JP4839265B2 - Cleaning device for sheet conveying belt in sheet-fed printing press - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper discharge unit transport belt cleaning device in a sheet-fed printing machine, and more particularly to a paper discharge unit transport belt cleaning device in a sheet-fed printing machine that removes accumulation of powder for preventing blocking on a transport belt.

  In the paper discharge unit of the sheet-fed printing machine, the sheets that have been printed by the printing unit are transported to a predetermined position by a chain gripper continuously attached to an endless delivery chain and stacked. However, since the printing speed has been improved in recent years, there has been a problem that sheets cannot be stacked well on the paper discharge tray. To solve this problem, a suction wheel equipped with an air suction device and a constantly rotating suction wheel is installed, and the speed of the sheet is reduced when the chain gripper releases the paper while adsorbing the sheet being conveyed. Then, the sheets are aligned by the sheet pad and the sheets are stacked on the sheet discharge table satisfactorily.

However, there is no particular problem if only one side of the sheet is printed, but if it is printed on both sides, the printed side that has not been sufficiently dried may be peeled off or thinned in the transport path. Or there is a risk of contamination due to rubbing.
In order to solve this problem, a paper discharge device that transports a sheet with a chain gripper and discharges the sheet onto a discharge table. The sheet is discharged by a conveyor belt having a plurality of suction holes. It has been reported that the conveyor belt is transported while being supported from below, and the traveling speed of the conveyor belt is reduced when the chain gripper releases the sheet (see Patent Document 1).

As another problem, in the paper discharge unit of the sheet-fed printing press, the printed products are stacked one by one on the paper discharge tray, and the paper is stacked in a stacked state. A printing failure called so-called blocking may occur, in which a compression load is applied depending on the weight of the discharged paper, and the ink of the stacked printed material is transferred to the back surface of the next stacked printed material.
This blocking significantly reduces the value of the printed material and is a major factor in printing complaints. In order to avoid this blocking, conventionally, a method for preventing blocking by spraying an anti-blocking powder on the surface of a printed sheet has been adopted.
However, since the powder sprayed on the printed matter is fine particles, the entire amount of the sprayed powder does not adhere to the printed matter, and there is a problem that most of the powder is scattered around.

The anti-blocking powder scattered around the product may deteriorate the lubrication function by mixing it with the delivery chain, bar, stick, claw, conveyor belt or accessory device, and the lubricating oil in the machine. It is deteriorating.
In particular, the conveyor belt supports and transports the sheet from below, so that the scattered powder tends to accumulate, and it travels a relatively long distance. There is a problem that it is easy to disperse.
In order to solve such a problem, the powder adhering in the paper discharge unit is scattered by a spray nozzle and collected by a suction fan (see Patent Document 2), or the delivery chain is removed with a wire brush when printing is stopped such as during a break. A cleaning method (see Patent Document 3) has been reported.

JP-A-8-192945 JP 2003-320642 A JP-A-7-196220

  However, the method shown in Patent Document 2 is effective for a delivery chain that easily collects the scattered powder because it scatters the adhered powder. However, when it is used for a conveyor belt, it is scattered by an injection nozzle. However, it is easy to deposit again, and there is a problem that sufficient cleaning cannot be performed. Further, the method disclosed in Patent Document 3 has a problem that the conveyance belt is easily damaged and cannot be executed during printing.

(Object of the present invention)
The present invention solves such a problem, and automatically cleans the printing belt without damaging the conveying belt of the sheet-fed printing machine discharge section, and the spray powder is deposited and fixed on the conveying belt. It is an object of the present invention to realize a cleaning device for a paper discharge unit transport belt in a sheet-fed printing machine that prevents a situation in which sheet transport is hindered.

In order to solve the above-mentioned problems, a conveyor belt cleaning apparatus according to the present invention is a conveyor belt cleaning apparatus that supports printed sheets that are held by a chain gripper and conveyed to a sheet discharge table, A cleaning roller that scrapes off the powder for blocking prevention attached to the belt, and a rotation transmission belt that transmits rotation to the cleaning roller from a tension roller that applies tension to the conveyor belt. .
Accordingly, the cleaning force can be used to scrape the powder with the cleaning roller and clean the driving belt without damaging the driving belt.

Here, the cleaning roller is provided with a sheepskin having hair on its surface (Claim 2).
Thereby, it can clean safely and reliably, without damaging a conveyance belt.

Further, the diameter of the tension roller is different from the diameter of the cleaning roller (claim 3).
As a result, a speed difference can be generated between the surface rotation speed of the tension roller, that is, the traveling speed of the conveyor belt and the surface rotation speed of the cleaning roller, and the cleaning roller can rub the conveyor belt due to this speed difference. It can be safely and reliably cleaned without damaging the conveyor belt.

Furthermore, the rotation transmission belt is hung on a tension roller side pulley provided coaxially with the tension roller and a cleaning roller side pulley provided coaxially with the cleaning roller, and compared with a diameter of the tension roller side pulley. The cleaning roller side pulley has a large diameter (Claim 4).
As a result, a speed difference can be generated between the surface rotation speed of the tension roller, that is, the traveling speed of the conveyor belt and the surface rotation speed of the cleaning roller, and the cleaning roller can rub the conveyor belt due to this speed difference. It can be safely and reliably cleaned without damaging the conveyor belt.

Further, the rotation transmission belt is a timing belt, and the pulley on the tension roller side and the pulley on the cleaning roller side are timing pulleys.
Thus, no slip is generated in the rotation transmission belt, the speed difference between the traveling speed of the transport belt and the surface rotation speed of the cleaning roller is maintained, and the cleaning roller can rub the transport belt stably.

A dust collecting device is provided for collecting the anti-blocking powder scraped off by the cleaning roller (Claim 5).
This makes it possible to collect the anti-blocking powder that has been scraped off by the cleaning roller so that it does not scatter around, and increase the suction force because the position of the dust collector is off the sheet transport section. The powder collection efficiency can be increased.

  As described above in detail, according to the conveyor belt cleaning device of the present invention, the anti-blocking powder deposited and adhered to the conveyor belt can be efficiently recovered by scraping without damaging the conveyor belt. .

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a side view showing a configuration of a paper discharge unit of a sheet-fed printing machine in which a cleaning device for a paper discharge unit conveyance belt according to the present invention is used, FIG. 2 is a partially enlarged view showing details thereof, and FIG. FIG. 5 is an assembly plan view of each roller portion including a cleaning device for a paper discharge unit conveyance belt according to the present invention.
1 to 3, the paper discharge unit 1 in the sheet-fed printing machine in which the present invention is used, the printing is completed in the printing unit, and the sheet 2 fed from the intermediate cylinder 12 is hung on the sprocket 5 and rotated. The chain gripper 3 provided on the pair of left and right delivery chains 4 is gripped by a gripping claw and dropped onto the paper discharge tray 20 for loading.
A vacuum box having a predetermined length is provided in the running direction of the sheet 2 upstream of the sheet discharge table 20, and an endless conveyance belt 6 that slides on the upper surface of the vacuum box and rotates in the running direction of the sheet 2 is provided. ing.

The conveyor belt 6 has a suction hole that communicates with the inside of the vacuum box, and the rotation speed thereof is the same as the rotation speed of the printing unit so that the gripping edge and the suction hole of the sheet 2 are matched at the upstream end of the vacuum box. At least the chain gripper 3 separates the sheet 2 and the suction hole of the conveyor belt 6 is removed from the vacuum box, and the sheet 2 is transported while being lowered until it is moved to suction by the suction wheel 11.
The conveyor belt 6 is made of rubber, is rotationally driven by a driving roller 7, is supported by a plurality of conveyor belt feed rollers 18, and travels at the same speed as the chain gripper 3. Even if the printed portion on the lower surface of the sheet is not completely dried, the sheet 2 can be discharged and stacked on the discharge stand 20 without peeling off or rubbing the printed portion.

By the way, in the paper discharge unit 1 of the sheet-fed printing press, the printed materials are stacked one by one on the paper discharge tray 20 and stacked in a stacked state to be sequentially discharged onto the previously stacked paper later. There is a case where a printing failure called so-called blocking occurs, in which a compressive load is applied depending on the weight of the coming paper, and the ink of the stacked printed material is transferred to the back surface of the next stacked printed material.
This blocking significantly reduces the value of the printed material and is a major factor in printing complaints. For this reason, in order to improve inconvenience due to the blocking of the printed matter and the close contact of the paper, a powder spray nozzle spraying device 10 is provided, and from this, the anti-blocking powder is sprayed on the surface of the printed matter in an atomized state and printed. Deposit on the surface of the paper.

The powder for blocking prevention is generally a fine powder of starch or talc, and the particles are generally 70 μm or less, particularly in the range of 10 μm to 30 μm. Blocking is prevented by stacking this on the surface of the sheet. can do.
However, since the anti-blocking powder sprayed on the printed material is fine particles as described above, the total amount of the powder sprayed from the powder spray nozzle does not adhere to the printed material, and about 2/3 is not around. Scatter.

The anti-blocking powder scattered to the periphery adheres to the delivery chain 4, the transport belt 6, or an accessory device, and deteriorates the performance of the printing machine itself.
In particular, since the conveyor belt 6 conveys the sheet 2 while supporting the sheet 2 from below, it is easy to accumulate scattered powder and rotates endlessly over a relatively long distance. Therefore, there is a problem that it is easy to disperse around.
In order to solve this problem, in the present invention, a cleaning device for the paper discharge unit transport belt 6 is provided, and the blocking preventing powder deposited on the transport belt 6 is removed.

The discharge device transport belt cleaning device of the present invention is applied to a tension roller 8, a Mouton roller 9 as a cleaning roller, a pulley 14 on the tension roller 8 side, and a pulley 15 on the Mouton roller 9 side to apply a rotational force. A rotation transmission belt 16 for transmission and a dust collecting device 17 are included.
The tension roller 8 is pressed against the conveyor belt 6 by an elastic means such as a spring to apply tension to the conveyor belt 6 and obtain a rotational force from the conveyor belt 6 driven by the rotation of the driving roller 7. It rotates at the same speed as the running speed.

The rotation of the tension roller 8 is transmitted to the mouton roller side pulley 15 by the rotation transmission belt 16 hung on the tension roller side pulley 14 provided coaxially, and the mouton roller 9 is rotated. At this time, by selecting the diameter of the tension roller 8, the diameter of the tension roller side pulley 14, the diameter of the mouton roller 9, and the diameter of the mouton roller side pulley 15, the rotational speed of the outer periphery of the mouton roller 9 and the traveling speed of the conveyor belt 6 are selected. Set so that a speed difference occurs between For example, the diameter of the mouton roller side pulley 15 is made larger than the diameter of the tension roller side pulley 14 and the rotational speed of the outer periphery of the mouton roller 9 is set to be slower than the traveling speed of the conveyor belt 6.
Here, the rotation transmission belt 16 may be a timing belt, and the tension roller side pulley 14 and the mouton roller side pulley 15 may be timing pulleys. By doing so, the rotation transmission belt 16 is prevented from slipping, the speed difference between the traveling speed of the conveyor belt 6 and the surface rotation speed of the mouton roller 9 is always maintained, and the mouton roller 9 becomes stable. The conveyor belt 6 can be rubbed.

On the outer periphery of the mouton roller 9, sheep skin (mouton) having hair on its surface is stretched.
Further, at the position shown in FIG. 1 and FIG. 2, the surface side of the conveyor belt 6 is in contact with the mouton roller 9.
Therefore, when a difference in speed is generated between the rotational speed of the outer periphery of the mouton roller 9 and the traveling speed of the conveying belt 6 in this way, the loosened portion of the sheepskin on the outer periphery of the mouton roller 9 causes the surface of the conveying belt 6 to move. By rubbing, the powder for blocking prevention adhering to the surface of the conveyor belt 6 is effectively scraped off. Since the outer periphery of the mouton roller 9 is provided with hair loss, the contact with the conveying belt 6 is soft, and even if the conveying belt 6 is rubbed, it will not be damaged.

  A brush 21 for removing the anti-blocking powder adhering to the mouton roller 9 is installed at a position where the brush 21 slightly contacts the hair of the mouton roller 9. The brush 21 can scrape off the anti-blocking powder adhering to the loose hair in accordance with the rotation of the mouton roller 9.

Further, a dust collecting device 17 is provided below the mouton roller 9 and sucks and collects the anti-blocking powder that has been scraped off and suspended by the brush 21 described above. Since the dust collecting device 17 is located away from the printed sheet 2 conveyed by the chain gripper 3, there is little possibility that the sheet 2 is adsorbed or waved by the suction of the dust collecting device 17. The suction force can be increased to a certain extent, whereby the anti-blocking powder can be effectively sucked and collected.
The rotational driving force of the tension roller 8 and the mouton roller 9 constituting the paper discharge unit transport belt cleaning device is based on the rotational force received from the travel of the transport belt 6 by the tension roller 8, so a special drive device needs to be provided. There is no.

  Since the cleaning device for the delivery belt of the present invention is configured and functions as described above, the powder for preventing blocking adhered to the delivery belt 6 may damage the delivery belt 6 during the printing process. The removed powder can be sucked and collected by the dust collector 17.

  Since the present invention can show a remarkable effect on the collection of the anti-blocking powder adhering to the conveying belt in the paper discharge unit of the sheet-fed printing press, it can be widely used in the field of sheet-fed printing in the printing industry. It has a possibility.

FIG. 3 is a side view illustrating a configuration of a paper discharge unit of a sheet-fed printing press in which the paper discharge unit conveyance belt cleaning device of the present invention is used. FIG. 3 is a partial enlarged view of a paper discharge unit shown in FIG. 2. It is an assembly top view of each roller part containing the cleaning apparatus of the discharge part conveyance belt of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Paper discharge part 2 Sheet | seat 3 Chain gripper 4 Delivery chain 5 Sprocket 6 Conveyor belt 7 Drive roller 8 Tension roller 9 Mouton roller 10 Powder spray nozzle spraying device 11 Suction wheel 12 Intermediate body 14 Tension roller side pulley 15 Mouton roller side pulley 16 Rotation Transmission Belt 17 Dust Collector 18 Conveyor Belt Feed Roller 20 Paper Discharge Stand 21 Brush

Claims (6)

A conveyor belt cleaning device that supports a printed sheet that is held by a chain gripper and conveyed to a paper discharge tray,
A cleaning roller that scrapes off the anti-blocking powder adhering to the conveyor belt;
A conveyor belt cleaning device, comprising: a rotation transmission belt that transmits rotation to a cleaning roller from a tension roller that applies tension to the conveyor belt.   The conveyor belt cleaning device according to claim 1, wherein the cleaning roller is provided with a sheepskin having hairs on a surface thereof.   The conveyor belt cleaning device according to claim 1, wherein a diameter of the tension roller and a diameter of the cleaning roller are different.   The rotation transmission belt is hung on a tension roller side pulley provided coaxially with the tension roller and a cleaning roller side pulley provided coaxially with the cleaning roller, and the cleaning roller is compared with a diameter of the tension roller side pulley. 4. The conveyor belt cleaning apparatus according to claim 1, wherein the side pulley has a large diameter.   The conveyor belt cleaning device according to any one of claims 1 to 4, wherein the rotation transmission belt is a timing belt, and the tension roller side pulley and the cleaning roller side pulley are timing pulleys.   The conveyor belt cleaning device according to claim 1, further comprising a dust collector that collects the anti-blocking powder scraped off by the cleaning roller.

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