JP2018151322A - Internal temperature measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique capable of accurately obtaining an internal temperature of an object to be measured. SOLUTION: It has a first surface and a second surface as outer surfaces facing each other, and when measuring the internal temperature of a measurement object, the first surface is located on the measurement object side, and the second surface is A heat transfer unit 121 located on the external environment side away from the measurement object, a measurement unit 122 for measuring the temperature on the first surface and the second surface of the heat transfer unit 121, and the heat transfer unit 121. The heat transfer unit is arranged at a position surrounding the outer periphery of the first surface and the second surface, and the influence of heat transferred from the measurement object to the external environment without passing through the heat transfer unit 121 can be ignored. It includes a heat insulating material 13 having a thermal resistance value higher than 121 or the same thermal resistance value as the heat transfer unit 121. [Selection diagram] Fig. 3

Description

  The present invention relates to an internal temperature measuring device that measures the internal temperature of an object to be measured.

  As an apparatus for measuring the deep body temperature, an apparatus using a heat flux sensor in which temperature sensors are respectively attached to upper and lower surfaces of a heat insulating material is known.

  FIG. 1 is an explanatory diagram for measuring a deep body temperature using a heat flux sensor. The heat flux sensor 12 illustrated in FIG. 1 includes a heat transfer unit (heat insulating member) 121 and a measurement unit 122 that measures the temperature difference between the upper surface and the lower surface of the heat transfer unit 121 and the temperature of the lower surface.

When measuring the deep body temperature, as shown in FIG. 1A, the heat flux sensor 12 has the lower surface of the heat flux sensor 12 in close contact with the body surface to be measured. At this time, the temperature Tr of the lower surface of the heat insulating material measured by the measuring unit 122 is lower than the deep body temperature Tb. Further, the temperature Ttop of the upper surface of the heat insulating material measured by the measuring unit 122 of the heat flux sensor 12 closely attached to the body surface is
It becomes lower than the temperature Tr. A heat equivalent circuit in which the difficulty of heat transfer at this time is shown as thermal resistance is expressed as shown in FIG. Rx is the thermal resistance value of the subcutaneous tissue that is a non-heating element, Rpkg is the thermal resistance value of the heat transfer section 121, and Rair is the external thermal resistance value when heat is released from the top surface of the heat insulating material to the outside air. is there.

  When the temperature of each part of the heat flux sensor in close contact with the body surface is stabilized, the amount of heat passing through the subcutaneous tissue (non-heating element) per unit time and the amount of heat passing through the heat transfer unit 121 per unit time become equal. That is, when the temperature of each part of the heat flux sensor is stabilized, the following expression (1) is established.

従って、熱流束センサの各部の温度が安定している場合、式（１）をＴｂについて解いた以下の式（２）により、深部体温Ｔｂを算出することができる。

Therefore, when the temperature of each part of the heat flux sensor is stable, the deep body temperature Tb can be calculated by the following formula (2) obtained by solving the formula (1) for Tb.

このように深部体温を算出する内部温度センサが例えば、特許文献１で提案されている。

For example, Patent Document 1 proposes an internal temperature sensor that calculates the deep body temperature.

Japanese Patent Laying-Open No. 2015-114291 Japanese Patent Laying-Open No. 2006-161311

なお、図２の例では、熱流束センサ１２の周囲には熱抵抗となるものがないので、Ｒpkg´＝０となり、内部温度Ｔｂの推定式は、式（４）のようになる。

式（４）では破線で囲んだ項に外部熱抵抗値Ｒairを含むことになり、この外部熱抵抗
値Ｒairが、熱流束センサ１２の周囲における対流や放射によって変化するので、これが
内部温度Ｔｂを推定する際の外乱要因となり、精度良く内部温度Ｔｂを推定できなくなるという問題がある。 As described above, when the amount of heat passing through the subcutaneous tissue per unit time is equal to the amount of heat passing through the heat transfer unit per unit time, and the equation (2) is satisfied, it is not affected by the external thermal resistance value Rair. But,
Actually, there is a heat flow Iy that escapes around the heat flux sensor 12, that is, in the lateral direction, as shown in FIG. Hereinafter, this phenomenon is also referred to as heat flux lateral escape. In a situation where this heat flow Iy is large and cannot be ignored, the heat resistance Ry for the heat flow Iy escaping in the lateral direction and the heat resistance value Rpkg ′ when the heat escaping in the lateral direction moves from the body surface to the outside are taken into consideration. The equation for estimating the temperature Tb is given by the equation (3
).

In the example of FIG. 2, since there is no thermal resistance around the heat flux sensor 12, Rpkg ′ = 0, and the estimation formula for the internal temperature Tb is as shown in Expression (4).

In the expression (4), an external thermal resistance value Rair is included in a term surrounded by a broken line, and this external thermal resistance value Rair changes due to convection and radiation around the heat flux sensor 12, and this changes the internal temperature Tb. There is a problem that it becomes a disturbance factor in estimation, and the internal temperature Tb cannot be estimated accurately.

  Therefore, an object of the present invention is to provide a technique that makes it possible to accurately determine the internal temperature of a measurement object.

  An internal temperature measuring device of the present invention for solving the above problems has a first surface and a second surface as outer surfaces facing each other, and when measuring the internal temperature of a measurement object, the first surface is The heat transfer part is located on the measurement object side, and the second surface is located on the external environment side away from the measurement object, and the temperature at the first surface and the second surface of the heat transfer part is measured. And the measurement unit that is disposed at a position surrounding the outer periphery of the first surface and the second surface of the heat transfer unit, and the influence of heat that moves from the measurement object to the external environment without passing through the heat transfer unit. And a heat insulating material having a heat resistance value higher than that of the heat transfer section or a heat resistance value equal to that of the heat transfer section.

  In this way, the heat insulating material is arranged adjacent to the heat transfer part, and the heat resistance value of the heat insulating material and the heat resistance value of the heat transfer part are made the same, thereby preventing the heat flux from escaping and the heat of the external environment. Since the internal temperature of the measurement object can be estimated without being affected by the resistance value, the internal temperature can be obtained with high accuracy. When the heat resistance value of the heat insulating material is set to a value slightly higher than the heat resistance value of the heat transfer section, a heat flux that flows laterally is generated compared to the case where no heat insulating material is provided, and this is the heat resistance of the external environment. Since it is influenced by the value, the internal temperature cannot be obtained with high accuracy. Therefore, by making the heat resistance value of the heat insulating material higher than the heat resistance value of the heat transfer part to such an extent that the influence of heat moving to the external environment can be ignored, the heat flux that escapes from the heat transfer part, or conversely, The heat flux flowing into the heat transfer section is within an allowable range, and the internal temperature can be obtained with high accuracy.

Moreover, the internal temperature measuring device of the present invention includes the second heat insulating material that covers the second surface of the heat transfer section, the first heat insulating material and the first heat insulating material as the first heat insulating material. You may set the heat resistance value of a 2nd heat insulating material higher than the said heat-transfer part.

  As a result, the heat flux that escapes sideways is reduced to a negligible level, and the internal temperature of the measurement object can be estimated without being affected by the thermal resistance value of the external environment, so that the internal temperature can be obtained with high accuracy.

  Moreover, the internal temperature measuring apparatus of this invention may be equipped with a waterproof layer between the surface of the said heat insulating material located in the said measurement object side at the time of the said measurement, and the said measurement object.

  Thereby, it can prevent that moisture adheres to a heat insulating material, heat insulation falls, and measurement accuracy falls.

  Moreover, the internal temperature measuring device of the present invention is provided between the surface of the heat insulating material positioned on the external environment side during the measurement and the external environment, and between the second surface of the heat transfer section and the external environment. A layer having a low infrared absorptance may be provided therebetween. Thereby, it can prevent that heat | fever flows in from the outside and a measurement precision falls.

  Moreover, the internal temperature measuring apparatus of this invention may comprise the heat flux sensor with which the said heat-transfer part and the said measurement part were manufactured by the MEMS process. Thereby, the thermal resistance of the heat flux sensor can be reduced, and the internal temperature can be obtained with high accuracy.

  Moreover, the internal temperature measuring device of the present invention includes a housing that accommodates the heat transfer unit, the measurement unit, and the heat insulating material, and when viewed from the normal direction of the first surface or the second surface. The outer shape of the heat insulating material and the outer shape of the housing containing the heat insulating material may be a circle or a polygon having five or more corners. Thereby, the outer shape of the heat insulating material is made the minimum necessary circle, or at least the polygon is closer to the circle than the rectangle (that is, the polygon more than the pentagon) is smaller than the rectangle, and the outer shape is included. Similarly, by reducing the outer shape of the housing, the contact area between the housing and the object to be measured is reduced, and heat flux escapes through the housing (lateral escape of heat flux) when measuring the internal temperature. The internal temperature can be obtained with high accuracy.

  According to the present invention, it is possible to accurately determine the internal temperature of the measurement object.

FIG. 1 is an explanatory diagram for measuring a deep body temperature using a heat flux sensor. FIG. 2 is an explanatory diagram of the heat flux that escapes laterally during measurement. FIG. 3 is a diagram illustrating a schematic configuration of the internal temperature measurement device according to the first embodiment. FIG. 4 is a plan view of the sensor unit. FIG. 5 is a diagram illustrating a thermal equivalent circuit according to the first embodiment. FIG. 6 is an explanatory diagram of a sensor unit according to the second embodiment. FIG. 7 is an explanatory diagram of a sensor unit according to the third embodiment. FIG. 8 is an explanatory diagram of a sensor unit according to the fourth embodiment. FIG. 9 is a diagram illustrating an example of a sensor module according to the fourth embodiment. FIG. 10 is a diagram illustrating a modification of the sensor module according to the fourth embodiment.

Hereinafter, specific embodiments to which the present technology is applied will be described with reference to the drawings.
<Embodiment 1>
FIG. 3 is a diagram showing a schematic configuration of the internal temperature measuring apparatus 10 according to the first embodiment of the present invention.
FIG. 3 is a plan view of the sensor unit 101. As shown in FIG. 3, the internal temperature measurement apparatus 10 includes a sensor unit 101 and a main body 102, and the sensor unit 101 and the main body 102 are electrically connected by a cable 103.

  The sensor unit 101 includes a housing 11, a heat flux sensor 12, a heat insulating material 13, an arithmetic circuit 14, and a terminal 15 disposed on the bottom 11 a of the housing 11. In the following description, “up”, “down”, “left”, and “right” of each part (heat flux sensor 12 and the like) mean “up”, “down”, “left”, and “right” of each part in the state shown in FIG. Also, the front side and the back side as viewed from the direction perpendicular to the paper surface of FIG. 3 are the front and rear, and the direction perpendicular to the vertical direction such as the front-rear direction and the left-right direction is also referred to as the horizontal direction. The internal temperature measuring apparatus 10 of this example is used by bringing the lower surface of the sensor unit 101 into contact with the surface of the measurement object.

  As shown in FIG. 4A, the casing 11 has a circular outer shape when viewed from above, in other words, the outer shape of the contact surface with the measurement object (XY plane in FIG. 4). The heat flux sensor 12 is disposed on the heat flux sensor 12, and a heat insulating material 13 having a circular outer shape is disposed around the heat flux sensor 12. The outer shape of the heat insulating material 13 is circular in this way, so that the minimum necessary range centering on the heat flux sensor 12 is insulated against heat moving upward from the contact surface with the measurement object. ing. Further, the outer shape of the heat insulating material 13 is not limited to a minimum circle, but may be a polygon closer to a circle than at least a rectangle (that is, a pentagon or more), and the outer shape may be smaller than a rectangle. As described above, the outer shape of the heat insulating material 13 is a circle or a polygon having five or more pentagons (FIG. 4B is an example of a hexagon), and the outer shape of the housing 11 that encloses the outer shape is also rectangular as shown in FIG. 4C. Compared to the case where it is formed, the contact area between the housing and the object to be measured is reduced, and the heat flux escapes through the housing when the internal temperature is measured (lateral escape of heat flux). Can be suppressed.

  In addition, when water enters the housing 11, accurate temperature measurement is hindered. Therefore, the housing 11 is desirably waterproof.

  Furthermore, it is desirable that the housing 11 includes a layer having a lower infrared absorption rate than the housing 11 or the heat insulating material 13 to enhance the heat insulating effect. For example, a metal thin film is formed by attaching a film 119 on which aluminum is vapor-deposited on the upper surface of the housing 11. Here, the layer having a low infrared absorption rate is a layer having an infrared absorption rate of 0.1 or less with respect to an infrared wavelength of about 10 μm. In the present embodiment, the infrared absorptance of the resin constituting the housing 11 is 0.95. By attaching the film 119 on which aluminum is deposited, the infrared absorptance of this portion is set to 0.025. ing.

  Further, the bottom 11a of the casing 11 is formed as thin as possible within a range where necessary rigidity can be obtained, and prevents heat flux from escaping to the outer side through the bottom 11a of the casing 11 during measurement. . Further, when the internal temperature measuring device 10 is a device used for measuring the internal temperature of a living body, that is, measuring body temperature, the bottom surface of the bottom portion 11a (contact surface with the living body) is brought into contact with the living body such as a smooth silicon sheet. A layer having biocompatibility with little irritation to the living body may be provided.

  The heat flux sensor 12 includes a heat transfer unit 121 and a measurement unit 122 that measures the heat flux transmitted from the lower surface (first surface) to the upper surface (second surface) of the heat transfer unit 121. The measuring unit 122 detects, for example, a temperature difference between the lower surface (hot contact) 22a and the upper surface (cold contact) 22b by a thermopile, and detects the temperature on the lower surface as a reference temperature. Not only this but the measurement part 122 measures the temperature in the lower surface (1st surface) and upper surface (2nd surface) of the heat-transfer part 121, respectively, and measures a heat flux by this temperature difference (temperature gradient). There may be.

The heat insulating material 13 is disposed at a position surrounding the outer periphery of the lower surface and upper surface of the heat transfer unit 121, that is, at a position adjacent to the heat transfer unit 121 in a direction orthogonal to the normal line of the lower surface and upper surface of the heat transfer unit 121.
In other words, it is adjacent to the side surface of the heat flux sensor 12, that is, the side surface of the heat transfer unit 121, and is provided on the bottom 11 a of the housing 11 so as to be flush with the lower surface of the heat transfer unit 121. The heat insulating material 13 is configured to have the same thermal resistance value as that of the heat transfer unit 121 of the heat flux sensor 12. For example, in this embodiment, the heat resistance is configured by using the resin having the same thermal conductivity as that of the heat transfer unit 121 of the heat flux sensor 12 so as to have the same thermal resistance value.

  The arithmetic circuit 14 is a circuit that calculates and outputs the internal temperature of the measurement object based on the measurement value input from the heat flux sensor 12. The calculation procedure of the internal temperature by the arithmetic circuit 14 will be described later. The arithmetic circuit 14 may be a single element (such as an integrated circuit) or a unit composed of a plurality of elements. Further, the arithmetic circuit 14 may be a programmable element / unit or a non-programmable element / unit.

  The terminal 15 is a connection part to which a power supply line and a signal line included in the cable 103 are connected.

  The main body 102 communicates with the sensor unit 101 via a signal line, thereby performing processing such as receiving a measurement result of the internal temperature from the sensor unit 101, and the received internal temperature (measurement). Display unit 222 for displaying the result), recording unit 223 for recording the internal temperature, operation unit 224 for performing measurement start operations, setting value input operations, and the like, and supplying power to the sensor unit 101 via the power line. The power supply unit 225 is provided.

The internal temperature measurement device 10 of this example is used by bringing the lower surface of the bottom 11a of the sensor unit 101 into contact with the surface of the internal temperature measurement object. That is, at the time of measurement, the lower surface (first surface) of the heat transfer unit 121 in the heat flux sensor 12 is positioned on the measurement object side, and the upper surface (second surface) is positioned on the external environment side away from the measurement object. . At this time, the temperature Tr on the lower surface of the heat transfer section 121 is lower than the internal temperature Tb. Further, the temperature Ttop on the upper surface of the heat transfer section 121 is the temperature Tr
Lower than. A thermal equivalent circuit in which the degree of heat reduction at this time, that is, the difficulty in transferring heat is shown as thermal resistance is expressed as shown in FIG. Rx is the thermal resistance value of the non-heating element located between the internal heat source and the surface, Rpkg is the thermal resistance value of the heat transfer section 121, Rpkg 'is the thermal resistance value of the heat insulating material 13, and Rair is It is the thermal resistance value of the external environment.

  When the temperature of each part of the sensor unit 101 brought into close contact with the measurement object is stabilized, the amount of heat passing through the non-heating element per unit time becomes equal to the amount of heat passing through the heat transfer part per unit time. That is, the internal temperature of the measurement object can be estimated based on the heat flux measured by the heat flux sensor 12. Here, of the heat flux I moving in the non-heat generating body, the internal temperature is estimated in consideration of the heat flux that moves in the lateral direction without passing through the heat transfer section 121 of the heat flux sensor 12, that is, the heat flux that escapes sideways. The expression becomes the following expression (5).

この場合、外部環境の熱抵抗値Ｒairは、外部環境の対流や放射の状況によって変動す
ることになるので、これを規定値として内部温度を求めると、精度良く内部抵抗を推定することができなくなってしまう。そこで、本実施形態では、断熱材１３を伝熱部１２１と同じ熱伝導率の材料を用いて構成し、断熱材１３の熱抵抗Ｒpkg´と伝熱部１２１の熱抵
抗Ｒpkgとを同一にしている。即ち、Ｒpkg´＝Ｒpkgなので、内部温度の推定式を次式（
６）のように表すことができる。

In this case, since the thermal resistance value Rair of the external environment varies depending on the convection and radiation conditions of the external environment, if the internal temperature is obtained using this as a specified value, the internal resistance cannot be accurately estimated. End up. Therefore, in this embodiment, the heat insulating material 13 is configured using a material having the same thermal conductivity as that of the heat transfer unit 121, and the heat resistance Rpkg ′ of the heat insulating material 13 and the heat resistance Rpkg of the heat transfer unit 121 are made the same. Yes. That is, since Rpkg ′ = Rpkg, the internal temperature estimation formula is
6).

このように本実施形態では、断熱材１３を熱流束センサ１２と隣接して配置し、断熱材１３の熱抵抗値と熱流束センサ１２（伝熱部１２１）の熱抵抗値を同じにしたことにより、横逃げする熱流束の横逃げを防止し、外部環境の熱抵抗値Ｒairの影響を受けずに測定
対象物の内部温度Ｔｂを推定できるので、精度良く内部温度Ｔｂを求めることができる。

Thus, in this embodiment, the heat insulating material 13 was arrange | positioned adjacent to the heat flux sensor 12, and the heat resistance value of the heat insulating material 13 and the heat resistance value of the heat flux sensor 12 (heat-transfer part 121) were made the same. Thus, the lateral escape of the heat flux that escapes laterally is prevented, and the internal temperature Tb of the measurement object can be estimated without being affected by the thermal resistance value Rair of the external environment, so that the internal temperature Tb can be obtained with high accuracy.

<Embodiment 2>
FIG. 6 is a diagram illustrating a configuration of the sensor unit 101 according to the second embodiment. The sensor unit 101 according to the second embodiment is provided with the second heat insulating material 23 that covers the upper surface of the heat transfer section 121 as compared with the first embodiment, and the heat resistance of the heat insulating materials 13 and 23 is set to the heat transfer section 121. The configuration is higher than the others, and the other configurations are the same. For this reason, in the second embodiment, the same elements as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted.

  In the first embodiment described above, the influence of the external environment is excluded by making the thermal resistance of the heat insulating material 13 and the heat resistance of the heat transfer section 121 the same, but for example, the heat of the heat insulating material 13 in the configuration of the first embodiment. When the resistance is set to a value slightly higher than that of the heat transfer section 121, a heat flux that flows laterally is generated as compared with the case where the heat insulating material 13 is not provided, and a disturbance factor is included. For this reason, even if it arrange | positions the heat insulating material 13 simply, the influence of the heat flux which moves to an external environment cannot be excluded.

  Therefore, in the second embodiment, the heat insulating material 23 is disposed on the upper surface of the heat flux sensor 12 (heat transfer unit 121), and the heat resistance of the heat insulating materials 13 and 23 is sufficiently higher than that of the heat transfer unit 121. The thermal equivalent circuit in this case is as shown in FIG. 6 and is expressed by the following equation (7).

In the second embodiment, the thermal resistance Rpkg ′ of the heat insulating materials 13 and 23 is sufficiently larger than the thermal resistance Rpkg of the heat flux sensor 12 as shown in the following formula (8).

For this reason, the thermal resistance when moving to the external environment via the heat flux sensor 12 is almost the same as the thermal resistance when moving to the external environment via the heat insulating material 13, and the heat flux that escapes laterally is negligible. Therefore, the internal temperature estimation formula can be approximated as the following formula (9).

Here, to sufficiently increase the thermal resistance of the heat insulating materials 13 and 23 is, for example, to set the thermal flux that escapes laterally within an allowable range by setting the thermal resistance Rpkg of the thermal flux sensor 12 to 5 times or more.

  When increasing the thermal resistance of the heat insulating materials 13 and 23, it is effective to use a foam material as the heat insulating materials 13 and 23. For example, the thermal conductivity of the sponge is about 0.03 [W / (m · K)], and when the heat transfer part 121 of the heat flux sensor 12 is formed of a resin or the like, the sponge is used as the heat insulating materials 13 and 23. By using this, the heat resistance of the heat insulating materials 13 and 23 can be made sufficiently larger than the heat resistance of the heat transfer section.

As described above, in the second embodiment, the heat insulating materials 13 and 23 are disposed around and on the upper surface of the heat flux sensor 12, and the heat resistance of the heat insulating materials 13 and 23 is sufficiently higher than that of the heat flux sensor 12 (heat transfer section 121). Therefore, the heat flux that escapes sideways is negligibly small, and the internal temperature Tb of the measurement object can be estimated without being affected by the thermal resistance value Rair of the external environment.
Can be requested.

<Embodiment 3>
FIG. 7 is a diagram illustrating a configuration of the sensor unit 101 according to the third embodiment. The sensor unit 101 of the second embodiment is different from the first embodiment in that the thermal resistance of the heat insulating material 13 is sufficiently larger than the thermal resistance value Rair of the external environment, and the other configurations are the same. is there.
For this reason, in the third embodiment, the same elements as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted.

As described above, when the thermal resistance of the heat insulating material 13 is set to a value slightly higher than that of the heat transfer section 121 in the configuration of the first embodiment, it is not possible to exclude the influence of the heat flux that flows laterally. Therefore, in the third embodiment, the heat resistance of the heat insulating material 13 is set to be sufficiently larger than the heat resistance value Rair of the external environment. The thermal equivalent circuit in this case is as shown in FIG. 7, and is represented by the following equation (10).

このように断熱材１３の熱抵抗Ｒpkg´を外部環境の熱抵抗値Ｒairよりも大きく設定すると、横方向から熱流束センサ１２へ流入する熱流束が存在することになるが、この熱流束は、式（１１）のように外部環境の熱抵抗値Ｒairを含まない式で近似できるので、外
乱要因を除去して内部温度を推定できる。 Here, in the third embodiment, the thermal resistance Rpkg ′ of the heat insulating material 13 is sufficiently increased with respect to the thermal resistance value Rair of the external environment, and the formula (10) can be transformed into the following formula (11). it can.

Thus, when the thermal resistance Rpkg ′ of the heat insulating material 13 is set to be larger than the thermal resistance value Rair of the external environment, there is a heat flux flowing into the heat flux sensor 12 from the lateral direction. Since it can be approximated by an expression that does not include the thermal resistance value Rair of the external environment as in Expression (11), the internal temperature can be estimated by removing the disturbance factor.

Here, to sufficiently increase the thermal resistance of the heat insulating material 13 is, for example, 5 to the thermal resistance value Rair.
The heat flux flowing into the heat flux sensor 12 is set within an allowable range.

When the thermal resistance of the heat insulating material 13 is increased, it is effective to use a foam material as the heat insulating material 13. For example, the thermal resistance of the sponge is about 0.03 [W / (m · K)]. By using the sponge as the heat insulating material 13, the heat resistance of the heat insulating material 13 is set to the heat resistance value Rair of the external environment. Can be large enough.

As described above, in the third embodiment, the thermal resistance of the heat insulating material 13 is sufficiently higher than the thermal resistance value Rair of the external environment. Therefore, the internal temperature Tb of the measurement object is not affected by the thermal resistance value Rair of the external environment. Therefore, the internal temperature Tb can be obtained with high accuracy.

<Embodiment 4>
FIG. 8 is a diagram illustrating a configuration of the sensor unit 101 according to the fourth embodiment. The internal temperature measurement device 10 of the fourth embodiment is different from the second embodiment in the configuration in which the heat flux sensor 12 is replaced with a heat flux sensor (hereinafter also referred to as a MEMS chip) 120 formed by a MEMS process. Other configurations are the same. For this reason, in the fourth embodiment, the same elements as those in the above-described second embodiment are denoted by the same reference numerals, and the description thereof is omitted. In the fourth embodiment, the heat flux sensor 12 of the second embodiment is replaced with the MEMS chip 120. However, the heat flux sensor 12 of the first and third embodiments may be replaced with the MEMS chip 120.

  FIG. 9 is a diagram illustrating a configuration of the sensor module 220 of the fourth embodiment. The sensor module 220 includes a MEMS chip 120 on which a semiconductor substrate 32 such as silicon is provided on a substrate 31 and a measurement unit 33 such as a thermopile is formed on the semiconductor substrate 32 by a MEMS process. The measurement unit 33 detects the temperature difference between the lower surface (hot contact) 32a and the upper surface (cold contact) 32b of the semiconductor substrate 32 and the temperature at the lower surface. In the fourth embodiment, the semiconductor substrate 32 is a form of the heat transfer unit.

  The housing 36 is disposed on the base material 121 so as to accommodate the MEMS chip 120 therein. Since the housing 36 stably measures the heat flux by the MEMS chip 120, the housing 36 prevents air from entering and leaving the housing 36. Further, the housing 36 may be omitted.

  An arithmetic circuit 34 and a terminal 35 are provided on the substrate 31. The arithmetic circuit 34 is a circuit that calculates and outputs the internal temperature of the measurement object based on the measurement value input from the MEMS chip 120. The calculation procedure of the internal temperature by the arithmetic circuit 34 is the same as that of the arithmetic circuit 14 described above. The terminal 35 is a connection part to which a power supply line and a signal line included in the cable 103 are connected. Communication with the main body 102 is performed via the terminal 35 and the cable 103, and the main body 102 performs processing such as receiving a measurement result of the internal temperature from the sensor unit 101.

  The sensor module 220 including the MEMS chip 120, the arithmetic circuit 34, the terminal 35, and the housing 36 on the substrate 31 is accommodated in the housing 110. Further, a heat insulating material 13 is provided around the MEMS chip 120, that is, around the housing 36, and a heat insulating material 23 is provided above the housing 36.

  The housing 110 has a predetermined rigidity so as to protect the sensor module 220 and the heat insulating materials 13 and 23 from an impact during use, and to maintain the positional relationship between the sensor module 220 and the heat insulating materials 13 and 23. The casing 110 may employ a foamed material or a hollow structure in order to increase thermal resistance and reduce heat escape.

  In addition, when water enters the housing 110, accurate temperature measurement is hindered. Therefore, the housing 110 is desirably waterproof. In the case of using a foam material for the heat insulating materials 13 and 23, it is particularly desirable that the housing 110 is waterproof since the heat insulating properties are impaired when the heat insulating materials 13 and 23 contain water.

  Furthermore, it is desirable that the housing 110 includes a layer having a low infrared absorptance to enhance a heat insulating effect. For example, a metal thin film is formed by attaching a film 119 on which aluminum is vapor-deposited on the upper surface of the housing 110. Here, the layer having a low infrared absorption rate is a layer having an infrared absorption rate of 0.1 or less with respect to an infrared wavelength of about 10 μm. In this embodiment, the infrared absorptance of the resin constituting the housing 110 is 0.95. By attaching the film 119 on which aluminum is deposited, the infrared absorptance of this portion is set to 0.025. ing.

  Further, the bottom 110a of the housing 110 is formed as thin as possible in order to increase the thermal resistance in the lateral direction and prevent the lateral escape of the heat flux.

  Note that the sensor unit 101 is not limited to a configuration in which the sensor module 220 and the heat insulating materials 13 and 23 are housed in a highly rigid housing, but can be disposed around the sensor module 220 and the heat insulating materials 13 and 23 as shown in FIG. It is good also as a structure which provided the flexible film.

  In the example of FIG. 10, a waterproof film 118 is attached to the lower surface of the heat insulating material 13 and the sensor module 220 and the periphery of the heat insulating material 13. In addition, an aluminum vapor deposition film 119 that is waterproof and has a low infrared absorptivity is attached to the upper surfaces of the heat insulating materials 13 and 23. By using a film that covers the heat insulating material 13 and the sensor module 220 as shown in FIG. 10, it is possible to increase the thermal resistance against the heat flux that escapes in the lateral direction during measurement, and to suppress the lateral escape of the heat flux.

  Further, according to the embodiment, since the heat flux sensor is the MEMS chip 120 formed by MEMS, the heat resistance Rm of the heat flux sensor is equal to the heat resistance Rpkg of the heat flux sensor 12 in the first to third embodiments or the heat insulation. Since the heat resistance Rpkg ′ of the materials 13 and 23 is very small, the lateral escape of the heat flux can be effectively prevented, and the internal temperature can be obtained with high accuracy.

  The above-described embodiments and modifications of the present invention are merely examples, and the present invention is not limited thereto. The characteristic configurations shown in the above-described embodiments and modifications can naturally be combined without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 10 Internal temperature measuring device 11 Housing | casing 11a Bottom part 12 Heat flux sensor 13, 23 Heat insulating material 14 Arithmetic circuit 15 Terminal 221, Control part 222 Display part 223 Recording part 224 Operation part 225 Power supply part 101 Sensor unit 102 Main body 103 Cable

Claims (6)

There are a first surface and a second surface as outer surfaces facing each other, and when measuring the internal temperature of the measurement object, the first surface is positioned on the measurement object side, and the second surface is the measurement object A heat transfer section located on the external environment side away from
A measuring unit for measuring temperatures on the first surface and the second surface of the heat transfer unit;
It is arranged at a position surrounding the outer circumferences of the first surface and the second surface of the heat transfer part, and to the extent that the influence of heat moving from the measurement object to the external environment without passing through the heat transfer part can be ignored. A heat resistance value higher than the heat transfer part, or a heat insulating material having the same heat resistance value as the heat transfer part,
An internal temperature measuring device comprising:   The heat insulating material is a first heat insulating material, and a second heat insulating material that covers the second surface of the heat transfer section is provided, and the heat resistance values of the first heat insulating material and the second heat insulating material are transmitted. The internal temperature measuring device according to claim 1 set higher than a heat part.   The internal temperature measurement device according to claim 1 or 2, further comprising a waterproof layer between the surface of the heat insulating material positioned on the measurement object side during the measurement and the measurement object.   Infrared absorptivity than the heat insulating material between the surface of the heat insulating material positioned on the external environment side during the measurement and the external environment, and between the second surface of the heat transfer section and the external environment. The internal temperature measuring device according to any one of claims 1 to 3, further comprising a low layer.   The internal temperature measurement device according to any one of claims 1 to 4, wherein the heat transfer unit and the measurement unit constitute a heat flux sensor manufactured by a MEMS process. A housing that houses the heat transfer unit, the measurement unit, and the heat insulating material;
The outer shape of the heat insulating material when viewed from the normal direction of the first surface or the second surface and the outer shape of the housing that encloses the outer shape are a circle or a pentagon or more polygon. The internal temperature measuring device according to any one of the above.

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