JP3905205B2 - Saya support structure and continuous heat treatment method used in continuous heat treatment furnace - Google Patents

Description

【００１７】
表１及び図５から明らかなように、コマ２７の高さ即ち台板２６からサヤ２０の底板部材２１までの高さが３０ｍｍ以上になると、クラック発生迄の使用回数が飛躍的に伸び、特に３５ｍｍ以上になるとその伸びが顕著になった。また、高さが３０ｍｍ以上特に３５ｍｍ以上になると上段のサヤ２０と下段のサヤ２０との温度差が小さくなるため、両サヤ２０、２０に収納されたセラミック成形体の焼成条件が略同一になり、焼成後のセラミック成形体の製品バラツキが小さくなった。なお、サヤ２０は、底板部材２１及び枠部材２４とも粉末アルミナセラミックを１６００〜１７００℃で焼成したものを用いたが、その粉末粒度は荒い方がクラック発生までの使用回数が伸びるため好ましい結果が得られた。また、上段のサヤ２０は１５回以上繰り返し使用してもクラックは発生しなかった。
【００１８】
以上のように、コマ２７の高さを３０ｍｍ以上にすれば、サヤ２０の寿命が長くなり繰り返し使用できる回数が増えるため、サヤ２０にかかるコストが低減され、ひいては製品であるセラミック成形体の製造コストが低減される。また、上段と下段の温度差が小さくなるため製品バラツキが小さくなり、製品の品質が安定化する。
【図面の簡単な説明】
【図１】 サヤ搭載台車の説明図（図３のＡ−Ａ断面図）である。
【図２】 サヤの組立斜視図である。
【図３】 連続熱処理炉の説明図である。
【図４】 コマの配置図である。
【図５】 試験例１〜５のクラック発生迄の使用回数を示すグラフである。
【符号の説明】
１〜７・・・第１〜第７ゾーン、１０・・・連続熱処理炉、２０・・・サヤ、２１・・・底板部材、２２・・・突起、２３・・・切欠、２４・・・枠部材、２５・・・窓部、２６・・・台板、２７・・・コマ、３０・・・サヤ搭載台車。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a ceramic sheath and a continuous heat treatment method used in a continuous heat treatment furnace that performs calcination of powder and the like.
[0002]
[Prior art]
As shown in FIGS. 1 and 2, a sheath 20 used in a continuous heat treatment furnace 10 that performs calcination of powder or the like includes an alumina ceramic bottom plate member 21 having substantially L-shaped protrusions 22 at four corners, and each protrusion 22. A frame member 24 made of alumina ceramic having a substantially L-shaped notch 23 that fits in, and a window portion 25 is provided on the upper surface of the frame member 24 to ensure the circulation of air between the outside and the inside. It has been. A plurality of ceramic green compacts used for, for example, electronic components, gas sensor elements or plugs are arranged in the sheath 20, and the sheath 20 is placed on a ceramic base plate 26 via a frame 27. It piles up on the stage and it becomes the Saya carrying cart 30.
[0003]
On the other hand, as shown in FIG. 3, the continuous heat treatment furnace 10 is provided with a plurality of heat treatment zones (first zone 1 to seventh zone 7) from the inlet to the outlet. 7 is maintained at the temperature shown in FIG. The temperature is measured with a thermocouple.
[0004]
Then, by pushing the side surface of the base plate 26 of the bogie 30 with a pusher into the inlet of the continuous heat treatment furnace 10 over about 35 minutes, the bogie 30 enters the first zone 1 of the continuous heat treatment furnace 10, and then Then, another saddle-mounted carriage 30 is pushed in with the pusher in the same manner, and this operation is sequentially repeated. As a result, the bogie 30 mounted on the sheath 30 is pushed and moved in the so-called “place” type in the continuous heat treatment furnace 10, proceeds from the first zone 1 to the seventh zone 7, and finally from the seventh zone 7 to the outside of the furnace. Extruded and quenched here.
[0005]
As described above, when the sheath mounted carriage 30 is pushed out of the furnace from the seventh zone 7 (1490 ° C.), cracks may occur in the bottom plate member 21 of the lower sheath 20 after repeated use 2-3 times. . Since the sheath 20 after passing through the continuous heat treatment furnace 10 is moved to the next process (for example, an inspection process) while the ceramic molded body is accommodated therein, a crack is generated in the bottom plate member 21 of the sheath 20. There was a problem that the ceramic molded body that had been cracked and dropped was dropped. For this reason, when a crack occurs in the bottom plate member 21, the bottom plate member 21 is discarded and replaced with a new one.
[0006]
[Problems to be solved by the invention]
However, if the frequency of replacing the bottom plate member 21 of the sheath 20 is high, there is a problem that the cost for the sheath 20 increases. For this reason, it has been desired to suppress the occurrence of cracks in the sheath 20 and to extend the life of the sheath 20, that is, to increase the number of times it can be used repeatedly.
[0007]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a sheath support structure that suppresses occurrence of cracks in the sheath when used in a continuous heat treatment furnace, and such a continuous heat treatment method.
[0008]
Means for Solving the Problems, Embodiments of the Invention, and Effects of the Invention
In order to solve the above-mentioned problems, the present invention provides a base plate that can be moved in a continuous heat treatment furnace, a ceramic sheath for housing an unfired ceramic molded body, and a space for placing the ceramic sheath on the base plate. a sheath support structure for use in the continuous heat treatment furnace and a support member for supporting through, the ceramic sheath, said the support member is supported at a height of more than 30mm from the base plate Rutotomoni, after firing The continuous firing furnace maintained at the firing temperature is suddenly taken out of the continuous firing furnace .
[0009]
In the present invention, a ceramic sheath containing an unfired ceramic molded body is placed in a continuous heat treatment furnace in a state where the continuous heat treatment furnace is supported on a movable base plate at a height of 30 mm or more via a space. A fired ceramic molded body is fired. After firing, the ceramic sheath is suddenly removed from the continuous firing furnace maintained at the firing temperature.
According to the present invention, since the ceramic sheath is supported at a height of 30 mm or more from the base plate, the number of times of use until cracks occur in the sheath (especially the bottom plate) (how many times it can be passed through a continuous heat treatment furnace) ) Has increased dramatically. The reason is not clear, between the ceramic sheath and the base plate for between sky becomes wide, the heat gradient of the ceramic sheath is loose (ie the whole of the temperature variation is reduced), due to thermal shock cracks The occurrence is considered to be suppressed. The upper limit is not particularly defined if the height of the sheath from the base plate is 30 mm or more, but it is preferably 100 mm or less in consideration of the size of the normal continuous heat treatment furnace and the balance when the sheath is supported. .
[0010]
The ceramic sheath is produced by firing at 1600 to 1700 ° C., for example. However, the coarser the powder particle size before firing, the less the heat shrinks, so that cracks are less likely to occur. However, rather than changing the powder particle size, it is preferable to support the sheath at a height of 30 mm or more from the base plate because the effect of suppressing the occurrence of cracks is high.
[0011]
In the present invention, it is preferable to stack ceramic sheaths in a plurality of stages. Ceramic sheath to a ceramic is a ceramic molded body unfired is to be passed through a continuous heat treatment furnace in a state in which a plurality accommodated, if supported in a state of stacked this sheath in a plurality of stages, which can be fired in correspondingly once The number of compacts increases and mass production efficiency improves. In addition, since the lower sheath is supported at a height of 30 mm or more from the base plate, the temperature difference between the upper sheath and the lower sheath is reduced, the firing conditions are made substantially uniform, and the fired ceramic molding Body product variation is reduced.
[0012]
In addition, if the continuous heat treatment furnace is a type that is rapidly cooled from the firing temperature to room temperature after firing, cracks are likely to occur originally, but by supporting the sheath at a height of 30 mm or more from the base plate, Even in this case, the generation of cracks can be effectively suppressed. Examples of this type of continuous heat treatment furnace include those that suddenly go out of the high temperature zone and are exposed to room temperature at room temperature, and those that have a short time to pass through the continuous heat treatment furnace.
[0013]
【Example】
[Test Examples 1 to 8]
The continuous heat treatment furnace and the sheath used therefor were the same as those shown in FIGS. The continuous heat treatment furnace 10 has a width of 320 mm, a height of 375 mm, and a total length of 3600 mm. The bottom plate member 21 of the sheath 20 has a length of 300 × width of 300 × height of 20 mm, and the frame member 24 has a length of 300 × width of 300 × height of 100 mm. Things were used.
[0014]
Further, in the same manner as in the prior art, a plurality of ceramic green compacts are arranged in the sheath 20 and the height corresponding to Test Examples 1 to 6 is set on the base plate 26 made of alumina ceramic (see Table 1). This sheath 20 was stacked in two stages through a frame 27 (length 50 × width 50 × height 20 to 45 mm) as a support member, and a sheath-mounted carriage 30 was obtained. At this time, the frame 27 is arranged eight on the base plate 26 as shown in FIG. 4, provided between the sky between the sheath 20 and the base plate 26. Then, the side surface of the base plate 26 of the Saya-equipped carriage 30 is pushed into the first zone 1 of the continuous heat treatment furnace 10 by pushing it in with a pusher for about 35 minutes, and then another Saya-equipped carriage 30 is similarly made with the pusher. By pushing in and repeating this operation in sequence, the Saya-equipped carriage 30 is pushed forward in a so-called “Tokoro” style, moved from the first zone 1 to the seventh zone 7, and finally pushed out of the seventh zone 7 to the outside of the furnace. , Cooled rapidly.
[0015]
And it investigated about how many times it can be repeatedly used until the crack occurs in the baseplate member 21 about the lower sheath 20 of the test examples 1-8. Further, the temperature difference between the upper sheath 20 and the lower sheath 20 was investigated. The results are shown in Table 1 and FIG. Test example 2 is a conventional example, and test examples 4 to 8 correspond to examples of the present invention.
[0016]
[Table 1]

[0017]
As is apparent from Table 1 and FIG. 5, when the height of the top 27, that is, the height from the base plate 26 to the bottom plate member 21 of the sheath 20 is 30 mm or more, the number of times of use until the occurrence of cracking increases dramatically. The elongation became remarkable when it became 35 mm or more. In addition, when the height is 30 mm or more, particularly 35 mm or more, the temperature difference between the upper sheath 20 and the lower sheath 20 is reduced, so that the firing conditions of the ceramic molded bodies housed in both the sheaths 20 and 20 are substantially the same. The product variation of the ceramic molded body after firing was reduced. In addition, although the bottom plate member 21 and the frame member 24 used the thing which baked the powder alumina ceramic at 1600-1700 degreeC, the Saya 20 used the preferable result because the one where the powder particle size is rough increases the number of times of use until crack generation. Obtained. In addition, the upper sheath 20 did not crack even after repeated use 15 times or more.
[0018]
As described above, if the height of the top 27 is set to 30 mm or more, the life of the sheath 20 becomes longer and the number of times it can be used repeatedly increases, so the cost for the sheath 20 is reduced, and as a result, the production of a ceramic molded body as a product is achieved. Cost is reduced. In addition, since the temperature difference between the upper and lower stages is reduced, the product variation is reduced and the product quality is stabilized.
[Brief description of the drawings]
FIG. 1 is an explanatory view (a cross-sectional view taken along the line AA in FIG. 3) of a carriage equipped with a sheath.
FIG. 2 is an assembled perspective view of a sheath.
FIG. 3 is an explanatory diagram of a continuous heat treatment furnace.
FIG. 4 is a layout diagram of frames.
FIG. 5 is a graph showing the number of times of use until occurrence of a crack in Test Examples 1 to 5.
[Explanation of symbols]
1-7 ... 1st-7th zones, 10 ... Continuous heat treatment furnace, 20 ... Saya, 21 ... Bottom plate member, 22 ... Projection, 23 ... Notch, 24 ... Frame member, 25... Window, 26 .. base plate, 27 .. top, 30.

Claims (6)

A base plate movable in a continuous heat treatment furnace;
A ceramic sheath for storing the unfired ceramic molded body;
A support member for supporting the ceramic sheath on the base plate via a space, and a support member for use in a continuous heat treatment furnace,
The ceramic sheath is said is supported by the base plate from above 30mm height by the support member Rutotomoni are those issued suddenly continuous firing furnace out from said continuous firing furnace maintained at the baking temperature after firing Saya support structure characterized by 2. The sheath support structure according to claim 1, wherein the ceramic sheaths are stacked in a plurality of stages.   The sheath support structure according to claim 1 or 2, wherein the continuous heat treatment furnace is of a type that is rapidly cooled from the firing temperature to room temperature after firing. The ceramic sheath housing the ceramic body unfired while supporting above height 30mm through space on a movable base plate a continuous heat treatment furnace, unfired ceramic placed in the continuous firing furnace A continuous heat treatment method characterized by firing the molded body, and after firing, the ceramic sheath is taken out of the continuous firing furnace suddenly from the continuous firing furnace maintained at a firing temperature . The continuous heat treatment method according to claim 4, wherein the ceramic sheath is supported in a state of being stacked in a plurality of stages. 6. The continuous heat treatment method according to claim 4, wherein the continuous heat treatment furnace is rapidly cooled from the firing temperature to room temperature after firing.

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