JP2704928B2 - Electric heating element and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric heating element for heating an object to be heated and a method for manufacturing the same, and more particularly to an electric heating element having a built-in temperature detector and a method for manufacturing the same.

[0002]

2. Description of the Related Art A conventional electric heating element having a built-in temperature controller is composed of an outer tube having an open end, and a heat generator disposed in the outer tube in the axial direction of the tube via an inorganic electric insulator. And a temperature controller connected to the heating element and disposed in the outer tube via the inorganic electric insulator.

[0003] The heating element and the temperature controller are electrically connected in series in the outer tube, and a terminal connected to the heating element and the temperature controller is led out from one opening of the outer tube. ing. That is, the electric heating element divides the outer tube in the tube axis direction into a first region and a second region, and a temperature controller is provided in a second region adjacent in the tube axis direction. A heating element is provided (for example, see Japanese Utility Model Laid-Open No. 4-8397).

[0004]

However, in the electric heating element having the above structure, the temperature controller is exposed to a high temperature when the electric inorganic insulator is filled and in the dehumidifying step of the inorganic electric insulator after diameter reduction. In addition, since the heat causes thermal deformation of the contact portion (bimetal portion) of the temperature controller, there is a problem that the temperature setting of the temperature controller is disturbed and the quality is not stable.

In addition, since the heating element and the temperature controller are incorporated in one outer tube, the outer tube is reduced in diameter to increase the heat conduction of the inorganic electric insulator between the heating element and the outer tube. During processing, there is a problem that the inorganic electric insulator moves and the position of the temperature controller shifts, and the position of the temperature controller becomes unstable.

Further, when the heating element is disconnected, it is necessary to remove the object to be heated from the tank because the outer tube needs to be removed from the tank or the like containing the object to be heated.

Further, since the outer tube directly touches the object to be heated, stress cracking of the outer tube occurs, and depending on the object to be heated, consideration must be given to corrosion (treatment of the metal surface). .

[0008] Therefore, an object of the present invention is to provide a temperature controller which is not affected by heat during processing and can be incorporated at a fixed position of an outer tube, thereby reducing stress cracking and corrosion of the outer tube. An electric heating element is provided.

[0009]

According to the present invention SUMMARY OF], the first jacket tube, the first inorganic electrically insulating material to the first outer tube
A heating element disposed in the tube axis direction through the second outer tube;
A temperature detector disposed in the second outer tube via a second inorganic electric insulator, wherein the temperature detector and the heating element are electrically connected , and the temperature detector and The heating element is connected to a terminal portion led from the inside to the outside of the second armored tube, and the first and second heating elements are connected to each other.
Is an electric heating element joined to each other with these joint surfaces in the radial direction , wherein the first outer tube is embedded in the second outer tube and the second outer tube is provided.
An electric heating element characterized by being joined to the joining surface of the tube is obtained.

According to the present invention, the second outer tube is provided.
Is an opening on the one end side from which the terminal portion is led out.
And a closing portion that closes the other end.
Thus, an electric heating element is obtained.

Further, according to the present invention, a first outer tube,
A tube shaft in the first outer tube via a first inorganic electric insulator;
A heating element disposed in the first direction, a second outer tube, and the second outer tube.
Temperature detection which is disposed through the second inorganic electrically insulating material in Sokan
A temperature detector and the heating element are electrically connected.
And the temperature detector and the light source.
Terminal from which the heat body is led from the inside to the outside of the second outer tube
And the first and second outer tubes are connected to each other.
Are joined together with these radial joining surfaces
One end of the first outer tube in the electric heating element
The portion is joined to the other end of the second outer tube and
2, extending outward from the other end of the outer tube,
In front of the one end of the first sheathing tube and the second sheathing tube
The first and second surfaces are provided on the joint surface with the other end.
Make sure that the screw part that connects the outer
A characteristic electric heating element is obtained.

Further, according to the present invention, a first outer tube,
A tube shaft in the first outer tube via a first inorganic electric insulator;
A heating element disposed in the first direction, a second outer tube, and the second outer tube.
Temperature detector installed in the sheathing pipe via a second inorganic electrical insulator
A temperature detector and the heating element are electrically connected.
And the temperature detector and the light source.
Terminal from which the heat body is led from the inside to the outside of the second outer tube
And the first and second outer tubes are connected to each other.
Are joined together with these radial joining surfaces
One end of the first outer tube in the electric heating element
The portion is joined to the other end of the second outer tube and
2, extending outward from the other end of the outer tube,
One end of the first outer tube and the other end of the second outer tube
The joining surfaces with the ends are joined to each other,
The outer surfaces of the one end of the first outer tube and the other end of the second outer tube are joined by welding.
The electric heating element is characterized by being joined to each other by the fixed portion .

Further, according to the present invention, the first outer tube is provided.
Has an opening at one end of both ends in the tube axis direction.
In addition, an electric heating element having a closed portion at the other end is obtained.

Further, according to the present invention, a step of filling and fixing a heating element in a tube axial direction in a first outer tube via a first inorganic electric insulator, and reducing the diameter of the first outer tube. Process and
A step of dehumidifying the inside of the first outer pipe, a step of closing an opening of the first outer pipe with a sealing member, and connecting one lead wire of a temperature detector to one end of the heating element; after deriving the terminal portions connected to the other end of the other lead wire and the heating element temperature detector out of the opening of the second jacket tube
And joining the first outer pipe to the second jacket tube, the step of covering said temperature detector with a second inorganic electrically insulating material
And a step of closing the opening of the second outer tube with a sealing member.

Further, according to the present invention, the first outer tube is provided.
In the step of joining the second outer tube to the second outer tube,
By the force for joining the outer tube of the above to the first outer tube.
A method for manufacturing an electric heating element, comprising a step of reducing the diameter of the second outer tube .

[0016]

According to the constitution of the present invention, the temperature detector is provided on the second outer pipe on the first outer pipe on which the heating element is disposed, and the heating element is disposed via the inorganic electric insulator. Reduce the diameter of the outer tube and dehumidify it at a high temperature, connect a temperature detector to the terminal portion extended from the heating element, insert the entire body into the second outer tube, and insert the entire tube between the temperature detector and the second outer tube. Then, the diameter of the second outer tube is reduced with an inorganic electric insulator therebetween, and the first outer tube and the second outer tube are joined.

That is, the temperature detector is no longer exposed to the high temperature of the high-temperature dehumidification step for increasing the insulation performance of the inorganic electric insulator interposed between the heating element and the first outer tube, and the temperature is determined by the temperature. The detector can be prevented from wrapping.

Since no temperature detector is provided inside the first outer tube, a reduction in the heat conduction of the inorganic electric insulator interposed between the heating element and the outer tube regardless of the temperature detector. Since the diameter can be adjusted, there is an effect that a highly durable (long life) electric heating element can be formed.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, first to fourth embodiments of the electric heating element of the present invention will be described .
An embodiment will be described with reference to FIGS. In FIG.
The state before joining the second outer tube is shown.

[0020] First, with reference to FIGS. 1 through 4, first to
The electric heating element in the fourth embodiment is
As a part common to both, a first outer pipe 1 and a first inorganic electric insulator 2 in the pipe axis direction of the first outer pipe 1 are provided.
And a temperature detector 7 disposed in the second outer tube 4 with a second inorganic electric insulator 6 interposed therebetween.

The temperature detector 7 and the heating element 3 are electrically connected. In addition, the temperature detector 7 and the heating element 3
Terminals 9a, 9b extending from the inside to the outside of the outer tube 4
Connected to each other.

FIG . 1 shows a first embodiment of the electric heating element of the present invention.
Is shown. Referring to FIG. 1, an electric power generator according to a first embodiment is described.
The first outer tube 1 of the heat body is contained in the second outer tube 4, and the first and second outer tubes 1, 4 are joined to each other by a radial joining surface A thereof. Are joined to each other. This
First exterior tube 1 has an opening, one end of which opens in the
12 and a closing portion 1a whose other end is closed.
ing. The second exterior tube 4 is open at one end.
An opening 18 and a closing portion 4a whose other end is closed.
have.

In the first outer tube 1, a first inorganic electric insulator is provided.
A linear heating element 3 is wound around an insulating bobbin 10 via an edge 2 . In the bobbin 10, as shown in FIG.
In addition, two conductive terminal rods 11a and 11b are provided in the tube axis direction such that both ends of the heating element 3 are in contact with each other. After connecting the heating element 3 to the terminal rods 11a and 11b, the first inorganic electric insulator 2 is filled into the first outer tube 1 . And the first
The heating element 3 is fixed in the first outer pipe 1 by reducing the diameter of the entire outer pipe 1 (reducing the diameter by about 1 to 1.5 m).

Further, at a temperature of about 300 to 700 ° C.,
The opening 12 from which the terminal rods 11a and 11b are led out from the first inorganic electric insulator 2 is sealed with an electrically insulating sealing member 13 after dehumidification in an electric furnace or the like. As the seal member 13, a resin material, an insulator, or the like is employed. afterwards,
One of the lead wires 15a of the temperature detector 7 is connected to the terminal rod 11a connected to the heating element 3, and the other terminal rod 11b is covered with an insulating tube. 4 , the first outer tube 1 is entirely inserted into the second outer tube 4, and the temperature detector 7 is covered with the second inorganic electric insulator 6 . Thereafter, the diameter of the second outer tube 4 is reduced by such a force that the second outer tube 4 is joined to the first outer tube 1. After that, the opening 18 of the second outer tube 4 is closed with a seal member 19.

Here, each of the terminal portions 9a and 9b is a portion connected to the other lead wire 15b and the end of the other terminal rod 11b. A power supply line is connected to the terminal portions 9a and 9b,
At the same time as the heating element 3 is heated, the temperature detector 7 controls ON / OFF of the heating element 3.

FIG. 2 shows a second embodiment of the electric heating element of the present invention .
An example is shown. Note that the same as in the first embodiment shown in FIG.
The same reference numerals are given to the same parts, and the description is omitted.

In the second embodiment, the electric heating element is
One end of the outer tube 1 is the other end of the second outer tube 4
From the other end of the second outer tube 4 to the outside.
Is running. One end of the first outer tube 1 and the second outer tube
4 has a first and a second exterior on a joint surface B with the other end.
A threaded portion for connecting the tubes 1 and 4 to each other is formed .

Both ends of the second outer tube 4 are open. One end of the second outer tube 4 and one end of the first outer tube 1
The other end is joined to each other by screwing with a screw formed on the joint surface B of these ends.

FIG. 3 shows an electric heating element according to the third embodiment. The electric heating element shown in FIG.
Is inserted into the joint surface B between the first outer tube 1 and the second outer tube 4. That is, a step portion 22 having a diameter slightly larger than the diameter of the second outer tube 4 is formed on the inner peripheral surface at one end of the second outer tube 4. The packing material 21 is interposed between the end face of the opening 12 and the radial surface of the step 22. With such a configuration, the first outer tube 1 and the second outer tube 4 can be joined together by the screw at the joint surface B and further sealed with the packing material 21.

FIG. 4 shows a fourth embodiment of the electric heating element of the present invention .
An example is shown. The electric heating element shown in FIG.
Having substantially the same configuration as the electric heating element of the second embodiment.
However, the second point is that there is no screw portion on the joining surface B.
This is different from the embodiment. That is, one of the first outer tubes 1
The joining surface B between the end of the second outer tube 4 and the end of the
They are joined to each other. Furthermore, one of the first outer tubes 1
The outer surfaces of the end and the other end of the second outer tube 4 are
They are joined to each other by the fixing part 25 joined by welding.
Have been.

FIG. 5 shows an electric heating element according to a fifth embodiment, in which a first outer tube 1 and a first inorganic electric insulator 2 are interposed in the tube axis direction of the first outer tube 1. Heating element 3 arranged,
It includes a second outer tube 4 and a temperature detector 7 disposed in the second outer tube 4 via a second inorganic electric insulator 6.

The temperature sensor 7 and the heating element 3, together with the electrically connects, the temperature detector 7 and the heating element 3, the
It is connected to terminal portions 9a and 9b led out of the inside of the first outer tube 1 and the second outer tube 4 . The first and second outer tubes 1 and 4 are joined to each other with their radial joining surfaces A.

That is, the first outer tube 1 and the second outer tube 2 have openings 12, 18, 34a, 3 at both ends, respectively.
4b , and one end of the heating wire 3 is connected to one lead wire 15a . The other end of the heating wire 3
The terminal is connected to the terminal 9b, and the terminal 9b is connected to the first and second terminals.
From the other openings 34a and 34b of the second outer tubes 1 and 4
Led out.

The other lead 15b of the temperature detector 7 is
Lead out from the opening 18 at one end of the second outer tube 2
Terminal portion 9a. Further, the openings 12, 34a at both ends of the first outer tube 1 are sealed by seal members 13, 35, respectively. Also, the second
The opening 18 at one end of the outer tube 2 is
9.

The second electric inorganic insulator 6 in the second outer tube 4 is not limited to this inorganic electric insulator, but may be a silicone resin or the like. Further, the above-described temperature detector 7 has been described using a temperature controller having a thermostat function. However, as another specific example of the temperature detector 7 of the present invention, instead of the temperature controller, , A semiconductor temperature sensor, a thermal protector and the like are used. The thermal protector has both a current limiting function and a thermostat function.
By incorporating it in the electric heating element as a temperature detector,
An electric heating element capable of preventing an overcurrent due to a short circuit of the heating element depending on a use situation and controlling the temperature to a constant temperature is completed.

[0036]

As is clear from the above description, the present invention can provide the following effects.

After the first outer tube having a built-in heat generating portion is dehumidified at a high temperature, a temperature detector can be provided alongside the second outer tube.
Runode, prevents the temperature sensor in the atmosphere is exposed when the high temperature dehumidification, deviation of the temperature detector can be prevented.

Since the filling density of the first outer tube can be increased irrespective of the temperature detector, the life of the electric heating element is improved.

[0039] Since the filling and reduced diameter of the inorganic electrically insulating material of the first jacket tube can prior to binding to the second jacket tube, first
The position of the temperature sensor in the reduced diameter of the outer tube becomes unstable
This can be prevented and set at a fixed position, making this production possible.

By incorporating the first outer tube into the second outer tube and joining the first outer tube, the first outer tube can be prevented from directly touching the object to be heated .

Further, the outer tube is stress relief of the outer tube is not required since there is less temperature difference between the inner surface outer surface.

Also, the first outer tube is placed inside the second outer tube.
By preventing stress cracking and corrosion of the first outer pipe by the second outer pipe by joining and joining, the member can be prevented from flowing out of the cracked portion of the electric heating element to the object to be heated, and furthermore, Relatively inexpensive material setting becomes possible.

Further, the first and second outer tubes are connected at their ends.
The tube when the diameter of the first outer tube is reduced
Adjust the axial dimensional error when joining at the end joint.
Can be adjusted.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of an electric heating element of the present invention.

FIG. 2 is a sectional view showing a second embodiment of the electric heating element of the present invention.

FIG. 3 is a sectional view showing a third embodiment of the electric heating element of the present invention.

FIG. 4 is a sectional view showing a fourth embodiment of the electric heating element of the present invention.

FIG. 5 is a sectional view showing a fifth embodiment of the electric heating element of the present invention.

6 is a perspective view showing a second state, excluding the outer tube of the electric heating body shown in FIG. 1乃optimum Figure 4.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 1st outer tube 2 1st inorganic electric insulator 3 heating element 4 2nd outer tube 6 2nd inorganic electric insulator 7 Temperature detector 9a, 9b Terminal part 10 Bobbin 11a, 11b Terminal rod 12, 18, 30, 31, 34a, 34b opening 13, 19, 35 Sealing member 15a One lead 15b The other lead 21 Packing material 25 Fixing part

Claims (7)

(57) [Claims] And 1. A first jacket tube, first to the first outer tube
A heating element disposed in the tube axis direction via the first inorganic electric insulator , a second outer pipe, and a temperature detector disposed in the second outer pipe via the second inorganic electric insulator Wherein the temperature detector and the heating element are electrically connected , and the temperature detector and the heating element are connected to the second exterior.
It is connected to the terminal part drawn out from the inside of the tube to the outside ,
The first and second outer tubes are provided in an electric heating element which is joined to each other with their radial joining surfaces.
And the first outer tube is built in the second outer tube.
The electric heating element is joined to the joint surface of the second outer tube in a state where the electric heating element is placed. 2. The terminal according to claim 2, wherein said second outer tube extends said terminal portion.
The opening on the one end side and the other end side
And a closed block portion.
2. The electric heating element according to 1 . 3. A first outer tube and a first outer tube inside the first outer tube.
Heating element disposed in the axial direction of the tube via the inorganic electric insulator
, A second outer tube, and a second inorganic electrode in the second outer tube.
A temperature detector disposed through a gas insulator.
That the temperature detector and the heating element are electrically connected
Preferably, the temperature detector and the heating element are the second exterior.
It is connected to the terminal part drawn out from the inside of the tube to the outside,
The first and second outer tubes are connected in a radial direction.
Electric heating elements joined to each other
And one end of the first outer tube is connected to the second outer tube.
Is joined to the other end of the second outer tube.
The first outer tube extends outward from an end.
Between one end and the other end of the second sheath tube
The first and second outer tubes are joined to each other on the joint surface.
An electric heating element , wherein a screw portion is formed . 4. A first outer tube and a first outer tube inside the first outer tube.
Heating element disposed in the axial direction of the tube via the inorganic electric insulator
, A second outer tube, and a second inorganic electrode in the second outer tube.
A temperature detector disposed through a gas insulator.
That the temperature detector and the heating element are electrically connected
Preferably, the temperature detector and the heating element are the second exterior.
It is connected to the terminal part drawn out from the inside of the tube to the outside,
The first and second outer tubes are connected in a radial direction.
Electric heating elements joined to each other
And one end of the first outer tube is connected to the second outer tube.
Is joined to the other end of the second outer tube.
Extending outward from the end, and having one end of the first outer tube.
The joining surface between the end and the other end of the second outer tube is
Are joined to each other, and
Outside of one end and the other end of the second sheath tube
The surfaces are interconnected by a bond that they are welded together.
An electric heating element which is joined to a heating element. 5. The first outer tube is provided with two tubes in the tube axis direction.
One end has an opening and the other end is closed
5. The device according to claim 1, wherein the device has a portion.
Electrical heating element of the mounting. 6. A step of filling and fixing a heating element in a tube axis direction via a first inorganic electric insulator in a first outer tube, a step of reducing the diameter of the first outer tube, and a step of reducing the diameter of the first outer tube. Dehumidifying the inside of the outer tube, sealing the opening of the first outer tube with a sealing member, connecting one lead wire of a temperature detector to one end of the heating element, Joining the first armored tube to the second armored tube after drawing out the other lead wire and the terminal connected to the other end of the heating element to the outside of the opening of the second armored tube; And a step of covering the temperature detector with a second inorganic electric insulator; and a step of sealing an opening of the second outer tube with a sealing member. 7. The first outer tube is connected to the second outer tube.
In the joining step, the second outer tube is connected to the first outer tube.
Reducing the diameter of the second outer tube by the force of joining to the outer tube
7. The method for manufacturing an electric heating element according to claim 6, further comprising the step of :