JPS6063198A - Additive concentration controller for water used for printing - Google Patents

Abstract

PURPOSE:To maintain the concentration of an additive in a predetermined range, by a method wherein a detecting switch is operated by floating and sinking movements of a gravimeter, and a solenoid valve is driven by a controlling circuit to control the concentration of an additive. CONSTITUTION:The gravimeter 10 is thrown into water 2 contained in a detecting tank 5, and the floating and sinking movements of the gravimeter 10 is detected by the detecting switch PXS. A circular metallic plate for driving the proximity switch PXS is fixed to the tip of a head part of the gravimeter 10. The solenoid valve SV is driven by the controlling circuit operating in response to an output from the switch PXS, and an alcohol is mixed into water from an alcohol tank 7 in accordance with the opened condition of the valve SV.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a device that automatically controls the concentration of additives mixed into water supply for printing.

[Prior art]

In general, printing plates are supplied with ink and moisture during printing.

Particularly in offset printing, the surface tension of the water supply is reduced.
Additives such as alcohol are mixed into the water supply to reduce staining of the plates.

However, the mixing status of additives must be adjusted over time, which makes it difficult to maintain the mixing concentration at an optimal value, and has disadvantages such as excessive consumption of additives, which becomes uneconomical. is occurring.

[Summary of the invention]

The purpose of the present invention is to fundamentally solve such drawbacks of the conventional methods, and in addition to inserting a hydrometer into feed water mixed with additives, a means for driving a detection switch is provided at the head of the hydrometer, and the hydrometer is A detection switch is actuated by the rising and falling motion of the sensor, a control circuit responsive to the output of the detection switch drives an electric valve, and this electric valve controls the concentration of the additive. The present invention provides an additive concentration control device for printing water supply.

〔Example〕

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

FIG. 1 is a block diagram showing a water supply device for printing. In order to keep the printing conditions constant, the water supply 2 in the water tank 1 maintained at a predetermined temperature is pumped into the water tank by a pump P and a water supply pipe 3. 4 and a detection tank 5, and in the water boat 4, a water supply roller (not shown in Figure 1) is used to supply water to a plate cylinder equipped with a printing plate. In detection 4 15 yen, water supply 2 is supplied via cock V for adjusting water volume.

Alcohol supplied from the alcohol tank 7 in response to opening of the solenoid valve SV is mixed in, and when the water level reaches a certain level or higher, it is discharged to the water tank 1 via the drain pipe 8.

In addition, a hydrometer 10 supported by a guide 9 fixed to a drain pipe 8 so as to be able to float and sink is placed in the water supply 2 of the detection tank 5, and when the concentration of alcohol mixed in is reduced, the hydrometer 10 floats to the surface. If the same concentration increases, it will sink, so a proximity switch PXS is provided for the purpose of detecting this floating movement. is movably supported and has an adjusting screw 13
The proximity switch p
The distance between the xs and the tip of the head of the hydrometer 10 is adjustable.

Note that a pointer 14 fixed to the support 11 and a corresponding scale plate 15 fixed to the arm 12 are provided, so that the degree of mixing of alcohol and water becomes a 100-minute ratio. It is clearly shown.

FIG. 2 is an enlarged perspective view of the proximity switch pxs and the head of the hydrometer 10. A circular metal plate 21 for driving the proximity switch PXS is fixed to the tip of the head of the hydrometer 10. The proximity switch PXS is activated by detecting the approach of the metal plate 21 as the hydrometer 10 floats up.

FIG. 3 is an enlarged perspective view of the head of the hydrometer 10 showing another embodiment, in which the sleeve 22 is fixed to the lower surface of the circular metal plate 21 and the sleeve 22 is attached to the tip of the head of the hydrometer 10. However, this is suitable when the head of the hydrometer 10 has a small diameter.

Note that by fixing the metal plate 21 to the hydrometer 10,
If the hydrometer 10 requires a large air chamber volume,
As the hydrometer 10 becomes larger, the width of the floating motion for the same change in specific gravity becomes larger, so that the width of the floating motion becomes about 2 mm for a 1% change in the concentration of alcohol, improving detection accuracy.

Figure 4 is a circuit diagram of the control circuit.
Proximity switch pxs in operating state due to ER
When PXS detects the metal plate 21 and is activated, the internal contact of the switch PXS is turned on, relay R1 is activated, and contact R1 is activated.
, is turned on and AC power @1-@t is applied to relay R2 and timer T1.

Then, relay R2 operates and contacts R2 hold themselves together, so even if the proximity switch PXS (due to sinking of the hydrometer 10) recovers, relay R2 and timer TI continue to operate, and contact R2 , drives the solenoid valve SV to open it and starts supplying alcohol.

Timer TI times up after a certain period of time.

When the contact TI is turned off, the relay R2 is restored, and the solenoid valve SV is also restored accordingly, so the supply of alcohol is stopped, and when the contact TI is turned on, the timer T2 is energized, Contact T2. Regardless of the output of the proximity switch PXS with off.

In order to forcibly restore relay R1, timer T1 is restored.

If the contact Tlt turns off due to the recovery of the timer TI,
The energization of the timer T2 is cut off, but the timer T2 has an integrating circuit or a capacitor, etc., and continues to operate for a predetermined period of time even after the first energization is cut off.

When the detection of the hydrometer 10 by the proximity switch PXS is disabled, the unstable sinking motion of the hydrometer 10 is ignored, and the control state becomes stable.

Note that the amount of alcohol supplied at one time is determined by the set time of the timer T1, and the mixing situation is determined by the amount of alcohol supplied at one time.

It is set depending on the degree of opening of the cock ■.

Therefore, if the concentration of alcohol mixed in the water supply 2 circulating between the water tank 1 and the detection tank 5 decreases, alcohol is automatically supplied, and once the alcohol is supplied, the hydrometer 10 floats and sinks. Even if there is movement.

This is ignored until a predetermined time has elapsed, and the concentration of alcohol mixed in the water supply 2 is kept stably and accurately within a predetermined range, and the printing situation is always maintained in a suitable state.

Further, the concentration of alcohol mixed in is indicated by the pointer 14 and the scale plate 15, and can be finely adjusted using the adjustment screw 13 based on the pointer 14, so that setting of the mixed concentration becomes easy and accurate.

For example, a proximity switch PXSO, a photoelectric switch,
Use an electromagnetic switch etc. as a detection switch.

Accordingly, a driving means corresponding to the metal plate 21 may be used, and the control circuit may be made of a semiconductor element instead of a relay. , a motor valve or the like may be used as an electric valve, and the additive is not limited to alcohol.

Alcohol substitutes, etching liquids, etc. can be selected arbitrarily depending on the situation, and various modifications are possible.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the additive concentration of the printing water supply can be stably and accurately maintained within a predetermined range by simple full construction, and the printing situation can always be kept in an appropriate state. In addition, excessive consumption of additives is prevented, cost savings are achieved, and significant effects are achieved in controlling the concentration of additives in various printing water supplies.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, Fig. 1 is a configuration diagram showing a printing material water supply device, Fig. 2 is an enlarged perspective view of a proximity switch and the head of a hydrometer, and Fig. 3 is another embodiment. FIG. 4 is an enlarged perspective view of the head of the hydrometer, and FIG. 4 is a circuit diagram of the control circuit. 1... Water tank, 2... Water supply, 5... Detection tank,
I...Alcohol tank, 9...Guide, 10...
... Hydrometer, 21 ... Metal disk (driving means), PX
S... Proximity switch (detection switch), SV...
- Solenoid valve (electric valve). R1, R2 --- Relay, TI, T2 --- Timer. Figure 1 Figure 4

Claims (1)

[Scope of Claims] A hydrometer inserted into printing water supply mixed with additives so as to be able to float and sink, a detection switch for detecting floating and sinking movements of the hydrometer, and a detection switch provided at the head of the hydrometer. a drive means for actuating the detection switch; and a control circuit responsive to an output of the detection switch. An additive concentration control device for printing water supply, comprising: an electric valve driven by the control circuit to control the mixed concentration of the additive.