization with a signal serving as a rotational phase reference of the rotating body, an acceleration sensor that detects an unbalance amount signal of the rotating body, and an output of this acceleration sensor. A balancer comprising: an A/D converter that digitizes the sampling pulse; and a digital calculator that calculates the unbalanced position and magnitude of the rotating body based on the output of the A/D converter. (2) The digital calculation means includes a weighting function holding section that holds two weighting function data, and a weighting function holding section that separately multiplies the data taken in from the A/D conversion section by the above two weighting functions, and separates the resulting data. The unbalanced position of the rotating body and its magnitude are determined based on the relationship between the coefficient of the cosine wave component and the coefficient of the sine wave component of the data taken in from the A/D converter and the average value. The balancer according to claim 1, further comprising a calculation section that calculates .