JP2017129554A - Apparatus and method for measuring attenuation coefficient of long material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an attenuation coefficient measuring apparatus for a long material that can measure the attenuation coefficient of a long material easily and simply.SOLUTION: The apparatus for measuring the attenuation coefficient of a long material includes: a tension addition mechanism for adding a specific tension to a long material in a longer direction while holding both edges of the long material; a tension measuring section for measuring a change in the tension of the long material when the long material, which has received the addition of the specific tension in the longer direction, makes damped oscillation; and an operation processing section for operating the attenuation coefficient of the long material based on the result of measurement by the tension measuring section.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a long material attenuation coefficient measuring apparatus and a long material attenuation coefficient measuring method. In particular, the present invention relates to a long material attenuation coefficient measuring apparatus that can easily measure the attenuation coefficient of a long material with a simple configuration, and a long material attenuation coefficient measuring method that can easily measure the attenuation coefficient of a long material.

  Mechanical products and structures may vibrate (damped vibration) due to external factors, and it is desired from the viewpoint of quality improvement and improvement to understand the behavior associated with the vibration. In order to grasp the behavior associated with vibration, it is possible to measure the damping coefficient. For example, a dynamic viscoelasticity measuring apparatus (Non-Patent Document 1) is used for measuring the attenuation coefficient.

  The measurement of the damping coefficient using the dynamic viscoelasticity measuring apparatus is as follows. Both ends of the test piece are held by the holding portion, and a constant tension is applied in the longitudinal direction of the test piece. In this state, a sinusoidal vibration is applied to the test piece in the longitudinal direction. At this time, a dynamic stress along the longitudinal direction is applied to the test piece by vibration, and dynamic strain is generated in response thereto. The dynamic stress and dynamic strain are measured. The dynamic stress and the dynamic strain are attenuated in magnitude according to the vibration attenuation and have a phase difference. The attenuation coefficient is obtained using this magnitude and the phase difference.

“Guidelines for analytical instruments Laboratory analytical instruments 1.7 Dedicated measuring device Viscoelasticity measuring device”, p. 105, [online], [Search on December 11, 2015], Internet <URL: http: // www. jaima. or. jp / jp / tebiki />

  In order to simulate how long materials such as electric wires vibrate, what kind of load is applied to the long material during vibration, and the ease of convergence of the vibration, it is necessary to determine the damping coefficient of the long material. It is desired. The attenuation coefficient can be measured by using a dynamic viscoelasticity measuring apparatus as described above, but the development of an apparatus and method that can be measured with a simpler configuration is desired.

  The present invention has been made in view of the above circumstances, and one of its purposes is to provide a long material attenuation coefficient measuring apparatus that can easily measure the attenuation coefficient of a long material with a simple configuration. is there.

  Another object of the present invention is to provide a method for measuring the attenuation coefficient of a long material, in which the measurement of the attenuation coefficient of the long material is simple.

  A long material attenuation coefficient measuring apparatus according to an aspect of the present invention includes a tension applying mechanism, a tension measuring unit, and an arithmetic processing unit. The tension applying mechanism grips both ends of the long material and applies a constant tension in the longitudinal direction of the long material. The tension measuring unit measures a change in tension of the long material when the long material to which a constant tension is applied in the longitudinal direction undergoes damped vibration. The arithmetic processing unit calculates the attenuation coefficient of the long material based on the measurement result of the tension measuring unit.

  The long material damping coefficient measuring method according to one aspect of the present invention includes a tensioning step, a vibration applying step, a measuring step, and a calculating step. In the tensioning step, a constant tension is applied in the longitudinal direction of the long material. In the vibration applying step, the long material to which a constant tension is applied in the longitudinal direction is damped and vibrated. In the measurement step, a change in tension of the long material that undergoes damped vibration is measured. In the calculation step, the attenuation coefficient of the long material is calculated based on the measurement result in the measurement step.

  The long material attenuation coefficient measuring apparatus can easily measure the attenuation coefficient of a long material with a simple configuration.

  The method for measuring the attenuation coefficient of the long material is simple in measuring the attenuation coefficient of the long material.

It is process explanatory drawing explaining the schematic structure of the attenuation coefficient measuring apparatus of the long material which concerns on Embodiment 1, and the procedure of the attenuation coefficient measuring method of a long material. It is operation | movement explanatory drawing explaining the schematic structure of the vibration provision mechanism with which the damping coefficient measuring apparatus of the long material which concerns on Embodiment 2 is equipped, and operation | movement of a vibration provision mechanism. Sample No. 1 of Test Example 1 2 is a graph showing a waveform of tension transition in 1. FIG. Sample No. 1 in Test Example 1 It is a graph which shows the simulation result of 100.

<< Description of Embodiments of the Present Invention >>
First, embodiments of the present invention will be listed and described.

  (1) A long material attenuation coefficient measuring apparatus according to an aspect of the present invention includes a tension applying mechanism, a tension measuring unit, and an arithmetic processing unit. The tension applying mechanism grips both ends of the long material and applies a constant tension in the longitudinal direction of the long material. The tension measuring unit measures a change in tension of the long material when the long material to which a constant tension is applied in the longitudinal direction undergoes damped vibration. The arithmetic processing unit calculates the attenuation coefficient of the long material based on the measurement result of the tension measuring unit.

  According to said structure, the attenuation coefficient of a long material can be measured simply with a simple structure. Because it is possible to calculate the damping coefficient from the transition of tension when a long material is damped and vibrated with a constant tension applied to the long material, simply by providing a tension adding mechanism, a tension measuring unit, and an arithmetic processing unit. is there. On the other hand, in the case of the above-described dynamic viscoelasticity measuring apparatus, a motor mechanism that applies sinusoidal vibrations of various frequencies to the test piece is necessary. Moreover, according to said structure, there are many choices of the material of the elongate material which can measure a damping coefficient compared with a dynamic viscoelasticity measuring apparatus. This is because the above-described dynamic viscoelasticity measuring apparatus needs to detect strain as described above, and thus it is difficult to measure the damping coefficient with a metal material or the like that is difficult to detect strain.

  (2) As one form of the above-described long material attenuation coefficient measuring apparatus, an external force is applied in a direction orthogonal to the longitudinal direction to a part of the long material to which a constant tension is applied in the longitudinal direction. It is possible to include a vibration applying mechanism that dampens and vibrates the long material by displacing a part of the material and releasing the external force.

  According to said structure, adjustment of the external force given to a long material is easy by providing the vibration provision mechanism which carries out a damping vibration of a long material.

  (3) The long material damping coefficient measuring method according to one aspect of the present invention includes a tensioning step, a vibration applying step, a measuring step, and a calculating step. In the tensioning step, a constant tension is applied in the longitudinal direction of the long material. In the vibration applying step, the long material to which a constant tension is applied in the longitudinal direction is damped and vibrated. In the measurement step, a change in tension of the long material that undergoes damped vibration is measured. In the calculation step, the attenuation coefficient of the long material is calculated based on the measurement result in the measurement step.

  According to said structure, the measurement of the attenuation coefficient of a elongate material is simple. This is because the damping coefficient can be calculated from the change in tension by simply damping the long material with a certain tension applied to the long material.

<< Details of Embodiment of the Present Invention >>
Details of Embodiments 1 and 2 of the present invention will be described below with reference to the drawings. The same reference numerals in the figure indicate the same names. The description of each embodiment will be made in the order of a long material attenuation coefficient measuring device and a long material attenuation coefficient measuring method. The present invention is not limited to these exemplifications, but is defined by the scope of the claims, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims.

Embodiment 1
[Attenuation coefficient measuring device for long materials]
With reference to FIG. 1, the elongate material attenuation coefficient measuring apparatus 1 according to the first embodiment will be described. The long material attenuation coefficient measuring apparatus 1 measures the attenuation coefficient of the long material 10. The main characteristic of the long material attenuation coefficient measuring apparatus 1 is that the attenuation coefficient of the long material 10 is obtained based on a change in tension of the long material 10. The long material attenuation coefficient measuring apparatus 1 includes a tension applying mechanism 2, a tension measuring unit 3, and an arithmetic processing unit 4. Details of each component will be described below.

[Tensioning mechanism]
The tension applying mechanism 2 applies a constant tension in the longitudinal direction of the long material 10 (left figure in FIG. 1). The tension applying mechanism 2 includes a main body (not shown), a pair of gripping portions 21a and 21b, a moving mechanism 22, and a pedestal portion 23. The pair of grip portions 21 a and 21 b grip both ends of the long material 10. Of the pair of gripping portions 21 a and 21 b, one gripping portion 21 a is attached to the moving mechanism 22, and the other gripping portion 21 b is fixed to the pedestal portion 23. The moving mechanism 22 slides one grip part 21a along the direction facing the other grip part 21b. The moving mechanism 22 is slidably fixed to the main body (not shown) of the tension applying mechanism 2. As the moving mechanism 22, a servo mechanism or the like can be used. The pedestal portion 23 fixes the other gripping portion 21b so as not to slide in the facing direction. That is, the tension is applied to the long material 10 by the tension applying mechanism 2 by sliding the one gripping portion 21 a away from the other gripping portion 21 b by the moving mechanism 22. The type of the long material 10 to be measured is not particularly limited and can be selected as appropriate. As this long material 10, for example, an electric wire, an electric wire with a connecting portion in which a connecting portion is connected to an end portion of the electric wire, or the like can be used.

[Tension measuring section]
The tension measuring unit 3 measures a change in tension of the long material 10. Thereby, the time for which the long material 10 damped and vibrated converges to a constant tension is also obtained. The tension measuring unit 3 may be a load cell that converts the tension of the long material 10 into an electrical signal and outputs the electrical signal. As the response speed (response frequency) of the load cell becomes faster (higher), the change in tension can be measured more precisely. The response speed (response frequency) of the load cell is preferably 100 ms (milliseconds) or less (10 Hz or more), more preferably 10 ms or less (100 Hz or more), and particularly preferably 1 ms or less (1000 Hz or more). The tension measuring unit 3 is attached to one gripping part 21a. The measurement result by the tension measuring unit 3 is output to the arithmetic processing unit 4. A commercially available tensile testing machine can be used for the tension applying mechanism 2 and the tension measuring unit 3.

[Operation processing unit]
The arithmetic processing unit 4 calculates the attenuation coefficient of the long material 10 based on the measurement result of the tension measuring unit 3. Thereby, the convergence time of the transition of the tension in the long material 10 can be obtained from the transition of the tension obtained by the measurement of the tension measuring unit 3. That is, it can be understood how the long material 10 vibrates and how easily the long material 10 converges. The arithmetic processing unit 4 can use a computer. The computer may be provided with a monitor 40 and displayed on the monitor 40 as a waveform. By doing so, it is possible to visually confirm the transition of the tension and the convergence time of the transition of the tension.

[Effects of long material damping coefficient measuring device]
According to the long material attenuation coefficient measuring apparatus 1 of the first embodiment, the long material 10 is applied with a constant tension only by including the tension applying mechanism 2, the tension measuring unit 3, and the arithmetic processing unit 4. The damping coefficient can be calculated from the change in tension when the long material 10 is damped and vibrated. Therefore, the attenuation coefficient of the long material can be easily measured with a simple configuration.

[Measurement method of long material damping coefficient]
The long material attenuation coefficient measurement method measures the attenuation coefficient of a long material. This method for measuring the attenuation coefficient of a long material includes a tensioning step, a vibration applying step, a measuring step, and a calculating step. In this measurement method, the above-described long material attenuation coefficient measuring apparatus 1 can be used.

[Tensing process]
In the tensioning step, a constant tension is applied in the longitudinal direction of the long material 10. Here, as shown in the left diagram of FIG. 1, both ends of the long material 10 are gripped by the gripping portions 21a and 21b, and the long material gripped by the gripping portions 21a and 21b as shown in the second diagram from the left in FIG. Pull one end of the two ends. That is, one gripping part 21a is moved in a direction away from the other gripping part 21b. When the movement amount of one gripping portion 21a reaches a predetermined amount, the movement of one gripping portion 21a is stopped and held at that position. The magnitude of the tension to be applied can be appropriately changed depending on the magnitude of the movement amount. The magnitude of the tension to be applied (the magnitude of the amount of movement) can be appropriately selected within a range in which the long material 10 is not plastically deformed.

[Vibration applying process]
In the vibration applying step, the long material 10 to which a constant tension is applied in the longitudinal direction is damped and vibrated. First, an external force is applied to a part of the long material 10 (here, approximately the center). The direction in which the external force acts is a direction orthogonal to the longitudinal direction of the long material 10 as indicated by the black arrow. This external force may be a tensile force that pulls the long material 10 or a pressing force that presses the long material 10. By applying this external force, as shown in the third diagram from the left in FIG. 1, a part of the long material 10 is displaced in a direction perpendicular to the longitudinal direction. Next, when the amount of displacement of a part of the long material 10 reaches a predetermined amount, the applied external force is released. By doing so, as shown in the right diagram of FIG. 1, the long material 10 vibrates, and the vibration gradually attenuates and converges.

[Measurement process]
In the measurement step, a change in tension of the long material 10 that undergoes damped vibration is measured. The tension of the long material 10 measured in the vibration applying step becomes maximum when an external force is applied and a predetermined displacement amount (displacement amount is maximum). This tension gradually decreases as the vibration of the long material 10 is attenuated, and corresponds to a certain tension applied in the tensioning process when the vibration of the long material 10 converges. In the case of a general measuring method for measuring the displacement of the amplitude of the long material 10, when the long material 10 is damped and vibrated, the displacement + (plus) side and the displacement across the position before the vibration (displacement zero) The displacement is zero when the vibration converges repeatedly on the minus (minus) side. In contrast, in the method for measuring the attenuation coefficient of the long material according to the present embodiment, the tension of the long material 10 changes between the maximum tension and a constant tension before vibration, and is equal to or less than the constant tension (vibration). Less than the previous tension).

[Calculation process]
The calculation step calculates the attenuation coefficient of the long material based on the measurement result of the tension transition in the measurement step. Thereby, the convergence time of the tension transition in the long material 10 can be obtained from the tension transition obtained by the measurement process. Therefore, it can be seen how the long material 10 vibrates and how easily the vibration of the long material converges.

[Effects of the method for measuring the damping coefficient of long materials]
According to the method for measuring the attenuation coefficient of the long material according to the first embodiment, the attenuation coefficient can be calculated from the change in tension by simply causing the long material to dampen and vibrate in a state where a certain tension is applied to the long material. Therefore, it is easy to measure the attenuation coefficient of a long material.

<< Embodiment 2 >>
With reference to FIG. 2, the elongate material attenuation coefficient measuring apparatus according to Modification 1 will be described. The long material attenuation coefficient measuring apparatus according to the first modification is provided with a vibration applying mechanism 5 that attenuates and vibrates the long material 10 to which a constant tension is applied in the longitudinal direction. The difference from the coefficient measuring device 1 is the same as that of the long material attenuation coefficient measuring device 1 of the first embodiment except for the points. Hereinafter, the description will focus on the differences, and the description of the same configuration and the same effect will be omitted. In FIG. 2, for convenience of explanation, only a part of the vibration applying mechanism 5 and the long material 10 are shown.

[Attenuation coefficient measuring device for long materials]
[Vibration imparting mechanism]
The vibration applying mechanism 5 dampens and vibrates the long material 10 by applying an external force in a direction perpendicular to the longitudinal direction of the long material 10 to displace a part of the long material 10 and releasing the external force. Here, the vibration applying mechanism 5 includes a configuration capable of applying a pressing force that presses the long material 10, specifically, a rotating shaft portion 51 and a pressing portion 52.

(Rotating shaft)
The rotating shaft portion 51 rotates a later-described pressing portion 52 by rotating. One end of the rotation shaft portion 51 is a fixed end (base end) fixed integrally to a rotation mechanism (not shown). The other end of the rotating shaft portion 51 is a free end, and a pressing portion 52 is integrally fixed to the other end side. The axial direction of the rotating shaft portion 51 is parallel to the longitudinal direction of the long material 10. For example, a servo motor can be used as the rotation mechanism. The fixed end side of the rotating shaft 51 to which the motor of the rotating mechanism and the power of the motor are transmitted is attached to the pedestal 23 (FIG. 1).

(Pressing part)
The pressing unit 52 presses a part of the long material 10 in a direction orthogonal to the longitudinal direction of the long material 10. Thereby, a part of the long material 10 is displaced in a direction orthogonal to the longitudinal direction. Here, the pressing location of the pressing portion 52 is set at the approximate center of the long material 10. One end of the pressing portion 52 is integrally fixed to the rotation shaft portion 51 so as to be orthogonal to the rotation shaft of the rotation shaft portion 51. That is, the pressing part 52 rotates in conjunction with the rotation of the rotating shaft part 51 by the rotating mechanism. The other end side of the pressing portion 52 is a free end, and applies an external force to the long material 10 or releases the external force according to the amount of rotation of the rotating shaft portion 51.

  Specifically, the other end side of the pressing portion 52 is in the initial position indicated by the solid line (the long material 10 is in a state where an external force in a direction orthogonal to the longitudinal direction is not acting) on the long material 10. The long material 10 is pressed by the rotation. When the other end side of the pressing portion 52 is further rotated by the rotating shaft portion 51, the long material 10 is further pressed to increase the displacement amount of the long material 10. When the other end side of the pressing portion 52 is rotated to a predetermined range as indicated by a two-dot chain line by the rotating shaft portion 51, the displacement of the long material 10 is maximized. At this time, the tension of the long material 10 is maximized. When the other end side of the pressing part 52 is rotated beyond a predetermined range by the rotating shaft part 51 as shown by the right broken line, the contact with the long material 10 is released and the external force applied to the long material 10 is released. Immediately after the external force is released, the long member 10 moves from the position of the maximum displacement to the opposite side beyond the initial position as shown by the broken line on the left side. Thereafter, the long material 10 vibrates by the reaction, gradually attenuates and converges to the initial position. The rotation range from the contact with the long material 10 on the other end side of the pressing portion 52 to the release of the contact can be appropriately selected according to the length of the pressing portion 52 and the desired displacement amount of the long material 10. What is necessary is just to select suitably the length of the press part 52, the position of the rotating shaft part 51, etc. according to the rotation range.

  It is preferable that the vibration applying mechanism 5 further includes an expansion / contraction mechanism that changes the length of the rotation shaft portion 51. Then, the position of the pressing part 52 can be varied according to the length of the long material 10.

[Function and effect]
According to the long material damping coefficient measuring apparatus of the second embodiment, the long material 10 can be damped and vibrated by the vibration applying mechanism 5, so that adjustment of the external force applied to the long material is easy.

<< Test Example 1 >>
Using the long material attenuation coefficient measuring apparatus 1 described with reference to FIG. 1, the sample No. 1 in which the attenuation coefficient of the long material 10 was measured by the above-described long material attenuation coefficient measurement method. 1 and the sample No. 1 in which the damping vibration of the long material 10 was simulated using the measured damping coefficient. The result with 100 was compared. Waveforms of tension transition in each sample are shown in FIGS. 3 and 4, the horizontal axis represents time (s), and the vertical axis represents tension (N). 3 and 4, the time and tension from the time point when the external force to the long material 10 is released are shown.

  Sample No. As shown in FIG. 3, No. 1 shows the maximum value of the tension of the long material 10 at 19.82 s. Then, it can be seen that the external force to the long material 10 was released at the time of 19.82 s, the tension changed from that time, and converged to a constant tension at the time of about 19.97 s. That is, it can be seen that the vibration of the long material 10 starts at the time of 19.82 s, gradually attenuates from that time, and converges and stops at the time of about 19.97 s. Sample No. The time when the long material 10 of 1 converged to a constant tension (vibration stopped) was 0.15 s.

  Sample No. 100 shows the shape and size of the long material, the constant tension applied to the long material, and the maximum tension when the long material is displaced on the simulation software. 1 and sample no. The simulation was performed by setting the damping coefficient obtained from the change in tension of 1. The attenuation coefficient is the sample No. From the measurement result of 1, the time for convergence from the maximum tension to a constant tension was set to be 0.15 s. As a result, sample no. As shown in FIG. 4, the tension of 100 reached the maximum value at the time of 1 s, gradually decreased as time passed, and converged to a constant tension at the time of about 1.15 s. That is, sample no. The time to converge to a constant tension of 100 is the sample No. 1 and 0.15 s. When the waveforms of FIG. 3 and FIG. 4 are compared, the sample No. shown in FIG. The waveform of the change in tension of 100 is the sample No. shown in FIG. It can be seen that it substantially matches the waveform of 1.

  From this result, if the attenuation coefficient of the long material is measured by the above-described long material attenuation coefficient measuring method using the long material attenuation coefficient measuring apparatus 1 described with reference to FIG. It was found that the method of vibration of the material, the tension acting on the long material during vibration, the ease of convergence of the vibration, etc. can be grasped by simulation.

  The long material attenuation coefficient measuring apparatus and the long material attenuation coefficient measuring method of the present invention can be suitably used for measuring the attenuation coefficient of a long material.

DESCRIPTION OF SYMBOLS 1 Long material damping coefficient measuring device 10 Long material 2 Tension applying mechanism 21a, 21b Gripping part 22 Moving mechanism 23 Base part 3 Tension measuring part 4 Arithmetic processing part 40 Monitor 5 Vibration applying mechanism 51 Rotating shaft part 52 Pressing part

Claims (3)

A tension applying mechanism that holds both ends of the long material and applies a constant tension in the longitudinal direction of the long material;
A tension measuring unit that measures a change in tension of the long material when the long material to which a constant tension is applied in the longitudinal direction vibrates and oscillates;
A long material attenuation coefficient measuring apparatus comprising: an arithmetic processing unit that calculates an attenuation coefficient of the long material based on a measurement result of the tension measuring unit.   By applying an external force in a direction perpendicular to the longitudinal direction to a part of the long material to which a constant tension is applied in the longitudinal direction, displacing a part of the long material, and releasing the external force The long-material attenuation coefficient measuring apparatus according to claim 1, further comprising a vibration applying mechanism that attenuates and vibrates the long material. A tensioning step for applying a constant tension in the longitudinal direction of the long material;
A vibration applying step of damping and vibrating the long material to which a constant tension is applied in the longitudinal direction;
A measurement process for measuring a change in tension of the long material that oscillates damped;
A long material attenuation coefficient measurement method comprising: a calculation step of calculating an attenuation coefficient of the long material based on a measurement result in the measurement step.

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