JPS6353459A - Abnormality detector for moisture meter - Google Patents

Abstract

PURPOSE:To assure the detection of abnormality in a moisture meter immediately before the start of moisture measurement, by detecting abnormality of the moisture meter in linkage with the reversion of a moisture meter motor. CONSTITUTION:A moisture measuring section 1 is provided with a grain particle supply mechanism which supplies grain particles between electrode rolls 2 and 2 one at each specified time and a resistance-voltage conversion circuit 3 converts a resistance between the rolls 2 and 2 into a voltage. When a reversion signal is fed to a motor driving circuit 10 from a microcomputer 5, a moisture meter motor 11 is reversed to start the discharging of grain with husk or the like. The reversion signal is fed to a switch selector circuit 6 to change a mobile contact of a selector switch 4 over to the contact (a) position. The computer 5 samples a reference voltage from a reference voltage generating section 7 to determine the presence of abnormality in an input circuit of the moisture meter and the results of the determination are shown on a display 13 while moisture measurement is stopped in case abnormality is found. This assures the detection of abnormality in the moisture meter immediately before the start of moisture measurement.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a moisture meter installed in a grain dryer or the like to measure the moisture content of grains during drying, and particularly to a moisture meter that measures the moisture content of each grain. Concerning improvements to particle-type moisture meters.

(Conventional Technique n#i) This type of single-drop type moisture meter has a pair of 4III standard electrode calls and this 7I! , and a grain feeding mechanism called a feed roll that feeds grains one grain at a predetermined interval between pole rolls. Then, when grains are taken out from the dryer and fed between the electrode rolls by this grain supply mechanism, the Ti and polar coal crush them, converting the resistance between the electrode rolls into voltage and measuring the moisture content. conduct.

(Problems to be Solved by the Invention) By the way, when this type of moisture meter is used in a grain dryer, there is a drawback that moisture is measured multiple times during the drying period, and an abnormality in the moisture meter cannot be detected each time the moisture is measured. Yes, reliability was low.

On the other hand, when performing the moisture A111 determination using the moisture meter, the motor must be reversed for a predetermined period immediately before the 311 determination starts.
The adhering grains on the electrode roll and the remaining grains on the feed roll are removed to eliminate the adverse effects of the previous Jilt determination.

Therefore, the purpose of the present invention is 1. By paying attention to these points and detecting an abnormality in the moisture meter in conjunction with the reverse operation of the moisture meter motor, it is possible to detect an abnormality in the moisture meter immediately before the moisture δ11 constant starts, thereby making it possible to detect the moisture meter's 4g The goal is to significantly improve reliability.

(Means for Solving the Problems) In order to achieve the above object, the present invention reverses the motor that drives the electrode roll during a predetermined period immediately before the start of moisture measurement, and after the elapse of the predetermined period, the motor a moisture measuring means A that rotates in the normal direction to crush the grains with the electrode roll and determines the moisture content; a signal switching means C that switches to and outputs the base signal from the means B; and the signal switching means C
The apparatus is equipped with abnormality detection means for detecting whether the output reference signal is a predetermined value or not, and outputting an abnormal signal when the value is not the predetermined value.

(Function) As shown in FIG. 1, in the present invention, when the motor that drives the electrode roll in the moisture measuring means A reverses, the signal switching means C changes the reference signal from the reference signal generating means B in conjunction with the reverse rotation. The signal is switched and output according to the abnormality detection means.

The abnormality detection means detects whether or not the reference signal is a predetermined value (if), and outputs an abnormal signal when the reference signal is not a predetermined value.

(Example) FIG. 2 is a diagram of the first embodiment of the present invention.

In the figure, 1 is a moisture measuring section that measures the moisture content of grains, and a pair of electrode rolls 2.2 for measurement, and grains are fed one by one at predetermined time intervals between the electrode rolls 2, 2. and a grain t1'l supply mechanism (not shown). 3 is a resistance-voltage conversion circuit, which crushes the grains supplied between the electrode rolls 2 and 2 and converts the resistance between the electrode rolls at that time into voltage.

4 is a changeover switch, and when a reversal signal of the microcomputer 5 and the moisture meter motor 11 is supplied to the switch changeover circuit 6 at a predetermined timing as described later, its movable contact switches to the resistance-voltage conversion circuit 3 side. The contact A is switched from the contact a to the reference voltage generating section 7 side, and the output voltage from the reference voltage generating section 7 is A/D converted by the A/D conversion circuit 8 and supplied to the microcomputer 5. This changeover switch 4 is preferably configured with a relay contact or the like.

Reference numeral 9 denotes a rise detection circuit that detects the rise of all constant voltages output from the resistance-voltage conversion circuit 3. The output of this rise detection circuit 9 is supplied to the microcomputer 5, and the current state is displayed on the display 13 as described later. Jllllll of
l Used to count whole grains.

The microcomputer 5 makes various judgments as shown in FIG.
Control. 10 is a motor drive circuit that drives the moisture meter motor 11, and 12 is a display drive circuit that drives the display 13. The display 13 is preferably made of a seven-segment display element.

Next, the abnormality detection operation of the first embodiment configured as described above will be explained with reference to FIGS. 3 and 4.

Now, as shown in FIG. 4, at time L1 prior to the start of moisture measurement, when a reverse rotation signal is sent from the microcomputer 5 to the motor drive circuit 10, the moisture meter motor 11 is rotated in the reverse direction (step S1), This causes the electrode roller 2.2 to reverse direction and to begin removing the adhered grains etc. that were crushed during the previous measurement.

Further, since the reversal signal is sent to the switch changeover circuit 6, the movable contact of the changeover switch 4 is switched to the contact a side (step S2), and at time L2 after waiting for a certain period of time in step S3, , as shown in FIG. 4, the supply voltage V output from the reference voltage generation section 7 and supplied to the A'/D conversion circuit 8 rises.

Next, at time t3, the reference voltage from the reference voltage generator 7 is sampled (step S4), and it is determined whether or not the value obtained by this sampling is abnormal (step S5).
That is, in step S5, it is determined whether the value obtained by sampling is within a predetermined tolerance range, and if it is outside the tolerance range, the number of abnormalities is incremented by 1 in step S6, and the added value of the number of abnormalities is It is determined whether the number of times n exceeds a predetermined number (step S7).

For example, as shown in FIG. 4, the reference voltage is sampled at times t3, t4, and E5, and if the values obtained by sampling are abnormal all three times (step 54
~S7), and proceeds to step S8. In step S8, a message indicating that the input circuit of the moisture meter is abnormal is displayed on the display 13.
For example, the display as shown in FIG.
Step S9).

On the other hand, if the sampling value is within the allowable range and normal in step S5, a display indicating that the input circuit of the moisture meter is normal is displayed on the display device 3, for example, as shown in FIG. 5 (A). (step 510).

Thereafter, as shown in FIG. 4, at time t6, when the microcomputer 5 sends a forward rotation signal to the motor drive circuit 10, the moisture meter motor 11 rotates forward (step 5ll), and the electrode roller 2 2 rotates forward, the movable contact of the changeover switch 4 switches to the contact side, and moisture measurement starts (step 512).

By the way, in this embodiment, the moisture meter motor 11 rotates in the normal direction, which causes the electrode roller 2.2 to rotate in the normal direction to measure the moisture content.For example, 33 grains are measured one grain at a time every 4 seconds. Since the moisture content is being measured, if the display 13 displays the number of grains currently being measured, for example '12' (
(See (B) in FIG. 6), this is extremely convenient because the operator can easily grasp the operating status of the moisture meter. Furthermore, during the period when no moisture measurement is performed, if the previously measured moisture value is displayed on the display 13 as, for example, ``17.4'' (see (A) in Figure 6), It is convenient for the workers.

FIG. 7 is a block diagram of a second embodiment of the present invention.

In this second embodiment, the reference voltage generating section 7 of the first embodiment shown in FIG. , select one of the moisture measuring section 2 and the reference resistor 14 with the changeover switch 4, and connect the resistance-voltage conversion circuit 3.
This allows electrical connection to be made. Note that the configuration other than the above is the same as the first embodiment, so
The same reference numerals are indicated by ζj, and detailed explanation thereof will be omitted.

In the second embodiment constructed in this way, as shown in FIG. The movable contact of the changeover switch 4 switches to the contact a side and performs the same operation as the example of operation shown in FIG. Since abnormality detection of the moisture meter is performed in conjunction with the reverse operation, abnormality detection of the moisture meter can always be detected immediately before the start of moisture measurement, and the reliability of the moisture meter can be significantly improved.

[Brief explanation of drawings]

FIG. 1 is a functional diagram of the present invention, FIG. 2 is a block diagram of the first embodiment of the present invention, FIG. 3 is a flowchart showing an example of its operation, FIG. 4 is a diagram showing an example of its operation, and FIG. Figure and 6th
Each figure shows an example of a display on a display, and FIG. 7 is a block diagram of a second embodiment of the present invention. A is a moisture measuring means, B is a reference signal generating means, C is a signal switching means, and D is an abnormality detecting means. Patent applicant: Iseki Agricultural Machinery Co., Ltd. Representative: Tobe Maki (and 2 others) Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] A motor that drives an electrode roll is rotated in reverse during a predetermined period immediately before the start of moisture measurement, and after the elapse of the predetermined period, the motor is rotated in the normal direction, thereby crushing grains with the electrode roll. moisture measuring means for measuring moisture content; signal switching means for switching the measurement signal from the moisture measuring means to a reference signal from the reference signal generating means and outputting the same in conjunction with the reverse rotation of the motor; 1. An abnormality detection device for a moisture meter, comprising abnormality detection means for detecting whether or not a reference signal switched and outputted by means is a predetermined value, and outputting an abnormal signal when the reference signal is not the predetermined value.