JP7249270B2 - ceramic heater - Google Patents

Description

The present disclosure relates to ceramic heaters used in, for example, warm-water washing toilet seats, fan heaters, electric water heaters, 24-hour baths, soldering irons, hair irons, cogeneration systems, and the like.

As a ceramic heater having a heater body and a flange fitted on the heater body, for example, one described in Japanese Patent No. 6174821 (Patent Document 1 below) is known. The flange is cup-shaped with a concave portion that is recessed in the axial direction of the heater body, and the concave portion is filled with glass. The ceramic heater is integrated as a whole by joining the flange and the heater main body with glass.

Japanese Patent No. 6174821

It is preferable that the difference between the inner diameter of the flange and the outer diameter of the heater main body, for example, be equal to or less than a predetermined dimension in consideration of dripping prevention of the molten glass. However, the inner diameter of the flange may be determined by the configuration of the mating pipe connected to the flange, in which case the difference from the outer diameter of the heater body may be greater than 1 mm. If the difference from the outside diameter of the heater main body becomes large, there is a possibility that it will not be possible to prevent dripping of the molten glass. That is, when there are dimensional restrictions on the inner diameter of the flange, it has been difficult to perform the joining while suppressing dripping of the sealing material such as glass.

The ceramic heater of the present disclosure includes a ceramic round-bar-shaped or tubular heater main body, and a flange that is provided in a tubular shape around the axis of the heater main body and into which the heater main body is inserted. wherein the flange includes a sealing material reservoir portion having an opening on one side, and a connecting portion having an opening on the other side, the heater main body is arranged inside the sealing material reservoir and the connection part, the flange and the heater main body are joined by the sealing material filled in the sealing material reservoir, and the sealing At the other end of the stopper member, the gap between the inner peripheral surface of the fixing member and the outer peripheral surface of the heater body is narrower than the radial distance between the connecting portion and the outer peripheral surface of the heater body. A ceramic heater provided with a narrow width portion.

According to the present disclosure, when there are dimensional restrictions on the inner diameter of the flange, it is possible to perform the joining while suppressing dripping of the sealing material.

FIG. 1 is a front view of the ceramic heater of Embodiment 1. FIG. FIG. 2 is a sectional view showing the internal structure of the ceramic heater. 3 is a cross-sectional view showing an enlarged joint portion of the first flange of FIG. 2. FIG. FIG. 4 is a perspective view of the first flange. FIG. 5 is a plan view of the first flange. FIG. 6 is a perspective view showing how the ceramic sheet is wrapped around the outer peripheral surface of the ceramic tube and adhered. FIG. 7 is a perspective view showing how each flange and the heater main body are joined with glass. FIG. 8 is a cross-sectional view showing an enlarged joint portion of the first flange of the second embodiment. FIG. 9 is a cross-sectional view showing an enlarged joint portion of the first flange of the third embodiment.

[Description of Embodiments of the Present Disclosure]
First, the embodiments of the present disclosure are listed and described.
(1) The ceramic heater of the present disclosure includes a heater main body made of ceramic in the shape of a round bar or cylinder, and a flange that is cylindrically provided around the axis of the heater main body and into which the heater main body is inserted. , wherein the flange includes a sealing material reservoir portion having an opening on one side and a connection portion having an opening on the other side, The flange and the heater main body are joined by the sealing material filled in the sealing material reservoir in a state in which the heater main body is arranged inside the sealing material reservoir and the connection part. , at the other end of the sealing material, the gap between the inner peripheral surface of the sealing member and the outer peripheral surface of the heater main body is equal to the radial distance between the connecting portion and the outer peripheral surface of the heater main body. It is a ceramic heater provided with a narrower width portion.

When joining the flange and the heater main body, the molten sealing material is filled from the one-side opening into the sealing material reservoir, and the sealing material is cooled and hardened, thereby completing the bonding. Even if there is a large difference between the inner diameter of the flange and the outer diameter of the heater main body when filling, the gap between the inner peripheral surface of the narrow width portion and the outer peripheral surface of the heater main body is enough , the sealing material filled in the sealing material reservoir can be prevented from dripping to the other side.

(2) The flange has a large-diameter portion forming the sealing material reservoir portion, a small-diameter portion smaller in diameter than the large-diameter portion and forming the connection portion, and the small-diameter portion forming a step. It is preferable to have a connecting portion that connects the portion and the large diameter portion.
It is known that when the sealing material is cooled, one side of the sealing material tries to expand in diameter with the other side of the sealing material as a fulcrum, and a tensile stress is generated on one side of the sealing material. According to the above configuration, since the sealing material reservoir portion is formed of the large diameter portion, the tensile stress can be dispersed over a wider range than when the sealing material reservoir portion is formed of the small diameter portion. can. Therefore, cracks in the sealing material can be suppressed.

(3) It is preferable that a spacer that is supported by the flange with the heater main body inserted therein is arranged inside the flange, and that the narrow portion be the spacer.
When the narrow width portion is formed integrally with the flange, the flange is thick at the position of the narrow width portion and has a distorted shape, so stress is likely to occur during cooling of the sealing material. In addition, since the narrow width portion cannot be processed by press working, it is disadvantageous in terms of manufacturing cost. In this regard, since the narrow width portion is formed separately from the flange, the flange can be prevented from becoming distorted, and the narrow width portion can be manufactured by press working.

(4) The flange is preferably made of metal.
When the flange is made of metal, the flange can be formed by pressing a flat metal plate, so the manufacturing cost of the flange can be reduced.

(5) It is preferable that the thickness of the inner wall forming the sealing material reservoir is constant.
If the thickness of the inner wall forming the encapsulant reservoir is not constant, that is, if the shape of the encapsulant reservoir is distorted, stress is likely to occur during cooling of the encapsulant. In this regard, if the thickness of the inner wall forming the encapsulant reservoir is constant, stress is less likely to occur when the encapsulant is cooled, and cracking of the encapsulant can be avoided, for example.

[Details of Embodiment 1 of the Present Disclosure]
A specific example of the ceramic heater of the present disclosure will be described below with reference to the drawings. The present disclosure is not limited to these examples, but is indicated by the scope of the claims, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims.

<Overall configuration of ceramic heater>
The ceramic heater 11 of Embodiment 1 is a heater for heating liquids used for warm-water washing toilet seats, 24-hour baths, hand washing, cogeneration, and the like. As shown in FIGS. 1 and 2, the ceramic heater 11 includes a cylindrical ceramic heater main body 20, a metallic annular second flange 30 into which the heater main body 20 is inserted, and a second flange. a first flange 40 disposed below 30;

<Heater body>
The heater main body 20 is provided so as to have a cylindrical shape centered on the axis AX. The heater main body 20 includes a ceramic tube 21 and a ceramic layer 22 covering substantially the entire outer circumference of the ceramic tube 21 . Since the ceramic layer 22 does not completely cover the outer periphery of the ceramic tube 21, the outer peripheral surface 23 of the heater body 20 is formed with a groove portion 24 extending in the axial direction (direction parallel to the direction in which the axis AX extends). .

The ceramic tube 21 and the ceramic layer 22 forming the heater main body 20 are made of alumina, for example. The thermal expansion coefficient of alumina is in the range of 50×10 ⁻⁷ /K to 90×10 ⁻⁷ /K, and in the present embodiment, it is 70×10 ⁻⁷ /K (30° C. to 380° C.). It's becoming

As shown in FIG. 6, a heater pattern layer 25 having a meandering pattern and a pair of internal terminals 26 are formed on or inside the ceramic layer 22 (the surface facing the ceramic tube 21). These internal terminals 26 are electrically connected to external terminals 27 at the ends of the outer peripheral surface of the ceramic layer 22 via via conductors (not shown) or the like.

<Second flange>
The second flange 30 is, for example, an annular member made of metal such as stainless steel, and as shown in FIG. 2, is provided in a cylindrical shape around the axis AX. The second flange 30 is formed in a concave shape (cup shape) by, for example, pushing out the center portion of a metal plate material downward by press working. Specifically, the second flange 30 has a large diameter portion 31 that opens upward, and a small diameter portion 32 that is arranged below the large diameter portion 31 and has a smaller diameter than the large diameter portion 31, and has a stepped shape. A connection portion 33 that connects the large diameter portion 31 and the small diameter portion 32 is provided. A hole portion 34 is formed in the central portion of the bottom surface of the small diameter portion 32 . The hole portion 34 has a form vertically penetrating through the bottom surface of the small diameter portion 32 .

The thermal expansion coefficient of the metal forming the second flange 30 is a value within the range of 100×10 ⁻⁷ /K to 200×10 ⁻⁷ /K. For example, when the second flange 30 is made of SUS304 (main components are Fe, Ni, and Cr), its thermal expansion coefficient is 178×10 ⁻⁷ /K (30° C. to 380° C.), and SUS430 ( When the main component is Fe, Cr), its thermal expansion coefficient is 110×10 ⁻⁷ /K (30° C. to 380° C.).

The inside of the small diameter portion 32 of the second flange 30 is a glass reservoir portion 37 filled with glass 36 . The second flange 30 and the heater main body 20 are integrally joined by glass 36 . As _the glass 36, for example, _{Na2O.Al2O3.B2O3.SiO2} -based glass, so _{-called Al2O3.B2O3.SiO2- based glass ( borosilicate glass )} is _{used .} It is The coefficient of thermal expansion of the glass 36 is, for example, a value within the range of 50×10 ⁻⁷ /K to 90×10 ⁻⁷ /K (30° C. to 380° C.), and in this embodiment it is 62×10 ⁻⁷ / K (30° C. to 380° C.).

A narrow gap of, for example, about 0.1 mm to 1.0 mm exists between the hole edge of the hole portion 34 and the outer peripheral surface 23 of the heater main body 20. In the present embodiment, the narrow gap has a dimension of 0.3 mm. It is set to about 0.5 mm.

<First flange>
The first flange 40 is, for example, an annular member made of metal such as stainless steel, and as shown in FIG. 2, is provided in a cylindrical shape around the axis AX. The first flange 40 is manufactured, for example, by pressing a base metal material downward to form a stepped, bottomed tubular shape, and then punching out the bottom surface. The first flange 40 as a whole has a form penetrating in the vertical direction. It is composed of a small diameter portion 42 and a connection portion 43 that connects the large diameter portion 41 and the small diameter portion 42 in a stepped manner.

The large diameter portion 41 has an upper opening 44 that opens upward, and the small diameter portion 42 has a lower opening 45 that opens downward. The small-diameter portion 42 constitutes a connecting portion 49 connected to a mating pipe (not shown). The mating pipe is a pipe for supplying water, and the water entering the heater main body 20 through the lower opening 45 of the first flange 40 from the mating pipe is heated.

The first flange 40 is fitted around the lower end of the heater body 20 . The lower end of the heater main body 20 is positioned at the upper end of the small diameter portion 42 of the first flange 40, and the heater main body 20 is arranged to penetrate the large diameter portion 41 and the connecting portion 43 in the vertical direction. A glass reservoir 47 filled with glass 46 is provided inside the first flange 40 . The glass pool portion 47 is a space filled with the glass 46 , and more specifically, the outer peripheral surface of the heater main body 20 and the inner peripheral surface of the first flange 40 from the large diameter portion 41 to the connecting portion 43 . and a spacer 50 to be described later.

The first flange 40 and the heater main body 20 are integrally joined by the glass 46 while the heater main body 20 is arranged inside the glass reservoir portion 37 and the connecting portion 49 . As _{the glass} 46, for example, _{Na2O.Al2O3.B2O3.SiO2} -based glass, _{so -called Al2O3.B2O3.SiO2- based glass ( borosilicate} glass) is _{used .} It is The thermal expansion coefficient of the glass 46 is, for example, a value within the range of 50×10 ⁻⁷ /K to 90×10 ⁻⁷ /K (30° C. to 380° C.), and in this embodiment it is 62×10 ⁻⁷ / K (30° C. to 380° C.).

The thickness T of the inner wall formed by the first flange 40 among the inner walls forming the glass pool portion 47 is constant. This thickness T is, for example, 0.8±0.1 mm. When the thickness T is constant, stress is less likely to occur during cooling of the glass 46, and cracking of the glass 46 can be prevented.

A spacer 50 is formed at the lower end of the inner wall forming the glass pool portion 47 . As shown in FIGS. 4 and 5, the spacer 50 includes a cylindrical portion 51 extending vertically, and a collar portion 52 projecting radially outward from the upper edge of the cylindrical portion 51 . configured as follows. The inner peripheral surface of the tubular portion 51 is arranged along the outer peripheral surface of the heater main body 20 as shown in FIG.

The outer diameter of the heater main body 20 is, for example, 10.4±0.3 mm, and the inner diameter of the small diameter portion 42 of the first flange 40 is, for example, 13.05±0.05 mm. Therefore, the radial distance L between the outer peripheral surface of the heater main body 20 and the inner peripheral surface of the small diameter portion 42 of the first flange 40 is 1.15 to 1.5 mm (one side). If the distance L is greater than 1 mm, the glass 46 may hang below the first flange 40 . Therefore, in this embodiment, the spacer 50 is arranged in the gap G to suppress the drooping of the glass 46 .

The spacer 50 is configured separately from the first flange 40 , and is arranged on the first flange 40 by being inserted into the glass reservoir 47 from the upper opening 44 and hooking the flange 52 to the connecting portion 43 . Most of the gap G is closed by the spacer 50, leaving only a narrow gap S1 between the outer peripheral surface of the heater main body 20 and the inner peripheral surface of the tubular portion 51 of the spacer 50. FIG. The dimension of this narrow gap S1 is, for example, 0 to 0.35 mm (one side). Moreover, since the flange portion 52 is arranged in contact with the upper surface of the connecting portion 43 , there is almost no gap between the flange portion 52 and the upper surface of the connecting portion 43 . At the lower end of the glass 46, the spacer 50 is arranged so that the narrow gap S1 is narrower than the radial distance L1. This can prevent the glass 46 filled in the glass reservoir 47 from sagging below the first flange 40 . In order to suppress dripping of the glass 46, it is preferable to set the dimension of the narrow gap S1 to 0.5 mm or less (one side).

<Ceramic heater manufacturing method>
Next, a method of manufacturing the ceramic heater 11 will be described with reference to FIGS. 6 and 7. FIG.
First, as shown in FIG. 6, a cylindrical alumina ceramic tube 21 is calcined. Separately from this, a high melting point metal such as tungsten is printed on the surface of the alumina ceramic sheet 60 or inside the laminated sheets. As a result, a pattern 61 that will later become the heater pattern layer 25, the internal terminals 26, and the external terminals 27 is formed.

Next, ceramic paste (alumina paste) is applied to one side surface of the ceramic sheet 60, and as shown in the left diagram of FIG. do. After that, the external terminals 27 are plated with nickel to form the heater main body 20 . As a result, as shown in the right diagram of FIG. 6, only the external terminals 27 are exposed to the outside.

Next, as shown in the left diagram of FIG. 7, the first flange 40 and the second flange 30 are fitted onto the heater main body 20 at predetermined height positions, and in this state, the flanges 30, 40 and the heater main body 20 are attached. It is supported by a jig (not shown). When fitting the first flange 40 to the heater main body 20, the collar portion 52 of the spacer 50 is placed on the upper surface of the connecting portion 43 of the first flange 40 in advance, and from this state, the cylindrical portion of the spacer 50 is 51 is fitted around the lower end of the heater body 20 . Thereby, the gap G formed between the outer peripheral surface of the heater main body 20 and the inner peripheral surface of the first flange 40 is almost closed by the spacer 50 .

Next, a glass material made of borosilicate glass is press-molded into a ring shape and calcined at 640° C. for 30 minutes to prepare calcined glass materials 38 and 48 in advance. 2, ring-shaped calcined glass members 38, 48 are placed in the glass pools 37, 47 between the heater main body 20 and the flanges 30, 40, respectively.

Next, this state is put into a continuous furnace for firing, and the heater main body 20 and each of the flanges 30 and 40 are attached with glass. Specifically, the calcined glass materials 38 and 48 are melted by heating at the welding temperature (1015° C.) for a predetermined time in a reducing atmosphere (for example, N ₂ +5% H ₂ ) in the continuous furnace. After that, the calcined glass materials 38 and 48 are cooled to room temperature (for example, 25° C.) and solidified, so that the heater main body 20 and each flange 30 are connected to each other through the glasses 36 and 46 as shown in the right diagram of FIG. , 40 are welded and fixed to complete the ceramic heater 11 .

<Effect of Embodiment 1>
According to the ceramic heater 11 of the present embodiment, when the first flange 40 and the heater main body 20 are joined together, the molten glass 46 is filled from the upper opening 44 into the glass reservoir 47, and the glass 46 cools and hardens. to complete the joining. Even when the difference between the inner diameter of the first flange 40 and the outer diameter of the heater main body 20 is large at the time of filling, the narrow gap S1 between the inner peripheral surface of the spacer 50 and the outer peripheral surface of the heater main body 20 is the connecting portion. Since it is narrower than the radial distance L between 49 and the outer peripheral surface of the heater main body 20, the glass 46 filled in the glass reservoir 47 can be prevented from dripping downward.

The first flange 40 includes a large-diameter portion 41 forming a glass reservoir portion 47, a small-diameter portion 42 having a smaller diameter than the large-diameter portion 41 and forming a connection portion 49, and a small-diameter portion 42 having a stepped shape. and a connecting portion 43 that connects the large-diameter portion 41 . It is known that when the glass 46 is cooled, the upper side of the glass 46 tries to expand in diameter with the lower side of the glass 46 as a fulcrum, and a tensile stress is generated in the upper side of the glass 46 . According to the above configuration, since the glass pool portion 47 is composed of the large-diameter portion 41, the tensile stress can be dispersed over a wider range than when the glass pool portion 47 is composed of the small-diameter portion 42. can. Therefore, cracks in the glass 46 can be suppressed.

A spacer 50 that is supported by the first flange 40 with the heater main body 20 inserted therein is preferably arranged inside the first flange 40 . When the narrow width portion is formed integrally with the first flange 40 instead of the spacer 50, the first flange 40 is thick at the position of the narrow width portion and has a distorted shape, so stress is likely to occur when the glass is cooled. . In addition, since the narrow width portion cannot be processed by press working, it is disadvantageous in terms of manufacturing cost. In this regard, since the spacer 50 as the narrow width portion is configured separately from the first flange 40, the first flange 40 can be prevented from being distorted, and the spacer 50 can be manufactured by pressing.

Preferably, the first flange 40 is made of metal. When the first flange 40 is made of metal, the manufacturing cost of the first flange 40 can be reduced because the first flange 40 can be formed by pressing a flat metal plate.

It is preferable that the thickness T of the inner wall forming the glass pool portion 47 is constant. If the thickness T of the inner wall forming the glass reservoir 47 is not constant, that is, if the shape of the glass reservoir 47 is distorted, stress is likely to occur when the glass 46 is cooled. In this regard, if the thickness T of the inner wall forming the glass pool portion 47 is constant, stress is less likely to occur during cooling of the glass 46, and breakage of the glass 46, for example, can be avoided.

[Details of Embodiment 2 of the Present Disclosure]
Next, Embodiment 2 will be described with reference to FIG. The ceramic heater 12 of the second embodiment is obtained by partially changing the configuration of the first flange 40 of the ceramic heater 11 of the first embodiment, and the rest of the configuration is the same as that of the first embodiment. omitted. Also, the same reference numerals as in the first embodiment are used for the same configurations as in the first embodiment.

The first flange 70 of the present embodiment has a large-diameter portion 71 that opens upward, and a small-diameter portion 72 that is arranged below the large-diameter portion 71 and has a smaller diameter than the large-diameter portion 71, forming a stepped shape. A connection portion 73 that connects the large diameter portion 71 and the small diameter portion 72 is provided. The large diameter portion 71 has an upper opening 74 that opens upward, and the small diameter portion 72 has a lower opening 75 that opens downward.

The small-diameter portion 72 constitutes a connecting portion 79 connected to a mating pipe (not shown). The mating pipe is a pipe for supplying water, and water entering the heater body 20 through the first flange 70 from the mating pipe is heated.

A glass reservoir 77 filled with glass 76 is provided inside the first flange 70 . The glass pool portion 77 is a space filled with glass 76. More specifically, the outer peripheral surface of the heater main body 20 and the inner peripheral surface of the first flange 70 from the large diameter portion 71 to the connecting portion 73 , and a narrow portion 78 described below.

A narrow portion 78 is provided at the lower end of the glass 76 . The narrow portion 78 is provided on the inner peripheral side of the upper end portion of the small diameter portion 72 . The narrow portion 78 is formed integrally with the small-diameter portion 72, protrudes radially inward from the inner peripheral surface of the small-diameter portion 72, and is provided in an annular shape about the axis AX. The inner peripheral surface of the narrow portion 78 extends vertically along the outer peripheral surface of the heater main body 20 .

A narrow gap S2 is formed between the outer peripheral surface of the heater main body 20 and the inner peripheral surface of the narrow portion 78 . The dimension of this narrow gap S2 is, for example, 0 to 0.35 mm (one side). This can prevent the glass 76 filled in the glass reservoir 77 from sagging below the first flange 70 .

[Details of Embodiment 3 of the Present Disclosure]
Next, Embodiment 3 will be described with reference to FIG. The ceramic heater 13 of the third embodiment is obtained by partially changing the configuration of the first flange 40 of the ceramic heater 11 of the first embodiment, and the rest of the configuration is the same as that of the first embodiment. omitted. Also, the same reference numerals as in the first embodiment are used for the same configurations as in the first embodiment.

Unlike the first flange 40 of Embodiment 1, the first flange 80 of this embodiment does not include a large diameter portion and a connecting portion, and is configured only by a small diameter portion 82 . Therefore, the first flange 80 has a cylindrical shape as a whole. The small diameter portion 82 has an upper opening 84 that opens upward and a lower opening 85 that opens downward.

The lower end side of the small diameter portion 82 constitutes a connecting portion 89 connected to a mating pipe (not shown). The mating pipe is a pipe for supplying water, and the water entering the inside of the heater main body 20 through the bottom opening 85 from the mating pipe is heated.

A glass reservoir portion 87 filled with glass 86 is provided inside the upper end side of the small diameter portion 82 . The glass reservoir portion 87 is a space filled with the glass 86, and includes the outer peripheral surface of the heater main body 20, the inner peripheral surface of the small diameter portion 82 of the first flange 80, and the upper surface of the spacer 90 described below. is a space surrounded by

A gap G is formed between the outer peripheral surface of the lower end portion of the heater main body 20 and the inner peripheral surface of the small diameter portion 82, and the spacer 90 is arranged in the gap G. As shown in FIG. The spacer 90 of this embodiment is configured separately from the small diameter portion 82 and arranged at the lower end portion of the glass 86 . Although the outer diameter of the spacer 90 is smaller than the outer diameter of the spacer 50 of the first embodiment, the inner diameter of the spacer 90 is the same as the inner diameter of the spacer 50 of the first embodiment.

A narrow gap S3 is formed between the outer peripheral surface of the heater main body 20 and the inner peripheral surface of the spacer 90 . The dimension of this narrow gap S3 is, for example, 0 to 0.35 mm (one side). The spacer 90 is held by, for example, press-fitting to the first flange 80 , and the outer peripheral edge portion 91 of the spacer 90 is in contact with the inner peripheral surface of the small diameter portion 82 over the entire circumference. As a result, the glass 86 filled in the glass reservoir 87 can be prevented from sagging below the first flange 90 .

<Other embodiments>
(1) In Embodiments 1 to 3, the cylindrical heater main body 20 is exemplified.

(2) In Embodiments 1 to 3, glass is used as the sealing material, but an epoxy-based sealing material, a ceramic-based sealing material, or the like may be used.

(3) Although the spacer 50 is arranged in the connecting portion 43 in the first embodiment, the spacer 90 in the third embodiment may be used and held by the small diameter portion 42 .

(4) Although the first flange is made of metal in Embodiments 1 to 3, it may be made of ceramic.

(5) In Embodiments 1 and 3, the tubular spacers 50 and 90 that are seamlessly connected in the circumferential direction when viewed from above are used. may be used.

Reference Signs List 11 Ceramic heater 20 Heater body 21 Ceramic tube 22 Ceramic layer 23 Outer peripheral surface 24 Groove 25 Heater pattern layer 26 Internal terminal 27 External terminal 30 Second flange 31 Large-diameter portion 32 Small-diameter portion 33 Connection portion 34 Hole portion 36 Glass 37 Glass pool portion 38 Tempered glass material 40 First flange (flange) 41 Large diameter Part, 42... Small diameter part, 43... Connecting part, 44... Upper opening (one side opening), 45... Lower opening (other side opening), 46... Glass (sealing material), 47... Glass reservoir Part (sealing material reservoir) 48 Tempered glass material 49 Connection part 50 Spacer (narrow width part) 51 Cylindrical part 52 Flange 60 Ceramic sheet 61 Pattern 70 First flange (flange) 72 large diameter portion 73 small diameter portion 73 connecting portion 74 upper opening (one side opening) 75 lower opening (other side opening) 76 Glass (sealing material) 77 Glass pool portion 78 Narrow width portion 79 Connection portion 80 First flange (flange) 82 Small diameter portion 84 Upper opening 85 Lower opening 86...Glass 87...Glass reservoir 89...Connecting part 90...Spacer (narrow part) 91...Outer peripheral edge AX...Axis line G...Gap L...Distance S1...Narrow gap S2...Narrow gap S3 … Narrow clearance, T … Thickness

Claims (5)

a ceramic round-bar-shaped or cylindrical heater main body;
A ceramic heater comprising a flange that is cylindrically provided around the axis of the heater body and into which the heater body is inserted,
The flange includes a sealing material reservoir portion having a one-side opening that opens to one side, and a connection portion having a second-side opening that opens to the other side,
The flange and the heater main body are joined by the sealing material filled in the sealing material reservoir in a state in which the heater main body is arranged inside the sealing material reservoir and the connection part. ,
At the other end of the sealing material, the gap between the inner peripheral surface of the sealing member itself and the outer peripheral surface of the heater main body is larger than the radial distance between the connecting portion and the outer peripheral surface of the heater main body. A ceramic heater having a narrow narrow portion. The flange includes a large-diameter portion forming the sealing material reservoir portion, a small-diameter portion having a diameter smaller than that of the large-diameter portion and forming the connection portion, and a stepped portion formed between the small-diameter portion and the connection portion. 2. The ceramic heater according to claim 1, further comprising a connecting portion that connects the large diameter portion. A spacer is arranged inside the flange and is supported by the flange with the heater main body inserted therein,
3. The ceramic heater according to claim 1, wherein said narrow portion is said spacer. 4. The ceramic heater according to any one of claims 1 to 3, wherein said flange is made of metal. 5. The ceramic heater according to any one of claims 1 to 4, wherein the inner wall forming the sealing material reservoir has a constant thickness.

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