JPS5854593B2 - Abnormal rotational speed detection circuit in on/off control - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotation speed abnormality detection circuit for on/off control in a paper card punch printing device.

When punching and printing on paper cards are performed using the same device, the entire feeding path is constructed as shown in FIG.

The operation of the apparatus shown in FIG. 1 will be explained in accordance with the flow of card processing.

First, the card 2 stored in the hopper 1 is transferred to the picker 3 according to the timing from the main clock (MC) counter.
is driven and the sheets are fed one by one.

The card 2, which is fed at a constant speed by the rollers 4 and 5, is stopped by the brake leaf spring 13 when the rear end leaves the roller 5.

At this time, the pinch roller 6.7 is in the off state.

The aligner 14 is driven and the guard 2 is positioned.

Laura 4~? , 11, 12, and the eccentric shaft 15 are connected to one motor (hereinafter referred to as main motor) by a synchronous transmission mechanism such as a toothed belt, and are constantly rotating.

A code plate 16 is attached to the eccentric shaft 15, and a main clock (
MC), and a sub-clock divided into even thinner parts (MC)
SC) is taken out, and the state of the device is represented by these two clocks.

The rollers 6.7 are driven via Geneva gears and perform an intermittent feed once per rotation of the eccentric shaft.

Furthermore, after the punch 17 descends and the punch blade hits the paper card 2 and punches it out, the intermittent feed stop time arrives during the time until the punch 17 rises and the blade comes out from the paper card 2. It is synchronized like so.

Further, the rollers 6' and 7' are pinch rollers, and are biased so as to restrain the paper card 2 when the paper card 2 is intermittently fed by an electromagnet or the like.

Rollers 8, 9.10 are driven by DC motors.

The roller 8' is a pinch roller and is energized by an electromagnet or the like at the start of card feeding.

That is, as soon as roller 7' is turned off, roller 8 is turned off.
' is turned on and feeding by the DC motor is started.

The sensor 18 is installed for the purpose of creating a timing to start counting the clock from the code plate 21 attached to the DC motor output shaft in order to stop the card 2 at a predetermined position, and detects the front end of the card 2. .

Therefore, when the front end of the card passes through the sensor 16, the clock from the code plate 21 is counted and the card 2 is stopped at a predetermined position.

The wire dot print head 20 is capable of reciprocating in a direction perpendicular to the plane of the page of FIG.

That is, reciprocating motion is performed using two pairs of electromagnetic clutches and brakes using power from the main motor.

A clutch that drives the carriage is turned on at a certain timing, and printing is performed in accordance with a printing position corresponding to the position of the carriage, and is ejected toward the platen 19.

When the desired number of lines have been printed, the DC motor is restarted and the card 2 is fed.

The processed cards 2 are stored in the stacker 23 or 24 by rotating the rollers 11 and 12 while moving the selection valve 22 up and down.

In this manner, in the apparatus shown in FIG. 1, all operations other than the print carriage operation and the DC motor feeding operation are completely synchronously controlled using the MCO as a reference.

Because the print carriage and DC motor have separate power systems or clutches, perfect synchronization is difficult.

Therefore, in order to synchronize the printing operation with the punching operation, control as shown in FIG. 2 is performed.

That is, the print operation start signal S1 of the last line of the print control PRTCONT is punched 7'f -
)”・After the control PNCHFDCONT detects the counter MCCTR.

Send the reset R8T and start STA signals to SCCTR and set it as MCO.

In addition, when there is no printing, the counter MCCTR, 5
CCTRI/l- is controlled by a predetermined count value.

, FIG. 3 is a mechanical layout diagram of the DC motor, rollers, and code plate.

As mentioned above, D is used as a card feeding mechanism for printing.
A C motor 30 is used, and a pulley is applied to the roller 31 of the main shaft of the DC motor 30, and a belt 32 drives the roller 8.
Rotate.

If the card 2 is inserted with the pinch rollers in contact with the rollers 8, the force of the belt 32 will be transmitted to the card 2 and it will move forward.

Since the moving distance between the rollers 8 and 10 is long, the DC motor 30 is controlled on/off for constant speed control.

This means that the DC motor 30
A current is applied to accelerate the current.

FIGS. 4a, b, and c are explanatory diagrams of a timing extraction method for constant velocity control.

As shown in FIG.
The photoelectric element 33 detects pulses as shown in FIG. 4a from the disk (code plate) 21 at every specific angle Jo.

The time width of this pulse changes depending on the rotational speed of the DC motor 30.

Therefore, the interval T of the timing pulse TP shown in FIG. 4C.

and the interval P between the pulses obtained from the photoelectric element 33.

Acceleration and deceleration are controlled by comparing the

That is, when comparing the time between the pulse interval Po of the photo disk PHD and the timer interval To, in FIG. 4C, the time corresponding to A is P.

is longer and slower than the set time, so only the time width of A is D.
An acceleration current is applied to the C motor 30.

When the pulse interval P of the photo disk PHD decreases due to acceleration and the timer interval T1 becomes longer, if you leave it at 1 without performing any deceleration processing, the tension of the belt 32, etc. The rotation speed of the photo disk PHD decreases.

By performing this at each timing, the speed is controlled.

By the way, an abnormality occurs in the DC motor 30, and Po, P
If t... becomes longer and you try to flow an accelerating current, but the speed does not increase, or every time Po, Pl...
・ is shorter, and if left unattended at 1, it may accelerate too much and make on/off control impossible.

Regarding the former, if we measure the period from when roller 7' is turned off and roller 8' is turned on to when sensor 18 detects the front end of card 2, as shown in FIG. An abnormality can be detected when the speed of 30 does not increase.

However, regarding the latter, the sensor 18 cannot detect the abnormality, and the card 2 is fed at a high speed due to the high speed rotation of the DC motor 30.

The purpose of the present invention is to eliminate such drawbacks by comparing the pulse interval taken out from the photo disk coaxial with the DC motor with the timing pulse interval, and determining that the pulse interval from the photo disk is shorter. In this case, if the motor 30 is left as it is, the motor 30 will be accelerated too much and there is a risk of failure. Therefore, it is necessary to promptly detect this and report an abnormality in the control circuit.

Embodiments of the present invention will be described below with reference to the drawings.

Figure 5 is a block diagram of the rotation speed abnormality detection circuit, Figure 6g
=h is the operation time chart in normal and abnormal conditions in FIG.

As shown in Figure 5, RTG MS is a retrigger monostable multivibrator, MS is a non-retriggerable monostable multivibrator, and PHD is a photo vibrator.
Pulse from disk, EOR is exclusive OR circuit, E
R is an abnormality detection signal, ACCEL is an acceleration instruction signal, Q...
Q is the output when the circuit is on, and Ql is the output when the circuit is off.

As shown in FIG. 5, the abnormal rotation speed abnormality detection circuit of the present invention includes a retriggerable monostable multivibrator RTG MS and a nonretriggerable monostable multivibrator MS. .

Set the MS to the same output time width and send the pulses extracted from the photo disk PHD to both multivibrators RT.
By applying the signal to GMS and MS, the exclusive OR of both outputs is taken to obtain an abnormal output signal ER.

Non-retriggerable monostable multi-vibration M
S is the time width T when an output of a certain time width T is taken out by the first input pulse.

Even if the next input pulse is applied within that time, it will be ignored and turned off immediately.

On the other hand, the retriggerable monostable multivibrator RTGMS takes out an output with a fixed time width T1 due to the first input pulse, but is triggered again when the next input pulse is applied within the time width T1. , an output extended by a certain time width T1 from that point is taken out.

Therefore, if the period of the input pulse is shorter than the time width T, the multivibrator RTG MS remains turned on.

Note that the constant time width T is set to be shorter than the period P of the pulses taken out from the photo disk during normal rotation.

Figure 6 a=d is a time chart for normal operation;
FIG. 6 e=h is a time chart in the case of abnormal rotation operation.

Now, a pulse train P with a normal period P as shown in FIG.
When H1, 2, 3... are extracted from the photo disk by a photoelectric element and applied to a retriggerable monostable multivibrator RTG MS and a nonretriggerable monostaple multivibrator MS, the respective outputs Q, and Q. A constant time width T as shown in Figure 6, c.

The number becomes “1”.

After the output becomes “O” for time A, the next pulse P is started again.
Since the trigger is applied at H, the reset output Q, of the retriggerable monostable multivibrator RTG MS provides the acceleration instruction signal ACCEL for a time A.

In this case, the output of the exclusive OR of both outputs Q and Q2 is:
As shown in FIG. 6d, it becomes "O"' and no abnormality detection output is given.

Note that here, the output time width T of the non-retriggerable monostable multivibrator MS is taken as the reference timing period, and all cases where the pulse interval P1 taken out from the photo disk is longer than the standard timing period are considered to be normal conditions. .

Next, if too much accelerating current flows in the DC motor 30 and a failure occurs, the pulse train P H1', 2', 3', etc. with an abnormal period Po as shown in Fig. 6e will be generated. Removed from the photo disc, both multivibrators RTG
MS, added to MS.

The retriggerable multivibrator RTGMS is the 6th
As shown in FIG. f, the re-trigger is applied within the output time width T1, so the output Q1 remains at "1"'.

On the other hand, the multivibrator MS that cannot be retriggered is the sixth
As shown in Fig. g, pulses input within the output time width T3 are ignored, so the time width T, the turn-on time, and the time width P.

Repeat take-off. When the exclusive OR of both outputs Q and Q is taken, as shown in Figure 6, the outputs "1" and 1 and the abnormality detection signal E are output only during the time when the waveforms of both outputs Q1 and Q do not match.
Send R to the control device.

Upon receiving the abnormality detection signal ER, the control device immediately stops driving the DC motor 30, checks whether the abnormality is in the control device or the DC motor 30, and takes some kind of action.

As described above, according to the present invention, when the DC motor is accelerated too much and on/off control becomes impossible, an abnormality in the rotation speed of the motor is detected and immediately reported to the control device.
Abnormal conditions in the control device or DC motor can be quickly discovered and appropriate measures can be taken.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of the mechanical part of the paper card punch printing device, Figure 2 is a block diagram of the synchronization circuit for the printing system and punch system in Figure 1, and Figure 3 is the DC motor, roller and Mechanism layout diagram of the code plate (photo disk), Figures 4a, b, and c are explanatory diagrams of the timing extraction method for constant velocity control, and Figure 5 is a rotation speed abnormality detection circuit showing an embodiment of the present invention. The block diagram of FIG. 6, a=h, is an operation time chart in normal and abnormal conditions in FIG. PHD...Photo disc, RTG MS...
Retrigger Monostable Multivibrator MS・
...Monostable multivibrator that cannot be retriggered, ACCEL...acceleration instruction signal, FOR...exclusive OR circuit, traction...abnormality detection signal, T. . . . Reference timing period, Po . . . Pulse period from the photo disk at abnormal times, P, . . . Pulse period from the photo disk at normal times.

Claims (1)

[Claims] 1. In a circuit that extracts pulses at specific angles from a code plate installed coaxially with the motor, and compares the interval of the pulses with the pulse width of a reference timer to control the rotational speed of the motor on and off. Provide retriggerable and non-retriggerable monostable circuits that provide outputs at the same time interval by applying pulses extracted from the code plate, and a circuit that XORs the outputs of the two vehicle stabilizer circuits. A rotation speed abnormality detection circuit for on/off control featuring: