JP3683664B2 - thermocouple - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a consumable thermocouple used for temperature measurement such as molten metal temperature.
[0002]
[Prior art]
Conventionally, as shown in FIG. 4, this type of thermocouple has a thermocouple wire 102 and an electrode terminal 103 connected to the thermocouple wire 102 at one open end of a thermocouple outer tube 101 made of a paper tube having both ends opened. , 103 and a thermocouple provided with lead wires 105, 105 and electrode terminal contacts 106, 106 connected to the lead wires 105, 105 on the other opening end side of the thermocouple outer tube 101. A plug 107 is inserted, and a ceramic sheet 108 is thinly wound around the outer peripheral surface of the thermocouple outer tube 101, and the electrode terminals 103 and 103 of the thermocouple chip 104 and the electrode terminal contacts 106 and 106 of the thermocouple plug 107 are inside. And are electrically connected to each other.
[0003]
Therefore, the molten metal is immersed in molten metal at 1000 to 1500 ° C. for 2 or 3 seconds so that the thermocouple wire 102 is on the lower side and the lower portion of the thermocouple outer tube 101 is partially immersed. The thermocouple 100 after measurement is burned and burned because the thermocouple outer tube 101 is formed of paper, so that it is discarded as it is.
[0004]
[Problems to be solved by the invention]
As described above, although the consumable thermocouple is held down at a relatively low manufacturing cost, there is a problem that the total cost is high because it is discarded by one-time measurement.
[0005]
When measuring, if the thermocouple 100 is immersed deeply in the molten metal M, the electrode terminals 103 and 103 connected to the thermocouple wire 102 and the electrode terminal contacts 106 connected to the conducting wires 105 and 105 inside the thermocouple outer tube 101. , 106 are provided, there is a risk that an unnecessary temperature is applied to this connection point, resulting in a measurement error. For this reason, skill is required for the measurement so that the thermocouple 100 is not so deeply immersed in the molten metal M.
Therefore, the present invention has been made to solve the above-mentioned problems, and aims to provide a thermocouple that can be used several times to reduce the total cost and that does not require skill in measurement. It is.
[0006]
[Means for Solving the Problems]
In order to achieve this object, the present invention is to fit a thermocouple chip having a thermocouple wire and an electrode terminal connected to the thermocouple wire on one open end side of a thermocouple outer tube made of a paper tube having both ends opened. A thermocouple plug having a lead wire and an electrode terminal contact tangent to the lead wire is inserted into the other opening end side of the thermocouple outer tube, and the electrode terminal of the thermocouple chip and the thermocouple plug are inserted inside the thermocouple outer tube. In the thermocouple in which the electrode terminal contact is electrically connected, the outer peripheral surface of the thermocouple outer tube covers the connection point between the electrode terminal of the thermocouple chip and the electrode terminal contact of the thermocouple plug, and one of the paper tubes The ceramic fiber sheet is wound so as to protrude from the open end of the thermocouple wire so as to surround the proximal end portion of the thermocouple wire to form a heat-resistant layer, and a protruding edge that is bent inwardly is provided at the tip of the heat-resistant layer . Heat is applied to the part surrounded by the heat-resistant layer protruding from the open end. The constitution filled with short fibers of ceramics so as to reach the Ikatsu the protruding edge covering the front end face of the to-chip.
[0007]
By covering the periphery of the thermocouple outer tube made of paper tube with the heat-resistant layer of the ceramic fiber sheet and the ceramic short fiber in this way, the thermocouple outer tube is protected from heat to prevent burning, and the thermocouple chip The connection point between the electrode terminal and the electrode terminal contact of the thermocouple plug is covered to eliminate measurement errors.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a thermocouple according to the present invention will be described below with reference to the drawings. FIG. 1 is an external perspective view of a thermocouple, and FIG. 2 is a longitudinal sectional view thereof. The thermocouple A is mainly composed of a thermocouple outer tube 1 having both ends opened, a thermocouple chip 2, and a thermocouple plug 3. Among them, the thermocouple outer tube 1 is formed of a paper tube. A ceramic sheet 4 is thinly wound around the outer peripheral surface of the thermocouple outer tube 1.
[0009]
The thermocouple chip 2 accommodates a thermocouple wire 5 in a U-shaped tube 6 such as a quartz tube, and this U-shaped tube 6 is held by a thermocouple chip outer tube 8 via a heat-resistant insulating material 7. Most of 6 protrudes downward from the heat-resistant insulating material 7. Further, both ends of the thermocouple wire 5 are fixed to the thermocouple lead materials 9, 9 by spot welding. Electrode terminals 10 and 10 are connected to the thermocouple lead materials 9 and 9, both electrode terminals 10 and 10 are held by an electrode terminal holder 11, and the electrode terminal holder 11 is attached to the thermocouple chip outer tube 8. It is fixed. The thermocouple chip 2 is detachably fitted to one open end of the thermocouple outer tube 1.
[0010]
Further, the thermocouple plug 3 holds the electrode terminal contacts 14 and 14 in the plug outer tube 12 via the electric insulating material 13, and the electrode terminal contacts 14 and 14 and the conductive wires 15 and 15 in the electric insulating material 13. A brazed part is formed, and the male thread part 12a formed on the upper end part of the plug outer tube 12 and the female thread part 16a of the nipple 16 are screwed together to fix the nipple 16. The thermocouple plug 3 is detachably fitted to the other opening end of the thermocouple outer tube 1.
[0011]
Then, the thermocouple chip 2 is inserted from the opening end side below the thermocouple outer tube 1, and the thermocouple plug 3 is inserted from the opening end side above the thermocouple outer tube 1. The electrode terminal 10 and the annular electrode terminal contact 14 at the center of the thermocouple plug 3 are electrically connected, and at the same time, the electrode terminal 10 on the eccentric side of the thermocouple chip 2 and the partial annular electrode terminal contact of the thermocouple plug 3 14 to each other.
[0012]
Thus, a heat-resistant layer 17 is formed on the outer peripheral surface of substantially the entire thermocouple outer tube 1. The heat-resistant layer 17 is provided on the opening end side below the thermocouple outer tube 1 by a length that surrounds the base end portion of the U-shaped tube 6 protruding from the heat-resistant insulating material 7, and a protruding edge that bends inward at the distal end. 18 is provided around. The heat-resistant layer 17 is made of a ceramic fiber sheet (Isolite Kogyo Co., Ltd., trade name Kao Wool Wet Felt) made mainly of alumina and silica and impregnated with a colloidal inorganic binder. A plurality of needles 19 are driven and fixed at the end.
Then, a ceramic short fiber (Isolite Industry Co., Ltd.) mainly composed of alumina and silica so as to cover the tip surface of the thermocouple chip 2 in a portion surrounded by the heat-resistant layer 17 protruding from the open end under the thermocouple outer tube 1. ) Trade name Kao wool 1400 bulk) 20 is filled at a density of 0.2-0.3 g / cm ³ . Further, an adhesive 21 is applied to the other end of the heat-resistant layer 17 between the thermocouple outer tube 1 and the heat-resistant layer 17 in a build-up shape.
[0013]
When the heat-resistant layer 17 is dried, the heat-resistant layer 17 becomes a lightweight and elastic heat insulating material having a hardened surface. Moreover, since the ceramic short fiber 20 is filled in a portion surrounded by the heat-resistant layer 17 on the opening end side under the thermocouple outer tube 1, even if the thermocouple A is immersed in the molten metal as it is, the heat-resistant layer 17 or Molten metal does not enter between the heat-resistant layer 17 and the short fibers 20, thereby protecting the thermocouple outer tube 1 without burning. In particular, since the lower end of the heat-resistant layer 17 is formed with a protruding edge 18 that protrudes inwardly, the sealing performance is excellent. Further, the connection point between the electrode terminals 10, 10 of the thermocouple chip 2 and the electrode terminal contacts 14, 14 of the thermocouple plug 3 is completely surrounded by the heat-resistant layer 17.
[0014]
In this way, the heat-resistant layer 17 is deposited on the outer peripheral surface of the thermocouple outer tube 1 and the space portion surrounded by the heat-resistant layer 17 protruding from the lower end of the thermocouple outer tube 1 is filled with the short fibers 20 of ceramic fibers. When the thermocouple A of the present invention is used to measure the temperature of the molten metal, when immersed in the molten metal from the tip, the thermocouple outer tube 1 made of a paper tube is less likely to burn and burn out. The thermocouple A can be used several times, and even if the immersion depth is deep, the heat conduction is deteriorated by the heat-resistant layer 17 and the heat-resistant short fibers 20, and the depth at which the thermocouple A can be immersed. Even if there are variations in measurement, no measurement error occurs.
[0015]
【The invention's effect】
As described above, the thermocouple according to the present invention covers almost the entire outer peripheral surface of the thermocouple outer tube made of paper tube and one open end of the thermocouple outer tube with a highly heat-resistant ceramic fiber sheet or short fiber. As a result, the paper tube, which is the outer thermocouple tube, is not easily burned out, so that the thermocouple can be used several times, and the total cost can be reduced accordingly. In addition, since the connection point between the electrode terminal and the electrode terminal contact is covered with a heat-resistant layer, the allowable range of shallowness is widened when immersed in molten metal, so that no skill is required and no measurement error occurs. Has an effect.
[Brief description of the drawings]
FIG. 1 is a perspective view of a thermocouple according to the present invention.
FIG. 2 is a longitudinal sectional view of FIG.
3 is a cross-sectional view taken along line XX in FIG.
FIG. 4 is a cross-sectional view of a conventional thermocouple.
[Explanation of symbols]
A Thermocouple 1 Thermocouple outer tube 2 Thermocouple chip 5 Thermocouple wire 10, 10 Electrode terminal 14, 14 Electrode terminal contact 15, 15 Conductor 17 Heat-resistant layer
18 Protruding edge 20 Ceramic fiber short fiber

Claims (1)

Both ends fitted with a thermocouple chip having an electrode terminal connected to the thermocouple wire and thermocouple wires to one open end side of the thermoelectric external tube made from paper tube having an open, other opening of the thermoelectric external tube fitted with thermocouple plug with the electrode terminal contacts which are conductive wires and conductor lines and tangential to the end side, the electrode terminals of the thermocouple tip within said thermoelectric external tube and said electrode terminal contacts of the thermocouple plug In a thermocouple electrically connected,
The outer peripheral surface of the thermoelectric external tube, the electrode terminals and covers the connection point between the electrode terminal contact of the thermocouple plug, and the thermocouple wires to protrude from one opening end of the paper tube of the thermocouple tip in the wound a ceramic fiber sheet so as to surround the base end portion to form a heat resistant layer, projecting edge flexing inward at the distal end of the heat-resistant layer peripheral to set, the heat-resistant layer that protrudes from the open end of the one thermocouple, characterized in that filled with short fibers of ceramics so as to reach the Ikatsu the protruding edge portion to be enclosed covering the front end face of the thermocouple tip.

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