JPS5849252A - Detecting method for wetting water in litho printer - Google Patents

Abstract

PURPOSE:To obtain a printed matter of a high quality which keeps excellent stability for a long period of time, by a method wherein an electrode is attached to a water transfer roller and water-wetting rollers to detect a wetting water amount through measurement of impedance, and this adjusts a feed amount thereof. CONSTITUTION:An electrode is attached to a water transfer roller 2 covered with a water-containing layer 5 such as molton and water-wetting rollers 4 or a roller, i.e., a dampening roller, having the same function as that of aforesaid rollers, and a water-wetting amount is detected by measuring impedance generated between the electrodes through application of an AC voltage to the electrodes. The AC voltage applied at a measuring time has preferably a constant- frequency ranging within 100Hz-10kHz. It is advisable that the electrodes are attached across the dampening roller.

Description

【発明の詳細な説明】 本発明は平版印刷機における湿し水検知方法に関する。[Detailed description of the invention] The present invention relates to a method for detecting dampening water in a lithographic printing press.

平版印刷において湿し水量の程度社印刷物の品質に大き
な影響を及ぼす。従って印刷操作中湿し水量音検知しこ
れ１一定に保つことは極めて重要である。In lithographic printing, the amount of dampening water has a great effect on the quality of printed matter. Therefore, it is extremely important to detect the amount of dampening water and keep it constant during printing operations.

従来、湿し水量の検知、制御は、印刷物や印刷中の版の
光沢を肉眼で観察する方法が主にとられてきたが、近時
熟練を要しない種々の方法が提案されてきている。Conventionally, the amount of dampening water has been mainly detected and controlled by visually observing the gloss of printed matter or plates during printing, but recently various methods that do not require skill have been proposed.

その一つは、米国特許第３．４３９，１７５号、特公昭
５２−１７７６１号その他にみられる印刷版面上の水膜
を光の反射蓋変化で測定する方法でめる。この方法は印
刷機の印刷版表面上のごく薄い水膜の厚さを光の反射に
より測定するものだが、光源出力の紅時変化、受光部の
インキや油の飛沫や紙粉による汚れ、版胴の回転による
プレ、印刷版面の不均一等多くの測定技術上の問題点の
他、経済性、印刷作業の障害になるような機器配置の必
要等の問題点を有し実用化には至っていない。One of them is the method of measuring the water film on the printing plate surface by the change in the reflection cover of light, which is found in US Pat. No. 3,439,175, Japanese Patent Publication No. 52-17761, and others. This method measures the thickness of a very thin water film on the surface of a printing plate in a printing press by reflecting light. In addition to many measurement technology problems such as pressure caused by rotation of the cylinder and uneven printing plate surface, there are also problems such as economical efficiency and the need for equipment layout that may interfere with printing operations, so it has not been put into practical use. not present.

他の方法として社、特公昭３６−３０２５号、特開昭５
０−４２９０８号に開示され次ダンプニング用ローラｏ
含水ｉを電気抵抗変化で検知する方法及び特開昭５０−
１４４５１２号に開示された電気容量変化で検知する方
法が知られている。Other methods include Sha, Japanese Patent Publication No. 36-3025,
No. 0-42908 discloses the following dampening roller o
Method for detecting water content i by electrical resistance change and JP-A-1987-
A method of detecting by a change in capacitance is known, as disclosed in Japanese Patent No. 144512.

しかし電気抵抗をノイズなしに単独で測定することはか
なシ困難でる損得られる結果に再現性と信頼性會期待す
ることはむづかしい。このこと社電気容量についても同
様である。However, it is difficult to measure electrical resistance independently without noise, and it is difficult to expect reproducibility and reliability of the results obtained. This also applies to the electrical capacity.

また従来知られた電気抵抗変化で検知する方法及び電気
容量変化で軽動する方法で用いられている装Ｗｔはいづ
れも印刷効果や作業性に問題ｔ−有し経済性よく長期間
安定に高品質の印刷物を得ることは期待し難い。In addition, the devices used in the conventional methods of detecting changes in electrical resistance and methods that use light movement based on changes in capacitance both have problems with printing effectiveness and workability, and are economical and stable over a long period of time. It is difficult to expect to obtain quality prints.

・本発明者等は簡単な手段によシ、湿し水量の変化を正
確且つ再現性よく検知できる方法を開発すべく鋭意検討
した結果、効果の顕著な本発明に到達した。- The inventors of the present invention have conducted intensive studies to develop a method that can accurately and reproducibly detect changes in the amount of dampening water using simple means, and as a result, have arrived at the highly effective present invention.

即ち本発明はダンプニング用ローラまたはこれと同等の
機能を有する湿し水検出用ローラに電極を設け、該電極
に交流電圧を加えて該電極間のインピーダンス・全測定
することによジインピーダンスの変化に応じて湿し水量
の５化を検知する方法全提供するものであシ、これによ
シ常に一定量の湿し水をダンプニング用ローラに供給す
ることができる。That is, the present invention provides an electrode on a dampening roller or a dampening water detection roller having an equivalent function, and measures the impedance between the electrodes by applying an alternating current voltage to the electrode, thereby determining the diimpedance. The present invention provides a method for detecting a change in the amount of dampening water depending on the change, so that a constant amount of dampening water can always be supplied to the dampening roller.

第１図は平版印刷機における代表的な給水装置の一例を
示す概略断面図である。FIG. 1 is a schematic cross-sectional view showing an example of a typical water supply device in a lithographic printing press.

水元ローラ１は、水舟の中に浸してお）、印刷機本体の
回転と連動さ瓢連続回転または間欠的に回転し、印刷機
本体のスピードにしたがって回転する。また、印刷機本
体スピードに関係なく、単独のモ４−ター駆動によって
回転するものとがある。いずれも、無段階で微調整がで
きる。The water base roller 1 is immersed in a water tank) and rotates continuously or intermittently in conjunction with the rotation of the printing press main body, and rotates according to the speed of the printing press main body. In addition, there are some machines that are rotated by a single motor, regardless of the speed of the main body of the printing machine. Both can be fine-tuned steplessly.

湿し水の量は、水元ローラの回転によシ決定される。部
分的す：ｆｆ／）ロールは、水元ローラの水膜を水切シ
で遮断して行う。版面の湿し水の状態を確認しながら水
元ローラの回転２：１７）。−ルすることが、大きなポ
イントといえる。The amount of dampening water is determined by the rotation of the fountain roller. Partial rolling is performed by blocking the water film on the water base roller with a drainer. While checking the condition of the dampening water on the printing plate, rotate the water roller at 2:17). -The key point is to follow the rules.

水移しローラ２は、水元ローラ１と水振りｉ−ラ３の間
で、定期的に往復運動上行って接触しながら回転し、水
元ローラから水振りローラへ、湿し水の転移全行うもの
である。The water transfer roller 2 rotates between the water base roller 1 and the water shaker roller 3 while periodically reciprocating and in contact with each other, and transfers dampening water from the water base roller to the water shaker roller. It is something to do.

このローラは、通常モルトン被覆ＳＫしている。This roller is usually Molton coated SK.

水振りローラ３ｉｔ湿し水のならしの役目上するために
軸方向に往復運動を行うとともに、水着はローラ４に回
転を与える役目をしているので、水損ジローラ３の表面
速度は版面速度と一致している。Water shaker roller 3It performs a reciprocating motion in the axial direction to level out the dampening water, and the water roller 3 has the role of giving rotation to the roller 4, so the surface speed of the water damage roller 3 is the plate surface speed. is consistent with

水着はロー２４は、水振りローラ３との接触で回転し通
常は上下の２本で、モルトンまたはスリーブ（紙）の被
覆をし保水性金持ち版面６に湿し水金供給している。The rows 24 of the swimsuit are rotated by contact with the water shaking roller 3, and usually have two upper and lower rows, which are covered with Molten or sleeve (paper) and supply dampening water to the water-retaining rich plate surface 6.

水移しロー２２と水着はローラ４は前記したようにモル
トンなどの含水層で横われてお広この部分に含まれる水
量と版面６に供給される湿し水量とは比例関係にある。As described above, the water transfer row 22 and the swimsuit roller 4 are covered with a water-containing layer such as Molton, and the amount of water contained in the wide portion and the amount of dampening water supplied to the printing plate 6 are in a proportional relationship.

本発＃！ＡＦｉダンプニング用ロー２即ち上記のモルト
ｙなどの含水層で覆われた水移しローラ２または水着は
ロー２４−またはそれと同等の機能ｔ−有する湿し水検
知用ローラに電極を設けてインピーダンスを測定するこ
とにより、湿し水量？検知し制御するものである。Main departure #! The AFi dampening roller 2, that is, the water transfer roller 2 covered with a water-containing layer such as the above-mentioned malt y, or the swimwear roller 24- or a dampening water detection roller having an equivalent function t- is provided with an electrode to increase the impedance. By measuring the amount of dampening water? It is something that is detected and controlled.

モルト７等の含水層を有するダンプニング用ロー２の含
水量ＭとインピーダンスＺとの関係を図示すると第２図
の如くなシ、極めて精度よい相関が認められる。第２図
から明らかなように、含水蓋Ｍが増えるに従ってインピ
ーダンスＺは減少する。周波数と感度（へｌ／１ｍ　）
の関係は第３図の如くである（ここで感度は１００　Ｈ
ｚの時のへ”／ｍ　ｔ−１００として計算した）。第３
図において斜線部は測定周波数が１０　Ｑ＃ｇ以下では
主に電源および印刷機自体の低周波ノイズや波形歪等の
影響があルまた１１００ＫＨ以上では付近の作業者等の
容量ノイズの影響等があり、測定が不安定で信頼性に欠
けることｔ意味する。When the relationship between the water content M of the dampening row 2 having a water-containing layer such as malt 7 and the impedance Z is shown in FIG. 2, an extremely accurate correlation is observed. As is clear from FIG. 2, the impedance Z decreases as the number of water-containing lids M increases. Frequency and sensitivity (l/1m)
The relationship is as shown in Figure 3 (here, the sensitivity is 100 H
z time”/m t-100).3rd
In the diagram, the shaded area indicates the measurement frequency below 10Q#g, which is mainly affected by low frequency noise and waveform distortion of the power supply and printing machine itself, and above 1100KH, which is affected by capacitance noise from nearby workers, etc. This means that the measurement is unstable and unreliable.

第２図及び第３図の結果はいづれも、ダンプニング用ロ
ーラの含水層と接する内面の両端に電極を設けた装置を
使用して測定した本のであるが、この装置の一例を第４
図に示す。The results shown in Figures 2 and 3 were measured using a device that had electrodes on both ends of the inner surface of the dampening roller in contact with the water-containing layer.
As shown in the figure.

通常のダンプニング用ローラはモルトン５の内面は絶縁
性ゴムローラ７で構成されている〃ζ第４図ではその端
部を取り去り、その部分に導ｉｌＬ性ゴム電極８ｔ−配
している。９は１７−ドＩ＆！を示す。電極８Ｉ／′ｉ
導電性ゴムに限らず、金属箔、導電性ペイントなど導体
であればいづれでもよい。またローラ円周の一部のみに
１１Ｌ極部を設けてもよく、さらにはローラの長さ方向
の実質上全体を電極で構成してもよい。通常は図示する
ように端部円周に設けることが好ましい。The inner surface of a normal dampening roller is made up of an insulating rubber roller 7. In FIG. 4, the end of the roller is removed and a conductive rubber electrode 8t is placed on that part. 9 is 17-do I&! shows. Electrode 8I/'i
The material is not limited to conductive rubber, but any conductive material such as metal foil or conductive paint may be used. Further, the 11L pole portion may be provided only on a part of the circumference of the roller, and furthermore, substantially the entire length of the roller may be constituted by electrodes. Usually, it is preferable to provide it at the end circumference as shown in the figure.

ローラの長軸方向に測った電極間距離りとローラの直径
０の比Ｌ／Ｄが大きくなるほど、第２図に示す如く、イ
ンピーダンスは大きくなりその感度が向上す５ることが
らも、第４図に示すように、測定用電極はダンプニング
ローラの長袖方向にできるだけ離して設置することが望
ましい。またダンプニング用ローラの長軸方向の一部に
別途湿し水検出用ローラを接触させそのローラに電極を
設置してもよい力ζこのようにすると長軸方向に含水量
のムラが生じやすい。尚、平版印刷機で社印刷版の切れ
目であるギャップが存在し、これが周期的にスパイク状
のノイズを発生させた広回転に伴なう電極の接触ムシ金
主ずるので、これら全除去するために、測定回路にノイ
ズ除去フィルターを組み込むことが好ましい。As the ratio L/D between the distance between the electrodes measured in the long axis direction of the roller and the roller diameter 0 increases, as shown in FIG. 2, the impedance increases and the sensitivity improves. As shown in the figure, it is desirable to install the measurement electrodes as far away as possible in the long sleeve direction of the dampening roller. Alternatively, a dampening water detection roller may be placed in contact with a part of the dampening roller in the long axis direction, and an electrode may be installed on that roller. If this is done, unevenness in water content is likely to occur in the long axis direction. . In addition, there are gaps in the printing plates in lithographic printing machines, and these are the main cause of the electrode contact caused by wide rotation, which causes periodic spike-like noise, so in order to completely remove them. In this case, it is preferable to incorporate a noise removal filter into the measurement circuit.

印刷工場における連続運転では、工場内の雰囲気変動や
モルトンの経時変化（よごれ）などがある力ζこの現象
はその性質上一定の方向に徐々に変化するものであるか
ら、直前のデータを含めた数ケのデータの変化状態上参
考にして、次の設定点を定めるといういわゆる「マルコ
フ鎖」的取扱いをすればよく、簡単な論理回路を作成し
ておけば自動的に最適設定値にプリセットすることもで
きる。During continuous operation in a printing factory, there are changes in the atmosphere within the factory, changes over time (fouling), etc. Since this phenomenon, by its nature, changes gradually in a fixed direction, it is important to include the previous data. All you have to do is use a so-called "Markov chain" method, which refers to the changing state of several pieces of data and determines the next set point. If you create a simple logic circuit, it will automatically preset to the optimal setting value. You can also do that.

第５図に簡単な一つの回路例を示す。印刷条件や作業条
件上、湿し水の組成やｐＨが大幅に変動する恐れのある
場合や温度変動に対しては、第５図に示すように、導電
率センサー（水槽に浸した電極１４など）や温度センサ
ー（サーミスタ１５など）ｔ−回路内に組み込み、セン
サーの特性係数を適当に選んで測定回路を補償すること
ができる。FIG. 5 shows a simple circuit example. If the composition or pH of the dampening solution is likely to change significantly due to printing or working conditions, or if the temperature fluctuates, use a conductivity sensor (such as the electrode 14 immersed in a water tank) as shown in Figure 5. ) or a temperature sensor (such as thermistor 15) can be integrated into the t-circuit, and the measuring circuit can be compensated by suitably choosing the characteristic coefficients of the sensor.

本発明方法に従かえば、電極間の電圧と電流の測定から
簡単に求められるインピーダンスがモルトン等の含水ｍ
ｕ−有ｆるダンプニング用ローラの含水量と精度よい相
関を有する結果、簡単に含水量の変化をインピーダンス
の変化として検知でき、その量ｒ調節することができる
。特にダンプニング用ローラの含水層の実用上の最適値
に対応するインピーダンス社十分な感度と測定精度を有
していることが確認された。According to the method of the present invention, the impedance that can be easily determined from the measurement of the voltage and current between the electrodes can be adjusted to
As a result of having a precise correlation with the water content of the dampening roller, a change in water content can be easily detected as a change in impedance, and the amount r can be adjusted. In particular, it was confirmed that Impedance has sufficient sensitivity and measurement accuracy to correspond to the practical optimum value of the water-containing layer of a dampening roller.

実施例 印刷機として小森スプリントレー４２５８Ｐ　ｋ用い、
印刷紙として山場国策パルプ１＃ＳＫコートを用ペモル
トンとして加貫ローラ製作所製ニューモールを用い、第
１図に示す給水装置の上部のダンプニング用ロー２４と
してＬ／Ｄカ６３０１１１Ｉ／６２簡の第４図に示すダ
ンプニング用ローラを用い、印刷回転数５ＦＣＨｚの条
件で、インピーダンスが一定値を示すように水元ローラ
への給水量ｔｍ節しつつ印刷上行なった。その時のイン
ピーダンスの変動を第６図に示す。印刷枚数５０００枚
以上になっても印線］物の品質に変化＃′ｉＭめられな
かった。Komori Sprintray 4258Pk was used as an example printing machine,
Yamaba Kokusaku Pulp 1#SK coat was used as the printing paper, New Molle made by Kanuki Roller Seisakusho was used as the pemolton, and L/D Ka630111I/62 sheet No. Using the dampening roller shown in FIG. 4, printing was carried out under the conditions of a printing rotation speed of 5 FCHz and with the amount of water supplied to the water base roller set at tm such that the impedance showed a constant value. Figure 6 shows the impedance fluctuation at that time. Even after printing more than 5,000 sheets, no change was noticed in the quality of the prints.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は平版印刷機における給水装置の一例を示す概略
断面図、第２図はインピーダンスと含水量との関係を示
す線図、第３図は周波数と感度との関係を示す線図、第
４図は本発明で用いるダンプニング用ローラの一例を示
す部分切開斜視図、第５図は回路図の一例を示し第６図
は実施例におけるインピーダンスの変動を示す線図であ
る。 １・・・・・・水元ローラ、２・・・・・・水移しロー
ラ、３・・・・・・水振りローラ、４・・・・・・水着
はローラ、５・・・・・・モルトン、６・−・・・・版
面、７・・・・・・絶縁性ゴムローラ、８・−・・・導
電性ゴム電極、９・・・・・・リード線、１０・−・・
・・カーボン、１１・・・・・・絶Ｉｌ性物質、１２・
−・・・・バネ、１３・・・・・・検知用ダンプニング
ローラ、１４・・・・・・電極、１５・・・・・・サー
ミスター、１６・−・・・・水元ローラ調整器。Figure 1 is a schematic sectional view showing an example of a water supply device in a lithographic printing press, Figure 2 is a diagram showing the relationship between impedance and water content, Figure 3 is a diagram showing the relationship between frequency and sensitivity, and Figure 2 is a diagram showing the relationship between impedance and water content. FIG. 4 is a partially cutaway perspective view showing an example of a dampening roller used in the present invention, FIG. 5 is an example of a circuit diagram, and FIG. 6 is a diagram showing impedance fluctuations in the embodiment. 1... Water base roller, 2... Water transfer roller, 3... Water shaking roller, 4... Swimsuit roller, 5...・Multon, 6...Plate surface, 7...Insulating rubber roller, 8...Conductive rubber electrode, 9...Lead wire, 10...
... Carbon, 11 ... Absolute Il substance, 12.
-... Spring, 13... Dampening roller for detection, 14... Electrode, 15... Thermistor, 16... Water head roller adjustment vessel.

Claims (1)

【特許請求の範囲】 １、ダンプニング用ローラま友はこれと同等の機能？有
する湿し水検出用ローラに１を極を設け、該電極に交流
電圧を加えて該電極間のインピーダンスを測定すること
によりインピーダンスの値により湿し水ｉｖ検知するこ
とｉｃ％徴とする平版印刷機における湿し水検知方法。 ２、　１００Ｈｚ　〜１００ＫＺｆｚの範囲の一定周波
数でインピーダンスを測定することを特徴とする特許請
求の範囲第１項記載の方法。 ３、電極をダンプニング用ローラの両端に設けたこと′
Ｊｋ特徴とする特許請求の範囲第１項記載の方法。 ４、電極金ダンプニング用ロー２の表面と接する内面に
設けたことを特徴とする特許請求の範囲第１項記載の方
法。 ５、インピーダンス測定回路にＡズ除去フィルターを組
み込んだことを特徴とする特許請求の範囲第１項記載の
方法。[Claims] 1. Does the dampening roller Mayu have the same function? A lithographic printing method in which a dampening water detection roller having a pole 1 is provided, an alternating current voltage is applied to the electrode, and the impedance between the electrodes is measured to detect the dampening water IV based on the impedance value. How to detect dampening water in a machine. 2. The method according to claim 1, characterized in that the impedance is measured at a constant frequency in the range of 100 Hz to 100 KZfz. 3. Electrodes were provided at both ends of the dampening roller'
A method according to claim 1, characterized in that Jk. 4. The method according to claim 1, wherein the electrode is provided on the inner surface in contact with the surface of the gold dampening row 2. 5. The method according to claim 1, characterized in that an A removal filter is incorporated in the impedance measurement circuit.