JPH0819745A - Rice pearling machine - Google Patents

Abstract

PURPOSE:To pearl the rice in a desired state without deteriorating the quality of polished rice. CONSTITUTION:This rice pearling machine is equipped with a resistor device 6 which adjusts the pearling capacity of unpolished rice, a rice pearling motor M which drives the grain feed roll 15 of the rice pearling machine 1, a frequency converter 25 installed on the input side of said motor, and a control means which controls the frequency converter 25 to adjust the number of rotation of the motor M so that it matches a set pearling capacity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rice polishing machine and a rice polishing method capable of performing desired rice polishing without deteriorating the quality of white rice.

[0002]

2. Description of the Related Art A conventional circulating rice milling machine is provided with a grain feeding roll chamber communicating with a hopper, a rice feeding roll driven by a rice milling motor, and a resistor disposed in a circulation path. Has been.

In this rice polishing machine, the grains in the hopper are forcedly circulated by the rice-sending rolls, and at the time of this forced circulation, the grains are whitened by friction between the rice-sending rolls and the grains.

The resistor acts as a circulatory load on the grain, and the polishing power changes depending on the amount of protrusion.

[0005]

The conventional rice milling machine has the following problems. (1) After polishing the rice to the desired whiteness, the amount of protrusion of the resistor is set to zero to finish the polishing to remove the bran adhering to the polished rice. I won't.

(2) The protruding amount of the resistor is determined according to the quality of the grain, but the whitening power may decrease or the grain may break during operation.

In view of the above circumstances, it is an object of the present invention to make it possible to refine rice in a desired state without impairing the quality of white rice.

[0008]

SUMMARY OF THE INVENTION The present invention provides a resistance device for adjusting the whitening power of a grain; a motor for driving a main shaft of a rice polishing machine; The frequency conversion device for adjusting the number of rotations of the motor M is provided in order to achieve the above object.

[0009]

When the power of the rice mill is turned on, the main shaft of the circulating rice mill rotates while the frequency is controlled by the frequency converter. Then, the grain transfer roll rotates, and the brown rice in the hopper is forcibly circulated to be pearled (pollinating process).
When the polishing process is completed and the finishing process is completed, the frequency conversion device changes the frequency to rotate the motor at high speed. Therefore, the polishing effect of the centrifugal force is increased, and the bran becomes clean white rice.

[0010]

Embodiments of the present invention will be described with reference to the accompanying drawings. The hopper 2 of the circulation type rice milling machine 1 communicates with the entrance side of the grain transfer roll chamber 4 via a shutter 3. The outlet 4a side of the grain transfer roll chamber 4 communicates with the hopper 2 via a circulation path 5.

A resistance rod 7 of a resistance device 6 projects into the circulation path 5. As shown in FIG. 2, the resistance device 6 includes a resistance rod 7 with a stopper 13 screwed to a coupling 10, a position adjusting motor m for rotating the coupling 10, and a normal or reverse rotation of the motor m. The control means 12 is provided. As the motor m, either an AC motor or a DC motor may be used.

The stopper 13 regulates the sliding range of the resistance rod 7. Therefore, even if the control means 12 fails and the motor m rotates too much, the resistance rod 7 does not come out too much, so that the whitening power does not become excessive.

In the grain transfer roll chamber 4, a grain transfer roll 15 which is the main axis of the rice polishing machine is disposed, and a pulley 17 of the grain transfer roll 15 is a pulley 19 of an AC rice polishing motor M via a belt 18. Are linked to. A frequency converter 25 is provided on the input side of the rice polishing motor M.

The frequency converter 25, as shown in FIG.
The converter unit 26, the inverter unit 27, and the control circuit 2
8, an oscillator 30, and a frequency changeover switch 31. The converter unit 26 converts a single-phase AC power supply into a DC power supply, and the inverter unit 27 is a converter unit 2.
The DC power supply from 6 is converted into a three-phase AC power supply. The control circuit 28 controls the output voltage from the inverter unit 27, and the oscillator 30 oscillates the frequency required for the inverter unit 27 to output. The switch 31
Is connected to the oscillator 30 and switches the output frequency from the inverter unit 27.

If a voltage doubler rectifier circuit is used as the converter unit 26, for example, a commercial 100V AC power source has 282V.
It becomes the DC power supply of, and when it is converted to AC, it becomes 200V.

A control means 35 is connected to the frequency converter 25. As the control means 35, for example, a timer switch is used, and the frequency changeover switch 31 is changed over after a lapse of a predetermined time.

The frequency conversion device 25 controls the rotation speed of the motor by changing the frequency. In this device 25, a wide range of speed control from low speed to high speed can be continuously and efficiently performed. . By using the frequency conversion device 25, 50 cycles and 60 cycles can be converted into each other, and of course, single-phase alternating current and three-phase alternating current can be converted into each other.

A first embodiment of the present invention will be described with reference to FIGS. When the position adjusting motor m is driven by the control means 12 such as a timer, the coupling 10 rotates and the resistance rod 7 of the resistance device 6 slides in the axial direction. This resistance rod 7
The amount of protrusion L of the rice into the circulation path 5 is adjusted so as to match the moisture content, shape, softness, etc. of grain, such as brown rice G, and the whitening power. After adjusting the two-contact type timer switch 35 to set the polishing step to 30 minutes and the finishing step to 15 minutes, the power source DG of the rice polishing machine 1 is turned on. Then, the alternating current from the power source DG is converted into an alternating current of a predetermined frequency through the frequency conversion device 25 and output to the alternating current rice polishing motor M.

When the rice polishing motor M rotates, the grain transfer roll 15 rotates via the belt 18. Brown rice G in hopper 2
Fall into the grain transfer roll chamber 4 and the grain transfer roll 1
5 is forcibly sent to the circulation path 5 and rises in the circulation path 5 while receiving the resistance of the resistance rods 7 of the resistance device 6 and the hopper 2
Return to inside. By repeating such a process, the polishing process within 30 minutes is completed.

During the polishing process, as shown in FIG. 6, the first contact P1 of the timer switch 35 is ON, the second contact P2 is OFF, and the single phase supplied to the converter unit 26 of the frequency converter 25 is supplied. The AC power supply is the inverter unit 27
Is converted to a three-phase AC power source at a frequency of 6
It is converted to 0HZ and output to the motor M. The rotation speed of the motor M at this time is, for example, 800 R · P · M.
Further, the required power KW of the motor M gradually increases as shown in FIG. 5, but its maximum value is 0.6 KW.

When the polishing process is completed, the finishing process is started, and the first contact P1 of the timer switch 35 is turned on and the second contact P2 is turned on.
Is turned on, and the converter unit 2 in the frequency conversion device 25 is turned on.
The single-phase AC power supply supplied to 6 is converted into a three-phase AC power supply having a frequency of 90HZ by the inverter unit 27 and output to the motor M. The rotation speed of the rice-polishing motor M at this time is, for example, high-speed rotation of 1200 R / P / M. This high-speed rotation enhances the effect of polishing rice due to centrifugal force and enables efficient removal of bran in a short time. In the finishing process, the required power KW gradually decreases as shown by the curve in FIG.

Incidentally, the number of rotations of the rice-polishing motor is set to 800 R / P / M in the polishing process and 120 in the finishing process.
Average rice bran adhesion rate (%) when 0R / P / M (B)
And (A) when 800 R · P · M was maintained without changing the rotation speed, the results were as shown in FIG. 7. As is clear from this figure, it is clear that the white rice produced by the high-speed operation using the frequency converter is significantly more beautiful.

In a circulation type rice milling machine equipped with a debranching fan driven by a rice milling motor, the debranching fan also rotates at a high speed in the finishing process, so that the wind debranching is also improved and the circulation type rice milling machine is improved. It is possible to remove the attached rice bran, which was the biggest drawback, and obtain beautiful white rice.

A second embodiment of the present invention will be described with reference to FIGS. 8 and 9. The difference between this embodiment and the first embodiment is that the frequency conversion device 25 is provided in the single pass type rice milling machine. ,
Further, the whitening force sensor S for detecting the whitening pressure of the grain is provided. The whitening force sensor S may be any sensor that can detect whitening pressure, and for example, a strain sensor or a pressure sensor provided in the whitening chamber 15a, a current sensor that detects a current value of a rice polishing motor, or the like is used.

When the resistance device 47 is manually set to a predetermined value, the rice polishing time is set by the time switch T, and the power source DG of the rice polishing machine is turned on, the alternating current from the power source DG passes through the frequency conversion device 25. The AC current having a predetermined frequency is output to the rice polishing motor M.

When the rice polishing motor M is driven, the hopper 2
The brown rice G in the inside is sent into the whitening chamber 15a by the grain transfer roll 15, and after being whitened by the whitening roll 53 which forms the main axis while receiving the resistance of the resistance device 47 in the whitening chamber 15a, from the outlet of the whitening chamber 15a. It is discharged to the white rice drop gutter 51. When the predetermined time has passed, the time switch T is turned off and the motor M
Stops.

The whitening pressure during whitening is detected by the whitening force sensor S, and the output thereof is converted into a voltage by the conversion circuit 44. Then, this converted voltage is compared with the reference voltage by the comparison circuit 45. This reference voltage is the adjustment dial B
Will be adjusted. When a difference occurs between the two voltages, the comparison circuit 45 outputs and controls the frequency conversion device 25. Therefore, the frequency is converted, the rotation speed of the rice polishing motor M is controlled, and, for example, 800R. P. It becomes M, and it becomes the set whitening power. In FIG. 8 and FIG. 9, 46 is a forward and return circuit, 49 is a bran suction fan, and 50 is a lever of the shutter 48. In this embodiment, the set value of the resistance device was not changed during rice polishing, but it is needless to say that it may be changed during rice polishing as needed.

A third embodiment of the present invention will be described with reference to FIGS. 10 and 11. The difference between this embodiment and the second embodiment is that the frequency conversion device 25 is provided in the hulled rice polishing machine, and ,
The output of the comparison circuit 45 controls the resistance device 67 and the rice polishing motor M.

The control means 12 drives the motor m to set the resistance device 67 to a predetermined value and the time switch T to the set rice polishing time. AC power supply D for rice mill
When G is turned on, the alternating current from the power source is converted into an alternating current having a predetermined frequency by the frequency conversion device 25 and output to the motor M.

When the rice polishing motor M is driven, the removing fan 60 and the grain transfer roll 15 rotate, and the paddy K in the paddy hopper 61 is rotated.
After being separated into brown rice G and rice grain H by the removing fan 60, it is flipped up and supplied to the wind-selecting device 62, and separated into brown rice G and rice grain H.

The separated rice grain H is sent to the cyclone J via the rice husk suction fan 63, while the brown rice G falls into the brown rice hopper 2 and then is fed into the whitening chamber 15a by the grain feeding roll 15 as the main axis. After being whitened by the whitening roll 53 while receiving the resistance of the resistance device 67 in the whitening chamber 15a, it is discharged from the outlet of the whitening chamber 15a to the white rice drop gutter 51.

The polishing pressure during polishing is detected by the rice polishing sensor S, and the output thereof is converted into a voltage by the conversion circuit 44. Then, this converted voltage is compared with the reference voltage by the comparison circuit 45. This reference voltage is adjusted by the adjustment dial B. When a difference occurs between both voltages, the comparison circuit 4
5 controls the frequency converter 25 and the control means 12 of the motor M.

Therefore, the frequency is converted, the rotation speed of the rice-polishing motor M is controlled, and the set whitening power is obtained. At this time, since the resistance force of the resistance device 67 is also controlled at the same time,
Since no unreasonable load is applied to the brown rice in the polishing room, no broken rice is generated. When the set time has elapsed, the timer switch T is turned off and the motor M is stopped.

Generally, this type of rice milling machine uses a removing fan and a wind separator, but if the removing fan rotates too fast, crushed rice occurs, and conversely, if it is too low, removing The rate gets worse. Also, if the rotation of the suction fan that sucks the grain is too high, the suction pressure of the air-selection device will be high, and the brown rice will be discharged together with the grain. Conversely, if it is too low, the grain will be mixed into the brown rice. Will end up. Both devices having such a problem can be easily solved by converting the rotation speed of the motor M using the frequency conversion device 25.

By using the frequency converter 25, the value of the rice polishing machine can be further enhanced as described below. (1) Motor output is insufficient due to voltage drop in mountainous areas,
Even if the motor cannot be operated, it can be operated by rotating the motor at a low speed by the frequency conversion device.

(2) The rotation speed of the centrifugal force removing fan can be adjusted in three steps or steplessly by the frequency converter. By this adjustment, the optimum number of rotations suitable for the quality of the paddy, the water content, etc. can be obtained, and the best state can be obtained in terms of the removal rate, crushed rice, efficiency, etc.

(3) Since 50HZ and 60HZ can be converted to each other by the frequency conversion device, it is not necessary to carry out production by power supply frequency when manufacturing a rice polishing machine.

(4) The frequency converter can convert single-phase alternating current and three-phase alternating current into each other. Therefore, it is possible to drive a three-phase AC motor, which has a simple structure and is inexpensive, by using the wiring of the single-phase AC motor.

The embodiment of the present invention is not limited to the above, and for example, the circulating rice mill may be controlled as shown in FIG. 8 or FIG. The single-pass type rice milling machine may be controlled as shown in FIG. 10, and the hulled rice milling machine may be controlled as shown in FIG.

[0040]

Since the present invention is configured as described above, it is possible to adjust the rotation speed of the rice-polishing motor so that the quality and the degree of whitening are set. Therefore, desired clean white rice can be obtained without generating broken rice.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a circulation type rice milling machine showing a first embodiment of the present invention.

FIG. 2 is an enlarged view of the resistance device of FIG.

FIG. 3 is a block diagram of the frequency conversion device of FIG.

FIG. 4 is a diagram showing the relationship between the number of rotations (R / P / M) of a rice-polishing motor and the rice-polishing time (minutes).

FIG. 5 is a diagram showing the relationship between the number of rotations (R · P · M) of a rice-polishing motor and the required power (KW).

FIG. 6 is a view showing that the first contact and the second contact of the timer switch are ON,
It is a figure which shows the relationship between OFF and time (minute).

FIG. 7 is a graph showing the relationship between the rotation speed and the average bran adhesion rate,
Is 800R • P • M, and B is 1200R • P • M.

FIG. 8 is a block diagram showing a second embodiment of the present invention.

FIG. 9 is a vertical sectional view of a single-pass rice milling machine showing a second embodiment of the present invention.

FIG. 10 is a block diagram showing a third embodiment of the present invention.

FIG. 11 is a longitudinal sectional view of a hulled rice polishing machine showing a third embodiment of the present invention.

[Explanation of symbols]

 6 Resistor 15 Grain Roll 20 Motor for Rice Polishing 25 Frequency Converter

Claims (12)

[Claims] 1. A resistance device for adjusting the grain whitening power; a motor for driving a main shaft of a rice polishing machine; a rotation speed of the motor provided on the input side of the motor so as to match the set whitening force. A rice milling machine comprising: a frequency converter for adjusting; 2. The rice milling machine according to claim 1, wherein the rice milling machine is a single-pass type rice milling machine. 3. The rice polishing machine according to claim 1, wherein the rice polishing machine is a hulled rice polishing machine. 4. A resistance device of a circulation type rice milling machine for adjusting grain polishing power; an AC motor for driving a main shaft of the circulation type rice polishing machine; provided on an input side of the motor and adapted to a set polishing power. And a frequency conversion device that adjusts the rotation speed of the motor so that the rice milling machine. 5. The rice polishing machine according to claim 4, wherein the frequency conversion device controls the number of rotations of the motor at the time of finishing whitening at a higher speed than that at the time of polishing. 6. A frequency conversion device is required for a converter section, an inverter section for converting an output from the converter section into an alternating current, a control circuit for controlling the inverter section, and an output from the inverter section. 6. A rice milling machine according to claim 1 or 5, further comprising: an oscillator that oscillates various frequencies. 7. The rice milling machine according to claim 6, wherein the converter section includes a voltage doubler rectifier circuit. 8. The frequency conversion device converts a single-phase AC power supply and a three-phase AC power supply to each other.
Alternatively, the rice polishing machine described in 4. 9. The frequency conversion device converts 50 cycles and 60 cycles to each other.
Alternatively, the rice polishing machine described in 4. 10. A rice polishing method in which a resistance device of a rice polishing machine is fixed to a predetermined value and a motor of the rice polishing machine is driven to rotate a main shaft to perform rice polishing; and a whitening force detection step of detecting a current value of the motor. A comparison step of comparing a current value detected by the whitening force detection step with a reference value; a frequency conversion device is controlled by the output of the comparison step, and the rotation speed of the motor is adjusted so as to match the set whitening force. A method for milling rice, which comprises a step of adjusting. 11. A method for milling rice in a circulating type rice milling machine in which a set value of a resistance device of the circulating type rice milling machine is adjusted, and a main shaft is rotated while a rotation frequency of a motor of the rice milling machine is adjusted by a frequency converter. The rice polishing method is characterized in that the number of revolutions of the motor at the time of finishing and polishing is controlled at a higher speed than that at the time of polishing by the frequency conversion device. 12. A rice polishing method comprising controlling a resistance device of a rice polishing machine to adjust whitening power and rotating a main shaft while adjusting a rotation speed of a motor of the rice polishing machine by a frequency conversion device to perform rice polishing; A whitening force detection step for detecting a current value of the motor; a comparison step for comparing a current value detected by the whitening force detection step with a reference value; and the resistance device and the frequency conversion device based on the output of the comparison step. And a step of adjusting the value of the resistance device and the rotation speed of the motor so as to match the set polishing power.