JPH04106050A - Correcting device for paper sheet feed timing - Google Patents

Abstract

PURPOSE:To improve quality, such as appearance and precision, during processing, such as printing, to increase working efficiency, and to improve productivity by conveying paper sheets to a subsequent process after unevenness in a sheet feed timing is accurately corrected by means of a correcting device equipped on the downstream side. CONSTITUTION:A delivered paper sheet 3 is conveyed to a downstream timing correcting device K through feed rolls 7a and 7b. An endless belt 20 under running in synchronism with the velocity of periphery of a roll 7 is run at a high speed right before the tip of an input sheet is conveyed to the endless belt. After a fixed claw 19 part is moved ahead in a position where the claw is run in parallel to a sheet pass line, the sheet is brought into contact with the claw 19 part after a reduction receipt 3 is moved thereto to regulate a relative timing to a subsequent process. Consecutively, after the engaging claw is run in synchronism with the velocity of periphery of a feed roll, the engaging claw 19 at the tip of the sheet is moved downward and aside in a way that it is run at a high speed for a given time again. The sheet 3 is consecutively nipped by means of rolls 7, 8, 9, and 10 rotationally driven at a given speed and is conveyed to a printing part P being a subsequent process.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a paper feed timing correcting device configured to correct the paper feed timing in a paperboard conveying section installed in a box making machine for corrugated paperboard sheets, etc. .

(Prior Art) A conventional paper feeding device will be explained based on FIGS. 3 to 5. FIGS. 3 to 5 show the structure of a conventional paper feeding device using a lead edge method and explanations of defects in the device. FIG. 6 is an explanatory diagram of the operation timing of the lead edge feeder. The structure of the conventional paper feeding device will be briefly described below. As shown in FIG. 3, this type of paper feeding device passes corrugated cardboard sheets 3 stacked on a paper feeding table 24 through a gap formed at the lower end of the front guide 1 by rotation of a feed roll 4 provided below the sheet path line. , the lowest layer sheet) 3a, and is configured to be sequentially carried out downstream one by one. A duct 25 is disposed below the corrugated sheet 3 of this device, and a suction box 6 connected to a suction blower 26 via the duct 25 is provided at a position partially below the corrugated sheet 3.

The suction box 6 is in a substantially sealed state by shielding the upper suction surface with the lowermost layer sheet 3a,
A negative pressure region is formed inside by the operation of the suction blower 26, thereby increasing the frictional force F0 between the lowermost sheet 3a and the feed roll 4, which is the conveying means (functioning).

The delivery roll 4 is provided with a receiving plate 5 whose height relative to the outer peripheral surface of the roll 4 can be varied through a hole formed in a portion corresponding to the roll 4. 20 The receiving plate 5 is configured to be able to be raised and lowered, and the lower surface of the lowermost sheet 3a that contacts the delivery roll 4 is attached and removed by raising and lowering the receiving plate 5. By lowering the plate 5, the conveyance force of the feed roll 40 is applied to the sheet 3a, and conversely, by raising the receiving plate 5, the function of conveying the sheet 3a by the feed roll 4 is interrupted. Now, under the above structure, the corrugated paperboard sheet 3 has a frictional force FO1 generated between the bottom layer sheet 3a and the feed roll 4, and the bottom layer sheet 3a.
Frictional force f=F that is generated on the sheet due to the difference in the frictional force F that occurs between the sheet 3b and the second-row sheet 3b.

Under the action of F, the sheet is conveyed between the downstream feed rolls 7a and 7b by this force, and further sent to the downstream printing process P by the rotation of the feed rolls 7a and 7b.

Next, the operation (function) of the conventional paper feeding device described above will be explained. FIG. 6 shows the behavior of the delivery roll 4 and the receiving plate 5 on the vertical axis with respect to the machine (paper feeding) period (horizontal axis). As shown in the figure, the corrugated cardboard sheet 3a comes into contact with the feed roll 4 by lowering the receiving plate 5, and is transferred by the accelerated rotation (peripheral speed) of the feed roll, and the circumferential speed v0 of the downstream feed rolls 7a and 7b increases. Matched point E1
will take over the transfer. At the same time as this handover, the feed roll 4 loses its transfer function due to the rise of the receiving plate 5, and thereafter the feed roll 4 continues to rotate.
It stops at ridge point E2 after one rotation. After one cycle is completed, to convey the next sheet 3b, after lowering the receiving plate 5, the feed roll 4 is rotated again, and the sheet is conveyed as described above.
3b is carried downstream. The setting is such that the stacked corrugated pole sheets 3 are sequentially carried out from the bottom sheet side by repeating the same behavior one after another.

(Problems to be Solved by the Invention) The illustrated conventional paper feeding device has the structure and functions as described above, but has the following problems.

In other words, the feed roll 4 and the sheet 3 are used to carry out the sheet.
Since the structure is such that the rising timing of the receiving plate 5, which intermittents the alignment with the bottom sheet 3a, is always constant (there is no correction function) with respect to the falling timing, the longer the dimensions of the corrugated cardboard sheet 3, the lower the bottom layer sheet 3a. All of the increased frictional force (sliding resistance) F of the second sheet 3b is transferred to the downstream feed roll 7a.
.

The burden must be borne by the clamping rotation of 7b, and for this reason,
A major problem occurred in that the paper feed timing was delayed.

In addition, as shown in Fig. 5, the machine speed and the stacked sheet weight (
Paper feeding misalignment (variations in the amount of misalignment) occurs whenever load conditions such as length, number of stacked sheets), sheet material (friction coefficient), etc. change, which often causes problems in post-processes such as printing. Figure 4 shows the printing start position O from the front edge of the sheet for the above load conditions.
This shows the distance x variation from the standard setting load condition A.
The load increases relative to 0 (A o-+A z )
As the load decreases (A, →A + ), the distance X2 tends to become longer. This tendency occurs because the frictional forces F, F on the upper and lower surfaces of the lowermost sheet 3a change due to changes in load, and the amount of slip between the delivery roll 4 and the lowermost sheet 3a changes. The relative positional relationship between the corrugated pole sheet and the printing plate 22 on the printing cylinder 21 in the printing section P changes, causing the printing position to shift back and forth in the flow direction of the sheet 3. In addition, Fig. 5 specifically shows the above-mentioned tendency, and xl is when the paper feeding timing is delayed with respect to the distance X0 to the ideal printing start position, and X2 is when the paper feeding timing is too early. It shows.

Until now, in order to eliminate such problems, it has been necessary to provide each unit with registration means (device) to correct the deviation in paper feeding timing in the downstream printing process. However, the amount of paper feed misalignment as described above is not constant and often varies from sheet to sheet, so it is not satisfactory to correct it in the printing process, and furthermore, the above-mentioned problem only increases the amount of defective paper generated. This, combined with frequent order changes, caused a significant drop in productivity.

As explained in the prior art section, in conventional paperboard feeding devices, there are large variations in sheet conveyance timing due to fluctuations in the amount of slip between the sheet and the feed roll, which is the means for conveying the same sheet, resulting in poor product quality ( There was a major problem in that the accuracy decreased. That is, the machine speed,
Paper feeding misalignment (significant variation in paper feeding timing) occurs every time load conditions such as sheet weight (sheet stacking height and length) and sheet material change, and paper misalignment occurs each time in downstream processes, such as the printing department. It was necessary to hold a meeting.

The present invention was proposed to solve these problems.

(Means for Solving the Problem) For this reason, the present invention uses a paperboard conveying device installed in a box-making machine for corrugated paperboard sheets, etc., to sequentially transport paperboards stacked on a paper feed table one sheet at a time starting from the lowest sheet. An endless belt having paperboard abutting claws fixed to its outer surface is disposed downstream of the paper feeding device configured as shown in FIG. A means for correcting the paper feeding timing is provided, and the driving speed of the timing correcting means can be arbitrarily controlled variably with respect to the paper feeding speed of the paper feeding device.This is a means for solving the problem. It is something to do.

(Function) According to the present invention, the leading edge of the paperboard that is carried out in a state that varies in the forward and backward directions due to fluctuations in load conditions such as machine speed, stacked sheet weight, sheet material, and sheet length is transferred to the endless belt section. It is possible to brake once with the fixed pawl and then release the pawl at a predetermined timing corresponding to the next printing process to transport the paper. As a result, it is possible to convey the paper downstream with the deviation (variation) in the timing of carrying it out from the paper feeding unit accurately corrected, thereby making it possible to significantly improve processing accuracy such as printing position.

(Embodiment) Below, embodiments of the present invention will be described based on the drawings.
Figures 2 to 2 show an example of a paper feed timing correction device according to the present invention installed in a box making machine for corrugated paperboard sheets.
FIG. 1 is a schematic configuration diagram thereof, and FIG. 2 is an explanatory diagram of its functions. In addition, in FIGS. 1 and 2, a delivery roll 4 sequentially transports the paperboard 3 stacked between the front guide 1 and the backstop 2 one by one starting from the bottom layer, and a drive device (not shown) to a predetermined position. The basic structure of the lead edge type feeder is composed of a receiving plate 5, etc., which intermittents the connection between the lowermost sheet 3a and the outer peripheral surface of the delivery roll 4 by moving up and down at the timing of , and the function of the suction box 60 installed below Since these are the same as those explained in the prior art section, detailed explanation thereof will be omitted here.

The present invention relates to a straightening device configured to straighten the leading edge of a paperboard carried out via a feeder (sheet feeding device) so as to match a predetermined timing, and then convey it to the next process. , functions).

As shown in FIG. 1, one or more sets of feed rolls 8 are disposed in the vicinity of the downstream feed rolls 7a and 7b of the conventional paper feeder WR and are disposed oppositely above and below the sheet path line.
, 9.10 are arranged.

Boo 1J is attached to the shafts of feed rolls 8b and 9b, respectively.
An IL 12 is rotatably attached to the shaft, and a pulley 13 is attached below the feed roll 9. A synchronizer 4 is fixed to a part of the shaft of the pulley 13 which is supported by the shaft. Synchronous pulley 14 and motor 15
A synchro pulley 16 fixed to the shaft end of the synchro pulley 16 is connected to the synchro pulley 16 by a synchro belt 17 wound around both. The motor 15 is, for example, a servo motor or the like, and is configured such that its rotational speed can be arbitrarily set variably at a predetermined timing in response to a command signal from a control device 18 calculated based on the speed of the paper feed motor or the four speeds of the delivery roll. be.

Note that it is desirable that the endless belt speed be operated according to a preset speed diagram (FIG. 2).

By the way, an endless belt 20 is wound around the above-mentioned pulleys 11, 12 and 13, and a pawl 19 is attached to this endless belt 20, which is configured so that the front end of the paperboard comes into contact with it. Although a plurality of belts 20 are arranged in parallel in the width direction of the machine, it is also possible to have one belt located approximately in the center from a functional point of view.

Since the paper feeding timing correcting device gK of the present invention is configured as described above, the corrugated cardboard sheet 3 conveyed from the paper feeding device R has its running timing corrected by this correcting device K, and then the next process printing section After that, as in the conventional type, the printing plate 22 and the impression cylinder 23, which are wound around the printing cylinder 21, are held and rotated to perform printing at the desired position.

Next, the functions will be explained based on FIG.

FIG. 2 is an operation timing diagram, showing the timing of lifting and lowering the receiving plate 5 and the circumference of the delivery roll 4, which is intermittently driven to rotate, with respect to the rotation angle θ (horizontal axis) of the cam drive shaft, which rotates once per cycle of paper feeding operation. Speed ■ and running speed ■ of the endless belt with claws 20 installed in the timing correction device K of the present invention
is shown on the vertical axis. After lowering the receiving plate 5 and bringing the lowermost sheet 3a into contact with the outer peripheral surface of the feed roll 4, the feed roll 4 is rotated at an accelerated rate, and the downstream feed roll 7
The circumferential speed of a and 7b ■. The leading end of the corrugated cardboard sheet 3 carried out in synchronization with the above is held between the feed rolls. Thereafter, the feed roll 4 is rotated at the same speed for a predetermined time determined by the sheet length to assist the sheet travel. As a result, the load acting on the feed roll 7 can be reduced.

Next, after rotating the feed roll by a predetermined angle, that is, after conveying the sheet a predetermined length, the receiving plate 5 is raised to release the conveying action of the feed roll 4, and at the same time, the feed roll 4 is decelerated and stopped. Thereafter, the above-mentioned operations are repeated one after another, and the stacked sheets 3 are fed out one by one starting from the lowest sheet.

Now, the sheet 3 sent out as described above is conveyed to the downstream timing correction device via the feed rolls 7a and 7b. The endless belt 20, which was running in synchronization with the peripheral speed of the feed roll, runs at high speed just before the leading edge of the sheet to be carried in, and as shown in FIG. After that, the sheet 3 is decelerated and the sheet 3 is brought into contact with the pawl 19, and the relative timing with the next process is corrected. Next is the feed roll circumferential speed■. After running in sync with the sheet, the sheet is again rotated at high speed for a predetermined period of time to avoid the claw 19 that is engaged with the leading edge of the sheet downward. The sheet 3 is then held between feed rolls 7, 8, 9 and 10 which are rotated at a predetermined speed, and sent to the next printing section P. Note that the running speed of the endless belt 20 that continues to run is controlled, and its relative position to the cam drive shaft rotation angle is set to match the next operation timing. Thereafter, the above behavior is repeated one after another, and the sheet 3 is conveyed accurately at a predetermined timing corresponding to the downstream process.

The running speed of the endless belt 20 is controlled via a motor 15 driven by a command signal from a control device, and the degree and timing of increase/decrease can be variously combined depending on conditions such as the position of feed rolls. . Furthermore, various types of driving force transmission means, winding methods, etc. of the endless belt can be considered depending on the structure.

These formats are not limited to the above embodiments,
Various changes may be made without departing from the spirit of the invention. In addition, in this embodiment, the drive mechanism of the paper feed timing correcting device was explained using the synchronized belt 17 and the endless belt 20, but it is sufficient that these can be driven with timing, and it is easily possible to replace them with a chain, for example. .

(Effects of the Invention) As described above, according to the present invention, the dispersion in paper feeding timing, which was a problem with conventional paper feeding devices, can be corrected accurately using a downstream correction device, and then the next process can be carried out. Since it can be transported, quality such as appearance and accuracy can be improved during processing such as printing. Furthermore, there is no need to deal with troubles such as printing defects, and the operating rate of the machine is increased, so productivity can be improved. Further, according to the present invention, it becomes possible to deal with paperboard of various specifications, and effects such as expanding the range of production (products) can be expected.

[Brief explanation of drawings]

FIG. 1 is a side view showing a schematic configuration of a paper feed timing correcting device according to the present invention installed in a corrugated sheet box making machine, FIG. 2 is an explanatory diagram of the function (operation timing) of the paper feed section, and FIG.
The figure is a side view of a conventional lead edge type paper feeder.
5 and 5 are explanatory diagrams of paper feeding delays in the conventional paper feeding device, and FIG. 6 is an explanatory diagram of the operation timing of the conventional lead edge feeder. Explanation of the main parts of the figures 1 - Front guide 2 - Backstop 3 - Paperboard (corrugated cardboard sheet) 4 - Delivery roll 5 - Backing plate 6 - Suction box 7a 7b - Feed roll 8a 8b - Feed roll 9a, 9b - Feed roll

Claims (1)

[Claims] In a paperboard conveying device installed in a box-making machine for corrugated cardboard sheets, etc., a paperboard contact is installed on the outer surface downstream of the paper feeding device, which is configured to sequentially transport the paperboard stacked on the paper feeding table one sheet at a time, starting from the lowest sheet. In addition to disposing an endless belt having a connecting claw fixed thereto, a sheet feeding timing correcting means is provided so that the claw is always positioned on a straight line perpendicular to the sheet traveling direction and is driven, and the timing correcting means A paper feeding timing correcting device, characterized in that the drive speed of the paper feeding device can be arbitrarily variably controlled with respect to the paper feeding speed of the paper feeding device.