JPS6026178B2 - Automatic moisture content measuring device in dryer - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a device that automatically measures the moisture content of a material to be dried, such as paddy, in a dryer, and stops the operation of the dryer when the target moisture content is reached.

[Conventional technology]

In a grain dryer, a sample being dried (grain to be dried) is collected, crushed between a pair of electrodes, and electrical resistance, capacitance, etc. between the electrodes are measured. In such a dryer, the moisture content is measured at appropriate time intervals, and as the moisture content decreases and approaches the target value, the measurement interval becomes shorter. However, there is no particular need to perform measurements at the initial stage of drying. In other words, if the measurement is carried out at an early stage when the moisture content is high, the high-moisture grain flour particles crushed between the electrodes may adhere to the electrode surface, causing errors in subsequent measurements.

OBJECT OF THE INVENTION 1 Accordingly, it is an object of the present invention to provide an apparatus that can eliminate the above-mentioned inconvenience by making it possible to set the waiting time until the start of measurement at the beginning of drying. [Embodiment 1] An embodiment of the present invention will be described below with reference to the drawings. In the figure, reference numeral 1 indicates a measuring device that crushes rice between a pair of electrodes and generates a voltage signal that is inversely proportional to the electrical resistance between the electrodes; 2;
is an integration circuit, 3 is a comparison circuit, 4 is a measurement interval control circuit, and 5
6 is a measurement flag circuit, 7 is a 2-second clock pulse generation circuit, 8 is a two-stage cutoff graph circuit, 9 is a stop circuit, and 10 is a measurement delay time setting circuit. In addition, in the field setting machine 1, the sample blood is in a standby position, and the standby limit switch WTB is open at that position. The sample blood is moved forward by the operation of the motor for collecting the sample, and stopped by opening the limit switch WB at the forward end, and after a certain period of time, the motor is reversed, and the limit switch BW is opened by the retracting machine.
It is designed to open LS. The measurement interval control circuit 4 includes a running oscillation 8-minute clock pulse generation circuit B-2, a counter C-3, and input terminals B, C, and C of the counter C-3.
OR gates GA-1, GA-2, GA-3 connected to D
Consisting of The measurement delay time setting circuit 10 also includes setting switches IS-1, IS-2.1S-3, which output level signals of high level (hereinafter referred to as day) and low level (hereinafter referred to as L);
It consists of AND gates GA-4, GA-5, and GA-6 whose input conditions are a conference bell signal and a power-on signal mIT. When the power is turned on and the dryer starts operating, an INIT signal is generated for a certain period of time.
The signal activates the free-running 8-minute clock pulse generation circuit B-2 via the OR gate GA-7, and the INIT signal loads the counter C-3 via the gate GA-8 to count the 8-minute clock pulses. Begin to. On the other hand, gates GA-4, GA-5, G
A-6 is turned on, and switches IS-1, IS-2, and I
The time set by S-3 is set and held in counter C-3. At this time, comparison circuit F of comparison circuit 3
Since the outputs from −1, F-2, and F-3 are L, the gate G
Signals from A-4, GA-5, and GA-6 are prioritized.
Further, since the counter C-1 is cleared, the AUTO signal becomes L. When the counter C-3 counts up from the set number and reaches the full count and returns to zero, the carrier output CA becomes L and the gate GA-9
, counter C of the measurement number counting circuit 5 via GA-10.
Load -1 and set the count to 11. As a result, an AUTO signal for starting measurement is generated at the output Qo. This AUTO signal is a signal indicating that automatic measurement is in progress, and acts as a command signal for permitting the integration circuit 2 to perform counting, for the measurement frequency circuit 5, and for canceling stoppage for the measurement flag circuit 6. Also, setting the count to 11 is 1 from now on.
This is to keep the AUTO signal constant until five measurements are completed by counting 2, 13, 14, 15, and 0. Then, after the power is turned on and the time set in the counter of the measurement interval control circuit 4 has elapsed, a measurement start signal is output. On the other hand, the flip-flop FF-1 of the measurement flag circuit 6 is cleared by the IT signal, and its output Q becomes L. Since the sample pan is in the standby position, limit switch WT
LS is open, and limit switches FWLS and BWLS are closed. Since the AUTO signal is inverted and applied to gate G-A, the gate is turned off and the output of gate G-2 becomes L. Therefore, gate G-3 is turned off,
The motor forward rotation relay FWD does not operate and continues in the standby position. Here, when the measurement start signal (ie, AUTO signal) is received, the prohibition of gate G-3 is released, the FWD is activated, the motor rotates forward, and the sample plate moves forward and enters the dryer. When the limit switch FWLS is pressed and opened at the forward end, the input of gate G-2 becomes day, and its output becomes L.
Gate G-3 is prohibited, relay FWD is inactivated, and the motor is stopped. On the other hand, due to the operation of the limit switch FWLS, the output of the negative input OR gate G-4 becomes "day", and the clearing of the delay counter C-2 is canceled via the inverter 1-1, and the free-running 2-second clock pulse generation circuit 7 Start counting the 2 second clock pulses output from the output Q of the oscillator B-1. This 2-second clock pulse is a pulse signal set mainly to regulate the integration time of the integration circuit 2, which will be described later.
When the count reaches 8 (one elapsed), the output Qo of the counter C-2 becomes the day, and the inputs of the gate G-5 both become the day, so its output becomes L. When the output QD becomes L at the 16th count (32nd sand elapsed), the output of the gate G-5 becomes 1, and the flip-flop FF of the measurement flag circuit 6
The output Q of -1 becomes day, and the output Q becomes L. Since limit switch BWLS is closed, gate G
-6 inputs are both turned on and relay BAK is turned on.
is activated, the motor reverses, and the sample pan begins to move backward. After the sample blood advances and stops in this way, after a certain period of time (32
The reason for retreating after the sand is to ensure that the sample is collected onto the sample pan during that time. The retraction of the sample dish closes the limit switch FWLS and clears the delay counter C-2. When limit switch BWLS is activated and opened at the backward end of the sample dish, gate G-6 is inhibited, relay BAK is deactivated, and the motor is stopped. At the same time, the delay counter C-2 is activated in the same way as when the limit switch FWLS was opened.
starts counting the output pulses of the 2-second clock generating circuit 7. When the counter C-2 counts 8 (one time has passed), its output Q. becomes day, and the output Q^ becomes L. On the other hand, limit switch BW is open, so 3-input NAND gate G-
Both inputs of 7 become days, and the output thereof becomes L to operate the switch circuit S-1, close the switch SW-1, and start integration. In other words, when the sample is crushed and the output of the measuring device 1 becomes sufficiently stable after one streak has passed, the integrating circuit 2
Begin integrating its output. When the counter C-2 counts 9 (one parent sand elapsed), outputs Q^, Q. At the end of the day, the input conditions of the three-input gate G-8 are satisfied and its output becomes "H". This output L is the M old SD signal and indicates that one measurement has been completed, and this M old SD signal resets the flip-flop FF-1 of the measurement flag circuit 6 through the gate G-9. Motor forward rotation relay FW
D is activated, the motor rotates normally again, and the sample dish begins to move forward. In addition, the M old SD signal enters the counter C-1 of the measurement number counting circuit 5, increments the count by 1, and counts 1.
It becomes 2. At the same time, the output Q^ of the counter C-2 becomes ``day'', the output of the gate G-7 becomes ``day'', and the switch SW-1 opens and the first integration ends. As the sample blood advances, the mitt switch BWB is closed and the counter C-2 is cleared again. While the sample dish is moving forward, open the standby limit switch WTB and close the gate G.
-A is input, but the motor does not stop because gate G-A remains inhibited by the AUTO signal.
That is, the counter C-1 is used for counting in the measurement circuit, and the counter C-2 is connected to the gates G-7 and G-8 and used for the integration circuit 2, measurement counting circuit 5, measurement flag circuit 6, etc. Each performs a counting operation to output an operation timing signal. The above operation is repeated, and the number of measurements is counted by the counter C-1 of the counting circuit 5. At the end of the fifth measurement, the count returns to 0, and the output Qo becomes L. As a result, gate G-A is inhibited by the AUTO signal, and when limit switch WT melon opens, gate G-A
The output of becomes L, and the output is passed through gate G-2 to gate G-3.
is prohibited, relay FWD is deactivated, and the sample pan is stopped at limit switch WTLS. Above 5
The integrated value of the measured values obtained by each measurement is compared with a comparison level in the comparator circuit 3. Three comparison circuits F-1, F-2, and F-3 are provided in the comparison circuit, and F-1 has the lowest comparison level and becomes the target value, while F-3 and F-2 have the lowest comparison level. A voltage dividing circuit including resistors R, , R2, and R3 is set vertically at a predetermined distance from each other so that the voltage is higher than 1. The integrated voltage is supplied to the inverting input of each comparator circuit by a voltage dividing circuit of R4, VR, and R5. Furthermore, the reference voltage that becomes each comparison level of the comparator circuit is set to a resistor VR by a rotary switch RS connected in series to a voltage dividing circuit of resistors R, R2, and R3.
This can be changed by changing the value of 2. That is,
To select and set the target water content, the user can change the entire level of each comparison circuit up or down by changing VR2 using the rotary switch RS.
Therefore, the voltage integrated by the integrating circuit 2 is compared by the comparing circuit 3, but as the integration progresses, the reference voltage is reached from the comparing circuits F-1 to F-2 and F-3 sequentially, and the integrated value When the voltage becomes higher than each reference voltage, the output of each circuit becomes L level. In this case, if the moisture content is high, up to F-3 will become L, but if the moisture content is low, F-3 or F-2 will not become L and will remain at day. For example, F-3 has a moisture content of 19% and becomes L.
F-2 becomes L at 18% and F-1 becomes L at 17%. The output of each comparison circuit is applied to the inputs B, C, and D of the counter C-3 of the measurement interval control circuit 4, and is loaded when the carry output CA of the counter C-1 of the measurement Muslim counting circuit 5 becomes L. Loaded into the count according to inputs B, C, and D. Counter C-3 is 8 minute clock pulse generation circuit B-2
count the pulses, and after reaching 15 counts, the carry output CA becomes L before the count reaches 0. For example, if the output of F-3 falls below 19% of the day, the count will be 8 and it will be 64 minutes, and if the output of F-3 and F-2 will be the day, the count will be 12.
It is loaded at 32 minutes and 16 minutes at count 14 on all days. Therefore, the time is set according to the moisture content at that time, and when the time elapses, the counter C-1 is loaded again by the carrier output CA and the next measurement is started. Next, when the moisture content reaches the target level or less, all outputs up to the comparator circuit F-1 become "day". F-1 at this time
The output (referred to as output COFF) is applied to the input port of the first-stage flip-flop FF-2 of the two-stage cutoff flag circuit 8, and is applied to the input port of the flip-flop FF-2 at the first stage of the two-stage cutoff flag circuit 8. FF-2
Activate the output Q and remember that the drying target has been reached. Next, the measurement is restarted 16 minutes later, and when the measurement is performed 5 times, if the integrated value is again less than the target value, the input D of the next stage flip-flop FF-3 of the two-stage cutoff flag circuit 8 Since the output COFF and the output Q of the first-stage flip-flop FF-2 are applied, the flip-flop FF-3 is operated by the carrier output CA of the measurement number counting circuit 5. Then, the fuel relay FUEL is activated by the L of the output Q, and the fuel is stopped. After a few minutes, timer B-
The gate G-11 is turned on by the L of the output Q in step 2, the blower relay FAN is activated, the blower is stopped, and the drying process is completed.
At the same time, the measurement interval control circuit 4 is cleared and the automatic measurement function is activated.
In other words, sequence control stops. Effects of the Invention As is clear from the above, according to the present invention, an appropriate waiting time can be set after the power is turned on by the measurement delay time setting section during the initial stage of drying when there is no particular need to carry out measurement, so that there is no need to waste measurement operations. In addition, it is possible to prevent contamination of the electrodes due to crushing of moisture-rich grains in the early stage of drying, and to perform accurate measurements. Moreover, since it is constructed using a measurement interval control circuit, the structure is simple.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing one embodiment of the present invention, and FIG. 2 is a block diagram of the circuit. DESCRIPTION OF SYMBOLS 1... Measuring device, 2... Integrating circuit, 3... Comparing circuit, 4... Measurement interval control circuit, 5... Measurement number counting circuit, 6... Measurement flag circuit, 7...・2-second clock pulse generation circuit, 8...Two-stage cutoff flag circuit, 9
...Stop circuit, 10...Measurement delay time setting circuit. Rudder map N ship

Claims (1)

[Claims] 1. A measurement unit that is attached to the dryer and measures the moisture content of the grain to be dried interposed between the electrodes and outputs a measurement value signal corresponding to this moisture content value, and a target moisture content setting section that outputs a target value signal, a comparison section that compares the measured value signal and the target value signal and outputs a comparison signal according to the difference, and a time interval according to the comparison signal. a measurement interval control section that outputs a measurement command signal to the measurement section when the moisture content of the grain to be dried reaches a target moisture content value, and outputs a stop signal for the dryer operation based on the output of the comparison section. The stop section and the time interval from the start of operation of the dryer to the start of the first measurement of the moisture content value are arbitrarily set variably using a manual switch, and the measurement delay signal is given priority over the comparison signal at the start of the operation to perform the measurement. 1. An automatic moisture content measurement device for a dryer, comprising: a measurement delay time setting section for outputting to an interval control section and delaying the start of the first measurement.