JPS5847395Y2 - consumable immersion thermocouple - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a consumable immersion thermocouple for measuring the temperature of molten metal.

Conventionally, the temperature of molten metal (hereinafter referred to as molten metal) has generally been measured using a consumable immersion thermocouple (hereinafter referred to as a probe), but temperature measurement using this probe is also a contact measurement. Therefore, it can be measured with high accuracy,
Very useful for temperature control and energy saving.

On the other hand, in recent years, from the viewpoint of resource conservation, it has become common practice to collect the thermocouple wires of probes that are discarded after measurement and to reuse them by remelting and refining them.

FIG. 1 shows a typical example of a conventional probe.

This involves connecting the thermocouple wires 4 and 5 protected by a quartz U-shaped tube 1 to the thermocouple lead wires 6 and 7 inside the housing 3 and solidifying them with heat-resistant cement 2. In the drawing, a female connector is formed by folding the downward extension at a suitable point on the resin connector main body 8, and a cap 9 that surrounds the quartz U-shaped tube 1 is attached to the housing 3, and the molten metal of the housing 3 is A protective tube 10 made of a paper tube or the like is attached to surround the part to be immersed.

The thermocouple wire is made of platinum-based metal wire, and is generally Q, 1
It has a diameter of about mm.

The female connector is connected to a male connector at the tip of a movable holder (not shown).

Conventionally, the thermocouple wires 4 and 5 have been recovered by breaking the quartz U-shaped tube 1 and pulling out the thermocouple wires inside with tweezers, or by breaking the housing 3 with a hammer or the like and then using hardened cement 2. The method used is to crush the thermocouple wire and take out the thermocouple wire, but while the former method is simple, the recovery rate is low because the part buried in the cement 2 cannot be recovered.On the other hand, the latter method Although the recovery rate is close to 100%, it is too time-consuming and not economically viable, so it has only been implemented in a small number of cases to date.

In addition, in Fig. 1, after filling the material made of resin coated sand instead of cement 2,
A method has also been proposed in which the quartz U-shaped tube and the thermocouple wire are stably fixed by heating at a temperature of 0°C for 100 to 200 seconds to melt and bond the resin. Therefore, it is difficult to uniformly melt and fix the resin, and in order to achieve uniformity, it is necessary to raise the heating temperature and extend the heating time, which has the disadvantage of lengthening the assembly time. This creates a cyclic atmosphere, which in the case of platinum-based thermocouple wires leads to deterioration or disconnection of the wires, which is not practically satisfactory.

Furthermore, as shown in FIG. 1, the method filled with heat-resistant cement has the disadvantage that variations in the degree of dryness lead to variations in the insulation between thermocouple wires, resulting in variations in measurement accuracy.

An object of the present invention is to provide a probe that allows thermocouple wires to be collected easily and efficiently, and that does not cause variations in measurement accuracy.

According to the present invention, the first and second tubes are each made of pre-formed resin-coated sand and have two pores therein for passing the thermocouple wire lead-out portion or the thermocouple lead wire connected thereto. The first part of the core made by gluing the parts together
A thermocouple wire protected by a quartz U-shaped tube is connected to the end of the second part, and a connector is formed at the end of the second part. A housing having a metal cap surrounding the quartz U-shaped tube attached to the tip side, and a protective tube made of a paper tube or the like attached to surround the part of the housing to be immersed in the molten metal. A probe is provided comprising:

The invention will now be described with reference to the illustrated embodiments.

Fig. 2 shows a heat-sensitive unit constructed according to the present invention, Fig. 3 shows a heat-sensitive element formed by fitting the heat-sensitive unit of Fig. 2 into a housing, and Fig. 4 shows the heat-sensitive element of Fig. 3 in a protective tube. It is a figure which shows the fitted state.

In FIG. 2, 11a is a first part of a core made of pre-molded resin coated sand and has two pores therein through which the lead-out parts of the thermocouple wires 4 and 5 are passed; 11b;
The core is also made of resin-coated sand which is pre-formed and has two pores inside which pass part of the lead-out portions of the heating element pair wires 4 and 5 and the thermocouple lead wires connected thereto. 2, 12.13 is the connection point between the thermocouple wires 4 and 5 and the thermocouple lead wires 6 and 7, 14 is the hot junction, and 15.
16 indicates an adhesive, 17 a refractory cement, and other reference numbers indicate components corresponding to those shown in FIG.

The first part 11a of the core of the adhesive 15 is connected to the second part 1
1 b, and the adhesive 16 is attached to the second part 11 of the core.
b is integrally glued to the connector body 8, and refractory cement 17 is applied.
The legs of the quartz U-shaped tube 1 are inserted into the pores of the first portion 11a of the core and fixed.

The first part 11a of the core is immersed in the molten metal and shaped by determining the particle size of the silica sand, the amount of resin, and the firing time so that the resin will not completely gasify and lose its bonding strength by the time the core is pulled up after measurement.

On the other hand, the particle size of the second portion 11b of the core does not matter, but it is sufficient that it does not easily deform due to external forces during the assembly process.

In addition, when assembled as shown in Fig. 2, thermal radiation energy from the molten metal during immersion damages the connection points 12 and 13 between the thermocouple wires 4 and 5 and the thermocouple lead wire using the quartz U-shaped tube 1 as a medium. The direct radiation causes the temperature to rise, which reduces measurement accuracy. Therefore, during actual assembly, the first part 11 of the core is designed to prevent direct radiation from such thermal radiation energy.
The pores in the second part 11b of the core are formed at positions different from the pores in the second part 11b of the core, and then bonded.

In this case, it is necessary to determine the dimensions of the thermocouple wires 4 and 5 to be slightly longer, assuming in advance that the pores will be shifted in this way.

In this specification, the unit assembled to the state shown in FIG. 2 is referred to as a heat-sensitive unit for convenience and is designated by reference symbol A.

Figure 3 shows the heat sensitive unit (A) shown in Figure 2 in housing 1.
In order to distinguish it from the state shown in FIG. 2, it is referred to as a heat-sensitive element and designated by the reference number B.

More specifically, the heat-sensitive element B is manufactured by pushing the heat-sensitive unit I/A into the hollow part of the housing 18 from below and using the adhesive 20.
By bonding the housing 18 and the connector body of heat-sensitive unit A, and applying refractory cement 19, molten metal enters through the gap between the housing 18 and the first part of the core of heat-sensitive unit A. It is designed to prevent this.

The metal cap 9 for protecting the quartz U-shaped tube 1 is attached by caulking the extended portion of the edge of the cap 9 to the flange portion 18a of the housing 18.

FIG. 4 shows a state in which the heat-sensitive element B shown in FIG. 3 is press-fitted into the paper tube 21 until the flange portion 18a of the housing 18 comes into pressure contact with the end of the paper tube 21, in other words, the completed probe according to the present invention. shows.

When measuring temperature using the probe described above, the probe is attached to a holder (not shown) that can be moved back and forth toward the molten metal, immersed in the molten metal, and the thermoelectromotive force is measured by a meter (not shown). ) to give a temperature indication, but to explain the state of the probe immediately after it is lifted from the molten metal after measurement is completed, (a) the metal cap 9 has burned through, and (b) the flange portion 18 of the housing 18 has melted. a is red hot, (
c) The resin of the resin-coated sand has melted and gasified to a depth of about 5 mm from the surface of the first part 11a of the core, and a small amount of silica sand has fallen off. (d) The quartz U-shaped tube has become red-hot and silica sand has fallen off. Despite falling off, the refractory cement 19 and the thermocouple wires 4 and 5 prevent the thermocouple from falling off.

In this state, after about one minute has passed after the probe is pulled up, the heat of the housing 18 gradually increases to the first part of the core.
and the second portions 11a and 11b, where the melting and gasification of the resin progresses.

Normally, the measurer's routine task is to remove the used probe from the holder and attach a new probe in preparation for the next temperature measurement. If you hold the finished probe in one hand and move the quartz U-shaped tube a little, most of the silica sand will fall off and the thermocouple wire can be easily removed.

In this way, the probe according to the present invention does not lose its shape during immersion measurements (substantially 3 to 4 seconds) and can easily shorten all of the thermocouple wires once the time for lifting and resetting has elapsed. It can be recovered in time.

In addition to the advantages described above, the probe according to the present invention also has the following advantages.

(1) By using a pre-formed core, it is possible to fire a core that is suitable for the purpose and with little variation, eliminates deterioration of thermocouple wires, and significantly reduces probe assembly time. Can be shortened.

(2) Since the heat-sensitive part is made into a unit, the heat-sensitive part, which is the main part of the probe according to the present invention, has an extremely wide range of applications.

An example of such an application is the one described in Japanese Patent Publication No. 51-47637 which shows a sampler for phase change detection.

(3) As mentioned above, with conventional probes filled with heat-resistant cement, temperature measurement accuracy varies, and to prevent this, a longer drying time is required to increase the degree of dryness, which increases assembly time. On the other hand, in this invention, by adopting resin-coated sand, the variation in accuracy due to the degree of dryness has been eliminated.
It is possible to significantly shorten assembly time.

(4) By shifting the pores of the first part and the pores of the second part of the core and adhering them, it is possible to prevent a decrease in measurement accuracy due to thermal radiation energy of the molten metal, and it is also easy to take out the strands. It is.

As described above, the present invention not only saves resources but also reduces temperature measurement costs, and its practical value is extremely high.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing a typical example of a conventional probe, Fig. 2 is a cross-sectional view showing a heat-sensitive unit constructed according to the present invention, and Fig. 3 is a heat-sensitive element formed by fitting the heat-sensitive unit shown in Fig. 2 into a housing. FIG. 4 is a cross-sectional view showing the thermal unit shown in FIG. 3 fitted into a protective tube. 1: Quartz U-shaped tube, 4.5: Thermocouple wire, 6, 7: Thermocouple node wire, 8: Connector body, 9: Cap, 11a
: first part of the core, 11b: second part of the core, 14
: Hot junction, 15, 16: Adhesive, 17: Fireproof cement, 18: Housing, 19: Fireproof cement, 20: Adhesive, 21: Protective tube.

Claims (3)

[Scope of utility model registration request] (1) Glue together the first and second parts, each of which is made of resin-coated sand and has two pores through which the lead-out part of the thermocouple wire or the thermocouple lead wire connected to it is passed. A thermocouple wire protected by a quartz U-shaped tube is connected to the end of the first part of the core made of
A housing includes a heat-sensitive unit formed by forming a connector at the end of the partial side, and a housing into which the heat-sensitive unit is fitted, and a metal cap surrounding the quartz U-shaped tube is attached to the tip side. 1. A consumable immersion thermocouple, comprising: a protective tube made of a paper tube or the like attached to surround a portion of the housing that is immersed in molten metal. (2) Utility Model Registration Scope of Claims In the thermocouple described in claim 1, the first part of the core is formed by immersing the thermocouple in molten metal and removing the resin from the first part by the time the thermoelectric lamp is pulled up after measurement. The particle size of the silica sand, the amount of resin, and the firing time are determined so that the coated resin is melted and gasified to a depth that at least covers the surface, but not all of it is gasified. A consumable type immersion thermocouple. (3) Utility model registration In the thermocouple described in claim 1, the pores in the first part and the pores in the second part of the core are the thermocouple wire and the thermocouple passed through the quartz U-shaped tube. A consumable immersion thermocouple characterized by being shaped at an offset position to prevent direct radiation of thermal energy to the connection point of the lead wire.