JPS63297043A - Ink supply quantity controller per zone - Google Patents

Abstract

PURPOSE:To prevent the increase of ink temperature from occurring due to the heat generation in a stepping motor, by a method wherein the abnormal control of the stepping motor is judged according to a condition of pulse signals generated from a corresponding pulse generator according to a condition detected by a detecting means and the drive of the stepping motor and the condition detected by the detecting means. CONSTITUTION:If the increase/decrease of blade open amount is directed by switches 111-11n, a CPU 21 issues data directing which blade open amount should be increased/ decreased, and this data is imparted to a CPU 31. After selecting a DRV 4 by sending a control signal ME through an I/F 35 and a selection signal MC through an I/F 36, the CPU 31 sends a forward or reverse rotation pulse PF or PR from the I/F 35, whereby a stepping motor (STM) 41 rotates to conduct the increase/decrease of blade open amount. A pulse generator 42 also rotates in synchronism with the STM 41 to issue pulse signals phia, phib and a detection signal H. With the normal generation of signals phiA, phiB, the CPU 31 judges the STM 41 to be free from a step-out according to a drive pulse under normal control and judges an exciting condition to be also normal according to the detection signal H, and a sub-control part judges whether an error is generated.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a device for electrically controlling the amount of ink supplied for each zone divided in the horizontal direction of a printing plate mounted on a printing cylinder of a printing press. It is related to.

[Conventional technology]

In printing presses, in order to continuously supply the appropriate amount of ink to the printing plates mounted on the printing cylinder, blades are provided for each zone of the printing plate, facing the ink roller of the ink fountain, and the ink roller and each blade In the past, for the purpose of controlling the amount of ink supplied to each zone of the printing plate by adjusting the opening amount between the , a motor for adjusting the opening amount is provided for each blade, as well as a potentiometer that converts the opening amount into an electrical signal, and these constitute a DC servo control circuit that uses the opening amount as a feedback signal, thereby controlling the opening amount for each zone. Ink supply amount control is performed.

However, with the above configuration, the durability of the servo motor and potentiometer, changes in characteristics over time, impedance fluctuations of the connection line, electrical noise, etc. are affected, and control accuracy and stability are insufficient. ing.

As a countermeasure, we used a step motor instead of the analog control described above, and digitized the control circuit.
Consideration has been given to achieving a highly accurate and highly stable control situation.

[Problem that the invention seeks to solve]

However, if a step motor is left running with an excitation current in a stopped state, it will generate a large static torque, but it will also generate heat, and if an unnecessary excitation current is left running through multiple step motors, this heat generation will be caused by The temperature of the ink in the ink bag increases and the viscosity decreases, so the amount of ink supplied increases at the same blade opening and ink roller rotation speed. The amount of ink adhering to the printed matter becomes large, causing problems such as changes in print density and printing defects.

Note that the flow of unnecessary excitation current is caused by an abnormality in the control status of the control circuit or an abnormality in the drive circuit of the step motor, so monitor the excitation current flow status of the step motor and check the control status of the step motor. There is a growing demand for a method that can immediately determine that an abnormality has occurred.

[Means for solving problems]

In order to solve the above-mentioned problem, the present invention uses the following means! It has become a reality.

That is, in a device that performs the above-mentioned control using a step motor, a pulse generator that is connected to each step motor and generates a two-phase pulse signal corresponding to the rotation, and a power source for each step motor are provided. A switch circuit that turns on and off, a detection means that detects the excitation current for each step motor, and a pulse generator that corresponds to the detection status by the corresponding detection means when the switch circuit is turned on and the drive of the step motor. The stepper motor is equipped with a control means that determines whether there is an abnormality in the control of the step motor according to the situation of the generated pulse-like signal and the situation detected by the detection means.

[For production]

Therefore, if a detected force is generated immediately after turning on the switch circuit, it is an abnormal flow of excitation current, whereas if a pulse-like signal is not generated and no detected force is generated when the step motor is driven, This means that the excitation current is not flowing, and it can be immediately determined from these results that an abnormality has occurred in the control status of the step motor.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to figures showing practical examples.

FIG. 1 is a block diagram showing the configuration. On the operation panel (hereinafter referred to as 0P) 1, there are switches 1'1 for adjusting the opening amount of the blade, corresponding to each zone divided in the left and right direction of the printing plate. ~11
n is provided, and an indicator 12 such as a bar indicator that displays each blade opening I is provided above and opposite to these.
□~12n are provided, and the main control unit (
The MCT (hereinafter referred to as MCT) 2 mainly includes a processor (hereinafter referred to as CPU) 21 such as a microprocessor, and a ROM (Read
0nly Memory, ) and RAM (Rand
om Access M@mory, ) by memory (
Hereinafter, MM) 22 and interfaces ((hereinafter, r/F) 23 to 25 are arranged around the busbar 2
6, and the CPU 21 is connected to the R of MM22.
Executes the instructions stored in OM and transfers the required data to M
Predetermined data processing is performed while accessing the RAM of M22.

Further, the sub-control unit (hereinafter referred to as 5CT) 3 connected via the I/F 24 of the MCT 2 is also configured with a CPU 31 similar to the CPU 21, an MM 32 similar to the MM 22, and I/Fs 33 to 36. The busbar 3T
9, CPU31 is connected to CPU21
Predetermined control is performed through processing operations similar to those described above.

Note that the 5CT3 is provided with an indicator light (hereinafter referred to as PL) 37 including a drive circuit, which indicates the occurrence of an abnormality due to breakage.

For these, drive units (hereinafter referred to as DRY) 4, ~4n are provided for each blade of Innakayoshi, and these
switches 11, ~11n and indicators 12, ~12n
As shown in the representative DRV4, there is a step motor (hereinafter referred to as STM) 41 that adjusts the opening of each blade of the ink fountain individually, and a pulse generator such as a resolver connected to this (STM). PC) 42, and a selection signal M sent from the I/F'36 of the 5CT3.
In response to C being applied via the buffer 43, the gates 46 to 52 of 2 are turned on, and excitation is performed according to the forward rotation pulse PF' or reverse rotation pulse PR for driving sent through the I/F 35 of the 5CT3. Pattern generator (hereinafter referred to as E
A driver (hereinafter referred to as DR) 54 drives the STM 41 based on an excitation signal generated by the PG) 53, causing it to rotate in a stepwise manner.

In response to this rotation, the PG42 also rotates at the same time and generates two-phase pulsed signals φa and φb having a phase difference of 90 degrees, similar to a two-phase rotary encoder. The waveform is shaped by the gates 44 and 45 with the characteristics, and the two-phase pulse signals φA and φB are output to the I/F 34 of 5CT3.
given to.

In addition, a resistor R□ is inserted in the power return path of the DR54, and the terminal voltage of this generated in response to the four drive currents of the STM41 is sent out as the excitation detection signal H via the AND gate 48, and the While supplying power to I/F34, turn on and off the power supply V of STM41, and connect resistor R1.
In order to apply the power supply V to the STM41 via l,
A switch circuit (hereinafter referred to as 5W) 55 using switching elements such as transistors is provided, and the I/F of 5CT3
The SW 55 is turned on in response to the control signal ME sent from the SW 35, and the STM 41 is driven in this state, and after this is completed, the sws is turned off again.

Therefore, if the switches 11□ to 11n of OPl are used to increase or decrease the blade opening J, this data will be 1/F2.
3 to the CPU 21, and in response, the CPU
U21 sends data on which blade opening should be increased or decreased via I/F24, and this is the I/F24.
When given to CPU31 via /F33, CPU3
1 is the control signal ME sending from r/F'35 and I/
Control by sending selection signal MC via F36!
After selecting DRV4, forward pulse PF is sent from I/F35.
4 or reverse pulse PR as the number of pulses corresponding to the amount of increase or decrease in opening of the lid, and by n,
The STM 41 is driven via the EPG 53 and the 0R 54, and the STM 41 rotates in steps according to the number of pulses, thereby controlling the opening of the blade.

Then, the PG42 also rotates in synchronization with the rotation of the STM41, and sends out pulsed signals φa and φb indicating the situation, and also outputs a detection signal H in response to the four drive currents of the DR54.
If the pulse signals φA and φB via the I/F 34 are generated normally, the CPU 31
It is determined that TM41 does not rotate according to the driving pulse and the control status is normal, and the excitation status is also determined to be normal according to the detection signal H, and the sub-control unit determines that an error has occurred. If an error occurs, an error signal is sent to the main control section, and the main control section receives the signal and displays an error message.

The blade open lid display on the OPl is shown by switch 11 on the OPl.
, ~11n.

The above control is performed sequentially and repeatedly at high speed for the DRV4, ~4n, and each DRV4□
Control over the cards and display on the displays 12□ to 12n are performed.

In addition, the I/F 25 is used for exchanging data with other parts, and the CPU 21 also performs processing corresponding to this data.

FIG. 2 is a perspective view showing the structure of the DRV4.
is fixed, and is directly connected to PG4.
2 is fixed, a gear 63 is engaged with a shaft passing through a mounting plate 61 of a gear box 62, and a gear 64 that engages with the gear 63 is connected to a known blade opening adjustment mechanism (not shown in the figure). It is intended to drive the

Furthermore, a support 65 is fixed to the STM41 side of the mounting plate 61, protruding parallel to the STM41, etc., and a printed circuit board 66 on which each circuit of the DRV4 shown in FIG. 1 is mounted is attached to the STM41 side. It has been stopped.

Fig. 3 is a 70-chart showing the control status mainly performed by the CPU 31 of the 5CT3.
Excitation abnormality flag set? Check J 101,
Assuming that this is N (No), the control signal ME
, turn on 5W55, perform "Turn on the motor/power supply ON J102, and judge [[Motor/excited? 4103]" based on the detection signal H. If this is N, it is normal. Check the corresponding motor error 7 lag set?J 111, and in response to the N of this, perform the ``Select the concerned motor'' 112 by sending the selection signal MC, and then ``Send 1 step of PF or PR'' 113 In this case, the number of driving pulses required for 87M41 to rotate one step is sent out, and the pulse signals ``φA, φ
B. Regular? Judging J 114.

When the result of step 114 is Y (YES), MM3
After performing [Current position data / 1 stamp update J121] in 2, the selection signal MC is stopped and the corresponding motor selection stop is performed 122, and the sending of the control signal ME is stopped and the SW55 is turned off. Motor/Electric [OF
After performing FJ 123, repeat steps 101 and subsequent steps for the next rank 87M41 via (-ENDJ).

For the above, if step 114 is N, the pulse signals φA and φB are not generated normally, and the rotation of 87M41 is abnormal.To find the cause of this, the same question as in step 101 is displayed: ``Is the motor excited?'' ” 131, and according to this Y, the flow of excitation current is normal, so it is determined that it is a tax adjustment, and “Set the motor error flag” 132 corresponding to step 111 is performed, and MCT 2
Data indicating the error is sent to the motor controller 133, and the corresponding display 12 of the OPl is blinked or the display color is changed to notify the operator of the occurrence of an abnormality in the control.

On the other hand, if step 103 is Y or step 131 is N,
It is determined that the excitation current is not normal and the excitation status is abnormal, and in response to step 101, "Set the motor/excitation abnormality flag" 141 is performed, and the PL of 5CT3 is set.
37 is turned on and an "excitation abnormality display" 142 is performed, then the process moves to step 132.

Therefore, a control abnormality in the 87M41 is immediately and reliably determined, and this is notified to the operator.
Since it is clear whether the rotational abnormality is due to the abnormal excitation status or the rotational abnormality due to the tax adjustment, it becomes easier to repair the faulty part based on these judgments.

Moreover, by taking immediate action in response to the occurrence of an abnormality, the temperature rise of the ink fountain due to heat generation of 87M41 due to unnecessary flow of excitation current is prevented, and printing defects due to decrease in ink viscosity are prevented.

Incidentally, since the PG 42 generates the pulse-like signals φa and φb of the sine phase, it is possible to accurately detect the tax adjustment even if a hunting pulse occurs.

Furthermore, since the two-phase pulse signals φA and φB are used only to detect the tax adjustment, it is not a closed loop control, and there is no control error caused by noise, etc., and the 87M41 is not forced to rotate by some external force. In this case, since the rotation direction and rotation angle are indicated by each pulse signal φA and φB, it is optional to obtain the position deviation by comparing it with the data in MM32 and correct the position deviation accordingly. .

In addition, 87M41 has no brush and PG4
No. 2 has no mechanical contacts such as a potentiometer, which improves overall durability and stability, and provides high reliability.

On the other hand, by using 87M41, the opening control is accurate and 6
Furthermore, if the number of steps of the aTM41 is increased by 10 times or more for the minimum unit operation command, control accuracy and reproducibility will be improved, and the DRV4 will have no mechanical restrictions on the control origin, and the blade opening will be reduced. The control origin can be set independently of the adjustment origin of the adjustment mechanism.

In addition, if you directly combine PG42 with 87M41,
There is no delay in the generation of the pulse signals φa and φb corresponding to the rotation of the 87M41, and the detection based on this is quick.

The means for obtaining the excitation current detection signal H is the resistor R.
In addition to 1, selection can be made arbitrarily depending on the situation, while S
TM41 can also be used as an ultrasonic driven motor (PG
42 may be used as a photoelectric pulse encoder, the printed circuit board 66 in FIG. 2 may be omitted, and it may be housed integrally in the 5CTa in FIG. 1. The configurations in FIGS. Various modifications are possible, such as arbitrary selection depending on the situation.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, when controlling the ink supply amount by zone based on blade engagement using a step motor, it is possible to reliably detect four unnecessary excitation currents of the step motor. At the same time, the cause of the step motor control abnormality can be determined, which prevents the ink temperature from rising due to the step motor's heat generation.
It is easy to prevent printing defects, and a remarkable effect can be obtained in controlling the ink supply amount by zone of various printing machines.

[Brief explanation of drawings]

The figures show an embodiment of the invention, FIG. 1 is II! FIG. 2 is a perspective view of the drive unit, and FIG. 3 is a flowchart of the control situation. Blind...op (operation panel), 2...MCT (main control section), 3...SCT (sub control section), 4-4 ・
・・・DRY (Driver input 21.31...n ･･CPU (7' processor), 22.32... Take (memo +7), 41 ･･･STM (step motor), 42... ...PG (pulse generator), 44-52
...AND gate, 55...SW (switch circuit), R1*R1...Resistor, H...Excitation detection signal, PF...Forward rotation pulse, PR...・Reverse pulse, φa, φb ... Pulse signal, φA, φ
B...Pulse signal.

Claims (1)

[Claims] In the apparatus for controlling the ink supply amount for each zone by individually adjusting the opening amount of each blade provided in each zone obtained by dividing the left and right direction of the printing plate by a step motor corresponding to each blade, each of the step motors a pulse generator that is connected to each of the step motors and generates a two-phase pulse signal corresponding to the rotation; a switch circuit that turns on and off the power for each of the step motors; and a switch circuit that controls the excitation current for each of the step motors. A detection means to detect, a detection situation by the corresponding detection means when the switch circuit is turned on, a situation of a pulse-like signal generated from the pulse generator corresponding to driving of the step motor, and a detection state by the detection means 1. A zone-based ink supply amount control device, comprising: a control means for determining abnormal control of the step motor according to the situation.