JPS61171084A - Ceramic kiln - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Minute Hand) The present invention relates to a pottery furnace in which the current supplied to the heater is variable and the temperature is automatically adjusted in accordance with a predetermined temperature curve.

(Background technology) In pottery, there are two types of firing for works: unglazed firing and main firing.
The work is fired at a temperature of about 1,300 degrees Celsius, and hon-yaki is a process in which the unglazed work is coated with glaze and then fired at a temperature of about 1,300 degrees Celsius.

However, the relationship between temperature and time is important in this firing, and in order to bake the work beautifully without failure,
It is necessary to raise or lower the temperature according to a predetermined temperature curve. In other words, the shrinkage rate is different depending on the temperature at the start of firing, for example, when the firing starts, and the shrinkage rate is different depending on the temperature, which may cause cracks in the work or during firing. When the temperature rise was lower than the temperature at which the glaze melted, or when the glaze was kept at the melting temperature for a short time, the glaze did not melt sufficiently, causing unevenness in the work.

Also, if the rising temperature is too high than the melting temperature of the glaze,
If the glaze was kept at its melting temperature for too long, the glaze would flow too much, causing unevenness and sagging on the work.

Therefore, in a pottery furnace equipped with a conventional heater, in addition to constantly measuring the temperature and time inside the furnace, the power switch is opened and closed to match a predetermined temperature curve, and the volume control is used to adjust the current supplied to the heater. It is very time-consuming to adjust the temperature by adjusting the temperature, and the disadvantage is that someone must be present for a long time until the work is baked, as it is necessary to constantly adjust the temperature. there were.

(Object of the Invention) The present invention has been proposed in view of the above points, and its purpose is to automatically adjust the current supplied to the heater in accordance with a predetermined temperature curve, and to The object of the present invention is to provide a pottery furnace whose temperature is adjusted according to a predetermined temperature curve.

(Disclosure of invention) DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to drawings showing embodiments.

FIG. 1 is an external view of a pottery furnace showing one embodiment of the present invention, and the pottery furnace is composed of a furnace 1 and a control section 2. As shown in FIG. Furnace 1
A box-shaped housing 3 with an open top surface, and a lid 4 attached to the top surface of the housing 3 with a hinge 13 so as to be openable and closable.
It consists of a housing 3 in which pottery is housed. The housing 3 is framed with refractory bricks 5, its inner surface is covered with asbestos 6, and its outer surface is covered with a sheet metal 77. A heater 8 formed into a wave shape is attached. A through hole 9 is formed in one side of the housing 3 to communicate the inside of the housing 3 with the outside, and a temperature sensor 10 such as a thermocouple as shown in FIG.
is inserted through the through hole 9 and arranged inside the housing 3. Note that 43 is a code. There is a handle 11 on the lid 4.
is attached, and rollers 12 for movement are provided on the bottom surface of the housing 3.

The control section 2 has a circuit section built inside a box-shaped housing 14, and one side of the housing 14 is inclined, and a display section 15.1B and an operation switch (start switch, step changeover switch) 17 are provided on that surface. .18 and a numeric keypad 20 for setting the temperature for 2 hours. Moreover, a moving roller 21 is provided on the bottom surface of the housing 14.

FIG. 3 is a block diagram showing an example of a circuit configuration, and shows a basic configuration in which a set temperature and a set time are set. In the figure, the output signal of the temperature sensor 1G provided in the furnace 1 is given to the display unit 16 to display the temperature inside the furnace, and is also given to the comparison circuit QI 37 to control approximately 38. The electric current supplied from the electric power source 1Iji41 to the heater 8 provided in the furnace 1 can be varied.

On the other hand, the temperature setting circuit 312 and the time setting circuit 32 can be set using the numeric keyboard 20 (Fig. 1).
The output signal is the temperature memory circuit 33. Time memory port Ws34
are given to each. Next, the output signal of the temperature memory circuit 33 and the output signal of the time memory circuit 34 are given to a predetermined temperature calculation port $35, and the output signal of the predetermined temperature calculation circuit 35 and the output signal of the temperature sensor 10 are are compared in a comparison circuit 37. Further, a timer 36 is provided for supplying a time signal to the predetermined temperature calculation circuit 35, and a signal is also supplied to the timer 36 from the time storage circuit 34.

Furthermore, a display section 15 is connected to the predetermined temperature calculation circuit 35, so that the calculation results can be displayed.

The operation will be explained below. First, operate the numeric keyboard 20 to set the desired temperature and time.
! 1i! iu 161r65 meat N 'fRAt K'
When set so that rs tr, the temperature setting circuit 31
and 1. from the time setting circuit 32 to the set temperature. Setting time T
.

Signals corresponding to the above are outputted and stored in the temperature storage circuit 33 and the time storage circuit 34, respectively. Next, when the start switch 17 is pressed, current is supplied from the power source 41 to the heater 8 to start firing, and at the same time, the predetermined temperature at each time is calculated at the predetermined temperature calculation port $35. That is, the predetermined temperature calculation circuit 35 calculates the predetermined temperature K at each time based on the set temperature stored in the temperature storage circuit 33 and the set time T 2 stored in the time storage circuit 34.

Here, the predetermined temperature at each time t is, for example, = (
K /T ) t may be used. This is determined by the predetermined temperature K as shown in FIG.
increases in proportion to time, and the elapsed time t is given by the timer 36 and changes from 0 to 4T1.

Next, the signal corresponding to the predetermined temperature K at each time output from the predetermined temperature calculation circuit 35 is compared with the actual furnace temperature detected by the temperature sensor 10 in the comparison circuit 37. The comparison circuit 37 compares the predetermined temperature with the furnace temperature and outputs a signal corresponding to the difference between the two, that is, K-k. The current control circuit 38 changes the current supplied from the power supply 41 to the heater 8 in response to the output signal of the comparison circuit 37, and when K-k>0 (when the furnace temperature k is low due to a predetermined temperature), both The current supplied to the heater 8 is increased according to the magnitude of the difference between the two, and when K- is ≦0 (when the furnace temperature k is higher or equal to the predetermined temperature), the supplied current is decreased or made zero. .

Through these operations, the current supplied to the heater 8 is constantly adjusted so that the temperature inside the furnace is equal to a predetermined temperature, and the temperature inside the furnace reaches 1° C. after 12 hours as initially set. Further, the predetermined temperature calculated by the predetermined temperature calculation circuit 30 and the furnace temperature detected by the temperature sensor 10 include, for example, 4 digits, 7 yag, 7. ). Display element, configuration ゎ6 Display section 1
5. Displayed on J16.

Next, FIG. 5 shows a system that can deal with the case where a predetermined temperature curve changes in a complicated manner, and the configuration is such that the temperature storage circuit 33 and the time storage circuit 34 can store a plurality of numerical values. It differs from the previous one in that it is

Therefore, Figure 6 (a) is a preferable furnace temperature curve known from experience, and in cases where the furnace temperature changes in a complex manner like this, the temperature and time curves are changed in multiple stages as shown in Figure 6 (b). may be set to approximate a predetermined temperature curve. below,
As an example, as shown in Fig. 6,
Consider a case in which the temperature inside the furnace rises to 2°C after 2 hours, further to 3°C after 13 hours, and then is maintained at 3°C for 14 hours. In this case, the temperature memory circuit 33 and the time memory diagram @34 each have a plurality of storage units 33(1) to 33(4), 34(
1) to 34 (4). First, a desired temperature and time are set by operating the numeric keyboard 20 in the same manner as described above. Here, in the first setting data, ,T,(
Step ■) is the temperature memory circuit 33 and the time memory circuit 3.
By pressing the step change key 18 in the memory section 3B(1), 34(1) of No. 4 to move to step ■, and inputting data using the numeric keyboard 20, this setting data will be changed to 2.
T2 (step ■) is stored in the storage units 33 (2) and 34 (
2), and from then on, the same operation is repeated sequentially to create the setting data, T3 (step ■), and 3. Store T4 (step ■).

When the data setting storage is completed, the start switch 17 is pressed to start firing. First, the predetermined temperature calculation circuit 35
The setting data 1. is stored in the storage units 33 (1) and 34 (1). T is input, and the predetermined temperature at each time = (Ki/T-,)t is calculated and output to the comparison circuit 37. Here, the timer 36 includes a time memory circuit 34.
A signal corresponding to the set time T1 is output from the storage unit 34 (1), and the timer 36 outputs a time signal t that increases from 0 to T1 to the predetermined temperature calculation circuit 35. timer 3
6 outputs a signal to the temperature memory circuit 33 and time memory circuit 34 when t=T, and when the temperature setting circuit 33 and time memory circuit 34 receive this signal, they shift from step ■ to step ■. , T2 is output to the predetermined temperature calculation circuit 35 as setting data from the next storage units 33 (2) and 34 (2). As a result, the predetermined temperature calculation time $35 is -C
(on K2-) /T2) on t+ and outputs it to the comparator circuit 37. After that, when t=T, step ■
Then, the predetermined temperature calculation circuit 35 adjusts the predetermined temperature to the predetermined temperature.
K, -2) /T3) Calculate t-zc2, then t
= T3, proceed to step ■ and set the predetermined temperature K =
K3 is output to the comparison circuit 1tI37, and the comparison circuit 37 constantly compares the furnace temperature and each predetermined temperature, and adjusts the current supplied to the heater 8 according to the difference between the two. As a result, the current supplied to the heater 8 is always adjusted so that the furnace temperature is equal to each predetermined temperature, and the furnace temperature is adjusted to the sixth temperature.
It follows the temperature curve approximated in figure (a). Incidentally, FIG. 7 shows the above operation in a flowchart.

In addition, when approximating the temperature curve shown in FIG. 6(a), a large number of memory sections of the temperature memory circuit 33 and the time memory circuit 34 are provided, and a predetermined temperature curve is divided into a large number of steps, and each step is All you have to do is set the temperature and time.
Further, in the case of storing a plurality of predetermined temperature curves, a plurality of temperature storage circuits 33 and a plurality of time storage circuits #I34 may be provided. In this case, the firing temperature curve is
It can be stored separately for the case of hon-yaki, etc., and can be selected and used as appropriate.

Further, in the above configuration, the current control circuit 38 is constituted by a thyristor or the like, and the temperature setting circuit 31, the time setting circuit 32 . Temperature memory circuit 332 Time memory circuit 34. Predetermined temperature calculation circuit 35. The timer 36° comparison circuit 37 and the like are constructed of a one-chip microcomputer and the like. Furthermore,
The furnace 1 and the control unit 2 are connected via a cord.
, + is available, which is convenient when cleaning the inside of the furnace.

(Effects of the Invention) As described above, the present invention includes a housing provided with a Tanabata, a sensor for detecting the temperature inside the housing, a temperature setting means for setting the temperature, and a device for setting the time. a time setting means; a calculation means for calculating a predetermined temperature at each time from the temperature set by the temperature setting means and the time set by the time setting means; and a predetermined temperature calculated by the temperature detected by the sensor and the calculation means. and a control means that obtains the output signal of this comparison means and varies the supply current to Tanabata, so that the set temperature and The current supplied to the heater is adjusted according to the predetermined temperature at each time calculated from the set time, and the furnace temperature is automatically adjusted according to the predetermined temperature, so the current supplied to the heater is adjusted according to the furnace temperature and time. There is no need to adjust the temperature while measuring it, and there is no need to constantly adjust the temperature for long periods of time, making it easy to fire pottery.

[Brief explanation of the drawing]

Figure 1 is an external view of the pottery furnace of the present invention, and Figure 2 is a diagram of the pottery furnace of the present invention.
- Yu Hashiyama Gap 1r Head l 10 "1 Atsunori Meimu Sasana block diagram, Figure 4 is an explanation diagram of its operation, Figure 5 is a block diagram showing other circuit configurations, Figure 6 is an explanation of its operation. 7 are flowcharts showing details of the operation. 1...Furnace, 2...Control unit, 3, 14.
...Housing, 4...Lid, 5...
... Firebrick, 6... Asbestos, 7...
Sheet metal, 8... Heater, 9... Through hole,
10... Temperature sensor, 11... Handle,
12.21...Koro, 13...Hinge,
Is, 16...Display section, 17.18...
...Operation switch, 20...Numeric keyboard,
31... Temperature setting circuit, 32... Time setting circuit, 33... Temperature storage circuit, 34...
... Time memory circuit, 35 ... Predetermined temperature calculation circuit, 36 ... Timer, 37 ... Comparison circuit, 38 ... Current control circuit, 41・・・・・・
・Power supply, 42.43...Code 1st prisoner, Figure 2, tR3, Figure 4, Figure 11

Claims (3)

[Claims] (1) A housing equipped with a heater, a sensor for detecting the temperature inside the housing, a temperature setting means for setting the temperature, a time setting means for setting the time, and the temperature and the time set by the temperature setting means. calculation means for calculating a predetermined temperature at each time from the time set by the setting means;
Comparing means for comparing the temperature detected by the sensor with a predetermined temperature calculated by the calculating means and outputting a signal according to the difference between the two; and obtaining an output signal of the comparing means to vary the current supplied to the heater. A pottery furnace characterized by comprising a control means. (2) The pottery furnace according to claim 1, wherein the temperature setting means and the time setting means can be set from the outside using a numeric keypad. (3) Claim 1, in which a housing equipped with a heater and a control section having circuit sections such as temperature setting means, time setting means, calculation means, and control means are connected by a detachable cord. pottery furnace.