JP2007057430A - Contact-type thermometer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a contact-type thermometer, which measures the surface temperature of a test object with a thermocouple joining two kinds of metal wires at a junction, and also measures the surface temperature of a test object with high precision. <P>SOLUTION: The contact-type thermometer 1 is equipped with: a thermocouple 11 two kinds of metal wires are joined at a junction MP; a supporting member 13 supporting a temperature measuring part 113 of the thermocouple 11 at a flat butting part 131, a cylindrical body 12 engaging an end of the supporting member 13; and a sheet-like member 14 affixed to the side facing to the butting part 131, interleaving the temperature measuring part 113. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a contact-type thermometer that measures the temperature of a surface to be measured by a thermocouple in which two types of metal wires are joined at a joint.

Conventionally, there has been a demand for high accuracy for a contact-type thermometer that measures the temperature of a surface to be measured by a thermocouple in which two types of metal wires are joined at a joint, and various proposals have been made. . For example, a contact plate provided with support bars at both ends is fixed to an annular elastic member formed by connecting both ends of an elastic plate, and a temperature sensing part (= thermocouple) is provided between the annular elastic member and the contact plate. And a support body holding the opposite side of the annular elastic member opposite to the part to which the contact plate is attached, and further supporting the support bar in parallel with the temperature-measuring body with which the contact plate contacts. In the state where the annular elastic member is elastically deformed so as to be slightly flat, it is supported by applying an elastic force to the back surface of the contact plate. A contact thermometer is disclosed (see Patent Document 1).
Japanese Patent Laid-Open No. 10-318854

  In the above contact-type thermometer, the contact plate is supported through the guide hole in a state in which the elastic member formed in an annular shape (original shape is circular) is pressed and elastically deformed to be slightly flat. Even if it is intended to move laterally in contact with the surface of the moving object, it acts to hold the contact plate in its original position by the elastic force generated on the curved surface formed in the opposite direction on the side of the elastic member. In addition, since the central portion of the contact plate is always pressed in a convex shape so as to bulge toward the temperature-measured body, the temperature-sensing portion can be accurately pressed against the surface of the moving object. The temperature can be measured accurately.

  However, the amount of heat dissipated due to heat conduction from the temperature-measuring body cannot be ignored via the temperature sensing part (thermocouple) etc. that is in contact with the surface of the temperature-measurement body. In doing so, the temperature of the surface of the temperature object to be measured may be lowered, resulting in a measurement error.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a contact-type thermometer that measures the temperature of the surface of the object to be measured with high accuracy.

  The contact thermometer according to claim 1 includes a thermocouple in which two types of metal wires are joined at a joint portion, and a support member that supports the thermocouple, and the support member covers the thermocouple. It has a contact part that is pressed against the surface of the temperature measuring body, and a temperature measurement part that is within a predetermined length from the junction of the thermocouple is positioned and supported on the contact part.

  According to said structure, the supporting member which supports a thermocouple has a contact part which press-contacts a thermocouple to the surface of a to-be-measured body, and this contact part is a predetermined length from the junction part of a thermocouple. Since the temperature measurement part which is the range is located and supported, the temperature measurement part is reliably pressed against the surface of the temperature measurement object, and the temperature of the surface of the temperature measurement object is measured with high accuracy.

  The contact-type thermometer according to claim 2 is characterized in that each thermocouple of the thermocouple has a predetermined diameter or less.

  According to said structure, since each metal wire of a thermocouple is below a predetermined diameter, the quantity of heat radiated | emitted from a to-be-measured body through each metal wire of a thermocouple is reduced, and the temperature of the to-be-measured body surface Is measured with higher accuracy.

  According to a third aspect of the present invention, the thermocouple is characterized in that each metal wire is made of a material having low thermal conductivity.

  According to the above configuration, since each metal wire of the thermocouple is made of a material having low thermal conductivity, the amount of heat radiated from the temperature-measured body via each metal wire of the thermocouple is further reduced, and the temperature-measured body The surface temperature is measured with higher accuracy.

  The contact-type thermometer according to claim 4 is characterized in that the thermocouple is chromel-alumel.

  According to said structure, since a thermocouple is a chromel-alumel, the thermocouple whose each metal wire is low thermal conductivity is implement | achieved.

  The contact-type thermometer according to claim 5 is characterized in that each metal wire of the temperature measuring portion is formed in a spiral shape.

  According to said structure, since each metal wire of a temperature measurement part is formed in the spiral shape, the area of the contact part which supports a temperature measurement part can be reduced, and a contact-type thermometer can be reduced in size.

  The contact-type thermometer according to claim 6 is characterized in that the support member is made of a heat insulating material.

  According to said structure, since a supporting member consists of a heat insulating material, the amount of heat radiated | emitted from a to-be-measured body through the supporting member which supports a temperature-measurement part is further reduced, and the temperature of to-be-measured body surface further Measured with high accuracy.

  The contact-type thermometer according to claim 7 is provided with a sheet-like member made of a material having high thermal conductivity, which is affixed to a side facing the contact part with the temperature measurement part interposed therebetween.

  According to the above configuration, since the sheet-like member made of a material having high thermal conductivity is attached to the side facing the contact part across the temperature measurement part, the heat of the surface of the temperature-measured body is the sheet-like member. Is efficiently transmitted to the temperature-measuring site, and the temperature of the surface of the temperature-measuring object is measured with higher accuracy.

  The contact-type thermometer according to claim 8 is characterized in that at least one of the support member and the sheet-like member has elasticity.

  According to said structure, since at least one of a support member and a sheet-like member has elasticity, the contact area of a to-be-measured body surface and a sheet-like member increases, and the heat | fever of the to-be-measured body surface heats a sheet-like member The temperature is more efficiently transmitted to the temperature-measuring region via the temperature sensor, and the temperature of the surface of the temperature-measuring object is measured with higher accuracy.

  The contact-type thermometer according to claim 9 is characterized in that the sheet-like member is made of silicone rubber.

  According to said structure, since a sheet-like member consists of silicone rubber, a highly heat-conductive and elastic sheet-like member is easily implement | achieved.

  According to the first aspect of the present invention, the support member that supports the thermocouple has an abutting portion that presses the thermocouple against the surface of the temperature-measured body. Since the temperature measurement part which is the range for the predetermined length is positioned and supported, the temperature measurement part is reliably pressed against the surface of the temperature measurement object, and the temperature of the temperature measurement object surface can be measured with high accuracy.

  According to invention of Claim 2, since each metal wire of a thermocouple is below a predetermined diameter, the calorie | heat amount radiated | emitted from a to-be-measured body through each metal wire of a thermocouple is reduced, and temperature to be measured The temperature of the body surface can be measured with higher accuracy.

  According to the invention of claim 3, since each metal wire of the thermocouple is made of a material having low thermal conductivity, the amount of heat radiated from the temperature-measured body via each metal wire of the thermocouple is further reduced, It is possible to measure the temperature of the surface to be measured with higher accuracy.

  According to the invention described in claim 4, since the thermocouple is chromel-alumel, it is possible to realize a thermocouple in which each metal wire has low thermal conductivity.

  According to the invention described in claim 5, since each metal wire is formed in a spiral shape in the temperature measuring portion, the area of the contact portion supporting the temperature measuring portion is reduced, and the contact thermometer is downsized. it can.

  According to the sixth aspect of the present invention, since the support member is made of a heat insulating material, the amount of heat radiated from the temperature-measured body through the support member that supports the temperature measurement site is further reduced, and the surface of the temperature-measurement body Is measured with higher accuracy.

  According to the invention described in claim 7, since the sheet-like member made of a material having high thermal conductivity is attached to the side facing the contact part across the temperature measurement part, the heat of the surface to be measured is measured. Is efficiently transmitted to the temperature measuring part via the sheet-like member, and the temperature of the surface of the temperature-measured body can be measured with higher accuracy.

  According to the invention described in claim 8, since at least one of the support member and the sheet-like member has elasticity, the contact area between the surface of the temperature-measured body and the sheet-like member is increased, and the temperature of the surface of the temperature-measured body is increased. Is more efficiently transmitted to the temperature measuring part via the sheet-like member, and the temperature of the surface of the temperature-measured body can be measured with higher accuracy.

  According to the invention described in claim 9, since the sheet-like member is made of silicone rubber, a sheet-like member having high thermal conductivity and elasticity can be easily realized.

  FIG. 1 is a perspective view showing an example of a contact-type thermometer according to the present invention. FIG. 2 is a bottom view and a side view of the contact thermometer shown in FIG. The configuration of the contact thermometer will be described below with reference to FIGS. The contact-type thermometer 1 includes a thermocouple 11 in which two kinds of metal wires are joined at a joint MP, a support member 13 that supports a temperature measuring portion 113 of the thermocouple 11 at a flat contact portion 131, and a support A cylindrical body 12 that locks one end of the member 13 and a sheet-like member 14 that is affixed to the side facing the contact portion 131 across the temperature measurement portion 113 are provided.

  In the thermocouple 11, each of the metal wires 111 and 112 is made of a material having a low thermal conductivity (here, chromel (alloy of Ni and Cr) -alumel (alloy of Ni and Al)), and each metal wire (chromel wire). 111 and alumel wire 112) have a predetermined diameter (for example, a diameter of 1 mm) or less (for example, a diameter of 0.5 mm). A temperature measuring portion 113 having a predetermined length (for example, 10 mm) or more (for example, 20 mm) from the joint portion MP of the chromel wire 111 and the alumel wire 112 is formed in a spiral shape, and is a contact portion of the support member 13. 131 is supported. The thermocouple 11 is connected to a voltmeter (not shown), and the temperature of the surface of the measured object is measured based on the voltage value measured by the voltmeter.

  The support member 13 is made of, for example, a heat insulating material such as glass fiber formed in a substantially cylindrical shape, and one end portion (here, the upper end portion) is fitted and locked to the cylindrical body 12 and the other end portion ( Here, the contact part 131 which is the lower end part) supports the temperature measurement part 113 of the thermocouple 11.

  The cylindrical body 12 is made of, for example, an insulating material such as a resin formed in a substantially cylindrical shape, and is supported by being fitted with a support member 13 at one end (here, the lower end). Further, the chromel wire 111 and the alumel wire 112 of the thermocouple 11 supported by the support member 13 penetrate the cylindrical body 12 and are connected to a voltmeter (not shown).

  The sheet-like member 14 is brought into contact with the surface of the temperature-measuring body and transmits the temperature of the surface of the temperature-measuring body to the temperature-measurement portion 113 of the thermocouple 11 and has a film-like elasticity and high thermal conductivity. These materials (for example, silicone rubber) are attached to the temperature measuring portion 113 of the thermocouple 11 on the side facing the contact portion 131 of the support member 13.

  FIG. 3 is a side view showing an example of a test apparatus for evaluating the characteristics of the contact thermometer 1 according to the present invention. The test apparatus includes a hot plate 3 that can be heated to a predetermined temperature, a temperature-measured body 2 disposed on the hot plate 3, and a reference thermometer 4 that measures the temperature of the upper surface of the temperature-measured body 2. I have. Further, as shown in the figure, in the contact thermometer 1 (or the conventional contact thermometer 100), a sheet-like member 14 (not shown) is pressed against the upper surface of the temperature-measuring body 2, and the reference thermometer 4 The accuracy and the like are evaluated by comparing with a measured value (hereinafter referred to as a reference temperature).

  The object to be measured 2 is an object whose surface temperature is measured by the contact-type thermometer 1 (for example, a printed wiring board), and is placed on the upper surface of the hot plate 3 and has a predetermined temperature (here, 107 ° C.).

  The hot plate 3 is made of a metal plate or the like in which a heating wire is embedded, and can control the temperature of the object to be measured 2 placed on the upper surface to a predetermined temperature by controlling the amount of generated heat. is there.

  The reference thermometer 4 has a thermocouple 41 for measuring the reference temperature, and a metal putty 42 for bonding the joint portion of the thermocouple 41 to abut the upper surface of the temperature-measured body 2. It is connected to an abbreviated voltmeter, and the reference temperature on the surface of the temperature object is measured based on the voltage value measured by this voltmeter.

  4 and 5 are graphs showing examples of characteristics of the contact thermometer 1 measured using the test apparatus shown in FIG. 4 and 5, the horizontal axis represents time t, and the vertical axis represents temperature TS. Graphs G11 and G21 are graphs showing changes in temperature measured by the contact-type thermometer 1 when the contact-type thermometer 1 is pressed against the surface of the temperature-measured body 2 at the time t0. Graphs G14 and G24 are graphs showing changes in temperature measured by the reference thermometer 4. FIG. 5 is an enlarged view of the vertical axis of FIG.

  6 and 7 are graphs showing examples of characteristics of the conventional contact thermometer 100 measured using the test apparatus shown in FIG. 6 and 7, the horizontal axis represents time t, and the vertical axis represents temperature TS. Graphs G31 and G41 show changes in temperature measured by the conventional contact thermometer 100 when the conventional contact thermometer 100 is pressed against the surface of the temperature-measuring body 2 at the time t1. The graphs G34 and G44 are graphs showing changes in temperature measured by the reference thermometer 4. FIG. 7 is an enlarged view of the vertical axis of FIG.

  As shown in FIGS. 6 and 7, in the conventional contact thermometer 100, heat radiation through a thermocouple or the like disposed in the contact thermometer 100 is large when pressed against the surface of the temperature-measured body 2. When the contact-type thermometer 100 is brought into pressure contact with the surface of the body 2 to be measured, the temperature drop ΔT4 (= 4.5 ° C.) of the reference temperature measured by the reference thermometer 4 is large and 100 seconds. An offset amount ΔT3 (= 2 to 3 ° C.) that cannot be ignored even after the above period remains.

  On the other hand, as shown in FIGS. 4 and 5, in the contact thermometer 1 according to the present invention, since the heat radiation through the contact thermometer 1 is small, the contact thermometer 1 is to be measured 2. The temperature drop ΔT2 (= 2.3 ° C.) of the reference temperature at the time when it is pressed against the surface is halved, and the offset with respect to the reference temperature becomes substantially zero in about 10 seconds.

  In this way, the support member 13 that supports the thermocouple 11 has the contact portion 131 that presses the thermocouple 11 against the surface of the temperature-measured body 2, and the contact portion 131 has a joining portion of the thermocouple 11. Since the temperature measuring part 113 having a predetermined length (for example, 20 mm) from the MP is positioned and supported, the temperature measuring part 113 is surely pressed against the surface of the temperature measuring body 2 and the surface of the temperature measuring body 2 is Temperature is measured with high accuracy.

  Moreover, since each metal wire 111,112 of the thermocouple 11 is below predetermined diameter (here 0.5 mm), it radiates | emits heat from the to-be-measured body 2 via each metal wire 111,112 of the thermocouple 11. The amount of heat is reduced, and the temperature of the surface of the object to be measured 2 is measured with higher accuracy.

  Further, since the metal wires 111 and 112 of the thermocouple 11 are made of a material having a low thermal conductivity (here, chromel-alumel), heat is radiated from the temperature-measured body 2 via the metal wires 111 and 112 of the thermocouple 11. The amount of heat generated is further reduced, and the temperature of the surface of the to-be-measured body 2 is measured with higher accuracy.

  In addition, since the metal wires 111 and 112 of the temperature measurement part 113 are formed in a spiral shape, the area of the contact part 131 that supports the temperature measurement part 113 is reduced, and the contact thermometer 1 is downsized. obtain.

  In addition, since the support member 13 is made of a heat insulating material, the amount of heat radiated from the temperature-measured body 2 through the support member 13 that supports the temperature measurement portion 113 is further reduced, and the temperature of the surface of the temperature-measurement body 2 is further increased. Measured with high accuracy.

  Furthermore, since the sheet-like member 14 made of a highly heat-conductive material is attached to the side facing the contact part 131 with the temperature measurement part 113 in between, the heat on the surface of the temperature-measured body 2 is heated to the sheet-like member 14. Is efficiently transmitted to the temperature measuring portion 113, and the temperature of the surface of the temperature measuring object 2 is measured with higher accuracy.

  In addition, since the sheet-like member 14 has elasticity, the contact area between the surface of the temperature-measured body 2 and the sheet-like member 14 is increased, and the heat of the surface of the temperature-measured body 2 is further improved through the sheet-like member 14. Therefore, the temperature is transmitted to the temperature measuring portion 113, and the temperature of the surface of the temperature measuring body 2 is measured with higher accuracy.

  In addition, this invention can take the following forms.

  (A) Although the case where the thermocouple 11 is chromel-alumel has been described in the present embodiment, other types of materials may be used as long as the material has low thermal conductivity.

  (B) In this embodiment, although the case where the wire diameter of each metal wire 111 and 112 of the thermocouple 11 is 0.5 mm in diameter was demonstrated, it should just be below a predetermined diameter (for example, diameter 1mm). The smaller the wire diameter of each metal wire 111, 112, the smaller the amount of heat dissipated through each metal wire 111, 112, so that highly accurate measurement is possible.

  (C) In the present embodiment, the case where the temperature measurement portion 113 of the thermocouple 11 is 20 mm from the joint MP has been described, but it may be an appropriate dimensional length of a predetermined length (for example, 100 mm) or more. Since the measurement accuracy improves as the temperature measurement region 113 is longer, the length of the temperature measurement region 113 may be set according to the required measurement accuracy.

  (D) In the present embodiment, the case where the temperature measuring portion 113 of the thermocouple 11 is formed in a spiral shape has been described. However, if a dimensional length of a predetermined length (for example, 100 mm) or more can be secured, it is formed in another shape. It may be in the form. For example, the shape formed in U shape, V shape, U shape, etc. may be sufficient.

  (E) In this embodiment, although the case where the supporting member 13 consists of glass fiber was demonstrated, the form which consists of another heat insulating material may be sufficient.

  (F) In this embodiment, although the case where the sheet-like member 14 consists of silicone rubber was demonstrated, the form which consists of another highly heat conductive material may be sufficient.

  (G) In this embodiment, although the case where the sheet-like member 14 has elasticity was demonstrated, at least one of the support member 13 and the sheet-like member 14 should just be a form which has elasticity.

It is a perspective view which shows an example of the contact-type thermometer which concerns on this invention. It is the bottom view and side view of a contact-type thermometer shown in FIG. It is a side view which shows an example of the test apparatus which evaluates the characteristic of the contact-type thermometer which concerns on this invention. It is a graph which shows an example of the characteristic of the contact-type thermometer measured using the test apparatus shown in FIG. 5 is a graph (an enlarged graph of the vertical axis in FIG. 4) showing an example of the characteristics of a contact thermometer measured using the test apparatus shown in FIG. 3. It is a graph which shows an example of the characteristic of the conventional contact-type thermometer measured using the test apparatus shown in FIG. It is the graph (graph which expanded the vertical axis | shaft of FIG. 6) which shows an example of the characteristic of the conventional contact-type thermometer 100 measured using the test apparatus shown in FIG.

Explanation of symbols

1 Contact Thermometer 11 Thermocouple 111 Chromel Wire (Metal Wire)
112 Alumel wire (metal wire)
113 Temperature measuring part 12 Cylindrical body 13 Support member 131 Contact part 14 Sheet-like member MP Joining part

Claims (9)

A thermocouple in which two types of metal wires are joined at the joint,
A support member for supporting the thermocouple,
The support member has a contact portion that presses the thermocouple against the surface of the temperature-measured body, and a temperature measurement portion that is a predetermined length from the junction of the thermocouple is positioned at the contact portion. A contact-type thermometer characterized by being supported.   The contact thermometer according to claim 1, wherein each thermocouple has a metal wire having a predetermined diameter or less.   The contact thermometer according to claim 1, wherein each of the metal wires is made of a material having low thermal conductivity.   The contact thermometer according to claim 3, wherein the thermocouple is chromel-alumel.   The contact thermometer according to any one of claims 1 to 4, wherein each of the temperature measuring parts is formed in a spiral shape with each metal wire.   The contact-type thermometer according to claim 1, wherein the support member is made of a heat insulating material.   The contact-type temperature according to any one of claims 1 to 6, further comprising a sheet-like member that is affixed to a side facing the contact part with the temperature measurement part interposed therebetween, and is made of a material having high thermal conductivity. Total.   The contact thermometer according to claim 7, wherein at least one of the support member and the sheet-like member has elasticity.   The contact-type thermometer according to claim 7, wherein the sheet-like member is made of silicone rubber.

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