JP3717672B2 - Electrode holder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrode holder that holds an electrode used for liquid level control of a boiler or a tank.
[0002]
[Prior art]
FIG. 4 is a partial cross-sectional view of a conventional electrode holder.
[0003]
The electrode holder 1 includes a connection fitting 3 as a connection body for attachment to a liquid container 2 such as a boiler or a tank, an electrode shaft 4 as an electrode body arranged at the center of the connection fitting 3, It has an insulator 5 made of, for example, a fluororesin, which electrically insulates the electrode shaft 4 and seals a gap between them.
[0004]
In a state where the electrode holder 1 is attached to the metal liquid container 2, an electrode rod 8 for detection is connected to the end of the electrode shaft 4 on the liquid container 2 side by a connection nut 6 and a fastening bolt 7. The tip of the electrode rod 8 is positioned at a desired liquid level to be detected.
[0005]
Then, by detecting a change in the conductive state between the end of the electrode shaft 4 where the wiring 9 outside the liquid container 2 is connected and the liquid container 2, the liquid level in the liquid container 2 It is detected whether or not the tip has been reached.
[0006]
[Problems to be solved by the invention]
In such a conventional electrode holder 1, the electrode shaft 4, the connecting fitting 3, and the insulator 5 are integrally formed by injection molding, and the upper end 3 b of the connecting fitting 3 is caulked to thereby connect the upper end 3 b and the connecting fitting. The insulator 5 is tightened between the ring-shaped annular piece 3a projecting in the middle of the middle 3 and the sealing performance is secured. For this annular piece 3a, the electrode shaft 4 There is a thin portion of the insulator 5 between the two.
[0007]
For this reason, when attaching the electrode rod 8 for detection to the electrode shaft 4, if the connection nut 6 is tightened too much, the insulator 5 integral with the electrode shaft 4 tries to rotate integrally with the connection nut 6, and the insulator 5 There is a drawback that the thin portion may be threaded or cracked, resulting in deterioration of insulation.
[0008]
The present invention has been made in view of the above-described technical problems, and an object thereof is to provide an electrode holder in which insulation is prevented from being deteriorated due to an insulator being broken or cracked. To do.
[0009]
[Means for Solving the Problems]
The present invention is configured as follows in order to achieve the above-described object.
[0010]
That is, the present invention according to claim 1 includes a connecting body for attaching the electrode holder to the container, and an insulator that surrounds the outer periphery of the electrode body and insulates the electrode body from the connecting body. In the electrode holder in which a protruding portion is formed on the inner surface of the connecting body and one end of the connecting body is caulked to clamp an insulator between the one end and the protruding portion, A notch is formed at the end and the other end is caulked to adhere to the insulator.
[0012]
According to a second aspect of the present invention, in the configuration according to the first aspect, a plurality of the notches are formed along a circumferential direction of the tubular connecting body.
[0014]
According to a third aspect of the present invention, in the configuration according to the first or second aspect, the protruding portion formed on the inner peripheral surface of the cylindrical connecting body is bent toward the one end side.
[0015]
According to the first aspect of the present invention, since the notch is formed in the other end of the connecting body and the other end is caulked to be in close contact with the insulator, the electrode rod is connected to the electrode body via the connection nut. In addition, even if a force to rotate the electrode body and the insulator integrated therewith is applied, the other end of the coupling body is in close contact with the insulator, so that the rotation of the insulator is prevented. Become.
[0017]
According to the second aspect of the present invention, since the plurality of notches are provided along the circumferential direction of the cylindrical connecting body, the rotation of the insulator integrated with the electrode body is more reliably prevented. Become.
[0019]
According to the third aspect of the present invention, the insulator between the protruding portion bent to one end side and the one end side to be caulked is tightened to improve the sealing performance.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of an electrode holder according to the present invention will be described with reference to the drawings.
[0021]
(Embodiment 1)
FIG. 1 is a partial cross-sectional view of an electrode holder according to Embodiment 1 of the present invention, and portions corresponding to the conventional example of FIG. 4 are denoted by the same reference numerals.
[0022]
Electrode holder 1 ₁ of this embodiment includes a metal electrode shaft 4 as the electrode body, a cylindrical connecting fitting 3 as a connecting member for mounting the electrode holder 1 ₁ to the liquid container 2, A cylindrical insulator 5 is provided that insulates the electrode shaft 4 and the connection fitting 3 and seals a gap between them.
[0023]
An annular piece 3a as a protruding portion that bends upward (upper end side) and bites into the insulator 5 protrudes from the middle inner surface of the connection fitting 3, and the liquid container 2 has a lower outer periphery. screw portion 3c is formed for attachment, the upper portion has a mounting surface 3d of the larger diameter than the threaded portion 3c, further to its upper, screwed the electrode holder 1 ₁ to the liquid container 2 by means of a tool It has a hexagonal portion 3e. The shape of the inner periphery formed by the annular piece 3a is preferably a polygon such as a triangle, a square, or a hexagon, but may be a circle.
[0024]
An electrode rod 8 suspended in the liquid container 2 is connected to the lower end of the electrode shaft 4 via a connection nut 6 and a fastening bolt 7. The upper end side of the electrode shaft 4 is a terminal portion for performing wiring 9 to a measuring device (not shown).
[0025]
The insulator 5 that insulates the electrode shaft 4 from the connection fitting 3 has electrical insulation as described above, and seals the gap between the electrode shaft 4 and the connection fitting 3, and further includes a boiler or the like. When used as a liquid level sensor, a material having chemical resistance, heat resistance and the like is used. For example, a fluororesin such as PTFE (polytetrafluoroethylene) or PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) can be used. Furthermore, as those having high resistance to hot water, ketone-based synthetic resin materials such as polyether ether ketone and aromatic polysulfone-based synthetic resin materials such as polyether sulfone are preferable.
[0026]
In this embodiment, similarly to the conventional example of FIG. 4 , the electrode shaft 4, the connecting fitting 3 and the insulator 5 are integrally formed by injection molding in a state where the electrode shaft 4 and the connecting fitting 3 are held in a predetermined positional relationship. Then, by crimping the upper end 3b of the integrally formed connecting fitting 3, the insulator 5 is clamped between the annular piece 3a and sealed.
[0027]
The electrode holder 1 _1, as described above, the lower end of the electrode shaft 4, the electrode rod 8, which is suspended in the liquid container 2 via a connecting nut 6 and the clamping bolt 7 is being connected, If the connection nut 6 is too tight, the insulator 5 integral with the electrode shaft 4 tends to rotate integrally with the connection nut 6, so that a thin portion of the insulator 6, that is, an annular piece 3 a is formed. However, in order to prevent such problems, the following structure is adopted. Yes.
[0028]
That is, in this embodiment, as shown in FIG. 2 and FIG. 3 which is a cross-sectional view taken along the cutting plane line AA, the electrode shaft 4, the coupling fitting 3, and the insulator 5 are integrated by injection molding. After the molding, the upper end 3b and the lower end 3f of the connection fitting 3 are caulked.
[0029]
In addition, as shown in FIG. 3, the lower end 3f of the connecting fitting 3 is formed with notches 3h at two opposing positions, whereby the lower end 3f is caulked into the insulator 5 and closely attached. It is configured to make it.
[0030]
In this way, the notch 3h is formed in the lower end 3f of the connecting fitting 3 and caulked so that the connecting fitting 3 is bitten into the insulator 5, so that the electrode rod 8 is connected to the electrode shaft 4 via the connection nut 6. Even when a force to rotate is applied to the electrode shaft 4 when connecting the two, the rotation of the insulator 5 integral with the electrode shaft 4 is prevented by the lower end 3f of the coupling metal 3, thereby Thus, it is possible to prevent the insulator 5 from projecting the annular piece 3a from being twisted or cracked at the thin portion.
[0031]
Thus, since the lower end 3f of the connection fitting 3 is also caulked, as described above, the rotation of the insulator 5 can be prevented, and the sealing performance is improved as compared with the conventional example in which only the upper end 3b is caulked.
[0032]
Note that the number and shape of the notches are not limited to the above-described embodiment, and may be arbitrarily selected.
[0038]
【The invention's effect】
As described above, according to the present invention, the following effects can be obtained.
[0039]
According to the first aspect of the present invention, the notch is formed in the other end of the connecting body and the other end is caulked to be in close contact with the insulator. Therefore, when connecting the electrode rod to the electrode body, Even if a force to rotate the integral insulator acts on it, the other end of the connecting body bites in close contact with the insulator, so that the rotation of the insulator is prevented, It is possible to prevent the insulation from being deteriorated due to thread breakage or cracking at the thin part of the insulator.
[0041]
According to the second aspect of the present invention, since the plurality of notches are provided along the circumferential direction of the cylindrical connecting body, the rotation of the insulator is further reliably prevented, and the threading or cracking of the insulator is prevented. Can be prevented.
[0043]
According to the third aspect of the present invention, the insulator between the projecting portion formed by bending of the coupling body and the one end side to be caulked is tightened to improve the sealing performance.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional view of a first embodiment of the present invention.
FIG. 2 is a partial cross-sectional view showing a manufacturing procedure of the electrode holder in FIG.
3 is a cross-sectional view taken along a cutting plane line AA in FIG. 2;
FIG. 4 is a partial cross-sectional view of a conventional example.
[Explanation of symbols]
1,1 ₁ Electrode holder 2 Liquid container 3 Connecting bracket 3h Notch 4 Electrode shaft

Claims (3)

A connecting body for attaching the electrode holder to the container; and an insulator that surrounds the outer periphery of the electrode body and insulates the electrode body from the connecting body. In the electrode holder that is formed and one end of the coupling body is caulked to clamp the insulator between the one end and the protruding portion,
An electrode holder, characterized in that a notch is formed in the other end of the connecting body, and the other end is caulked to adhere to the insulator.   The electrode holder according to claim 1, wherein a plurality of the notches are formed along a circumferential direction of the tubular connecting body. The protrusion formed on the inner peripheral surface of the cylindrical coupling body, the electrode holder according to claim 1 or 2 are bent to the one side.

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