JP3198527B2 - Vibration indicator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration display.

[0002]

2. Description of the Related Art Vibrating machines, such as vibrating conveyors, vibrating feeders or vibrating parts feeders, are currently widely used in the industrial world. For example, in a car manufacturing plant, a number of vibration feeders and vibration part feeders are provided side by side, and workers periodically measure the amplitude and frequency of the vibrating section to determine whether these vibrators are operating normally. The maintenance is carried out to correct or repair the structure of the drive unit if it is not within the normal range.

However, in order to detect the amplitude of the vibration of these vibrators, a so-called amplitude nameplate 1 as shown in FIG. 10 is currently used. This is made of a rectangular mount 2, on which graduation lines 3 are printed in parallel at a constant pitch. V-shaped display lines 4a, 4b intersecting these
Is printed. A film for protecting the adhesive film is attached to the back side of the backing paper 2 of the nameplate 1. The film is peeled off and attached to the vibration surface of the vibrator V whose amplitude is to be measured as shown in the figure. As shown in FIG. 11, the amplitude display lines 4a, 4b
Are strips P and Q having a width proportional to the amplitude as an afterimage. As a result, the tip of the overlapped portion 5 of these bands becomes the scale line 3
The amplitude of the vibrator V is visually detected depending on the position of the vibrator V. However, in order to accurately measure the amplitude, it is necessary to attach the scale line 3 in parallel with the vibration direction a of the vibrator V as shown in FIG. Even if it is worn, there is a reading error by each worker. Further, even if the same worker is used, a reading error occurs due to the brightness or the like at that time. This error varies depending on the operator, but may be about ± 10%.

As for the vibration frequency, a vibrating frequency meter having a large number of leads arranged thereon is applied to a part of the vibrator. At this time, the lead resonating with the vibration is observed, and the vibrating frequency is displayed by the frequency corresponding to the lead. The vibration frequency is read, but it is not very accurate, depending on the number of leads.In addition, not only one lead resonates and swings greatly, but the leads before and after it are slightly smaller, May swing in size. At this time, the vibration frequency is calculated based on the ratio of these vibration magnitudes, but the personal error is large.

In view of the above-mentioned problems, the applicant of the present invention has previously made it possible to easily and reliably perform maintenance by accurately detecting the amplitude and frequency of a large number of vibrators in a short time. For the purpose of providing at least a microcomputer, a battery, and a display element connected to an output terminal of the microcomputer, the output of the display element is received on a front panel portion of a casing, and at least the amplitude and / or A main body having a display unit for digitally displaying the vibration frequency, a vibration acceleration detector detachable from a part of the vibration object to be measured, and a detection force of the vibration acceleration detector, and a connector part of the main body. Fuhaba及the detection Todoroki of the vibration acceleration detector mounted on a portion of the measured vibrator composed of a conductive cord connected to the object to be measured vibrator as the operation result of the microcomputer / Or the vibration frequency has proposed a portable vibration indicator is characterized in that so as to be displayed on the display unit in a digital value (Jitsugantaira 2-59283
issue).

In this vibration display, when the vibrating body to be measured is operated, the amplitude and the vibration frequency are calculated by the microcomputer based on the detected force from the vibration acceleration detector, and as a result, the amplitude of the vibrating body to be measured is obtained. And the value of the vibration frequency are displayed on the display unit as digital values. Since the amplitude value and vibration frequency on the display are digital values, there is no individual difference in reading,
The amplitude and frequency can be measured immediately and accurately. Since the casing is portable and has a built-in battery, it is easy to handle and can be easily moved to any place to measure the amplitude and frequency of vibration of each vibrator immediately and easily.

[0007] In the above display, the amplitude is displayed on the display unit in digital value. However, the one disclosed in the embodiment is switched by a conveyor and a feeder to switch the switch. Built-in analog /
The digital converter is used in the full range, and the amplitude is displayed digitally as accurately as in both the low frequency range and the high frequency range. That is, for example, 50H in the feeder
While it is driven by z, a conveyor (generally driven by an electric motor, a crank mechanism, etc.) has a drive frequency of about 550 RPM, and there is a large difference in drive frequency.
In the above-described embodiment, the switches are switched according to the object to be measured of this model, and are switched between the conveyor driven by driving in the low frequency region and the feeder driven in the high frequency region. Therefore, these amplitudes are each digitally measured with the same precision.However, depending on the skill of the operator, this switching may be forgotten, and it cannot be recognized whether the feeder or the conveyor is used. The changeover switch cannot be used effectively for the user.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has the same accuracy regardless of the skill level of the operator, regardless of the driving frequency of the vibrating body to be measured. Accordingly, it is an object of the present invention to provide a vibration indicator capable of detecting the amplitude of the vibrating body.

[0009]

The object of the present invention is to provide a vibration conveyor or a part of a vibration feeder which is detachable.
A vibration acceleration detector and a detection output of the vibration acceleration detector.
And increasing the width device for Zohaba, analog receiving an output of bulking width unit /
A digital converter, a microcomputer for receiving the output of the converter, and a display element connected to an output terminal of the microcomputer are built in, and the output of the display element is received on the front panel, and at least the amplitude is digitally displayed. The vibration conveyor or a part of the vibration feeder, comprising a main body provided with a display unit to derive a detection output of the vibration acceleration detector and a conductive cord connected to a connector part of the main body. Amplifier to increase the detection output of vibration acceleration detector
A vibration display of the vibration conveyor or the vibration feeder as a calculation result from the output of the microcomputer as a digital value on the display unit, wherein the microcomputer controls the frequency of the output of the analog / digital converter. A control signal for adjusting the gain of the amplifier to small or large according to whether the signal is large or small is supplied to the amplifier so that a fixed number of bits of the analog / digital converter is effectively used. This is achieved by a vibration indicator, which is characterized by being used.

[0010]

[Function] Whether measuring the amplitude of a conveyor in the low frequency range or the amplitude of the electromagnetic vibration feeder in the high frequency range, the microcomputer detects the vibration frequency and controls the gain of the amplifier accordingly. I do. Therefore, even if the conversion of the analog / digital converter is constant, the amplitude can always be measured with the same accuracy. It is not necessary for the measurer to switch the switch depending on the driving frequency range.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A portable vibration display according to an embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show front views of the portable vibration display device of the first embodiment. In the drawings, the portable vibration display device is generally indicated by 10 and has a substantially rectangular shape. As shown in FIG. 4, the casing 11 includes a liquid crystal display device 14 and a battery 17. The battery 17 is stably supported via a mounting portion 18. The microcomputer and the above-mentioned liquid crystal display device 14 and the like are mounted on the chassis 13 with mounting screws 15
Thus, it is held at a predetermined position in the casing 11.
A power switch 19 is provided on the left side of the front panel section 12. This is a known double push switch. The battery switch 17 supplies power to each section when pressed once, and the power supply when further pressed. It is designed to shut off. To the right of this is a lamp 2 which is turned on when the power switch 19 is turned on.
0 is provided, which indicates that the power of the built-in battery 17 is supplied to each unit. Further, a display section 21 is provided below these, and in this embodiment, the display section 21 includes a width display section 22a and a vibration frequency display section 22b which are arranged side by side in the horizontal direction. Therefore, as will be described later, the microcomputer calculates the detection force from the vibration acceleration detector, and the resulting digital value drives the liquid crystal display device 14 with the driver output as the output of the microcomputer. This display part 2
In 2a and 22b, the amplitude and the vibration frequency are displayed as digital values, for example, as shown in the figure. Above the amplitude display portion 22a, (mm) indicating the unit of the amplitude is stamped out of the liquid crystal portion, and the vibration frequency is displayed as a digital value on the vibration frequency display portion 22b. Above this, in the liquid crystal unit, according to the present embodiment, the unit is vpm or Hz.
, So that they can be selectively displayed.

An operation mode changeover switch 28 is provided below the display section 21.
That is, when switched to the continuous operation side, the frequency and the amplitude are displayed from time to time when the vibration object to be measured is performing the continuous operation. When the knob 29 of the operation mode changeover switch 28 is switched to a single (SINGLE) mode below as shown by a dashed line, the trigger switch 31 below this is pressed at the time of starting or stopping the operation to drive the vibrator. The force starts to be supplied or is cut off, but the vibration until it reaches a steady state or until it stops performs resonance free vibration, so this frequency is detected by the vibration acceleration detector. Then, the frequency is calculated by a microcomputer and this frequency is displayed on the vibration frequency display section 22b as a digital value. Therefore, the resonance frequency of the vibrating body to be measured can be detected. A function changeover switch 32 is further provided below the front panel section 12. This is a rotary switch. When the pointer 34 is turned to the position A, B, C or D by rotating the knob 33, each mode can be performed. For example, at the position A shown in the figure, a normal measurement state can be obtained. That is, the amplitude and the vibration frequency of the vibration object to be measured can be displayed on the display unit 21. The pointer 34 is also provided by the knob 33.
Is switched to the position B, the portable vibration display 10 operates as a transmitter for personal computer communication, and the amplitude and vibration frequency as digital values on the display unit 21 are displayed on a personal computer disposed near the portable vibration display. You can send it. In C and D, this is further multi-functionalized.

As shown in FIG. 4, the casing 11 is further provided with trimmer resistance adjusters 35 and 36, one for adjusting the amplitude of the feeder and the other for adjusting the amplitude of the conveyor. Thereby, the analog input of the A / D converter in the circuit diagram of FIG. 5 is also manually adjusted.

Next, an electric circuit incorporated in the portable vibration display 10 will be described with reference to FIG. In FIG. 5, the vibration acceleration detector 40 has a shape as shown in FIG. 7, and as will be described later, this detection force is supplied to a low-pass filter 41, where a high cycle of noise or the like is generated. The signal component is removed, and this output is supplied to the amplifier 42. The output amplified here is supplied to an A / D converter 43 to convert an analog value into a digital value, and this digital value is supplied to a microcomputer 45. A switch section 46 is further connected to the input terminal side of the microcomputer 45. The switch section 46 includes various switches 28 and 31 shown in FIG.
32 are collectively shown, and the output obtained by switching these is supplied to the microcomputer 45. The microcomputer 45 receives the digital output from the A / D converter 43 and the changeover switch signal of the switch unit 46, performs a predetermined operation, and supplies the operation result to the liquid crystal display unit 47. This includes the liquid crystal display device 14 shown in FIG. Further, it is assumed that a driving circuit thereof and a liquid crystal unit as the display unit 21 as shown in FIG. 1 are also included. For example, the output terminal of the microcomputer 45 performs the mode switching of the operation mode changeover switch 28 shown in FIG.
, Which sends a signal to the personal computer 48. Although automatic voltage regulator 49 is indicated by a dashed line, if the automatic voltage regulator when also switching the function selector switch 32 for example, C position, the automatic voltage by the detection Todoroki vibration acceleration detector of this time The adjusting unit of the adjuster can be automatically driven to automatically adjust to a desired amplitude and frequency. Although not shown in FIG. 5, various devices are connected to the output side so as to perform the same function by switching the function changeover switch 32 in FIG.

[0016] Then the vibration acceleration detector with reference to FIG 40
Will be described in detail. It has a substantially cylindrical casing 50 in which a force detecting element 51 made of, for example, lead zircon san is held on a mounting plate 52. The flange portion of the casing 50 is fixed to the mounting plate 52 by, for example, screwing. The force detecting element 51 is adapted to guide the detected force through a lead wire 53. A vibration display line 55 is engraved on the upper surface of the casing 50. This is casing 5
0 is engraved so as to be parallel to and in the same direction as the force detection direction F of the built-in force detection element 51. It is also assumed that a flat magnet is mounted on the back surface of the mounting plate 52. Therefore, the whole vibration acceleration detector 40 can be easily attached to and detached from the vibrating body by the magnet.

In FIG. 5, the A / D converter 43 is connected to the terminal of a trimmer resistance device 44 composed of trimmer resistance adjusters 35 and 36 shown in FIG.
The manual adjustment of the analog input in the D converter 43 can be performed. The microcomputer 45 includes an A / D converter 43 in the gain control section g of the amplifier 42.
, And receives a gain control signal for changing the gain of the amplifier 42 in accordance with the output frequency in order to effectively use a fixed number of bits.

The portable vibration display 10 according to the first embodiment of the present invention is constructed as described above. Next, this operation will be described.

FIG. 7 shows a vibration acceleration detector 40 according to the present invention.
Next, the mounting operation to the vibrator will be described. In this embodiment, the vibration feeder 6 shown in FIG.
It is assumed that zero vibration is measured. As is well known, the vibration feeder 60 includes a trough 61 having a U-shaped cross section and a drive unit 62 for transmitting a vibration force to the trough 61. The drive unit 62 is configured by a leaf spring, an electromagnet, or the like. Vibration feeder 6
0 is entirely suspended from a part of the building by the coil springs 63a and 63b. When a commercial power supply is applied to the coil of the electromagnet of the drive unit 62, the coil vibrates at 50 Hz, for example, at about 2 mm in the direction indicated by the arrow m. Vibration acceleration detector 4 shown in FIG.
When the mounting plate 52 is applied to the side surface of the trough 61,
It is easily fixed to the side surface of the trough 61 by a magnet attached to the back surface. The vibration acceleration detector 40 also vibrates together with the trough 61.
A vibration display line 55 is engraved on the upper surface of 0. In the first mounting, the mounting is performed so as to be parallel to the expected vibration direction m. However, if the vibration display line 55 is sufficiently thin and exactly coincides with the vibration direction, the thickness of the vibration display line 55 is substantially the same as the thickness of the line at rest. However, if it is tilted in any direction, it will remain on the retina of the eye as an afterimage, so that it can be seen with a certain width or a tilted width. Therefore, while observing this, the mounting direction is adjusted while the casing 50 is pinched so as to be approximately equal to the thickness of the vibration display line 55 at rest. When the magnet is fixed to the side surface of the trough 61 at a predetermined angle by a magnet, the force detection direction 51 of the force detection element 51 made of lead zirconate in the casing 50 is parallel to and coincides with the direction of the force detection. Can be measured. This vibration detecting force, that is, the voltage is supplied to the low-pass filter 41 shown in FIG.

In the function switch 32, a pointer 34
Are switched to face A. The detected force from the vibration acceleration detector 40 is supplied to a low-pass filter 41, which contains not only an ideal sine waveform but also a large amount of noise in a ripple form as shown by a waveform S. As a result, the ripple-like noise is removed as a high frequency component as shown on the output side, and the signal S ′ of the low frequency component is supplied to the amplifier 42.
Here, the signal is amplified to a predetermined size and supplied to the A / D converter 43. That is, as described above, the vibration feeder 60 vibrates at about 50 Hz at about 2 mm.
In this type of feeder, the acceleration is about 15 to 30 g, and the maximum value determines the analog input of the A / D converter so that it becomes a full-scale digital value.
That is, the gain of the amplifier 42 is automatically adjusted according to the output frequency supplied to the microcomputer 45. Therefore, the amplitude can be accurately detected in accordance with the number of bits of the A / D converter 43. A clock pulse generator is provided in the microcomputer 45 in a known manner. The clock pulse has a predetermined number of pulses and does not fluctuate with time and has high accuracy.
The vibration frequency of the output of the D converter 43 is detected.

The output of the microcomputer 45 is an LCD (Liquid)
d Crystal Display) LCD 47
Supplied to That is, the amplitude and the vibration frequency of the vibration feeder 60 calculated by the microcomputer 45 are represented by digital values as shown in FIG.
Are displayed on the display unit 21 as shown by. That is, it can be seen that the amplitude of the vibration feeder 60 during the measurement is 1.25 mm and the vibration frequency is 50.25 Hz. Conventionally, an amplitude nameplate 1 as shown in FIGS. 10 and 11 is attached to the side surface of the trough 61 such that the scale line 3 coincides with the vibration direction, and the afterimage of the amplitude display lines 4a and 4b by the retina of the eye is displayed. The operator has read this intersection using the information, but as described above, there is an individual difference and the intersection changes depending on the surrounding conditions.
According to the present embodiment, the amplitude and the vibration frequency are displayed as digital values as shown in FIG. 2, so that the measurement can be performed accurately and unified without any personal error.

[0022] Since the vibrating feeder as shown in FIG. 6 is a plant is operated in parallel number is a normal, also vibration acceleration detected in the same manner to another of the vibration feeder 60 so carried out simultaneously in the maintenance Immediately after the container 40 is attached, the amplitude and vibration frequency of the vibration feeder can be accurately detected and read.

The amplifier 42 has a gain control unit g.
The microcomputer 45 receives the output of the A / D converter 43 and controls the gain of the amplifier 42 according to the output frequency. That is, the control signal is supplied to the gain control unit g. Therefore A / D
Although the number of bits of the converter is constant, the accuracy is greatly different when the gain is constant between when the detected acceleration is low and when the detected acceleration is high. , The gain of the amplifier 42 is increased. Therefore, the measurement can be performed with the same accuracy regardless of whether the analog input to the amplifier 42, that is, the detection power is large or small.

In this embodiment, the amplitude is measured with higher accuracy than the conventional one as follows. That is, as shown in FIG. 8, the output of the vibration acceleration detector 40 has a sinusoidal waveform S as a whole, but contains noise, and large noises P and P ′ are often present for some reason. When the amplitude is calculated by performing double integration on such an output S, since the amplitude is measured from the maximum value and the minimum value by double integration, a large noise as shown in FIG. When P and P 'are generated, the amplitude is measured to be larger than the actual amplitude. If it is an ideal sine waveform without such a noise, there is no problem and accurate measurement can be performed. Generally, however, noises of various sizes are included as shown in FIG. According to the method of the present embodiment, this effect can be eliminated.

That is, assuming that the amplitude to be measured is At, the displacement X at each time is X = Atsin ωt / 2, which is differentiated twice, and [the second derivative of X] = − Atω ² si
nωt / 2.

In this embodiment, the acceleration RMS M.
S. (Root Mean Square), that is, calculate the effective value. That is, the acceleration at each moment is integrated over time, divided by the time during this time, and the average value is taken. Therefore, [the second derivative of X] r. m. s. =
At ω ² / (2√2). When this is expressed in g, Gr.
m. s. = Atω ² / (2√2g) (g = 9800). Therefore, the amplitude At = 2√2Gr. m. s.
g / ω ² , that is, the second derivative of X is measured at each instant, and the amplitude At is calculated by taking a temporal average value of the measured values. Therefore, even if large noises P and P ′ as shown in FIG. 8 occur in a short time by taking an average value at a certain time, this effect can be almost ignored.

Next, a case where the vibration of the vibration conveyor is measured will be described. This is generally connected by a leaf spring inclined in a predetermined direction between a long trough and a base block disposed in parallel below the trough. The crank drive drives the trough in a direction substantially perpendicular to the longitudinal direction of the leaf spring. Vibration is performed at a frequency of, for example, 552 r. p. m. And much lower than the vibrating feeder. But the amplitude is 12.
Although it is as large as 8 mm, the acceleration is proportional to the square of the frequency and proportional to the amplitude, so that the acceleration is much smaller than that of the vibration feeder. Generally, the vibration conveyor acceleration is 1
g to about 5 g. Therefore, the output detected by the force detecting element 51 in the vibration acceleration detector 40, that is, the voltage per 1 mm of the amplitude becomes low. However, according to the present embodiment, even in such a case, it is possible to perform measurement with the same high accuracy as a vibration feeder by effectively using a fixed number of bits of the A / D converter 43 by controlling the gain of the amplifier 42. Although not shown, the vibration acceleration detector 40 is fixed to the side surface of the trough of the conveyor in the same manner as in the case of the vibration feeder. Thereby, as shown in FIG. 1, the amplitude was 12.8 mm and the frequency was 552.0 r. p. m. Is displayed as a digital value. Since the amplitude is the same unit, mm
However, in the case of a conveyor, the display is switched from Hz to VPM on the display unit 22b since the unit is VPM.

Next, a method for measuring the resonance frequency of a vibrator, for example, the vibration feeder 60 will be described. In this case, the knob 29 can be switched to the single (SINGLE) mode by the operation mode changeover switch 28 as shown in FIG. In this state, the power supply to the drive unit 62 of the vibration feeder 60 is cut off. By pressing the trigger switch 31 simultaneously with or immediately after the cutoff, the resonance frequency of the vibration feeder 60 is digitally displayed on the vibration frequency display section 22b as 52.5 Hz.

When the power supply to the drive unit 62 of the vibration feeder 60 is cut off, the displacement of the trough 61 does not become zero immediately from the vibration shown in FIG. 8 but becomes zero through a transient phenomenon as shown in FIG. This is because the amplitude decreases exponentially, but attenuates due to free vibration because the driving force has already been cut off. This free vibration has a resonance frequency as apparent from vibration engineering. Therefore Fuhaba From this point exponentially decreases assuming that the power is turned off by switching off now time t _1. And When pressing the trigger switch 31 at time t _2, calculate the number of waves in the microcomputer during future time T, as compared with the clock pulses built now microcomputer, read this number, thus per unit time The number of waves, that is, the resonance frequency is calculated. This is 52.5 Hz in the vibration frequency display section 22b shown in FIG. Thus, for example, in this type of resonance type vibrator, the weight of the trough and the spring constant of the leaf spring are set so that the resonance frequency is close to the drive frequency in order to obtain a large amplitude with a small drive force. However, when the resonance frequency detected by this method is largely changed, for example, when the driving frequency is set to 50 Hz 70
When a resonance frequency such as 30 Hz or 30 Hz is read, it is considered that a trouble has occurred in any part of the vibration feeder 60. For example, a broken portion of the leaf spring, a sliding of a weight adjusting block, or the like can be considered. In the measurement of the resonance frequency, the vibration shown in FIG.
For example, by sequentially attaching the acceleration detectors 40 to, for example, a number of vibrators arranged side by side, it is possible to immediately and surely detect the acceleration detectors, thereby making maintenance much easier than before.

Next, an electric circuit incorporated in the portable vibration display according to the second embodiment of the present invention will be described with reference to FIG. The appearance of the display is the same as that of the first embodiment. In FIG. 12, the vibration acceleration detector 40 'has a shape as shown in FIG. 13, and as will be described later, includes detection elements 40a and 40b, and their detection outputs are low-pass filters 41a and 41b, respectively. , Where high cycle signal components such as noise are removed, and this output is supplied to amplifiers 42a and 42b. The output amplified here is supplied to A / D converters 43a and 43b.
Is converted into a digital value, and the digital value is supplied to the microcomputer 45. A switch section 46 is further connected to the input terminal side of the microcomputer 45, which collectively shows various switches 28, 31, 32, etc. shown in FIG. It is supplied to. The microcomputer 45 receives the digital outputs from the A / D converters 43a and 43b and the switch signal of the switch unit 46 and performs a predetermined operation.
7 is supplied. This includes the liquid crystal display device 14 shown in FIG. Further, it is assumed that a driving circuit thereof and a liquid crystal unit as the display unit 21 as shown in FIG. 1 are also included. The output terminal of the microcomputer 45 is further supposed to perform the personal computer communication at the position B, for example, by mode switching of the operation mode changeover switch 28 shown in FIG. 1, but the output terminal for the output thereof is indicated by d. This sends a signal to the personal computer 48. Although automatic voltage regulator 49 is indicated by a dashed line, if the automatic voltage regulator when also switching the function selector switch 32 for example, C position, the automatic voltage by the detection Todoroki vibration acceleration detector of this time The adjusting unit of the adjuster can be automatically driven to automatically adjust to a desired amplitude and frequency. Although not shown in FIG. 12, it is assumed that various devices are connected to the output side so as to perform the same function by switching the function changeover switch 32 in FIG.

[0031] Referring now to FIG. 13 vibration acceleration detector 4
Details of 0 'will be described. It has a substantially cylindrical casing 50 in which first and second force detecting elements 40a, 40b made of, for example, lead zirconate are held on a mounting plate 52. The flange portion of the casing 50 is fixed to the mounting plate 52 by, for example, screwing. The force detection elements 40a and 40b are configured such that their detected forces are led out through conductors 53a and 53b. First According to the present invention, the second force sensing element 40a, a force detection direction F _1, F ₂ and 40b are perpendicular to each other. It is also assumed that a flat magnet is mounted on the back surface of the mounting plate 52. Therefore, the entire vibration acceleration detector 40 can be easily attached to and detached from the vibrating body by the magnet.

In FIG. 12, the A / D converter 43
The terminals of a trimmer resistance device 44 composed of trimmer resistance adjusters 35 and 36 shown in FIG. 4 are connected to the terminals a and 43b so that the analog input in the A / D converters 43a and 43b can be manually adjusted. I have. Also, the gain control units g ₁ and g _{2 of the} amplifiers 42a and 42b
Microcomputer 45 includes A / D converters 43a and 43b
Of the amplifiers 42a, 4a, and 4a according to the output frequency in order to use a fixed number of bits effectively.
A gain control signal for changing the gain of 2b is received.

Further, according to the present embodiment, A
The amplitude components in the X and Y directions are calculated from the outputs A and B of the / D converters 43a and 43b by a method described later. These amplitude components, XAt and YA
The square root of (XAt ² + YAt ² ) is calculated by t, and this is displayed on the amplitude display section 22a as the amplitude value of the vibrating body to be measured.

Further, according to this embodiment, the amplitude obtained as described above, the square root of (XAt ² + YAt ² ) and XA
The vibration angle of the vibration body to be measured in the X direction or the Y direction can be calculated by a trigonometric function with t or YAt. This is not shown in FIG. 1, but, for example, when the resonance frequency is displayed on the frequency display unit 24 in FIG. 3, the vibration angle may be displayed on the amplitude display unit 22 a. Alternatively, although not shown in FIGS. 1 to 3, a vibration angle display unit may be provided.

The portable vibration display according to the first embodiment of the present invention is constructed as described above. Next, this operation will be described.

FIG. 13 shows a vibration acceleration detector 40 'according to the present embodiment. First, an operation of attaching the vibration acceleration detector to the vibrator will be described. Also in this embodiment, the vibration of the vibration feeder 60 as shown in FIG. 6 is measured. When the mounting plate 52 of the vibration acceleration detector 40 ′ shown in FIG. 13 is applied to the side surface of the trough 61, the vibration acceleration detector 40 ′ is easily fixed to the side surface of the trough 61 by a magnet mounted on the back surface thereof. The vibration acceleration detector 40 'vibrates together with the trough 61, but according to the present embodiment, the mounting angle is arbitrary.
Conventionally, a vibration display line is engraved on the upper surface of the casing 50, and in the first installation, the vibration display line is attached so as to be parallel to the expected vibration direction m, but the vibration display line is sufficiently thin and accurately vibrated. If it matches the direction, it is almost the same as the thickness of the line at rest, but if it is tilted in any direction, it will remain as an afterimage on the retina of the eye, and it will be visually observed with a certain width or an inclined width. Therefore, while observing this, the mounting direction is adjusted while the casing 50 is pinched so as to be approximately the thickness of the vibration display line at rest, but according to the present invention, such mounting adjustment is not required at all. . When fixed to the side surface of the trough 61 by the magnet, linear vibration occurs in a plane parallel to the force detection directions F ₁ and F _{2 of the} force detection elements 40 a and 40 _{b made of} lead zirconate in the casing 50. Therefore, the vibration of each direction component can be measured. The respective vibration detection forces a and b, that is, the voltages are applied to the conductors 53a and 53b.
Through the low-pass filters 41a and 41b shown in FIG.
Supplied to In the operation mode switch 28, the knob 29 is switched to the continuous mode, that is, to the CONT side. In the function switch 32, the pointer 3
4 has been switched to face A. It is the electrical circuit as shown in Figure 12 is provided in its main body in the state as described above, but the vibration acceleration detector 40 '
Are supplied to low-pass filters 41a and 41b, which contain not only an ideal sine waveform as shown by waveforms a and b but also a large amount of noise in the form of ripples, and these low-pass filters 41a and 41b By passing
As shown on the output side, the ripple noise is removed as a high frequency component, and the low frequency component signals Sa and Sb are supplied to the amplifiers 42a and 42b. Here, the signal is amplified to a predetermined size and supplied to the A / D converters 43a and 43b. The vibration feeder 60 is, for example, 50 Hz as described above.
In this kind of feeder, the acceleration is about 15 to 30 g, and the maximum value is A
The analog input of the / D converter is determined so as to be a full-scale digital value. Therefore, the amplitude can be accurately detected in accordance with the number of bits. A clock pulse generator is provided in the microcomputer 45 in a known manner. The clock pulse has a predetermined number of pulses and does not fluctuate with time and has high accuracy. , 4
The vibration frequency of the output of 3b is detected.

The output of the microcomputer 45 is an LCD (Liquid)
d Crystal Display) LCD 47
Supplied to That is, the amplitude and the vibration frequency of the vibration feeder 60 calculated by the microcomputer 45 are represented by digital values as shown in FIG.
Are displayed on the display unit 21 as shown by. That is, it can be seen that the amplitude of the vibration feeder 60 during the measurement is 1.25 mm and the vibration frequency is 50.25 Hz.

[0038] Since the vibrating feeder as shown in FIG. 6 is a plant is operated in parallel number is a normal, also vibration acceleration detected in the same manner to another of the vibration feeder 60 so carried out simultaneously in the maintenance Immediately after the container 40 is attached, the amplitude and vibration frequency of the vibration feeder can be accurately detected and read.

According to the present invention, the amplifiers 42a and 42b are provided with gain control sections g ₁ and g ₂ , which receive the output frequencies of the A / D converters 43a and 43b to which the microcomputer 45 is supplied. The gains of the amplifiers 42a and 42b are controlled in accordance with the output. That is, although the number of bits of the A / D converter is constant, the accuracy is greatly different between when the detected acceleration is low and when the detected acceleration is high. In order to make this match, the microcomputer 45 uses the amplifier 42a, The gain of 42b is increased. Therefore, the measurement can be performed with the same accuracy regardless of whether the analog input of the gain control unit, that is, the detection force is large or small.

Also in this embodiment, the amplitude is measured with higher accuracy than in the prior art, as in the first embodiment.

As described above, according to this embodiment, the vibration
The mounting position of the acceleration detector 40 on the vibrating body may be arbitrarily determined.
This will be described with reference to FIG.

In FIG. 14, the above-described force detecting element 40
The detection directions of a and 40b are set to the y direction and the x direction, respectively.
These indicate rectangular coordinates, but if the vibration direction of the trough is V as shown in FIG. 15 at a certain mounting position on a certain trough, the amplitude component y ₀ and the force detecting element square root of it Fuhaba components x ₀ of 40b is that obtained as described above now ^{_{(x 0 2 + y 0 2}} ) is calculated, which is displayed on Fuhaba display unit as a digital value. Force detecting elements 40a in a case attached to the position of Matabetsu, y 'direction, x' as the detection direction 40b shown in FIG. 15 as direction, Fuhaba component y ₀ 'in each direction with respect to the same vibration, x ₀ ′ are obtained and from these (x ₀ ′ ²
+ Y ₀ ′ ² ) is calculated, which is equal to the square root of (x ₀ ² + y ₀ ² ) as is apparent from the illustration of FIG.
It can be seen that the same amplitude is measured for the same vibration at other mounting angle positions.

The case where the vibration of the vibration conveyor is measured is the same as in the first embodiment, and a description thereof will be omitted.

Although the embodiments of the present invention have been described above, the present invention is of course not limited to these embodiments, and various modifications can be made based on the technical concept of the present invention.

For example, in the above embodiment, the gain of the amplifier is varied in accordance with the frequency of the output received by the microcomputer 45 from the analog / digital converter, but this is compared with a predetermined frequency set by the microcomputer 45. The amplifier gain may be switched in two stages depending on whether the gain is larger or smaller. Alternatively, by setting the number of steps to a plurality of types of predetermined frequencies set in the microcomputer according to the frequency range to be measured, and determining the range in which the measurement frequency is determined by these,
The amplifier gain may be changed.

[0046]

According to the vibration indicator of the present invention, the measurer even in a high frequency range in the low frequency region is not required to be any recognition of this, that is, whether the vibration conveyor or vibrating feeder table
Analog without the need to switch indicators
Effectively use a certain number of bits of the analog / digital converter,
The amplitude can always be measured accurately and accurately .

[Brief description of the drawings]

FIG. 1 is a front view of a portable vibration display according to a first embodiment of the present invention.

FIG. 2 is a similar front view for explaining the operation of the portable vibration display.

FIG. 3 is a similar front view for explaining the operation of the portable vibration display.

FIG. 4 is a side view of the portable vibration display.

FIG. 5 is a block diagram of an electric circuit built in the display.

FIG. 6 is a side view of a vibration feeder as an example of a vibrator measured by the portable vibration display device of the present embodiment.

FIG. 7 is a perspective view of a vibration acceleration detector in the portable vibration display.

8 is a detection output waveform of a vibration acceleration detector attached to the vibration of the vibrator to be measured shown in FIG.

FIG. 9 is a waveform diagram showing a transient phenomenon of the output of the detector when the power supply of the drive unit of the vibrator is cut off.

FIG. 10 is a front view of a conventional amplitude nameplate for reading an amplitude.

FIG. 11 is a side view for explaining the same operation.

FIG. 12 is a block diagram of an electric circuit built in the vibration indicator of the second embodiment.

FIG. 13 is a perspective view of a vibration acceleration detector in the portable vibration display device.

FIG. 14 is a schematic front view for explaining the operation of the vibration acceleration detector.

FIG. 15 is a graph for explaining the same operation.

[Explanation of symbols]

40 vibration acceleration detector 40 'vibration acceleration detector 40a force detection element 40b force detection element 42 amplifier 42a amplifier 42b amplifier 45 microcomputer 51 force detection element g gain control section g ₁ gain control section g ₂ gain control section

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) G01H 17/00 G01M 19/00 G01D 3/024

Claims (6)

(57) [Claims] At least a vibration conveyor or a vibration fee
Vibration acceleration detector that can be attached to and detached from a part of the
Amplifier for increasing the detection output of the degree detector, an analog / digital converter receiving the output of the amplifier, a microcomputer receiving the output of the converter, and a display connected to the output terminal of the microcomputer incorporates a device, receiving an output of the display element on the front panel portion, a body having a display unit for displaying at least Fuhaba digitally, derives the detection output of the vibration acceleration detector, the body connector And a detection output of the vibration acceleration detector attached to a part of the vibration conveyor or the vibration feeder.
In the vibration display device, the amplitude of the vibration conveyor or the vibration feeder is displayed as a digital value on the display unit as an operation result of the microcomputer from the output of the amplifier for increasing the amplitude of the analog signal. A control signal for adjusting the gain of the amplifier to small or large according to whether the frequency of the output of the digital converter is large or small is supplied to the amplifier. A vibration indicator characterized by using a fixed number of bits effectively. 2. The detection output of the vibration acceleration detector is increased.
2. The vibration display according to claim 1, wherein the microcomputer calculates the amplitude of the vibration conveyor or the vibration feeder from the effective value of the acceleration based on the output of the amplifier. 3. The vibration acceleration detector includes an acceleration detection element and mounting means for supporting the acceleration detection element, wherein the mounting means is detachable from the vibration conveyor or a part of the vibration feeder, and is always mounted. 2. The device according to claim 1, wherein the portion is attachable to the part in parallel to an acceleration detecting direction of the acceleration detecting element.
Or the vibration indicator according to 2. 4. A mode change switch is provided on the main body,
4. The vibration display according to claim 1, wherein at least the display value of the display unit can be transmitted to a personal computer by the switching. 5. The vibration indicator according to claim 3, wherein said attachment means is a magnet. 6. The vibration acceleration detector includes a first acceleration detection element, a second acceleration detection element so as to have a detection direction perpendicular to a detection direction of the first acceleration detection element, and a second acceleration detection element. The first and second planes are supported on a plane parallel to the vibration direction of a part of the vibration conveyor or the vibration feeder.
Output means a and b of the amplifier for amplifying the detection output of the first and second acceleration detecting elements.
The vibration display according to any one of claims 1 to 5, wherein a square root of (a ² + b ² ) is calculated from the following formula, and the amplitude of the vibration conveyor or the vibration feeder is measured from the result.