JPS5914234B2 - Electric heating element for hot air fan - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electric heating element for a Fuchika fan used for drying, heating, etc.

Conventional heating elements of this type can be broadly classified into metal heating elements and non-metal heating elements. Metal heating elements are generally made of metal wires such as nichrome wire, and are superior in that they are small and have a simple structure, but when the blower fan stops, the heating element may overheat and break. 5. There are problems such as the need for temperature phases and the need for a temperature controller or the like to keep the temperature of the hot air constant. A conventional example used as a non-metallic heating element is one in which barium titanium octate semiconductor porcelain having positive resistance-temperature characteristics (PTC characteristics) is formed into a honeycomb shape.

In this type of heating element, a large current flows in the initial stage of energization, but when it reaches a certain temperature, the current rapidly decreases and the temperature rise is automatically limited, so the temperature can be controlled like a metal heating element. It is advantageous in that it does not require a container or a humidity fan, but since it is a sintered porcelain body, there are restrictions on size.
Moreover, it has the disadvantage that it is difficult to mold and easily breaks. The object of the present invention is to provide an electric heating element that does not have the above-mentioned drawbacks, has PTC characteristics similar to the above-mentioned barium tannate semiconductor porcelain, and has a large size. This is an electric heating element that has no limitations on heat, is easy to manufacture, and has no risk of damage.

An embodiment of the present invention will be explained with reference to FIGS. 1 to 3.

Reference numeral 1 denotes a heat-resistant insulating substrate, which is made of an iron plate with an enameled surface or a plastic film laminated on aluminum foil, and has a large number of through holes 2 formed therein.

3 and 3' 11 are pairs of band 30-shaped electrodes provided on both sides of the surface of the substrate 1, and are formed by applying and baking silver paste or pasting copper foil.

Reference numeral 4 denotes a resistor film made of synthetic resin and carbon black that is uniformly provided over almost the entire surface of the substrate 1 between the electrodes 3 and 3' on both sides.

This resistor coating is made by kneading and finely pulverizing a crystalline resin such as polyvinylidene fluoride resin and carbon black, and then kneading this with a solvent and a binder to form a resistor ink. After being applied by means such as printing, it is fixed by baking. The electric heating element of the present invention is completed by stacking a plurality of unit heating plates (four in the figure) formed as described above and tightening the four corners with bolts 5. Note that the bolt 5 is attached to the electrode 3.3' to serve as a connection terminal.
Penetrate and tighten. When a plurality of unit heating plates are stacked, a ventilation path is formed by communicating the respective through holes 2, and in order to prevent air leakage from the surroundings, there is a space between the substrates. A heat-resistant packing 6 is interposed around it. 4 and 5 are other embodiments of the present invention,
In the embodiments shown in FIGS. 1 to 3, the resistor film 4 is provided on almost the entire surface of the substrate 1, whereas in the embodiments shown in FIGS. ' They are provided in a strip shape with a constant interval between them. FIG. 6 shows a blower using the electric heating element 7 of the present invention, where 8 is a housing and 9 is a blower fan.
As described above, the present invention provides a pair of band-shaped electrodes 3, 3' on both sides of the surface of the heat-resistant insulating substrate 1, and also provides a large number of through holes 2 between the band-shaped electrodes 3, 3'. A unit heat generating plate is constructed by providing a resistor coating 4 having a positive resistance intensity coefficient on the entire surface or in the form of a band at constant intervals b, and the unit heat generating plate is communicated with the above-mentioned ventilation holes to provide ventilation. Since multiple sheets are laminated and fixed via heat-resistant packing 6 around the periphery to form a path, the advantages of the conventional electric heating element mentioned at the beginning are obtained, the disadvantages are eliminated, and the effects described below are achieved. play.

(1) The resistor coating 4 has the PTC characteristic as shown in FIG. 7, and has a self-vorticity control effect as described above, so that there is no need for a convergence control device, a width phase, etc. (2) Since the resistor coating is applied and fixed to a heat-resistant insulating substrate by baking, it can be easily processed into any shape and size, and there is no risk of breakage like with porcelain heating elements. There is no.

[Brief explanation of drawings]

Figure 1: Plan view of the embodiment of the present invention, Figure 2: Figure 1 AB
3: A side view of FIG. 1, FIG. 4: A plan view of another embodiment of the present invention, FIG. 5: A sectional view along the CD line of FIG. 4, FIG. 6: The present invention Figure 7: Graph showing the resistance and depth characteristics of the present invention, 1...
・Substrate, 2...Through hole, 3, 3'...Electrode, 4...Resistor coating, 5...Bolt, 6... ... Packing, 7... Electric heating element.

Claims (1)

[Scope of Claims] 1 A heat-resistant insulating substrate is provided with a large number of through holes, a pair of strip electrodes are provided on both sides of the substrate, and a resistor film having a positive temperature coefficient of resistance is provided between the electrodes to produce a unit heat generating plate. What is claimed is: 1. An electric heating element for a hot-air fan, characterized in that a plurality of unit heating plates are stacked and fixed so that the through holes communicate with each other to form a ventilation path. 2. The electric heating element for a hot air blower according to claim 1, wherein the resistor coating is uniformly provided over substantially the entire surface of the substrate between the electrodes. 3. The electric heating element for a warm air machine according to claim 1, wherein the resistor coating is provided in a band shape at a constant interval between the electrodes on the surface of the substrate. 4. The electric heating element for a hot air blower according to claim 1, wherein the unit heating plate is laminated around the unit heating plate with a heat-resistant packing interposed therebetween.