Instrument for measuring coefficient of linear expansion

Abstract

To provide an instrument and method for measuring a coefficient of linear expansion with which the coefficient of linear expansion of a target material can be easily measured with the use of a simple device.SOLUTION: Provided is a method for measuring the coefficient of linear expansion of an object attached with an instrument for measuring a coefficient of linear expansion 1, the instrument for measuring a coefficient of linear expansion 1 having a sensitive part 3 with a coefficient of linear expansion βs of 0 or more and 0.5×10-6 / °C or less, the method including the steps of: obtaining a first thermal output value εapp1 that is the thermal output value of an object at a first temperature T1; obtaining a second thermal output value εapp2 that is the thermal output value of the object at a second temperature T2; and determining the coefficient of linear expansion of the object from βs=(εapp2-εapp1) / (T2-T1) by using the first temperature, first thermal output value, second temperature, and second thermal output value.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an instrument for measuring the coefficient of linear expansion. [Background technology]

[0002] Japanese Patent Application Laid-Open No. 2021-063776 describes a linear expansion coefficient measuring device. This linear expansion coefficient measuring device is a large-scale device that requires a thermostat.

[0003] JP 2020-106274 A describes a strain gauge that can be used to measure the strain of a target material.

[0004] JP 2020-1271 A describes a thermal expansion measuring device that uses a strain gauge. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-063776 [Patent Document 2] Patent Publication No. 2020-106274 [Patent Document 3] JP 2020-1271 A Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide an apparatus and method for measuring the linear expansion coefficient that can easily measure the linear expansion coefficient of a target material using a simple device. [Means for solving the problem]

[0007] This invention is based on the finding that the linear expansion coefficient of a material can be easily obtained by using a strain gauge designed for a non-elastic material to measure the change in thermal output of a stretchable material with temperature.

[0008] The first invention relates to a linear expansion coefficient measuring device 1. The linear expansion coefficient measuring device is a device for measuring the linear expansion coefficient of an object. This linear expansion coefficient measuring device has a sensing part 3. The linear expansion coefficient of the sensing part 3 is expressed as β s Then, β s is 0 or more than 0.5×10 -6 / ℃ or less.

[0009] The second invention relates to a method for measuring the linear expansion coefficient of an object, in which the above-mentioned linear expansion coefficient measuring device 1 is attached to the object. and obtaining a first heat output value, the heat output value of the object at the first temperature; obtaining a second heat output value, the second heat output value being a heat output value of the object at a second temperature; and determining a linear expansion coefficient of the object using the first temperature, the first heat output value, the second temperature, and the second heat output value.

[0010] The step of determining the linear expansion coefficient of the object may, for example, be performed by calculating the first temperature, the second temperature, the first heat output value, the second heat output value, and the linear expansion coefficient of the object as T1, T2, ε app1 , ε app2 And, β s Then, β s =(ε app2 -ε app1 This is the process of calculating the linear expansion coefficient of the object by (T2-T1).

[0011] The third invention relates to a system for measuring a linear expansion coefficient. This system measures a linear expansion coefficient of an object to which a linear expansion coefficient measuring device 1 is attached, from the linear expansion coefficient measuring device 1, a first heat output value acquisition unit 11 that acquires a first heat output value, which is a heat output value of an object at a first temperature; a second heat output value acquisition unit 13 that acquires a second heat output value, which is a heat output value of the object at a second temperature; and a linear expansion coefficient calculation unit 15 that calculates the linear expansion coefficient of the object using the first temperature, the first heat output value, the second temperature, and the second heat output value.

[0012] A fourth aspect of the present invention relates to a program for causing a computer to perform a calculation to determine the linear expansion coefficient of an object. This program is executed by a computer connected to the linear expansion coefficient measuring device 1. For the object on which the linear expansion coefficient measuring device 1 is attached, obtaining a first heat output value, the first heat output value being a heat output value of the object at a first temperature; obtaining a second heat output value, the second heat output value being a heat output value of the object at a second temperature; and determining the linear expansion coefficient of the object using the first temperature, the first thermal output value, the second temperature, and the second thermal output value. Effect of the Invention

[0013] According to the present invention, it is possible to provide a linear expansion coefficient measuring device and a measuring method that can easily measure the linear expansion coefficient of a target material using a simple device. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a conceptual diagram for explaining a measuring device and a measuring system for a linear expansion coefficient. [Diagram 2] FIG. 2 is a conceptual diagram of a strain gauge. [Diagram 3] FIG. 3 is a graph, instead of a drawing, showing the relationship between temperature (horizontal axis) and the strain (apparent strain) generated when the strain gauge of Example 1 was attached to a non-elastic material. [Figure 4] FIG. 4 is a conceptual diagram of the experimental system in Example 2. [Diagram 5]FIG. 5 is a graph, instead of a drawing, showing the relationship between temperature (horizontal axis) and strain (apparent strain) caused by temperature when an aluminum material is used as the measurement target material in Example 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, the embodiments for carrying out the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments described below, and includes appropriate modifications of the embodiments described below within the scope obvious to those skilled in the art.

[0016] FIG. 1 is a conceptual diagram for explaining a linear expansion coefficient measuring device and a linear expansion coefficient measuring system. The first invention relates to a linear expansion coefficient measuring device 1. A linear expansion coefficient measuring device is a device for measuring the linear expansion coefficient of an object. This linear expansion coefficient measuring device is attached to the object and can measure (estimate) the linear expansion coefficient of the object by measuring the thermal output when the temperature is changed. This linear expansion coefficient measuring device 1 has a sensing part 3. The linear expansion coefficient of the sensing part 3 is expressed as β s Then, β s is 0 or more than 0.5×10 -6 / °C or less. The sensing part 3 is a part that is attached to an object. The linear expansion coefficient measuring device 1 measures the temperature of the sensing part 3 and the heat output from the sensing part 3. The linear expansion coefficient measuring device 1 may have the shape of a known strain gauge (for example, JP 2020-106274 A).

[0017] β s is 0 or more than 0.5×10 -6 A strain gauge having a sensing part 3 with a resistance temperature coefficient of α or less is usually adjusted to match the linear expansion coefficient of the apparently non-elastic material to be measured, and is a strain gauge with a small apparent strain with respect to the non-elastic material to be measured. s In order to adjust the linear expansion coefficient, it is necessary to adjust the type of alloy, the shape of the alloy, the heating and annealing conditions of the alloy, etc. This linear expansion coefficient measuring device 1 is within the self-temperature compensation range (β s The absolute value of is 0 or more and 0.5 × 10 -6 / ℃ or less, preferably 0.4×10 -6 / ℃ or less, more preferably 0.3×10 -6 / ℃ or less, more preferably 0.2×10 -6 The self-temperature compensation range varies depending on the sensing unit 3. An example of the self-temperature compensation range is 10°C to 100°C.

[0018] The object is an object whose linear expansion coefficient is to be determined (estimated) using the linear expansion coefficient measuring device 1. The object may be any object whose linear expansion coefficient is to be measured. Examples of the object include β s is 1×10 -6 / ℃ or more (2×10 -6 / ℃ or more, 3×10 -6 / ℃ or more, 4×10 -6 / °C or higher). The linear expansion coefficient of an object can be roughly estimated based on its material (elastic material), etc.

[0019] The second invention relates to a method for measuring the linear expansion coefficient of an object, in which the above-mentioned linear expansion coefficient measuring device 1 is attached to the object. A first heat output value is then obtained, which is the heat output value of the object at the first temperature. A second heat output value is obtained, the heat output value of the object at the second temperature. The first temperature, the first heat output value, the second temperature, and the second heat output value are used to determine a linear expansion coefficient of the object. It is preferable that the first temperature and the second temperature are both within the self-temperature compensation range. It is preferable that the first temperature and the second temperature are apart by 5°C or more (preferably 10°C or more, more preferably 20°C or more).

[0020] For example, the first temperature, the second temperature, the first heat output value, the second heat output value, and the linear expansion coefficient of the object are T1, T2, ε app1 , ε app2 And, β s Then, β s =(ε app2 -ε app1The linear expansion coefficient of the object can be calculated by (T2-T1) / (T2-T1).

[0021] The third invention relates to a system for measuring a linear expansion coefficient, which is a system for performing various calculations using a computer.

[0022] The computer has an input unit, an output unit, a control unit, a calculation unit, and a storage unit, and each element is connected by a bus or the like so as to be able to exchange information. For example, the storage unit may store a control program or various information. When predetermined information is input from the input unit, the control unit reads out the control program stored in the storage unit. Then, the control unit appropriately reads out the information stored in the storage unit and transmits it to the calculation unit. Also, the control unit appropriately transmits the input information to the calculation unit. The calculation unit performs calculation processing using the various information received and stores it in the storage unit. The control unit reads out the calculation result stored in the storage unit and outputs it from the output unit. In this way, various processes and each process are executed. The various units and means execute these various processes. The computer may have a processor, and the processor may realize various functions and various processes. The computer may be standalone. A part of the functions of the computer may be distributed between a server and a terminal. In that case, it is preferable that the server and the terminal are able to exchange information through a network such as the Internet or an intranet. A computer may include a processor and a memory coupled to the processor, the memory storing instructions that, when executed by the processor, cause the computer to perform various processes or function as various components.

[0023] The computer may be provided with various teaching data to construct a learning model and realize various calculations by machine learning. In this case, the computer may execute various analyses using a learning model created by machine learning and deep learning of AI (artificial intelligence). For example, the computer uses an accurate measuring device to obtain the linear expansion coefficient of the object to be measured, and sets this as the correct answer data. Then, it obtains each temperature and heat output value for the object. It is also possible to construct a learning model using these data as teaching data, and to determine whether the linear expansion coefficient can be obtained approximately from the heat output values ​​for several temperatures. In this way, it is possible to determine whether the linear expansion coefficient of the object can be obtained. Of course, it is also possible to construct a learning model that obtains the linear expansion coefficient from several temperatures and heat output values, and obtain the linear expansion coefficient of the object by inputting multiple temperatures and measured heat output values ​​into the learning model.

[0024] The above system includes a first heat output value acquisition unit 11, a second heat output value acquisition unit 13, and a linear expansion coefficient calculation unit 15. The first heat output value acquisition unit 11 and the second heat output value acquisition unit 13 are conceptual elements, and the same physical element may actually implement both functions. The first heat output value acquisition unit 11 is an element for obtaining a first heat output value, which is a heat output value of an object at a first temperature, from the linear expansion coefficient measurement device 1 for an object to which the linear expansion coefficient measurement device 1 is attached. The second heat output value acquisition unit 13 is an element for obtaining a second heat output value, which is a heat output value of an object at a second temperature, from the linear expansion coefficient measurement device 1 for an object to which the linear expansion coefficient measurement device 1 is attached.

[0025] The measuring device 1 adjusts the temperature of a heater or the like attached to the sensory unit 3, observes the heat output from the sensory unit 3, and outputs the obtained temperature and heat output values ​​to the system 1. The system may also adjust the temperature of a heater or the like attached to the sensory unit 3, and observe the heat output from the sensory unit 3. The temperature and heat output values ​​input to the input unit of the system are appropriately stored in the memory unit and used for various calculations.

[0026] The linear expansion coefficient calculation unit 15 is an element for calculating the linear expansion coefficient of the object using the first temperature, the first heat output value, the second temperature, and the second heat output value. The first temperature, the second temperature, the first heat output value, the second heat output value, and the linear expansion coefficient of the object are defined as T1, T2, ε app1 , ε app2 And, β s Then, β s =(ε app2 -ε app1 For example, the linear expansion coefficient calculation unit 15 can obtain the linear expansion coefficient of the object by calculating T1, T2, ε app1 , and ε app2 and calculate (ε app2 -ε app1 In this manner, the linear expansion coefficient calculation unit 15 calculates the linear expansion coefficient β of the object. s The linear expansion coefficient β of the object can be calculated. s may be appropriately stored in the storage unit, may be displayed on the display unit, or may be output by printing or the like. In addition, the linear expansion coefficient calculation unit 15 adds T1, T2, ε app1 , and ε app2 Enter the linear expansion coefficient β of the target object. s Alternatively, a third heat output value at a third temperature may be calculated, and these values ​​may be input to the learning model to calculate whether the object has a linear expansion coefficient β s You may also check whether the person is eligible to receive the required service.

[0027] The above system can determine the linear expansion coefficient of an object by a process including the steps of obtaining a first thermal output value, which is the thermal output value of the object at a first temperature, obtaining a second thermal output value, which is the thermal output value of the object at a second temperature, and determining the linear expansion coefficient of the object using the first temperature, the first thermal output value, the second temperature, and the second thermal output value.

[0028] The fourth invention relates to a program for making a computer perform a calculation to obtain the linear expansion coefficient of an object. This program causes a computer connected to the linear expansion coefficient measuring device 1 to execute the following steps for an object to which the linear expansion coefficient measuring device 1 is attached: obtaining a first heat output value, which is a heat output value of the object at a first temperature, from the linear expansion coefficient measuring device 1; obtaining a second heat output value, which is a heat output value of the object at a second temperature; and obtaining the linear expansion coefficient of the object using the first temperature, the first heat output value, the second temperature, and the second heat output value. This specification also describes a non-transitory information recording medium that can be read by a computer that stores such a program. Examples of the information recording medium are a hard disk, a USB, a CD-ROM, a DVD, and an SSD. EXAMPLES

[0029] In this embodiment, the linear expansion coefficient β s -0.5×10 -6 / ℃~+0.5×10 -6 A strain gauge 20 suitable for a material having a temperature of 100° C. / ° C. was manufactured. This strain gauge 20 serves as a measuring device for the linear expansion coefficient. The shape of the strain gauge is publicly known, for example, as shown in Design Registration Nos. 1593195, 143184, and 1431583.

[0030] FIG. 2 is a conceptual diagram of a strain gauge 20. FIG. 2(a) is a front view, and FIG. 2(b) is a side view. The strain gauge 20 includes a nickel-chromium alloy 22 (with a linear expansion coefficient β g =13~14×10 -6A foil material having a resistance temperature of 1000 ppm / °C was used. The nickel-chromium alloy was annealed at 330-350°C for 6-10 hours, and then slowly cooled at room temperature for 3-4 hours. In this way, the resistance temperature coefficient α of the nickel-chromium alloy 22 between 10 and 100°C was adjusted to be 25-28 ppm / °C. The nickel-chromium alloy 22 was attached to a polyimide resin base 25 having a thickness of 15-30 μm. The strain gauge obtained in this way is an electric resistance type. The attached nickel-chromium alloy 22 and the polyimide resin 25 were etched with a ferric chloride solution, and the nickel-chromium alloy 22 was finished into a shape having a gauge resistance value of 120-350 Ω. A plated copper wire (which may be an enameled wire) 26 having a diameter of 0.10-0.18 mm was soldered 24 to the gauge tab 23. A polyester film (which may be a polyimide film) 21 having a thickness of 12-25 μm was formed on the surface of the nickel-chromium alloy 22 as a surface protection layer.

[0031] FIG. 3 shows the strain gauge 20 of Example 1 with a linear expansion coefficient β s =0×10 -6 1 is a graph in place of a drawing showing the relationship between temperature (horizontal axis) and the strain (apparent strain) that occurs when the strain gauge manufactured in Example 1 is attached to a non-elastic material of 100°C / °C. In this case, the range in which the strain value of the strain gauge manufactured in Example 1 is close to zero is 10 to 100°C. This range is called the self-temperature compensation range. The strain gauge obtained in this example has a linear expansion coefficient β s Therefore, it can be said that this strain gauge is suitable for materials that are not inherently elastic.

[0032] Commercially available strain gauges have a linear expansion coefficient of 1 to 70 x 10 for the material to be measured. -6 / ℃. In this case, the material to be measured is unknown or has an unknown linear expansion coefficient (β T ) is calculated by dividing the strain difference of the material being measured by the temperature difference at that time, and the strain difference of the commercially available strain gauge by the temperature difference at that time, and then dividing the difference by the linear expansion coefficient β s By adding T ) can be seen. This is expressed by the following formula:

number

[0033] On the other hand, the linear expansion coefficient β s -0.5×10 -6 / ℃~+0.5×10 -6 When using a commercially available strain gauge that is suitable for a material with a linear expansion coefficient of 1 / °C, the formula for calculating the linear expansion coefficient of the material to be measured is complicated, as described above. Therefore, the strain difference of the strain gauge 20 of Example 1 divided by the temperature difference at 10 to 100°C was set to zero, and the linear expansion coefficient β s By setting to zero, the linear expansion coefficient (β T ) can be understood.

number

[0034] In this example, the linear expansion coefficient β s is 0~+0.5×10 -6 A strain gauge suitable for the material with a temperature range of 100 / °C was used on the elastic material to measure the linear expansion coefficient.

[0035] FIG. 4 is a conceptual diagram of the experimental system in Example 2. The strain gauge for non-elastic material obtained in Example 1 was attached to the measurement target material 34 using a dedicated adhesive for strain gauges. A sensor 35 (for example, a thermocouple) capable of measuring the temperature of the measurement target material 34 was attached to the measurement target material 34. The measurement target material 34 to which the product and the sensor 35 capable of measuring temperature were attached were placed in an environmental test chamber 32 capable of controlling temperature. The strain gauge dedicated lead wire 31 extending from the strain gauge 33 was wired to a measuring instrument 30 capable of measuring strain. The sensor 35 capable of measuring temperature was also wired to a measuring instrument capable of measuring temperature. The measurement temperature was set to 10°C, and the strain and temperature were recorded after 60 to 70 minutes. The measurement temperature was set to 100°C, and the strain and temperature were recorded after 60 to 70 minutes. The strain difference recorded at each temperature was divided by the temperature difference. In this manner, the linear expansion coefficient of the measurement target material 34 can be obtained.

[0036] Fig. 5 is a graph instead of a drawing showing the relationship between temperature (horizontal axis) and temperature-induced strain (apparent strain) when an aluminum material is used as the measurement target material in Example 2. Table 1 shows the results of Fig. 5. [Table 1] Using this result, the thermal expansion coefficient of the aluminum material used as the measurement target material 34 is calculated by the following formula.

number

[0037] According to the embodiment, the linear expansion coefficient β s =-0.5~+0.5×10 -6 In implementing a strain gauge suitable for a material having a temperature of 100 °C / °C, the linear expansion coefficient (β T ) can now be calculated.

[0038] The range in which the linear expansion coefficient can be measured by the strain gauge 20 of Example 1 is 0 to 150×10-6 / °C and has a thickness of 1.5 mm or more. The temperature is 10 to 100°C, which is the range where the strain value of the strain gauge is close to zero. The tolerance for the obtained linear expansion coefficient value is ±0.5×10 -6 / ℃. [Industrial Applicability]

[0039] The present invention can be used in the field of measuring instruments. [Explanation of symbols]

[0040] 1 Measuring equipment 3 Sensing part

Claims

1. A measuring device (1) for measuring a linear expansion coefficient having a sensing part (3), The linear expansion coefficient of the sensing part (3) is β ｓ Then, β ｓ is 0 or more and 0.5 x 10 －６ An apparatus for measuring the coefficient of linear expansion (1), which is less than 1 / °C.

2. A method for measuring the linear expansion coefficient of an object to which the linear expansion coefficient measuring device (1) according to claim 1 is attached, comprising the steps of: obtaining a first heat output value, the first heat output value being a heat output value of the object at a first temperature; obtaining a second heat output value, the second heat output value being a heat output value of the object at a second temperature; and determining a coefficient of linear expansion of the object using the first temperature, the first heat output value, the second temperature, and the second heat output value.

3. 3. The method of claim 2, The step of determining the linear expansion coefficient of the object includes: The first temperature, the second temperature, the first heat output value, the second heat output value, and the linear expansion coefficient of the object are respectively defined as T １ , T ２ , ε ａｐｐ１ , ε ａｐｐ２ And, β ｓ When β ｓ = (ε ａｐｐ２ -ε ａｐｐ１ ) / (T ２ -T １ ) to determine the linear expansion coefficient of the object.

4. A system for measuring a linear expansion coefficient comprising an apparatus (1) for measuring a linear expansion coefficient according to claim 1, For an object to which the linear expansion coefficient measuring device 1 is attached, from the linear expansion coefficient measuring device (1), A first heat output value acquisition unit (11) that acquires a first heat output value, which is a heat output value of the object at a first temperature; a second heat output value acquisition unit (13) for acquiring a second heat output value which is a heat output value of the object at a second temperature; and a linear expansion coefficient calculation unit (15) that calculates a linear expansion coefficient of the object using the first temperature, the first heat output value, the second temperature, and the second heat output value.

5. A computer connected to the linear expansion coefficient measuring device (1) according to claim 1, For an object to which the linear expansion coefficient measuring device 1 is attached, from the linear expansion coefficient measuring device (1), obtaining a first heat output value, the first heat output value being a heat output value of the object at a first temperature; obtaining a second heat output value, the second heat output value being a heat output value of the object at a second temperature; and determining a linear expansion coefficient of the object using the first temperature, the first heat output value, the second temperature, and the second heat output value.

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