JP2866038B2 - Method and apparatus for cleaning a printing press cylinder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for cleaning a printing press cylinder, such as a blanket cylinder of an offset printing press.

[0002]

2. Description of the Related Art A printing press cylinder such as a blanket cylinder of an offset printing press, if used for a long time, causes paper dust and printing ink to adhere to the printed product, causing stains on printed matter. For this reason, the printing press cylinder is washed every predetermined number of prints. As a cleaning device for a printing press cylinder, a cleaning sheet made of non-woven fabric is wrapped around a pressing portion that can be brought into contact with and separated from the surface of the cylinder, and wiping is performed by pressing a rotating cylinder while spraying and supplying a cleaning liquid to the contact portion. Things are known. Conventionally, this type of cleaning device includes a supply roll on which a cleaning sheet wound in a roll shape is mounted behind a pressing portion having a length equivalent to the body length of a cylinder to be cleaned, and a winding roll for winding. After the washing sheet fed from the supply roll is wound around the pressing portion, the winding roll is intermittently rotated by a predetermined rotation angle to wind up the washing sheet.

[0003] However, the winding method in which the take-up roll is rotated by a predetermined angle and takes up the cleaning sheet wound up by the take-up roll and the roll diameter increases, the winding amount gradually increases. It is uneconomical to wind up the cleaning sheet more than necessary. For this reason, a contrivance has been made to increase the use efficiency of the cleaning sheet by winding the cleaning sheet by a predetermined length. For example, JP-A-1-314173 discloses that a lever attached to a take-up roll is pressed by an air cylinder to perform a take-up operation, and that a take-up roll is wound on a side opposite to a pressing surface of the lever. 2. Description of the Related Art There has been proposed a fixed-size winding device having a structure in which a curved surface for controlling a stroke of an air cylinder is formed by contacting a stopper integrated with a detection body that moves according to a take-up diameter.

[0004]

By the way, in the cleaning of the cylinder, the cleaning sheet is intermittently wound about 10 to 15 times in one cleaning step, and a new portion of the sheet is pressed against the peripheral surface of the cylinder. I try to wipe it out. And in the conventional washing by fixed size winding,
In the case of newspaper printing, etc., the amount of one winding is about 15 mm, and the washing sheet is about 20 cm in one washing step.
I need a degree. However, when observing the cleaning sheet after cleaning the cylinder, a large amount of dirt is observed in the initial stage of cleaning immediately after the cleaning is started, and the dirt on the cylinder surface is reduced as the cleaning proceeds. For this reason, the cleaning sheet had to be wound about 15 mm at first, but in the last part of the washing, it can be sufficiently wiped with a winding amount of about 5 mm. However, the conventional winding amount of the cleaning sheet is determined so as to obtain a cleaning effect in the initial stage of cleaning, and is always wound by about 15 mm from the beginning to the end of cleaning, which is wasteful and uneconomical. Was.

[0005] The present invention has been made to solve the above-mentioned drawbacks of the prior art, and has as its object to improve the use efficiency of a cleaning sheet.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the fact that as the washing progresses, the contamination of the printing press cylinder decreases, and it is not necessary to wind up the washing sheet as early as in the washing, and the washing proceeds. In accordance with the above, the amount of winding of the cleaning sheet is reduced. In other words, the method of cleaning a printing press cylinder according to the present invention is a method of cleaning a printing press cylinder in which a cleaning sheet is intermittently wound and pressed against a rotating printing press cylinder a plurality of times to wipe the surface of the printing press cylinder. A method of winding the cleaning sheet during each pressing contact operation of the cleaning sheet to the printing cylinder, and gradually reducing a winding amount of the cleaning sheet from a cleaning start to a cleaning end. Has become.

Further, the cleaning device for a printing press cylinder according to the present invention has a pressing portion for intermittently winding a cleaning sheet drawn from a supply roll onto a take-up roll and pressing the cleaning sheet against the printing press cylinder. In a cleaning device for a printing press cylinder, a rotation driving unit that intermittently rotates the take-up roll, a winding detection unit that detects an amount of winding of the cleaning sheet onto the take-up roll, A number-of-times detecting means for detecting the number of times the cleaning sheet is pressed against the printing press cylinder, and an output signal of the number-of-times detecting means and the winding detection means are fetched, and the previously given cleaning sheet is pressed against the printing press cylinder. Control means for controlling the amount of winding of the cleaning sheet via the rotation driving means, based on the relationship between the number of times to be performed and the amount of winding of the cleaning sheet; And it has a configuration with. The relationship between the number of times the cleaning sheet is pressed against the cylinder of the printing press and the winding amount of the cleaning sheet is such that the winding amount decreases as the number of pressing times increases.

[0008]

According to the present invention constructed as described above, at the start of cleaning, a large number of cleaning sheets are fed out in the same manner as in the prior art so that a printing press cylinder with much dirt can be sufficiently cleaned, and the last stage of the cleaning process in which the cylinder dirt is reduced. In addition, the feeding amount (winding amount) of the cleaning sheet is reduced. For this reason, in the case of newspaper printing with a lot of stains, it is possible to reduce the amount of use of the cleaning sheet by about 45% in one cleaning step as compared with the related art, and in commercial printing, about 30% of the cleaning sheet is used. Seat usage can be reduced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a method and an apparatus for cleaning a printing press cylinder according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is an explanatory view of an apparatus for cleaning a printing press cylinder according to an embodiment of the present invention. In FIG. 1, a cleaning device 10 is incorporated in a printing press so as to be movable toward and away from a blanket cylinder 12 as a printing press cylinder to be cleaned. That is, the cleaning device 10 has a frame including a main stay 14 having a U-shaped cross section arranged in parallel with the barrel axis of the blanket cylinder 12 and side plates 16 supporting both ends of the main stay 14. The main stay 14 can be moved toward and away from the blanket cylinder 12 by moving the frame back and forth as indicated by an arrow 18 while guiding the side plate 16 by the drive cylinder 20.

A pad base 22 is fixed to a front surface of the mesh stay 14, that is, a surface on the side of the blanket cylinder 12. The pad base 22 is provided with a pressing pad 26 serving as a pressing portion made of an elastic body such as rubber so that the cleaning sheet 24 made of a nonwoven fabric can be brought into press contact with the blanket cylinder 12. is there. Further, between a pair of side plates 16 behind the main stay 14, a supply roll 28 around which the cleaning sheet 24 is wound and a winding roll 30 which winds up the cleaning sheet 24 after wiping the surface of the blanket cylinder 12 are rotatable. It is attached.
The take-up roll 30 is disposed behind the supply roll 28, and when the take-up of the cleaning sheet 24 is started, the cleaning sheet 24 to be taken up as shown in FIG.
And comes in contact with the cleaning sheet 24 wound therearound. When the take-up roll 30 rotates as shown by an arrow 31 and winds up the cleaning sheet 24, the supply roll 28 rotates as shown by an arrow 33 and unwinds the cleaning sheet 24.

A cleaning liquid nozzle 27 for spraying a cleaning liquid onto the cleaning sheet 24 is provided on the upper front surface of the main stay 14. On the other hand, between the main stay 14 and the supply roll 28, a motor 3 serving as a rotation driving means for rotating and driving the take-up roll 30 through a gear train, as will be described in detail later.
2 is arranged. Further, a rotary encoder 34 is provided below the main stay 14 as a winding detection unit for detecting a winding amount (traveling amount) of the cleaning sheet 24. The detection signal of the rotary encoder 34 is input to a controller 36 as a control unit for controlling the driving of the motor 32. Further, an output signal of the counter 38 is input to the controller 36. The counter 38, together with a limit switch 40 disposed near the drive cylinder 20, constitutes a number-of-times detecting means. The counter 38 detects the number of times the cleaning sheet 24 is pressed against the blanket cylinder 12 by the pressing pad 26 and inputs the number of times to the controller 36. .

A gear 44 is attached to a rotating shaft 42 of the motor 32. An intermediate gear 46 meshes with the gear 44 so that a gear 48 or an idle gear 50 attached to the shaft of the supply roll 28 can be rotated via the intermediate gear 46 (see FIG. 2). That is, the intermediate gear 46 is connected to the switching cylinder 47 via a rod, is moved in the axial direction by the switching cylinder 47, and the gear 48 or the idle gear 50
The arrangement position can be changed so as to mesh with one of them. The gear 4 attached to the motor 32
2 has a length that can engage the intermediate gear 46 at any of the two positions where the intermediate gear 46 is disposed.

The gear 48 is attached to the shaft of the supply roll 28 via a one-way clutch (not shown), and rotates the supply roll 28 only in the direction of arrow 33 in FIG. Further, the idle gear 50 is rotatable with respect to the axis of the supply roll 28, and transmits the rotational driving force of the motor 32 to the winding roll 30. That is, a gear 52 is attached to the shaft of the take-up roll 30 via a one-way clutch (not shown), and the gear 52 meshes with the idle gear 50. Therefore, when the intermediate gear 46 meshes with the idle gear 50, the driving force of the motor 32 is transmitted to the gear 52 via the gear 42, the intermediate gear 46, and the idle gear 50, and the gear 52 rotates to rotate. The roll 30 rotates as shown by an arrow 31 in FIG. 1 to wind up the cleaning sheet 24. Brake devices 54 and 56 are attached to the opposite shaft to which the gears of the supply roll 28 and the take-up roll 30 are attached, so that these rolls 28 and 30 can be prevented from running idle. is there.

The rotary encoder 34 has a pair of rotary plates 60 and 62 which are arranged at the axial center of the blanket cylinder 12 and are fixed to a rotary shaft 58. Also,
As shown in FIG. 3A, a plurality of engaging pins 64 are radially attached at equal intervals to the peripheral surfaces of the rotating plates 60 and 62. Then, the rotating plates 60, 62 of the main stay 14
3 (2), a hole is formed as shown in FIG. 3 (2), and an engaging pin 64 provided on the peripheral surface of the rotating plates 60, 62 is formed through this hole. And is pierced by the cleaning sheet 24 and rotated as the cleaning sheet 24 runs.

In the embodiment configured as described above, a series of cleaning operations in the cleaning step are given to the controller 36 as a sequence program.
The winding amount of the cleaning sheet 24 in the cleaning step is given in advance. The winding amount of the cleaning sheet 24 is different depending on the progress of the cleaning in the cleaning process. The winding amount is set to be smaller as the number of times the pressing sheet 26 presses the cleaning sheet 24 onto the blanket cylinder 12 is increased. It is. Further, the set value of the winding amount of the cleaning sheet 24 differs depending on the printed matter. For example, in the case of newspaper printing with many stains, the first two times of cleaning are wound up by about 15 mm, the next two to four times are wound up by about 10 mm, and two to three times are wound up by about 8 mm. After that, it is set so as to wind up by about 5 mm until the cleaning is completed. Also, in the case of commercial printing with little stain on the printed material, wind up the first two rounds of 7 mm each, the next two to three rounds of about 5 mm each, and then wind up about 3 mm until the printing is completed. Is set. The set values of these winding amounts are set in terms of the number of output pulses of the rotary encoder 34. In the embodiment, the intermediate gear 46 is the idle gear 5
0 and the cleaning sheet is wound up by the winding roll 30.

When a cleaning start command is given, the controller 36 supplies the cleaning liquid from the cleaning liquid nozzle 27 to the cleaning sheet 2.
4, the cleaning cylinder 10 is advanced toward the blanket cylinder 12 by driving the drive cylinder 20, and the blanket cylinder 12 is rotated by the pressing pad 26.
The cleaning sheet 24 is pressed. The pressing operation of the cleaning sheet 24 by the pressing pad 26 is performed by the limit switch 40.
Is detected by The detection signal of the limit switch 40 is counted by the counter 38 and sent to the controller 36.

When the cleaning sheet 24 is pressed for a predetermined time, the controller 36 causes the driving cylinder 20 to retreat the cleaning device 10 and, as shown in FIG. Is rotated to wind up the cleaning sheet 24. The winding amount of the cleaning sheet 24 is detected by the rotary encoder 34. That is, the rotary encoder 34
The engaging pins 64 provided on the peripheral surfaces of the cleaning sheets 24 and 62
Cleaning sheet 24 is taken up by winding roll 3
When it is wound around 0 and runs, the rotating plates 60 and 62 rotate, and a detection pulse is input to the controller 36.

The controller 36 reads, from the count value of the counter 38, the number of pulses (winding amount) given corresponding to the number of pressing operations of the cleaning sheet 24 from a memory (not shown), and outputs the pulses output from the encoder 34. The motor 32 is turned off after counting the number read out. For example, when the number of pulses to be counted after the first and second pressing operations of the cleaning sheet 24 is 10, as shown in FIG. 4A, the number of output pulses of the rotary encoder 34 becomes ten. When it reaches, the motor 32 is turned off and the winding operation of the cleaning sheet 24 is stopped. Thereafter, the cleaning device 10 is advanced toward the blanket cylinder 12 in the same manner as described above, and the second cleaning / wiping operation (the pressing operation of the cleaning sheet 24) is started. Then, when the second wiping operation is completed, the motor 32 is driven by 10 pulses of the output pulse of the rotary encoder 34 in the same manner as described above, and the cleaning sheet 24 is wound around the winding roll 30.

In the same manner, the third and fourth times are 8
The cleaning sheet 24 is wound up by the number of pulses, the fifth and sixth times by six pulses, and the fifth and subsequent times by five pulses until the cleaning is completed. When a series of cleaning steps given in this way is completed, the controller 36 supplies a reset signal to the counter 38 to reset the counter.

As described above, in the embodiment, the amount of the cleaning sheet 24 wound up at the beginning of cleaning with a large amount of dirt is increased so that a sufficient cleaning effect can be obtained. Since the winding amount of the cleaning sheet 24 is reduced as the amount decreases, the usage amount of the cleaning sheet 24 can be significantly reduced. For example, in the case of newspaper printing with much dirt, the usage of the cleaning sheet 24 can be reduced by about 45%, and in commercial printing with little dirt, the usage of the cleaning sheet 24 can be reduced by about 30%. Therefore, the cost required for cleaning can be reduced, the interval for replacing the cleaning sheet can be extended, and the printing cost can be reduced.

As shown in FIG. 4B, the drive time of the motor 32, that is, the cleaning sheet 2 is changed by changing the set value of the number of pulses given to the controller 36.
The winding amount of No. 4 can be easily changed. Further, in the above-described embodiment, the case where the pressing of the cleaning sheet 24 is detected by the limit switch 40 has been described. However, the controller 36 counts the number of times such as a given cleaning liquid ejection command or a driving command of the driving cylinder 20. The number of times the cleaning sheet 24 is pressed may be determined based on these count values. Further, in the above-described embodiment, the case where the present invention is applied to cleaning of the blanket cylinder 12 in the offset printing press has been described. However, the present invention can also be applied to cleaning of a plate cylinder and the like of a letterpress printing press.

[0023]

As described above, according to the present invention, since the winding amount of the cleaning sheet is gradually reduced from the initial stage of the cleaning to the final stage of the cleaning, the use efficiency of the cleaning sheet is greatly improved. Can be improved.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a cleaning device for a printing press cylinder according to an embodiment of the present invention.

FIG. 2 is a plan view of the cleaning device according to the embodiment.

FIG. 3 is a detailed explanatory diagram of a rotary encoder according to the embodiment and an explanatory diagram of an arrangement state of the rotary encoder.

FIG. 4 is a diagram illustrating the operation of the cleaning apparatus according to the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Cleaning apparatus 12 Printing machine cylinder (blanket cylinder) 20 Drive cylinder 24 Cleaning sheet 26 Pressing part (press pad) 28 Supply roll 30 Take-up roll 32 Rotary drive means (motor) 34 Take-up detection means (rotary encoder) 36 Control means (Controller) 38, 40 times detection means (counter, limit switch)

Claims (3)

(57) [Claims] 1. A method for cleaning a printing press cylinder in which a cleaning sheet is intermittently wound while being pressed against a rotating printing press cylinder a plurality of times to wipe the surface of the printing press cylinder. Washing the cleaning sheet during each pressing contact operation of the cleaning sheet, and gradually reducing the winding amount of the cleaning sheet from the start of the cleaning to the end of the cleaning. . 2. A cleaning device for a printing press cylinder, comprising: a press unit for intermittently winding a cleaning sheet drawn from a supply roll onto a take-up roll and pressing the cleaning sheet against the press cylinder. Rotation drive means for intermittently rotating the, and winding detection means for detecting the amount of the cleaning sheet wound on the winding roll,
Number detection means for detecting the number of times the cleaning sheet is pressed against the printing press cylinder by the pressing portion, and captures output signals of the number detection means and the winding detection means,
Control means for controlling the winding amount of the cleaning sheet via the rotation driving means, based on a relationship between the number of times the cleaning sheet is pressed against the cylinder of the printing press and the winding amount of the cleaning sheet. A cleaning device for a printing press cylinder, comprising: 3. The relationship between the number of times the cleaning sheet is pressed against the cylinder of the printing press and the winding amount of the cleaning sheet is as follows.
The cleaning device for a printing press cylinder according to claim 2, wherein the winding amount is reduced as the number of times of pressing increases.