JP4152766B2 - Paper feeder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet feeding device that blows air onto the surface layer of stacked sheets to separate one surface sheet from other sheets, and sucks and separates the separated surface sheet by air suction. Specifically, the present invention relates to the adjustment of air ejection pressure and suction pressure.
[0002]
[Prior art]
Air is blown to the upper or lower side of the paper layer stacked on the paper stacking table to separate one surface layer (uppermost or lowermost) sheet from other sheets, and the separated surface sheet 2. Description of the Related Art A sheet feeding device that sucks one sheet by sucking air and carries out the sheet is well known. In such a sheet feeding device, for example, a solenoid valve is provided in the air supply passage according to the sheet feeding speed and the amount of air sprayed is adjusted by controlling the opening amount of the solenoid valve (No. 8-5806) The voltage applied to the DC servo motor of the fan device is controlled by the PWM circuit in accordance with the weight of the stacked sheet bodies, the material or size of the paper, etc., and the amount of air sprayed is thereby adjusted ( JP-A-6-87451) is known.
[0003]
[Problems to be solved by the invention]
However, the adjustment of the amount of air using a solenoid valve or a DC servo motor has a problem that it is complicated in terms of mechanism and circuit, and its handling is troublesome and expensive.
[0004]
The present invention has been made in view of such a problem, and an object of the present invention is to provide a sheet feeding device that is a simple circuit and has a highly safe air amount adjustment unit that is less adversely affected by the generation of noise. To do.
[0005]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a paper stacking table, and a squirting air jetting unit that is disposed on a paper carry-out side of the paper stacking table and jets air toward an upper side surface of a paper layer on the paper stacking table. A sheet adsorbing / carrying means for adsorbing and carrying out one sheet of a surface layer that is blown by air spouted by the air blowing means; an AC blower motor that sucks and ejects the air; and the AC blower motor An on / off control means having a zero volt switch circuit for controlling the speed, a pressure setting means for setting an air ejection pressure of the squeezing air ejection means and an air suction pressure of the paper suction / conveyance means, and a setting by the pressure setting means And an on / off timing converting means for converting the generated pressure into an on / off timing of the on / off control means. The air suction pressure of wearing out means, characterized by comprising adjusting the speed control of the AC blower motor.
[0006]
The present invention according to claim 2 is the pressure according to the present invention according to claim 1, further comprising a display means for displaying the air pressure in a plurality of sections and an air pressure changeover switch for setting the air pressure corresponding to the displayed section. It is characterized by comprising setting means.
[0007]
In the present invention, the blower motor that sucks and ejects air is an AC motor, and the AC voltage applied to the motor is turned on and off at an appropriately set timing, and the speed of the motor is controlled by the voltage averaged by this on and off. In addition to the control, the on / off operation is performed when the AC voltage is zero volts, so that it is possible to reduce the generation of noise associated with the on / off control.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a sheet feeding device according to an embodiment of the present invention, FIG. 2 is a circuit diagram showing an example of a zero volt switch circuit, and FIG. 3 is a waveform diagram for explaining operations.
[0009]
In FIG. 1, 1 is a paper stacking base, 2 is an air ejection nozzle, 3 is a suction roller, 4 is an intake duct, 5 is an AC blower motor comprising a fan 5b and an AC commutator motor 5a, 6 is an air supply duct, and 7 is An unloading roller, 8 is an AC power source, 9 is an on / off control circuit including a triac 9a, a zero volt switch circuit 9b, and a photocoupler 9c, 10 is an on / off timing converter having a CPU and a storage device, and 11 is an air pressure. A setting device, 12 is a display device, 13 is an input / output interface, and P is paper.
[0010]
A front end portion 4 a of the air intake duct 4 is arranged in parallel with the paper stacking table 1 and above the end portion on the carry-out side of the paper P, and a suction long hole for sucking air is formed on a side surface facing the paper P. The suction roller 3 has a cylindrical shape, and a plurality of radial through holes 3a are formed. The suction roller 3 is fitted into the front end portion 4a of the intake duct 4 and is rotated by a motor (not shown). That is, air is sucked at a position where the suction long hole of the front end portion 4a of the intake duct 4 and the through hole 3a of the suction roller 3 coincide with each other, sucking the paper P by the suction, and changing the suction position of the paper P according to the rotation. The paper P is sent to the carry-out roller 7.
[0011]
The air ejection nozzle 2 is connected to the air supply duct 6 and is disposed on the paper P delivery side of the paper stacking table 1. The air jet nozzle 2 sprays air toward the upper side surface of the paper layer on the paper stacking table 1, and ) Is separated from other sheets. One sheet of the separated surface layer is sucked by the suction roller 3, thereby avoiding double feeding of the paper P. The AC blower motor 5 is disposed between the intake duct 4 and the air supply duct 6 and performs air suction and spraying by rotational driving of the fan 5b.
[0012]
The AC commutator motor 5a that rotationally drives the fan 5b is connected to the AC power supply 8 via the triac 9a, and repeats conduction and non-conduction of the triac 9a, that is, on / off, according to the on / off ratio. The average voltage is applied to the AC commutator motor 5a, and the AC commutator motor 5a, that is, the fan 5b continuously rotates at a speed corresponding to the average voltage. The air pressure setting device 11 has an operation switch that switches the air pressure stepwise, and outputs an air pressure setting signal at a step corresponding to the operation of the operation switch to the on / off timing conversion device 10. For example, the air pressure is increased or decreased every time the operation switch is operated, and an air pressure setting signal is output to the on / off timing converter 10 for each operation.
[0013]
In the on / off timing conversion device 10, a repetitive on / off cycle corresponding to each stage of the air pressure and a set value of the on time in the cycle are stored in the storage device in advance, and the air pressure from the air pressure setting device 11 is stored. In response to the input of the pressure setting signal, the ON drive pulse Pa is output to the photocoupler 9c of the ON / OFF control circuit 9 through the input / output interface 13 based on the set value corresponding to the air pressure setting signal. Further, an index of air pressure based on the air pressure setting signal is output to the display device 12 via the input / output interface 13. By displaying this index, it is possible to know the current air pressure level, and it is possible to easily set the air pressure, that is, adjust the air pressure. The on / off cycle and the on-time of the cycle are set so that the AC commutator motor 5a repeats driving / stopping and does not have a large rotational speed fluctuation. is there.
[0014]
The on / off control circuit 9 controls conduction / non-conduction of the triac 9a, that is, on / off control according to the pulse signal input to the photocoupler 9c. The on / off control circuit 9 has a zero volt switch circuit 9b. When the pulse Pa is input to the photocoupler 9c, the TRIAC 9a starts to conduct when the AC power source 8 is zero volt. When the power supply 8 is zero volts, the triac 9a is non-conductive.
[0015]
The zero volt switch circuit 9b is configured, for example, as shown in FIG. That is, in FIG. 2, Q1 and Q2 are NPN transistors, CR is a thyristor, D1 to D4 are diodes, and R1 to R4 are resistors. The diodes D1 to D4 constitute a double-wave rectifier circuit that rectifies the voltage of the AC power supply 8 both, and a thyristor CR is connected to the output side of the double-wave rectifier circuit. Due to the conduction of the thyristor CR, a trigger signal is input to the gate of the triac 9a, and the triac 9a is turned on. The trigger signal is not input to the gate of the triac 9a due to the non-conduction of the thyristor CR, and the triac 9a is non-conduction (off) when the AC power supply 8 is zero volts.
[0016]
The conduction timing of the thyristor CR is determined by the conduction / non-conduction of the transistors Q1 and Q2 connected in parallel to the gate circuit. When both the transistors Q1 and Q2 are non-conduction, a trigger signal is sent to the gate of the thyristor CR via the resistor R4. The thyristor CR is turned on when input. While the pulse Pa is input, the transistor Q1 is in a non-conducting state (the light emitting diode LED emits light and the photodiode PT is in a conducting state), and the transistor Q2 is in a conducting state (in this state, the triac 9a is high). Is set to be non-conductive)), the trigger signal is not input to the gate of the thyristor CR and the thyristor CR is non-conductive, but when the output voltage of the two-wave rectifier circuit is close to zero, the transistor Q2 is non-conductive. The thyristor CR is turned on, a trigger signal is input to the gate of the thyristor CR via the resistor R4, and the thyristor CR is turned on. In this state, a trigger signal is input to the gate of the triac 9a via the thyristor CR, and the triac 9a is turned on (turned on). That is, the triac 9a becomes conductive (on) when the AC power supply 8 is at zero volts. When the pulse Pa is not input, the transistor Q1 is in a conductive state (in this state, the circuit is set so that the triac 9a is not conductive), and no trigger signal is input to the gate of the thyristor CR, and the thyristor CR is Maintain non-conducting state.
[0017]
In the paper feeding device configured as described above, for example, the paper P to be fed is lightly separated from other paper by a small air jet pressure, and is sucked by the suction roller 3 by a small air suction pressure. When the air pressure is set, the operation switch of the air pressure setting device 11 is operated to set, for example, the lowest air pressure. With this setting, as shown in FIG. 3A, the on / off timing conversion apparatus 10 sets one cycle and a half of the voltage S of the AC power supply 8 as a period Ta and a width corresponding to a half cycle of the voltage S of the AC power supply 8. And a half cycle voltage is applied to the AC commutator motor 5a every other cycle of the voltage S of the AC power supply 8. By this application, AC commutator motor 5a rotates at the lowest speed and supplies a small air spray pressure and suction pressure.
[0018]
If the air spray pressure and suction pressure are insufficient in this setting, the operation switch of the air pressure setting device 11 is operated to set the air pressure to be increased by one step, for example. With this setting, as shown in FIG. 3B, the on / off timing conversion apparatus 10 sets one cycle of the voltage S of the AC power supply 8 as a period Ta, and has a width corresponding to a half cycle of the voltage S of the AC power supply 8. A pulse Pa is output, and a half-cycle voltage is applied to the AC commutator motor 5a every half cycle of the voltage S of the AC power supply 8. By this application, the AC commutator motor 5a increases the speed and supplies the increased air spray pressure and suction pressure. Thereafter, as shown in FIGS. 3 (c) and 3 (d), a voltage of one cycle is applied every half cycle of the voltage S of the AC power supply 8 according to the required air spraying pressure and suction pressure. A voltage of one cycle and a half is applied every half cycle of the voltage S. Thus, by setting the air spray pressure and suction pressure in multiple stages, it is possible to obtain the optimum spray pressure and suction pressure according to the paper feed speed, paper weight, paper material or size, etc. it can.
[0019]
The zero volt switch circuit is not limited to the circuit shown in FIG. 2, and other zero volt switch circuits may be employed. Further, in the above embodiment, paper is fed in order from the uppermost layer of paper stacked on the paper stacking table, but the present invention can also be applied to paper fed in order from the lowermost layer of paper.
[0020]
【The invention's effect】
As described in detail above, according to the present invention, the AC voltage applied to the blower motor is frequently turned on / off, but since the zero volt switch circuit is used, there is almost no noise generation, and other noises caused by this noise are generated. An adverse effect on the electronic device can be eliminated, and a highly safe paper feeding device can be obtained. In addition, the combination of the on / off timing setting and the zero volt switch circuit is simple and easy to handle, and it is possible to obtain highly accurate air injection pressure and suction pressure. Therefore, the cost of the paper feeding device can be reduced.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a sheet feeding device according to an embodiment of the present invention.
FIG. 2 is a circuit diagram showing an example of a zero volt switch circuit.
FIG. 3 is a waveform diagram for explaining the operation of the sheet feeding device according to the embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Sheet collecting stand 2 Air ejection nozzle 3 Adsorption roller 4 Intake duct 5 AC blower motor 5a AC commutator motor 5b Fan 6 Air supply duct 7 Outlet roller 8 AC power supply 9 On / off control circuit 9a Triac 9b Zero volt switch circuit 9c Photocoupler 10 ON / OFF timing conversion device 11 Air pressure setting device 12 Display device P Paper

Claims (2)

A paper stacking table; a blowing air jetting unit that is disposed on a paper carry-out side of the paper stacking table and blows air toward an upper side surface of a paper layer on the paper stacking table; and the blowing air jetting unit jets A sheet adsorbing / unloading means for sucking and discharging one sheet of the surface layer that is blown with air by sucking air; an AC blower motor for sucking and ejecting the air; and a zero volt switch circuit for controlling the speed of the AC blower motor Provided on / off control means, pressure setting means for setting the air ejection pressure of the air blowing means and the air suction pressure of the paper suction / conveyance means, and the pressure set by the pressure setting means as the on / off control means ON / OFF timing conversion means for converting to the ON / OFF timing of the air, and the air suction pressure of the air blowing means and the air suction of the paper suction / conveying means Sheet feeding apparatus, wherein a pressure obtained by adjusting the speed control of the AC blower motor. Display means for displaying by dividing the air pressure in a plurality, the sheet feeding according to claim 1, characterized in that it comprises a pressure setting means having an air pressure switching switch for setting the air pressure corresponding to segments of displaying apparatus.

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