JP6346390B1 - Normal incident acoustic characteristic measuring apparatus and normal incident acoustic characteristic measuring method - Google Patents

Abstract

Provided are a normal incident acoustic characteristic measuring apparatus and a normal incident acoustic characteristic measuring method capable of effectively measuring normal incident acoustic characteristics at high temperatures. The normal incidence acoustic characteristic measuring apparatus includes a tube body in which a sound source is disposed at one end, a test body to be measured is disposed in a tube, and a sound pressure sensor is disposed between the sound source and the test body, The first tube wall portion including the first position is heated under a condition determined based on a first temperature measured at a first position between the sound source of the tube main body and the specimen. Determined based on a second temperature measured at a second position between the first heating control unit and the sound source of the tube body and the test body and closer to the sound source than the first position. And a second heating control unit that heats the second tube wall portion including the second position.

Description

  The present invention relates to a normal incidence acoustic characteristic measurement apparatus and a normal incidence acoustic characteristic measurement method.

  In Non-Patent Document 1, a transparent quartz tube is used as a standing wave tube, the transparent quartz tube on which the sample is arranged is heated to 400 ° C. in an annular electric furnace, and the sample is subjected to the standing wave ratio method. It is described that the normal incident sound absorption coefficient was measured.

The Acoustical Society of Japan, Vol. 40, No. 9, (1984) 612-619

  However, when measuring normal incidence acoustic characteristics at high temperatures, there are problems with conventional devices and methods.

  The present invention has been made in view of the above problems, and an object thereof is to provide an apparatus and a method capable of effectively measuring normal incident acoustic characteristics at high temperatures.

  In order to solve the above problems, a normal incidence acoustic characteristic measuring apparatus according to an embodiment of the present invention includes a sound source disposed at one end, a test body to be measured disposed in a tube, and the sound source and the test body. A tube body in which a sound pressure sensor is disposed, and a condition determined based on a first temperature measured at a first position between the sound source of the tube body and the test body, A first heating control unit that heats the first tube wall portion including the first position; and a second portion closer to the sound source than the first position between the sound source of the tube main body and the test body. And a second heating control unit that heats the second tube wall portion including the second position under a condition determined based on the second temperature measured at the second position. ADVANTAGE OF THE INVENTION According to this invention, the normal incidence acoustic characteristic measuring apparatus which can measure the normal incidence acoustic characteristic in high temperature effectively is provided.

  In order to solve the above problems, a normal incidence acoustic characteristic measurement method according to an embodiment of the present invention includes a sound source disposed at one end, a test body to be measured disposed in a tube, and the sound source and the test body. A device including a tube body having a sound pressure sensor disposed therebetween, determined based on a first temperature measured at a first position between the sound source of the tube body and the test body And heating the first tube wall portion including the first position under the conditions, and between the sound source of the tube main body and the test body and closer to the sound source than the first position. Heating a second tube wall portion including the second position under conditions determined based on a second temperature measured at a second position; and from the sound source into the heated tube body tube While emitting sound waves toward the test body, the sound pressure in the tube is measured by the sound pressure sensor. Measuring, and based on a measurement result by the sound pressure sensor, comprising, for evaluating the normal incidence sound characteristics of the specimen. According to the present invention, there is provided a normal incidence acoustic characteristic measurement method capable of effectively measuring normal incidence acoustic characteristics at high temperatures.

  In order to solve the above problems, a normal incidence acoustic characteristic measuring apparatus according to an embodiment of the present invention includes a sound source disposed at one end, a test body to be measured disposed in a tube, and the sound source and the test body. And a tube wall portion included between the test body of the tube body and the sound pressure sensor is heated by an opposing heater, Increase in the temperature of the sound source by promoting heat dissipation from the non-heated part not facing the heater and / or increasing the thermal resistance of the non-heated part included in the tube wall between the pressure sensor and the sound source And a temperature rise suppression part that suppresses. ADVANTAGE OF THE INVENTION According to this invention, the normal incidence acoustic characteristic measuring apparatus which can measure the normal incidence acoustic characteristic in high temperature effectively is provided.

  In order to solve the above problems, a normal incidence acoustic characteristic measurement method according to an embodiment of the present invention includes a sound source disposed at one end, a test body to be measured disposed in a tube, and the sound source and the test body. An apparatus including a tube body in which a sound pressure sensor is disposed between the tube body, and a tube wall portion included between the test body of the tube body and the sound pressure sensor is heated by an opposing heater. A sound wave is radiated from the sound source toward the test body in the tube of the heated tube body, and is included in a tube wall between the sound pressure sensor of the heated tube body and the sound source. While the heat pressure from the non-heated part not facing the heater is promoted and / or the thermal resistance of the non-heated part is increased to suppress an increase in the temperature of the sound source, the sound pressure sensor causes the sound in the pipe to Measuring pressure, and said sound pressure sensor Based on the measurement result by including it, to evaluate the normal incidence sound characteristics of the specimen. ADVANTAGE OF THE INVENTION According to this invention, the normal incidence acoustic characteristic measuring apparatus which can measure the normal incidence acoustic characteristic in high temperature effectively is provided.

  In order to solve the above problems, a normal incidence acoustic characteristic measuring apparatus according to an embodiment of the present invention includes a sound source disposed at one end, a test body to be measured disposed in a tube, and the sound source and the test body. A tube main body in which a sound pressure sensor is disposed, and a sound-transmitting heat insulating material disposed in the tube of the tube main body. ADVANTAGE OF THE INVENTION According to this invention, the normal incidence acoustic characteristic measuring apparatus which can measure the normal incidence acoustic characteristic in high temperature effectively is provided.

  In order to solve the above problems, a normal incidence acoustic characteristic measurement method according to an embodiment of the present invention includes a sound source disposed at one end, a test body to be measured disposed in a tube, and the sound source and the test body. A device including a tube main body in which a sound pressure sensor is disposed, and a sound-transmitting heat insulating material disposed in the tube of the tube main body, the test body of the tube main body, and the Heating the tube wall portion included between the sound pressure sensor and the sound pressure while radiating sound waves from the sound source to the test body through the heat insulating material into the heated tube body. Measuring a sound pressure in the tube by a sensor, and evaluating a normal incident acoustic characteristic of the specimen based on a measurement result by the sound pressure sensor. ADVANTAGE OF THE INVENTION According to this invention, the normal incidence acoustic characteristic measuring apparatus which can measure the normal incidence acoustic characteristic in high temperature effectively is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the normal incident acoustic characteristic measuring apparatus and the normal incident acoustic characteristic measuring method which can measure the normal incident acoustic characteristic in high temperature effectively are provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which shows the main structure by a cross sectional view about an example of the normal incidence acoustic characteristic measuring apparatus which concerns on the 1st side surface of one Embodiment of this invention. It is explanatory drawing which shows the result of having performed numerical simulation about the conventional normal incidence acoustic characteristic measuring apparatus. It is explanatory drawing which shows the result of having performed numerical simulation about an example of the normal incidence acoustic characteristic measuring apparatus which concerns on the 1st side surface of one Embodiment of this invention. It is explanatory drawing which shows the main structure by a cross sectional view about an example of the normal incidence acoustic characteristic measuring apparatus which concerns on the 2nd side surface of one Embodiment of this invention. It is explanatory drawing which shows the main structure by sectional view about the other example of the normal incidence acoustic characteristic measuring apparatus which concerns on the 2nd side surface of one Embodiment of this invention. It is explanatory drawing which shows the main structure by a cross sectional view about the further another example of the normal incidence acoustic characteristic measuring apparatus which concerns on the 2nd side surface of one Embodiment of this invention. It is explanatory drawing which shows the main structure by a cross sectional view about the further another example of the normal incidence acoustic characteristic measuring apparatus which concerns on the 2nd side surface of one Embodiment of this invention. It is explanatory drawing which shows the main structure by a cross sectional view about the further another example of the normal incidence acoustic characteristic measuring apparatus which concerns on the 2nd side surface of one Embodiment of this invention. It is explanatory drawing which shows the main structure by a cross-sectional view about an example of the normal incidence acoustic characteristic measuring apparatus which concerns on the 3rd side surface of one Embodiment of this invention. It is explanatory drawing which shows the result of having performed the numerical simulation about an example of the normal incidence acoustic characteristic measuring apparatus which concerns on the 3rd side surface of one Embodiment of this invention.

  Hereinafter, a normal incidence acoustic characteristic measurement apparatus (hereinafter referred to as “this apparatus”) and a normal incidence acoustic characteristic measurement method (hereinafter referred to as “this method”) according to an embodiment of the present invention will be described. The present invention is not limited to the example shown in the present embodiment.

  1 to 10 show the main configuration of the example of the present apparatus in a cross-sectional view. Hereinafter, the apparatus and the method will be described with reference to these drawings.

  First, the basic configuration of the apparatus 1 and the method will be described. In the present apparatus 1, the sound source 20 is disposed at one end 10 a, the test object 30 to be measured is disposed in the tube 10 c, and the sound pressure sensor 40 is disposed between the sound source 20 and the test object 30. It includes the tube body 10 and is used for measuring the normal incident acoustic characteristics of the test body 30.

  Further, in this method, the sound source 20 is disposed at one end 10 a, the test object 30 to be measured is disposed in the tube 10 c, and the sound pressure sensor 40 is disposed between the sound source 20 and the test object 30. This is a method for measuring the normal incident acoustic characteristics of the specimen 30 including preparing an apparatus including the tube body 10 (for example, the present apparatus 1).

  The normal incident acoustic characteristics measured by the apparatus 1 and the method are not particularly limited as long as the acoustic characteristics are measured by vertically incident sound waves on the test body 30. For example, the normal incident acoustic absorption characteristics and / or Or a normal incident sound insulation characteristic is mentioned.

  The normal incident sound absorption characteristic is not particularly limited as long as it is a characteristic related to the sound absorption of the test body 30. For example, the normal incident sound absorption coefficient, specific acoustic impedance, complex sound pressure reflection coefficient, sound pressure reflectivity, transfer function, characteristic impedance, propagation One or more selected from the group consisting of a constant, effective density, and bulk modulus can be mentioned, and the normal incident sound absorption coefficient is particularly preferably measured.

  The normal incident sound insulation characteristic is not particularly limited as long as it is a characteristic relating to the sound insulation of the test body 30, and is selected from the group consisting of normal incident sound transmission loss, transfer function, characteristic impedance, propagation constant, effective density, and bulk modulus, for example. In particular, normal incident sound transmission loss is preferably measured.

  When there is a standard for measurement of normal incidence acoustic characteristics, the apparatus 1 and the method are used by a method based on the standard or a method based on the standard with a modification necessary for measurement at a high temperature. It is preferable to perform the measurement according to.

  Examples of the standards include JIS A1405-2: 2007, ISO 10534-2: 1998 and ASTM E 1050, which specify transfer function methods, and standing wave ratio method, for measuring sound absorption coefficient and impedance by an acoustic tube. JIS A1405-1: 2007 and ISO 10534-1: 1996, and regarding normal incident sound transmission loss, ASTM E2611 is mentioned.

  The tube body 10 is not particularly limited as long as it is a tubular body that can be used for measurement of normal incidence acoustic characteristics. For example, a tubular body (for example, a so-called acoustic tube) having characteristics defined by the above-mentioned standard is preferably used.

  The cross-sectional shape of the tube body 10 is not particularly limited, but is preferably, for example, a circular shape or a square shape. In the example shown in the drawings of this embodiment, a tube body 10 having a circular cross-sectional shape is used.

  One end portion 10a of the tube body 10 is open, and the sound source 20 is disposed so as to close the opening in the measurement by the apparatus 1 and the method. On the other hand, the other end 10b of the tube body 10 is closed. The tube body 10 shown in the drawings of the present embodiment includes a back plate portion 11a that closes the longitudinal direction of the other end portion 10b. The back plate portion 11a is preferably formed so as to function as a rigid end in the measurement of normal incidence acoustic characteristics.

  In the example shown in the drawings of the present embodiment, the test body 30 is disposed so as to be in close contact with the sound source 20 of the back plate portion 11a of the tube main body 10. However, the test body 30 and the back plate portion are provided as necessary. You may form a back air layer (not shown) between 11a.

  For example, when measuring normal incident sound insulation characteristics (for example, normal incident sound transmission loss), the sound pressure of the sound wave transmitted through the test body 30 is measured between the test body 30 and the back plate portion 11a. A space for measurement may be formed. In this case, for example, a position symmetrical to the first sound pressure sensor 41 shown in the drawing of the present embodiment and the second sound are sandwiched between the test body 30 and the back plate portion 11a. The sound pressure is measured at a position symmetrical to the pressure sensor 42. For this reason, this apparatus 1 may arrange | position a sound pressure sensor (not shown) further between the test body 30 and the backplate part 11a. In this case, a sound absorbing material (not shown) may be disposed between the added sound pressure sensor and the back plate portion 11a.

  The tube body 10 may include a test body holding portion 10d for holding the test body 30 in the tube 10c. The test body holding part 10d is not particularly limited as long as it is a member suitable for holding the test body 30, but is specified by the above-mentioned standard (for example, specified by JIS A1405-2: 2007 and JIS A1405-1: 2007). Specimen holder). 10 d of test body holding | maintenances are the tubular bodies which comprise the other end part 10b of the tube main body 10, or comprise the middle part between the one end part 10a and the other end part 10b of the tube main body 10, for example. In the example shown in the drawings of the present embodiment, the other end portion 10b of the tube body 10 includes a test body holding portion 10d that is a tubular member. And the test body holding | maintenance part 10d contains the backplate part 11a which is a rigid end which blocks the longitudinal direction end.

  The sound source 20 is not particularly limited as long as it is a device that can radiate sound waves suitable for measurement of normal incidence acoustic characteristics from the one end 10a of the tube body 10 to the tube interior 10c. For example, a speaker defined by the above standard is preferably used. It is done. In the example shown in the drawings of the present embodiment, a cone-shaped speaker is used as the sound source 20.

  The sound source 20 emits sound waves according to the measurement method. That is, for example, in the measurement by the transfer function method, the sound source 20 radiates broadband noise for forming a plane wave sound field in the tube 10 c between the test body 30 and the sound pressure sensor 40. In the measurement by the standing wave ratio method, the sound source 20 emits a pure sound.

  In the measurement by the apparatus 1 and the method, the sound pressure sensor 40 is disposed between the sound source 20 of the tube main body 10 and the test body 30. The sound pressure sensor 40 is not particularly limited as long as it is a device capable of measuring the sound pressure in the tube 10c. For example, a microphone defined by the above standard is preferably used. A probe microphone may be used as the microphone.

  In the example shown in the drawings of the present embodiment, the first sound pressure sensor 41 disposed on the tube wall 11 between the sound source 20 of the tube body 10 and the test body 30 and the longitudinal direction of the tube body 10 A second sound pressure sensor 42 disposed at a predetermined distance from the first sound pressure sensor 41 toward the sound source 20 is used.

  Specifically, as the illustrated sound pressure sensors 41 and 42, probe microphones including microphone bodies 41a and 42a including diaphragms and probe tubes 41b and 42b connected to the microphone bodies 41a and 42a are used. Yes.

  The number and arrangement of the sound pressure sensors 40 are appropriately set according to the measurement method. That is, in the example shown in the drawings of the present embodiment, two microphones, ie, the first sound pressure sensor 41 and the second sound pressure sensor 42 are used. However, the present invention is not limited to this. For example, one microphone is used. The measurement of the sound pressure at the position of the first sound pressure sensor 41 and the measurement of the sound pressure at the position of the second sound pressure sensor 42 may be performed.

  Further, for example, instead of the microphone disposed on the tube wall 11, a probe microphone (not shown) extending in the longitudinal direction of the tube body 10 from the sound source 20 side toward the test body 30 side is disposed in the tube 10c, By moving the position of the tip of the probe microphone (tip facing the test body 30), the measurement of the sound pressure at the position of the first sound pressure sensor 41 shown in the drawing and the position of the second sound pressure sensor 42 are performed. The sound pressure may be measured.

  In the measurement by the apparatus 1 and the method, the test body 30 is disposed in the tube 10c of the tube body 10. The test body 30 is not particularly limited as long as it can measure the normal incident acoustic characteristics by the apparatus 1 and the method. The shape of the test body 30 is not particularly limited as long as the normal incidence acoustic characteristics can be measured, but the shape defined by the above standard is preferable. That is, for example, the surface 30a on the sound source 20 side of the test body 30 is preferably flat. The test body 30 is disposed so as to close the inside 10 c of the tube in the longitudinal direction of the tube body 10.

  In the measurement by the apparatus 1 and the method, the temperature of the tube 10c (that is, the temperature of the gas (for example, air) filled in the tube 10c) is set to a relatively high desired temperature by heating the tube body 10. The sound wave is emitted from the sound source 20 toward the test body 30 in the heated tube interior 10c, and the sound pressure in the tube 10c is measured by the sound pressure sensor 40.

  For this reason, at the time of measurement, the apparatus 1 includes a heater 50 that heats the tube body 10. The heater 50 is not particularly limited as long as it is a device that can heat the tube main body 10 so that the temperature of the tube 10c is maintained within a desired temperature range. For example, a heater that generates heat when supplied with electric power is preferably used. Specifically, as the heater 50, for example, at least one selected from the group consisting of an electric heater, a lamp heater, an oil bath, a water bath, a sand bath, and a salt bath is used. In the example shown in the drawings of the present embodiment, an electric heater is used as the heater 50.

  The heater 50 is arrange | positioned at the radial direction outer side of the said tube wall 11 so as to oppose the part which should be heated of the tube wall 11 of the tube main body 10, as shown to drawing of this embodiment. The position of the heater 50 is not particularly limited as long as the tube wall 11 can be heated so that the temperature in the tube 10c of the tube main body 10 is within a desired temperature range, and the heater 50 is disposed away from the outer surface 11b of the tube wall 11. It may be arranged so as to be in contact with the outer surface 11b.

  In the measurement by the apparatus 1 and the method, as described above, the tube wall 11 of the tube body 10 is heated so that the temperature of the tube 10c of the tube body 10 is maintained within a relatively high desired temperature range.

  Specifically, for example, the temperature in the tube 10c of the tube body 10 may be heated to 100 ° C. or higher, heated to 200 ° C. or higher, or heated to 300 ° C. or higher. Well, it may be heated to 400 ° C. or higher, heated to 500 ° C. or higher, heated to 600 ° C. or higher, heated to 700 ° C. or higher, You may heat so that it may become 800 degreeC or more. The upper limit value of the heating temperature in the tube 10c is not particularly limited as long as it can be measured by the apparatus 1 and the method, but the heating temperature may be, for example, 1000 ° C. or less.

  In addition, the temperature of the tube wall 11 of the tube body 10 may be heated to, for example, 100 ° C. or higher, may be heated to 200 ° C. or higher, and may be heated to 300 ° C. or higher. , Heated to 400 ° C. or higher, heated to 500 ° C. or higher, heated to 600 ° C. or higher, heated to 700 ° C. or higher, 800 You may heat so that it may become more than degreeC. The upper limit value of the heating temperature of the tube wall 11 is not particularly limited as long as it can be measured by the apparatus 1 and the method, but the heating temperature may be, for example, 1000 ° C. or less.

  In the measurement by the apparatus 1 and the method, the normal incident acoustic characteristics of the test body 30 are evaluated based on the measurement result by the sound pressure sensor 40 under heating. That is, for example, as shown in the drawing of the present embodiment, when measurement is performed by the transfer function method using two sound pressure sensors 41 and 42, based on the measurement results by the two sound pressure sensors 41 and 42. Then, a transfer function between the measurement positions of the two sound pressure sensors 41 and 42 is measured, and a normal incident acoustic characteristic is calculated based on the obtained transfer function.

  For this reason, the present apparatus 1 may include an evaluation processing unit (not shown) that evaluates the normal incident acoustic characteristics of the test body 30 based on the measurement result by the sound pressure sensor 40. The evaluation processing unit is realized by, for example, an arithmetic device including a processor (for example, a computer including a CPU). In other words, the evaluation processing unit of the present apparatus 1 accepts the sound pressure measurement result from the sound pressure sensor 40 and evaluates the sound pressure measurement result, for example, when evaluating the normal incident acoustic characteristics by the transfer function method. To calculate a transfer function, and further, an arithmetic process based on the transfer function is executed to calculate a normal incident acoustic characteristic.

  Next, the apparatus 1 and the method according to the first aspect of the present embodiment will be described mainly with reference to FIGS.

  As shown in FIG. 1, the present apparatus 1 according to the first aspect of the present embodiment has a first temperature measured at a first position X <b> 1 between the sound source 20 of the tube body 10 and the test body 30. Between the first heating control unit 110 that heats the first tube wall portion 101 including the first position X1 and the sound source 20 and the test body 30 of the tube main body 10 under the conditions determined based on the conditions. Under the conditions determined based on the second temperature measured at the second position X2 closer to the sound source 20 than the first position X1, the second tube wall portion 102 including the second position X2 is And a second heating control unit 120 for heating.

  In addition, the method according to the first aspect of the present embodiment includes the first position X1 under a condition determined based on the first temperature measured at the first position X1 of the pipe body 10. The first tube wall portion 101 is heated and the second position X2 including the second position X2 is determined under a condition determined based on the second temperature measured at the second position X2 of the tube body 10. Heating the tube wall portion 102 and measuring the sound pressure in the tube 10c by the sound pressure sensor 40 while radiating sound waves from the sound source 20 toward the test body 30 to the tube 10c of the heated tube body 10 And evaluating the normal incident acoustic characteristics of the test body 30 based on the measurement result by the sound pressure sensor 40.

  Here, in Non-Patent Document 1 described above, the tip of the microphone probe extending in the longitudinal direction of the standing wave tube is required to be in a temperature uniform region, and the standing wave heated by the annular electric furnace is used. Of the tubes, it was determined that the uniform temperature should be within the range from the sample (arranged in the center of the electric furnace) to the distance (about 250 mm) corresponding to a quarter of the wavelength in the furnace end direction. When the temperature of the sample is 400 ° C., the temperature is 400 ° C. to 390 ° C. within a range of about 250 mm from the sample, and it is evaluated that the sample is almost uniform.

  However, as a result of independent studies by the inventors of the present invention, the temperature in the tube 10c is made uniform in the longitudinal direction only by performing heating control based on the temperature of the tube wall 11 near the test body 30 of the tube body 10. It turned out to be difficult. If the temperature in the tube 10c is not uniform in the longitudinal direction, it is difficult to form a sound field (for example, a plane wave sound field in the measurement by the transfer function method) suitable for measuring the normal incident acoustic characteristics in the tube 10c. .

  That is, in the result of the numerical simulation shown in FIG. 2, the single wall 50 of the pipe body 10 in the range from the surface 30 a on the sound source (not shown) side of the test body 30 to the sound source side is 400 mm. When heating is performed, that is, when heating control is performed with only one system (when the heater 50 is PID-controlled so that the temperature measured at the position of the test body 30 is 400 ° C.), the test body 30 is concerned. Even when the temperature of the tube wall 11 at the position of 400 mm has reached 400 ° C., the distance from the surface 30a of the test body 30 to the sound source side is 250 mm (a distance corresponding to a quarter of the wavelength in Non-Patent Document 1 above). ) The temperature of the air in the tube 10c at a distant position is 359 ° C, and it was shown that a temperature drop of 41 ° C occurs from the target temperature of 400 ° C.

  In the numerical simulation, the natural convection of the air in the pipe 10c is calculated using the Bucinesque approximation using a computer on which commercially available thermal fluid analysis software (SCRYU / Tetra (registered trademark), manufactured by Software Cradle Co., Ltd.) is installed. The calculation was performed by calculating the temperature distribution of air in the pipe 10c. The physical property values of air were referred to a known document “Technical data: Thermophysical property value collection of fluid, Japan Society of Mechanical Engineers (1983)”. As a physical property value of the acoustic tube, a physical property value mounted on the software SCRYU / Tetra (registered trademark) was used.

  On the other hand, the inventors of the present invention independently studied technical means for equalizing the temperature in the longitudinal direction of the pipe interior 10c. By including a plurality of heating control systems that respectively control heating at the plurality of positions based on the temperatures measured at the plurality of positions, and in the present method, at a plurality of positions on the tube wall 11 of the tube body 10. It has been found that by controlling the heating at the plurality of positions based on the measured temperatures, it is possible to effectively equalize the temperature in the tube 10c of the tube body 10 in the longitudinal direction.

  That is, in the result of the numerical simulation shown in FIG. 3, the tube wall portion 101 of the tube body 10 in the range from the surface 30a on the sound source (not shown) side of the test body 30 to the position of 250 mm on the sound source side is the first. When the tube wall portion 102 in the range from the position of 250 mm to the position of 400 mm toward the sound source is heated by the second heater 52, that is, when heating control is performed in two systems (test The first heater 51 is subjected to PID control so that the temperature measured at the position of the body 30 becomes the target temperature of 400 ° C., and independently from this, it is measured at the position heated by the second heater 52. In the case where the second heater is subjected to PID control so that the temperature becomes the target temperature of 400 ° C.), the surface 30a of the test body 30 is measured with the temperature of the test body 30 reaching 400 ° C. Temperature drop from the temperature of the air in the tube 10c at the sound source side position away 250mm The 381 ° C., and the target temperature was shown to be less than half of the case shown in FIG. In the simulation shown in FIG. 3, a temperature sensor is added at a position heated by the second heater 52, and the temperature measured by the added temperature sensor is set to the target temperature of 400 ° C. The output of the heater 52 was performed under the same conditions as in FIG. 2 except that PID control was performed independently of the output of the first heater 51.

  The method for determining the heating condition based on the measured temperature is not particularly limited as long as the heating can be realized according to the measured temperature. The condition may be determined. Specifically, the heating condition may be determined using, for example, one or more selected from the group consisting of P control, PI control, and PID control.

  That is, in this method, the first pipe is used under the condition determined based on the difference between the first temperature measured at the first position X1 of the pipe body 10 and the predetermined first target temperature. The wall portion 101 is heated, and the second temperature measured at the second position X2 of the tube body 10 and the second target temperature determined based on the difference between the predetermined second target temperature and the second temperature The tube wall portion 102 may be heated.

  In addition, the present apparatus 1 is configured so that the first pipe is subjected to a condition determined based on a difference between the first temperature measured at the first position X1 of the pipe body 10 and a predetermined first target temperature. The first heating control unit 110 that heats the wall portion 101, the condition determined based on the difference between the second temperature measured at the second position X2 and a predetermined second target temperature, It is good also as including the 2nd heating control part 120 which heats the 2nd pipe wall part 102. FIG.

  The first target temperature and the second target temperature are preferably the same temperature, but may be different temperatures. The difference between the first target temperature and the second target temperature may be appropriately determined according to the measurement conditions, but may be, for example, 20 ° C. or less, preferably 10 ° C. or less, It is more preferably 5 ° C. or lower, and particularly preferably 1 ° C. or lower.

  Further, the difference between the first target temperature (° C.) and the second target temperature (° C.) may be 20% or less of the first target temperature, and is preferably 10% or less, It is more preferably 5% or less, and particularly preferably 1% or less.

  The method for determining the first target temperature and the second target temperature is not particularly limited. For example, the first correlation between the temperature of the tube wall 11 at the first position X1 of the tube main body 10 and the temperature of the tube 10c. And the second correlation between the temperature of the tube wall 11 and the temperature of the tube 10c at the second position X2 is confirmed in advance, and the first correlation and the second correlation should be achieved in the measurement. The first target temperature and the second target temperature may be determined based on the target temperature in the pipe 10c.

  The heating condition determined based on the measurement temperature is not particularly limited as long as it is suitable for uniformizing the temperature in the tube 10c of the tube body 10 in the longitudinal direction. For example, the heating intensity, the heating frequency, and the heating One or more selected from the group consisting of periods may be mentioned.

  That is, as heating conditions in the case of using an electric heater, for example, the intensity of heat generated by the electric heater (more specifically, the power supplied to the electric heater), the frequency of turning on / off the electric heater, And one or more selected from the group consisting of periods when periodic heating is performed by the electric heater.

  The first tube wall portion 101 heated by the first heating control unit 110 does not include the second position X2, and the second tube wall portion 102 heated by the second heating control unit 120 is , Does not include the first position X1. That is, the first tube wall portion 101 and the second tube wall portion 102 are different portions of the tube wall 11 of the tube body 10.

  Further, the heating condition of the first tube wall portion 101 is determined based on the first temperature without being based on the second temperature, and the heating condition of the second tube wall portion 102 is based on the first temperature. Instead, it may be determined based on the second temperature.

  The first heating control unit 110 includes a first temperature sensor 111 that measures a first temperature at a first position X1 of the tube body 10, and a first tube wall portion 101 that includes the first position X1. A first heater 51 for heating, and a first control processing unit 112 for controlling heating by the first heater 51 based on the first temperature, and the second heating control unit 120 includes the tube A second temperature sensor 121 that measures a second temperature at a second position X2 of the main body 10, a second heater 52 that heats the second tube wall portion 102 including the second position X2, and A second control processing unit 122 that controls heating by the second heater 52 based on the second temperature may be included.

  That is, in this case, the present apparatus 1 has a temperature sensor that measures the temperature of a part of the pipe wall 11 of the pipe body 10, a heater that heats a part of the pipe wall, and the temperature measured by the temperature sensor. And at least two heating control systems including a control processing unit that controls heating by the heater.

  The first temperature sensor 111 and the second temperature sensor 121 are not particularly limited as long as they can measure the temperature of the tube wall 11 at the first position X1 and the second position X2, respectively. A temperature sensor including an element is preferably used. Examples of the temperature sensitive element include one or more selected from the group consisting of a thermocouple, a resistance temperature detector, a thermistor, and a thermopile (radiation thermometer).

  The positions of the first temperature sensor 111 and the second temperature sensor 121 are within a range in which the substantial temperature of the tube wall 11 can be measured at the first position X1 and the second position X2 of the tube body 10, respectively. For example, it may be arranged away from the outer surface 11b of the tube wall 11 of the tube body 10, or may be arranged so as to be in contact with the outer surface 11b.

  The first heater 51 and the second heater 52 are not particularly limited as long as they are devices that can heat the tube wall 11 of the tube body 10. For example, a heater that generates heat when supplied with electric power is preferably used. Specifically, as the heaters 51 and 52, for example, at least one selected from the group consisting of an electric heater, a lamp heater, an oil bath, a water bath, a sand bath, and a salt bath is used. In the example shown in FIG. 1, electric heaters are used as the first heater 51 and the second heater 52.

  The first tube wall portion 101 facing the first heater 51 includes, for example, a position where the test body 30 is disposed (for example, a position X3 of the surface 30a of the test body 30 on the sound source 20 side). For example, as shown in FIG. 1, the second tube wall portion 102 opposed to the second heater 52 is a tube wall portion connected to the sound source 20 side of the first tube wall portion 101 in the longitudinal direction of the tube main body 10. It is.

  The control processing units 112 and 122 are not particularly limited as long as they perform arithmetic processing for controlling heating by the heaters 51 and 52 based on the temperature measurement results by the temperature sensors 111 and 121, but include, for example, a processor. It is realized by a control device.

  That is, the control processing units 112 and 121 may be realized by a temperature regulator or a power regulator, for example. In this case, for example, the control processing units 112 and 121 perform arithmetic processing for PID control based on temperature measurement results from the temperature sensors 111 and 121, and supply electric power to be supplied to the heaters 51 and 52 that are electric heaters. A temperature adjusting unit (not shown) for determination and a power adjusting unit (not shown) for supplying electric power instructed from the temperature adjuster to the heaters 51 and 52 are realized.

  The first heating control unit 110 heats the first temperature sensor 111 that measures the first temperature at the first position X1 and the first tube wall portion 101 that includes the first position X1. Heater 51 and a first control processing unit 112 that determines a first heating condition based on a first difference between the first temperature and a predetermined first target temperature. The heating control unit 120 includes a second temperature sensor 121 that measures the second temperature at the second position X2, and a second heater 52 that heats the second tube wall portion 102 including the second position X2. And a second control processing unit 122 that determines a second heating condition based on a second difference between the second temperature and a predetermined second target temperature, and the first heater 51 Heats the first tube wall portion 101 under the first heating condition, and the second heater 52 , It is also possible to heat the second wall portion 102 in the second heating condition.

  That is, for example, when the first heater 51 and the second heater 52 are heaters that generate heat upon receiving power supply, the first control processing unit 112 determines the first heater 51 based on the first difference. The first heating condition relating to the power supply to the first heater 51 is determined, the first heater 51 is heated under the first heating condition to heat the first tube wall portion 101, and the second control The processing unit 122 determines a second heating condition related to power supply to the second heater 52 based on the second difference, and supplies power to the second heater 51 under the second heating condition. Then, the second tube wall portion 102 is heated.

  The first heating control unit 110 and the second heating control unit 120 (more specifically, the first control processing unit 112 and the second control processing unit 122) may determine different heating conditions. it can. That is, for example, when the second difference is larger than the first difference, the second heating condition supplies larger power and / or more frequently than the first heating condition. Decided to do.

  In the apparatus 1 and the method, the first position X1 is between the position X3 of the surface 30a on the sound source 20 side of the test body 30 and the sound pressure measurement position X4 closest to the sound source 20 of the sound pressure sensor 40. The second position X2 may be a position between the sound pressure measurement position X4 and the sound source 20.

  In this case, in addition to the range between the test body 30 and the sound pressure sensor 40, the range between the sound pressure sensor 40 and the sound source 20 is also subjected to heating control based on the measured temperature, whereby the tube body 10. The temperature in the pipe 10c can be made more uniform in the longitudinal direction.

  The sound pressure measurement position X4 closest to the sound source 20 of the sound pressure sensor 40 is the position of the end surface of the sound pressure sensor 40 on the sound source 20 side. In the case of using a plurality of sound pressure sensors (two sound pressure sensors 41 and 42 in the example shown in the drawings of the present embodiment) arranged in the longitudinal direction of the tube body 10, among the plurality of sound pressure sensors, This is the position of the end face on the sound source 20 side of the sound pressure sensor (second sound pressure sensor 42 shown in the drawing of this embodiment) arranged at the position closest to the sound source 20.

  When the sound pressure measurement position X4 is to measure sound pressure at a plurality of positions in the longitudinal direction of the tube body 10 using a single sound pressure sensor, the sound pressure measurement position X4 is the closest to the sound source 20 among the plurality of measurement positions. This is the position of the end face of the sound pressure sensor on the sound source 20 side in a state where the sound pressure sensor is arranged at a close measurement position.

  The sound pressure measurement position X4 uses a probe microphone (not shown) extending in the longitudinal direction of the tube body 10 from the sound source 20 side to the test body 30 side as the sound pressure sensor 40, and a plurality of the sound pressure measurement positions X4 in the longitudinal direction are used. When the sound pressure is measured at the position, the position of the tip surface of the probe microphone (measurement surface facing the test body 30) arranged at the measurement position closest to the sound source 20 among the plurality of measurement positions. It is.

  In the device 1 and the method, the distance L1 between the second position X2 and the sound pressure measurement position X4 may be 25 mm or more. In this case, the distance L1 is preferably 50 mm or more, more preferably 100 mm or more, and particularly preferably 150 mm or more.

  The upper limit value of the distance L1 is not particularly limited as long as the second position X2 is within the range between the sound pressure measurement position X4 and the sound source 20, but the distance L1 is, for example, 500 mm. It may be the following. In this case, the distance L1 may be 400 mm or less, or 300 mm or less.

  The distance L1 can be specified by arbitrarily combining one of the lower limit values and one of the upper limit values. That is, the distance L1 may be, for example, 25 mm or more and 500 mm or less, preferably 50 mm or more and 500 mm or less, and particularly preferably 150 mm or more and 500 mm or less. In these cases, the distance L1 may be 400 mm or less, or 300 mm or less.

  When the distance L1 between the second position X2 and the sound pressure measurement position X4 is within the above-described range, the heating of the tube wall portion on the sound source 20 side from the sound pressure measurement position X4 is more effectively controlled. It is possible to make the temperature in the tube 10c uniform in the longitudinal direction more effectively.

  The method for manufacturing the apparatus 1 according to the first aspect of the present embodiment is not particularly limited. For example, the apparatus 1 first prepares the tube body 10 and then the first heating control unit. 110 and the second heating control unit 120 are manufactured by a method including the above.

  Next, the apparatus 1 and the method according to the second aspect of the present embodiment will be described mainly with reference to FIGS.

  In the present apparatus 1 according to the second aspect of the present embodiment, when the tube wall portion 201 included between the test body 30 of the tube main body 10 and the sound pressure sensor 40 is heated by the opposing heater 50, The heat source is promoted to dissipate heat from the non-heated portion 202 that is included between the sound pressure sensor 40 and the sound source 20 and does not face the heater 50 and / or the thermal resistance of the non-heated portion 202 is increased. 20 includes a temperature increase suppression unit 200 that suppresses a temperature increase of 20.

  Further, the present method according to the second aspect of the present embodiment includes heating the tube wall portion 201 included between the test body 30 of the tube main body 10 and the sound pressure sensor 40 with an opposing heater 50, heating. A sound wave is radiated from the sound source 20 toward the test body 30 into the tube 10c of the tube body 10 and is included between the sound pressure sensor 40 and the sound source 20 of the heated tube body 10. The sound pressure sensor 40 is configured to promote heat dissipation from the non-heated portion 202 that does not face the heater 50 and / or increase the thermal resistance of the non-heated portion 202 to suppress the temperature rise of the sound source 20. To measure the sound pressure in the tube 10 c and to evaluate the normal incident acoustic characteristics of the test body 30 based on the measurement result by the sound pressure sensor 40.

  Here, in Non-Patent Document 1 described above, in heating the standing wave tube, it is described that a transparent quartz tube is used as the standing wave tube, "I dislike heat conduction to the sound source unit". ing.

  However, a method using a special tube such as a transparent quartz tube lacks versatility. On the other hand, conventionally, when a normal acoustic tube is used as it is, the sound source arranged at one end of the acoustic tube may be excessively heated.

  On the other hand, the inventors of the present invention independently studied the technical means for avoiding excessive heating of the sound source, and as a result, the present apparatus 1 is capable of generating sound in the tube wall 11 of the tube body 10. A heat source that promotes heat dissipation from the non-heated portion 202 that is included in the tube wall between the pressure sensor 40 and the sound source 20 and that is not directly heated by the heater 50 and / or increases the thermal resistance of the non-heated portion 202, In addition, in the present method, heat dissipation from the non-heated portion 202 is promoted and / or the thermal resistance of the non-heated portion 202 is increased. It was found that excessive heating of the sound source can be effectively avoided by measuring the sound pressure in the tube 10c with the sound pressure sensor 40 while suppressing the temperature rise of the sound source 20.

  The technical means for promoting the heat radiation from the non-heated portion 202 of the tube body 10 is not particularly limited. For example, the temperature rise suppression unit 200 of the apparatus 1 uses the heat radiation fins 210 provided in the non-heated portion 202. It may be included. In this case, the heat radiation fins can promote heat radiation from the non-heated portion 202 and effectively suppress the temperature rise of the sound source 20.

  The heat dissipating fins 210 provided in the non-heated portion 202 are compared to the outer surface 201a of the tube wall portion 201 (hereinafter referred to as “heated portion”) 201 that is directly heated by the heater 50 disposed opposite thereto, and / or Or as long as it has a structure that promotes heat dissipation from the non-heated portion 202 by increasing the area of the outer surface of the non-heated portion 202 as compared to the case where the outer surface of the non-heated portion 202 is flat. It is not restricted, For example, the convex part 210a which protrudes in the radial direction outer side of the pipe | tube main body 10, and / or the recessed part 210b dented in radial direction inner side are included.

  That is, in the example shown in FIG. 4, the radiating fin 210 of the apparatus 1 includes a plurality of convex portions 210 a provided so as to protrude radially outward of the tube body 10 in the non-heated portion 202 of the tube body 10. It is out. Moreover, in the radiation fin 210 shown in FIG. 4, the some recessed part 210b is formed between the some convex parts 210a. Due to these convex portions 210a and concave portions 210b, the area of the surface 210c of the radiating fin 210 is increased.

  In the tube main body 10, the area of the surface 210 c of the radiating fin 210 (for example, the sum of the area of the convex portion 210 a and the area of the concave portion 210 b) is, for example, the area of the outer surface 201 a of the heating portion 201 facing the heater 50. It is good also as 0.5 times or more of these, It is preferable that it is 0.75 times or more, and it is especially preferable that it is 1.0 times or more. Moreover, the area of the surface 210c of the radiation fin 210 per unit length in the longitudinal direction is, for example, the area of the non-heated portion 202 when the radiation fin 210 is not provided (for example, the non-heating where the radiation fin 210 is provided). 1.2 times or more of the flat outer surface area of the non-heated portion 202 obtained by removing the heat dissipating fins 210 from the portion 202, may be twice or more, and may be five times or more. It is preferably 10 times or more, more preferably 50 times or more, and particularly preferably 100 times or more.

  The tube body 10 may include the heat radiation fins 210 as a part of the tube wall 11. In this case, the radiating fin 210 is formed by molding a tube wall portion that is at least a part of the non-heated portion 202 of the tube body 10. That is, in this case, the present apparatus 1 includes the radiation fins 210 integrally formed on the non-heated portion 202 of the tube wall 11 of the tube body 10.

  In addition, the present apparatus 1 may include a radiating fin 210 that is separate from the tube body 10 and is disposed so as to cover the outer periphery of the non-heated portion 202 of the tube body 10. That is, in this case, the radiating fins 210 are manufactured separately from the tube body 10, and then disposed on the outer periphery of the non-heated portion 202 of the tube body 10 so as to be able to conduct heat.

  The temperature increase suppression unit 200 of the present apparatus 1 may include a thin portion 220 that is included in the non-heated portion 202 and has a smaller thickness than the tube wall portion that is continuous to the specimen 30 side. In this case, the thin-walled portion 220 can increase the thermal resistance of the non-heated portion 202 and effectively suppress the temperature rise of the sound source 20.

  That is, the non-heated portion 202 includes a thin portion 220 and a tube wall portion (hereinafter referred to as a “thick portion”) 230 that is continuous with the thin portion 220 and is thicker than the thin portion 220. By including, the heat resistance in the case where heat is conducted from the thick portion 230 to the thin portion 220 increases.

  More specifically, the tube wall cross-sectional area of the thin-walled portion 220 (the area of the tube wall cross-section exposed by cutting the thin-walled portion 220 in the radial direction) is smaller than the tube wall cross-sectional area of the thick-walled portion 230. When heat is conducted from the meat portion 230 toward the thin portion 220, the thermal resistance increases at the connection portion between the thick portion 230 and the thin portion 220.

  The ratio of the thickness of the thin portion 220 to the thickness of the thick portion 230 may be, for example, 50% or less, preferably 40% or less, more preferably 30% or less, and 20% or less. It is particularly preferred that

  In measuring the normal incident acoustic characteristics, the inner surface (surface on the tube 10c side) 220a of the thin portion 220 is formed at the same position as the inner surface 230a of the thick portion 230 in the radial direction of the tube body 10. It is preferable that That is, as shown in FIG. 5, it is preferable that the inner surface 220a of the thin portion 220 and the inner surface 230a of the thick portion 230 are formed flush with each other.

  On the other hand, the outer surface 220 b of the thin portion 220 may be formed so as to be positioned on the radially inner side of the tube body 10 with respect to the outer surface 230 b of the thick portion 230. That is, the outer diameter of the thin portion 220 may be smaller than the outer diameter of the thick portion 230.

  Specifically, in the example shown in FIG. 5, the outer diameter of the thin portion 220 is smaller than the outer diameter of the thick portion 230, and a step is formed at the connection portion between the thin portion 220 and the thick portion 230. Yes.

  The thick portion 230 is not particularly limited as long as it is a part or the whole of the tube wall 11 connected to the test body 30 side of the thin portion 220. That is, as shown in FIG. 5, the thick portion 230 may be a part of the non-heated portion 202, but is not limited thereto, and may be a part of the heated portion 201.

  The temperature increase suppression unit 200 of the present apparatus 1 may include a cooling unit 240 that circulates a fluid having a temperature lower than the temperature of the non-heated portion 202 around the non-heated portion 202 of the tube body 10. In this case, a fluid having a temperature lower than the temperature of the non-heated portion 202 is circulated around the non-heated portion 202, and heat exchange is performed between the non-heated portion 202 and the fluid, whereby the non-heated portion is heated. The heat dissipation from the part 202 can be promoted, and the temperature rise of the sound source 20 can be effectively suppressed.

  The fluid is not particularly limited as long as it can be circulated around the non-heated portion 202 at a temperature lower than the temperature of the non-heated portion 202 of the tube body 10, and either liquid or gas can be used.

  That is, for example, when water is used as the fluid, the cooling unit 240 is realized as a water-cooled cooling device, and when air is used as the fluid, the cooling unit 240 is realized as an air-cooled cooling device.

  Specifically, for example, the apparatus 1 shown in FIG. 6 is disposed so as to surround the non-heated portion 202 of the tube body 10, and a flow path 241 in which a fluid having a temperature lower than the temperature of the non-heated portion 202 circulates. The cooling part 240 in which is formed is included. The cooling unit 240 cools the non-heated portion 202 by exchanging heat between the fluid flowing in the flow path 241 and the non-heated portion 202.

  The temperature of the fluid is not particularly limited as long as it is lower than the temperature of the non-heated portion 202, but may be lower than the temperature of the non-heated portion 202 by, for example, 1 ° C. or higher, or 5 ° C. or higher. The temperature may be lower by more than ° C.

  The cooling unit 240 is not limited to the example illustrated in FIG. 6, and may be a cooling unit that blows gas to the non-heated portion 202 of the tube body 10, for example. In this case, the cooling unit 240 is a blower that includes, for example, a fan that generates wind by rotating, and cools the non-heated portion 202 by an air cooling method.

  The temperature increase suppression unit 200 of the apparatus 1 may include a cooling unit 250 including a thermoelectric conversion element 251 that is disposed in the non-heated portion 220 of the tube body 10. In this case, the cooling unit 250 can promote heat dissipation from the non-heated portion 202 and effectively suppress an increase in the temperature of the sound source 20.

  Specifically, for example, the apparatus 1 shown in FIG. 7 includes a cooling unit 250 that is disposed so as to surround the non-heated portion 202 of the tube body 10 and includes a thermoelectric conversion element 251 therein.

  The thermoelectric conversion element included in the cooling unit 250 is not particularly limited as long as it can promote heat dissipation from the non-heated portion 202 of the tube main body 10, but is preferably a Peltier element, for example.

  This apparatus 1 includes two or more selected from the group consisting of the above-described heat radiation fins 210, thin-walled portions 220, a cooling unit 240 that circulates fluid, and a cooling unit 250 that includes a thermoelectric conversion element 251 as the temperature rise suppression unit 200. It may be included.

  That is, for example, as shown in FIG. 8, the apparatus 1 includes a thin portion 220 that is continuous with the sound source 20 side of the thick portion 230, and a radiation fin 210 that is provided on the sound source 20 side of the thin portion 220. It is good as well.

  In this case, since the heat resistance from the thick part 230 to the thin part 220 increases and heat radiation is promoted by the radiation fins 210, excessive heating of the sound source 20 can be avoided more effectively.

  In addition, the apparatus 1 includes, for example, a cooling unit 240 and / or a thermoelectric conversion element 251 that are arranged on the outer periphery of the non-heated portion 202 of the tube main body 10 including the radiation fins 210 and / or the thin-walled portions 220. It is good also as including the cooling part 250 containing.

  In addition, although the method in particular of manufacturing this apparatus 1 which concerns on the 2nd side surface of this embodiment is not restricted, For example, this apparatus 1 prepares the pipe | tube main body 10 first, Then, the temperature increase suppression part 200 is set. It is manufactured by a method including providing.

  Next, the apparatus 1 and the method according to the third aspect of the present embodiment will be described mainly with reference to FIGS. 9 and 10.

  As shown in FIG. 9, the device 1 according to the third aspect of the present embodiment includes a sound-transmitting heat insulating material 300 arranged in the tube 10 c of the tube body 10.

  In addition, the method according to the third aspect of the present embodiment prepares an apparatus including the tube main body 10 and a sound-transmitting heat insulating material 300 disposed in the tube inside 10c of the tube main body 10, The tube wall portion 203 included between the test body 30 of the tube body 10 and the sound pressure sensor 40 is heated, and the test is performed from the sound source 20 to the inside 10 c of the heated tube body 10 through the heat insulating material 300. The sound pressure sensor 40 measures the sound pressure in the tube 10 c while emitting sound waves toward the body 30, and based on the measurement result of the sound pressure sensor 40, the normal incident acoustic characteristics of the test body 30. Evaluating.

  Here, in Non-Patent Document 1 described above, a transparent quartz tube as a standing wave tube is heated by an annular electric furnace. However, as a result of independent investigations by the inventors of the present invention, the convection in the tube 10c of the tube body 10, particularly the convection in the longitudinal direction of the tube body 10 makes the temperature in the tube 10c uniform in the longitudinal direction. It turned out to be a big obstacle.

  That is, in the result of the numerical simulation shown in FIG. 2 described above, the test is performed using the heater 50 arranged in a range from the surface 30a on the sound source (not shown) side of the test body 30 to 400 mm on the sound source side. Even if the tube wall 11 of the tube main body 10 is heated so that the temperature of the body 30 reaches 400 ° C., for example, the inside of the range between the range up to 400 mm and the range closer to the sound source where the heater 50 is not disposed. Due to the temperature difference of 10c, natural convection occurs in the tube 10c, so that the temperature of the air in the tube 10c at a position 250 mm away from the surface 30a of the test body 30 toward the sound source is 359 ° C., which is the target temperature. It has been shown that a temperature drop of 41 ° C. occurs from 400 ° C.

  On the other hand, the inventors of the present invention independently studied technical means for equalizing the temperature in the longitudinal direction of the tube interior 10c, and as a result, the apparatus 1 is disposed in the tube body 10c of the tube body 10. In the present method, the sound source 20 is heated in the heated tube interior 10c in a state where the tube body 10 in which the heat insulation material 300 is disposed is heated in the tube 10c. The sound pressure in the tube 10c is measured by the sound pressure sensor 40 while radiating sound waves toward the test body 30 through the heat insulating material 300, thereby effectively convection in the tube 10c of the tube main body 10. It was found that the temperature in the tube 10c can be effectively made uniform in the longitudinal direction.

That is, in the result of the numerical simulation shown in FIG. 10, in the tube main body 10, the heat insulating material 300 having a thickness of 25 mm that partitions the tube 10 c between the test body 30 and the sound source (not shown) is arranged. Convection in the tube 10c is suppressed, and as a result, the temperature of the air in the tube 10c at a position 250 mm away from the surface 30a of the test body 30 to the sound source side in a state where the temperature of the test body 30 reaches 400 ° C. It was 391 ° C., and the temperature drop from the target temperature was 9 ° C., indicating that it was less than a quarter of the case shown in FIG. Incidentally, the simulation shown in FIG. 10, the thickness 25 mm, except that disposed in a state of being in thermal contact with the inner surface of the insulation 300 of the thermal resistance 0.625m ² · K / W tube wall 11, and FIG. 2 The same conditions were used.

  The heat insulating material 300 is not particularly limited as long as it is a material having sound wave permeability that transmits sound waves necessary for measurement from the sound source 20 side to the test body 30 side and heat insulating properties at the measurement temperature.

  The sound wave transmission property of the heat insulating material 300 is defined by, for example, sound transmission loss. The sound transmission loss of the heat insulating material 300 may be, for example, 75 dB or less, 25 dB or less, or 13 dB or less. Furthermore, the sound transmission loss of the heat insulating material 300 is, for example, preferably 8 dB or less, more preferably 2.5 dB or less, still more preferably 0.5 dB or less, and 0.06 dB or less. It is particularly preferred. The sound transmission loss of the heat insulating material 300 is measured by a normal incident sound transmission loss measurement according to ASTM E2611.

The heat insulating property of the heat insulating material 300 is defined by, for example, thermal resistance. The thermal resistance of the heat insulating material 300 may be, for example, as it is 0.00025m ² · K / W or more, preferably 0.125m ² · K / W or more, 0.375m ² · K / W or more It is more preferable that it is 0.625 m ² · K / W or more. The thermal resistance of the heat insulating material 300 is measured by a protective hot plate method in accordance with JIS A 1412-1 or a heat flow meter method in accordance with JIS A 1412-2, and is preferably measured by a protective hot plate method.

  The material which comprises the heat insulating material 300 is not specifically limited, The said heat insulating material 300 is comprised from the material containing 1 or more selected from the group which consists of an organic component, an inorganic component, a metal component, and a carbon component, for example.

  The heat insulating material 300 may be a porous body. The porous body is not particularly limited as long as it is a porous material, and may be, for example, one or more selected from the group consisting of a fibrous body, a foamed body, and a compacted body.

  The fibrous body includes, for example, one or more selected from the group consisting of organic fibers, inorganic fibers, metal fibers, and carbon fibers. Specifically, as the fibrous body, for example, an inorganic fibrous body (for example, one or more selected from the group consisting of glass wool, rock wool, ceramic fiber, and carbon fiber) is preferably used. As the foam, for example, a resin foam (for example, polyurethane foam) is preferably used. As the compact, for example, one or more selected from the group consisting of silicon oxide, aluminum oxide, silicon carbide, and silicon nitride is preferably used.

The porosity of the heat insulating material 300 may be, for example, 0.2 or more and 0.999 or less. The porosity is measured by a suspension method, a liquid immersion method, a mercury intrusion method, or a water evaporation method. The porosity is calculated by the following formula: porosity = 1− (apparent density ÷ density). Here, the apparent density is measured by a density measuring method based on JIS A 9512. Density is a density and specific gravity measurement method using a specific gravity bottle according to JIS Z 8807, a density and specific gravity measurement method using a Le Chatelier specific gravity bottle, a density and specific gravity measurement method using a submerged weighing method, and a density and specific gravity measurement method. Preferably, the density and specific gravity are measured by a specific gravity bottle. The flow resistance per unit thickness of the heat insulating material 300 may be, for example, 10 ³ N · s / m ⁴ or more and 10 ⁸ N · s / m ⁴ or less. The flow resistance is measured by a direct current method according to ISO 9053: 1991.

  The shape of the heat insulating material 300 is not particularly limited as long as the normal incidence acoustic characteristics can be measured, but for example, a plate shape or a sheet shape is preferable.

  The thickness of the heat insulating material 300 (that is, the length in the longitudinal direction of the tube main body 10 or the distance between the surface 300a on the sound source 20 side and the surface 300b on the test body 30 side) is within a range in which the normal incident acoustic characteristics can be measured. Although not particularly limited, for example, it may be 0.01 mm or more and 75 mm or less, preferably 1 mm or more and 25 mm or less, and particularly preferably 1 mm or more and 10 mm or less.

  The heat insulating material 300 is disposed so as to close the inside 10 c of the tube in the longitudinal direction of the tube body 10. That is, in the example shown in FIG. 9, the heat insulating material 300 is arranged between the sound source 20 and the test body 30 so as to partition the tube 10 c. Further, in the example shown in FIG. 9, only one heat insulating material 300 is arranged in the pipe 10 c, but the present invention is not limited to this, and a plurality of heat insulating materials 300 may be arranged.

  The position where the heat insulating material 300 is disposed is not particularly limited as long as the convection in the tube 10c is suppressed, but the heat insulating material 300 is disposed, for example, in the tube 10c between the sound source 20 and the test body 30. In particular, it is preferably disposed in the pipe 10c between the sound source 20 and the sound pressure measurement position X4 closest to the sound source 20 of the sound pressure sensor 40. In this case, convection in the pipe 10c can be effectively suppressed. When a plurality of heat insulating materials 300 are arranged in the longitudinal direction of the pipe 10c, at least one of the plurality of heat insulating materials 300 measures the sound pressure closest to the sound source 20 of the sound source 20 and the sound pressure sensor 40. What is necessary is just to arrange | position in the pipe | tube 10c between the positions X4.

  The apparatus 1 includes a heater 50 that heats the tube wall portion 203 including the sound pressure measurement position X4 of the tube body 10, and at least a part of the heat insulating material 300 is a heating position closest to the sound source 20 of the heater 50. It is good also as arrange | positioning between X5 and the test body 30. FIG.

  Specifically, in the example shown in FIG. 9, the entire heat insulating material 300 is disposed between the heating position X5 closest to the sound source 20 of the heater 50 and the test body 30 in the longitudinal direction of the tube body 10. . In other words, in this case, the heat insulating material 300 is arranged such that the surface 300a on the sound source 20 side is positioned closer to the test body 30 than the heating position X5.

  However, the arrangement of the heat insulating material 300 is not limited to the example shown in FIG. That is, for example, the heat insulating material 300 may be arranged such that the surface 300b on the side of the test body 30 is positioned closer to the test body 30 than the heating position X5.

  Further, when arranging a plurality of heat insulating materials 300 in the longitudinal direction of the tube main body 10, at least a part of the heat insulating material 300 arranged at a position closest to the test body 30 among the plurality of heat insulating materials 300, What is necessary is just to arrange | position between the said heating position X5 and the test body 30. FIG.

  The heating position X5 is the position of the end face closest to the sound source 20 of the heater 50 arranged to face the outer surface 11b of the tube wall 11 of the tube body 10.

  At least a part of the heat insulating material 300 may be disposed between the sound pressure measurement position X4 and the heating position X5. Specifically, in the example shown in FIG. 9, the entire heat insulating material 300 is disposed between the sound pressure measurement position X4 and the heating position X5.

  However, the arrangement of the heat insulating material 300 is not limited to the example shown in FIG. That is, the heat insulating material 300 is disposed such that, for example, the surface 300a on the sound source 20 side and / or the surface 300b on the test body 30 side are located between the sound pressure measurement position X4 and the heating position X5. Is done.

  The method for manufacturing the device 1 according to the third aspect of the present embodiment is not particularly limited. First, the tube body 10 is prepared, and then the sound wave-transmissive heat insulation is provided in the tube 10c of the tube body 10. Manufactured by a method that includes placing material 300.

  The apparatus 1 and the method include two or more selected from the group consisting of the technical feature according to the first aspect, the technical feature according to the second aspect, and the technical feature according to the third aspect. It may include technical features.

  That is, the present apparatus 1 may include, for example, the tube main body 10, the first heating control unit 110, the second heating control unit 120, and the temperature rise suppression unit 200. In addition, the method includes, for example, preparing an apparatus including the tube body 10 and the first tube under conditions determined based on the first temperature measured at the first position X1 of the tube body 10. Heating the wall portion 101, heating the second tube wall portion 102 under conditions determined based on the second temperature measured at the second position X2 of the tube body 10, The tube wall portion 201 included between the test body 30 and the sound pressure sensor 40 is heated from the sound source 20 to the test body 30 in the tube 10 c of the tube body 10 heated by the heater 50 facing the tube wall portion 201. Radiates sound waves toward the heat source, promotes heat radiation from the tube wall portion 202 that is included between the sound pressure sensor 40 of the heated tube body 10 and the sound source 20 and does not face the heater 50, and / Or facing the heater 50 The sound pressure in the tube 10c is measured by the sound pressure sensor 40 while the thermal resistance of the non-tube wall portion 202 is increased to suppress the temperature rise of the sound source 20, and the measurement by the sound pressure sensor 40 Evaluation of the normal incident acoustic characteristics of the test body 30 based on the result may be included.

  The apparatus 1 may include, for example, the tube main body 10, the first heating control unit 110, the second heating control unit 120, and the sound wave transmissive heat insulating material 300. Moreover, this method prepares the apparatus containing the pipe | tube main body 10 and the sound-wave-permeable heat insulating material 300, for example, the 1st temperature measured in said 1st position X1 of the said pipe | tube main body 10 is used. Heating the first tube wall portion 101 under the condition determined based on the second tube under the condition determined based on the second temperature measured at the second position X2 of the tube body 10. Heating the wall portion 102, measuring the sound pressure in the tube 10 c with the sound pressure sensor 40 while radiating sound waves from the sound source 20 toward the test body 30 into the tube 10 c of the heated tube body 10; And evaluating the normal incident acoustic characteristics of the test body 30 based on the measurement result by the sound pressure sensor 40.

  The device 1 may include, for example, the tube main body 10, the temperature rise suppression unit 200, and the sound wave transmissive heat insulating material 300. Moreover, this method prepares the apparatus containing the pipe main body 10 and the sound-wave-permeable heat insulating material 300, for example, the pipe contained between the test body 30 of the said pipe main body 10, and the sound pressure sensor 40. The wall portion 201 is heated by the opposing heater 50, sound waves are emitted from the sound source 20 toward the test body 30 into the heated tube 10 c of the tube body 10, and the heated tube body 10 is heated. The heat radiation from the tube wall portion 202 that does not face the heater 50 and is included between the sound pressure sensor 40 and the sound source 20 is promoted and / or the thermal resistance of the tube wall portion 202 that does not face the heater 50 is increased. Then, while suppressing an increase in the temperature of the sound source 20, the sound pressure sensor 40 measures the sound pressure in the tube 10c, and the test body 30 is based on the measurement result of the sound pressure sensor 40. Evaluating the normal incidence sound characteristics, it may contain.

The apparatus 1 includes, for example, a tube body 10, a first heating control unit 110, a second heating control unit 120, a temperature rise suppression unit 200, and a sound wave transmissive heat insulating material 300. Also good. Moreover, this method prepares the apparatus containing the pipe | tube main body 10 and the sound-wave-permeable heat insulating material 300, for example, the 1st temperature measured in said 1st position X1 of the said pipe | tube main body 10 is used. Heating the first tube wall portion 101 under the condition determined based on the second tube under the condition determined based on the second temperature measured at the second position X2 of the tube body 10. By heating the wall portion 102, the tube wall portion 201 included between the test body 30 of the tube body 10 and the sound pressure sensor 40 is heated by the heater 50 facing the tube wall portion 201. A tube that radiates a sound wave from the sound source 20 toward the test body 30 into the tube 10c and is included between the sound pressure sensor 40 of the heated tube body 10 and the sound source 20, and does not face the heater 50. To promote heat dissipation from the wall 202 And / or measuring the sound pressure in the tube 10c with the sound pressure sensor 40 while increasing the thermal resistance of the tube wall portion 202 not facing the heater 50 and suppressing the temperature rise of the sound source 20. And evaluating the normal incident acoustic characteristics of the test body 30 based on the measurement result by the sound pressure sensor 40.

Claims (13)

A sound source is disposed at one end, a test body to be measured is disposed in the tube, and a tube body in which a sound pressure sensor is disposed between the sound source and the test body,
The first tube wall portion including the first position is heated under a condition determined based on a first temperature measured at a first position between the sound source of the tube main body and the specimen. A first heating control unit;
In a condition determined based on a second temperature measured at a second position between the sound source of the tube main body and the test body and closer to the sound source than the first position, the second A second heating control unit for heating the second tube wall part including the position;
A normal incidence acoustic characteristic measuring apparatus including: The first position is a position between the position of the surface of the test body on the sound source side and the sound pressure measurement position closest to the sound source of the sound pressure sensor,
The second position is a position between the sound pressure measurement position and the sound source.
The apparatus of claim 1. The distance between the second position and the sound pressure measurement position is 25 mm or more.
The apparatus of claim 2. The distance between the second position and the sound pressure measurement position is 500 mm or less.
The apparatus according to claim 2 or 3. The first heating control unit includes a first temperature sensor that measures the first temperature, a first heater that heats the first tube wall portion, and the first temperature based on the first temperature. A first control processing unit for controlling heating by one heater,
The second heating control unit includes a second temperature sensor that measures the second temperature, a second heater that heats the second tube wall portion, and the second temperature based on the second temperature. A second control processing unit for controlling heating by the second heater,
The apparatus according to claim 1. The first heating for heating the first tube wall portion under a condition determined based on a difference between a first temperature measured at the first position and a predetermined first target temperature. A control unit;
A second temperature measured by the second position, advance-determined second determined conditions based on the difference between the target temperature, the second the second for heating the tube wall portions of the heating A control unit;
The apparatus according to claim 1, comprising: Preparing a device including a tube body in which a sound source is disposed at one end, a test body to be measured is disposed in a tube, and a sound pressure sensor is disposed between the sound source and the test body;
The first tube wall portion including the first position is heated under conditions determined based on a first temperature measured at a first position between the sound source of the tube main body and the test body. about,
In a condition determined based on a second temperature measured between a second position closer to the sound source than the first position between the sound source of the tube body and the test body, the second Heating the second tube wall part including the position,
Measure the sound pressure in the tube by the sound pressure sensor while radiating sound waves from the sound source toward the test body into the heated tube body, and based on the measurement result by the sound pressure sensor Evaluating the normal incidence acoustic properties of the specimen;
A normal incidence acoustic characteristic measuring method including: The first position is a position between the position of the surface of the test body on the sound source side and the sound pressure measurement position closest to the sound source of the sound pressure sensor,
The second position is a position between the sound pressure measurement position and the sound source.
The method of claim 7. The distance between the second position and the sound pressure measurement position is 25 mm or more.
The method of claim 8. The distance between the second position and the sound pressure measurement position is 500 mm or less.
10. A method according to claim 8 or 9. The device is
A first temperature sensor for measuring the first temperature, a first heater for heating the first tube wall portion, and heating by the first heater based on a measurement result by the first temperature sensor A first heating control unit including a first control processing unit for controlling
A second temperature sensor for measuring the second temperature, a second heater for heating the second tube wall portion, and heating by the second heater based on a measurement result by the second temperature sensor A second heating control unit including a second control processing unit for controlling
Including
The first heating wall is heated by the first heating controller,
Heating the second tube wall part by the second heating control unit;
The method according to claims 7 to 10. Heating the first tube wall portion under a condition determined based on a difference between a first temperature measured at the first position of the tube body and a first target temperature determined in advance;
Heating the second tube wall portion under a condition determined based on a difference between a second temperature measured at the second position of the tube body and a predetermined second target temperature;
12. A method according to claims 7-11.   A sound source is disposed at one end, a test body to be measured is disposed in the tube, and a tube body in which a sound pressure sensor is disposed between the sound source and the test body is first prepared, and then the tube body The first tube wall portion including the first position is heated under conditions determined based on a first temperature measured at a first position between the sound source and the test body. A condition determined based on a second temperature measured at a second position between the heating control unit and the sound source of the tube main body and the test body and closer to the sound source than the first position; A normal incidence acoustic characteristic measuring device manufactured by a method including providing a second heating control unit for heating the second tube wall portion including the second position.

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