JPH01167624A - Tension measuring instrument - Google Patents

Abstract

PURPOSE:To determine tension in a state of non-contact with a body to be measured by vibrating the body to be measured forcibly with a sound and detecting its vibration waveform, finding a frequency spectrum, and determining the tension according to the spectrum. CONSTITUTION:A driving signal generation part 7 generates a driving signal according to a basic signal oscillated by a frequency determination part 5 and a timing signal oscillated by an output timing adjustment part 6 and a sound source part 4 generates the sound. A displacement sensor part 8 detects the quantity of displacement of a tape 1 which vibrates with the sound generated by the sound source 4. A vibration waveform generation part 9 generates the vibration waveform according to the output of the displacement sensor part 8. A waveform analytic part 15 analyzes the waveform to find the frequency spectrum. A central arithmetic unit 12 determines the tension according to the frequency spectrum.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a tension measuring device that measures the tension of an object to be measured in a non-contact state, and particularly relates to a tension measuring device that measures the tension of an object to be measured using sound. It is related to the device.

[Prior Art] Conventionally, when measuring the tension of a flexible object such as a tape, a predetermined load is applied to the supported object to deform it, and then the object is deformed. Generally, the measured value is obtained based on the amount of displacement of the object to be measured.

Therefore, an example of a conventional tension measurement method will be described below.

FIG. 8 is a schematic configuration diagram showing a conventional tension measuring device.

In the figure, a flexible tape 50 is connected to a sensor section 51.
The tape support post 52b is hung and supported by three tape support posts 52a, 52b, and 52c in a substantially linear shape, and in particular, the tape support post 52b is movable in the vertical direction indicated by the arrow. Further, one end 50a of the tape 50 is wound around a tape support vibrator 54 attached to the moving stage 53, and the adhesive tape 50 is
It is fixed by 5. Also, the other end 50b of the tape 50
(not shown) are tape support posts 52a, 52b,
It is fixed to a post (not shown) other than 52c. The movement of the moving stage 53 is controlled by a coarse movement micrometer 56.
adjusted by.

In such a configuration, conventionally, the drive stage 53 is moved in the direction of arrow S to give tension to the tape 5o.
At this time, the tension is determined based on the amount of displacement in the direction of the arrow P of the tape support post 52b, which acts to apply a load to the tape 50 in the direction of the arrow P. For example, by electrically or optically detecting the amount of displacement of the tape support post 52b from the reference position, the detected amount is converted into force to determine the tension.

[Problems to be Solved by the Invention] However, when applying a load while in contact with the tape, such as with a tape support post, it not only deforms the tape 50 but also damages the detection mechanism of the tape support post, etc. There is a problem in that friction occurs between the tape and the tape. With such a tension measuring device, it is very difficult to obtain reliable measured values.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a tension measuring device that can obtain highly reliable measured values.

[Means for Solving the Problems] In order to solve the above-mentioned problems and achieve the purpose, the tension measuring device according to the present invention is a tension measuring device that measures tension by vibrating the object to be measured using sound. vibration generating means for generating forced vibrations in the object to be measured by sound; waveform detecting means for detecting a predetermined vibration waveform based on the forced vibration; and spectrum analysis for obtaining a frequency spectrum based on the predetermined vibration waveform. and tension determination means for determining tension based on the frequency spectrum.

[Operation] According to the above configuration, the vibration generating means generates forced vibration in the object to be measured using sound, and the waveform detecting means detects a predetermined vibration waveform based on the forced vibration. The spectrum analysis means obtains a frequency spectrum based on the vibration waveform, and the tension determination means determines the tension based on this frequency spectrum.

In this way, the tension can be accurately measured without contacting the object to be measured.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Description of the configuration of the tension measuring device according to the present embodiment (FIG. 1)> FIG. 1 is a schematic configuration diagram showing the configuration of the tension measuring device according to the present embodiment (hereinafter referred to as the present device).

In FIG. 1, reference numeral 1 indicates a flexible tape, and reference numerals 2 and 3 indicate tape support vibrators spaced apart by a predetermined width depending on the method for measuring the tension of the tape 1. The vicinity of both ends of the tape are fixed along the respective peripheral surfaces of the tape support vibrator 2.3 with an adhesive such as double-sided tape. Reference numeral 4 denotes a sound source section that generates sound in response to a drive signal transmitted from a drive signal generation section 7, which will be described later. The positional relationship between the sound source section 4 and the tape 1 is such that the sound output from the sound source section 4 propagates through the air and the tape 1
The setting is made so that the amount of attenuation of the sound from the time when the sound is incident perpendicularly to the tape 1 to the tape 1 is attenuated to a minimum. Reference numeral 5 denotes a frequency determination unit comprising an oscillation circuit that determines the frequency of the sound output from the sound source unit 4 and oscillates a signal at that frequency, and 6 oscillates a signal that outputs the signal of the frequency determination unit 5 at a predetermined timing. This is an output timing adjustment section equipped with an oscillation circuit. Further, 7 creates a product of the respective signals oscillated from the frequency determining section 5 and the output timing adjusting section 6, and applies the signal formed by the product to the sound source section 4 as a driving signal for the sound that vibrates the tape 1. This is a drive signal generation section.

Further, 8 is a displacement sensor unit that optically detects the displacement amount due to vibration of the tape 1, and 9 is a vibration waveform generation unit that generates a vibration waveform for vibrating the tape 1 from the displacement amount detected by the displacement sensor unit 8. . Note that this vibration waveform indicates the frequency of the tape 1. Reference numeral 10 denotes a tension determination unit that determines the tension based on the vibration waveform generated by the vibration waveform generation unit 9, and 11 displays the tension determined by the tension determination unit 10 as a measured value or displays a frequency spectrum to be described later. It is a display section with functions. In particular, the display on the display section 11 is switched by a switch provided in the display section.

Note that the signal oscillated by the frequency determination section 5 is referred to as a basic signal, and the signal oscillated from the output timing adjustment section 6 is referred to as a timing signal.

Next, the internal configuration of the tension determining section 10 will be described. 12 is a CPU that controls the entire tension determining section 10; 13 is a ROM that stores a control program for the tension determining section 10, an error handling program, a program for executing the flowchart shown in FIG. 7, etc.; 14 is a ROM 4; This RAM has a working area for executing various stored programs and a temporary save area during error processing. Especially R.O.
M13 stores a table of tension data groups corresponding to spectral intensity ratios, which will be described later. In other words, the tension data group of this example is a data group of tabular graphs showing the relationship between spectral intensity ratio and tension used in the conventional tape contact type tension measurement method, compared to the case of the tape non-contact type tension measurement method. It is calibrated to the data group and tabulated.

Reference numeral 15 denotes a waveform analysis section that analyzes the vibration waveform of the AC component generated by the vibration waveform generation section 9 to obtain a frequency spectrum. Reference numeral 16 denotes an interface unit that receives signals from the vibration waveform generating unit 9, and 1f an interface unit that transmits measured values to the display unit 11. A system bus 18 includes an address bus, a data bus, a control path, and the like.

Further, 19 to 24 are connection cables that connect each part.

The tension measuring device configured as described above independently implements a vibration generation method in which the tape 1 is vibrated by sound propagated in the air, and a tension determination method in which the tension is determined based on the displacement of the tape 1 due to vibration. do.

Explanation of how to generate vibration (Figure 2) First, the vibration generation method will be explained below.

FIG. 2 is a timing chart illustrating the sound generation method according to this embodiment. In the figure, A is the basic signal oscillated by the frequency determining section 5, B is the timing signal oscillated from the output timing adjustment section 6, and C is the driving signal. This is a drive signal generated by the signal generator 7. Further, T is the period of the timing signal B, and t is the time for adjusting the output time of the basic signal A.

The drive signal C formed by the product of the basic signal A and the timing signal B is a composite signal that causes the sound source section 4 to generate sound by adjusting the output timing of the basic signal A, which determines the frequency of the sound, with the timing signal B. In other words, the drive signal generator 7
Then, the drive signal C is generated with a period T consisting of a time t during which the sound source section 4 generates sound and a time T-t during which no sound is generated.

In particular, a drive signal set to output "0" volts is applied to the sound source section 4 during the time (Tt).

According to the above explanation, the sound source 4 generates sound in response to the drive signal C for a period of time t every period T, and the tape 1 attenuates every period T according to the frequency of the sound propagating in the air. It generates vibration.

In this way, the tension measuring device of this embodiment employs a tension measuring method based on the damped vibration of the object to be measured.

Description of tension determination method (FIGS. 3 to 7)> Next, the tension determination method will be described below.

First, the displacement sensor unit 8 detects the amount of displacement of the tape 1 that vibrates with the sound generated by the sound source 40. Then, the displacement amount is continuously sent from the displacement sensor section 8 to the vibration waveform generation section 9, and the vibration waveform generation section 9 generates a vibration waveform based on the displacement amount. Further, the vibration waveform generated by the vibration waveform generation section 9 is analyzed by the waveform analysis section 15 to obtain a frequency spectrum.

Next, the frequency spectrum from the above-mentioned vibration waveform will be explained using FIGS. 3 to 6.

3 and 4 are diagrams showing vibration waveforms due to continuous damped vibration of the tape 1. Figure 5 is a diagram showing the relationship between frequency spectrum intensity and frequency obtained by analyzing the vibration waveform in Figure 3, and Figure 6 is a diagram showing the relationship between frequency spectrum intensity and frequency obtained by analyzing the vibration waveform in Figure 4. It is a diagram.

In particular, when the vibration waveforms indicating damped vibration are different as shown in FIGS. 3 and 4, this indicates that the tape 1 is being supported with different tensions during measurement due to the difference in damping rate.

Furthermore, in FIGS. 5 and 6, the vertical axis represents frequency spectrum intensity, and the horizontal axis represents frequency. p1 to p4 and q1 to q
4 is the frequency spectrum intensity at the peak position of the vibration waveform, and W, ~W4 and ul#u4 are frequencies corresponding to the frequency spectrum intensities PI""P4 and q, ~q4.

The frequency spectra shown in FIGS. 5 and 6 obtained by the waveform analysis section 15 described above can be displayed on the display section 11. In this case, frequency spectrum data is sent from the tension determining section 10 to the display section 11, and the switch on the display section 11 at this time is set to the frequency spectrum side.

Next, the method for determining tension from the frequency spectrum will be explained in the seventh section.
The explanation will be made according to the flowchart shown in the figure, with reference to the frequency spectra shown in FIGS. 5 and 6.

First, two peak positions of a frequency spectrum having the minimum intensity among the frequency spectra and a frequency spectrum having the next highest intensity after this minimum frequency spectrum are detected.

For example, in the case of Fig. 5, the peak position E+(w+,
P+ ) and F2 (w,,p2) are taken out, and in the case shown in FIG. 6, P+(u+) at the peak position.

ql) and F2 (uz, Q2) (step Sl). Then, the frequency spectrum intensities of the peak positions E and F2 or the peak positions F and F2 are obtained (step S2), and the spectrum intensity ratio is calculated by the following method. That is, of the first and second peak positions, the intensity ratio obtained by dividing the higher frequency spectral intensity by the lower frequency spectral intensity is set as the spectral intensity ratio. For example, peak position E, %E
The spectral intensity ratio in the case of 2 is R1 peak potential electric F
, , Letting S be the spectral intensity ratio in the case of F2, the following equations hold true. That is, (step S3).

Next, the tension corresponding to the spectral intensity ratios R and S determined based on the above equations (1) and (2) is determined.

First, the spectral intensity ratio R or S obtained in step S3
is the relative address of the tension table stored in the ROM 13. When the spectral intensity ratio R is calculated, tension data is taken out from the table using R as a relative address, and when the spectral intensity ratio S is calculated, tension data is taken out from the table using S as a relative address. In this way, the soot tension corresponding to each spectrum intensity ratio is determined (step S4). Also, step S4
The tension determined in step S5 is stored in a predetermined storage area of the RAM 14.

Next, the position of the switch on the display unit 11 is detected (step S6), and if it is “tension display”, the determined tension data is sent to the display unit 11 (step S7), and if it is “frequency spectrum display” If so, the frequency spectrum data is sent to the display section 11 (step S8).

As explained above, according to this embodiment, it is possible to determine the tension from the vibration of the object to be measured in a non-contact manner using sound. In other words, since friction, which has been a problem with contact-type tension measuring devices, is eliminated, the reliability of measured values is improved.

Moreover, it is also possible to modify the tension measuring device of this embodiment as follows.

That is, according to the first modification, the sound source 4 and the displacement sensor section 8
may be placed at a position facing the object to be measured.

According to the second modification, similar actions and effects can be obtained by using a displacement meter using electrical or magnetic means instead of using the optical displacement detection method using the displacement sensor section 8.

According to the third modification, it is also possible to measure the tension of an object that can be easily deformed using a string, paper, or the like other than tape.

[Effects of the Invention] As described above, according to the present invention, it is possible to measure tension without contacting the object to be measured, and the reliability of measured values can be improved.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram showing the configuration of the tension measuring device of this embodiment, Fig. 2 is a timing chart explaining the sound generation method according to this embodiment, and Figs. 3 and 4 are vibrations according to this embodiment. A diagram showing different vibration waveforms output from the waveform generator 9, FIG. 5 is a diagram explaining a method for determining the tension corresponding to the vibration waveform shown in FIG. 3, and FIG. 6 is a diagram showing the vibration waveform shown in FIG. 4. FIG. 7 is a flowchart explaining the tension determination method according to the present embodiment, and FIG. 8 is a schematic configuration diagram showing a conventional tension measuring device. In the figure, 1... tape, 2, 3. 54... tape support vibrator, 4... sound source section, 5... frequency determination section, 6.
... Output timing adjustment section, 7... Drive signal generation section,
8... Displacement sensor section, 9... Vibration waveform generation section, 10
... Tension determining section, 11... Display section, 12... CP
U513...-ROM, 14...-RAM, 15...
Waveform analysis section, 16, 1... Interface section, 1
8...System bus, 50...Tape, 51...
Senna portion, 52a, 52b, 52c...Tape support post, 53...Moving stage, 55...Adhesive tape, 56...Coarse movement micrometer. ] wl W2 W3 W4/i! ilJ
Number 5 ul u2 L12 LJ4 Shukyaku Figure 6;-

Claims (5)

[Claims] (1) A tension measuring device that measures tension by vibrating an object to be measured using sound, comprising a vibration generating means for generating forced vibration in the object to be measured using sound, and a predetermined vibration waveform based on the forced vibration. A tension measuring device comprising: a waveform detection means for detecting; a spectrum analysis means for determining a frequency spectrum based on the predetermined vibration waveform; and a tension determination means for determining tension based on the frequency spectrum. (2) The vibration generating means includes a frequency determining means for determining the output frequency of the sound, and a timing adjusting means for adjusting the output timing of the sound. Tension measurement means. (3) The tension measuring means according to claim 2, wherein the frequency determining means includes a frequency adjusting means that allows the output frequency to be changed according to the vibration response of the object to be measured. (4) Claim 1, characterized in that the tension determination means determines the tension based on the intensity ratio of the frequency spectrum.
Tension measuring means described in Section 1. (5) The tension measuring means according to claim 4, wherein a data group of tension corresponding to the intensity ratio is stored in advance.