KR102049843B1 - Temperature sensor unit - Google Patents

Abstract

The present invention provides a temperature sensor unit capable of preventing precise temperature sensing and preventing electrical function abnormality due to condensation when using a temperature sensor. According to the present invention, the temperature sensor unit comprises: a temperature measuring element connected to a plurality of conducting wires; a protective tube provided with an inner space for accommodating the temperature measuring element; a leakage preventing cap having a fastening unit coupled to an opening of the protective tube, wherein the conducting wires connected to the temperature measuring element are drawn out to the outside, and the inner space of the protective tube is sealed; and an insulating fluid filled in the inner space of the protective tube to maintain the temperature measuring element in an insulated state in the inner space of the protective tube.

Description

Temperature sensor unit {TEMPERATURE SENSOR UNIT}

The present invention relates to a temperature sensor unit, and more particularly, to a temperature sensor unit having a watertight waterproof function applied to devices of various fields.

Generally, a temperature sensor is equipped with the temperature detection means, such as a thermocouple and a resistance thermometer, inside the resin sealing pipe (protective pipe). These temperature sensors are used in various industrial facilities because they can be measured with a relatively accurate temperature over a wide temperature range because of their convenience and economy.

On the other hand, as a conventional temperature sensor, for example, a sealing temperature sensor made of resin is disclosed, which is difficult to secure excellent response because of low mechanical strength and relatively low thermal conductivity. Accordingly, there is disclosed a temperature sensor having a temperature detecting means such as a thermocouple or a resistance thermometer using a metal protective tube having excellent mechanical strength and thermal conductivity instead of a resin sealed pipe.

1 is a cross-sectional view showing a configuration of a temperature sensor provided with a conventional metal protective tube, wherein the conventional temperature sensor is composed of a front end 5, a grip 6, and a distal end 7. A sheath 1 (protective tube) is provided at the tip portion 5, and a thermocouple 4 composed of the temperature measuring element 2 and the conducting wires 3a and 3b is provided inside the sheath 1. Here, the sheath 1 is made of stainless material. In addition, the thermocouple 4 is provided with conducting wires 3a and 3b electrically connected to the temperature measuring element 2 and the temperature measuring element 2. On the other hand, a cylindrical grip 6 is provided at the other end of the sheath 1. Lead wires 7a and 7b extend inside the distal end 7 connected to one end of the cylindrical grip 6.

A temperature sensor provided with a conventional metal protective tube having such a configuration has an advantage of ensuring mechanical strength and securing corrosion resistance or fire resistance.

However, in the conventional temperature sensor, when a temperature difference between the internal and external air occurs, condensation occurs inside the sheath 1 made of a metal or a non-metal material, and thus, it is difficult to accurately sense temperature. -circuit) is raised. That is, in a high temperature and high humidity environment, a short circuit occurs on a circuit of a PCB due to an ion difference due to a potential difference (a so called ion migration phenomenon).

On the other hand, the sheath 1 made of metal has different expansion coefficients from the lead wires 7a and 7b or the insulator (especially in the case of using a solid epoxy), so that the boundary line between them due to different flat window coefficients during sudden rise or fall of external temperature There is a problem that separation occurs in (crack).

In addition, when a solid epoxy or the like is used as an insulator, small pores (aka voids) are generated during curing of the epoxy, resulting in a decrease in insulation performance, which leads to product defects.

<Previous Document 1> Republic of Korea Patent Publication No. 2011-0002028 (Published: January 06, 2011)

The present invention has been made to solve the above problems, the temperature sensor unit that can prevent precise temperature sensing and electrical abnormalities (short due to ion migration phenomenon) caused by the dew condensation when using the temperature sensor The purpose is to provide.

According to an embodiment of the present invention for achieving the above object, the RTD is connected to a plurality of conductors; A protective tube provided with an inner space for accommodating the temperature measuring element; a leakage preventing cap having a fastening part coupled to an opening of the protective tube, the conductive wire connected to the temperature measuring element, drawn out to seal the inner space of the protective tube; And an insulating fluid filled in the inner space of the protective tube and maintaining the temperature measuring element in an insulated state in the inner space of the protective tube.

The leakage preventing cap may be formed in the thread portion to be detachably installed in the opening of the protective tube.

The leakage preventing cap may include a packing mounting groove formed on at least one surface from which the lead wire is drawn out, and the packing mounting groove may be equipped with a packing member for sealing around the lead area of the lead wire.

The insulating fluid may be at least one of silicone oil, alcohol, and thermal grease.

According to the present invention, by filling the inside of the protective tube housing the temperature measuring element with an insulating fluid to prevent the generation of pores (void) in the application of the conventional solid insulator, and to prevent the occurrence of the temperature difference between the inside and outside the condensation on the inner surface of the protective tube It can be prevented from occurring. In other words, by filling the inside of the protective tube with an insulating fluid to prevent condensation due to the temperature difference between the internal and external air, it is possible to prevent the short circuit or deterioration of the temperature measuring element.

1 is a cross-sectional view showing the configuration of a conventional temperature sensor provided with a metal protective tube;
2 is a block diagram of a temperature sensor unit according to an embodiment of the present invention, and
3 is a process flowchart showing a manufacturing process of a temperature sensor unit according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings will be described in more detail the present invention. Prior to this, terms or words used in the present specification and claims should not be construed as being limited to the ordinary or dictionary meanings, and the inventors should properly explain the concept of terms in order to best explain their own inventions. Based on the principle that it can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention. In addition, unless there is another definition in the technical terms and scientific terms used, it has the meaning that is commonly understood by those of ordinary skill in the art. In the following description and the accompanying drawings, descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted. The accompanying drawings are provided by way of example so as to fully convey the spirit of the invention to those skilled in the art. Accordingly, the present invention is not limited to the drawings presented below and may be embodied in other forms. Also, like reference numerals denote like elements throughout the specification. It should be noted that the same elements in the figures are represented by the same numerals wherever possible.

2 is a block diagram of a temperature sensor unit according to an embodiment of the present invention. 2, the present invention includes a temperature measuring element 10, a protective tube 20, a leakage preventing cap 40, and an insulating fluid 70.

In the above-described configuration, the temperature measuring element 10 is a sensor element for measuring temperature, and the conductive part 80 formed of a plurality of conductive wires 80a and 80b in one direction is electrically connected.

The temperature measuring element 10 is positioned in the inner space of the protective tube 20. At this time, the protective tube 20 may be made of a variety of materials, but preferably made of stainless steel or metal or non-metal having good thermal conductivity to satisfy the corrosion resistance and durability. In addition, a thread is formed on the outside of the open one side area of the inner space of the protective tube 20. This thread serves as a fastening portion 50 provided for screwing the leakage preventing cap 40.

Leakage prevention cap 40 is made of a synthetic resin material by injection molding and made of a solid portion 30 filled in the inside, a portion of the outer circumferential surface is formed with a screw thread is detachably installed in the opening of the protective plate 20. That is, the leakage preventing cap 40 is a component that seals the opening side of the protective plate 20. Meanwhile, a first packing mounting groove 31 in which the first packing member 60a is mounted is formed on the bottom surface 33 of the leakage preventing cap 40 to seal the peripheral area from which the conductive part 80 is drawn out.

In addition, the upper surface 34 of the leakage preventing cap 40 is formed to have a convex curved surface, and the lead portion 80 is drawn out at the vertex region of the upper surface, and the upper surface for sealing the lead area around the lead region 80 ( The second packing mounting groove 32 is formed at the center side of the 34, and the second packing member 60b is mounted at the second packing mounting groove 32.

On the other hand, the inner space of the protective tube 20 is filled with the insulating fluid 70 is configured to lock the temperature measuring element 10 in the middle of the insulating fluid (70). Therefore, the inner space of the protective tube 20 is filled with the insulating fluid 70 so that the empty space does not occur inside. Meanwhile, the first packing member 60a and the second packing member 60b of the leakage preventing cap 40 prevent the insulating fluid 70 from leaking around the lead area of the lead portion 80 of the temperature measuring element 10. It plays a role.

As described above, the present invention can prevent the condensation from occurring in this space by buffering the inner space of the protective tube 20 with the insulating fluid 70 so as not to generate a space (hollow area) inside the protective tube 20. At this time, the insulating fluid 70 may be at least one of silicon oil, alcohol, thermal grease (thermal grease).

Hereinafter, the manufacturing method of the temperature sensor unit of the present invention will be described. 3 is a process flowchart showing a manufacturing process of a temperature sensor unit according to an embodiment of the present invention.

Temperature sensor unit of the present invention is a temperature measuring element coating step (S 10)-protective tube processing step (S 20)-leak prevention cap injection molding step (S30)-temperature measurement element mounting step (S 40)-leak prevention secondary charging step ( S 50)-insulating fluid filling step (S60)-leak prevention cap assembly step (S 70)-appearance washing step (S 80)-inspection step (S90) is made in the process sequence.

Specifically, first, the RTD 10 is coated. At this time, the coating solution may be epoxy, silicone, oil repellent (for example, mixed synthetic resin).

Next, the tubular protective tube 20 is formed to have an inner space. In other words, the inner space of the protective tube 20 is provided in a form in which one side is sealed and the other side is opened to accommodate the insulating fluid 70 and the temperature measuring element 10. In addition, the upper end of the protective tube 20 is formed with a fastening portion 50 is formed in the threaded section. Accordingly, the leakage preventing cap 40 is coupled through the fastening part 50 of the protective tube 20 to seal the inner space of the protective tube 20.

Meanwhile, the leakage preventing cap 40 may form a synthetic resin material through injection molding. At this time, the bottom surface 33 of the wild boil disaster cap 40 is located inside the protective tube 20 and accommodates the insulating fluid 70 in a sealed state in the protective tube 20. That is, the leakage preventing cap 40 is screwed to the protective tube 20 through the fastening part 50 to seal the insulating fluid 70 inside the protective tube 20 to prevent leakage to the outside.

At this time, the leakage preventing cap 40 is provided in the form of a solid cap filled with a synthetic resin material inside, the conductive portion 80 is penetrated in the horizontal direction based on Figure 2, the temperature measuring element at the tip of the conductive portion 80 10 is connected. At this time, in the center of the upper surface 34 and the lower surface 33 of the leakage preventing cap 40, packing mounting grooves 31 and 32 of a predetermined depth are formed, respectively.

Specifically, the first packing member 60a is mounted on the first packing mounting groove 31 formed on the bottom surface 33 of the leakage preventing cap 40, and the first packing member 60a is formed on the upper surface 34 of the leakage preventing cap 40. The second packing member 60b is mounted to the two packing mounting grooves 32. Here, the first packing member 60a and the second packing member 60b serve to seal the periphery of the conductive portion 80 penetrating the leakage preventing cap 40.

That is, the leakage preventing cap 40 is provided with a plurality of packing mounting grooves 31 and 32 and packing members 60a and 60b mounted thereto, so that the insulating fluid 70 accommodated in the liquid state inside the protection tube 20 is leaked. Prevents the outflow along the gap around the conductive portion 80 penetrating the prevention cap 40 to the outside.

Here, the packing members 60a and 60b are provided in the form of inserting a conventional packing member into the packing mounting grooves 31 and 32, or in another form, by installing the leakage preventing cap 40 in the protective tube 20 to form an insulating fluid ( In the sealed state 70, the packing material for preventing leakage may be filled in the packing mounting grooves 31 and 32.

Specifically, in the state in which the leakage preventing cap 40 is mounted on the protection tube 20, the leakage preventing cap 40 has a diameter smaller than the through hole of the conductive part 80 in the leakage preventing cap 40. The packing may be formed by filling in the first packing mounting groove 31 or the second packing mounting groove 32 by filling a filler such as liquid silicone to cure the filling material.

On the other hand, the present invention has a focus on filling the inside of the protective tube 20 with the insulating fluid 70 in a state in which the temperature measuring element 10 is mounted inside the protective tube 20. That is, the insulating fluid 70 employs a fluid that does not harden and is not mixed with water, such as silicone oil, alcohol, and thermal grease, thereby preventing space from being formed inside the protective tube 20. Of course, by preventing the mixing with water, it is possible to prevent the occurrence of condensation around the temperature measuring element 10 installed inside the protective tube (20).

In the last process, the appearance of the device can be washed in the state in which the insulating fluid 70 is filled in the protection tube 20, and the leakage test and the performance test can be performed.

At this time, in order to check the leakage of the insulating fluid 70, the temperature sensor unit may be immersed in the test liquid after the alcohol ultrasonic cleaning process to check the leakage. Alternatively, leakage of the insulating fluid 70 may be tested using an airtight tester. After that, the inspection is finished through the electrical performance test of the RTD 10.

Although the present invention has been illustrated and described with respect to specific embodiments thereof, the present invention is not limited to the above-described embodiments, and a person skilled in the art to which the present invention pertains has the present invention described in the following claims. Various changes may be made without departing from the spirit of the technical idea of the invention.

10: RTD
20: sheriff
30: solid part
40: Leakage prevention cap
50: fastening part
60a: first packing member
60b: second packing member
70: insulating fluid
80: lead portion
80a, 80b: lead wire

Claims (5)

An RTD connected with a plurality of conductors;
A protective tube provided with an inner space for accommodating the temperature measuring element;
A leakage preventing cap having a fastening part coupled to the opening of the protective tube, and the conductive wire connected to the temperature measuring element withdrawn to the outside and sealing a part of the inner space of the protective tube; And
An insulating fluid filled in the inner space of the protective tube to keep the temperature measuring element insulated from the inner space of the protective tube,
The leakage preventing cap has a packing mounting groove formed on at least one surface of the lead wire is drawn out, the packing mounting groove is equipped with a packing member for sealing around the lead area of the lead wire,
The leakage preventing cap, the temperature sensor unit, characterized in that at least one fine hole for supplying a filler from the outside to form the packing member. The method of claim 1,
The leakage preventing cap,
And a screwing unit detachably coupled to the opening of the protective tube. The method of claim 1,
The insulating fluid,
At least one of a silicone oil, an alcohol, and a thermal grease.

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