JP7164427B2 - sheet feeder - Google Patents

Description

The present invention relates to a sheet feeding device used in a printing press that prints on, for example, sheets.

The printing press includes a sheet holding section that holds a sheet group in which a plurality of sheets (sheets, etc.) are stacked. The printing press includes a sheet feeding device that lifts the upper end sheet from the sheet holding group and feeds it toward a feeding target (specifically, a printing section that prints on the sheet).

A conventional sheet feeding device lifts the sheet by air suction. However, for sheets with high air permeability such as Japanese paper, the air to be sucked passes through the gaps because the gaps between the fibers that make up the sheet are wider than those of sheets with low air permeability. , there is a tendency that multiple sheets are supplied. For this reason, there have been cases where reliable lifting cannot be achieved by air suction. In order to solve this problem, there has been a sheet feeding device that uses an adhesive tape to attract the sheet by its adhesive force (see Patent Document 1).

However, in a sheet feeding device using such an adhesive tape, the adhesive of the adhesive tape is transferred to the sheet, which may lead to deterioration in printing quality of the printing machine. Moreover, when the adhesive strength of the adhesive tape becomes weak, it is necessary to replace the adhesive tape, which is troublesome. Thus, there is room for improvement in conventional sheet feeding devices when handling sheets with high air permeability.

JP-A-54-76307

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a sheet feeder capable of feeding even a highly breathable sheet toward an object to be fed without any problem.

A sheet feeding device according to the present invention is a sheet feeding device that lifts an uppermost sheet from a sheet group in which a plurality of sheets are stacked and feeds it toward an object to be fed. a sucker moving unit that performs a feeding operation, and is attached to the sucker moving unit, attracts the upper end sheet by contacting the upper surface of the upper end sheet, and moves the upper end sheet to the sheet group as the sucker moving unit moves. a sucker capable of being lifted upward, wherein the sucker faces the upper surface of the upper sheet and is formed of a soft resin material containing air bubbles; the connecting portion connected to the sucker moving portion; It is characterized by having a part.

In such a sheet feeding device, air bubbles are exposed on the surface facing the upper surface of the sheet in the sheet suction portion. These air bubbles function as minute suckers and can suck the sheet.

Further, the sheet feeding device can lift the upper sheet by sucking air through the sucker moving section, and the area of the surface of the sheet suction section facing the upper surface of the upper sheet is When the air is sucked, the area of the mouthpiece provided at the tip of the sucker moving part can be made larger than that of the mouthpiece.

With this configuration, even the sheet suction portion formed of a soft resin material containing air bubbles can exert a sufficient suction force because the area is larger than that of the mouthpiece.

Further, the sucker may include a soft portion that is softer than the sheet suction portion between the connecting portion and the sheet suction portion.

With this configuration, as the soft portion deforms, the sheet attracting portion can be deformed and brought into close contact with the upper end sheet.

Further, the sucker may include a hard portion that is harder than the sheet suction portion between the connection portion and the soft portion.

With this configuration, the pressing force exerted on the surface of Japanese paper or the like can be relieved while the sheet adsorption portion follows the irregularities of the surface of Japanese paper or the like by compressing and deforming the soft portion by receiving the pressing force of the hard portion.

The sucker moving unit moves downward to cause the sucker to absorb the top sheet, then rises with the sucker sucking the top sheet, and then feeds out the top sheet. The upper end sheet is sent out toward the object to be supplied by swinging the upper end sheet toward the supply object by swinging upward while facing the direction, and the sucker moves the sucker moving portion in the sending direction of the upper end sheet. It can be installed eccentrically so as to protrude greatly toward the front side compared to the rear side.

With this configuration, compared to a shape projecting symmetrically in the front-rear direction, even if the sucker has the same area for sucking the upper end sheet, the amount of downward movement of the sucker during swinging can be reduced.

According to the sheet feeding device of the present invention, the air bubbles exposed on the surface facing the upper surface of the sheet in the sheet adsorption portion can adsorb the sheet. Therefore, even a sheet with high air permeability can be delivered toward the object to be supplied without any problem.

1 is a schematic diagram showing the configuration of a printing press equipped with a sheet feeding device according to an embodiment of the present invention; FIG. 4 is a schematic side view showing a sheet holding portion in the sheet feeding device; FIG. (a) is a schematic side view showing a state in which a sucker lifts the top sheet in the sheet holding portion of the sheet feeding device; (b) is a sheet to be fed, the sucker, the airflow generating portion, and the auxiliary airflow generating; It is a schematic plan view showing the positional relationship with each part. FIG. 3A is a plan view, FIG. 3B is a side view, and FIG. FIG. 5 is a schematic view showing the effect of the sucker in the sheet feeding device being eccentrically attached to the sucker moving portion;

An embodiment of the printing press 1 including the sheet feeding device 23 according to the present invention will be described below with reference to the drawings. As shown in FIG. 1, the printing press 1 of this embodiment is an offset printing press capable of performing multicolor printing on sheets such as sheets. The printing machine 1 includes a paper feeding unit 2 for supplying sheets, a printing unit 3 for printing on one side or both sides of the sheets, and a paper discharge unit 4 for taking out the printed sheets. The paper feeding unit 2 is located on the rear side in the sheet conveying direction (on the upstream side when conveying is taken as a flow) from the printing unit 3 and supplies the sheets to the printing unit 3 . The printing unit 3 has a plurality of printing units 31 arranged side by side in the left-right direction in the drawing in order to perform printing of each color. The number of printing units 31 can be set as appropriate. Note that a surface treatment section that performs surface treatment on the printed sheet may be provided between the printing section 3 and the paper discharge section 4 .

The paper feeding section 2 includes a feeder board 21 , a sheet holding section 22 and a sheet feeding device 23 . The feeder board 21 makes the sheet stand by at the rear side of the printing section 3 in the transport direction (the front side entering the printing section 3) in order to feed the sheet to the printing section 3 sheet by sheet. The sheet holding unit 22 is provided on the rear side in the sheet conveying direction of the feeder board 21 and holds a sheet group P in which a plurality of sheets are vertically stacked. The sheet group P is stacked on a sheet feeding table 221 that moves up and down.

The sheet supply device 23 is a device that lifts the uppermost sheet S in the stacked state from the sheet group P arranged in the sheet holding portion 22 and feeds it toward the feeder board 21 that is the object to be supplied. The sheet feeding device 23 has a sucker moving section 231 and a sucker 232 . The sheet feeding device 23 is provided with a plurality of sets (four sets in the present embodiment) of the sucker moving portion 231 and the sucker 232 . It should be noted that although it is called a "sucker" because it has the same function as the conventional one, the sucker 232 of the present embodiment does not have a configuration for sucking air like the conventional one.

The sucker moving part 231 has, for example, a bar shape or a frame shape, and moves up and down to send out the upper end sheet S. As shown in FIG. More specifically, as indicated by the arrows in FIG. 2, by swinging along a downwardly curved track in the vertical direction and in the direction from the rear (upstream direction) to the front (downstream direction) in the conveying direction. , the part that produces the forward force. The force thus generated serves as a force for sending the upper end sheet S forward.

The sucker 232 is detachably attached to the tip (specifically, the lower end) of the sucker moving portion 231 . The sucker 232 is provided so as to contact the upper surface of the top sheet S in the sheet group P. As shown in FIG. As the sucker moving portion 231 moves, the sucker 232 can lift the top sheet S above the sheet group P. As shown in FIG.

The sucker 232 has a connection portion 2321 , a base portion 2322 , a sheet adsorption portion 2323 and an intermediate portion 2324 . The base portion 2322, the sheet adsorption portion 2323, and the intermediate portion 2324 are layered and laminated as shown in FIG. 4B. The connecting portion 2321 is a portion connected to the tip portion of the soccer moving portion 231 . The connecting portion 2321 is made of resin, and is connected by being fitted to the tip portion of the tubular sucker moving portion 231, for example. The base portion 2322 is positioned below the connection portion 2321 and is made of a hard resin plate in this embodiment. This base portion 2322 is provided for shape retention of the upper portion of the soccer 232 . The base portion 2322, the sheet adsorption portion 2323, and the intermediate portion 2324 are each formed in layers, and are laminated and integrated.

The sheet adsorption portion 2323 is provided on the entire surface of the sucker 232 in a portion facing the upper surface of the upper end sheet S. As shown in FIG. The sheet adsorption portion 2323 is made of a soft resin material containing air bubbles. More specifically, by foaming, as shown in FIG. It is formed from a soft resin material that contains In this embodiment, the sheet adsorption portion 2323 is made of urethane resin. However, the material is not limited to this. A large number of recessed holes 2326 are formed by exposing the air bubbles 2325 on the lower surface of the sheet suction portion 2323 that faces the upper surface of the sheet. The recessed hole 2326 functions as a minute sucker to suck the sheet. Specifically, the volume of the space in each of the minute suction cups is reduced by deformation of the soft resin surrounding the space as the sucker 232 is pressed against the upper end sheet S, and in this state, the surface of the upper end sheet S is reduced. Adsorption force is generated by abutting against (microscopically, the outer surface of the fibers forming the upper end sheet S). Due to this adsorption force, the sucker 232 can hold the top sheet S lifted above the sheet group P as the sucker moving portion 231 moves.

Since the recessed holes 2326 function as minute suction cups, the gaps between the fibers constituting the sheet are wider than those of the sheet with low air permeability, so that the sheet (such as Japanese paper) has high air permeability in the thickness direction. Also, since a large number of recessed holes 2326 can absorb the fibers themselves, it is possible to more reliably absorb the fibers than in the conventional structure in which air is sucked. Note that the adsorption between the sheet adsorption portion 2323 and the upper end sheet S occurs as the forward force in the conveying direction acting on the upper end sheet S as it is fed to the feeder board 21 becomes larger than the adsorption force of the sheet adsorption portion 2323 . It is released naturally, and the upper end sheet S moves away from the sheet adsorption portion 2323 . For this reason, in the present embodiment, as in the conventional configuration for performing air suction, measures for weakening the suction force, such as stopping or weakening the air suction to separate the upper end sheet S from the sucker 232, and blowing air, are provided. No active action is required.

In this embodiment, the intermediate portion 2324 is formed of two layers, a soft portion 2327 near the sheet suction portion 2323 (lower layer) and a hard portion 2328 near the connecting portion 2321 (upper layer). It is said that The soft portion 2327 is softer than the sheet adsorption portion 2323 , and the hard portion 2328 is harder than the sheet adsorption portion 2323 . In this embodiment, sponge is used for the soft portion 2327 and plate rubber is used for the hard portion 2328 . When the sheet is made of Japanese paper or the like having an uneven surface, the soft portion 2327 deforms the sheet adsorption portion 2323 to bring the sheet into close contact with the top sheet S as the soft portion 2327 deforms. Further, the hard portion 2328 supports the pressing force of the sheet adsorption portion 2323 to the upper end sheet S from above, so that the sheet adsorption portion 2323 can be brought into close contact with the upper end sheet S reliably. Further, the soft portion 2327 is compressed and deformed by the pressing force of the hard portion 2328 by the intermediate portion 2324 in which the soft portion 2327 and the hard portion 2328 are combined. The pressing force acting on the surface can be relaxed while keeping the following state. That is, a moderate pressing force can be generated. Therefore, it is possible to prevent some of the fibers forming the Japanese paper or the like from peeling off and adhering to the sheet adsorption portion 2323 due to excessive pressure.

The sucker 232 of this embodiment can also be used in the conventional sheet feeding device 23 capable of lifting the top sheet S by air suction via the sucker moving portion 231 . Note that when the sucker 232 of this embodiment is replaced, the originally provided mechanism for sucking air is not used. When used in this manner, the area of the surface of the sheet attracting portion 2323 facing the upper surface of the upper end sheet S (the lower surface of the sheet attracting portion 2323) is provided at the tip of the sucker moving portion 231 when air is sucked. It is larger than the area of the surface facing the upper surface of the top sheet S in the mouthpiece (not shown). By setting the area in this manner, even the sheet suction portion 2323 made of a soft resin material containing air bubbles can exhibit a sufficient suction force due to the large area.

The sucker 232 protrudes farther forward than backward relative to the sucker moving portion 231 in the feeding direction of the top sheet S (in this embodiment, the horizontal direction toward the feeder board 21 (leftward direction in FIG. 1)). (See FIGS. 3(a) and 3(b) and FIGS. 4(a) and 4(b)).

Here, the sucker moving part 231 moves downward to cause the sucker 232 to hold the top sheet S, then rises while the top sheet S is held by the sucker 232, and then bends as shown in FIG. As indicated by the arrow, the upper end sheet S is sent out toward the object to be supplied by swinging in such a manner that the upper end sheet S is lowered once in the feeding direction and then raised.

Due to the eccentric attachment of the sucker 232, the corner 232a behind the sucker 232 in the conveying direction from the connecting portion 2321 is larger than the shape of the sucker 232 projecting forward and backward symmetrically (the shape of the sucker 232X for comparison shown on the left side of FIG. 5). (lower right corner shown in FIG. 5) can be reduced, even if the area of the sucker 232 holding the upper end sheet S is the same, the amount of downward movement during rocking is shown in FIG. can be made smaller by the distance H. Therefore, the sucker 232 is less likely to interfere with the sheet group P, so damage to the sucker 232 and the top sheet S can be suppressed.

Next, in the present embodiment, as shown in FIGS. 2 and 3A and 3B, an airflow generating section 233 is provided behind the sheet group P in the sheet holding section 22 in the conveying direction. A nozzle or a blower, for example, can be used as the airflow generator 233 . The airflow generating portion 233 generates an airflow along the feed-out direction of the upper-end sheet S between the upper-end sheet S and the remaining sheet group P when the sucker 232 lifts the upper-end sheet S. Specifically, after the sucker 232 lifts the top sheet S, the airflow is generated.

The airflow generating section 233 generates an airflow between the upper end sheet S and the remaining sheet group P in the sending direction of the upper end sheet S, thereby assisting the lifting of the upper end sheet S from the remaining sheet group P. . Further, even if the lifting force of the upper end sheet S by the sucker 232 is weak, the upper end sheet S can be reliably sent forward in the conveying direction by being placed on the air current.

The airflow generating part 233 needs to be provided between the position of the lower surface of the top sheet S and the position of the upper end of the remaining sheet group P. As shown in FIG. For this reason, the airflow generating section 233 is provided so as to move up and down so as to follow the upper end position of the sheet group P, for example, by interlocking with the paper feed table 221 .

The airflow generated by the airflow generating section 233 is weaker than the airflow that is sent to the upper portion of the sheet group P in the conventional sheet feeding device 23 to separate a plurality of sheets. . Further, the airflow generating section 233 operates only after the sucker 232 lifts the top sheet S and until the delivery of the top sheet S is completed. As a result, it is possible to prevent the upper end sheet S from fluttering due to the airflow hitting a highly breathable sheet such as Japanese paper, which is relatively difficult to be lifted by the sucker 232, and as a result, hindering the lifting. .

In the present embodiment, as shown in FIG. 3B, an auxiliary airflow generating section 234 is provided in the sheet holding section 22 toward the front of the sheet group P in the conveying direction (indicated by a thick arrow). A pair is provided facing each other in a direction perpendicular to the conveying direction. The auxiliary airflow generator 234 generates an airflow that is orthogonal to the sheet conveying direction and sandwiches the sheet group P. As shown in FIG. The auxiliary airflow generating section 234 allows the upper end sheet S sent out by the sucker moving section 231 and the sucker 232 to be sent to the feeder board 21 without shaking in the direction perpendicular to the conveying direction. The strength of the airflow generated by the auxiliary airflow generating section 234 may be sufficient as long as the upper end sheet S is suppressed from shaking.

The sheet feeding device 23 and the sheet feeding method according to the present invention are not limited to the above embodiments, and various modifications are possible without departing from the gist of the present invention.

For example, the movement of the soccer moving part 231 does not necessarily require rocking. The sucker 232 moves up and down so as to come into contact with the upper surface of the upper end sheet S, and moves forward in the conveying direction so as to apply force to the upper end sheet S while holding the upper end sheet S. , the moving route of the soccer moving unit 231 is not particularly limited.

REFERENCE SIGNS LIST 1 printing machine 2 paper feeding section 3 printing section 4 paper discharging section 21 feeder board 22 sheet holding section 23 sheet feeding device 31 printing unit 221 paper feeding table 231... sucker moving part 232... sucker 233... air current generating part 234... auxiliary air current generating part 2321... connection part 2322... base part 2323... sheet adsorption part 2324... intermediate part 2325... bubble 2326... depression Hole 2327 Soft portion 2328 Hard portion P Sheet group S Top sheet H Difference in amount of downward movement (distance) during rocking

Claims (4)

A sheet feeding device that lifts the uppermost sheet from a sheet group in which a plurality of sheets are stacked and feeds it toward an object to be fed,
a sucker moving unit that moves up and down to send out the upper end sheet;
a sucker attached to the sucker moving part, capable of sucking the top sheet by coming into contact with the upper surface of the top sheet, and lifting the top sheet above the sheet group as the sucker moving part moves; has
The sucker has a connection portion connected to the sucker moving portion, and a sheet adsorption portion facing the upper surface of the top sheet and formed of a soft resin material containing air bubbles. On the lower surface, which is the surface facing the upper surface of, a large number of depression holes are formed by exposing the bubbles, and these depression holes function as minute suction cups,
The sheet feeding device , wherein the sucker includes a soft portion that is softer than the sheet attracting portion between the connecting portion and the sheet attracting portion . the sheet feeding device is capable of lifting the top sheet by air suction via the sucker moving section;
wherein the area of the surface of the sheet suction portion facing the upper surface of the upper sheet is larger than the area of the mouthpiece provided at the tip of the sucker moving portion when the air is sucked; The sheet feeding device according to claim 1. 2. The sheet feeding apparatus according to claim 1 , wherein said sucker has a hard portion harder than said sheet attracting portion between said connection portion and said soft portion. The sucker moving unit causes the sucker to adsorb the top sheet by moving downward, then rises with the top sheet adsorbed to the sucker, and then moves in the feed-out direction of the top sheet. the upper end sheet is sent out toward the object to be supplied by swinging the upper end sheet so as to move downward and then upward while facing the object;
4. The sucker according to any one of claims 1 to 3 , wherein the sucker is eccentrically attached to the sucker moving part so as to protrude farther forward than backward in the feed-out direction of the upper end sheet. The sheet feeding device according to .

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