JPH041673Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] This invention relates to a moisture-proof structure for heater terminals.
More specifically, the present invention relates to a moisture-proof structure for a heater terminal portion that is sealed and protected within a terminal box.

[Conventional technology]

Since heaters are generally used at high temperatures, heat-resistant ceramics such as magnesia and alumina are used as insulating materials for heaters. These insulating materials have the property of absorbing moisture in the air at room temperature or low temperature, which reduces the electrical insulation performance of the heater. Sealing treatments have been used to prevent moisture, such as filling with silicone compounds, epoxy resins, or glass.

[Problem that the invention attempts to solve]

By the way, in the manufacture of heaters, after filling with insulating material such as magnesia or alumina, a compression process such as pressing, rolling, and forging is performed, but it is impossible to completely eliminate air inside the heater. When the heater is used at high temperatures, the internal air expands thermally and is discharged by the ends. Even if the sealing treatment described above is performed, a portion of the sealing member is destroyed due to an increase in internal pressure due to thermal expansion of internal air.

Therefore, the internal air repeatedly breathes as the heater heats and cools, and the heater absorbs moisture due to the humidity of the external air, which still causes problems such as poor insulation, which affects the performance of the heater, and does not last long. This was extremely undesirable from the viewpoint of use.

Therefore, the purpose of this invention is to provide a moisture-proof structure for the heater terminal part that can avoid the moisture absorption state that causes the insulation of the heater to deteriorate, and that can maintain good performance and quality even during long-term use. .

[Means for solving problems]

In order to address the above-mentioned problems, this invention aims to reduce the humidity inside the terminal box, taking into account the current limitations of moisture-proofing measures for the heater itself.

In other words, it suppresses the humidity in the so-called closed room or compartmentalized space inside the terminal box, where outside air can enter and exit the heater, to the extent that insulation does not deteriorate, and it communicates with the inside of the terminal box. Insert the perforated case containing a desiccant such as silica gel into the fixing bolt fixedly fixed and erected on the mounting part toward the inside of the box in the external storage part, and screw the nut onto the protruding end of the fixing bolt to remove the perforated case. It has a structure in which the case is removably attached.

[Effect]

With the structure described above, by periodically replacing the desiccant, it is possible to constantly maintain the humidity of the outside air that can go in and out of the heater to a level that does not cause insulation deterioration. It is possible to permanently prevent insulation deterioration due to this effect and, ultimately, deterioration of heater performance and quality due to insulation deterioration. Also,
The perforated case can be easily removed when replacing the desiccant, and maintenance work is also convenient.

〔Example〕

Fig. 1 shows an embodiment of the moisture-proof structure of the heater terminal section according to this invention. A main body part 1 that holds the part HT on the bottom surface, and a lid fixed to a flange 2 connected to the upper end of this main body part 1 with bolts 4 to seal the opening of the main body part 1 through a gasket 3. It consists of a body 5. Reference numeral 6 denotes a perforated case containing a desiccant agent 7, which is the essential part of this invention, and is made of a punched steel plate with one end open, and is inserted through a fixing bolt 8 fixed and erected on the back surface of the lid body 5. and fix it with nuts 9. That is, in this example, the mounting portion is the lid of the terminal box.

Therefore, in order to replace the desiccant 7, the bolt 4
After removing the lid 5 along with the perforated case 6, the nut 9 may be removed to separate the perforated case 6 from the lid 5.

FIG. 2 shows another embodiment, which is a preferred example where the terminal box is enlarged. In addition, in the figure, the same parts as in the above embodiment are indicated by the same reference numerals.
Reference numeral 5' denotes a lid body having a through hole 5'a in the center, and a perforated case 6' formed of a punched steel plate with one end open as in the previous embodiment, is attached to the back side of the mounting plate 11 to which the handle 10 is fixed. The mounting plate 11 is inserted through a fixing bolt 8' which is firmly fixed upright, and is fixed with a nut 9' via a washer 12, and the mounting plate 11 is fixed with a bolt 13 in a state where the through hole 5'a of the lid body 5' is closed. ing. That is, in this example, the mounting portion is a mounting plate that is removably fixed by closing the through hole of the lid.

Therefore, in order to replace the desiccant 7, it is not necessary to remove the lid 5' as in the previous embodiment, but after removing the mounting plate 11 to which the handle 10 is fixed, removing the bolts 13 and removing the perforated case 6'. , the nut 9' and the washer 13 can be removed to separate the perforated case 6' from the mounting plate 11. Therefore, even if the terminal box becomes larger and the lid becomes heavier, the desiccant 7 can be easily replaced.

FIG. 3 shows still another embodiment, in which 5"
is a lid body having a screw hole 5''a in the center, 14 is a plug screwed into this screw hole 5''a, and a perforated case 6'' containing a desiccant 7 is fixed and erected on the plug 14. Insert the fixing bolt 8″ and attach the cap 15.
It is fixed with a nut 9'' through the hole.To replace the desiccant 7, turn the plug 14 and remove the perforated case 6''.
After removing the entire cover body 5'', the nut 9'' and cap 15 are removed to separate the perforated case 6'' from the plug 14. That is, in this example,
The mounting part is a plug that screws into the screw hole of the lid.

In the above embodiment, the perforated case containing the desiccant is located inside the terminal box and is removably installed, but it is also removably installed in an external storage section that communicates with the inside of the terminal box. Also good.

FIG. 4 shows an example of the lid body 5.
An example in which a storage part 16 with a flange communicating with the interior is provided, and a perforated case 6' similar to that shown in FIG. 2 is removably inserted into this storage part 16,
Two types are shown at the same time: a flanged storage section 16 communicating with the inside through an opening 17 on the side of the terminal box, and a similar perforated case 6' removably attached to this storage section. .

Furthermore, FIGS. 5a and 5b show another example of a flanged housing 19 that communicates with the inside through an opening 18 on the side surface of the terminal box. In the flanged storage part 19, which has openings 18 each having a size of 1/6 of the size of b
An example is shown in which a perforated case 6 having a shape as shown in the figure and having a through hole 20 formed only on the surface on the opening 18 side is removably inserted. 11' is a mounting plate with a handle 10', 8 is a fixing bolt 9 is a nut, and in this example, the mounting plate is a mounting portion of the perforated case.

Although there are differences depending on the heater's insulation material and sealing method, as a result of the experiment, the humidity of the outside air is 40%.
% or less, the insulation of the heater does not deteriorate, and it was also confirmed that by adopting the moisture-proof structure of the present invention, it is possible to easily suppress and maintain the humidity inside the terminal box at 40% or less. .

Of course, the amount of desiccant is appropriately determined in relation to the volume inside the terminal box and the period of use.

[Effects of the invention] As described in detail above, the moisture-proof structure of the heater terminal section according to this invention is such that the moisture-proof structure of the heater terminal section in the inside of the terminal box that protects the heater terminal section in a sealed state or in the external storage section that communicates with the inside of the terminal box is directed toward the inside of the box. A perforated case filled with a desiccant such as silica gel is inserted into the fixing bolt fixedly fixed to the mounting part, and the nut is screwed onto the protruding end of the fixing bolt to removably attach it. By replacing the desiccant at the same time, the humidity inside the terminal box can be kept low at all times, and even if air enters or exits the heater, insulation will not deteriorate due to the hygroscopicity of the heater's insulation material. It has been possible to provide a moisture-proof structure for a heater terminal portion that is highly useful and can maintain good performance and quality of the heater during long-term use. Furthermore, since the perforated case containing the desiccant can be easily removed and installed, it also has the advantage of easy maintenance work.

[Brief explanation of drawings]

Fig. 1 is a schematic vertical sectional view showing an embodiment of the moisture-proof structure of the heater terminal portion according to this invention, and Fig. 2a
2 is a schematic vertical sectional view showing a type in which a perforated case is fixed to a removable mounting plate at approximately the center of the lid body, and FIG. 2b is a perspective view showing the same mounting plate and the perforated case.
FIG. 3 is a partial vertical sectional view showing an example of a screw-in type using a plug, and FIGS. 4 and 5 a and b are
FIG. 7 is a partial vertical cross-sectional view showing an example in which a perforated case is attached to an external storage portion that communicates with the inside of a terminal box. HT...Heater terminal section, TB...Terminal box,
5, 5', 5'', 5...Lid body, 5''a...Screw hole,
5'a... Through hole, 6, 6', 6'', 6... Perforated case, 7... Desiccant, 10, 10'... Handle,
11, 11'...Mounting plate, 14...Plug.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In the inside of the terminal box or in the external storage part communicating with the inside, a desiccant such as silica gel is put into the fixing bolt fixedly erected at the mounting part toward the inside of the box. A moisture-proof structure for the heater terminal section, in which the perforated case is removably attached by inserting the perforated case and screwing a nut onto the protruding end of the fixing bolt. (2) A moisture-proof structure for a heater terminal portion according to claim 1, wherein the mounting portion is a lid of a terminal box, and the fixing bolt is fixed and erected on the back surface of the lid. (3) Claim 1 of the utility model registration claim wherein the lid of the terminal box has a through hole approximately in the center, and the mounting portion is a mounting plate that is removably fixed by closing the through hole. Moisture-proof structure for heater terminals. (4) A moisture-proof structure for a heater terminal portion according to claim 1, wherein the lid of the terminal box has a screw hole approximately in the center, and the mounting portion is a plug screwed into the screw hole.