JPS60205983A - Positive temperature coefficient thermistor heater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an 11 tri-thermal resistor heating element using an aluminum heat radiator which also has electrodes.

Structure of the conventional example and its problems A positive temperature coefficient thermistor is a semiconductor ceramic whose main component is barium titanate; its resistance increases rapidly above a certain temperature. Therefore, when a voltage is applied to this and used as a heating element, self-fi1. A safe product with X degree of groan suppressing effect can be obtained. It is also known that in order to increase the input power at this time, a heat sink may be coupled to the positive temperature coefficient thermistor with a tight thermal coupling.

Generally, aluminum is used as the material for the heat sink, which has excellent thermal conductivity and isoelectricity, is lightweight, easy to process, and has excellent i6i/monocorrosion properties.

Here, in a thermostatic thermistor heating element using an aluminum heat radiator that also serves as an electrode, it is necessary to provide a terminal for power supply on a part of the aluminum heat radiator. Therefore, I will explain one method using Figure 1. A corrugated aluminum heat sink 2 is closely fixed to a flat PTC thermistor 1 with electrodes formed on its main plane using an adhesive (not shown) to form a PTC thermistor heating element. are doing. A flat plate-shaped protrusion 3 is provided on a part of the aluminum heat sink 2, and a hole for screwing is bored at the tip of the protrusion 3.

Then, a lug terminal 4 with a lead wire and generally made of plated brass or the like is connected to a bolt 6, a nut 6,
It is screwed using a washer 7. However, in this case, the protrusion 3 and the lug terminal 4 are made of aluminum. Since it is a joint of metals other than aluminum such as bolts 6, so-called dissimilar metal joints, there is a risk of electrolytic corrosion at the joints of %ξ.

It is mandatory to completely seal it with a coating agent, etc. Therefore, this screw fastening method requires a large number of fastening members such as bolts 5, f≦1z, and requires a large number of man-hours in terms of mass production.

There are many problems, including the need for a coating to prevent electrolytic corrosion. Another method is to use C-rivets instead of screws.However, since the terminals are for heating elements, there is a risk that the joints may loosen due to thermal expansion and contraction, vibration, etc., and cause poor contact. Another method is to join terminals made of materials such as brass or stainless steel using resistance welding, gas welding, ultrasonic welding, or other welding methods. The joining of dissimilar metals by welding has many technical discoveries because the thickness, melting point, hardness, and thermal conductivity of each material (A) are significantly different.

OBJECTS OF THE INVENTION In view of the above-mentioned drawbacks, the present invention provides a positive temperature coefficient thermistor heating element which has a simple structure, requires less man-hours, and can have highly reliable terminals extracted from an aluminum heat radiator that also has electrodes.

Structure of the Invention In order to achieve this object, the positive temperature coefficient thermistor heating element of the present invention has an aluminum heat radiator closely fixed to the electrode surface of a positive custom-made thermistor, and a part of the aluminum heat radiator has
A tongue-shaped protrusion is provided as a power supply terminal, and a
First, insert an insulating tube or use a metal terminal plate coated with an insulating layer such as insulating paint and having multiple barrel-shaped protrusions made of a material other than aluminum, with the protrusions penetrating the insulating layer. Furthermore, a positive temperature coefficient thermistor heating element is constructed by biting into the protrusion of the heat radiating element and fixing it in an electrically conductive state.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. In Figure @2, an aluminum heat dissipation fin e made by continuously bending a thin aluminum plate in a wave shape is placed on the main plane of a flat positive temperature coefficient thermistor 8 with electrodes formed on the main plane.
Then, an aluminum heat dissipating body formed by brazing the aluminum heat dissipating fins 9 with an aluminum plate 1o is tightly fixed using silicone adhesive (not shown) to form a positive temperature coefficient thermistor heat generating body. is configured.

A tongue-like protrusion 11 is provided on a part of the aluminum plate 10 as an aluminum heat sink.

The tip of the protrusion 11 is coated with an insulating paint 12 to a uniform thickness and cured. Then, from the outside of this insulating paint 12, a material other than aluminum, here,
A terminal 13 having multiple barrel-shaped protrusions made of stainless steel is used, and the protrusions penetrate the insulating paint and connect to the aluminum plate 1.
0 into the protrusion 11, and an electrically conductive state is obtained. .

FIG. 3 is a perspective view of the terminal 13, in which a plurality of barrel-shaped protrusions 14 are provided on the part bent into a dogleg shape, and a part can be processed into a faston terminal to draw out the lead wire. It is now possible to do so. Here, the protruding portion of the aluminum plate 10 is inserted into the bent portion in the dogleg shape. Figure 4 shows aluminum plate 1
FIG. 3 is a cross-sectional view showing the state of connection between the protruding portion of No. 0 and the terminal 13;

The tip of the protrusion 11 of the aluminum plate 1o is coated with insulating paint 1.
2, and the terminal 13 is coated from the outside of this insulating layer.
The protrusion 14 breaks the insulating paint 12.

It penetrates and sinks into the protrusion 11, thereby providing electrical continuity between the terminal 13 and the aluminum plate 1o.

According to the configuration shown in Rule 2, the joint portion between the protrusion of the aluminum plate and the terminal made of stainless steel is completely sealed with insulating paint. Therefore, when joining dissimilar metals.

The risk of electrolytic corrosion caused by electrical potential differences can be prevented by making the joint between the protruding part of the aluminum plate and the terminal made of stealth material, which is a dissimilar metal, waterproof. Gain reliability.

In addition, as in this example, the protruding part of the aluminum plate is sandwiched between parts of the terminal, and the barrel-shaped protrusion is inserted into the aluminum, so it has sufficient mechanical strength. Furthermore, there is no risk of poor contact due to thermal expansion/contraction or vibration. Furthermore, since the structure is simple and the number of parts is small, the number of man-hours is reduced in terms of i41 production.
Very few.

Effects of the Invention As described above, according to the present invention, the joint between the metal terminal and the protrusion of the heat sink is completely sealed with the above-mentioned insulating material, thereby preventing electrolytic corrosion caused by joining dissimilar metals. There is no danger of this, and high reliability can be obtained.

At the same time, it is possible to provide a positive temperature coefficient thermistor heating element that has strong mechanical strength and has a simple structure, which greatly reduces the number of man-hours from the perspective of measurement, and its practical effects are great. be.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a conventional PTC thermistor heating element, @2
The figure is a perspective view of a PTC thermistor heating element in an embodiment of the present invention, Figure 3 is a perspective view of a terminal used in a sister example of the present invention, and Figure 4 is a protrusion of an aluminum heat sink in an embodiment of the present invention. FIG. 3 is a cross-sectional view showing the state of the back metal of the terminal. 8...1 [characteristic thermistor, 11...
Aluminum heat sink% 12...Insulating paint, 1
3...Terminal, 14...Protrusion. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 38a

Claims (1)

[Claims] An aluminum heat radiator is fixed in contact with the electrode surface of the positive temperature coefficient thermistor, and a part of the aluminum heat radiator protrudes like a tongue as a power supply terminal.
The tongue piece is coated with an insulating material, and a protrusion extends from the outside of the insulation material and has a metal end that penetrates the insulation material and reaches the tongue piece. (Electric thermistor heating element.