JP3191655B2 - Positive characteristic thermistor heating element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive temperature coefficient thermistor heating element used for heating a fluid such as a hot air heater.

[0002]

2. Description of the Related Art FIG. 4 is a perspective view of a conventional PTC thermistor heating element (hereinafter referred to as a thermistor heating element). FIG.
In the above, 1a to 1f are PTC thermistor elements (hereinafter referred to as thermistor elements) in which electrodes are provided on both main planes,
Reference numerals 2a and 2b denote corrugated metal radiators formed by brazing aluminum, and reference numerals 3a and 3b denote stainless steel terminal plates fixed to the metal radiators 2a and 2b. The metal radiators 2a and 2b are connected to the thermistor element 1
a-1f are thermally applied to both electrode surfaces with an adhesive (not shown),
Electrically and mechanically fixed. Thermistor elements 1a to 1f generate heat when a voltage is applied to the terminal plates 3a and 3b of the thermistor heating element configured as described above, and hot air is obtained when air is passed through the metal radiators 2a and 2b. Further, as is well known, the thermistor elements 1a to 1f are semiconductor ceramics containing barium titanate as a main component, and have a property that the resistance value is low up to a certain temperature and rapidly increases at a temperature higher than that. . Therefore, when a voltage is applied and used as a heating element, it is often used as a heating element having a self-temperature control action.

[0003]

However, in the above-mentioned conventional construction, when the conventional thermistor heating element is used in a bathroom dryer, a dish dryer, etc., the air to be passed through includes a cleaning agent and a bathing agent. , Oil, salt, soy sauce, and the like, and these substances directly contact the thermistor elements 1a to 1f, so that the thermistor elements 1a to 1f may be deteriorated. In order to prevent this, the thermistor elements 1a to
There is also a method of embedding 1f with a silicon resin or the like, but in that case, the thermistor elements 1a to 1f are sealed, and there is no air and a reducing atmosphere is formed, and the thermistor elements 1a to 1f may deteriorate as described above.

An object of the present invention is to solve the above-mentioned problem and to provide a highly reliable thermistor heating element.

[0005]

In order to achieve this object, the present invention provides a method for accommodating a plurality of thermistor elements in an insulating frame, and a convex in the insulating frame for separating PTC thermistors. A hole is formed in the convex portion and opens toward the inside of the insulating frame.

With the above structure, even if a substance that degrades the performance of the thermistor element flows into the insulating frame through the opening, the substance does not directly contact the thermistor element, so that deterioration does not occur. Does not become sealed inside the insulating frame due to the air flowing from the opening, and does not deteriorate at that point.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A thermistor heating element according to a first aspect of the present invention comprises a plurality of thermistor elements, an insulating frame for accommodating the thermistor elements, and electrodes electrically and thermally connected to both the main planes of the thermistor elements. The insulating frame body is provided with a convex portion so as to separate the thermistor elements from each other, and an opening portion is formed in the convex portion toward the inside of the frame body. Things. This configuration prevents contact with substances that degrade the performance of the thermistor element,
The sealed state of the thermistor element can be eliminated.

According to a second aspect of the present invention, the protrusion provided inside the insulating frame is made smaller as it goes inside the frame, and the thermistor element is made of the insulating frame. The closed state is eliminated by forming an air layer so as not to directly contact the inner side surface.

According to a third aspect of the present invention, the size of the cross-sectional area of the opening provided in the insulating frame is reduced toward the inside of the insulating frame. The path of entry of a substance that degrades the performance of the thermistor element can be lengthened.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. FIG. 1 is an exploded perspective view of one embodiment of the present invention, FIG. 2 is a cross-sectional view along the AA plane, and FIG. 3 is a partially enlarged plan view of the insulating frame. 1 to 3,
11a to 11f are thermistor elements provided with aluminum electrodes on both main planes. Reference numerals 12a and 12b denote metal radiators, which are aluminum corrugated fins. Reference numeral 13 denotes an insulating frame formed of a heat-resistant silicone resin.
15a to 15j are projections provided inside the insulating frame 13,
In order to prevent contact between the thermistor elements 11a to 11f, and to prevent the side surfaces of the thermistor elements 11a to 11f from contacting the inner side surface of the insulating frame 13, the size of the thermistor elements 11a to 11f is reduced from the rising portion to the tip. 14a-14j
Is an opening formed in the projections 15a to 15j.
Reference numerals 6a and 16b denote terminal plates made of stainless steel and fixed to the metal radiators 12a and 12b. In the above configuration,
With the thermistor elements 11a to 11f housed and integrated in the insulating frame 13, the upper and lower surfaces thereof
a, 12b and electrically with an adhesive (not shown),
The structure is fixed so as to be thermally connected. In the direction of this thermistor heating element, cleaning agent, bath agent,
Even if oil, salt, soy sauce or the like flows in, the thermistor elements 11a to 11f are protected by the insulating frame 13, so that the thermistor elements 11a to 11f do not come into contact with substances that degrade their performance. Further, thermistor elements 11a to 11f
Thermistor elements 11a to 11a-1 are formed through apertures 14a to 14j formed in the projections 15a to 15j separating the elements.
Since air enters around 1f, the atmosphere does not become a reducing atmosphere due to the closed state, and thermistor elements 11a to 11a
There is no deterioration of f.

The projections 15a to 15j are connected to the insulating frame 1
The reason why the size of the thermistor elements 11a to 11f is reduced toward the inside of the insulating frame 13 is that even if the thermistor elements 11a to 11f are misaligned,
This is because the 11f side surface does not come into contact, and may have a quadrangular pyramid shape or an arc shape as long as the shape satisfies the condition. Further, the opening portions 14a to 14c provided in the convex portions 15a to 15j are further provided.
The reason why the cross-sectional area of 14j is reduced toward the inside of the insulating frame 13 is to lengthen the path of entry of a substance that degrades the performance of the thermistor elements 11a to 11f and to minimize the influence thereof.

[0012]

As described above, according to the present invention, a highly reliable thermistor heating element which can be used even in an atmosphere in which the thermistor element is deteriorated can be provided.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a thermistor heating element according to an embodiment of the present invention.

FIG. 2 is a sectional view of a thermistor heating element according to an embodiment of the present invention.

FIG. 3 is a partially enlarged plan view of a convex portion of the insulating frame according to the embodiment of the present invention.

FIG. 4 is a perspective view of a conventional thermistor heating element.

[Explanation of symbols]

 11a to 11f Thermistor element 12a, 12b Metal radiator 13 Insulating frame 14a to 14j Opening 15a to 15j Convex

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H05B 3/14 F24H 3/04 303

Claims (3)

(57) [Claims] 1. A plurality of PTC thermistors having electrodes formed on both main planes, an insulating frame housing the PTC thermistors, and electrically and thermally connected to the electrodes of the PTC thermistors on both main planes. A metal radiator fixed by an adhesive so as to be connected to the insulating frame; and the insulating frame has a convex portion provided inside the insulating frame so as to separate the positive temperature coefficient thermistors. Positive temperature coefficient thermistor heating element with an opening formed toward. 2. The positive member according to claim 1, wherein the convex portion provided on the insulating frame is formed so as to become smaller toward the inside so that the side surface of the positive temperature coefficient thermistor does not directly contact the inner side surface of the insulating frame. Characteristic thermistor heating element. 3. The PTC thermistor heating element according to claim 1, wherein the size of the cross-sectional area of the opening provided in the insulating frame is reduced toward the inside of the insulating frame.