JPS6011592Y2 - PTC thermistor heating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat generating device using a PTC thermistor circle, and particularly to the above heat generating device which is easy to assemble and requires a small number of parts.

A heating element having a positive temperature coefficient of resistance, typically made of barium titanate, is called a PTC thermistor or a PTC heater.

This PTC thermistor has an automatic temperature control characteristic that automatically controls the amount of heat generated and prevents the temperature from exceeding a certain level because the resistance value increases rapidly above the cue point, so it can be used in heaters, dryers, etc. They are widely used in various household electrical appliances, and are also used as switching, temperature compensation, or temperature sensing elements.

One of these applications is a heat generating device for hair curling.

In the following description, a specific example in which the device of the present invention is applied to a hair curler will be described, but it is not intended that the use of the heat generating device of the present invention be limited to this application.

A hair curling device is a tool that forms curls on the hair by heating the tip of the hair by sandwiching the tip of the hair between a heating cylinder and a hair presser and wrapping the hair around the outer periphery of both.

A plurality of PTC thermistor heating devices are arranged in a row inside the heating cylinder, and heat the outer peripheral surface of the cylinder to a constant temperature.

FIG. 1 shows an example of a heating section of a conventional hair curler.

A plurality of PTC thermistors 1 are arranged in a cylindrical outer container 8, sandwiched between electrode plates 2 and 2'.

Elastic heat transfer plates 4 and 4' are housed outside the electrode plates 2 and 2' with insulating materials 3 and 3' interposed therebetween.

The elastic heat exchanger plates 4 and 4', as shown in FIG. 1b,
The arcuate portion has a flat portion, and the flat portion is in contact with the insulating material, and the arcuate portion is in pressure contact with the inner surface of the cylindrical outer container to act as a spring body.

As a result, the electrode plate 2.2' is brought into pressure contact with the PTC thermistor, and the PTC thermistor is fixed inside the container.

A support body 5 having protrusions at both ends inside the outer container 8
and 6 are placed therein, and these parts are integrated into an integrated structure using rivets, claws 7, and the like.

Reference numeral 10 designates a pivotable hair clip which can be pivoted by suitable means (not shown) between a closed position for clamping hair and an open position as shown.

Although the hair curler of the conventional structure described above exhibits a fairly satisfactory performance, there is still room for improvement in connection with the structure of the PTC thermistor heating device.

The PTC thermistor is fixed from both sides via the insulating material and the electrode plate by elastic heat transfer plates, but this fixation is not perfect, and the PTC thermistor and the insulating material, the electrode plate, and the It is easy to cause scratches in between.

Particularly, in tools such as curlers that are rotated in circles during use, rubbing is likely to occur.

Furthermore, the work of sandwiching the electrode plate and the insulating material between the elastic heat transfer plate and the PTC thermistor is time-consuming and requires the electrode plate to extend beyond the PTC thermistor and protrude to the outside of one of the supports. This results in a lot of wasted material, and the mounting structure for the electrode terminals is not as robust as the one on the left.

In this way, it can be assembled more quickly and easily than before, can be fully used as a heat generating unit before being inserted into the cylinder to be heated, has fewer parts, and has high reliability without failure. There is a need for an operable PTC thermistor heating device.

In view of this situation in the industry, the present inventor devised a PTC thermistor heating device with a new structure.

According to the present invention, electrodes are formed on both sides of a plate-shaped PTC thermistor, and two electrode plates each having a bent part are attached so that one side of the thermistor is in contact with the other along one side edge of the thermistor. Then, the other side is brought into contact with the opposite side edge of the thermistor so that the corners are also in contact with each other, and the PT
A circular C thermistor heating device is provided, which is formed by placing insulators in front and behind a C thermistor, surrounding the whole with a heat-resistant insulating sheet, and fixing the sheet with eyelets at the position of the insulator. .

Referring to FIG. 2, a combination of PTC thermistor electrode plates is shown.

Electrodes 18 are formed on both the upper and lower surfaces of the PTC thermistor 11.

The electrode 18 is formed by plating, coating, baking, or thermal spraying aluminum, which is a mixture of nickel, silver, and a trace amount of base metal.

Reference number 12 is an electrode plate made of stainless steel, for example;
It has a flat portion 12' and a bent portion 12'', and the bent portion 12'' has an extension portion 12''.

Two such electrode plates 12 are placed along diagonally opposite side edges of the PTC thermistor and electrode as shown.

That is, one electrode plate 12 is configured such that its flat portion and bent portion are in contact with the electrode 18 on the top surface of the PTC thermistor and one side of the PTC thermistor, respectively, and the other electrode is configured such that its flat portion and bent portion are in contact with the electrode 18 on the top surface of the PTC thermistor and one side of the PTC thermistor, respectively, and the other electrode is configured such that the bottom electrode and the side surface opposite to the thermistor are in contact with the electrode 18 on the top surface of the PTC thermistor. It is made so that it comes into contact with.

The two electrode plates are of equivalent construction. Electrode plate extension 12
A lead wire 13 is connected to the end of "" by spot welding or the like.

The PTC thermistor heat generating device of the present invention is finally constructed by wrapping the assembly shown in FIG. 2 with a heat-resistant insulating sheet.

At that time, insulators made of asbestos or the like are placed before and after the PTC thermistor.

This aspect is illustrated in FIGS. 3 and 4. It can be seen from FIG. 3 that the insulator 14 abuts the front end face of the PTC thermistor on one side and the rear end face of the PTC thermistor on the other hand and is placed exactly between the electrode plate extensions 12''. .

In this state, the entire body is surrounded by a heat-resistant insulating sheet 17.

As a heat-resistant insulating sheet, Kapton (Dupont Co., Ltd.
S, A) trade name) may be used.

Eyelets, rivets, etc. 16 are attached through the insulator 14 and the heat-resistant insulating sheet 17.

The insulating sheet restrains the PTC thermistor and electrode plate between the insulators.

Eyelets, rivets, etc. fix the insulating sheet 17 to the insulator 14 to prevent it from unwinding.

When the PTC thermistor heating device according to the present invention is used, for example, in a hair curling device, the heating device shown in FIGS.
Elastic heat sinks 4 and 4' are placed inside the outer container δ as shown in the figure.
All you have to do is insert it between the two.

The heat generating device of this invention applies two equivalent electrode plates to the diagonal side edges of a PTC thermistor.

Assembling is easy because the heat generating device can be completed as a unit by simply placing insulators on the front and back, wrapping the whole body in a heat-resistant insulating sheet, and fixing the sheet to the insulator with eyelets, etc. It will be understood that the number of parts is small.

When a device similar to that shown in FIG. 3 according to the present invention was actually used as a hair curling device, stable performance was shown over a long period of time.

Figure 5 shows the temperature rise characteristics when a voltage of AC 120V, 50Hz is applied to a PTC thermistor with a resistance value of 981Ω at 20°C.

Thus, it showed a stable steady state at about 172° C. and 348 W, and this property was stably maintained during long-term use.

.

[Brief explanation of the drawing]

FIG. 1a shows a vertical sectional view of a part of a hair curling device using a PTC thermistor heating device of conventional structure, and FIG. 1b is a sectional view taken along the line A-B in FIG.
The figure is a perspective view showing the arrangement of a PTC thermistor and an electrode plate, FIG. 3 is a partially cutaway top view of the heat generating device of the present invention, and FIG. 4 is a side view of the device of FIG. FIG. 5 is a graph showing the temperature rise characteristics of an example of the heat generating device of the present invention. 1...PTC thermistor, 2, 2'...
・Electrode plate, 3.3'...Insulating material, 4,4'...
...Elastic heat sink, 5.6...Support, 8.
...outer container, 7...eyelet, 10...
...Hair presser, 11...PTC thermistor, 1
B... Electrode, 12... Electrode plate, 12'
...Flat part, 12''...Bent part, 1
2 ''...Extension part, 13...Lead wire, 14...Insulator, 17...Heat-resistant insulation sheet, 16... Eyelets, rivets.

Claims (1)

[Claims for Utility Model Registration] 1. An electrode plate having a plate-shaped PTC thermistor, electrodes formed on both sides of the thermistor, a flat part and a bent part perpendicular to the flat part, the thermistor comprising: A first electrode plate arranged along one side edge of the thermistor with the electrode on one side and the flat part and bent part in contact with the side surface of the thermistor, respectively, and the electrode on the opposite side of the thermistor and the opposite side of the thermistor. and a second electrode plate arranged along a side edge diagonal to the negative side edge of the thermistor, with the flat part and the bent part abutting each other, P consisting of a placed insulator, a heat-resistant insulating sheet surrounding the entire body, and a fixture fixing the sheet to the insulator.
TC thermistor heating device. 2. The PTC thermistor heating device according to claim 1, in which the bent portion of the electrode plate is extended in the longitudinal direction. 3. The PTC thermistor heating device according to claim 1, wherein the heat-resistant insulating sheet is made of Kapton. 4. The PTC thermistor heating device according to claim 1, wherein the electrodes are formed by coating silver.