KR100767792B1 - Non-ground type sheath thermocouple and method of manufacturing thereof - Google Patents

Abstract

A non-ground type sheath thermocouple and a manufacturing method thereof are provided to increase productivity and reliability and to improve temperature measuring performance in various fields. A manufacturing method of a non-ground type sheath thermocouple includes a step of cutting the sheath thermocouple installed inside a sheath into certain length and processing and flattening one end portion thereof(S10); a step of processing a hole of predetermined depth at an inside of the sheath thermocouple from the flat end portion(S20); and a step of gathering and welding both rear ends of a wire of the thermocouple of the inside for the sheath thermocouple exposed by the hole-processing operation(S30). The outer diameter of the sheath is in the range of 0.25 to 0.5mm, and the hole is processed from a front end portion of the sheath thermocouple to the depth of 0.5 to 1mm.

Description

Non-ground type sheath thermocouple and method for manufacturing the same

1 is a cross-sectional view of the sheath thermocouple according to an embodiment of the present invention.

Figure 2 is a schematic flowchart of a method for manufacturing a sheath thermocouple according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

10: ungrounded sheath thermocouple 11, 12: thermocouple element wire

13: insulation material 14: sheath

15: Plug 16: RTD

17: hole 18: epoxy molding

20: Instrument

The present invention relates to a sheath thermocouple and a method of manufacturing the same, and more particularly to a non-grounded sheath thermocouple having high productivity and reliability and excellent response.

A thermocouple is a device that measures the temperature by joining two different metal wires together. More specifically, a thermocouple electrically connects two ends of two types of metal conductors and gives a temperature difference between the two types of conductors to generate a Seebeck effect through which a current flows in the circuit, and maintains the temperature at one end (reference contact point) at a constant temperature. It is a device that can measure the temperature of the other end (temperature contact point) by measuring the value of the thermoelectric power.

The thermocouple of this principle is relatively simple in structure and can measure a wide range of temperature from cryogenic -200 ° C to very high temperature of 3000 ° C, which is widely used for various industrial temperature measurement and medical temperature measurement.

The thermocouple is classified into a general thermocouple and a sheath thermocouple according to the type of protection of the thermocouple element in which the temperature-contacting point is formed. General thermocouples are composed of a combination of separately manufactured protective tubes, thermocouple wires, insulated tubes, and terminal boxes. It is used more than general thermocouple because it has characteristics such as.

The sheath thermocouple may be divided into a grounded type or a non-grounded type depending on whether the thermocouple element is grounded to a metal protective tube (hereinafter, referred to as 'sheath'). The grounding type is a form in which a thermocouple element is directly welded to the tip of a sheath to form a temperature-contacting contact. It is fast in response and suitable for measuring temperature under high temperature and high pressure. The non-grounding type is a type that completely insulates the thermocouple wires from the sheath and forms a temperature-contacting contact. It has little change in thermoelectric power over time and can withstand long-term use. It can also be used safely in hazardous locations without being affected by noise voltage. Furthermore, if the insulation resistance meter is installed on the pair of thermocouple wires, the insulation resistance of the insulation material can be easily measured. The present invention relates to an ungrounded sheath thermocouple.

By the way, the non-grounded sheath thermocouple having various advantages as described above is very difficult and complicated to weld the fine thermocouple element inside the sheath to make the temperature-contacting point, and thus, most of the expensive imported products are imported from foreign countries. In particular, the outer diameter of the sheath tends to be minimized to 0.5 pi (?) To 0.25 pi (?), So that more and more advanced technology is required. In addition, the poor contact of the temperature contact point of the thermocouple element is found after the completion of the product has caused a problem that the productivity of the sheath thermocouple and the reliability of the product is lowered.

The present invention has been made to solve the problems of the prior art, an object of the present invention to provide a non-grounded sheath thermocouple with high productivity and high reliability for the product.

Another object of the present invention is to provide a method of manufacturing a non-grounding sheath thermocouple having high productivity and reliability of a product.

In order to achieve the above object, the non-grounded sheath thermocouple according to the present invention is formed by welding a pair of temperature measuring thermocouple wires are arranged inside the sheath filled with an insulating material and one end of the thermocouple wires is completely insulated from the sheath. Including a temperature measuring contact, wherein the temperature measuring contact is characterized in that the structure formed by welding in a hole formed to a predetermined depth from the sheath thermocouple tip to the inside of the sheath thermocouple.

The method of manufacturing an ungrounded sheath thermocouple according to the present invention includes a first step of cutting a sheath thermocouple disposed in a sheath filled with an insulating material by a pair of temperature measuring thermocouple wires to a predetermined length and processing one end in a plane; And a second step of forming a hole from the planar end to the inside of the sheath thermocouple at a predetermined depth, and welding both ends of the thermocouple element wires inside the sheath thermocouple exposed by the hole processing to the center of the sheath thermocouple. Characterized in that it comprises a third step.

Preferably the outer diameter of the sheath is 0.5mm ~ 0.25mm, the hole is formed 0.5mm ~ 1mm depth from the tip of the sheath thermocouple.

Preferably, the manufacturing method of the non-grounding sheath thermocouple according to the present invention further includes a fourth step of checking whether there is a welding abnormality by performing a non-contact test after welding, and a fifth step of sealing the cap by welding a stopper to the tip of the sheath thermocouple. It is configured by.

Hereinafter, the specific configuration of the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view of a sheath thermocouple according to a preferred embodiment of the present invention, Figure 2 is a schematic flowchart of a method for manufacturing a sheath thermocouple according to a preferred embodiment of the present invention.

Referring to FIG. 1, a non-grounded sheath thermocouple 10 according to a preferred embodiment of the present invention has a pair of temperature measuring thermocouple wires 11 and 12 filled with an insulating material 13 inside the sheath 14. The thermocouple element wire (11, 12) is formed of a temperature measuring contact 16 formed by welding one end (first end) of the sheath 14 is completely insulated from the sheath 14, the temperature measuring contact 16 is a sheath thermocouple It is a structure formed by welding in the hole 17 formed in the sheath thermocouple to a predetermined depth from the tip portion.

Referring to FIG. 2, in the method of manufacturing a non-grounding sheath thermocouple according to the present invention, a pair of temperature measuring thermocouple wires are cut into a sheath thermocouple disposed inside a sheath filled with an insulating material to a predetermined length, and one end (first A first step S10 of processing the end) into a plane, a second step S20 of forming a hole 17 into the sheath thermocouple from the planar processed end (the first end), and the A third step (S30) of collecting both ends of the thermocouple element inside the sheath thermocouple exposed by hole processing in the center of the sheath thermocouple and welding, and the fourth step (S40) to check the presence of welding abnormality by performing a non-contact test after the welding. And a fifth step (S50) of sealing the stopper by welding a stopper to the tip of the sheath thermocouple.

Hereinafter, each step will be described in more detail with reference to FIGS. 1 and 2. The sheath thermocouple may be made of stainless steel, inconel, hapronickel, SUS 304, SUS 316, or the like. In addition, there is no particular limitation on the outer diameter of the sheath thermocouple, but in the present invention, a fine sheath thermocouple of 0.5 mm to 0.25 mm is also applicable. In the following, the embodiment will be described based on the sheath thermocouple having an outer diameter of 0.5 mm or 0.25 mm. The thermocouple element wires 11 and 12 are not particularly limited in material and diameter, but when the outer diameter of the sheath 14 is 0.25 mm, the diameter of the thermocouple element wires 11 and 12 may be 0.045 mm. A pair of temperature measuring thermocouple wires 11 and 12 may use a sheath thermocouple 10 in a semi-finished state arranged inside the sheath 14 filled with the insulating material 13.

In the first step S10, the sheath thermocouple 10 is cut to a predetermined length so as to be suitable for an application by using a known wire cutting technique. Next, the cut end (first end) is processed into a plane by using a belt polishing machine or the like. The cut opposite sheath thermocouple end (second end) removes the insulating material 13 and sheath 14 using a wire stripper to expose the thermocouple element ends 11 and 12.

Next, a hole is formed in the sheath thermocouple end (first end) from the cut and planarly processed sheath thermocouple end (inner diameter of about 0.3 mm or 0.18 mm) to form the hole 17 at a predetermined depth using a fine drill. (Step 2 S20). In this way, by welding the hole 17 to secure the inner space of the sheath thermocouple, the welding efficiency can be increased, and thus the reliability of the product can be improved.

Preferably, the depth of the hole 17 is 0.5 mm to 1 mm from the sheath thermocouple end (first end). When the distance D is 0.5 mm or less, the thermocouple wires 11 and 12 are more likely to be grounded with the stopper 15 to be welded later. When the distance D is 1 mm or more, the thermocouple wires 11 and 12 are visually observed. Difficult to check, making welding difficult.

The ends of the pair of thermocouple element wires 11 and 12 are collected at the center of the sheath thermocouple in the processed hole 17. At this time, the magnifier can be used for more precise work. Then, the ends of the thermocouple element wires 11 and 12 collected above are welded to form the temperature-contacting point 16 (third step S30). At this time, the welding may use a laser welding machine or an argon welding machine, and be careful not to contact the sheath.

Next, a non-contact test is performed by connecting a tester to the second end of the sheath thermocouple to confirm that the welding is not performed and short-circuited (fourth step S40). In this case, the tester may use a multimeter, a buzzer tester, or the like. Thus, by performing a non-contact test in the product manufacturing process it is possible to increase the reliability and productivity of the product.

If there is no abnormality after the non-contact test, the stopper 15 is welded to the sheath thermocouple end (first end) to seal the tip (fifth step S50). At this time, the stopper 15 is the same as the material of the sheath 14, the welding can be made by argon welding. After welding the stopper 15, the multimeter and the subwoofer tester are connected to the second end, and the noncontact test is performed again. As described above, the additional non-contact test is performed once more, thereby increasing the reliability of the product.

Next, the insulation resistance tester is connected to the second end of the sheath thermocouple to perform an insulation resistance tester. If the insulation resistance does not meet the standard value (500V 200MΩ or more), put the sheath thermocouple in the drying furnace and dry it to get the predetermined insulation resistance value.

Then, the + and-terminals (wires) are respectively connected to the ends of the thermocouple element wires 11 and 12 protruding from the second end. At this time, the connection may be used a silver bar (silver long furnace) welding, spot welding technology.

The second end of the sheath thermocouple and the terminal (wire) are connected to the sleeve (not shown) and the second end of the sheath thermocouple is pressed by a hydraulic press, and the terminal (wire) side is molded with epoxy 18.

Finally, thermocouple calibration is used to complete the product as a temperature sensor. In the measurement of the thermoelectric power of the sheath thermocouple according to the present invention, a well-known movable coil type or an electromagnetic tube type automatic balancing instrument, a potentiometer, or the like can be used.

The present invention can be applied to therapeutic medical devices. For example, high frequency can be applied to the surface of the sheath to treat various symptoms such as cancer and inflammation, and the temperature can be measured by thermocouple wire inside the sheath thermocouple. At this time, the sheath thermocouple according to the present invention can prevent the temperature rise of the treatment site due to the high reliability of the product and the quick temperature response.

In addition, the present invention can prevent overheating of semiconductor (IC chip, circuit inside) equipment and can be used for performance test (high temperature, low temperature) of semiconductor products.

Conventional products have a large outer diameter and a slow temperature response rate, which do not detect minute fluctuations in temperature and have low reliability and productivity of the product. These problems can be solved by the present invention. In addition, according to the present invention there is an advantage that it is possible to install a temperature sensor device using a sheath thermocouple with high product reliability even in a difficult or small and thin site of the conventional temperature sensor device.

The present invention described above is not limited to the above-described embodiments and drawings, and various substitutions, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be apparent to those who have

As described above, according to the non-grounded sheath thermocouple according to the present invention and a manufacturing method thereof, it is possible to increase the productivity and reliability of the non-grounded sheath thermocouple. Therefore, the present invention is a very useful invention because it can provide a highly reliable sheath thermocouple at the time of temperature measurement in various fields such as high-frequency medical devices, semiconductor manufacturing process.

Claims (7)

delete delete delete In the method of manufacturing a non-grounding sheath thermocouple, A first step of cutting the sheath thermocouple disposed in the sheath filled with the insulating material by a pair of temperature measuring thermocouple wires to a predetermined length and processing one end in a plane; A second step of forming a hole from the planar end to a predetermined depth into the sheath thermocouple; And And a third step of collecting both ends of the thermocouple element wires inside the sheath thermocouple exposed by the hole processing in the center of the sheath thermocouple, and welding the same. The method of claim 4, wherein the outer diameter of the sheath is 0.5mm to 0.25mm. The method of claim 5, wherein the hole is 0.5 mm to 1 mm deep from the tip of the sheath thermocouple. The method according to any one of claims 4 to 6, A fourth step of checking whether there is a welding abnormality by performing a non-contact test after the welding; And And a fifth step of sealing the cap by welding a stopper to the tip of the sheath thermocouple.

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