JPH0123760Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field of the invention] This invention relates to a cutter drive device that can suppress overrun of the rotary blade after cutting without using mechanical means in a rotary cutter device driven by a DC motor. It is something.

[Prior art]

Conventionally, in most rotary cutters, mechanical means have been used to prevent and suppress overrun of the rotary blade. In another method of this kind, as shown in FIG. 1, immediately after the rotary blade 1 that cuts the paper together with the fixed blade 2 passes a predetermined braking position, a DC motor 3 that drives the rotary blade 1 is used.
A cutter drive method is known in which the two poles of the rotary blade are short-circuited, but the amount of overrun of the rotary blade 1 is large;
Furthermore, although it depends on the specifications of the DC motor 3 and the reduction ratio, the amount of overrun varies by about 30 degrees due to factors such as fluctuations in power supply voltage and changes in temperature. Therefore,
For example, when this drive system is used in a cutter device used for paper cutting such as a printer device, the rotary blade 1 may obstruct the advance of the paper due to fluctuations in the amount of overrun of the rotary blade 1, resulting in a paper jam. Therefore, it was not suitable for practical use unless mechanical assistance was used.

[Summary of the idea]

This idea was made to eliminate the drawbacks of the conventional ones as mentioned above, and it drives the rotating blade.
The DC motor is initially applied with the motor rated voltage for constant speed high torque drive, then after the deceleration position a low voltage is applied to decelerate and low torque drive, and then when the braking position is reached, this low torque is applied. To provide a cutter drive device capable of suppressing the amount of overrun of a rotary blade to a practically acceptable level by applying a voltage for braking in the cutter state without using mechanical auxiliary means for braking. The purpose is to

[Example of idea]

Hereinafter, embodiments of this invention will be described with reference to the drawings.

FIG. 2 shows an embodiment of the present invention. In the figure, 21 is a rotating blade, 22 is a fixed blade attached to the rotating blade 21, and 23 is attached to the rotating shaft of the rotating blade 21. A detection plate is provided with a slit 24, the first edge 25 corresponding to the deceleration position and the second edge 26 corresponding to the braking position. In addition, 27 is the first edge 2
5. A position detector for detecting the second edge 26. The detection plate 23 and the position detector 27 constitute a position detection means. 28 is a control circuit that controls the DC motor 29 in response to the detection output of the position detector 27; 29 is a DC motor that drives the rotary blade 21;
A decelerator 30 decelerates the rotation of the DC motor 29 and transmits the deceleration to the rotary blade 21.

FIG. 3 shows an example of the control circuit 28. 35
is a trigger input terminal, 36 is an input terminal for the detection output of the position detector 27, 37 is an output terminal for voltage applied to the cutter, 41 to 44 are transistors, 45, 46
is a resistor, 51 to 53 are inverters, 54 and 55 are flip-flops, 56 is a NAND circuit, and 57 to 53 are flip-flops.
62 is a resistor, 70 is a timer, and Vcc is a power supply voltage.

Next, the operation will be explained.

First, in the standby state, the rotary blade 21 is at a position rotated several degrees in the forward rotation direction 31 from the braking position.
Here, when a trigger pulse is applied to the trigger input terminal 35 of the control circuit 28, the outputs of the flip-flops 54 and 55 are "H", and the outputs of the inverter 53 and
The output of the NAND circuit 56 becomes "L" and the transistors 41 and 42 turn on.
The voltage at the output terminal 37 becomes approximately Vcc, the rated voltage is applied to the DC motor 29, and the rotary blade 21 starts rotating. When the rotary blade 21 reaches the deceleration position, the position detector 27 detects the first edge 25,
The position sensor output level changes from "L" to "H", and as a result, the output of the flip-flop 55 becomes "L" for a certain period of time determined by the timer 70.
Transistor 41 is OFF, transistor 42 is
OFF, the transistor 44 turns ON, the voltage at the output terminal 37 becomes 0, and both poles of the DC motor 29 are short-circuited via the protective resistor 45.
The DC motor 29 is in a braking state. After the above certain period of time has elapsed, the NAND
The output of the circuit 56 is “H” and the transistor 41 is
OFF, transistor 42 is ON, transistor 4
4 becomes OFF, and the resistor 46 is connected to the output terminal 37.
A voltage lower by the voltage drop caused by is applied to the DC motor 29. When the rotary blade 21 further rotates and the position detector 27 detects the second edge 26, the detector output level becomes "H".
becomes “L”, and transistors 41 and 42 become “L”.
OFF, transistor 44 turns ON, and DC again.
Both poles of the motor 29 are short-circuited, and the rotation of the DC motor 29 is stopped. The amount of overrun at this time is about 1/3 to 1/4 compared to the conventional method.

As described above, according to this embodiment, the rated voltage is applied to the DC motor 29 that drives the rotary blade 21 of the cutter until cutting that requires high torque, and the rated voltage is applied to the DC motor 29 that drives the rotating blade 21 of the cutter.
After sufficient cutting with ~1/5 torque, a low voltage is applied, and then both poles of the DC motor 29 are short-circuited, so that the rotary blade 21 can be cut without using any mechanical means for braking. The amount of overrun can be made extremely small.

Note that in the above embodiment, after reaching the deceleration position, zero voltage is applied for a certain period of time, and after that certain period of time, a low voltage is applied. If it is made variable accordingly, the amount of overrun can be suppressed with more precision.

Further, after reaching the braking position, both poles of the DC motor are short-circuited, that is, zero voltage is applied to the DC motor, but this may be done by short-circuiting both poles after applying a reverse voltage.

[Effect of idea]

As described above, according to this invention, the motor rated voltage, which requires high torque, is applied to the DC motor that drives the rotary blade of the cutter at first, and then a low voltage is applied to reduce the speed and drive the rotary blade at low torque. Then, in this low-torque driving state, zero voltage is applied for braking, so there is an effect that the amount of overrun of the rotary blade can be extremely reduced without using any mechanical means for braking.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a conventional rotary cutter device, FIG. 2 is a perspective view showing a cutter drive device according to an embodiment of this invention, and FIG. 3 is a circuit diagram showing a control circuit of the above embodiment. . 21... Rotating blade, 22... Fixed blade, 23... Detection plate, 27... Position detector, 28... Control circuit, 2
9...DC motor.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A rotary blade, a fixed blade installed in contact with the rotary blade, a DC motor that drives the rotary blade, and a DC motor that detects the deceleration position and braking position of the rotary blade. a position detection means for outputting each detection signal at the time of starting the drive of the rotary blade; control for applying a deceleration voltage for driving the rotary blade at low torque in response to the input, and further applying a braking voltage for stopping the rotary blade to the DC motor in the low-torque driving state when the braking position detection signal is input. A cutter drive device comprising: (2) Claim 1 of the utility model registration claim characterized in that the deceleration voltage is zero voltage for a certain period of time, and a predetermined voltage lower than the motor rated voltage until the braking position after the certain period of time. cutter drive device. (3) The cutter driving device according to claim 2, wherein the predetermined voltage of the deceleration voltage is variable depending on the power supply voltage or the temperature. (4) The cutter drive device according to claim 2 of the utility model registration claim, characterized in that the fixed time during which the deceleration voltage is reduced to zero voltage is variable depending on the power supply voltage or the temperature. (5) The cutter drive device according to claim 1, wherein the braking voltage is zero voltage. (6) The cutter drive device according to claim 1, wherein the braking voltage is a reverse voltage for a certain period of time and then becomes zero voltage.