JP3779185B2 - Rice milling machine whiteness detection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a milling degree detection device for a rice mill.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a circulation type rice mill, the degree of milling of rice grains in the milled rice is detected and the rice mill is controlled according to the detection result. As a conventional method for detecting the degree of milling, it is known to detect the degree of milling together with the yield of the milled rice from the amount of reduction in the weight of the rice grains put into the rice mill (see Japanese Patent No. 2626924). It is also known to detect the degree of milling based on the reduction rate of the load current of the rice milling motor (see Japanese Patent Publication No. 7-32883). In addition, in a rotary rice mill, it is also known that the degree of milling is estimated from the lapse of the milling time according to the weight of the rice grain.
[0003]
[Problems to be solved by the invention]
However, the method for detecting the degree of milling from the amount of reduced weight of the rice grains put into the hopper has a disadvantage that a measuring means is required, and causes a high cost. Moreover, since the weight of rice grains changes according to the amount of water contained, there is a problem that the reduction in the weight of rice grains and the degree of milling do not exactly match. In addition, the method of detecting the degree of milling based on the change in the load current of the rice milling motor is based on the magnitude of the load current affected by the weight change when the weight of the rice grain changes according to the amount of moisture contained as described above. Fluctuates. Therefore, there is a problem that the change in the load current and the degree of whitening do not exactly match even in this method.
[0004]
Thus, conventionally, the rice milling degree was indirectly detected by replacing the weight of rice grains during rice milling with changes in the weight of rice grains, fluctuations in load current, lengths of time, etc., so there was a lot of room for error. It was.
[0005]
Then, this invention makes it a subject to detect the whiteness degree correctly and easily by directly detecting the whiteness of the outer surface of the rice grain in polished rice.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present invention is the outlet of rice hopper communicates with the rice chamber, through the return passage from the outlet of the rice chamber constitutes a circulation path to return to the rice hopper, said rice hoppers In the milling degree detection device of the circulation type rice mill that circulates the rice grains thrown into the circulation passage in the circulation passage, an optical whiteness sensor is provided in the middle of the circulation passage. According to this configuration, since the degree of whitening can be determined by comparing the reflectance of the detection light reflected from the rice grain and the reference value, the degree of whitening can be accurately detected without being affected by the moisture content of the rice grain. Can do.
[0007]
The milling degree sensor may be installed in the middle of the circulation passage, it is desirable to mount the discharge port or the return path of the hopper flows rice concentrates. When attaching to the discharge port, it is desirable to form a cylindrical shape in which the center line of the discharge port is the vertical direction in order to make the flow of rice grains uniform.
[0008]
Further, it is possible to employ a configuration in which the whiteness degree sensor faces the circulation passage (discharge port or return passage) through a transparent detection window. With this configuration, the sensor does not touch rice grains directly.
[0009]
In addition, it is possible to adopt a configuration in which the reference value for comparison when determining the degree of whitening from the output value of the whitening degree sensor is determined by the magnitude of the voltage based on the reflection from the brown rice put into the hopper. Further, it is possible to take a circuit configuration in which the output of the whiteness sensor is sampled for a predetermined time and the average value of the sampling values is compared with the reference value to determine the whiteness.
[0010]
As the light emitting element of the whiteness sensor, one having a wavelength of 400 to 600 nm as the wavelength of detection light emitted therefrom can be used, for example, a blue LED or a green LED can be used.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings. Rice mill according to the first embodiment shown in FIG. 1, on the seminal US motor Ta 2 installed on the machine base 1, through the bran receiving chamber 3, rice chamber 4 is provided. A milled rice roll 5 that is horizontally cantilevered is inserted into the milled rice chamber 4. The milled rice roll 5 is driven by a milled rice motor 2 through a belt 6.
[0012]
An entrance passage 7 communicates with the entrance of the rice mill 4 and the entrance passage 7 is connected to the discharge port 9 of the hopper 8. A shutter 11 is provided at a boundary portion between the discharge port 9 and the inlet passage 7 so as to be slidable by engagement between a rack 12 (see FIG. 1B) and a pinion 13 provided on the shutter 11. The pinion 13 is driven by a shutter motor 14.
[0013]
Further, a return passage 15 is communicated with the exit of the rice milling chamber 4, and the return passage 15 is connected to the return port 16 of the hopper 8. A resistance member 17 is provided in the middle of the return passage 15 so as to protrude and retract. Further, a rice mill discharge shutter 18 facing the bottom of the return passage 15, that is, the exit of the rice milling chamber 4 is provided. As described above, the hopper 8, its discharge port 9, the inlet passage 7, the rice milling chamber 4, the return passage 15, and the return port 16 constitute a rice grain circulation passage.
[0014]
As shown in FIG. 1 (b), a detection window 19 is provided by fitting a transparent resin plate on a part of the wall surface of the discharge port 9, and the detection window 19 is covered with an opaque case 21 on the outer surface. The reflective optical sensor 22 is attached by adhesion or the like. The optical sensor 22 constitutes a whiteness sensor referred to in the present invention. As shown in FIG. 2, a light projecting unit 22a (light emitting diode) that emits detection light and a light receiving unit 22b (photodiode) for the reflected light. The light projecting unit 22a is connected to the CPU 25 via the sampling circuit 24 of the control unit 23. The light receiving unit 22 b is connected to the CPU 25 via the average value calculation circuit 26. A circuit connected to the CPU 25 via the average value calculation circuit 26, the comparison circuit 27, and the whiteness determination circuit 28 is also formed. The comparison circuit 27 is connected to the CPU 25 via the reference value memory 29. Further, the rice milling motor 2 and the shutter motor 14 are connected via an appropriate interface (not shown).
[0015]
The control unit 23 outputs a sampling pulse for a predetermined time from the sampling circuit 24 when the brown rice is put into the hopper 8 according to the rice milling program of the rice milling machine, and generates a pulsed detection light corresponding to the cycle. The light is projected onto the rice grain from the light projecting unit 22a. The light receiving unit 22b receives the reflected light, converts it into an electric signal, and inputs it to the average value calculation circuit 26 to calculate the average value of the reflectance. The calculation result is stored as a reference value in the reference value memory 29 through the CPU 25 in a voltage or other form.
[0016]
When the milling progresses and the whitening degree is detected, sampling is performed for a certain time in the same manner as described above, and the average value of the reflectance is input to the comparison circuit 27 and compared with the reference value in the reference value memory 29. Since the reference value is the reflectance of the brown rice state, it is at a relatively low level. However, as the milling progresses, the surface of the rice grain becomes white and the reflectance level increases. The level difference is input to the milling degree determination circuit 28, and the milling degree determination such as “3 minutes”, “5 minutes”, “7 minutes”, “white rice” is performed according to a predetermined standard, and is input to the CPU 25. The CPU 25 controls the rice milling motor 2 and the shutter motor 14 based on these determination results.
[0017]
3 and 4 show a more specific example of the optical sensor 22. 3 (a) and 3 (b) show an angle between the light projecting unit 22a made of a light emitting diode and the light receiving unit 22b made of a photodiode so that their optical axes intersect on the detection window 19. And attached to the sensor case 22c. The sensor case 22 c is fixed to the outer surface of the hopper 8 with screws 20 and 20. The light projecting unit 22a and the light receiving unit 22b each have a characteristic with a directivity angle of about 30 °. In the illustrated case, the diameter S of the detection range of the detection window 19 is set to 12 mm. In the case of FIGS. 4A and 4B, convex lenses 30 and 30 are provided to face the light projecting portion 22a and the light receiving portion 22b, respectively, and are arranged so as to be focused at the detection window 19.
[0018]
The optical sensor 22 can be provided in a part of the return passage 15 as shown in FIG. Since the degree of whitening of the rice grains in the return passage 15 is substantially uniform, the average average whitening degree can be accurately estimated by detecting the whitening degree.
[0019]
Moreover, the wavelength of the detection light radiated | emitted from the light emitting diode used as the light projection part 22a uses a thing of about 400-600 nm from the experimental result shown in FIG. Specifically, blue light emitting diodes and green light emitting diodes can emit light in this range. The experimental results in FIG. 6 are obtained by irradiating white rice, rice with 7 minutes, rice with 5 minutes, rice with 3 minutes, and brown rice, and measuring reflectance according to the wavelength of the detected light. As can be seen from the measurement results, in the wavelength range of 400 to 600 nm, the difference in reflectance from white rice to brown rice appears remarkably, so as described above, the degree of whiteness of rice grains based on brown rice can be detected. it can.
[0020]
The rice milling machine of the first embodiment is as described above. After the rice grains (brown rice) are put into the hopper 8 and the milling degree is set on the operation panel (not shown), the rice milling motor 2 is turned on. Drive to perform rice milling. The rice grains in the hopper 8 are introduced into the milled rice chamber 4 through the inlet passage 7 from the discharge port 9 where the shutter 11 is opened. In the milling chamber 4, it is pushed out to the return passage 15 side by the milling roll 5, but resistance is received by the resistor 17 protruding into the return passage 15, so that strong friction between the rice grains in the milling chamber 4 occurs. The whitening action is performed by this. The bran generated at this time is discharged into the bran receiving chamber 3.
[0021]
The rice grains that have passed through the return passage 15 return to the hopper 8 from the return port 16, and thereafter undergo a whitening action while circulating as the circulation passage. In the meantime, the optical sensor 22 discriminates and detects the degree of whitening according to a predetermined program, and stops the rice milling motor 2 by a command from the CPU 25 when the set value is reached. The polished rice grains are discharged by opening the discharge shutter 18 and driving the milled rice motor 2.
[0022]
Next, the rice mill of the second embodiment shown in FIGS. 7 to 12 is the same as that of the first embodiment in that it is a circulation type, but is connected to the rice mill motor-2 and its motor shaft. The difference is that the polished rice roll 5 is attached to the machine base 1 with an inclination angle of about 30 degrees.
[0023]
The rice mill roll 5 is provided with a feed portion 5a with a fine pitch on the side close to the motor shaft, and a repetitive feed portion 5b with a rough pitch from that portion to the tip. This rice milling roll 5 is inserted into a rice milling chamber 4 provided obliquely, but the lower end portion of the rice milling chamber 4 is opened facing the discharge port 9 of the hopper 8 on the side of the feeding unit 5a. Further, an anti-cylindrical shutter 11 is provided on the opposite side of the open portion so as to be rotatable by a shutter shaft 31 parallel to the milled rice roll 5 (see FIG. 9). The lower part of the shutter 11 communicates with a polished rice grain chamber 32. The shutter 11 is driven and opened / closed by a shutter motor 14 connected to a shutter shaft 31.
[0024]
A cylindrical rice milling screen 33 is provided in the rice milling chamber 4 so as to cover the rice milling roll 5 (see FIG. 8), and the braid that has passed through the mesh of the rice milling screen 33 falls into the bran receiving chamber 3 below. It has become. A return passage member 15 ′ is attached to the exit side of the rice milling chamber 4, whereby a return passage 15 is formed between the exit of the rice milling chamber 4 and the return port 16 of the hopper 8. The return passage member 15 ′ rises at an angle with respect to the axis of the milled rice roll 5, thereby giving the necessary resistance to the rice grains discharged from the milled rice screen 33.
[0025]
In this case, the rice grains fed into the milling chamber 4 from the hopper 8 are fed by the feed section 5a of the milled rice roll 5, while resistance is given by the reverse feed section 5b, and resistance by the return passage member 15 'is also given. In addition, the rice milling effect is caused by friction between rice grains.
[0026]
The optical sensor 22 (see FIG. 8) for detecting the degree of whiteness is provided at the discharge port 9, and the configuration of the control unit is the same as in the case of the first embodiment (see FIG. 2). Similarly, the optical sensor 22 may be provided in the return passage 15 (see the two-dot chain line in FIG. 7).
[0027]
It should be noted that means as shown in FIGS. 10 and 11 can be employed instead of the detection of the degree of whitening by the optical sensor 22 described above.
[0028]
That is, the electrodes 34 and 34 are embedded through the insulating members 35 and 35 at two opposing positions in the discharge port 9 of the hopper 8, and the resistance of the flow of rice grains that pass between the electrodes 34 and 34 in a dense state is measured. The resistance value is read by the control unit 23 (see FIG. 11) and the degree of whiteness is detected. The control unit 23 is provided with a resistance value reading circuit 36 for reading the resistance value between the electrodes 34, 34. In addition, a reading value sampling circuit 24, an average value calculation circuit 26 of the sampling values, and other circuits similar to those described above (see FIG. 2) are provided. The electrodes 34, 34 may be provided in the return passage 15.
[0029]
Even when the electrodes 34 and 34 as described above are provided, the resistance value between the electrodes 34 and 34 is read in accordance with a command from the CPU 25 when the brown rice is put into the hopper 8 according to the rice milling program, and is sampled by the sampling circuit 24. And input to the average value calculation circuit 26 to calculate the average value. The calculation result is stored as a reference value in the reference value memory 29 through the CPU 25.
[0030]
When rice milling progresses and it is necessary to detect the degree of milling, the resistance value is read in the same manner as described above, and an average value corresponding to the resistance value is input to the comparison circuit 27 and compared with the reference value in the reference value memory 29. To do. Since the reference value is based on the resistance value in the state of brown rice, the level is relatively low, but the moisture content on the surface of the rice grain decreases as the polished rice progresses, so the resistance value becomes a high level. The level difference is input to the whiteness determination circuit 28, and the whiteness is determined according to a predetermined standard and input to the CPU 25. The CPU 25 controls the rice milling motor 2 and the shutter motor 14 based on these determination results.
[0031]
FIG. 12 shows actual measurement results of the degree of whiteness and resistance of rice grains. With the resistance value of brown rice as a reference value, the level difference in the degree of whitening of “brown rice”, “with 5 minutes”, “with 7 minutes”, and “white rice” is about 100 MΩ, and this level difference is discriminated by the milling degree discriminating circuit 28. Like that.
[0032]
The discharge port 9 of the hopper 8 provided with the milling degree sensor such as the optical sensor 22 (see FIG. 8) and the electrodes 34 and 34 (see FIG. 10) has a center line perpendicular to the axis of the milling roll 5. is there. For this reason, in the installed state of the rice mill, the central axis of the discharge port 9 has an angle with respect to the vertical direction, so that the rice grains passing here move in contact with the wall surface of the discharge port 9, Some of them move without touching the wall surface. As a result, the flow velocity becomes non-uniform due to the difference in frictional resistance during movement, and the whitening degree detection function by the whiteness sensor becomes unstable.
[0033]
For this reason, as shown in FIG. 13, the shape of the discharge port 9 is such that its axis Y has a constant acute angle θ with respect to the axis X of the rice mill roll 5, and the vertical direction (vertical direction) when the rice mill is installed. It is desirable to form in the shape of a square cylinder or a cylinder. If formed in this way, rice grains that pass through the outlet 9 in the installed state fall uniformly in the vertical direction, so that the moving speed is constant. Therefore, the detection effect by the whiteness sensor is stabilized. The length L of the discharge port 9 is desirably 25 mm or more.
[0034]
Next, another embodiment shown in FIGS. 14 and 15 relates to a rotary rice mill. In the rotary rice mill, a cylindrical rice milling part 42 is provided on a rice milling machine main body 41, and a drive shaft 44 of a drive motor 43 (see FIG. 15) projects from the rice milling part 42. A central boss portion 45 of the milled rice portion 42 rises around the drive shaft 44, and the central boss portion 47 of the polished rice basket 46 is fitted to the central boss portion 45. An outwardly extending collar portion 48 is provided on the upper edge of the outer peripheral portion of the polished rice basket 46, and the collar portion 48 is engaged with the upper end of the polished rice portion 42.
[0035]
A rotary blade member 49 is attached to the upper end of the drive shaft 44 so as to rotate inside the polished rice basket 46. Further, the lid 50 is detachably fitted to the upper end opening of the milled rice part 42. The rotary blade member 49 is not in contact with the polished rice basket 46.
[0036]
The drive motor 43 is fixed to the rice mill main body 41 via an insulating member 51.
[0037]
The above-described rice milling machine is driven by putting brown rice into the rice mill 46 and covering it with a lid 50. The rice milling action is performed by the mutual friction of rice grains with the surrounding rice basket 46 as the rotary blade member 49 rotates. The degree of milling is measured by measuring the resistance value between the electrode 52 attached to the casing of the drive motor 43 and the other electrode 52 ′ interposed between the collar portion 48 of the polished rice basket 46 and the upper edge of the polished rice portion 42. By doing. That is, the electrode 52 attached to the drive motor 43 is electrically connected to the internal rice grain through the drive shaft 44 and the rotary blade member 49 attached thereto, and the other electrode 52 is connected to the rice basket 46. Is electrically connected to rice grains through.
[0038]
Therefore, since both electrodes 52 and 52 'are electrically facing each other only with rice grains, the resistance between them can be measured. The circuit configuration of the control unit 23 that controls the rice mill using the measurement result is the same as that shown in FIG.
[0039]
【The invention's effect】
As described above, according to the present invention, by providing an optical milling degree sensor in the middle of a circulation path in a circulating rice mill, the milling degree of rice grains can be directly adjusted without being affected by moisture contained in the rice grains. Since it is detected, the degree of whitening can be detected with high accuracy. By setting the wavelength of the detection light of the whiteness sensor to 400 to 600 nm, the whiteness can be detected more accurately. Further, by forming the discharge port of the hopper provided with the milling degree sensor into a cylindrical shape whose axis is directed in the vertical direction, the flow of rice grains is made uniform, and the function of detecting the milling degree by the milling degree sensor is stabilized.
[0040]
In addition, a transparent detection window is provided at the outlet of the hopper, and the above-mentioned milling degree sensor is attached to the outer surface of the detection window, so that the sensor does not directly touch the rice grains and is not easily damaged or damaged. is there. In addition, the output of the whiteness sensor is sampled for a certain period of time, the sampling values are averaged, and the average value is compared and discriminated with the reference value, so that the average whitening degree can be detected without being shifted to the local area. .
[Brief description of the drawings]
1A is a partially omitted cross-sectional view of the first embodiment; FIG. 1B is a partially enlarged cross-sectional view of the same; FIG. 2 is a block diagram of a control unit of the same; Cross-sectional view of another example (b) Front view of FIG. 4 (a) FIG. 4 (a) Cross-sectional view of another example of the optical sensor unit same as above (b) Front view of FIG. Cross-sectional view of another example of the optical sensor mounting portion same as above. [Fig. 6] Graph of the measurement result as above. [Fig. 7] Cross-sectional view of the second embodiment. FIG. 10 is a partially enlarged sectional view of a modification of the above. FIG. 11 is a block diagram of the control unit. FIG. 12 is a graph of an actual measurement result showing the relationship between the degree of whitening and the insulation resistance value. 13 is a cross-sectional view of a modified example of the discharge port portion of the same. FIG. 14 is an exploded perspective view of another embodiment. FIG. 15 is a partial cross-sectional view of the same embodiment.
DESCRIPTION OF SYMBOLS 1 Machine 2 Rice milling motor 3 Rice bran receiving chamber 4 Rice milling chamber 5 Rice milling roll 6 Belt 7 Entrance passage 8 Hopper 9 Discharge port 11 Shutter 12 Rack 13 Pinion 14 Shutter motor 15 Return passage 15 'Return passage member 16 Return port 17 Resistance member 18 Discharge shutter 19 Inspection window 20 Screw 21 Case 22 Optical sensor 22a Light projecting unit 22b Light receiving unit 22c Sensor case 23 Control unit 24 Sampling circuit 25 CPU
26 Average value calculation circuit 27 Comparison circuit 28 Milling degree determination circuit 29 Reference value memory 31 Shutter shaft 32 Rice milling chamber 33 Rice milling screen 34 Electrode 35 Insulating member 36 Resistance reading circuit 41 Rice mill main body 42 Rice milling section 43 Drive motor 44 Drive Shaft 45 Center boss 46 Rice mill 47 Central boss 48 Brim 49 Rotary blade member 50 Lid 51 Insulating member 52, 52 'Electrode

Claims (2)

The milling hopper discharge port is connected to the milling chamber, a circulation path is formed from the exit of the milling chamber to the milling hopper via a return path, and an optical milling degree sensor is provided in the middle of the circulation path. in milling degree detecting apparatus of the circulation type rice milling machine so as to rice was put into the hopper to detect the milling degree while fine rice is circulated in the circulating passage, the centerline of the outlet of the milled rice hopper vertically A milling degree detecting device for a rice mill, wherein the milling degree sensor is attached to the outlet . 2. The milling degree detecting device for a rice mill according to claim 1, wherein the light emitting element of the milling degree sensor is a blue LED, and the wavelength of the detection light emitted from the element is 400 to 600 nm .

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