JP3444248B2 - Dynamic balance testing machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dynamic balance testing machine. 2. Description of the Related Art In a dynamic balance tester, generally, an unbalance signal generated by rotating a specimen is expressed as:
Vibration detection sensors (pickups) respectively arranged on the left and right bearings supporting the specimen at both ends detect the magnitude of the unbalance on both the left and right sides of the specimen from its amplitude value, and attach it to the surface of the specimen. Based on the phase relationship between the rotation reference pulse obtained by detecting the rotation reference position of the mark or the like with a non-contact sensor such as a laser sensor or a photo sensor, and the left and right unbalance signals, the non-uniformity on the left and right sides of the specimen Find the direction (angle) of the balance. In the dynamic balance testing machine as described above, when the vibration detecting sensor is disconnected, its detection output naturally represents the unbalance signal of the test specimen. The magnitude and direction of the unbalance obtained using the output of the vibration detection sensor in such a disconnected state are not those that represent the magnitude and direction of the unbalance actually existing in the test specimen. No. In such a case, a normal test can be restarted by the operator noticing the disconnection of the vibration detection sensor, for example, by replacing the sensor. Since only the calculation result of the magnitude and direction of the balance is displayed, first, it may take time to notice that the dynamic balance test result is abnormal.
Especially, in the case of a fully automatic balancer equipped with a correction machine that automatically performs correction processing based on the measurement result of unbalance, or an automatic correction line, a large number of poorly balanced products may occur. There is. In addition, even if the test result is found to be abnormal, the cause of the abnormality is not necessarily the disconnection of the vibration detection sensor. It can take a considerable amount of time. SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and it is intended to automatically and promptly detect a disconnection of a vibration detection sensor for detecting an unbalanced signal of a specimen and to notify the user of the disconnection. It is an object of the present invention to provide a dynamic balance tester that does not cause a large number of poorly balanced products or the like due to disconnection of a vibration detection sensor in a fully automatic balancer or the like. In order to achieve the above object, a dynamic balance testing machine according to the first aspect of the present invention provides a vibration detection sensor which detects an unbalance signal generated by rotating a test sample. In a dynamic balance tester that determines the magnitude and direction of the unbalance present in the test specimen from the detection result and the rotation reference signal of the test specimen, It is characterized by including a disconnection determination program for determining whether or not the vibration detection sensor is disconnected, and a notification unit for notifying the disconnection based on the determination result. Here, specific examples of the notification means used in the present invention include a mode of displaying on a display, a mode of turning on a lamp or the like, and a mode of playing a buzzer or the like. it can. The present invention utilizes a phenomenon that appears in the output of a vibration detection sensor in a dynamic balance tester when a disconnection occurs and a phenomenon that appears in the result of the balance test as a result. It is to achieve the purpose. That is, when the vibration detection sensor is disconnected,
Normally, the vibration detection output that becomes a sine wave signal synchronized with the number of revolutions of the specimen becomes a signal with a weak amplitude about the noise level, and the magnitude of the unbalance obtained from such vibration detection output is The value becomes extremely small and the state continues. In the invention according to the first aspect, when the vibration detecting sensor is disconnected, the magnitude of the unbalance in the balance test result is reduced several times in succession, and the determination is made by software. When the magnitude of the imbalance in the results of the balance test performed a plurality of times in succession is less than the specified value, it is determined that the vibration detection sensor is disconnected, and the fact is notified. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention. Specimen W
The belt 2 is wrapped around its periphery with its both ends supported by bearings 1 a and 1 b, and is rotated through the belt 2 by the drive of the motor 3. Each bearing 1
a and 1b are supported by the tester frame via springs 4a and 4b so as to be freely displaceable. When the specimen W is rotated, the bearings 1a and 1b vibrate due to the unbalance existing in the specimen W. I do. The vibration of each of these bearings 1a, 1b is detected by a moving coil type vibration detection sensor 5a, 5b.
Is detected by The respective vibration detection sensors 5a, 5b
Are amplified by the amplifiers 11a and 11b as unbalanced signals on the left and right sides of the specimen W, respectively, and then digitized by the A / D converters 12a and 12b. It is captured. A laser sensor 6 is disposed near the surface of the specimen W supported by the bearings 1a and 1b, and the laser sensor 6 detects a mark M attached to the surface of the specimen W. After the detection signal is amplified by the amplifier 14, it is shaped into a pulse signal of a predetermined shape by the pulse shaping circuit 15, and is taken into the arithmetic unit 13 as a rotation reference pulse of the specimen W. The arithmetic unit 13 is a digital arithmetic unit mainly composed of a DSP (Digital Signal Processor), and in addition to the above-mentioned A / D converters 12a and 12b and the pulse shaping circuit 15, calculates an arithmetic result and the like. A display 16 to be displayed and a key switch 17 for giving various commands are connected to each other. Then, the calculation unit 13 calculates the magnitude of the unbalance on each of the left and right surfaces existing in the specimen W from the amplitude values of the unbalance signals from the left and right vibration detection sensors 5a and 5b by a known calculation. The direction (angle) of the unbalance between the left and right surfaces is calculated from the phase relationship between each unbalanced signal and the rotation reference pulse. Then, the calculation results are displayed on the display 16. In addition to the program for calculating the magnitude and direction of the unbalance described above, the calculating unit 13 determines whether or not each of the vibration detection sensors 5a and 5b is disconnected. When it is determined that the sensors 5a and 5b are disconnected, a sensor disconnection diagnosis program for displaying the disconnection on the display 16 is written. FIG. 2 is a flowchart showing the contents of the sensor disconnection diagnosis program. In this example, in a state where the specimen W is mounted on the bearings 1a and 1b and rotated,
The unbalance signal and the rotation reference pulse from each of the vibration detection sensors 5a and 5b are taken in, the magnitude and direction of the unbalance on each of the left and right surfaces of the specimen W are obtained, and the result is displayed on the display 1
After a series of measurement operations shown in FIG. 6, the test results are sequentially stored. Then, among the stored test results, when the results of the latest n times, for example, 5 times, of the imbalance magnitude in each of the left and right surfaces are similar and smaller than a specified value, the corresponding vibration is detected. Sensor 5a,
The display 16 indicates that the wire 5b is disconnected. Therefore, according to the above embodiment, when either of the vibration detection sensors 5a and 5b is disconnected,
Since the operator is immediately notified of the fact, the operator can quickly know the abnormality of the balance test result and its cause. Further, according to this embodiment, since the disconnection of the vibration detection sensors 5a and 5b is determined by software, there is an advantage that no additional hardware is required and it does not become a factor for increasing the cost of the test machine. is there. [0019] [0020] [0021] [0022] [0023] Here, more than in the form of implementation has been notified by the display or the like to that effect when it is judged that there is disconnection of the vibration detection sensors, At the same time as the notification, for example, in a fully automatic balancer or the like, it is possible to stop the system by giving a command to that effect to a sequencer or the like that controls the operation. As described above, according to the present invention, when the vibration detection sensor is disconnected, it is possible to promptly notify the worker of the disconnection. Anomalies in dynamic balance test results and their causes can be known more quickly, especially when applied to fully automatic balancers, etc., to prevent the occurrence of many poorly balanced products due to disconnection of the vibration detection sensor. And its reliability can be improved. [0025] In the present invention, since detecting the disconnection of the vibration detection sensors by the software, there is no need to add a new circuit or the like for the detection, the advantage that not a factor in increase in cost of the apparatus is there.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention according to claim 1; FIG. 2 is a flowchart showing the contents of a sensor disconnection diagnosis program written in a calculation unit 13 in the embodiment of FIG. [Description of Signs] 1a, 1b Bearing 2 Belt 3 Motor 4a, 4b Spring 5a, 5b Vibration detection sensor 6 Laser sensor 11a, 11b Amplifier 12a, 12b A / D converter 13 Operation unit 14 Amplifier 15 Pulse shaping circuit 16 Display 17 key switch

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01M 1/16

Claims (1)

(57) [Claims] [Claim 1] An unbalanced signal generated by rotating a specimen is detected by a vibration detection sensor, and a specimen is detected from a detection result and a rotation reference signal of the specimen. In a dynamic balance tester for determining the magnitude and direction of the unbalance existing in a disconnection determination program for determining whether or not the vibration detection sensor is disconnected using the results of a plurality of continuous tests by the tester. And a notifying means for notifying a disconnection based on a result of the determination.