JPH0518032B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a control device for a grain drying device, and in particular, when there is an abnormality in the temperature detection means for detecting grain temperature, it is possible to safely dry the grain. This invention relates to a control device for a grain drying device that continues to operate.

[Conventional technology]

Conventionally, grain drying equipment has been equipped with a grain moisture measuring device that measures the moisture content of the grain in order to ascertain the degree of dryness. Based on the output of this grain moisture measuring device, the moisture content is determined as the target moisture content. is controlled.

This grain moisture content measuring device is provided with a pair of rotating electrode rolls. Grain is fed between these electrode rolls and crushed. After that, a constant voltage is applied to a pair of electrode rolls, and the voltage that changes depending on the electrical resistance of the crushed grain is measured to measure the moisture content of the grain. In other words, when the moisture content of the grain is low, the electrical resistance of the grain increases, and when the moisture content of the grain is high, the electrical resistance of the grain decreases. I am trying to measure the moisture content.

However, the electrical resistance of grains changes with temperature and decreases as the temperature increases. Therefore, as the temperature increases, the measured voltage value decreases, and the measured moisture content becomes larger than the actual moisture content as the temperature increases. In this way, the electrical resistance of crushed grain changes depending on the temperature even if the moisture content is the same, so conventional methods either detect the outside air temperature near the grain moisture content measuring device and convert it to grain temperature. Grain temperature is directly detected, and the output of the grain moisture content measuring device is corrected by grain temperature to calculate grain moisture content. For example, when grain temperature increases by 1°C, grain moisture content is reduced by 0.1%. Then, when this grain moisture content reaches the target moisture content set in the grain drying device, drying of the grain is completed.

On the other hand, if there is an abnormality in the detection means that detects the grain temperature, the pump that supplies fuel to the burner that generates hot air will be stopped and the burner will be extinguished to prevent the grain from becoming overly dry. It's summery.

[Problem that the invention seeks to solve]

However, in conventional grain drying equipment, if there is an abnormality in the outside air temperature or the detection means that detects the grain temperature near the grain moisture content measuring device, the fuel supply to the burner that generates hot air to dry the grain is interrupted. Since the pump for use in the drying process is stopped and the burner is extinguished, there are problems in that the drying operation is hindered and the drying efficiency is deteriorated due to the interruption of the drying operation.

The present invention has been made in order to solve the above-mentioned problems, and provides a control device for a grain drying device that safely continues drying the grain even if there is an abnormality in the detection means for detecting grain temperature. The purpose is to

[Means for solving problems]

In order to achieve the above object, the present invention corrects the measured value of a grain moisture content measuring device based on the detected temperature detected by a temperature detection means that directly or indirectly detects the grain temperature, and calculates the moisture content. In a control device for a grain drying device, the control device operates the grain drying device so that the moisture content reaches a target moisture content, and stops the operation of the grain drying device when the moisture content reaches the target moisture content. abnormality detection means for detecting whether or not the detection means has become abnormal; and correction for making the detected temperature a constant value and increasing the target moisture content by a predetermined value when the abnormality detection means detects an abnormality. It is constructed by comprising means and.

[Effect]

According to the present invention, when there is an abnormality in the temperature detection means that directly or indirectly detects the temperature of dried grains, the detected temperature is fixed at a constant temperature and the measured output of the grain moisture meter is corrected. At the same time, the target moisture content is increased by a predetermined value. Thereby, grain drying can be completed at a grain moisture content higher than the target moisture content. Therefore, if there is an abnormality in the temperature detection means, drying can be continued without over-drying the grain.

〔Example〕

An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a schematic diagram of the grain drying apparatus.

The grain moisture content measuring device 10 is arranged near the grain conveying bucket conveyor 12 of the grain drying device. A pair of electrode rolls 16 are provided in this grain moisture content measuring device 10 . Electrode roll 16
is made of a conductive metal material, and is formed of a substantially disk-shaped detection section 18 and a shaft section 20 that protrudes from the center of the detection section 18 toward one side in the axial direction.

As shown in FIG. 2, the surrounding wall 9 of the detection unit 18
0 is knurled, and furthermore, a spiral groove 92 and an arcuate notch 94 extending over about 1/4 of the circumference are formed. The electrode roll 16 is inserted into the case 22 and pivoted,
It is designed to rotate around the shaft portion 20. The case 22 has a through hole 2 for supporting the electrode roll 16 in the center.
The shaft portion 20 of the electrode roll 16 is inserted into the through hole 24 of an insulating member in which a pair of holes 4 are bored, and the shaft portion 20
2 ball bearings on the front and rear respectively
It is designed to be pivoted via 6.

Conductive contact terminals 28 are sandwiched between each ball bearing 26 that supports the electrode roll 16, and the contact terminals 28 come into contact with the shaft portion 20 of the electrode roll 16. There is.

In addition, the ball bearing 26 allows the case 2 to
Gears 14 are coupled to the tip of a shaft portion 20 of an electrode roll 16 which is pivotally supported by the electrode roll 2 in a mutually meshing state. Therefore, as the gear 14 rotates, the electrode rolls 16 rotate in opposition to each other.

The connecting portion between the gear 14 and the shaft portion 20 is made of an insulator. Therefore, even after the electrode roll 16 and gear 14 are combined and integrated, they remain non-conductive.

A gear (not shown) meshes with the gear 14, and this gear is pivotally supported by an output shaft of a drive motor (not shown). Therefore, the driving force of the drive motor is transmitted to the gear 14, and together with the gear 14, the electrode rolls 16 are rotated so as to face each other. Therefore, when grains are fed between the electrode rolls 16, the grains are crushed by the electrode rolls 16.

On the other hand, the electrode roll 1 of the grain moisture content measuring device 10
A moisture measuring thermistor 30 for detecting the temperature of the sampled grain (hereinafter referred to as grain temperature) is provided above the grain temperature.

The contact terminal 28 and the moisture measuring thermistor 30, which are placed in contact with the shaft portion 20 of the electrode roll 16, are connected to a control circuit 32.

The control circuit 32 includes a central processing unit (CPU) 34,
It is configured to include a read-only memory (ROM) 36, a random access memory (RAM) 38, an input port 40, an output port 42, and a bus 44 such as a data bus or a control bus that connects these. A contact terminal 28 and a moisture measuring thermistor 30 are connected to the input port 40 via an analog-digital (A/D) converter 46 and a multiplexer 48, respectively, and a moisture setting device for setting the target moisture content of the grain. A dial 50 is connected. In addition, the output port 42
An indicator 54 made of a light emitting diode (LED) or the like displays grain moisture content or an abnormality in the moisture measuring thermistor 30 via a drive circuit 52.
is connected thereto, and an electromagnetic pump 58 for supplying fuel to a burner that generates hot air is connected via a drive circuit 56. In addition, the output port 42
A motor of a grain conveying machine 62 and the like are connected to the grain conveying machine 62 via a drive circuit 60.

The operation of this embodiment configured as above will be explained. FIG. 3 shows the control routine of this embodiment. When the grain drying operation is started and the grain moisture content measurement is started, it is determined in step 100 whether the flag f, which is set when the moisture measuring thermistor 30 is abnormal, is 1 or not. When there is no abnormality in the thermistor 30 for moisture measurement, the flag f is 0, so the grain temperature T is read from the thermistor 30 for moisture measurement in step 102, and in step 104, the thermistor 30 for moisture measurement is abnormal (broken wire, short). etc.) is determined. To detect an abnormality in the moisture measurement thermistor, for example, read the grain temperature from the moisture measurement thermistor, calculate the difference between the grain temperature read last time and the grain temperature read this time, and calculate the amount of change in grain temperature. and determine whether the amount of grain temperature change is within a predetermined range. In this way, if the moisture measurement thermistor is abnormal, an abnormally high grain temperature (during shoot) or abnormally low grain temperature (during wire breakage) will be read compared to the grain temperature read previously, and the grain temperature will be The amount of change increases. Therefore, if the amount of grain temperature change falls outside the predetermined range, it can be determined that the moisture measuring thermistor is abnormal. Alternatively, the grain temperature may be read from the moisture measuring thermistor to determine whether the grain temperature from the moisture measuring thermistor is within a normal grain temperature change range. In other words, if the moisture measurement thermistor is abnormal, a grain temperature that is abnormally higher or lower than the normal grain temperature from the grain temperature at the start of the grain drying operation to the grain temperature at the end of the grain drying operation will be read. It will be done. Therefore, if the grain temperature is outside the normal grain temperature range, it is determined that the moisture measuring thermistor is abnormal.

If it is determined in step 104 that the moisture measuring thermistor 30 is abnormal, the flag f is set to 1 in step 106, the flag f is set to 1 in step 108, and the grain temperature T is set to the fixed temperature ( For example, the temperature is fixed at 20℃).

If it is determined in step 104 that the moisture measuring thermistor 30 is not abnormal, the flag f is cleared in step 109.

Then, in step 110, the voltage value R of the grain is read from the grain moisture content measuring device 10, and in step 112, the moisture content G is calculated based on the voltage value R and the grain temperature T. In step 114, the set moisture content S is read from the moisture setting dial 50.

In step 116, it is determined whether the flag f is 1 or not. If the flag f is determined to be 1, the abnormality is displayed in step 118 as shown in FIG. 4, and the grain moisture content calculated in step 112 is displayed. and the rate are alternately displayed on the display 54. step 120
In step 114, the set moisture content S read has a pre-stored constant α (for example, the grain temperature
1.0% (equivalent to ℃) will be added. That is, when the moisture measuring thermistor 30 is abnormal, the abnormality is displayed on the display 54 and the set moisture content S
is set to a higher value than the moisture content S set from the moisture setting dial 54.

If it is determined in step 116 that the flag f is not 1, in step 122 the grain moisture content calculated in step 112 is displayed on the display 54,
The process moves to step 124.

In step 124, it is determined whether the grain moisture content G calculated in step 112 is greater than the set moisture content S. If the grain moisture content is greater than the set moisture content S, the drying operation continues at step 126.

In step 124, the moisture content G is set as the moisture content S.
If the following is determined, in step 128, the electromagnetic pump 58 for supplying fuel to the burner that generates hot air is turned off, and then the motor of the grain conveyor 62 is turned off, and the drying work is completed. .

If the moisture measurement thermistor that detects the temperature of dried grain becomes abnormal as described above, the temperature detected by the moisture measurement thermistor is fixed at a constant temperature, the grain moisture content is calculated, and the moisture content of the grain is Since grain drying can be ended at a grain moisture content higher than the set moisture content, it is possible to minimize grain drying stop time due to malfunction of the moisture measuring thermistor.

Incidentally, an abnormality in the moisture meter thermistor may be indicated by a lamp, a buzzer, or the like.

In addition, when detecting grain temperature, in the case of a method that detects the outside air temperature near the grain moisture content measuring device and converts it into grain temperature, if there is an abnormality in the detection means for detecting outside air temperature, The detected temperature is fixed and grain drying is completed at a grain moisture content higher than the set moisture content as described above. In addition, in the case of a method in which grain temperature is detected by a moisture measuring thermistor and if the moisture measuring thermistor is abnormal, the outside air temperature is converted to grain temperature, the moisture measuring thermistor and the outside air temperature are When both of the detecting means are abnormal, the detected temperature is fixed and grain drying is completed at a grain moisture content higher than the set moisture content as described above.

〔Effect of the invention〕

As explained above, according to the present invention, if there is an abnormality in the detection means that directly or indirectly detects the temperature of dried grains, drying can be continued without overdrying the grains. So,
The effect is that the interruption time due to an abnormality in the detection means can be minimized.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing a grain drying device according to an embodiment of the present invention, Fig. 2 is a perspective view showing an electrode roll of a grain moisture content measuring device, Fig. 3 is a flow chart showing a control routine, and Fig. 4 is an explanatory diagram showing a display of an abnormality. 10...Grain moisture content measuring device, 30...Moisture measuring thermistor, 32...Control circuit.

Claims (1)

[Claims] 1 Correct the measured value of the grain moisture content measuring device based on the detected temperature detected by the temperature detection means that directly or indirectly detects the grain temperature to determine the moisture content, and make sure that the moisture content reaches the target moisture content. In a control device for a grain drying device that operates the grain drying device so that the moisture content reaches a target moisture content and stops the operation of the grain drying device, the control device detects whether or not the temperature detection means becomes abnormal. An abnormality detection means for detecting an abnormality, and a correction means for setting the detected temperature to a constant value and increasing the target water content by a predetermined value when an abnormality is detected by the abnormality detection means. Control device for grain drying equipment.