JPH0120788Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a heating element unit suitable for use as a heater in a hair iron or the like.

Conventionally, as shown in FIGS. 1a and 1b, this type of heating element unit connects metal terminal plates 3 and 4 through spacers 1 and 2 made of insulated porcelain, and connects them to metal grommets 5 and 6. 7 and 8, and a positive temperature coefficient thermistor 11 having electrodes 9 and 10 is sandwiched and held between both metal terminal plates 3 and 4.

After configuring as described above, by connecting a power source to the lead connection parts 12 and 13 of the metal terminal plates 3 and 4, current flows from the metal terminal plates 3 and 4 to the positive temperature coefficient thermistor 11 through the electrodes 9 and 10. The characteristic thermistor 11 generates heat. This generated heat is conducted to a heat dissipation plate (not shown) that is in contact with the metal terminal plates 3 and 4, and is used as a double-sided heater.

In these conventional configurations, the metal terminal plates 3 and 4 are
Since it is fixed to the spacers 1 and 2 at diagonal positions by metal eyelets 6, 7 and 5, 8,
The metal terminal plates 3, 4 are twisted and distorted, and the close contact between the positive temperature coefficient thermistor 11 and the metal terminal plates 3, 4 becomes poor, resulting in a decrease in thermal conductivity, and the contact between the metal terminal plates 3, 4 and the electrodes 9, 10. There were disadvantages such as poor contact between the two.

The object of the present invention is to provide a heating element unit in which no force that would cause twisting of the terminal board is applied.

Therefore, the present invention includes a pair of terminal plates that sandwich the upper and lower main heating surfaces of a plate-shaped PTC thermistor at approximately the center, and insulating spacers that hold these terminal plates on both sides of the PTC thermistor. These insulating spacers are provided with protrusions on the top and bottom, respectively, and these protrusions are fitted into holes provided in the center of the terminal board in the width direction, and the ends of the protrusions protruding from the holes of the terminal board are deformed or the protrusions are The terminal plate is fixed to the spacer by engagement with the hole in the terminal plate.

Since a hole into which the protrusion of the spacer fits is formed at the center in the width direction, the terminal board is fixed at a symmetrical position above and below the insulating spacer. This results in
No force is applied to the terminal board that would cause it to twist.

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

In FIG. 2, reference numeral 21 denotes a positive temperature coefficient thermistor, in which a positive temperature coefficient thermistor material is molded into a rectangular (or circular, etc.) plate shape and fired, and electrode films 21a and 21b are formed on the upper and lower main heating surfaces, respectively;
22 is a pair of terminal plates that sandwich the upper and lower main heat generating surfaces of the PTC thermistor 21 approximately at the center; 23;
Insulating spacers 24 hold these terminal plates 22, 22 on both sides of the positive temperature coefficient thermistor 21.

The terminal plates 22, 22 are both formed by punching metal plates such as brass, and are shown in FIG. 3a.
As shown in FIG. 2, a lead wire connection piece 26 having a certain width is protruded from one end of one short side of the rectangular terminal board main body 25, and the terminal board main body 2
5 are provided with protrusions 27, 27 and 27, 27 (third
Terminal plate fixing holes 28, 28 having a shape matching the shape shown in Fig. c) are provided.

The terminal board fixing holes 28, 28 are formed so that their centers are located on the longitudinal center line of the rectangular terminal board main body 25.

The terminal board fixing holes 28, 28 can have any shape such as circular or square, but in order to prevent the spacers 23, 24 from rotating freely, they should be square or other square. It is preferable that there be.

On the other hand, the insulating spacers 23 and 24 are made of resin such as Teflon or polyphenylene, which has good heat resistance and is easy to mold.
These insulating spacers 23 are molded into a rectangular parallelepiped shape having a height approximately equal to the thickness of
The above-mentioned rectangular (or circular, etc.) projections 27, 27 and 27, 27 are provided on both upper and lower surfaces of the
Each stands out.

The projections 27 of the insulating spacers 23 and 24,
27 and 27, 27 are the protrusions 27, 27 on the insulating spacer 23 side, as shown in FIGS. 3b and 3c.
is the lead wire connection piece 26 of the terminal board body 25, 25,
The terminal board fixing holes 28, 28 on the 26 side, and the protrusions 27, 27 on the insulating spacer 24 side are connected to the terminal board main body 2.
5 and 25 into the other terminal board fixing holes 28 and 25, respectively, and crush the tips thereof by a method such as heat welding, and then attach the terminal boards 22 and 22 to the insulating spacers 23 and 24.
As shown in FIG. 2, a positive temperature coefficient thermistor 21 is sandwiched approximately at the center of these terminal plates 22, 22.

If you do the above, the terminal board bodies 25, 25
is the insulating spacer 2 on its longitudinal center line.
3 and 24, and the terminal board body 2
5, 25 will not be twisted, and there will be no heat conduction failure or damage to the terminal board body 25, 25 and the positive temperature coefficient thermistor 2.
Poor contact with the first electrode films 21a, 21a can be eliminated.

Note that in the above embodiment, the insulating spacer 2
3 and 24 are formed separately into a spacer part 31 and a projection member 32, as shown in FIG. 4a, and as shown in FIG. The protrusion 32 may be fitted into the fitting hole 31a.

Furthermore, if a rivet-shaped protrusion member 33 or 34 shown in FIGS. 5a and 5b is used instead of the protrusion member 32, only one end of the protrusion member 33 or 34 can be heated during assembly of the heat generating unit. It is only necessary to deform it by welding or the like, and assembly becomes easy.

Next, another embodiment of the present invention is shown in FIG.

In the embodiment shown in FIG. 6, in place of the insulating spacers 23 and 24 in the embodiment shown in FIG.
An insulating spacer 4 with a plug-in structure into which both ends of the terminal board bodies 25 and 25 of 2 and 22 are inserted and fixed, respectively.
1,42 is used.

As shown in FIGS. 7a and 7b, the insulating spacer 41 has fitting grooves 43, 43 into which one end of each of the terminal board bodies 25, 25 is fitted, and through which the lead wire connection pieces 26, 26 pass, These fitting grooves 4
Right triangular locking protrusions 44, 44 protrude from the side walls 3, 43 toward the center of the insulating spacer 41 in the thickness direction.

The locking protrusions 44, 44 fit into the terminal plate fixing holes 28, 28 of the terminal plate main body 25, and
The surfaces projecting perpendicularly to the side walls of 3 and 43 engage one of the inner circumferential walls of the fitting grooves 43 and 43, respectively, to prevent the insulating spacer 41 from slipping out.

On the other hand, the insulating spacer 42
It has insertion grooves 45, 45 into which the other ends of the terminal board fixing holes 28, 45 of the terminal board bodies 25, 25 are inserted, and from the side walls of these insertion grooves 45, 45, the terminal board fixing holes 28,
Locking protrusions 46, 46 which are fitted into the terminal plates 28 and prevent the terminal boards 22, 22 from coming off are projected.

If you do the above, when assembling the heat generating unit,
The terminal plates 22, 22 can be easily attached to the insulating spacers 41, 42, which is convenient.

In the above explanation, basic embodiments of the present invention have been described, but the present invention is not limited to the above embodiments, and various configurations can be made within the scope of the gist of the present invention.

For example, although not specifically shown, the terminal boards 22, 22 have biting blades that bite into the outer periphery of protrusions provided on resin insulating spacers, and these biting blades insulate the terminal boards 22, 22. It may be fixed to a spacer.

As is clear from the detailed description above, the present invention is designed to prevent the terminal board from deforming the protrusions provided on the insulating spacer at symmetrical positions above and below the insulating spacer, or by changing the relationship between the terminal board and the inner wall surface of the hole provided in the terminal board. Since it is fixed to an insulating spacer, there is no force applied to the terminal board that would cause it to twist, and the contact between the terminal board and the positive temperature coefficient thermistor is improved, allowing heat to be extracted efficiently. . Further, in the present invention, since the center portion of the terminal plate in the width direction is fixed, there is no floating phenomenon of the terminal plate, and the close contact with the positive temperature coefficient thermistor can be improved.

In addition, since the present invention does not use metal eyelets like the conventional ones, there is no need to consider the electrode spacing within the same plane, and the heat generating unit can be made smaller. Since it does not require minute parts, it also has the advantage of reducing component costs and assembly costs.

[Brief explanation of drawings]

Figure 1a is a plan view of a conventional heat generating unit;
Figure b is a front view of the conventional heat generating unit, Figure 2 is a front view of the heat generating unit according to the present invention, Figure 3 a is a plan view of the terminal board, and Figure 3 b is an assembly of the heat generating unit according to the present invention. FIG. 3c is a front view for explaining the assembly of the heat generating unit according to the present invention, FIG. 4a is an exploded perspective view of a modification of the insulating spacer, and FIG. 4b is a fourth FIG. 5 is an assembled view of FIG. Figure 7a is the 6th
FIG. 7b is a plan view of the terminal plate and insulating spacer of the heating unit shown in the figure, and FIG. 7b is a sectional view taken along the line A-A' in FIG. 21...Positive characteristic thermistor, 22...Terminal board,
23, 24...Insulating spacer, 27...Protrusion, 2
8...Terminal board fixing hole, 31...Spacer part, 3
2, 33, 34... Projection member, 41, 42... Insulating spacer, 44, 46... Locking projection.

Claims (1)

[Scope of utility model registration request] A pair of terminal plates sandwiching the upper and lower main heating surfaces of a plate-shaped positive temperature coefficient thermistor approximately at the center, and insulating spacers that hold these terminal plates on both sides of the positive temperature coefficient thermistor. Protrusions are provided in each of the terminal plates, and these protrusions are fitted into holes provided in the center of the width direction of the terminal board, and the ends of the protrusions protruding from the holes in the terminal plate are deformed or the protrusions are inserted into the holes in the terminal plate. A heating element unit characterized in that a terminal plate is fixed to a spacer by engagement.