JPS6126193B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heater that uses positive characteristic porcelain having a large number of through holes as a heating element, and has a large calorific value and excellent electrical reliability.

2. Description of the Related Art Hitherto, heaters using PTC porcelain having a large number of through holes as a heating element have been widely used as heaters for heating various fluids, especially air. For example, as shown in FIG. 1, this heater includes electrodes 4, 4 made of aluminum, zinc, silver, nickel, etc., on both end surfaces 2, 2' of a positive characteristic porcelain 1 having a large number of through holes 3. ', and on the outer periphery of the electrodes 4, 4', an opening dimension d smaller than the external dimension D of the positive characteristic porcelain 1 for supplying electricity to the positive characteristic porcelain 1 is provided.
A pair of power supply terminals 5 and 5' having
It has a structure in which a pair of power supply terminals 5, 5' are attached to the electrodes 4, 4' on both end surfaces 2, 2' of the positive characteristic porcelain 1. When actually used as a heater, a voltage is applied between the pair of power supply terminals 5 and 5' to supply current to the positive characteristic porcelain 1, and at the same time, air is forced to flow through the numerous through holes 3. It exchanges heat and generates a large amount of heat.

However, in the heater structured as shown in FIG. Since the terminals 5 and 5' are closed and air does not flow through the through holes 9 in these areas, there are through holes 9 that do not contribute to heat exchange, so the outer peripheral part of the positive characteristic porcelain 1 does not effectively contribute to heat generation. First, it was not possible to obtain a large calorific value according to the dimensions. In addition, when silver is used for the electrodes 4, 4' provided on both end surfaces 2, 2' having through holes 3, and when the assembled heater is coated with resin etc. to prevent silver migration, positive characteristic porcelain 1 and Since it is not possible to coat the inside of the through hole 9 where air does not flow through the outer periphery where the power supply terminals 5 and 5' are in contact, it is not possible to completely prevent silver migration. When attaching the power supply terminals 5, 5' after applying resin coating to the positive characteristic porcelain 1, the power supply terminals 5, 5'
Pretreatment must be performed to prevent the resin coating from adhering to the surfaces of the electrodes 10 and 10' that contact the power supply terminals 5 and 5', or coatings that have adhered to the electrodes 10 and 10' that are in contact with the power supply terminals 5 and 5' must be removed. In many cases, the process is complicated, and if the coating is not completely removed, there are various problems such as poor contact when electricity is applied.

The heater of the present invention is a heater made in order to solve such problems of the conventional heater, and electrodes are provided on both sides of positive characteristic porcelain having through holes, and a porous material is provided on the electrode surface. This is a heater equipped with a power supply terminal consisting of:

A second example showing a more detailed configuration of the present invention
To explain based on the figure, both end surfaces 2 and 2' having through holes 3 of a positive characteristic porcelain 1 made of barium titanate or the like having a large number of through holes 3 are coated with aluminum, zinc, etc. by thermal spraying, for example, or by baking method. Electrodes 4, 4' made of silver or nickel made by plating method are provided, and on the surfaces of the electrodes 4, 4', power supply terminals 11, 11 made of a mesh-like porous body made of a pair of porous bodies and having through holes 12 are provided. ' are respectively electrode 4,
A pair of power supply terminals 11,
This heater has a structure in which power supply terminals 11, 11' are pressed onto the surfaces of electrodes 4, 4' by tightening screws 6, nuts 7, and insulators 8 between terminals 11'.

Note that the size of each single opening of the through holes 12 constituting the porous portion of the power supply terminals 11, 11' may be any size as long as it does not significantly impede the flow of air through the through holes 3. The dimensions may be as follows,
If the diameter is too small, the ventilation resistance will increase, so the opening diameter of the ventilation hole 12 is set to be smaller than that of the through-hole 3 of the positive characteristic porcelain 1.
It is preferable that it is equal to or larger than .
Further, the width of the grid of the metal body constituting the porous body portion of the power supply terminals 11, 11' is determined by the width of the through-hole 3 of the positive characteristic porcelain 1.
It is preferable that the width is narrower than the minimum width of the through hole 3 of the positive characteristic porcelain 1 in order not to block the flow of air to the porcelain. In addition, the through hole 1 of the power supply terminals 11, 11'
The dimension A of the porous body portion in which the porous body 2 is provided is approximately equal to or larger than the external dimension D of the positive characteristic porcelain 1. This is preferable because the holes 3 can contribute to heat exchange and a larger amount of heat can be obtained.

The material of the power supply terminals 11, 11' may be a material generally used as an electrode material, such as stainless steel, plated iron, copper, etc., or a combination thereof. In addition, the power supply terminal 11,
11' may be formed by forming the outer peripheral part and the porous body part separately, and forming them integrally by adhesion with a conductive substance, soldering, brazing, spot welding, etc., or by pressing a metal plate such as stainless steel or the like. Of course, the outer peripheral part and the porous body part may be integrally formed by etching, or they may be made of wire mesh.

Furthermore, the contact between the power supply terminals 11, 11' and the electrodes 4, 4' is not limited to the method of mechanical pressure contact by tightening with screws 6, nuts 7, and insulators 8 as shown in FIG. The power supply terminals 11, 11' may be bonded to the electrodes 4, 4' with a conductive adhesive or the like, or other methods may be used.

As described in detail above, the heater of the present invention is a heater in which porous power supply terminals are attached to electrodes provided on both end faces of positive characteristic porcelain having many through holes. The power supply terminal can be attached to the electrode surface of positive temperature porcelain without blocking the through holes in the porcelain, and all the through holes in positive temperature porcelain can contribute to heat exchange, resulting in a large amount of heat generation. It is something.
Furthermore, since the power supply terminal is porous, there are many contact areas on the electrode surface where the power supply terminal and the electrode come into contact, resulting in excellent contact reliability.Also, when silver is used for the electrode, it is necessary to prevent silver migration. Even when coating is applied, since the power supply terminal is a porous body, at least the entire area near the electrode of the positive characteristic porcelain can be easily coated, so that migration of silver can be completely prevented. Therefore, it is a heater that can generate a large amount of heat and has excellent electrical reliability, so it can be used safely for a long period of time, and is suitable for hair dryers, roll brush dryers, hot air heaters,
It can be used as a clothes dryer, futon dryer, and other air heating heaters, and is an extremely useful heater in industry.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a specific example of a conventional heater whose heating element is positive characteristic porcelain having a large number of through holes, and FIG. 2 is an explanatory diagram showing a different specific example of the heater of the present invention. be. 1... Positive characteristic porcelain, 2, 2'... Surface having through holes, 3... Through holes, 4, 4'... Electrodes, 5,
5'...Power supply terminal, 6...Screw, 7...Nut,
8...Insulator, 9...Through hole through which air does not flow,
10, 10'... Electrode in contact with the power supply terminal, 11,
11'... Power supply terminal having a porous body portion, 12...
Through hole, d...Opening size of power supply terminal, D...External dimensions of positive characteristic porcelain, A...Dimensions of porous body part of power supply terminal.

Claims (1)

[Scope of Claims] 1. A heater characterized in that electrodes are provided on both sides of positive characteristic porcelain having through holes, and a power supply terminal made of a net-like porous body is attached to the electrode surface. 2. The heater according to claim 1, wherein the porous body portion of the power supply terminal is in contact with the entire surface of both surfaces of the positive characteristic porcelain having through holes. 3. The heater according to claim 1, wherein the diameter of the porous body of the power supply terminal is equal to or larger than that of the surface of the positive characteristic porcelain having the through holes. 4 The width of the lattice that constitutes the porous body part of the power supply terminal is
The heater according to claim 1, wherein the heater is narrower than the minimum width of the through hole of the positive characteristic porcelain. 5. The heater according to claim 1, wherein the opening diameter of the through hole constituting the porous body portion of the power supply terminal is equal to or larger than the through hole diameter of the positive characteristic porcelain.