JPH0677689B2 - Starter for circulating rice mill - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement of a circulating rice milling machine in which a resistor is freely moved back and forth in a grain circulation path to automatically adjust a whitening power.

(Prior Art) Generally, in a circulating type rice milling machine, as the rice polishing progresses over time, the flow resistance of the grain decreases and the whitening power tends to decrease. For this reason, conventionally, there is known one in which a load current of a rice-polishing motor that rotates a rice-polishing screw is detected, and a resistor is automatically moved based on the detected value to keep a whitening power constant ( For example, JP-A-57-21942).

(Problems to be Solved by the Invention) In a rice milling machine with an automatic whitening force adjusting mechanism that automatically moves a resistor in this way, conventionally, for example, the rice milling motor is turned off during operation and once operated. When restarting after stopping, the resistor is in the forward position and is in a state of adding a large resistance to the grain, so the initial resistance when restarting the operation is added to this and the sail rice polishing motor is overloaded , The rice milling screw was sometimes unable to rotate.

Not only when the operation is restarted after such an interruption, but when the operation is started in the state where the resistor protrudes into the grain circulation path and applies a resistance (or load) to the grain, conventionally, the motor for rice polishing is overloaded. Inevitably suffering from the drawback of locking, and especially when the grain is put in the rice polishing tank with the circulation shutter on the entrance side of the rice milling screw open and the start switch is turned on, or when the milled rice has a high water content, There was a stronger tendency for the rice milling motor to become overloaded.

An object of the present invention is to eliminate the lock (unrotatable) due to the overload of the rice-polishing motor that tends to occur at the time of starting, and to smoothly start the rice-polishing machine.

(Means for Solving the Problems) In order to achieve the above object, the present invention outputs a resistor backward signal to retract the resistor for a certain period of time after the start switch is turned on, and thereafter, for rice polishing. Start the motor.

That is, the present invention relates to a circulating rice milling machine that automatically adjusts the whitening power by projecting or retracting a resistor in the grain circulation path, and as shown in FIG. 1, a closing signal of a start switch 1 for starting the rice milling machine. Based on the
Timer circuit 2 that outputs a motor start signal after the fixed time
And a resistor moving means 4 for retracting the resistor 3 based on the resistor retract signal, and a rice polishing motor M for starting rotation of the rice polishing screw 5 based on the motor start signal.

(Operation) Since the present invention has the above-described configuration, when the start switch 1 is turned on when starting the operation of the rice polishing machine, a closing signal is output and the timer circuit 2 outputs a resistor backward signal for a predetermined time T,
As a result, the resistor moving means 4 retracts the resistor 3 to reduce the resistance applied to the grain.

When the predetermined time T has elapsed, a motor start signal is output from the timer circuit 2 and the rice polishing motor M starts to rotate to start the rice polishing operation.

(Example) Next, the Example of this invention is described based on drawing.

Fig. 2 shows the whole circulation type rice milling machine.

Reference numeral 7 denotes a rice polishing tank. A rice polishing screw 5 is horizontally installed in a rice polishing chamber communicating with the bottom of the tank, and a rice polishing motor M is connected to one end thereof. Reference numeral 8 indicates a bran-removing net. Reference numeral 9 is a circulation shutter for opening and closing the inlet of the rice polishing chamber, and 3 is a resistor for the pressure chamber 11 on the outlet side thereof, which is rotatably mounted around a base shaft 12 as a fulcrum.

Then, as shown in FIG. 3, a screw rod 14 rotated by a resistor moving motor m mounted so as to be rotatable around a spindle 13.
Is screwed through a screw pin 16 provided at one end of the support bar 15 of the resistor 3, and the resistor moving motor m is normally or reversely rotated to move the screw pin 16 back and forth along the screw rod 14, thereby supporting the support bar. Along with 15, the resistor 3 is advanced into the grain flow path to the position indicated by the alternate long and short dash line in FIG. 3, or is retracted to the position indicated by the solid line (however, the resistor 3 is indicated by the broken line).

When the rice polishing screw 5 is rotated by the rice polishing motor M,
Grains in the milled rice tank 7 are forcedly circulated in the directions of the arrows in Figs. 2 and 3, and the resistor 3 adds resistance to the flow of the grains, and the amount of protrusion of the resistor 3 is changed to adjust the whitening power. To do.

Then, the support bar 15 is rotatably connected to the resistor moving rod S integrally connected to the resistor 3 via the base shaft 12 via the support bar rotating shaft 17. A limit switch LS3 for flow detection is fixed to the support bar 15, its actuator is seen through the resistor moving rod S, and a tension spring 18 and a compression spring 19 are provided between the support bar 15 and the resistor moving rod S. Intervene. Reference numeral 20 is a stopper that comes into contact with the resistor moving rod S.

A backward position detecting limit switch LS1 for detecting the backward position of the resistor 3 and a forward stop limit switch LS2 are fastened to the upper and lower sides of the mounting frame 22 of the resistor moving motor m, respectively.

In the figure, reference numeral 23 is a white rice discharge port, and 25 is an electrical equipment box in which a later-described control circuit shown in FIG. 5 is installed.

When the resistor moving motor m rotates in the forward direction, the support bar 15 moves toward the position indicated by the alternate long and short dash line in FIG. 3, and the stopper 20 fixed to the support bar 15 hits the resistor moving rod S. By pressing this, the resistor 3 acts on the rice flow in the direction of compression. When the resistance moving motor m reverses, the support bar
When 15 moves backward but the rice is stagnant in the plane and does not flow, the resistor 3 does not move backward and stays at that position, and only the support bar 15 uses the support bar rotating shaft 17 as a fulcrum. fall back. Therefore, as in the initial operation, even if the rice polishing motor M is not rotating, there is no rice flow in the pressure chamber, and the resistance of the resistor 3 is large, the resistor moving motor m moves to the limit switch LS1 with a light load. Can be reached.

In addition to the case where the rice is stagnant in the machine in this way, the rice milling screw 5 is rotated with the circulation shutter 9 closed, or the white rice discharge port 23 is opened to flow the rice in the pressure chamber 11 downward, or When the rice is not circulating properly, for example, when the rice is not circulated correctly without being put in the rice polishing tank, the resistance moving rod S is caused by the flow pressure of the rice received by the lower surface of the resistor 3.
Is stronger than the force pressing the flow detection limit switch LS3 toward the flow detection limit switch LS3, and the resistance moving rod S
Is pushed back to the position shown by the one-dot chain line Sa in FIG. 4 and moves away from the actuator of the flow detection limit switch LS3. With this, the limit switch LS3 detects whether or not the rice is circulating properly, but in this embodiment, a special member for activating the limit switch LS3 in response to the flow of rice is not specially provided. Is performed by the resistor 3, there is an advantage that it is not necessary to increase the number of parts and there are few failures.

The tension spring 18 pulls the resistor moving rod S with a weak force to stop the deflection of the resistor 3. In FIG. 4, even if the support bar rotary shaft 17 and the base shaft 12 are arranged so that their centers are the same, the operation is the same as that described above.

Next, the circuit diagram of FIG. 5 will be described.

30 is an AC power supply, 31 is an overload protection relay, 32 is a fuse,
33 is a transformer, 34 and 35 are diode bridges, 36 is a constant voltage circuit, 37 is a power switch, and 38 is a current transformer for detecting load current.

39 and 40 are two-stage contacts of the start timer TM. When the start timer TM is set, the break contact 39 is turned on, the meter contact 40 is turned off, the contact 40 is turned on after a certain time T1 has elapsed after the setting, and then the contact is kept constant. Contact point 39 when time T2 elapses
Turns off.

Reference numerals 41 to 46 denote comparators to which two reference voltages and signal voltages are input. 48, 49, 50 are switches, resistors 51, 52, 53
To change the reference voltage of the comparators 43 and 44.

A differentiating circuit with a capacitor 56 and a resistor 57, a resistor 58 and a resistor 59.
And to form a voltage divider circuit, and resistors 57 and 61 to form a voltage divider circuit.
62 and the diode 63 form a discharging circuit of the capacitor 56, and the diode 64 and the diode 65 form a self-holding circuit of the comparator 41.

Reference numerals 66 and 67 are light emitting diodes for monitoring, which indicate whether the resistor moving motor m is rotating normally or reversely.

68, 69 and 70 are switching transistors, 71 is a relay for switching the reverse contact 72 of the resistor moving motor m,
Reference numeral 73 is a relay that switches the contact 74 for forward rotation, and 75 is a relay that switches the motor opening / closing contact 29 for rice polishing.

The diode 77 is for self-holding of the comparator 42, and silicon diodes are used for the diodes 64, 65 and 77 and the diode of the line 60.

In the figure, LS4 is a limit switch for detecting the opening / closing of the circulating shutter 9, which detects the opening / closing of the circulating shutter 9.

Then, first close the power switch 37, then start timer TM
Set the knob. When the timer TM is set, the contact 39 is turned on and the contact 40 is turned off as described above, so that power is supplied to the line 80 and each comparator is activated.

At this time, when the resistor 3 is neither at the limit position where the resistor 3 can move forward nor at the limit position where the resistor 3 can move backward, that is, when the resistor 3 can move back and forth, the mounting frame 22 of the resistor moving motor m is set to the limit switch LS1 or LS2. Without contact, all of these limit switches are closed.

And there is rice in the tank and the limit switch for flow detection
When LS3 is pushed by the resistor moving rod S and opened, as shown in the time chart of FIG. 6, the resistor 58 and the resistor 59 of the comparator 41 are connected.
Capacitor 56 and resistance 57 than the reference voltage B divided by
Within a time T that is a large amount of the input voltage A from the differentiating circuit, the output of the comparator 41 becomes H (high level), the output of the comparator 43 becomes L (low level), the transistor 68 becomes conductive, and the relay 71 operates. Then, the contact 72 for reverse rotation is closed, and the resistor moving motor m is reversely rotated. As a result, the resistor 3 retracts, the mounting frame 22 touches the retracted position detecting limit switch LS1 to turn it off, and the resistor moving motor m is de-energized, so that the resistor 3 stops. At this time, if the resistance value of the resistor 57 is changed and the time constant of the differentiating circuit of the capacitor 56 and the resistor 57 is changed, the reverse rotation time of the resistor moving motor m can be arbitrarily set.

Next, after the time T has elapsed, the input voltage A is changed to the reference voltage B.
When it becomes smaller, the output of the comparator 41 becomes L level, and the relay 75 operates by the action of the comparator 42 described later to start the rice polishing motor M, and the motor load detection signal of the current transformer 38 for load detection causes the line 81 to pass through the line 81. Then, it is input to the comparators 43 and 44. Then, these comparators 43, 44 compare with the reference voltage, and as a result, the switching transistors 68, 69 actuate the relays 71, 73 to connect and disconnect the contacts 72, 74 to rotate the resistor moving motor m forward or By reversing, the resistor 3 is projected or retracted by this, and the whitening power is automatically adjusted.

The comparator 43 is for controlling the resistance moving motor m in the reverse direction to reduce the flow load of the grain, and the comparator 44 is for rotating the resistance moving motor m in the forward direction to increase the load. It is for controlling to. Here, the reference voltage P for comparison in the comparator 43 is set higher than that in the comparator 44, and when the value v of the line 81 is higher than this reference voltage P, the resistor moving motor m is reversed and the comparator When the value v of the line 81 is lower than the reference voltage Q at 44, the resistor moving motor m is normally rotated to move the resistor 3 backward or forward.

There is a dead zone between the reference voltages P and Q of the comparators 43 and 44, and the line
When the value t of 81 is within the range, the drive signal to the resistor moving motor m is not output. This dead zone is the control target load zone to be added to the grain. Further, the resistance value is switched by the switches 48, 49 and 50, and the reference voltage is appropriately changed to set the target load range to a value according to the moisture content and grain quality of the grain. If the reference voltages P and Q are set to the same value to eliminate the dead zone width, the target load condition can be sharply controlled.

If time T1 elapses after setting the startup timer TM, contact 39
Remains on, but contact 40 switches on and the comparator
The signal level on the inverting input side of 45 becomes H and its output line
The level of 60 becomes L (0.3V). Therefore, the non-inverting input A of the comparator 41 is 1.5V, which is higher than the reference voltage B of 0.9V. Therefore, the level at the point C on the output side of the comparator 41 becomes H, and the diode a
Through, the inverting input of the comparator 43 also becomes H level. As a result, the base of the pnp switching transistor 68 becomes L level, and since the input on the non-inverting side of the comparator 44 is H level, its output also becomes H level, only the transistor 68 is turned on, and the relay 71 works and the contact 72 Is turned on and the resistor moving motor m is reversely rotated, whereby the resistor 3 is retracted to the minimum load state.

Here, if the resistors 82 and 83 of the voltage dividing circuit of the inverting side input of the comparator 42 are respectively set to 50 kΩ, the resistor 75 of the voltage dividing circuit of the reference voltage side is set to 40 kΩ, and the resistor 76 is set to 10 kΩ, When the output of the comparator 41 is H level (5.0V), point E becomes 2.5V due to the voltage dividing circuit.

Then, when the above-mentioned time T at the time of start-up has elapsed and the input voltage on the inverting side of the comparator 42 becomes L level and its output becomes H level, the npn switch transistor 70 is turned on and the relay 75
The contact 29 turns on and the rice polishing motor M starts to rotate. At this time, the self-holding silicon diode 77 causes
The forward voltage of 0.6 V is applied to the output voltage H level of the comparator 42 (5.
4.4V subtracted from (0V) is held as the reference voltage of the comparator 42. Therefore, even if time T1 has elapsed from the timer TM setting and point C becomes H level, point E is divided and the voltage is 2.5V, so the output of comparator 42 is still at H level, and rice polishing motor M is It continues to rotate after T1 and circulates rice.

In this way, after the start timer TM is set, when the time T1 elapses, the grain circulates with the resistor 3 in the retracted state under the minimum load state, so the rotation of the rice polishing screw quickly removes bran on the grain surface. It is done and well polished (bran cycle).

The limit switch LS3 for flow detection without rice circulating
When is closed, the line 81 goes to the H level and this is input to the inverting side of the comparator 43 so that its output goes to the L level and the transistor 68 turns on, the relay 71 works and the contact 72 turns on and the resistance The body moving motor m rotates in the reverse direction.

When the screw pin 16 retracts due to the reverse rotation of the resistor moving motor m, the support bar 15 also retracts. However, when there is no rice flow, the support bar 15 is replaced by the support bar rotating shaft as shown in FIG.
It retreats around 17. This is because the resistor 3 is in the rice that does not flow and a high load is applied to the movement.

Then, when the time T2 elapses from the time T1 after the start timer TM is set and the break contact 39 of the start timer TM is turned off, the relay
75 is demagnetized, the contact 29 is turned off, and the rice polishing motor M is stopped.

Limit switch LS4 for detecting opening / closing of the circulation shutter 9
Is turned on when the circulation shutter 9 is closed, the line 85 is at H level, and the reference voltage of the comparator 46 is at H level. Therefore, the line 81 also becomes H level, and the comparator 43 operates to forcibly retract the resistor 3. Therefore, again the circulation shutter 9
When opening the rice, the rice polishing motor M is not overloaded and the operation is continued without any trouble. When the circulation shutter 9 is opened, the limit switch LS4 is off, the line 85 is at the L level, and the line 81
Also becomes L level, the resistor 3 is automatically controlled as usual.

When the circulation shutter 9 is closed, the limit switch LS4 is actuated to neither move the resistor 3 forward nor backward, but to fix the resistor 3 in the same position, it is possible to avoid overload when the shutter 9 is restarted.

A solenoid may be used to move the resistor 3 as well as a motor, and a contactless one such as a photoelectric conversion element or a reed switch may be used to detect the position of the resistor 3 without being limited to a limit switch. Good.

(Effect of the invention) In short, according to the present invention, after the starter switch 1 is closed, the resistor 3 is always retracted for a certain period of time before the rice polishing motor M is rotated. Is small and can start to rotate smoothly even with a small rice-polishing motor. Even if the motor is restarted with the resistor 3 largely protruding after the operation is interrupted due to a power failure or an erroneous operation, the rice-polishing motor M can be smoothly operated. There is an effect that it can be started and can be easily operated even by an operator unfamiliar with the handling of the rice polishing machine.

[Brief description of drawings]

FIG. 1 is a functional block diagram of the present invention, FIG. 2 is an overall side view showing an essential part of a rice polishing machine according to the present invention in cross section, and FIGS. 3 and 4 are enlarged sectional views of the essential part according to an embodiment of the present invention. , Fifth
6 is a circuit diagram thereof, FIG. 6 is a time chart showing input / output relations in the comparator 41, and FIG. 7 is a flowchart thereof. 1 is a starting switch, 2 is a timer circuit, 3 is a resistor, 4 is a resistor moving means, and 5 is a rice polishing screw.

Claims (1)

[Claims] 1. A circulating type rice milling machine in which a resistor is projected or retracted in a grain circulation path to automatically adjust the whitening power, and a resistor retracting signal is generated based on a closing signal of a start switch (1) for starting the rice milling machine. Is output for a certain period of time and a motor start signal is output after the certain period of time, a resistor moving means (4) for retracting the resistor (3) based on the resistor retract signal, and the motor start A starting device comprising: a rice polishing motor (M) for starting rotation of the rice polishing screw (5) based on a signal.