JP3358198B2 - Overload detection method of motor for grain dryer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting an overload of a motor for a grain dryer .

[0002]

2. Description of the Related Art Conventionally, for example, in a motor used for a grain dryer, a current value of the motor is detected by a current transformer, and a detected current value is detected to be equal to or more than a reference rated current value for a predetermined time or more. And the motor is an overload detection system in which stop control is performed.

[0003]

For example, grains stored in a grain storage chamber of a grain dryer for drying grains are moved from the storage chamber through the grain drying chamber by rotating a valve.
While being fed down, the hot air passes through the drying chamber, and the grains flowing down are exposed to the hot air and dried.

[0004] During the drying, the current value of the motor for rotating and driving the delivery valve is detected by a current transformer, and the load state of the motor is detected. If a large amount of straw chips or the like is mixed in the grains during drying, the straw chips may wind around the delivery valve, and the winding causes the motor of the motor that drives the delivery valve to rotate. The load fluctuates, the motor is overloaded, and the time until the stop of the motor is added due to the overload. When the added time passes a set predetermined time, the motor is controlled to stop. The dryer is controlled to stop to stop the drying of the grain, but the straw scraps wrapped around the delivery valve are removed during rotation, and the overload of the motor returns to the standard rated current value within a predetermined time. In such a case, the stop processing of the motor is not performed, and the added time until the stop is cleared .

[0005] Especially in grain dryers, especially grain transport systems
If the motor stops, drying will occur due to stagnation of the transport kernels.
It is necessary to stop control without any cause,
Is not a good idea.

[0006]

SUMMARY OF THE INVENTION The present invention circulates kernels.
To drive the grain conveyor of the grain dryer while drying
Current values of the motors 4b and 4d
The lances 39b and 39d are provided and the load current
And measure the reference rated current value set for this motor.
Calculate the overload ratio based on the ratio to the constant current value, and
The time constant set in advance to be large or small based on the rate
Cumulative time exceeds predetermined value by adding sequentially at intervals
It is determined whether the motors 4b and 4d need to be stopped based on whether
The current transformers 39b and 39d are
The overload of each motor 4b, 4d is detected and the above time constant
In the middle of adding
Is detected for more than a predetermined time,
Processing time is cleared by the processing means, and
If the detection below the flow value is less than the specified time, the previous accumulated time
The overload detection method of the grain dryer motor is characterized by continuing the addition of

[0007]

According to the present invention, a grain transport system is provided.
Current values of the motors 4b and 4d
b, 39d, and the detected measured current value and
The overload ratio is calculated based on the ratio with the set reference rated current value.
And the calculated overload ratio determines
The set time constant is sequentially added at the specified time intervals.
When the accumulated time of the time constant exceeds a predetermined value,
The motor outputs a stop signal.
However, during this cumulative time addition process,
If the measured current value is less than or equal to the reference
If it continues above, this total time will be cleared and
Even if post-overload is detected, it is added to the previous cumulative addition time.
No, it will be processed newly.
The motors 4b and 4d stop immediately due to overload.
Troubles are eliminated.

[0008] Naturally, the current is kept below the rated current value for a predetermined time.
Overload of each part driven by the motor
After the cause has been resolved and the time has stabilized, the cumulative total
Time will be cleared, so the grain of the grain dryer
This is effective for a motor in which the load of the transfer greatly varies.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. The figure shows a circulation type grain dryer 1 for drying grains.
A moisture sensor 2 for detecting the moisture in the grains, a burner 3 for generating hot air, and motors 4a, 4b for rotating and driving the respective components.
, Etc. are shown.

The dryer 1 is provided with a transfer trough 6 and a ceiling plate 7 in which a transfer spiral is rotatably mounted above a machine wall 5 in a rectangular shape which is long in the front-rear direction, and a grain is provided below the ceiling plate 7. A grain storage chamber 8 for storing grains is formed. Grain drying room 9,
9 is an exhaust chamber 1 on both the left and right sides below the storage chamber 8.
0, 10 and a central blower chamber 11, and a feed valve 1 for feeding and flowing down grains at the lower part of the drying chambers 9, 9.
2 are rotatably supported.

The grain collecting gutter 13 rotatably supports a transfer spiral, and is provided below the drying chambers 9 and 9 so as to communicate with each other. The burner 3 is provided inside a burner case 14, and the burner case 14 is detachably provided on an outer surface of the machine wall 5 at a front side of the machine wall 5 so as to correspond to an inlet side of the blower chamber 11. An operating device 15 for starting and stopping the burner 3, the moisture sensor 2 and the dryer 1 for each of the work of inserting, drying and discharging is detachably provided on the front wall 5 of the machine.

An exhaust fan 16 is provided on the rear wall 5 on the rear side of the rear wall 5 at the center rear side of the exhaust path chamber 17 provided to communicate with the left and right exhaust chambers 10 on the rear wall 5. On the side wall 5, there is provided an exhaust motor 4 a for driving the exhaust 16 to rotate. Reference numeral 4b denotes a valve motor, which is one of the grain conveying systems, for rotating the delivery valves 12, 12 via a speed reduction mechanism.

The fuel pump 19 has a fuel valve,
The fuel pump 19 sucks the fuel in the fuel tank 20 and supplies it to the burner 3 by opening and closing the fuel valve. The blower 21 is provided on the outer side of the upper plate, and is driven for speed change by the blower motor 4c for speed change, and the combustion air corresponding to the supplied fuel amount is blown to the burner 3 by the blower 21.

The diffusion board 22 is provided at a central portion in the front-rear direction of the bottom plate of the transfer gutter 6 and below the supply port for supplying the transfer kernels to the storage chamber 8, and the kernels are uniformly diffused into the storage chamber 8. Is being reduced. The grain raising machine 23 is provided outside the front side of the machine wall 5 and has a belt with a bucket conveyor 24 stretched inside. The upper end is provided with a discharge cylinder 25 between the transfer gutter 6 and the start end. The lower end is provided with the grain collecting gutter 13
A supply gutter 26 is provided and communicated with the terminal end.

Reference numeral 4d denotes a motor for a grain raising machine which is one of the grain transport systems . The belt with the bucket conveyor 24, the transfer spiral in the transfer gutter 6, the diffusion plate 22, and the grain collection gutter. The driving spiral and the like in 13 are driven to rotate.
The moisture sensor 2 is provided substantially at the center in the vertical direction of the grain raising machine 23. The moisture sensor 2 is provided with a motor 4e for moisture by transmitting an electric measurement signal from the operating device 15.
Are rotated to drive the respective parts of the moisture sensor 2 so as to receive the grains falling while being transported upward by the bucket conveyor 24, and detect the moisture of the crushed grains while clamping and crushing the grains. Let me.

The operating device 15 has a box shape and a motor 4 for the air blower of the dryer 1
a, a start switch 27 for starting the motor 4b for the valve, the motor 4c for the blower, the motor 4d for the grain-raising machine, the motor 4e for the moisture, and the like for each of the operations of drying and discharging; A stop switch 28 for performing a stop operation,
Moisture setting knob 29 for setting the finishing target moisture of the grain by the operation position, grain type setting knob 30 for setting the hot air temperature generated from the burner 3 by the operation position, and inset amount setting knob 31, various display items , A display unit 32 for digitally displaying the data, a monitor display, and the like.

The control device 33 is provided in the operation device 15 and is a processing means for processing the addition processing time of each of the motors 4a, 4b... Are provided in the operating device 15, and the detected values of the power transformers 34, 34...
5, input to a control microcomputer 38 via a comparison circuit 36 and a digital input circuit 37;
Operation of the stop switches 27 and 28 and the setting knobs 29 and
The operations of 30 and 31 are input to the control microcomputer 38 via the digital input circuit 37. The current transformers 39a, 39b, 39c, 39d for exhaust fans, valves, blowers, grain-raising machines, and moisture detectors detect the current values of the motors 4a, 4b... At predetermined time intervals .
39e is provided in the operation device 15, and the detected values of the current transformers 39a, 39b.
0, an amplifying circuit 41, an analog input circuit 42, and an A / D conversion circuit 43, which are input to the control microcomputer 38.
, And the detection values of the moisture sensor 2 and the hot air temperature sensor 44 are input to the control microcomputer 38 via the analog input circuit 42 and the AD conversion circuit 43. I have. The various input values input to the control microcomputer 38 are subjected to arithmetic and logical operations and comparison operations, and the output circuits 45 which receive and output various commands from the control microcomputer 38 are output to the respective motors 4a. , 4b... Control the start and stop of the fuel pump 19 and the like.
, Various items are displayed on the display unit 32.

The control microcomputer 38 stores the reference rated current value of each motor 4a, 4b.
As shown in FIG. 6, the overload rate α is calculated by the detected current value / the reference rated current value for each of HZ and 50HZ, and the overload rate α is detected as overload when the overload rate is 1.1 or more. The relationship between the overload rate α and the time constant β is set and stored, for example, as shown in FIG.

Each of the motors 4 by the control device 33
The overload control of the current values a, 4b... is performed as follows. That is, the motors 4a, 4b...
The operation output is turned on (step 101), and the operation output is turned on for a predetermined time (T
1) It is detected whether or not the time has elapsed (step 102). If NO, the process returns to (step 101). If YES, the current values of the motors 4a, 4b... Measured by the current transformers 39a, 39b. Loaded (step 1
03), an overload rate α is calculated based on the read measured current value and the reference rated current value set and stored (step 104), and the calculated overload rate α and the set overload rate 1.1 are calculated. Are compared to detect if α ≦ 1.1 (step 105), and if YES, the stop reset counter is counted up (+1) (step 106), and the stop reset counter is set to a fixed value N. Is detected (step 107), and if YES is detected, the stop counter is cleared (step 108), and then the stop reset counter is cleared (step 10).
9) It is detected whether a predetermined time (T2) has elapsed (step 110). If YES is detected, the process returns to (step 103). If NO is detected, the process returns to (step 110).
If NO is detected in (Step 107), the process proceeds to (Step 110) without going through (Steps 108 and 109).

If NO is detected in step 105, the stop reset counter is cleared (step 11).
1) Subsequently, a process of adding a time constant to the stop counter is performed (step 112), and the stop counter is compared with a constant (K) to detect whether stop counter ≧ K (step 113), and NO Is detected (step 11
0), and if YES is detected, the motors 4a,
4b are stopped (step 114).

As shown in FIG. 6, the time until the motors 4a, 4b... Stop based on the overload rate α and the time constant β is calculated as follows. Elapsed time (T2)
Is set and stored, for example, as 0.2 sec, and the constant (K) is set and stored as 24000. For example, if the overload rate α is as follows, the overload rate α> 3.
Stops when 0 is detected 10 times. The calculation of the time until the motor stops is calculated as 0.2 × 24000/2400 = 2 sec.

For example, if the overload rate α is as follows, the operation stops when the overload rate 1.5 <α ≦ 2.0 is detected 300 times. The calculation of the time until the motor stops is 0.2 × 2
It is calculated that 4000/80 = 60 sec. Hereinafter, the operation of the above embodiment will be described. Operation device 15
By operating the setting knobs 29, 30, and 31 to predetermined positions and operating the start switch 27 for starting the drying operation, the motors 4a, 4b,... Of the grain dryer 1 are started. Each part of the dryer 1, the burner 3, the moisture sensor 2, and the like are started, and hot air is generated from the burner 3.
The air is sucked and exhausted by the exhaust fan 16 through the exhaust passages 0 and 10 and the exhaust passage chamber 17.

The grains stored in the grain storage chamber 8 are dried by being exposed to the hot air while flowing down from the storage chamber 8 through the drying chambers 9, 9. It is fed to the lower part, flows down and is fed from the grain collecting gutter 13 through the supply gutter 26 into the grain raising machine 23 by the lower transfer spiral, is conveyed to the upper part by the bucket conveyor 24, and is conveyed through the ejection cylinder 25. The water is supplied into the gutter 6, transferred and supplied from the transfer gutter 6 onto the diffusion plate 22 by an upper transfer spiral, and is evenly diffused and reduced into the storage chamber 8 by the diffusion disk 22, circulated and dried, and then subjected to the moisture sensor. When the grain moisture detected by 2 detects the same grain moisture as the finish target moisture set by operating the moisture setting knob 29, it is detected that the drying has been completed, and the control device 33 automatically controls the grain moisture to detect the moisture. The dryer 1 is automatically stopped, and the drying of the grain is stopped.

During this drying operation, the power supply transformer 34 detects whether the frequency of the main power supply is 60 HZ or 50 HZ.
Further, for example, when straw chips or the like are wound around the delivery valves 12, 12, a current transformer 39 for measuring a current value of a valve motor 4 b that rotationally drives the delivery valves 12, 12.
b, the measured current value becomes larger than the reference rated current value set and stored, the overload rate α is calculated from the measured current value and the reference rated current value, and the calculated overload rate α is calculated. Is greater than or equal to the set overload rate, a time constant until the motor 4b is stopped is added by the overload rate α, and when the added total number of hours elapses, the stop control of the motor 4b is stopped. Then, the dryer 1 is automatically stopped, and drying of the grain is stopped.

During the operation within the cumulative number of hours to which the time constant has been added, the straw chips wound around the delivery valves 12, 12 are removed, and the measured current value measured by the current transformer 39b is changed to the reference rated current. If the value below the value is continuously measured for a predetermined time or longer, the total number of hours with the time constant added is cleared.
Is A controlled drying of grains is continued.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of the present invention.

FIG. 1 is a block diagram.

FIG. 2 is a flowchart.

FIG. 3 is a partially broken whole side view of the grain dryer.

FIG. 4 is an enlarged sectional view taken along the line AA of FIG. 3;

FIG. 5 is a partially broken front view of a grain dryer.

FIG. 6 is a standard rated current value of each motor.

FIG. 7 is a relationship diagram between an overload rate α and a time constant β.

[Explanation of symbols]

 4a Motor for blower 4b Motor for valve 4c Motor for blower 4d Motor for grain riser 4e Motor for moisture 39a Current transformer for blower 39b Current transformer for valve 39c Current transformer for blower 39d Grain riser Current transformer for machine 39e Current transformer for moisture

Claims (1)

(57) [Claims] 1. A grain dryer for drying while circulating grains.
A motor 4b rotated to drive the grain conveyor of
Current transformers 39b and 39d are provided for the current value of 4d.
To measure the load current at predetermined time intervals and set this motor.
Due to the ratio between the reference rated current value and the measured current value
Calculate the load factor and set it in advance based on the overload factor
The time constants are sequentially added at the predetermined time intervals.
The motors 4b, 4b depend on whether the accumulated time exceeds a predetermined value.
d to determine the necessity of stopping the current
The lances 39b and 39d are overloads of the motors 4b and 4d.
During the addition process of the above time constant
It is necessary to continuously detect the value equal to or less than the
By using the processing means,
Cleared, and detection below the reference rated current value is performed at the specified time.
The feature is that the addition of the previous accumulated time is continued if the time is less than
Overload detection method for the grain dryer motor.