JP2953055B2 - How to measure amplitude - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for measuring an amplitude.

[Conventional technology and its problems]

Vibrating machines, such as vibrating conveyors, vibrating feeders or vibrating parts feeders, are currently widely used in industry. For example, in a car manufacturing factory, many vibration feeders and reading parts feeders are installed side by side, and workers regularly measure whether the vibrator is operating normally by measuring the amplitude of the vibrating part. Recognition is performed and maintenance is performed to repair or repair the structure of the drive unit if it is not within the normal range.

However, in order to detect the amplitude of vibration of these vibrators, a so-called amplitude nameplate (1) as shown in FIG. 6 is currently used. It consists of a rectangular backing (2), on which graduation lines (3) are printed in parallel at equal pitch. A V-shaped display line intersecting them (4a)
(4b) is printed. A film for protecting the adhesive film is attached to the back side of the backing paper (2) of the nameplate (1). This film is peeled off, and as shown in FIG. After pasting, as shown in FIG. 7, the amplitude display lines (4a) and (4b) are formed as strips P and Q having a width proportional to the amplitude as afterimages. Accordingly, the amplitude of the vibrator V is visually detected based on which of the scale line (3) the leading end of the overlapped portion (5) of these bands extends. However, in order to accurately measure the amplitude, the scale line (3) must be adhered so that the scale line (3) is parallel to the vibration direction a of the vibrator V as shown in FIG. Even if they are attached in parallel, 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%.

On the other hand, FIG. 8 shows a conventional vibration detector (1 '). In this cylindrical casing (2'), lead zirconate (piezoelectric element) as a force detecting element or an acceleration detecting element is provided. The acceleration detection direction is the direction indicated by the arrow a. A mounting plate (3 ') is integrally fixed to the casing (2'), and a lead wire (10 ') is led out from lead zirconate. When measuring, for example, the amplitude of the vibrating body (4 ') using such a vibration detector (1'), the vibration detector is set so as to be parallel to the vibration direction b of the vibrating body (4 '). (1 ') must be attached to a part of the vibrating body (4') by the attaching portion (3 '), and the attaching surface of the attaching portion (3') is attached to the vibrating body (4 ').
There is no problem as long as the vibration feeder (5 ') is flush with a part of the surface and the direction perpendicular to this surface is perpendicular to the detection direction of the force detecting element. For example, as shown in FIG.
If you want to measure the amplitude, you must install as follows. First, the vibrating feeder (5 ') is well known, but will be described. The trough (6') has a U-shaped cross section. The vibrating feeder (5 ') linearly vibrates in the direction of the arrow b by the driving portion (7'). Is a trough (6 ')
Is suspended in a part of the building by coil springs (8a ') and (8b'). In order to detect this amplitude in such an electromagnetic vibration feeder (5 '), the vibration detector (1') shown in FIG. It must be mounted so as to be parallel to the vibration direction b of the trough (6 '). For this purpose, a mounting plate (9 ') projecting laterally from the side of the trough (6') and perpendicular to the direction of vibration must be fixed to the side wall of the trough (6 '), for example by welding.

The above mounting plate (9 ') has no problem at the time of vibration measurement, but when it is not necessary to measure the vibration, the vibration detector (1') is removed from the mounting plate (9 ') but welded. In this case, the mounting member (9 ') cannot be easily removed. Therefore, this is very dangerous because it vibrates as well as disturbs the operation of other devices.
Further, unless the mounting plate (9 ') is mounted in a direction perpendicular to the vibration direction (b) of the trough (6'), the amplitude cannot be measured accurately. Such an accurate mounting operation is very difficult.

In view of the above-described problems, the present applicant aims to provide a vibration detector that can be easily mounted by any person to measure the amplitude easily and accurately. In a vibration detector including a detection element, a casing holding the acceleration detection element, and a mounting member fixed to the casing, the mounting member is mounted on a plane parallel to a vibration direction of a part of the vibration body to be measured. Vibration detector characterized by being detachable in parallel with the detection direction of the acceleration detecting element "(Japanese Utility Model Application No. 2-61258).

Next, the above-described vibration detector will be described with reference to FIG. In FIG. 10, the amplitude detector (40) has a shape as shown in FIG. 12, and this detection force is supplied to a low-pass filter (41), which will be described later. High cycle signal components such as noise are 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 to a digital value, and this digital value is converted to a microcomputer (4).
Supplied to 5). The microcomputer (45) receives the digital output from the A / D converter (43) and the switch signal of the switch section (46), performs a predetermined operation, and supplies the operation result to the liquid crystal display section (47). ing.

Next, the amplitude detector (40) will be described in detail with reference to FIG. It has a substantially cylindrical casing (50), in which an amplitude detecting element (51) made of, for example, lead zirconate 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. Further, a detection output of the detection element position (51) is led out by a conducting wire (53). A vibration display line (55) is engraved on the upper surface of the casing (50). This is marked so as to be parallel to and in the same direction as the detection direction F of the detection element (51) incorporated in the casing (50). It is assumed that a flat magnet is attached to the back surface of the attachment plate (52). Therefore, the whole amplitude detector (40) can be easily attached to and detached from the vibrating body by the magnet.

Next, the mounting operation to the vibrator will be described. In this conventional example, the vibration of the vibration feeder (60) as shown in FIG. 11 is measured. The vibration feeder (60) includes a trough (61) having a U-shaped cross section and a drive unit (62) for transmitting a vibrating force thereto, as is well known. The drive section (62) is configured by a leaf spring, an electromagnet, or the like. The entire vibration feeder (60) is suspended from a part of the building by the coil springs (63a) (63b). When a commercial power supply is supplied 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 l. Vibration detector (40) shown in Fig. 12
When the mounting plate (52) is applied to the side surface of the trough (61), the mounting plate (52) is easily fixed to the side surface of the trough (61) by the magnet mounted on the back surface. Although the vibration detector (40) vibrates together with the trough (61), a vibration display line (55) is engraved on the upper surface of the casing (50). In the first mounting, the vibration is displayed in such a manner that it is parallel to the expected vibration direction l. However, if the vibration display line (55) is sufficiently thin and accurately coincides with the vibration direction, the thickness of the line at rest and the thickness are approximately If they are the same, but are tilted in either direction, they remain on the retina of the eye as afterimages, so they can be viewed with a certain width or a tilted width. Therefore, while watching this, the vibration display line at rest (55)
Adjust the mounting direction while pinching the casing (50) so that it is approximately the thickness of the casing. When the magnet is fixed to the side surface of the trough (61) at a predetermined angle by the magnet, the direction is parallel to and coincides with the detection direction F of the detection element (51) made of lead zirconate in the casing (50). The amplitude can be measured accurately. This amplitude detection force, that is, the voltage, is supplied to the low-pass filter (41) shown in FIG. 10 via the conducting wire (53). The detected force from the amplitude 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 shape as shown by a waveform S. By passing through the low-pass filter (41), the ripple-like noise is removed as a high frequency component as shown on the output side, and the low frequency component signal S 'is supplied to the amplifier (42). Here, the signal is amplified to a predetermined size and supplied to the A / D converter (43).

The output of the microcomputer (45) is LCD (Liquid Crystal Displa)
y) It is supplied to the liquid crystal display (47). That is, the amplitude of the vibration feeder (60) calculated by the microcomputer (45) is displayed as a digital value on the display unit. That is, it can be seen that the amplitude of the vibration feeder (60) being measured is 1.25 mm. Conventionally, the amplitude nameplate (1) as shown in FIGS. 6 and 7 is attached to the side surface of the trough (61) so that the scale line (3) coincides with the vibration direction, and the amplitude display line (4a) is used. (4) The operator reads this intersection using the residual image of the retina of the eye in (4b). However, as described above, there is an individual difference, and it changes depending on the surrounding conditions. According to this conventional example, the amplitude can be measured more accurately than with the amplitude nameplate (1).
It is difficult to attach the casing (50) to the vibrating body so that the amplitude display line (55) exactly coincides with the direction of vibration, and the accuracy is considerably influenced by the skill of the measurer.

[Problems to be solved by the invention]

The present invention has been made in view of the above-described problems, and has as its object to provide a method of measuring the amplitude, which can be easily and accurately measured by any measurer.

[Means for solving the problem]

The object described above is to mount an amplitude detection element for detecting the amplitude of vibration in a predetermined direction at a first position on a plane parallel to the vibration direction of the vibrating body to be measured and to attach the first element to the first position of the amplitude detection element. Measuring a detection output a, and then mounting the sensor at a second position perpendicular to the first position to measure a second detection output b of the amplitude detecting element; And the second
From the detection output b Is calculated, and the amplitude of the vibrating body to be measured is measured from the calculation result.

[Action]

There is no need to match the amplitude detection direction of the amplitude detection element with the vibration direction of the vibrating body to be measured, and simply change the attachment to the first and second positions, and the skill of the measurer is not related at all. There is no. The first position and the second position are in a right angle relationship, but these may be inscribed in advance, for example, on the mounting plate of the amplitude detecting element. The mounting position of the mounting plate may be changed according to the indication of the detecting element that can be freely mounted on the vibrating body to be measured.

〔Example〕

Hereinafter, an amplitude detecting apparatus embodying the method of the present invention will be described with reference to FIGS. The same reference numerals are given to portions corresponding to FIGS. 6 to 12 of the conventional example, and detailed description thereof will be omitted.

FIG. 1 corresponds to FIG. 10 of the prior art, but according to this embodiment, an amplitude detector (80) as shown in FIG. 3 and FIG. The signal is supplied to a low-pass filter (41), an amplifier (42) and the like as in the prior art, and the microcomputer (45 ') uses two detection outputs a and b as described later. Is performed. The result is supplied to the LCD converter (47 '), and the amplitude of the vibrating body to be measured is displayed as a digital value. A changeover switch (46) for the microcomputer (45 ')
Is connected, and when the position of the amplitude detector (80) is changed to a position perpendicular to this position, the changeover switch (46) is switched to change the detection output a at the first position to the microcomputer (45). ') The data is stored in the first storage circuit, and then the detection output b at the second position is changed over by the changeover switch (46).
Is supplied to the second storage circuit by the switching, and is supplied to the operation unit of these stored values a and b. Is calculated.

Next, the amplitude detector (80) according to the present invention will be described with reference to FIGS. 3 and 4. FIG.

The cylindrical casing (50) has the same shape as the conventional one, but the flange portion (50b) is turned with respect to the mounting plate (81) in the direction of the center line CC as shown by the arrow R. It is mounted so that it can move freely. That is, holes (50a) for bolt insertion are formed in the flange portion (50b) at predetermined angular intervals. The mounting plate (81) has a rectangular shape as in the prior art, but has a magnet on its bottom wall for mounting the entire amplitude detector (80) to a vibrating body to be measured, for example, a trough of a vibration feeder. No, instead of bolt holes (81a)
The mounting plate (81) is mounted by inserting bolts into these and screwing them into the screw holes of the trough (61) of the vibrating body to be measured, for example, the vibrating feeder (60). This mounting position is free. That is, it is not necessary to attach the mounting plate (81) to the trough (61) so that the vibration indicating line formed on the surface of the casing (50) coincides with the vibration direction as in the related art, but in a plane including the vibration direction. It can be mounted at any position and at any angle.

The mounting plate (81) is attached to the mounting plate (81) of the casing (50).
That is, the first position indicating line (81b) is used to position the first position and the second position with respect to the trough (61).
-(81b) and display line (81c) for second positioning-
(81c) is engraved. Correspondingly, the first position and the second position are also provided at 90 ° intervals on the flange portion of the casing (50).
The display line (50c)-(50c) for the position of is engraved,
As shown in FIG. 4, by mounting one of the display lines so as to be aligned with the display lines (81c)-(81c) of the mounting plate (81), the amplitude detector (80) is in the first position. The indicator line (50c)-(50c) can be attached to the mounting plate (8
1) By mounting the casing (50) on the mounting plate (81) so as to be aligned with the other display lines (81b)-(81b),
The amplitude detector (80) can be mounted at a second position relative to the trough. The amplitude detecting element (51) made of lead zirconate is built in the casing (50) as in the conventional case. The detection direction of the amplitude of the detection element (51) is mounted so as to be aligned with the display line (50c)-(50c) of the flange portion of the casing (50).

The embodiment of the present invention is configured as described above. Next, its operation will be described.

As described above, if the mounting plate (81) of the amplitude detector (80) of the present embodiment is on a plane parallel to the vibration direction 1 of the trough (61) of the vibration feeder (60) as the vibration object to be measured. , May be mounted at any angle. For example, it is assumed that they are mounted at angles as shown in FIG. In addition, in FIG. 3, the display line (50c)-(50c) of the flange portion (50a) of the casing (50) is attached to the mounting plate (81) for mounting at the first position.
By aligning them with the indication lines (81b)-(81b), the bolt is inserted into the bolt insertion hole (50b) at this position, and screwed into the screw hole of the mounting plate (81) to tighten.
The casing (50) is positioned and fixed to the mounting plate (81).

If the vibration feeder (60) is driven in the above state, the output from the amplitude detector (80) is supplied to the low-pass filter (41) as shown in FIG. In (45 '), the amplitude detection value a at this time
Is stored in the first storage circuit of the CPU (45 ').

Next, the bolts inserted through the flange portion (50a) of the casing (50) are removed, and are deviated by 90 degrees from the above first position to be positioned and mounted at the position of the mounting plate (81). That is, the display line (50c) of the flange (50a)
(50c) is changed to the indicator line (81c)-(81
After being aligned in c), the bolt is inserted into the bolt insertion hole of the flange portion and screwed into the screw hole of the mounting plate (81) to be positioned and fixed at the second position. In this state, the output from the amplitude detector (80) is supplied to the second storage circuit in the microcomputer (45 ') through the low pass filter (41) and the following circuits, and the detection output b at this time is supplied to the second storage circuit. You. Prior to this, the switch (46) is switched so that the second amplitude value b is supplied to the second storage circuit of the microcomputer (45 '). The first and second amplitude detection values a supplied to the first and second storage circuits of the microcomputer (45 ')
And b are supplied to the arithmetic unit, where Is calculated. The calculation result is supplied to the LCD converter (47 '), that is, the amplitude value is supplied, and the amplitude is displayed as a digital value on a display unit of a device (not shown). According to this embodiment, the amplitude of the vibrating body to be measured can be accurately measured irrespective of the skill of the measurer. However, referring to FIG. The fact that the amplitude value is not affected at all will be described.

That is, in FIG. 5, when the detection direction is in the x direction, the first position is set, and in the y direction, the second position is set. In this case, when the amplitude detection value at the first position is a and the detection value at the second position is b, the amplitude of the vibration body to be measured is clearly Becomes Since the mounting angle of the mounting plate (81) with respect to the trough is different, the first position is x 'and the second position is y' in the detection direction of the detection element (51) in the casing.
At this time, as long as the amplitude V is constant, the amplitude detection value at the first position should be a 'and the detection value at the second position should be b'. Therefore, the calculated value at this time Clearly in the mounting position described above Is equivalent to As is clear from the above, no matter what angle the mounting plate (81) is attached to the measured object, that is, the trough of the vibration feeder, the mounting plate (8
1) The amplitude of the vibrating body to be measured can be accurately detected if the upper casing (50), that is, the mounting position of the detection element incorporated therein is positioned at the first position and the second position. You can see that.

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

For example, in the above embodiment, the mounting plate (81) is previously mounted on the trough of the vibration feeder, and the mounting plate (81) is mounted.
However, the relative position of the casing (50) is changed so that the first position and the second position can be taken. Instead, the casing (50) is fixed to the mounting plate (81). In the same manner as before, a magnet is mounted on the bottom surface of the mounting plate (81), and the mounting plate (81) is mounted on the side wall of the trough by the magnetic force of the magnet. The display lines of the mounting plate (81) are displayed by the first and second lines by some means.
The amplitude detection values of the amplitude detection elements at the first position and the second position may be obtained by mounting the sensor in alignment with the display line for displaying the position.

Alternatively, without using the mounting plate (81), the casing (50), or the like, the amplitude detecting element itself may be angularly deflected to the first and second positions with respect to the vibrating body to be measured. .

[Effects of the Invention] As described above, according to the amplitude measuring method of the present invention,
Regardless of the skill level of the measurer, the amplitude of the vibrating body to be measured can always be measured accurately.

[Brief description of the drawings]

FIG. 1 is a block diagram of an amplitude detection device embodying the method of the present invention, and FIG. 2 is a schematic side view showing a situation where the amplitude detector in the device is attached to a trough of a vibration feeder as a measured object. FIG. 3 is a perspective view of the same amplitude detector, FIG. 4 is a plan view of the same amplitude detector, FIG. 5 is a graph for explaining the operation of the same device, and FIG. FIG. 7 is a plan view of a width nameplate, FIG. 7 is a plan view for explaining the same operation, FIG. 8 is a front view of another conventional amplitude detector, and FIG. 9 is a trough of a vibration feeder. FIG. 10 is a block diagram of a conventional amplitude device, FIG. 11 is a side view showing a condition where an amplitude detector in the device is attached to a trough of a vibration feeder, and FIG. The figure is a perspective view of the amplitude detector. In the figure, (45 ') ... microcomputer (46) ... changeover switch (50) ... casing (60) ... vibration feeder (61) ... trough (80) ... amplitude detector (81) ... … Mounting plate

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01H 1/00 G01H 11/00

Claims (1)

(57) [Claims] An amplitude detecting element for detecting an amplitude of a vibration in a predetermined direction is provided on a surface parallel to a vibration direction of a vibration body to be measured.
It is attached to a first position and measures a first detection output a of the amplitude detecting element. Then, it is attached to a second position perpendicular to the first position and is attached to a second position of the amplitude detecting element. 2 from the first detection output a and the second detection output b. And calculating the amplitude of the vibrating body to be measured from the calculation result.