JP6327389B1 - Resistance temperature detector and temperature sensor including the resistance temperature detector - Google Patents

Abstract

It is an object of the present invention to provide a resistance temperature detector capable of obtaining a compact, highly sensitive and highly responsive sensor at low cost, and a temperature sensor including the resistance temperature detector. SOLUTION: A plurality of element units 2,... Each having a resistance bulb element 21 incorporated in a metal tube 20 and a plurality of holding holes 30A / 30B into which the element units 2 are respectively inserted, are provided. Metal holding bodies 3A / 3B for holding the plurality of element units 2,... In the state of being arranged in the lateral direction intersecting each other in the axial direction by these holding holes, and each element on the base end side of the element unit 2 The lead wire 22 extended from the base end of the unit 2 is connected, and the connection part 4 which electrically connects the said several element unit 2 ... in series is provided. [Selection] Figure 2

Description

  The present invention relates to a resistance temperature detector and a temperature sensor that can be suitably used in a situation where high sensitivity and high responsiveness are required.

  The resistance thermometer has a structure in which a resistance thermometer element having a built-in resistance wire is housed in a metal tube, and various types are provided (see, for example, Patent Documents 1 to 3). In particular, a highly sensitive resistance temperature detector is required in the cryogenic temperature region of liquid hydrogen and liquid helium. As the resistance temperature detector element has a higher sensitivity as the resistance value of the resistance wire increases, such a resistance device (for example, an element having a resistance wire of Pt 1000Ω) is expensive and the resistance temperature detector. As a result, the responsiveness and design flexibility are limited.

JP 2015-219102 A JP2015-155829A Japanese Patent Laid-Open No. 2015-219047

  Therefore, in view of the above-mentioned situation, the present invention intends to solve a temperature measuring resistor capable of obtaining a compact, high-sensitivity, highly responsive one at low cost, and the temperature measuring resistor. The point is to provide a temperature sensor.

The present invention includes the following inventions.
(1) a plurality of element units in which resistance temperature detector elements are housed in a metal tube;
A plurality of holding holes into which each of the element units is inserted, and a metal holding body that holds the plurality of element units in a state of being arranged in a lateral direction crossing each other in the axial direction by the holding holes; Connecting a lead wire extending from the base end of each element unit on the base end side of the element unit and connecting the plurality of element units in series; Resistor.

  (2) A temperature sensor in which the resistance thermometer described in (1) is housed in a metal body.

  The temperature measuring resistor and the temperature sensor including the temperature measuring resistor according to the present invention as described above have a plurality of element units each including a temperature measuring resistor element built in an individual metal tube, and are horizontally placed by a metal holder. As well as being able to obtain the same high sensitivity compared to conventional resistance thermometers having a large resistance value resistance element, by holding them in a line-up state and electrically connecting them in series with each other, Since an element having a small resistance value is used, it is possible to obtain a reduction in cost, an improvement in responsiveness and an improvement in design freedom by downsizing. Specifically, for example, 10 commercially available inexpensive ultra-thin resistance thermometers (incorporating Pt 100Ω resistance thermometer elements) are connected in series as the above-mentioned element units, so that the surface area ratio does not change and the ultra-thin resistance thermometer While maintaining a high response speed that is the same as that of the resistor, a highly sensitive resistance temperature detector having a large resistance value can be obtained, and it is possible to provide a suitable temperature sensor for use in a cryogenic region of liquid hydrogen and liquid helium.

Explanatory drawing which shows a mode that an element unit is mounted | worn between metal holding bodies in the resistance temperature detector concerning typical embodiment of this invention. Similarly the longitudinal cross-sectional view of a resistance temperature detector. (A) is a cross-sectional view of a resistance temperature detector, and (b) is a cross-sectional view showing a modification. The conceptual diagram which shows the circuit which electrically connected the element unit in series. The longitudinal section which shows the temperature sensor which similarly incorporated the resistance temperature sensor. Similarly, an external view of a temperature sensor. The enlarged longitudinal cross-sectional view of the temperature sensor front-end | tip part enclosed with the dashed-dotted line of FIG.

  Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIGS. 1 to 4, a resistance temperature detector 1 according to the present invention includes a plurality of element units 2,. Has a plurality of holding holes 30A / 30B, and holds the plurality of element units 2,... In a state of being arranged in a lateral direction intersecting each other in the axial direction. 3A / 3B is connected to a lead wire 22 extending from the base end of each element unit 2 on the base end side of the element unit 2, and the plurality of element units 2,... Are electrically connected in series. 4 is provided.

  As shown in FIG. 2, the metal tube 20 constituting the element unit 2 is a cylindrical stainless steel tube whose tip is closed, and the resistance temperature detector element 21 is a wide range of conventionally known resistance temperature detector elements. Can be adopted. A lead wire 22 extending from the resistance temperature detector element 21 extends from the base end of the metal tube 20, and a clearance between the resistance temperature detector element 21 inside the metal tube 20 and the lead wire 22 and the inner peripheral surface of the metal tube 20. Is filled with an inorganic insulating powder such as alumina or magnesia or a filler 23 such as an epoxy resin to enhance the responsiveness. Such an element unit 2 can be a conventionally known sheath type resistance temperature detector.

  The metal holders 3A and 3B are for holding a plurality of element units 2 together, and as shown in FIGS. 1 and 3, both of them are formed of a circular metal plate. A plurality of the holding holes 30A, 30B penetrating in the axial direction, which is the thickness direction, are formed. The holding holes 30 </ b> A and 30 </ b> B are set to have the same inner diameter as the outer diameter of the metal tube 20 so that the metal tube 20 of the element unit 2 can be held. The metal tube 20 inserted into the holding holes 30A and 30B is fixed to the edge of each holding hole 30A and 30B by welding or the like.

  The metal holding body is constituted by a plate-like member having a thickness smaller than the outer diameter, but may be constituted by a block-like member having a thickness equal to or larger than the outer diameter. . Moreover, although both ends of the metal tube are supported by the two metal holders 3A and 3B, they may be supported at other positions, or supported by three or more or only one metal holder. You may have done. You may comprise with the block-shaped member which has the length covering the full length of the metal tube 20. FIG.

  A connecting rod 6 is provided between the two metal holders 3A and 3B. In this way, it is possible to avoid unnecessary force from being generated in each element unit 2 provided between the metal holders 3A and 3B by integrating the metal holders 3A and 3B with the connecting rod 6. In this example, three are provided at equal positions with respect to the center. The number is not particularly limited, and can be omitted when the element unit 2 alone can maintain the strength.

  The plurality of element units 2,... Are held side by side in parallel so that at least the built-in resistance temperature detector elements 21 have the same axial position. The number of element units 2 is 10 in this example, but can be determined according to the required specifications and is not particularly limited.

  Further, the arrangement of the element units 2 determined by the positions of the holding holes 30A and 30B is not particularly limited. In this example, the center of gravity is combined with the centers of the metal holding bodies 3A and 3B as shown in FIG. Although it arrange | positions equally in the area | region of an equilateral triangle, you may arrange | position equally to the whole metal holding bodies 3A and 3B like FIG.3 (b), for example. In addition, what arrange | positioned at predetermined intervals in the cyclic | annular area | region along the edge part of metal holding body 3A, 3B is also preferable.

  FIG. 4 is a conceptual diagram showing the state of a series connection circuit by the connection part 4. For example, the lead wire 22 extending from the base end of each element unit 2 and the cable 5 extending from the terminal part 95 of the temperature sensor 9 are shown. The lead wires 51 are connected to each other, and the lead wire 2 of the element unit 2 is connected in series to each other. Instead of the circuit board, the lead wires 22 may be directly connected to each other, and the lead wires 22 and the conductive wires 51 may be connected to each other to make the same series connection, and the contacts may be sealed with an insulating material such as resin.

  As shown in FIG. 2, the attachment structure of the connecting portion 4 is connected to the end of a connecting rod 6 that extends through the metal holder 3B and extends to the base end side opposite to the metal holder 3A. However, it is not limited to such a structure. For example, it is supported by a metal holder, a support supported on the inner peripheral surface of the intermediate sleeve 92, or a filler filled in the intermediate sleeve 92. Various structures are possible, such as those.

  Next, based on FIGS. 5-7, embodiment of the temperature sensor 9 incorporating the resistance temperature detector 1 is described.

  The temperature sensor 9 has the resistance thermometer 1 housed in a metal body 90. The temperature sensor 9 has a cylindrical shape with the tip of the metal body 90 opened. The metal body 90 is exposed to the outside while being flush with the tip of the metal body 90. A plurality of ventilation holes 91 are provided on the outer peripheral surface of the metal body 90, and the temperature measurement target fluid can be in direct contact with the outer surface of the metal tube 20 of each element unit 2 of the resistance temperature detector 1. Has been.

  As shown in FIG. 7, the outer peripheral surfaces of the metal holders 3A and 3B are set to have the same outer diameter as the inner diameter of the metal body 90 so as to be in close contact with the inner peripheral surface 90b of the cylindrical metal body 90. Thus, the resistance temperature detector 1 is held in a stable state in the metal body 90.

  As shown in FIG. 5, conductive wires 51 and 51 of the cable 5 extending from the terminal portion 95 are connected to the connection portion 4 of the resistance temperature detector 1, and a cylindrical intermediate sleeve 92 that covers the cable 5 and the connection portion 4 is further provided. Are further provided, and the inside is filled with an insulating material 93 such as an epoxy resin. The proximal end portion of the intermediate sleeve 92 is attached to the outer peripheral surface of the cable 5 via a sealing cylinder 94, and the distal end portion of the intermediate sleeve 92 passes through the metal holding body 3B and is opposite to the metal holding body 3A. Is inserted into the gap between the extending portion of the connecting rod 6 extending toward the base end side and the inner peripheral surface of the metal body 90.

  Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and can of course be implemented in various forms without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Resistance thermometer 2 Element unit 3A, 3B Metal holding body 4 Connection part 5 Cable 6 Connection rod 9 Temperature sensor 20 Metal pipe 21 Resistance temperature detector element 22 Lead wire 23 Filler 30A, 30B Holding hole 51 Conductor 90 Metal Made body 90a Tip portion 90b Inner peripheral surface 91 Vent hole 92 Intermediate sleeve 93 Filler 94 Sealing cylinder 95 Terminal portion

Claims (2)

A plurality of element units each including a resistance temperature detector element in a metal tube;
A plurality of holding holes into which the element units are respectively inserted, and a metal holding body for holding the plurality of element units in a state of being arranged in a lateral direction intersecting each other in the axial direction by the holding holes;
Connecting a lead wire extending from the base end of each element unit on the base end side of the element unit, and connecting the plurality of element units in series;
A resistance temperature detector characterized by comprising.   A temperature sensor comprising the resistance temperature detector according to claim 1 housed in a metal body.

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