JP5198920B2 - Dynamic balance testing machine - Google Patents

Description

  The present invention relates to a dynamic balance testing machine.

  Conventionally, a mark indicating the reference position has been provided on the surface of the workpiece, and this mark is detected by a position sensor to generate a rotation reference signal, and the rotation reference signal is compared with the drive pulse of the servo motor for driving the workpiece. A dynamic balance testing machine that accurately detects the rotational position (angle) of a workpiece is known (see, for example, Patent Document 1). In this type of testing machine, the drive pulses of the servo motor are counted by a counter, and the workpiece is automatically stopped at a measured unbalance angle or a preset fixed angular position based on the count value. The counter is reset every time the rotation reference signal is generated, and the count value is associated with the angle from the reference position.

JP 2005-91317 A

  By the way, when the workpiece is driven by a servo motor through a belt as in the test machine described in Patent Document 1, an error may occur between the rotation of the servo motor and the rotation of the workpiece. For this reason, for example, when the servo motor is stopped at a predetermined count value, the counter may be reset before the count value is reached, and the servo motor may not be stopped.

The dynamic balance testing machine according to the present invention includes a driving means for rotationally driving a workpiece, a reference signal output means for outputting a rotation reference signal every time the workpiece rotates by a predetermined amount, and a pulse signal corresponding to the driving amount of the driving means. A pulse signal output means for outputting, a first counter means for counting the pulse signal output from the pulse signal output means and resetting the counter in synchronization with the rotation reference signal output from the reference signal output means; A second counter that counts the pulse signal output from the pulse signal output means and rewrites the count value to the count value of the first counter means before reset in synchronization with the rotation reference signal output from the reference signal output means And whether the count value of the first counter means and the count value of the second counter means match the target count value. It comprises a constant determining means, when at least one of the count value by the determination means determines that coincides with the target count value, and a drive control for decelerating or stopping the rotation of the workpiece by the driving means.
The driving means may be configured as a belt-type driving device that drives a workpiece via a belt, and the pulse signal output means may be configured as a rotary pulse generator that detects the amount of rotation of a rotating body wound around the belt.
A first comparator for comparing the count value of the first counter means and the target count value, a second comparator for comparing the count value of the second counter means and the target count value, and a first counter When at least one of the count value of the means and the count value of the second counter means matches the target count value, the determination means may be constituted by an output device that outputs a coincidence signal for operating the drive control means. .
Based on the unbalance detection means for detecting the unbalance amount and unbalance angle of the work rotated by the drive means, the unbalance amount and unbalance angle detected by the unbalance detection means, and the signals from the reference signal output means and the pulse signal output means, It may further include target count value setting means for setting the target count value.

  According to the present invention, the first counter means that is reset in synchronization with the rotation reference signal and the second counter means that is rewritten to the count value before reset in synchronization with the rotation reference signal are provided. Since the rotation of the workpiece is decelerated or stopped when the value matches the target count value, the current position of the workpiece can be reliably detected even when the first counter means is reset.

Hereinafter, with reference to FIGS. 1-5, embodiment of the dynamic balance testing machine by this invention is described.
FIG. 1 is a diagram showing a schematic configuration of a dynamic balance testing machine according to an embodiment of the present invention. Both ends of the work W are rotatably supported by bearings 1a and 1b. The bearings 1a and 1b are elastically supported by a testing machine frame (not shown) via spring elements. When the workpiece W rotates, the bearings 1a and 1b vibrate according to the unbalance of the workpiece W. The vibrations of the bearings 1a and 1b are detected by pickups 2a and 2b which are moving coil type vibration detection sensors and piezoelectric element type force detection sensors, and the unbalance of the workpiece W is measured.

  A pulley 4 is attached to the output shaft 3 a of the motor 3, and a belt 5 is wound from the outer peripheral surface of the pulley 4 to the outer peripheral surface of the workpiece W. The motor 3 is a servo motor that is driven by a pulse signal, and the workpiece W is rotated via the belt 5 by the driving of the motor 3.

  A reference portion 7 such as a mark for representing a reference position is provided on the surface of the workpiece W, and a non-contact type reference position sensor 8 (for example, a laser sensor) is disposed facing the reference portion 7. . When the workpiece W rotates, the reference position sensor 8 generates a rotation reference signal on a pulse every time the reference portion 7 passes through the front surface of the workpiece W.

  The rotation of the pulley 4 is detected by the rotary encoder 6. The rotary encoder 6 is built in the motor 3 or provided outside the motor 3 and generates a pulse signal corresponding to the amount of rotation of the pulley 4. The rotation angle of the workpiece W and the number of pulses of the rotary encoder 6 are proportional to each other. For example, each time the workpiece W rotates once, the rotary encoder 6 generates N0 pulse signals. Hereinafter, N0 is referred to as a reference pulse number.

  The reference pulse number N0 varies depending on the size of the workpiece W. When the size of the workpiece W is changed, before the dynamic balance test is performed, the workpiece W is slowly rotated once to detect the number of pulses for one rotation, and this is stored as the reference pulse number N0. If 360 ° is divided by this reference pulse number N0, the rotation angle of the workpiece W per pulse can be obtained.

  Signals from the pickups 2a and 2b, the rotary encoder 6 and the reference position sensor 8 are input to the control device 10, respectively. The control device 10 includes a CPU, a ROM, a RAM, and other peripheral circuits (such as an AD converter and an amplifier), and stores a reference pulse number N0 in advance. Based on these input signals, the control device 10 calculates the magnitude and direction (angle from the reference position) of the unbalance between the left and right sides of the workpiece W, and outputs the calculation result to the display 11.

  Based on the calculation result, the unbalanced portion of the workpiece W is rotated to the position of the unbalance correction drill, for example. Then, the workpiece surface is punched by an amount corresponding to the unbalance amount by a drill, and the unbalance of the workpiece W is removed. When rotating the workpiece W, the control device 10 counts the pulse signal from the rotary encoder 6 and resets the counter when the rotation reference signal is output from the reference position sensor 8. As a result, the angle from the reference portion 7 and the count value are associated with each other, the rotational speed of the motor 3 is controlled based on the count value, and the workpiece W can be stopped at a predetermined position.

  This point will be described with a specific example. For example, a procedure for stopping the workpiece W at the target position when the count target value Na (<N0) corresponding to the angle of the unbalanced portion of the workpiece W is 2000 will be described. At this time, if there is no deviation in the correspondence between the rotation angle of the pulley 4 and the rotation angle of the workpiece W, as shown in FIG. 3A, before the rotation reference signal is output from the reference position sensor 8, that is, the workpiece. Before W makes one revolution, the count value N reaches the target value Na (= 2000). When the count value N reaches the target value Na, the control device 10 outputs a coincidence signal and stops the rotation of the motor 3.

  However, in reality, there is a difference between the correspondence relationship between the rotation angle of the pulley 4 and the rotation angle of the workpiece W due to expansion / contraction or slip of the belt 5, rattling of the drive unit, or the like. Considering the accuracy of drilling when removing unbalance, if this deviation is about 10% of the reference pulse number N0, it is an allowable range of error, and there is no problem in practical use.

  However, when the target count value Na is close to the reference pulse number N0, even if the error is within the allowable range, the rotation angle of the workpiece W exceeds the pulse number of the rotary encoder 6 due to the error, and the result is as shown in FIG. As shown, the rotation reference signal may be output before the count value N reaches the target value Na. In this case, since the counter is reset when the rotation reference signal is output, the control device 10 does not output the coincidence signal and cannot stop the rotation of the motor 3. In order to solve such a problem, the present embodiment configures the control device 10 as follows.

  FIG. 2 is a block diagram showing a main configuration of the dynamic balance testing machine according to the present embodiment. The control device 10 includes a first counter 11 and a second counter 12, a first comparator 13 and a second comparator 14, a target value setting circuit 15, and an OR circuit 16. In the following, the count value of the first counter 11 is represented by N1, and the count value of the second counter 12 is represented by N2.

  The first counter 11 and the second counter 12 each count the pulse signal from the rotary encoder 6. The count value N1 of the first counter 11 is reset to zero in synchronization with the rotation reference signal from the reference position sensor 8. The count value N2 of the second counter 12 is rewritten to the count value N1 (current value before reset) of the first counter 11 in synchronization with the rotation reference signal from the reference position sensor 8.

  The target value setting circuit 15 sets the count target value Na. This count target value Na is automatically set by, for example, measuring the unbalance of the workpiece W in advance, and corresponds to the number of pulses counted by the rotary encoder 6 from the reference portion 7 to the unbalance portion. It is also possible for the user to directly input the angle from the reference unit 7 to the stop target position and set a fixed count value Na.

  The first comparator 13 compares the count value N1 of the first counter 11 with the target value Na, and outputs a match signal when they match, that is, when the count value N1 reaches the target value Na. The second comparator 14 compares the count value N2 of the second counter 12 with the target value Na, and outputs a match signal when they match, that is, when the count value N2 reaches the target value Na.

  The logical sum circuit 16 outputs a coincidence signal when a coincidence signal is output from at least one of the first comparator 13 or the second comparator 14. When the coincidence signal is output from the OR circuit 16, the rotation stop of the motor 3 is commanded, and the rotation of the motor 3 is stopped.

  The main operation of this embodiment will be described. It is assumed that the motor 3 is driven with the target count value Na being 2000 and the rotation of the work W precedes the rotation of the pulley 4. In this case, as shown in FIG. 4, before the count value N1 reaches the target value Na (for example, N1 = 1997), the rotation reference signal is output from the reference position sensor 8, and the first counter 11 is reset. For this reason, the coincidence signal is not output from the first comparator 13.

  At this time, the count value N2 of the second counter 12 is rewritten to the count value N1 of the first counter 11 in synchronization with the rotation reference signal, and the second counter 12 counts the number of pulses following this count value N1. Thereafter, when the count value N2 of the second counter 12 reaches the target value Na (= 2000), the second comparator 14 outputs a coincidence signal. As a result, the OR circuit 16 outputs a coincidence signal, and the rotation of the motor 3 is stopped.

  If the rotation of the workpiece W is delayed from the rotation of the motor 3, the count value N1 of the first counter 11 reaches the target value Na before the rotation reference signal is output from the reference position sensor 8, and the first value The comparator 13 outputs a coincidence signal. As a result, the OR circuit 16 outputs a coincidence signal, and the rotation of the motor 3 is stopped.

  Although the workpiece W is stopped at the count target value Na, the count value, for example, 180 ° before the stop target value is set as the count target value Na, and the count values N1 and N2 coincide with the target count value Na. Alternatively, the count target value Na may be rewritten to the stop target value, and the workpiece W may be decelerated. Thereafter, when the count values N1 and N2 coincide with the count target value Na, the rotation of the workpiece W may be stopped. That is, not only the stop position but also the deceleration start position may be detected.

According to the present embodiment, the following operational effects can be achieved.
(1) Counters 11 and 12 that count pulse signals according to the rotation of the motor 3 and comparators 13 and 14 that compare the count values N1 and N2 of the counters 11 and 12 with the target value Na are provided in duplicate. When the rotation reference signal is output from the rotation reference sensor 8, the first counter 11 is reset and the count value N2 of the second counter 12 is rewritten to the count value N1 of the first counter 11. Thus, even when one counter 11 is reset, the coincidence signal can be output by the other counter 12, and even if the rotation of the work W precedes the rotation of the pulley 4, the motor 3 is decelerated. The rotation of the workpiece W can be stopped by reliably detecting the start position and the stop position.

(2) When the coincidence signal is output from any of the comparators 13 and 14, the rotation of the motor 3 is changed. Therefore, not only when the rotation of the workpiece W precedes but also when the pulley 4 precedes the rotation. The rotation of the motor 3 can be changed.
(3) Since the belt 5 is wound around the workpiece W and the pulley 4 and the rotation of the pulley 4 is detected by the rotary encoder 6, the position detection of the workpiece W in the belt type dynamic balance testing machine is easy.
(4) Since the control device 10 sets the target count value Na for removing the unbalance of the workpiece W based on the signals from the pickups 2a and 2b, the rotary encoder 6, and the reference position sensor 8, the workpiece W is easily unbalanced. Can be removed.

  The configuration of the reference signal output means is not limited to that described above. Although the rotation of the pulley 4 is detected by the rotary encoder 6, the configuration of the pulse signal output means is not limited to this as long as a pulse signal corresponding to the driving amount of the motor 3 is output.

  In the above embodiment, the pulse signal of the rotary encoder 6 is counted, the first counter 11 (first counter means) that is reset in synchronization with the rotation reference signal and the pulse signal are counted, and the rotation reference signal is The second counter 12 (second counter means) that is rewritten in synchronization with the count value N1 of the first counter 11 is provided, and the comparators 13 and 14 compare the count values N1 and N2 with the target value Na. As long as it is determined whether or not any one of the count values N1 and N2 matches the target count value Na, the configuration of the determination unit may be any. When the coincidence signal is output from the OR circuit 16 (output device), the drive speed of the motor 3 is changed by the signal from the control device 10, but the drive control means may have any configuration.

  The unbalance amount and unbalance angle of the workpiece W are detected by the pickups 2a and 2b as unbalance detection means, and based on the detected unbalance amount and unbalance angle and signals from the rotary encoder 6 and the rotation reference sensor 8, the control device 10 (target Although the target count value Na is set by the value setting circuit 15), the configuration of the target count value setting means is not limited to this. Although the belt 5 is wound around the workpiece W and the pulley 4 and the workpiece W is rotated by driving the motor, the configuration of the driving means is not limited to this.

  For example, as shown in FIG. 5 (a), the boat-shaped frame 101 is elastically supported with respect to the base 100, the workpiece W is rotatably supported by the boat-shaped frame 101, and the belt 103 is wound around the pulleys 102a to 102c. The belt 103 is brought into sliding contact with the workpiece W, the pulley 102a is driven by the motor 104 to rotate the workpiece W, and the vibration of the boat-shaped frame at that time is detected by a sensor to measure the unbalanced amount of the workpiece W. Also good. In this case, the rotation amount of the pulley 102a as the rotating body may be detected by a rotary encoder or the like that is a pulse sensor. You may detect the rotation amount of the other rotary bodies 102b and 102c by which the belt 103 is wound. As shown in FIG. 5B, the rotation shaft 110 of the workpiece W may be supported by a pair of rollers 105 elastically supported from the base 100, and the workpiece W may be rotated by the rotation driving of the roller 105. That is, the dynamic balance testing machine may be a roller drive system instead of a belt drive system.

  In the above embodiment, the workpiece W is supported horizontally, but may be supported vertically. That is, the present invention is not limited to the dynamic balance testing machine of the embodiment as long as the features and functions of the present invention can be realized.

The figure which shows schematic structure of the dynamic balance testing machine which concerns on embodiment of this invention. The block diagram which shows the principal part structure of the dynamic balance testing machine which concerns on embodiment of this invention. The figure explaining the problem of the conventional dynamic balance testing machine. The figure explaining operation | movement of the dynamic balance testing machine which concerns on embodiment of this invention. The figure which shows the modification of the dynamic balance testing machine by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Test body 2a, 2b Pickup 3 Motor 4 Pulley 5 Belt 6 Rotary encoder 8 Rotation reference sensor 10 Control device 11 1st counter 12 2nd counter 13 1st comparator 14 2nd comparator 15 Target value setting circuit 16 OR output Circuit W Work

Claims (4)

Drive means for rotationally driving the workpiece;
A reference signal output means for outputting a rotation reference signal each time the workpiece rotates by a predetermined amount;
Pulse signal output means for outputting a pulse signal corresponding to the drive amount of the drive means;
First counter means for counting the pulse signal output from the pulse signal output means, and for resetting the counter in synchronization with the rotation reference signal output from the reference signal output means;
The pulse signal output from the pulse signal output means is counted, and the count value is rewritten to the count value of the first counter means before reset in synchronization with the rotation reference signal output from the reference signal output means. Two counter means;
Determining means for determining whether the count value of the first counter means and the count value of the second counter means match a target count value;
A dynamic balance test comprising: drive control means for decelerating or stopping the rotation of the work by the drive means when it is determined by the determination means that at least one of the count values matches a target count value. Machine. In the dynamic balance testing machine according to claim 1,
The driving means is a belt-type driving device that drives a workpiece via a belt,
The dynamic balance testing machine, wherein the pulse signal output means is a rotary pulse generator around which the belt is wound. In the dynamic balance testing machine according to claim 1 or 2,
The determination means includes
A first comparator for comparing the count value of the first counter means with the target count value;
A second comparator for comparing the count value of the second counter means with the target count value;
An output device for outputting a coincidence signal for operating the drive control means when at least one of the count value of the first counter means and the count value of the second counter means coincides with the target count value; A dynamic balance testing machine characterized by comprising: In the dynamic balance testing machine according to any one of claims 1 to 3,
An unbalance detection means for detecting an unbalance amount and an unbalance angle of the work rotated by the drive means;
The apparatus further comprises target count value setting means for setting the target count value based on the unbalance amount and unbalance angle detected by the unbalance detection means, and signals from the reference signal output means and the pulse signal output means. Dynamic balance testing machine.

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