JP7013288B2 - Ceramic heater - Google Patents

Description

The present invention relates to a ceramic heater used for, for example, a warm water washing toilet seat, a fan heater, an electric water heater, a 24-hour bath, a soldering iron, a hair iron and the like.

Conventionally, for example, a heat exchange unit having a resin container (heat exchanger) has been used for a hot water washing toilet seat, and the heat exchange unit is used to warm the washing water contained in the heat exchanger. , A long pipe-shaped ceramic heater is arranged.
As shown in FIG. 4, as this ceramic heater, a ceramic sheet 190 on which a heat generating resistor 400 to be a heater wiring circuit is printed is wound around a cylindrical ceramic porcelain tube 130 and integrally fired (patented). See Document 1).
Then, the gap between the inner wall of the heat exchanger and the outer circumference of the ceramic heater and the water flowing in the ceramic porcelain tube are heated by the ceramic heater.

By the way, when the ceramic heater is heated in a dry state when the water is cut off, a potential difference is generated between the terminal wirings 401 and 402 of the heat generating resistors 400 facing each other across the wound portion 191 of the ceramic sheet 190, and this is generated. The glass component present in the nearby ceramic sheet 190 may melt. In this case, the ceramic component and the wiring ink component in the ceramic sheet 190 are ionized, causing migration M to move, and the heater characteristics may deteriorate.
Therefore, in the heater described in Patent Document 1, the potential difference is suppressed by defining the dimensions of the end wirings 401 and 402 facing each other across the winding portion 191 and the applied voltage.

JP-A-2017-183070 (FIG. 4, paragraphs 0029, 0038)

By the way, although the heater described in Patent Document 1 is used with alternating current, it is described that this heater may be used with direct current. When the heater is used with direct current, for example, power supply from DC power generation by a household power generation device (fuel cell, solar power generation) is assumed, and when the heater is used with alternating current, when the power generation device is stopped. Power supply from the AC power source is assumed.
However, when the heater described in Patent Document 1 is used with direct current, the above-mentioned migration may become remarkable. This has the effect that even if the ceramic component and the wiring ink component in the ceramic sheet 190 are ionized in the case of alternating current, the ions return in the opposite direction when applied in the opposite polarity by alternating current, and migration is reduced. On the other hand, in the case of direct current, since the polarity is constant, the effect of returning ions does not occur, and migration gradually proceeds.

That is, when direct current is applied to the heater, it is necessary to design a circuit that becomes a heat generation resistor so that migration is reduced. On the other hand, it is difficult in terms of space to arrange a DC heater and an AC heater separately in one warm water washing toilet seat, which leads to an increase in cost.
Therefore, an object of the present invention is to provide a ceramic heater which has two heat generation resistors, one for direct current and the other for alternating current, and suppresses deterioration of heater characteristics due to direct current energization and is compact.

In order to solve the above problems, the ceramic heater of the present invention is formed on a tubular ceramic support extending in the axial direction, a ceramic sheet arranged in contact with the outer periphery of the support, and the ceramic sheet . In a ceramic heater including at least a heat-generating resistor, as the heat-generating resistor, an AC heat-generating resistor connected to an external AC power supply and a DC heat-generating resistor connected to an external DC power supply are separately separated . When viewed in a cross section that is perpendicular to the axial direction and includes the heat -generating resistor, the second ends forming both ends of the DC heat-generating resistor form a winding portion of the ceramic sheet around the support. It is characterized in that each of the first ends facing each other and forming both ends of the AC heat generation resistor is arranged between each of the second ends and the winding portion .

According to this ceramic heater, when the ceramic heater is heated in a dry state when water is cut off, even if a potential difference occurs between the second ends forming both ends of the DC heat generation resistor, the distance between the second ends is the second. Moved away by one end. Therefore, the heat generation of the ceramic sheet near the second both ends is reduced, and the deterioration of the heater characteristics due to migration can be suppressed. Further, migration is also reduced by interposing the first end end between the second end ends.
Further, it is not necessary to install two ceramic heaters, one for direct current and the other for alternating current, so that the heater can be made compact and the cost can be reduced.

In the ceramic heater of the present invention, the DC heat generation resistor may be at least 600 ° C. or higher when energized.
When the heat generation resistor for direct current becomes 600 ° C. or higher when energized, migration is more likely to occur, so that the present invention is further effective.

In the ceramic heater of the present invention, a voltage higher than that of the first end may be applied to the second ends forming both ends of the DC heat generation resistor.
Even when a voltage higher than that of the first end is applied to the second end, migration is more likely to occur, so that the present invention is further effective.

According to the present invention, it is possible to obtain a ceramic heater having two heat generating resistors, one for direct current and the other for alternating current, which suppresses deterioration of heater characteristics due to direct current energization and is compact.

It is a front view which shows the ceramic heater and the power supply device which concerns on embodiment of this invention. It is a developed view which shows the ceramic sheet of a ceramic heater. It is sectional drawing which follows the AA line of FIG. It is a partial cross-sectional view which shows the heat generation resistor of a conventional ceramic heater.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 is a front view showing a ceramic heater 11 and a power supply device 100 according to an embodiment of the present invention, FIG. 2 is a developed view showing a ceramic sheet 19 of the ceramic heater 11, and FIG. 3 is taken along the line AA of FIG. It is a cross-sectional view.
The ceramic heater 11 according to the embodiment of the present invention can be used to heat the washing water, for example, in the heat exchanger of the heat exchange unit of the warm water washing toilet seat.

As shown in FIG. 1, the ceramic heater 11 is connected to the power supply device 100 and generates heat by the DC power and the AC power supplied from the power supply device 100.
First, the power supply device 100 includes an AC power supply 102 and a DC power supply 104, and the AC power supply 102 and the DC power supply 104 are energized and controlled by a power supply control unit 106. Further, the AC electric wire 102a from the AC power source 102 and the DC electric wire 104a from the DC power source 104 are connected to the ceramic heater 11, respectively.
The power supply device 100 is installed on the warm water washing toilet seat.

The ceramic heater 11 is joined to the outer periphery of the ceramic substrate 13 via a bonding member 20 with a tubular ceramic substrate 13 in which an AC heating resistor 41 and a DC heating resistor 42, which will be described later, are embedded, and is annular. Alternatively, it is provided with an ended annular ceramic flange 30.
The ceramic substrate 13 includes a cylindrical ceramic support 17 extending in the L direction of the axis and a ceramic sheet 19 wound around the outer periphery of the support 17, and the support 17 has a through hole 17h in the L direction of the axis. (See FIG. 3). Then, in the heat exchanger, the water flowing inside the through hole 17h is heated by the ceramic heater 11, and the water in the gap between the inner wall of the heat exchanger and the outer periphery of the ceramic heater is also heated by the ceramic heater 11.
The support 17 and the ceramic sheet 19 can be formed from, for example, alumina. The ceramic sheet 19 does not completely cover the outer periphery of the support 17, and the wound portion 19a of the ceramic sheet 19 is formed with a slit-shaped groove portion 13s extending along the axis L direction of the support 17.

On the other hand, as shown in FIG. 2, on the ceramic sheet 19, an AC heat generation resistor 41 and a DC heat generation resistor 42 having a plurality of heater wiring circuits 41a and 42a having a meandering pattern shape are formed by printing or the like. ing.
Specifically, in the heater wiring circuit 41a constituting the AC heat generation resistor 41, the folded portions at both ends of the plurality of wirings extending along the axis L direction extend in the width direction and are connected to the ends of the adjacent wirings. It is in the form of being. The two first ends 41e forming both ends in the circumferential direction of the heater wiring circuit 41a are integrally connected to the two pad-shaped connection terminals 41b at one end in the axis L direction.
Similarly, in the heater wiring circuit 42a constituting the DC heat generation resistor 42, the folded portions at both ends of the plurality of wirings extending along the axis L direction extend in the width direction and are connected to the ends of the adjacent wirings. Form. The second ends 42e forming both ends in the circumferential direction of the heater wiring circuit 42a are integrally connected to the two pad-shaped connection terminals 42b at one end in the axis L direction.

The two connection terminals 41b are electrically connected to the two external terminals 43 formed on the outer peripheral surface of the ceramic sheet 19 via via conductors (not shown) or the like.
Similarly, the two connection terminals 42b are electrically connected to the two external terminals 44 formed on the outer peripheral surface of the ceramic sheet 19 via via conductors (not shown) or the like.
Further, by connecting the external terminal 43 to the AC electric wire 102a, an AC current flows through the AC heat generation resistor 41. Further, by connecting the external terminal 44 (not shown) to the DC electric wire 104a, a DC current flows through the DC heat generation resistor 42.
The AC heat-generating resistor 41 and the DC heat-generating resistor 42 (including the connection terminals 41b and 42b) can be formed, for example, with tungsten as a main component.

Here, as shown in FIGS. 2 and 3, when viewed in a cross section perpendicular to the axis L direction and including the heat generation resistor, the two first end ends 41e are arranged adjacent to each other in the circumferential direction. Specifically, the two first end ends 41e face each other with the groove portion 13s interposed therebetween, and each of the two second end ends 42e moves away from the first end end 41e in the circumferential direction on the opposite side of the groove portion 13s (the groove portion 13s). ) Oppose at the position.
That is, the DC heat generation resistor 42 is provided separately from the AC heat generation resistor 41, and the first end 41e is arranged between the second end 42e and the groove portion 13s.
As a result, when the ceramic heater 11 is heated in a dry state when water is cut off or the like, even if a potential difference occurs between the second both ends 42e, the distance between the second both ends 42e is increased by the first both ends 41e. Therefore, the heat generation of the ceramic sheet 19 near the second both ends 42e is reduced, and the deterioration of the heater characteristics due to migration can be suppressed. Further, migration is also reduced by interposing the first both ends 41e between the second both ends 42e.
Further, it is not necessary to install two ceramic heaters, one for direct current and the other for alternating current, so that the heater can be made compact and the cost can be reduced.
In the alternating current heating resistor 41 to which alternating current is applied, the polarity changes alternately between the first both ends 41e, so that migration is less likely to occur even if the first both ends 41e are close to each other.

As shown in FIG. 3, the ceramic sheet 19 has an endless ring shape and is arranged in contact with the outer periphery of the support 17. Further, the fact that the ceramic heater 11 has the ceramic sheet 19 and the support 17 (that is, different from the one in which the ceramic sheet 19 and the support 17 are indistinguishable) is supported by the ceramic sheet 19 in the cross section of FIG. It can be seen from the observation of the boundary with the body 17.
Further, as shown in FIG. 2, in order for each of the two second end ends 42e to face each other at a position opposite to the first end end 41e in the circumferential direction at the position opposite to the groove portion 13s, the heater wiring circuit 42a is a heater wiring circuit. It needs to be arranged inside 41a. However, the position of the connection terminal 42b does not matter as long as it overlaps with the connection terminal 41b.

When the temperature of the DC heat generation resistor 42 is at least 600 ° C. or higher during energization, migration is more likely to occur, so that the present invention is further effective.
Further, when a voltage higher than that of the first end 41e is applied to the second end 42e, migration is more likely to occur, so that the present invention is further effective. For example, a DC voltage of about 400 V can be applied to the second end 42e, and an AC voltage of about 100 V can be applied to the first end 41e.

The ceramic heater 11 can be manufactured, for example, as follows.
First, a member to be a support 17 is extruded from a slurry of ceramic powder such as alumina and calcined. Further, a green sheet to be a ceramic sheet 19 is formed from the same slurry as described above, and the metallized ink to be an AC heat generation resistor 41 and a DC heat generation resistor 42 as shown in FIG. 2 is printed on the surface thereof. dry. Then, another green sheet is laminated and pressed on the printed surface of this green sheet, and the AC heat generation resistor 41 and the DC heat generation resistor 42 are embedded between the two green sheets. Further, vias are provided on one side of the laminate of both green sheets to fill the via conductor, and the conductive pastes to be the external terminals 43 and 44 are printed and dried directly above.
Then, a ceramic paste is applied to the opposite surfaces of the laminated bodies of both green sheets, wrapped around the support 17 and adhered, and the whole is fired.
Further, a ceramic powder such as alumina is pressure-molded with a mold and fired to obtain a flange 30.

The ceramic substrate 13 and the flange 30 manufactured in this manner are heated to a temperature equal to or higher than the melting temperature of the glass by arranging the solid bonding material 20 (glass) to be the bonding member 20 in the gap between the ceramic substrate 13 and the flange 30. The flange 30 is joined to the outer periphery of the ceramic substrate 13.

It goes without saying that the present invention is not limited to the above embodiments and extends to various modifications and equivalents included in the idea and scope of the present invention.
The shapes of the AC heat generation resistor 41 and the DC heat generation resistor 42 are not limited.
The material of the resistor ink is also not limited.

11 Ceramic heater 17 Support 19 Ceramic sheet 41 Heat-generating resistor (AC heat-generating resistor)
41e 1st both ends 42 Heat generation resistor (DC heat generation resistor)
42e 2nd both ends 102 AC power supply 104 DC power supply L axis

Claims (3)

In a ceramic heater including at least a cylindrical ceramic support extending in the axial direction, a ceramic sheet arranged in contact with the outer periphery of the support, and a heat generating resistor formed on the ceramic sheet .
As the heat generation resistor, an AC heat generation resistor connected to an external AC power supply and a DC heat generation resistor connected to an external DC power supply are separately provided.
When viewed in a cross section perpendicular to the axial direction and including the heat generation resistor
The second ends forming both ends of the DC heat generation resistor face each other with the wound portion of the ceramic sheet on the support interposed therebetween, and the first ends forming both ends of the AC heat generation resistor are respectively. A ceramic heater arranged between each of the second both ends and the winding portion . The ceramic heater according to claim 1 , wherein at least the DC heat generation resistor reaches 600 ° C. or higher when energized . The ceramic heater according to claim 1 or 2 , wherein a voltage higher than that of the first end is applied to the second end .

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