JP2004347208A - Electric furnace for ceramic art - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric furnace for ceramic art capable of performing an optimum drying in a short time without leading to a failure by insufficient drying in a drying process, and significantly reducing the time to baking by enabling the immediate drying of a handiwork molded of clay in a specified condition within the furnace. <P>SOLUTION: This electric furnace for ceramic art has a drying pattern for drying a handiwork put in the furnace over time separately from a plurality of baking patterns corresponding to biscuit firing and main baking. In the drying pattern, the handiwork molded of clay is immediately put in the furnace, and the furnace internal temperature is gradually raised to a predetermined drying temperature which does not reach the baking over time. According to this, the whole handiwork can be dried uniformly. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electric furnace for pottery, which fires a work housed in a furnace based on a predetermined firing pattern.
[0002]
[Prior art]
As a conventional electric furnace for pottery, for example, one in which a plurality of types of firing patterns are prepared for adapting to various works is known (for example, see Patent Document 1). The author can select a firing pattern suitable for the work to be fired from a plurality of types. During firing of the work, the amount of heat to be supplied into the furnace is determined based on the selected firing pattern. Further, the selected firing pattern can be displayed by the display means, and even if the firing is interrupted, the firing can be easily performed again.
[0003]
Before firing a work in such an electric furnace for pottery, in general pottery, it is necessary to form clay and allow it to dry naturally in a shaded and well-ventilated place for about one week to 10 days. was there. In addition, such a dried product is heated relatively rapidly at 40 ° C./h or 60 ° C./h to a firing temperature of 200 ° C. or 400 ° C., and the temperature inside the furnace is further dried before firing. Is also known (for example, refer to Patent Document 2). "Drying" in such a device is different from the above-mentioned concept of drying in general ceramics.
[0004]
[Patent Document 1]
JP 2001-31590 A
[Patent Document 2]
Registered Utility Model No. 3038863
[0005]
[Problems to be solved by the invention]
However, according to the above-mentioned conventional technology, the work is naturally dried for about one week to 10 days until the work is fired in the furnace after the work is formed from clay, so it takes a very long time to complete the work. There was a problem that it took. In addition, for amateurs, the drying of the work does not proceed evenly due to the effect of wind and the change in humidity in natural drying, and the unevenness of the drying state occurs, etc. It was difficult to judge the results, and if it was fired with insufficient drying, there were cases where defects such as cracks, cracks, and warpage occurred in the work.
[0006]
In addition, in order to shorten the time until firing after forming the work from clay, `` drying '' in the firing furnace control device, blowing of hot air by a dryer, or rapid drying of the work by sun drying, etc. If this is done, only the surface of the work is dried, and the work is locally shrunk, thereby causing a problem that cracks, cracks, warpage, and the like are likely to occur.
[0007]
The present invention has been made in view of the problems of the prior art as described above, and enables a work formed from clay to be immediately dried under special conditions in a furnace, and in a drying step. An object of the present invention is to provide an electric furnace for pottery which can perform optimal drying in a short time without causing a failure due to insufficient drying or the like, and can greatly reduce a time until firing. .
[0008]
[Means for Solving the Problems]
The gist of the present invention to achieve the above-described object lies in the following inventions.
[1] An electric furnace for ceramics (10) for firing a work contained in a furnace based on a predetermined firing pattern (P1),
In addition to the firing pattern (P1), a drying pattern (P0) for drying the work inside the furnace over time is provided,
In the drying pattern (P0), the inside of the furnace, in which a work formed from clay is immediately stored, is gradually heated to a predetermined drying temperature which does not lead to firing, and the viscosity of water in the clay is reduced. An electric furnace for pottery (10), characterized in that the whole work is uniformly dried by increasing the water vapor pressure in the clay.
[0009]
[2] The electric furnace for ceramics according to [1], wherein the predetermined drying temperature is set to an arbitrary temperature from 60 ° C to 80 ° C.
[0010]
[3] The electric furnace for ceramics according to [1] or [2], wherein in the drying pattern (P0), the humidity inside the furnace is maintained at around 80%.
[0011]
[4] The pottery electric furnace (10) according to [1], [2] or [3], wherein the drying pattern (P0) includes a plurality of steps.
[0012]
[5] The dry pattern (P0) is characterized in that a plurality of different patterns are prepared according to the properties of clay or the shape and size of the work [1], [2], [3]. ] Or the electric furnace for ceramics according to [4] (10).
[0013]
[6] After completion of the drying pattern (P0), a composite pattern is provided, which can be continuously transferred to the firing pattern (P1) as it is [1], [2], [3], [4] ] Or the electric furnace for ceramics according to [5] (10).
[0014]
[7] The electric furnace for ceramics according to [6], wherein the firing pattern (P1) in the composite pattern is a pattern corresponding to unsintering among a plurality of firing patterns (P1).
[0015]
Next, the operation of the present invention will be described.
In the ceramic electric furnace (10) according to the above [1], apart from the firing pattern (P1) corresponding to unglazing or main firing, a drying pattern (P0) for drying a work placed in the furnace over time. It has. In this drying pattern (P0), a work formed from clay is placed in a furnace as soon as possible, and the inside of the furnace is gradually raised to a predetermined drying temperature that does not lead to firing, so that the entire work is obtained. Can be uniformly dried. Here, the temperature rise inside the furnace may be started from normal temperature, which is a normal outside temperature, or may be started from a temperature higher than normal temperature in advance.
[0016]
Increasing the temperature inside the furnace gradually reduces the viscosity of the water, making it easier for the water to move quickly to the dry places in the clay, maintaining a uniform water distribution throughout the work. . As a result, the work does not dry locally only on the surface, and all parts of the work, both outside and inside, are dried in a well-balanced manner. Therefore, it is possible to prevent the occurrence of defects such as cracks, cracks, and warpage due to drying shrinkage of only the surface of the work. In addition, the water vapor pressure in the work clay increases with an increase in the temperature inside the furnace, so that the water in the work clay easily evaporates as water vapor, and drying can be promoted.
[0017]
The “predetermined drying temperature” that does not lead to the firing may be set to, for example, any temperature of 60 ° C. to 80 ° C., as described in the above [2]. If this temperature is used as the final heating temperature and the temperature is gradually increased from the temperature at the start of the heating over a period of time, the work can be efficiently and quickly completed without causing defects such as cracks, cracks, and warpage. It can be dried.
[0018]
Further, as described in the above [3], in the drying pattern (P0), the humidity inside the furnace is preferably maintained at around 80%. In this way, by drying the work in a high humidity atmosphere inside the furnace, it is possible to delay the progress of drying of the part or only the surface of the work, and sufficiently equalize the moisture distribution in the work clay Can be done.
[0019]
Further, as described in the above [4], if the drying pattern (P0) is composed of a plurality of steps, for example, the step of raising the temperature at a predetermined temperature rising gradient may be performed at a predetermined drying temperature. When the temperature has reached, optimal temperature management can be realized by combining steps for maintaining the temperature for a certain period of time or preparing a plurality of heating steps with different heating gradients.
[0020]
Further, as described in the above [5], it is preferable to prepare a plurality of different patterns for the dry pattern (P0) according to the properties of the clay or the shape and size of the work. For example, in general, the thicker the shape and the larger the capacity, the harder it is to dry, and the ease of drying varies considerably depending on the properties of each type of clay. A plurality of drying patterns (P0) having different drying temperatures, temperature rising gradients, required times, and the like are preferably prepared in advance, and the optimal drying pattern (P0) is preferably set so that it can be appropriately selected.
[0021]
In addition, as described in the above [6], after the drying pattern (P0) is completed, if a composite pattern that can be continuously transferred to the firing pattern (P1) is provided, the drying pattern (P0) It is possible to continuously perform the firing by the firing pattern (P1) without interrupting the processing once after the completion of the process, and it is possible to further shorten the time until the work is completed.
[0022]
Furthermore, as described in the above [7], if the firing pattern (P1) in the composite pattern is a pattern corresponding to the unfired among the plurality of fired patterns (P1), the unfired required before the main firing is performed. Can be continuously performed at once together with the drying.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment representing the present invention will be described with reference to the drawings.
1 to 13 show an embodiment of the present invention.
As shown in FIG. 1, an electric furnace 10 for pottery according to the present embodiment is for drying or firing a work contained in a furnace body 11, and includes a furnace body 11 formed in a box shape, It has a door body 20 for opening and closing the access opening 12 in the furnace body 11.
[0024]
The inner surface (the ceiling, the bottom surface, the inner wall, and the inner walls on both sides) of the furnace body 11 is covered with a heat insulating material 15 made of ceramic fiber. An outlet 12 is formed in the front wall 111 on the front side of the furnace body 11, and works are put in and out of the furnace surrounded by the heat insulating material 15 through the inlet 12. As shown in FIG. 3, a ventilation gap 16 is formed between the inner surface of the furnace main body 11 and the heat insulating material 15.
[0025]
A side wall groove 152 is formed in the side heat insulating material 151 of the heat insulating material 15 covering the inner surfaces on both sides of the furnace main body 11, and the heating unit 31 is fitted into the side wall groove 152. This prevents the heating unit 31 from protruding from the inner surface of the side heat insulator 151 into the furnace. Further, specifically, for example, the heating unit 31 cuts from one of both side edges of the elongated plate-shaped heating element toward the other side edge, and alternately processes such cuts in the longitudinal direction. It consists of
[0026]
A ceiling groove 154 is formed in the ceiling insulation 153 of the heat insulating material 15 covering the ceiling of the furnace body 11, and the ceiling groove 154 accommodates a temperature sensor 32 for detecting a furnace internal temperature. Have been. Thus, similarly to the heating section 31, the temperature sensor 32 does not protrude from the inner surface of the ceiling heat insulating material 153 into the furnace. The heating unit 31 and the temperature sensor 32 are connected to a control unit 50 described later via a signal line.
[0027]
As shown in FIG. 4, a front leg member 17 and a rear leg member 18 are provided on the bottom 112 of the furnace body 11 at the front and rear. The lower end portion 171 of the front leg member 17 extends to a position substantially on the same plane as the plane including the front portion 201 (see FIG. 2) of the door body 20 so that it does not protrude forward from the front of the electric furnace 10. Has become.
[0028]
A lower end portion 171 of the front leg member 17 is formed in a substantially U-shaped cross-sectional shape, and has a tray portion 172 that opens toward the lower edge of the inlet / outlet 12 of the furnace body 11. The rear leg member 18 has a hat channel cross-sectional shape that is opened upward, and similarly does not protrude rearward from the back surface of the electric furnace 10.
[0029]
Further, a cooling fan F is provided below the bottom 112 of the furnace main body 11, and a communication hole is formed in a destination of the cooling fan F, and the communication hole communicates with the ventilation gap 16. I have. The cooling fan F sends out the heated air in the ventilation gap 16 to the outside of the furnace main body 11 through the communication hole.
[0030]
As shown in FIG. 1, a hinge member 19 is provided on an opening side edge of the access opening 12, and a door body 20 is pivotally attached to the door member 20 by the hinge member 19 so as to be able to open horizontally. As shown in FIG. 5, the door body 20 is formed in a flat box shape, and an inner frame 21 is fitted into a frame 202 of the door body 20 with the bottom of the flat box as a front part 201. On the back side of the inner frame 21, an opening 22 corresponding to the entrance 12 is opened. In addition, ventilation holes are formed in the upper frame portion of the framework 202, the upper frame portion, the side frame portion, and the lower frame portion of the inner frame 21, respectively.
[0031]
Inside the inner frame 21, heat insulating materials 251 to 253, which are also ceramic fibers, are packed in three layers in front and back directions. Three layers of heat insulators 251 to 253 are sandwiched from the front and back directions by the holding plate 23 provided along the back surface of the framework 202 and the peripheral portion 221 of the opening 22 of the inner frame 21. In a fully closed state of the door body 20 that closes the access opening 12, the inside of the furnace sealed by the heat insulating material 15 around the access opening 12 and the heat insulating material 253 on the back side of the door body 20 is formed.
[0032]
Further, between the back surface of the front portion 201 of the door body 20 and the holding plate 23 along the back surface, and between the inner peripheral surface of the frame 202 of the door body 20 and the outer peripheral surface of the inner frame 21, ventilation is provided. Are formed. In addition, the back surface of the front part 201 of the door body 20 is a reflection surface for reflecting heat rays. The holding plate 23 is provided with a pair of left and right radiating fins 231.
[0033]
As shown in FIG. 1, a handle 29 provided with a lock mechanism 291 is provided on a side frame of the door body 20. The lock mechanism 291 prevents the door 20 from opening when the heating unit 31 is in the energized state, and allows the door 20 to open when the heating unit 31 is in the non-energized state. The energization state of the heating unit 31 is controlled by a control unit 50 described later.
[0034]
As shown in FIGS. 1 and 2, an operation box 40 is provided at the front of the electric furnace 10 beside the entrance 12. As shown in FIG. 3, a power supply unit 60 is provided inside the furnace main body 11 behind the operation box 40. A partition plate 61 is provided along the outside of the heat insulating material 15 forming one side inner surface of the furnace, and the partition plate 61 divides a space in which the power supply unit 60 is provided from the furnace side.
[0035]
The front wall 45 of the operation box 40 is formed on substantially the same plane as the front portion 201 of the door body 20. On the front wall 45, a display means 41, an operation panel 42, a counter 43, and a breaker 44 are provided. The operation panel 42 is provided with an input unit (course selection switch 421, confirmation switch 422, and up / down switch 424) and an operation switch 423. A control unit 50 is provided inside the operation box 40.
[0036]
The course selection switch 421 is a switch for selecting a desired course from, for example, 40 types of courses related to drying and baking (unglazed, main baked). Each time the button is pressed and the up / down switch 424 is pressed, The numbers 1 to 40 are sequentially displayed on the counter 43. When the confirmation switch 422 is pressed, the drying pattern P0 or the baking pattern P1 of the selected course is displayed on the display means 41 and the counter 43. Each time the operation switch 423 is pressed, the operation switch 423 alternately indicates a start state and a stop state of drying and baking.
[0037]
More specifically, out of the forty courses, for example, ten courses related to the numbers 1 to 10 are related to the drying pattern P0, and each of the drying patterns P0 is based on the properties of the clay forming the work or the properties of the work. Depending on the shape and size, different contents (such as how many times the temperature inside the furnace is raised or lowered over a number of hours) are predetermined in advance.
[0038]
Of the 40 types of courses, for example, 10 types of courses related to the numerals 11 to 20 are related to the firing of the firing pattern P1, and each firing pattern P1 relating to the firing is a work similar to the drying pattern P0. Depending on the properties of the clay to be shaped or the shape and size of the work, different contents (such as how many hours the temperature inside the furnace is raised or lowered over time, etc.) are predetermined.
[0039]
Further, among the 40 courses, for example, 20 kinds of courses related to the numbers 21 to 40 relate to the main firing of the firing pattern P1, and each firing pattern P1 relating to the main firing includes the type and properties of the glaze, Depending on the method of applying glaze (glazing) and the like, the contents are different from each other (such as how many hours the temperature inside the furnace is raised or lowered over time, etc.).
[0040]
Furthermore, it is also possible to configure so that a composite pattern that shifts to the firing pattern P1 continuously after the completion of the drying pattern P0 can be set. The firing pattern P1 in such a composite pattern corresponds to unglazing. Specifically, following the selection of the course of the drying pattern P0, when a course corresponding to unglazing is selected among the baking patterns P1 continuously within a predetermined time, a desired course relating to the drying pattern P0, What is necessary is just to set so that the desired course regarding the firing pattern P1 is continuously executed.
[0041]
The control unit 50 sequentially sends numerical information on the courses 1 to 40 to the counter 43 each time the button of the course selection switch 421 is pressed and the up / down switch 424 is pressed. The drying pattern P0 and the baking pattern P1 relating to the selected course are read out from the storage unit 53 based on the confirmation signal when the button of the confirmation switch 422 is pressed, and are sent to the display unit 41 and the counter 43. The storage unit 53 stores a dry pattern P0 and a firing pattern P1 for each course.
[0042]
Here, the drying pattern P0 and the firing pattern P1 each include a plurality of steps as shown in FIGS. 7 to 9 are tables in which time is set on the horizontal axis and temperature is set on the vertical axis, and each pattern P0, P1 is schematically represented by a line graph. Each line of the line graph corresponds to a plurality of steps forming each of the patterns P0 and P1. Here, each step is a heating step to reach the final heating temperature with a predetermined heating gradient, a heating step for continuously maintaining the final heating temperature for a predetermined time, and a cooling step in which heating is stopped after the heating step is completed. Are appropriately combined.
[0043]
Specifically, a basic course related to unglazing in the firing pattern P1 is shown in FIG. This course is composed of steps 1 and 2 which start from a normal temperature (origin) and have different heating gradients, and a step 3 in which cooling is performed immediately after reaching the final heating temperature (Temp2). For example, the intermediate temperature (Temp1) in Step 1 is 500 ° C., the required time (Time1) in Step 1 is 180 minutes, the final heating temperature (Temp2) in Step 2 is 780 ° C., and the required time (Time2) in Step 2 is 120. Equivalent to a minute.
[0044]
FIG. 8 shows a basic course relating to the main firing in the firing pattern P1. This course is composed of steps 1 and 2 which start at room temperature (origin) and have different temperature rising gradients, step 3 for maintaining the final heating temperature for a predetermined time, and step 4 for cooling after that. For example, the intermediate temperature (Temp1) in Step 1 is 900 ° C. and the required time (Time1) in Step 1 is 180 minutes, and the final heating temperature (Temp2) in Step 2 is 1200 ° C. and the required time (Time2) in Step 2 is 240. Minutes, and the time required for Step 3 (Time3) corresponds to 30 minutes.
[0045]
FIG. 9 shows a basic course of the drying pattern P0. This course is started from a temperature (Temp1; for example, using the residual heat inside the furnace) higher than normal temperature (origin), and is continuously maintained at a predetermined heating gradient step 1 and a final heating temperature (Temp2) for a predetermined time. Step 2 is followed by Step 3 of cooling. For example, the starting temperature (Temp1) in Step 1 is 40 ° C., the final heating temperature (Temp2) is 80 ° C., the required time in Step 1 (Time1) is 360 minutes, and the required time in Step 2 (Time2) is 180 minutes. I do. The final heating temperature in such a drying pattern P0 is a “predetermined drying temperature” that does not lead to firing, as will be described in detail later, and is set to an arbitrary temperature from 60 ° C. to 80 ° C.
[0046]
FIG. 10 shows a course of a composite pattern in which, after the completion of the drying pattern P0, the process proceeds to the firing pattern P1 continuously. This course is set so that, after steps 1 and 2 of the drying pattern P0 shown in FIG. Here, in Step 3, for example, the final heating temperature (Temp3) may be appropriately set to 780 ° C., and the required time (Time1) may be set to 300 minutes or the like. Of course, these specific temperatures, times, and combinations in the composite pattern are merely examples.
[0047]
In the storage unit 53 of the control unit 50, individual temperatures, required times, and the like corresponding to steps for each of the drying patterns P0 and the respective firing patterns P1 are recorded. The control unit 50 calculates the elapsed time T from the start of the drying and baking, records the elapsed time T in the storage unit 53, and sets the currently executing step to be displayed on the display unit 41. Have been.
[0048]
Further, when the firing is interrupted, the control unit 50 continues to display on the operation panel 42 that the firing is interrupted. Then, as shown in FIG. 11, the firing resumption means 52 of the control unit 50 performs the firing after the elapsed time T when firing is interrupted (sintering scheduled to be performed if firing is not interrupted) as described above. It is set to restart based on the fired pattern P1.
[0049]
That is, the control unit 50 writes the interruption period T1 from the interruption of the firing to the return to the storage unit 53 after the interruption. Then, based on the elapsed time T from the start of firing and the interruption period T1, the elapsed time (T-T1) when firing is interrupted may be returned. For example, when the door 20 is opened and the temperature t1 inside the furnace becomes lower than the predetermined temperature t0 (including an allowable error), the control unit 50 determines that the firing has been interrupted. Further, when the door body 20 is closed and the temperature t1 inside the furnace starts to rise, the control unit 50 determines that the operation is "return".
[0050]
The control unit 50 determines whether or not the suspension period T1 exceeds the predetermined time Tmax. If the suspension period T1 does not exceed the predetermined time Tmax, the firing is performed again after the termination (return) of the suspension period T1. The control unit 50 controls the lock mechanism 291 to prevent the door 20 from being opened when the heating unit 31 is in an energized state, that is, during drying or firing. Note that the predetermined drying temperature in the drying pattern P0 is much lower than that of the firing pattern P1, and therefore, it is not necessary to provide a restarting measure when drying is interrupted. May be configured.
[0051]
One of the side walls 46 of the operation box 40 (the one closer to the entrance 12) is coated with silver. The present invention is not limited to this, and the side wall 46 closer to the inlet / outlet 12 only needs to be a reflecting surface for reflecting heat radiated from the inside of the furnace main body 10. Is also good.
[0052]
A partition plate 47 is provided inside the operation box 40 along the silver-coated side wall 46, and a ventilation gap 48 is formed between the side wall 46 and the partition plate 47. Have been. Vent holes 49 are formed at the upper end and the lower end of the ventilation gap 48, and the ventilation gap 48 communicates with the outside air through the ventilation hole 49.
[0053]
Next, the ceramic electric furnace 10 will be described.
The inside of the furnace main body 11 is heated by the heating unit 31 provided in the furnace main body 11, and the work contained in the furnace main body 11 is dried or fired. The course of the drying pattern P0 or the firing pattern P1 suitable for each work is selected in advance, and the heating by the heating unit 31 is controlled by the control unit 50.
[0054]
First, drying of a work using the electric furnace 10 for pottery will be described.
In FIG. 12, when the main power switch is first turned on (S101), the heating unit 31 can be energized. However, when the heating unit 31 is not energized yet, the lock is controlled by the control unit 50. The mechanism 291 is in an unlocked state, and the door 20 can be opened. At this time, the door 20 is opened sideways, and the work is put into the furnace through the access opening 12.
[0055]
When the work is put into the furnace, the heating unit 31 does not protrude from the wall surface of the side heat insulator 151 into the furnace, and the temperature sensor 32 does not protrude from the inner surface of the ceiling heat insulator 153 into the furnace. Does not hit the heating unit 31 or the temperature sensor 32, and the work and the heating unit 31 can be prevented from being mutually damaged.
[0056]
After the work is stored inside the furnace and the main power switch is turned on, each time the button of the course selection switch 421 of the operation panel 42 is pressed and the up / down switch 424 is pressed, the numbers related to the courses 1 to 40 are displayed on the counter 43. Displayed sequentially. Then, any one of the courses 1 to 10 relating to the drying pattern P0 is selected by displaying it on the counter 43 (S102).
[0057]
A plurality of courses 1 to 10 different from each other are prepared for the drying pattern P0 selected here according to the properties of the clay or the shape and size of the work as described above. As these selection criteria, generally, the thicker the shape and the larger the volume, the harder it is to dry, and the ease of drying varies considerably depending on the properties of each type of clay. The respective courses 1 to 10 relating to the optimum drying pattern P0 may be appropriately selected.
[0058]
Each of the courses 1 to 10 according to the drying pattern P0 includes a plurality of steps as shown in an example in FIG. 9. At that point, the temperature is set so that optimal temperature management can be realized by combining steps for maintaining the temperature for a certain period of time or preparing a plurality of heating steps with different heating gradients from each other. I have.
[0059]
When the button of the confirmation switch 422 is pressed, the drying pattern P0 of the selected course is displayed on the display means 41 (S103). At this time, the features of the steps forming the course relating to the drying pattern P0 are also displayed. The creator who uses the furnace selects the course relating to the drying pattern P0 suitable for the work while referring to the features of the steps displayed on the display means 41, so that the optimum course can be selected without error. it can.
[0060]
Next, when the button of the operation switch 423 is pressed, the heating unit 31 is turned on, and drying of the work based on the previously selected drying pattern P0 is started (S104). Then, the lock mechanism 291 is in the locked state, so that the door 20 cannot be opened, and the door 20 is locked (S105). During the drying, the control unit 50 controls the power supply to the heating unit 31 based on the course of the selected drying pattern P0 (S106).
[0061]
When the drying is completed (S107: Y) and the temperature inside the furnace becomes equal to or lower than the predetermined temperature (S108: Y), the locking of the door 20 by the lock mechanism 291 is released (S109). At this time, the creator can open the door body 20 and take out the work dried inside the furnace.
[0062]
As described above, apart from the firing pattern described later, a drying pattern for drying the work inside the furnace over time is provided.In this drying pattern, a work formed from clay is put in the furnace as soon as possible, and By gradually raising the inside of the furnace to a predetermined drying temperature (for example, the aforementioned 80 ° C. or the like) that does not result in firing, the entire work can be uniformly dried. Here, as described with reference to FIG. 9, the temperature rise inside the furnace may be started from a temperature higher than a normal ambient temperature, which is a normal ambient temperature, by utilizing residual heat or the like after the previous firing. As in the case of the sintering shown in FIGS.
[0063]
In S106 in FIG. 12 described above, if the temperature inside the furnace is gradually increased, the viscosity of the moisture in the work clay decreases, and the moisture easily moves to a dry place in the clay. That is, the water distribution in the whole work is kept uniform. As a result, the work does not dry locally only on the surface, and all parts of the work, both outside and inside, are dried in a well-balanced manner.
[0064]
Therefore, it is possible to prevent the occurrence of defects such as cracks, cracks, and warpage due to drying shrinkage of only the surface of the work. Moreover, as the temperature inside the furnace increases, the water vapor pressure in the work clay increases, so that the water in the work clay easily evaporates as water vapor, and drying can be further promoted.
[0065]
The “predetermined drying temperature” that does not lead to the firing is 80 ° C. in the example described with reference to FIG. 9, but may be set to an arbitrary temperature from 60 ° C. to 80 ° C. If the temperature is gradually increased from the temperature at the start of the heating, for example, about 6 hours, and then maintained at the final heating temperature for about 3 hours, the work will have cracks, cracks, warpage, etc. It is possible to dry the work efficiently and in a short time without causing the problem described above.
[0066]
According to the experimental data by the inventors, if the “predetermined drying temperature” is lower than 60 ° C., it takes a considerable amount of time to dry sufficiently, and if it exceeds 80 ° C., the work will have cracks, It has been found that the possibility of occurrence of defects such as cracks and warpage increases.
[0067]
In the drying pattern, the humidity inside the furnace is maintained at around 80%. In this way, by drying the work in a high humidity atmosphere inside the furnace, it is possible to delay the progress of drying of the part or only the surface of the work, and sufficiently equalize the moisture distribution in the work clay Can be done.
[0068]
The humidity inside the furnace becomes nearly 100% high due to the water vapor evaporated from the clay during drying, but the relative humidity inside the furnace can be lowered by increasing the temperature inside the furnace with an appropriate temperature gradient. By appropriately setting the heating step and the heating step in the pattern, it is possible to dry the furnace while maintaining the humidity inside the furnace at around 80%.
[0069]
In addition, since the water evaporated from the work clay expands about 1000 times, it rises in the gap with the hot air flowing through the ventilation gap inside the upper frame and the lower frame of the door body 20, and the ventilation hole of the upper frame is opened. And is discharged outside. When there is a difference between the atmosphere temperature of the inside of the furnace and the ambient temperature of the outside air, outside air enters the inside of the furnace from the ventilation hole in the lower frame of the door body 20 through the ventilation gap, and the humidity inside the furnace is reduced appropriately. There is also an action to make it.
[0070]
Furthermore, as described above, after the completion of the drying pattern, if the composite pattern is set so as to be able to continuously shift to the firing pattern, the processing can be continuously performed without interrupting the processing once after the completion of the drying pattern. Can be performed, and the time until the work is completed can be further reduced.
[0071]
More specifically, when the drying temperature is relatively high (around 80 ° C.), in order to check the drying state, it is not possible to take out from the inside of the furnace unless it is cooled, but the drying result of the electric furnace 10 for ceramics in which the drying result is guaranteed to some extent In this case, the process can be switched from drying to unglazing without confirmation, so that the process can be significantly shortened.
[0072]
Next, baking of a work using the electric furnace 10 for pottery will be described.
In FIG. 13, as in the case of the above-described drying pattern, when the main power switch is first turned on (S201), the heating unit 31 is energized, but the heating unit 31 is not energized yet. Then, under the control of the control unit 50, the lock mechanism 291 is in the unlocked state, and the door body 20 can be opened. At this time, the door 20 is opened sideways, and the work is put into the furnace through the access opening 12.
[0073]
Subsequently, each time the button of the course selection switch 421 of the operation panel 42 is pressed and the up / down switch 424 is pressed, the numbers related to the courses 1 to 40 are sequentially displayed on the counter 43. Then, a desired one of the courses 11 to 40 (the unbaked courses 11 to 20 and the main baked courses 21 to 40) relating to the firing pattern P1 is selected by displaying it on the counter 43 (S202).
[0074]
When the button of the confirmation switch 422 is pressed, the firing pattern P1 of the selected course is displayed on the display means 41 (S203). At this time, the features of the steps forming the course relating to the firing pattern P1 are also displayed. Since the creator using the furnace selects the course relating to the firing pattern P1 suitable for the work while referring to the features of the steps displayed on the display means 41, the optimum course can be selected without error. it can.
[0075]
Next, when the button of the operation switch 423 is pressed, the heating unit 31 is turned on, and firing of the work based on the preselected firing pattern P1 is started (S204). Then, the lock mechanism 291 is in the locked state, so that the door 20 cannot be opened, and the door 20 is locked (S205). During firing, the control unit 50 controls power supply to the heating unit 31 based on the course of the selected firing pattern P1 (S206).
[0076]
During firing, the state of the door body 20 (open state or closed state) is determined (S207). The counter 43 displays the furnace internal temperature. If the door body 20 is in the closed state (S207: closed), during firing, it is determined whether firing is completed based on the elapsed time T from the start of firing (S208).
[0077]
When the firing is completed (S208: Y) and the temperature inside the furnace becomes equal to or lower than the predetermined temperature (S209: Y), the locking of the door body 20 by the lock mechanism 291 is released (S210). At this time, the creator can open the door body 20 and take out the fired work from the inside of the furnace.
[0078]
On the other hand, when the door body 20 is opened (S207: open), the control unit 50 stops supplying power to the heating unit 31 to suspend the firing, and stores the elapsed time T from the start of firing in the storage unit 53. It is recorded (S211). At this time, the operation panel 42 displays that the firing is being interrupted.
[0079]
During the interruption of the firing, the state of the door body 20 (open state or closed state) is determined (S212). When the door body 20 is in the closed state (S212: closed), as shown in FIG. 11, firing after an elapsed time T from the start of the recorded firing (if not interrupted, the firing is scheduled to be performed after the interrupted time). Is restarted based on the course of the selected firing pattern P1 (S213).
[0080]
As described above, when the firing is interrupted and the door 20 is closed, the firing restarting means 52 automatically performs the firing again, so that the firing again does not need to rely on the intuition of the author. Also, there is no need to restart firing from the beginning or to abandon firing the work. In addition, since almost the same amount of heat as in the case where there is no interruption of firing is supplied in the second firing after the interruption, the fired work becomes similar to the fired work without interruption of firing.
[0081]
Although the embodiments of the present invention have been described with reference to the drawings, the specific configuration is not limited to these embodiments, and even if there are changes and additions without departing from the gist of the present invention, the present invention is not limited to the embodiments. Included in the invention. For example, in the above-described drying pattern, even when there is an interruption during the execution, the drying may be automatically performed again as in the case of the interruption of the baking by the drying resuming means provided separately. good.
[0082]
In the above-described embodiment, the course selection switch 421 for selecting the course and the confirmation switch 422 for confirming the selected drying pattern P0 or firing pattern P1 are different from each other. May be displayed on the display means 41 when the selected drying pattern P0 or firing pattern P1 is selected.
[0083]
Further, a display means 41 for displaying a graph relating to the selected drying pattern P0 or firing pattern P1 and a counter 43 for displaying a number relating to the selected drying pattern P0 or firing pattern P1 are separately provided. Although the provided one is shown, such a graph and a number may be displayed together on the same display means.
[0084]
Furthermore, by sequentially lighting each step (each line of the line graph) relating to the drying pattern P0 and the baking pattern P1, each step relating to the selected drying pattern P0 and the baking pattern P1 is changed to the drying pattern P0 and the baking pattern P1. You may make it display sequentially on the display means 41 at the time of the confirmation operation of the pattern P1. Such a sequential display of the steps may be performed continuously during the drying or baking, or may be performed during a confirmation operation (when the button of the confirmation switch 422 is pressed).
[0085]
【The invention's effect】
According to the electric furnace for pottery according to the present invention, apart from a predetermined firing pattern, a drying pattern for drying the work contained in the furnace over time is provided. By gradually increasing the temperature to a predetermined drying temperature that does not lead to firing over time, the entire work can be uniformly dried.
[0086]
In other words, when the temperature inside the furnace is gradually increased, the viscosity of the water decreases, so that the water easily moves to dry places in the clay, and the water distribution throughout the work is kept uniform. Because of the sagging, the work does not dry locally on the surface alone, but on all parts of the work, both outside and inside, in a well-balanced manner.
[0087]
Therefore, it is possible to prevent defects such as cracks, cracks, and warpage due to drying shrinkage or insufficient drying of only the surface of the work, and it is possible to reliably perform optimal drying. Moreover, as the temperature inside the furnace rises, the water vapor pressure in the clay becomes higher, so that the water in the clay becomes more likely to evaporate as water vapor. Can be greatly reduced.
[0088]
In addition, by maintaining the humidity inside the furnace at around 80% in the drying pattern, the work is dried in a high humidity atmosphere inside the furnace, and the progress of the drying of a part or only the surface of the work is prevented. By delaying it, the moisture distribution in the work clay can be sufficiently averaged.
[0089]
Furthermore, after the drying pattern is completed, if a composite pattern capable of continuously shifting to the firing pattern is provided as it is, the firing by the firing pattern is continuously performed without interrupting the processing once after the drying pattern is completed. Can be implemented, and the time until the work is completed can be further reduced.
[Brief description of the drawings]
FIG. 1 is a three-dimensional view of a state in which a door of an electric furnace for ceramics according to an embodiment of the present invention is opened, as viewed from the front side.
FIG. 2 is a front view of an electric furnace for pottery according to one embodiment of the present invention.
FIG. 3 is a plan view of the electric furnace for pottery according to one embodiment of the present invention.
FIG. 4 is a side view of a ceramic electric furnace according to one embodiment of the present invention.
FIG. 5 is an exploded perspective view showing a door of the electric furnace for ceramics according to one embodiment of the present invention.
FIG. 6 is a functional block diagram of an electric furnace for pottery according to one embodiment of the present invention.
FIG. 7 is an explanatory diagram showing an example of a firing pattern according to one embodiment of the present invention.
FIG. 8 is an explanatory diagram showing another example of a firing pattern according to one embodiment of the present invention.
FIG. 9 is an explanatory diagram illustrating an example of a drying pattern according to an embodiment of the present invention.
FIG. 10 is an explanatory diagram showing an example of a composite pattern that shifts to a firing pattern continuously after the end of a drying pattern according to an embodiment of the present invention.
FIG. 11 is an explanatory diagram showing an example of a pattern for automatically performing firing again when there is an interruption during execution of a firing pattern according to an embodiment of the present invention.
FIG. 12 is a flowchart showing a drying operation of the electric furnace for pottery according to one embodiment of the present invention.
FIG. 13 is a flowchart showing a firing operation of the electric furnace for pottery according to one embodiment of the present invention.
[Explanation of symbols]
10 ... Electric furnace
11 Furnace body
12 ... Doorway
15 ... Insulation material
16 ... Ventilation gap
17 ... Fore leg member
18 ... rear leg members
19 ... Hinge member
20 ... door
21 ... Inner frame
22 ... Opening
23 ... holding plate
29 ... handle
31 ... Heating section
32 ... Temperature sensor
40… Operation box
41 ... display means
42 ... Operation panel
43 ... Counter
48 ... Ventilation gap
49… Vent
50 ... Control unit
52. Firing resumption means
53 ... storage unit
60 ... power supply unit
61 ... Partition plate
421: Course selection switch
422 ... Confirmation switch
423… Operation switch

Claims (7)

In an electric furnace for pottery, which fires works stored in the furnace based on a predetermined firing pattern,
Separately from the firing pattern, provided with a drying pattern for drying the work inside the furnace over time,
In the drying pattern, the inside of a furnace containing a work formed from clay is gradually heated over a period of time to a predetermined drying temperature that does not lead to firing, so that the viscosity of water in the clay is reduced and the temperature in the clay is reduced. An electric furnace for pottery, characterized in that the entire work is dried uniformly by increasing the water vapor pressure in the furnace. The electric furnace for ceramics according to claim 1, wherein the predetermined drying temperature is set to an arbitrary temperature from 60C to 80C. The electric furnace for pottery according to claim 1 or 2, wherein in the drying pattern, the humidity inside the furnace is maintained at about 80%. 4. The electric furnace for ceramics according to claim 1, wherein the drying pattern comprises a plurality of steps. The electric furnace for ceramics according to claim 1, 2, 3 or 4, wherein a plurality of different patterns are prepared according to the properties of the clay or the shape and size of the work. . The electric furnace for pottery according to claim 1, further comprising a composite pattern capable of continuously shifting to the firing pattern as it is after completion of the drying pattern. The electric furnace for ceramics according to claim 6, wherein the firing pattern in the composite pattern is a pattern corresponding to unglazing out of a plurality of firing patterns.

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