JP2016206018A - Device for measuring humidity exhaust deformation amount - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure the humidity exhaust deformation amounts of a plurality of test pieces at the same time.SOLUTION: A humidity exhaust deformation amount measurement device 1 comprises: a test piece set unit 20 in which a plurality of previously moisture-absorbed test pieces 21 and a reference piece 22 are set; a dry box 10 having a plurality of laser interferometers 60, each of which is disposed face to face on each individual test piece 21 and one end face E1 of the reference piece 22; and a laser beam emission device 40 disposed on the outside of the dry box 10. A light passage part 10A is formed in the wall part 10W of the dry box 10, and there are provided inside the dry box 10 a light branching optical system 50 for branching a laser beam L and making it incident on each individual laser interferometer 60, a plurality of first mirrors 31 each of which is fitted to each individual test piece 21 and one end face E1 of the reference piece 22, and a plurality of second mirrors 32 each of which is fitted to each individual test piece 21 and the other end face E2 of the reference piece 22.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an apparatus for measuring a deformation amount of exhaust moisture.

  Composite materials such as carbon fiber reinforced plastic (CFRP) are widely used as materials that are lightweight, rigid, and have a small amount of thermal deformation in space equipment or structures mounted on artificial satellites or the like. On the other hand, such a composite material tends to change in length and mass due to moisture adsorption (absorption) in the air.

In the case of a structure for space, moving from a normal humidity environment on the ground to a 0% humidity environment in space can cause the structure to undergo moisture deformation and reduce the accuracy of the on-board equipment.
Therefore, it is preferable to be able to predict the accuracy change due to the moisture deformation. In addition, it is preferable to measure the amount of deformation with respect to a plurality of test pieces, and select one having a relatively small amount of deformation with respect to the exhaust.

Conventionally, there is no technique for directly measuring the amount of moisture deformation, but instead, a technique for measuring the amount of moisture deformation during the process of absorbing moisture in a constant temperature and humidity chamber for a test piece dried at high temperature has been adopted. Yes.
For example, Patent Document 1 discloses a deformation amount measuring apparatus capable of measuring a moisture absorption deformation amount of a composite material or the like (Claim 1, Abstract, FIG. 1, etc.).
This deformation amount measuring device includes a laser interferometer (9) and a test piece storage device (12) installed facing the laser interferometer (9) in a constant temperature and humidity chamber (14). The storage device (12) includes a flat half mirror (4) and a flat mirror (3) connected by a spring (5) so that the mirror surface faces the flat half mirror (4).
In this deformation amount measuring apparatus, the displacement due to moisture absorption deformation of the test piece (1) is reflected in the positional relationship between the plane mirror (3) and the plane half mirror (4), and the reflected light of the plane mirror (3) and the plane half mirror The amount of deformation of the test piece (1) can be measured by measuring the amount of interference fringe change caused by the interference with the reflected light in (4) with the laser interferometer (9).

JP 2005-017134 A

  The prior art described in Patent Document 1 or the like that measures the moisture absorption deformation amount of a test piece dried at a high temperature needs to completely dry the test piece before measurement, and starts measurement immediately before moisture absorption immediately after complete drying. The measurement setting is very difficult because it is necessary.

  In the prior art, one of the reasons for measuring the amount of moisture absorption deformation is that a laser head that emits laser light used in a laser interferometer cannot be used in a 0% humidity environment.

Further, an environment with a humidity of 0% can be generated by evacuating the measurement space, but measurement under vacuum has the following problems.
A general measuring instrument such as a laser interferometer cannot be used under vacuum.
Moreover, although the progress degree of moisture removal can be confirmed by measuring the mass of the coupon piece of the same material as a test piece, mass measurement is difficult under vacuum.
Furthermore, vibrations such as a compressor or a turbo molecular pump used to evacuate the measurement space may adversely affect the measurement data.

Moreover, in order to improve measurement efficiency, it is preferable that a single measuring device can be used to simultaneously measure a plurality of test pieces.
Patent Document 1 discloses a technique for moving a laser interferometer or a test piece on a guide rail (13) with a precision positioning mechanism as a technique for simultaneously measuring a plurality of test pieces (Embodiment 2). , FIG. 4 etc.). However, in this technique, it is difficult to control the movement and position of the laser interferometer or the test piece on the guide rail by the precision positioning mechanism, the apparatus configuration is complicated, the cost is high, and high precision measurement is difficult. In addition, the number of test pieces that can be measured with a laser interferometer at a certain timing is one, and continuous measurement with a laser interferometer cannot be performed for each test piece.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a dehumidification deformation amount measuring apparatus capable of simultaneously measuring the dehumidification deformation amounts of a plurality of test pieces.

The dehumidification deformation measuring device of the present invention is
A dehumidification deformation measuring device for measuring the dehumidification deformation of a plurality of test pieces,
Inside, a plurality of test pieces set in advance and a test piece set part in which a reference piece is set, and a plurality of laser interferometers, each of which is arranged to face one end face of each of the test piece and the reference piece A dry box having
A laser beam emitting device disposed outside the dry box;
On the wall portion of the dry box, a light passage portion that guides the laser light emitted from the laser light emitting device to the inside of the dry box is formed,
A light branching optical system for branching the laser light incident on the inside of the dry box through the light passing portion into the inside of the dry box and entering each of the laser interferometers, and each test piece and A plurality of first mirrors attached to one end face of the reference piece, and a plurality of second mirrors each attached to the individual test piece and the other end face of the reference piece,
The laser interferometer detects interference fringes between the first reflected light reflected by the first mirror and the second reflected light reflected by the second mirror.

  ADVANTAGE OF THE INVENTION According to this invention, the exhaust-humidity deformation measuring apparatus which can measure the exhaust-humidity deformation of several test pieces simultaneously can be provided.

It is a principal part top view of the exhaust-humidity deformation measuring device of one embodiment concerning the present invention. It is a flowchart which shows operation | movement of the moisture displacement measuring device of FIG. It is a graph which shows the example of measurement data.

With reference to the drawings, a description will be given of a configuration of a moisture displacement measuring apparatus according to an embodiment of the present invention.
FIG. 1 is a top view of the main part of the apparatus for measuring the amount of deformation of exhaust moisture according to the present embodiment.
In this figure, the inside of the dry box is shown in a perspective view.

The moisture displacement measurement apparatus 1 according to this embodiment includes a dry box 10.
The dry box 10 is an openable / closable box including a box body having an opening on the upper surface and a lid member that closes the opening on the upper surface of the box body (not shown).
In the closed state, the dry box 10 can be controlled to a constant internal humidity of 0%.
The method for reducing the humidity inside the dry box 10 to 0% is not particularly limited, and examples include a method of dehumidifying using a desiccant or the like.

The dry box 10 includes a test piece setting unit 20 in which a plurality of test pieces 21 and a reference piece 22 are set.
The test piece 21 and the reference piece 22 are rod-shaped pieces extending from one end surface (the left end surface in the drawing) E1 to the other end surface (the right end surface in the drawing) E2.
The material of the test piece 21 is not particularly limited, and examples thereof include a composite material such as carbon fiber reinforced plastic (CFRP).
The test piece 21 is a moisture absorption piece stored in advance under a certain humidity.
The number of test pieces 21 that can be measured at one time is not particularly limited, and is six in the illustrated example.
The reference piece 22 is a rod-like piece having the same length as that of the test piece 21 and is made of a material that does not cause moisture exhaustion deformation and temperature deformation, and is made of a material such as zero expansion glass and quartz.
One reference piece 22 is sufficient.

  The dry box 10 has a plurality of laser interferometers 60 disposed inside the dry box 10 so as to face each of the individual test pieces 21 and the one end face E1 of the reference piece 22.

The moisture displacement measurement apparatus 1 according to the present embodiment includes a laser beam emitting device 40 disposed outside the dry box 10.
As the laser beam emitting device 40, a known laser such as a He—Ne laser (wavelength: 633 nm) can be used.
In the figure, reference numeral 41 denotes a laser head of the laser beam emitting device 40.
In this embodiment, the laser beam emitting device 40 including the laser head 41 prevents the laser head 41 itself from being affected by the exhaust moisture of the dry box 10, and the heat generated by the laser head 41 itself affects the measurement in the dry box 10. Is arranged outside the dry box 10.

  In the present embodiment, a light passage portion 10 </ b> A that guides the laser light L emitted from the laser light emitting device 40 to the inside of the dry box 10 is formed on the wall portion 10 </ b> W of the dry box 10. In one aspect, the light passage portion 10A is a through hole through which the laser light L passes.

Inside the dry box 10, there is provided a light branching optical system 50 that branches the laser light L that has entered the inside of the dry box 10 through the light passage portion 10 </ b> A and enters each laser interferometer 60.
In the present embodiment, the light branching optical system 50 is an optical system including a plurality of beam splitters 51.
Each beam splitter 51 includes a half mirror that reflects a part of incident light by 90 ° and transmits the remaining light.

In the present embodiment, the first mirror 31 is attached to one end surface E <b> 1 of each test piece 21 and reference piece 22. A second mirror 32 is attached to each of the other end surfaces E2 of the individual test pieces 21 and the reference pieces 22.
Even if the length of the test piece 21 changes, the first mirror 31 attached to the test piece 21 always contacts the one end surface E1 without a gap.
Even if the length of the test piece 21 changes, the second mirror 32 attached to the test piece 21 always contacts the one end surface E2 without a gap.
A method for storing the plurality of test pieces 21 and the reference pieces 22 in the test piece set unit 20 and a method for attaching the first mirror 31 and the second mirror 32 to the test pieces 21 and the reference pieces 22 are not particularly limited, and are publicly known methods. Can be applied.

In order to correct the measurement value obtained by the laser interferometer 60, an environmental sensor 71 for measuring at least one environmental condition such as temperature, humidity, and atmospheric pressure is set inside the dry box 10. The
The environmental sensor 71 is preferably one that measures all of temperature, humidity, and atmospheric pressure.
The reference piece 22 having the same length as that of the test piece 2 is a standard sample, and is used to confirm that the correction is correctly performed.

Each laser interferometer 60 includes a first reflected light R1 reflected by the first mirror 31 attached to one end surface E1 of the corresponding test piece 21 or reference piece 22, and the corresponding test piece 2 or reference piece 22. An interference fringe with the second reflected light R2 reflected by the second mirror 32 attached to the end face E2 is detected.
Each laser interferometer 60 arranged to face each test piece 21 obtains the optical path difference between the first reflected light R1 and the second reflected light R2 from the interference fringes, and the length of the corresponding test piece 21 and its displacement amount. (Humidity deformation amount) can be obtained.
In the present embodiment, the measurement of the amount of moisture deformation of each test piece 21 by each laser interferometer 60 is preferably performed continuously over time.

  In order to confirm the correction of the measurement value by the laser interferometer 60, the measurement by the laser interferometer 60 can be performed on the reference piece 22 as necessary, similarly to the test piece 21. Note that the measurement of the reference piece 22 by the laser interferometer 60 is performed in advance before the measurement of the plurality of test pieces 21 is started.

Using a measuring device such as a capacitance sensor different from the laser interferometer, one end surface E2 of the test piece 21 is brought into contact with the fixed surface of the measuring device, and the deformation amount is measured based only on the change of the other end surface E1. In such a case, a measurement error may occur due to a dimensional change in the constituent elements of the measuring apparatus due to an influence of a temperature change or the like.
On the other hand, in the configuration of the present embodiment in which the deformation amount is measured using the first reflected light R1 reflected by the first mirror 31 and the second reflected light R2 reflected by the second mirror 32, the measurement apparatus Even if a dimensional change occurs in the components, there is no effect on the measurement data.

The moisture deformation measurement apparatus 1 of the present embodiment is made of the same material as the test piece 21, and the coupon piece 73, which is a hygroscopic piece stored under the same humidity as the test piece 21, is subjected to mass reduction due to moisture loss over time. In particular, it is preferable that the measurement can be performed continuously.
For example, a mass meter 72 such as an electronic balance is set inside the dry box 10, a coupon piece 73 made of the same material as the test piece 21 is placed on the mass meter 72, and a coupon piece 73 due to moisture loss from the coupon piece 73. It is preferable to measure the decrease in the mass over time, preferably continuously. With such a configuration, it is possible to monitor the progress of moisture removal, which is preferable.

  In the moisture displacement measurement apparatus 1 of the present embodiment, the dry box 10 is subjected to vibration isolation in order to block external vibrations and reduce the influence of disturbance on the laser interferometer 60 and obtain highly accurate measurement data. It is preferably installed on the surface plate 80.

In the moisture displacement measurement apparatus 1 of this embodiment, the measurement data measured by the laser interferometer 60 and the measurement data measured by the mass meter 72 are automatically sent to the recording device 90 arranged outside the dry box 10. Is recorded and stored, and data processing is performed as required by the operator.
An example of the recording device 90 is an information processing device such as a personal computer.
The measurement data is automatically recorded and saved on a hard disk or a recording medium in the recording device 90.

With reference to the drawings, the operation of the moisture displacement measuring apparatus 1 of the present embodiment will be described.
FIG. 2 is a flowchart showing the operation of the exhaust moisture change measuring device 1 of the present embodiment.

In advance, the measurement value by the laser interferometer 60 is corrected using the environmental sensor 71 and the reference piece 22 as necessary.
First, the lid of the dry box 10 is opened, and a plurality of test pieces 21 that are moisture absorption pieces stored at a constant humidity are set in the test piece setting unit 20 inside the dry box 10 (step S1).
Separately, a coupon which is preferably a moisture absorption piece made of the same material as the plurality of test pieces 21 and stored under the same humidity as the plurality of test pieces 21 on the mass meter 72 installed inside the dry box 10. The piece 73 is set (step S2).
Step S1 and step S2 are in no particular order.

Next, measurement and data recording are started (step S3).
Specifically, the laser beam L is emitted from the laser beam emitting device 40, and the length of each test piece 21 and its displacement amount (humidity deformation amount) are measured with the laser interferometer 60, preferably continuous measurement. Start.
At the same time, the time measurement of the mass of the coupon piece 73 by the mass meter 72 and its displacement amount, preferably continuous measurement, is started.
Measurement data obtained by the laser interferometer 60 and the mass meter 72 is automatically recorded and stored in a hard disk or a recording medium in the recording device 90.

Next, the lid material of the dry box 10 is closed, and moisture exhaustion is started (step S4).
The measurement data from the laser interferometer 60 and the measurement data from the mass meter 72 are recorded and stored at regular time intervals (step S5).
For example, the recording storage time interval is preferably 1 to 30 minutes.

The operator confirms the data measured by the mass meter 72 at the appropriate time and confirms whether the mass of the coupon piece 73 is sufficiently stable (step S6).
When it is determined that the mass of the coupon piece 73 is not sufficiently stable, the measurement by the laser interferometer 60 and the mass meter 72 and the data recording storage of these measurements are continued.
When it is determined that the mass of the coupon piece 73 is sufficiently stable, the recording and storing of the measurement data are stopped, and the measurement is ended (step S7).
An example of measurement data is shown in FIG.

In the exhaust moisture deformation measuring device 1 of the present embodiment, the plurality of test pieces 21 are set inside the dry box 10 in which the internal humidity can be controlled to be 0%.
In the dehumidification deformation measuring apparatus 1 of the present embodiment, the laser interferometer 60 is disposed inside the dry box 10, and includes a laser head 41 that emits a laser beam L used for measurement by the laser interferometer 60. The emission device 40 is disposed outside the dry box 10.

In general, the laser interferometer 60 cannot be used under vacuum, but the laser interferometer 60 can be used without any problem by using the dry box 10 for generating a 0% humidity environment.
In general, the laser head 41 cannot be used in an environment of 0% humidity, but the laser head 41 can be used without any problem by disposing the laser head 41 outside the dry box 10.
As described above, in this embodiment, it is possible to measure the amount of deformation due to moisture using a general optical instrument.

In the prior art described in Patent Document 1 and the like, it is necessary to completely dry the test piece before measurement, and it is necessary to start measurement immediately before moisture absorption immediately after complete drying. Therefore, measurement setting is very difficult. .
On the other hand, in this embodiment, the test piece 21 does not need to be completely dried before measurement, and the inside of the dry box 10 may be a normal indoor environment until the start of dehumidification. There is no limit on setting time.

The laser light L emitted from the laser light emitting device 40 enters the dry box 10 through the light passage portion 10A provided on the wall portion 10W of the dry box 10.
Then, the laser light L incident on the inside of the dry box 10 through the light passing portion 10A is branched by the optical branching optical system 50 in accordance with the number of the plurality of test pieces 21 and reference pieces 22, and is supplied to each laser interferometer 60. Incident.
In the present embodiment, Embodiment 2 of Patent Document 1 using a guide rail with a precision positioning mechanism. Unlike the configuration described in 1), it is possible to simultaneously measure a plurality of test pieces 21 without requiring a complicated and expensive apparatus configuration.
In the present embodiment, Embodiment 2 of Patent Document 1 using a guide rail with a precision positioning mechanism. Unlike the configuration described in (1), continuous measurement by the laser interferometer 60 can be performed on all the test pieces 21.

In the present embodiment, the mass meter 72 is installed inside the dry box 10 and the mass measurement of the coupon piece 73 is performed at the same time, so that the progress of the dehumidification can be confirmed in a timely manner. Thereby, the time required for moisture removal can be confirmed, and the timing of the end of measurement can be determined appropriately.
In addition, under vacuum, although it is difficult to measure the mass of the coupon piece 73 of the same material as the test piece 21, in this embodiment, the mass measurement of the coupon piece 73 is simply performed by using the dry box 10. can do.

  Normally, complete dehumidification of a composite material such as carbon fiber reinforced plastic (CFRP) takes several months, but the total dehumidification time is predicted from the transition of the mass change of the coupon piece 73 and dehumidified before complete dehumidification. It is also possible to shorten the measurement time by estimating the deformation amount.

  In the present embodiment, by installing the dry box 10 on the vibration isolation surface plate 80, it is possible to block external vibrations and obtain highly accurate measurement data.

By using the moisture displacement measuring apparatus 1 of the present embodiment, for example, a composite material such as carbon fiber reinforced plastic (CFRP) when moving from a normal humidity environment on the ground to a humidity 0% environment in outer space can be used. The amount of moisture deformation can be measured.
According to the present embodiment, for example, simultaneous measurement can be performed on a plurality of test pieces 21 that have absorbed moisture under the same environment, and the difference in the amount of deformation in exhaust can be compared.
According to the present embodiment, for example, it is possible to perform measurement on a plurality of test pieces 21 that are greater than or equal to the required number, and to select the required number of test pieces 21 that have a relatively small amount of deformation of exhaust moisture.
According to the present embodiment, for example, it is possible to perform measurement on a plurality of test pieces 21 that are equal to or greater than the required number, and to select the required number of test pieces 21 that are close to the amount of moisture deformation.

  As described above, according to the present embodiment, it is possible to provide the moisture displacement measuring apparatus 1 that can simultaneously measure the moisture displacement amount of the plurality of test pieces 21.

(Design changes)
The present invention is not limited to the above-described embodiment, and design changes can be made as appropriate without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Dehumidification deformation measuring apparatus 10 Dry box 10A Light passage part 10W Wall part 20 Test piece set part 21 Test piece 22 Reference piece 31 First mirror 32 Second mirror 40 Laser light emitting device 41 Laser head 50 Optical branching optical system 51 Beam splitter 60 Laser interferometer 71 Environmental sensor 72 Mass meter 73 Coupon piece 80 Anti-vibration surface plate 90 Recording device E1 One end face E2 The other end face L Laser light R1 First reflected light R2 Second reflected light

Claims (4)

A dehumidification deformation measuring device for measuring the dehumidification deformation of a plurality of test pieces,
Inside, a plurality of test pieces set in advance and a test piece set part in which a reference piece is set, and a plurality of laser interferometers, each of which is arranged to face one end face of each of the test piece and the reference piece A dry box having
A laser beam emitting device disposed outside the dry box;
On the wall portion of the dry box, a light passage portion that guides the laser light emitted from the laser light emitting device to the inside of the dry box is formed,
A light branching optical system for branching the laser light incident on the inside of the dry box through the light passing portion into the inside of the dry box and entering each of the laser interferometers, and each test piece and A plurality of first mirrors attached to one end face of the reference piece, and a plurality of second mirrors each attached to the individual test piece and the other end face of the reference piece,
The laser interferometer detects interference fringes between the first reflected light reflected by the first mirror and the second reflected light reflected by the second mirror;
Dehumidification deformation measuring device. In addition, the dry box was further preliminarily moisture-absorbed under the same conditions as the test piece, and provided with a mass meter for measuring the mass of the coupon piece of the same material as the test piece.
The exhaust-humidity deformation measuring apparatus according to claim 1. The dry box was placed on a vibration isolation platen,
The exhaust-humidity deformation measuring device according to claim 1 or 2. And a recording device for recording data measured by the laser interferometer.
The exhaust-humidity deformation measuring device according to any one of claims 1 to 3.

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