JPS58152733A - Device for sucking sheet of paper by air - Google Patents

Abstract

PURPOSE:To surely suck and separate a sheet of paper, by turning a sheet sucking section after its sucking action and by gradually accelerating the turning. CONSTITUTION:In a device for sucking a sheet of paper by air, the uppermost 39' of plural sheets of paper 39 set on a paper feed rest 40 is sucked up by a sucking force caused in a sucking section 5, so that the uppermost sheet is delivered to a sheet conveyor 41 comprising pinch-holding members. The sucking force is regulated by a sucking force control circuit 63. The sucking section 5 can be turned in the direction of an arrow E about a fulcrum on the point of contact of a pressure roller 16 with the sheet 39' when it is sucked. When the suction of the sheet 39' by the section 5 is found out by a detection circuit 62, a motor not shown in the drawing is regulated by a speed control circuit 61 to gradually accelerate the upward turning of the sucking section 5 in the direction of the arrow E.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for feeding sheet-like paper, and in particular to a device for feeding sheet-like paper one by one, particularly in copying machines, electronic files, facsimile machines, printing machines, etc. The present invention relates to an air suction type sheet paper adsorption device that sucks air into sheet paper to be used for processing.

Conventionally, a device that feeds sheets of paper or originals, etc. stacked on a paper feed table one by one to a predetermined position, has a paper feed roller that faces the stacked sheets of paper. It is common to feed paper one sheet at a time by rotating a paper roller, and it is widely used. A device using this paper feed roller feeds a sheet of paper by utilizing the friction of the roller. Therefore, it easily damages the sheet paper (manuscript), stains the surface of the sheet paper, easily causes slippage on art paper or coated paper with a low surface friction coefficient, and friction caused by paper dust and changes in the roller material over time. This method has many drawbacks, such as the tendency to cause paper feeding errors due to a decrease in coefficients.

Therefore, in order to solve these drawbacks, various devices have been proposed that use air suction to adsorb sheet paper and convey this suction paper.

A device that uses this air suction has an air suction [
] is connected to a suction air casing equipped with a negative filter inside, and the uppermost sheet of multiple sheets stacked on the paper feed table is transferred to the bottom surface of the sheet paper suction unit. The structure is such that the suctioned sheet paper is transported. However, in the above-mentioned sheet paper suction device, the position of the sheet paper suction part during suction is fixed, so the suction of the sheet paper suction part
'' and the top sheet of paper must be made uniform over the entire area, or suction failure will occur. In other words, if a part of the suction part is in contact with the sheet paper and a gap is created in the other part, the suction force (
(Negative pressure) decreases significantly, making it impossible to adsorb the sheet.

Therefore, the suction port of the sheet paper suction unit must be placed with high accuracy with respect to the sheet paper, and the adjustment thereof becomes extremely troublesome.

Furthermore, if the surface of the uppermost sheet of paper is uneven, the suction port and the paper inevitably do not come into close contact with each other and a gap is created, and air flows in through this gap, resulting in poor suction (suction error).

In addition, in the past, if there were multiple sheets of paper or originals that were attracted, it was necessary to separate the second sheet of paper from the paper that was being fed. When separating, it is often the case that the suction paper (the paper to be fed) is also pulled away from the sheet suction unit at the same time. In other words, in the conventional air suction type sheet paper suction device, the suction paper is not reliably separated from the next and subsequent sheets.

SUMMARY OF THE INVENTION In view of the above-mentioned drawbacks, the present invention provides a sheet suction device that can perform reliable suction without causing suction failure, and can effectively separate sheets. Further, the present invention provides an apparatus that can perform a suction operation reliably even if the interval between the sheet paper suction unit and the sheet paper is not precisely arranged.

The present invention is characterized in that when a plurality of sheets are suctioned, the sheet suction section is rotated and the rotating speed is gradually increased in order to separate the next and subsequent sheets. In other words, by rotating the sheet paper adsorption section, air flows between the first sheet of paper and the next sheet of paper, making it easy to separate the sheet paper that is adsorbed to the first sheet of paper. become.

In the present invention, when the sheet paper suction section is rotated, a pressure roller is provided to press the upper part of the sheet paper, and the paper suction section is rotated using this pressure roller as a fulcrum.

Furthermore, the present invention connects the sheet paper suction section to the negative pressure chamber through a flexible duct, so that the suction section has a degree of confidence, and even if the distance between the sheet paper suction section and the sheet paper is not uniform,
This enables reliable adsorption. DESCRIPTION OF THE PREFERRED EMBODIMENTS An air suction type sheet paper suction device will be described below with reference to the drawings showing an embodiment of the present invention.

1 and 2 are side sectional views showing the air suction type sheet paper suction device according to the present invention, the third section is a rear view showing almost the entire sheet paper suction device, and FIG. A bottom view showing -K of the suction port, FIG. 5 is an explanatory diagram for explaining the operation of the present invention, and FIG. 6 is a circuit diagram for repeating the suction operation of the present invention. As shown in Figures 1 and 2, 1 in the figure is a suction air casing (hereinafter referred to as the air suction box) which is equipped with a negative pressure chamber 2 inside. For example, a plurality of air suction ports 6 are installed on the bottom surface through a flexible duct (hereinafter referred to as duct) 3 made of cloth-filled rubberized cloth.
A sheet paper suction unit 5 having a sheet paper suction unit 5 is connected. Duct 3
The respective end portions are fixed to the inner surface of the air suction box body 1 and the inner surface of the side plate 5-1 of the sheet paper suction section 5 by fixing members 4, respectively. The duct 3 may be formed into a bellows shape so that it can be deformed as shown in the figure, but it may also be formed from a member that is expandable and contractible so that its length can be changed.

The sheet paper suction unit 5 is constantly pulled with a downward force by a tension member 8 such as a spring. The tension member 8 has one end fixed to the upper part of the U-shaped tension angle 9, and the other end fixed to the lower part of the U-shaped square stopper angle 7.

The tension angle 9 is fixed to a side plate 5- forming the sheet suction section 5, and the stopper angle 7 has an upper portion fixed to the air suction box 1. The other tension member 8 has one end fixed to a slider 15 that is slidably provided on the slide shaft 14, and a slider 15 that restricts the sliding of the slider 15 to the lower limit.
The other end is fixed. In other words, both tension members 8
Due to the biasing force, the lower piece of the U-shaped tension angle 9 is constantly pulled downward from the sheet paper suction unit 5 to the position where the lower piece of the stopper angle 7 contacts the slider 15 and the slider stopper lO. (See the solid line diagram in Figure 1). Note that one end of the slide shaft 14 is fixed to one side plate of the upper air suction box body 1.

The slider 15 also has a rotation angle 1 which is rotatably mounted on the rotation shaft 12 via a bearing 11 in the direction of the arrow.
3 is pivotally supported, and the rotation angle 13 is connected to the side plate 5 of the sheet paper suction section 5.

Fixed. Therefore, since the duct 3 can be deformed as shown by the broken line, the sheet paper suction section 5 is
It has a degree of freedom in which it can move up and down in the direction of arrow B within the length range of interval l shown along line 4. Further, the sheet paper suction unit 5 is rotated in the direction A within a range l around the rotation axis 12.

Next, referring to FIG. 2, the configuration of the pressure roller for pressing the top sheet of paper will be described.

In the figure, 16 is a pressure roller. This pressure roller 16 is
It is rotatably provided via a bearing 17 around a shaft 18 supported by an angle 43. The angle 43 is a bearing member 2 provided at the rear of the air suction box body 1.
The slider 21 is fixed to the end of a vertically movable slider 21 that passes through the hole. An engagement piece 21a is provided at the upper end of the slider 21, with which one end of an arm 22 attached to the rotating shaft 28 engages. Further, one end of the angle 23 attached to the rotating shaft 28 is engaged with a latch 26 connected to the solenoids 2 to 5. The on/off operation of the solenoid 25 causes the slider 21 to move up and down within a range of the interval 1 via the latch 26. When the solenoid 25 is off, the pressure roller 16 is I! can only move upwards. With the above-described configuration, the pressure roller 16 can be moved up and down by the distance l by the solenoid 25.

Further, in FIG. 3, reference numeral 33 is a motor for driving, particularly rotating, the entire sheet paper suction device. This motor 33 is attached to a motor mounting angle 37.

Reference numeral 29 is a plywood board directly connected to the air suction box l, and a support member 30 integral with the drive shaft 36 is provided at the bottom of this base plate 29.
is attached. The drive shaft 36 passes through a bearing part of a bearing (not shown) provided on the support member 31 and fixed to the upper part of the motor mounting angle 37.

Further, the rotational force from the motor 33 is transmitted to the drive shaft 36 through engagement between a worm 34 provided on the rotation shaft of the motor 33 and a worm wheel 35 fixed to the drive shaft 36 . Note that the reference numeral 32 indicates a replaceable duct that connects the suction blower (not shown) and the air suction box.

When the motor 33 is rotated, the drive shaft 36 rotates, so the support member 30 directly connected to the shaft 86 rotates, and the air suction box l to which the base plate 29 is fixed is rotated. . Therefore, the sheet paper suction section 5 is similarly rotated.

At this time, with the pressure roller 16 in contact with the sheet paper P, the sheet paper suction section 5 is rotated about the pressure roller 16 as a fulcrum. The above motor 33
Speed control is performed by a speed control circuit 61 shown in FIG. The rotation of the speed controller is gradually accelerated and driven, and when the sheet paper suction unit 5 reaches the position shown in FIG. 5(b), a signal R from a detection means (not shown) to detect this The rotation of the motor 33 is stopped. Sheet paper adsorption detection circuit 6, which will be explained further later
If the sheet paper to be sucked is not detected in step 2, the speed control circuit 61 reverses the motor 33 based on this signal, returns the sheet paper suction unit 5 to its original position,
Repeat the suction operation.

Next, in FIG. 4, the sheet paper suction unit 5 is sucked
I will explain about it. As shown in the figure, the suction port 6 consists of two large suction ports 6a facing each other near the edge of the paper size on the bottom surface of the sheet paper suction unit 5, and a number of small suction ports 6b between them. . Further, a large number of small suction ports 6c are provided on the left side of the large suction port 6a. This small suction port 6c is provided to suction not only B5 or B4 size sheets but also A4 or A3 size sheets without sag. still,
83 or B4 corresponds to the lateral direction, and B5 or A4 corresponds to the longitudinal direction.

- The suction force of the suction port 6 for sucking air is controlled by a suction force control circuit 63 shown in FIG. The suction force control circuit 63 controls the rotation of a suction blower, etc.
The suction force is controlled, and air suction is performed via the suction port 6 based on a suction command. Further, when a sheet paper non-detection signal is input from the sheet paper adsorption detection circuit 62,
Outputs a signal for repeating the suction process to perform the suction operation again. At this time, the suction force control circuit 63 counts the non-detection signal using, for example, a counter or the like, and when the counted value reaches a certain number, the suction force is strengthened and the suction operation is repeated.

The operation of the device constructed as described above will be explained below with reference to FIGS. 5 and 6.

First, in FIG. 5, reference numeral 39 indicates a large number of sheets stacked on the upper part of a paper feed table 40 which is provided to be movable up and down in the direction of arrow C, and 42 indicates a guide plate for the sheets being conveyed. , 41 indicates a sheet conveying device in a standby state. In this device, a mode is set to change the suction force depending on whether the sheet to be conveyed is thin or thick. If the sheet of paper is thin, the suction force is set so that it does not strongly suck many sheets of paper, and if the sheet of paper is thick, the suction force is set to a value that can attract the sheet of paper. In other words, the suction force control circuit 63 shown in FIG. 6 controls and drives a suction blower to reduce the suction force for thin sheets of paper, for example, compared to the case of thick paper, depending on the mode setting. As a result, the suction force is weakened and the sheet paper suction unit 5 performs a suction operation for thin paper.

Now, in FIG. 5(a), when a signal instructing the start of feeding of sheet paper is output, the paper feed table 40 moves the uppermost sheet paper 39' of the sheet paper 39 stacked thereon. It rises in the direction of arrow C to a position where the bottom surface of the sheet paper suction section 5 and the pressure roller 16 are pushed up to some extent. In this state, air is sucked from a plurality of air suction ports 6 provided on the bottom surface of the sheet paper suction section 5. That is,
A suction blower (not shown) is driven by the suction force control circuit 63 to start suctioning the sheet paper. At this time, even if the stop position of the paper feed table 40 is different from the normal position, that is, the distance between the sheet paper and the suction port 6 is uneven,
The above error is corrected (absorbed) by the action of the duct 3.

This is because, as explained in FIG. 1, the duct 3 allows the sheet paper suction unit 5 to move up and down by a maximum length l with respect to the air suction box 1, and also to rotate within that range. Therefore, if the length error is less than the above l, the uppermost sheet paper 39' will surely come into close contact with the suction port 6.

In addition, due to environmental conditions, changes, wrinkles, etc.
Even if the paper surface becomes uneven, the suction port 6 and sheet paper 3
The density with 9 is ensured. Therefore, the suction operation of the sheet paper is reliably performed by starting the air suction operation by the suction blower, and it is possible to prevent a decrease in the suction force due to the inflow of air suction that occurs when the adhesion is insufficient. In this state, the sheet paper 39 is under pressure by the pressure roller 16. Here, the suction force control circuit 63 performs a suction operation with a suction force according to the mode of the paper being used.

When the sheet paper 39 is attracted as described above, the operation shown in FIG. 5(b) is subsequently performed. This operation consists of rotating the entire device in the direction of arrow E from the state shown in FIG. 5(a). This rotation is performed by pressing the pressure roller 1 while maintaining the suction operation.
This is done by driving the motor 33 (see FIG. 3) using the point of contact between the lower part of the paper 6 and the uppermost sheet 39 as a fulcrum.

In this case, the speed control circuit 61 gradually accelerates and drives the motor 33 to rotate, thereby increasing the rotation of the sheet paper suction unit 5 while gradually accelerating it. The sheet paper suction section 5 is detected by a position detection means (not shown) when it reaches a predetermined position, that is, a sheet paper transport position. Based on this detection signal, the speed control circuit 61 stops the rotation of the motor 33 and holds the sheet suction section 5 at the position shown in FIG. 5(b).

By gradually increasing the acceleration and then increasing the rotation in this manner, air can easily flow between the uppermost sheet 39' and the next sheet, and the two can be easily separated. In addition, in order to gradually accelerate and raise the sheet paper suction unit 5, the sheet paper 39' being sucked into the suction port 6 is
This prevents air from flowing into the gap between the two and prevents suction errors due to a decrease in suction power. In other words, if the sheet paper 39' that is being sucked is suddenly pulled up, a large force acts on the sheet paper 39' to move it away from the suction port 6, making it difficult for air to flow in and causing frequent suction errors. This is controlled by the speed control circuit 61.
This can be prevented by configuring the sheet paper suction unit 5 to be gradually accelerated.

Next, in the state shown in FIG. 5(b), if the top sheet paper 39
' is not attracted to the suction port 6 of the sheet suction unit 5, the sheet suction detection circuit shown in FIG. 6 detects this. This sheet paper suction detection circuit 62 detects the presence or absence of suction, and repeats the above-described suction operation based on this detection. Further, the circuit 62 detects, for example, a change in the load current of a suction blower, and thereby determines whether the sheet paper 39 is attracted to the suction port 6 or not. for example,
When the load current of the suction blower becomes large, it is detected that the sheet paper is attracted to the suction section 5. Instead of such detection, a microswitch or optical detection means may be provided in the sheet suction section 5 to detect whether or not a sheet is suctioned. Therefore, if the sheet paper suction detection circuit 62 does not detect sheet paper suction in the state shown in FIG. 5(b), the same suction operation as described above is performed. That is, the non-detection signal from the suction detection circuit 62 is applied to the speed control circuit 61, and the circuit 61 reverses the motor 33 to return to the state shown in FIG. 5(a).

Then, the suction operation by the suction force control circuit 63 is repeated. If the sheet paper 39 cannot be attracted even after repeating this suction operation a plurality of times, the suction detection circuit 62 outputs a signal to that effect to the suction force control circuit 63. The suction force control circuit 63 receives the above-mentioned signal and outputs an instruction signal for further increasing the suction force and repeating the suction operation. The suction operation is repeated several times with this suction force strengthened, and if suction is still not achieved, the entire operation is immediately stopped. At the same time, an alarm circuit (not shown) is activated to notify that the device is not attracted.

Further, in the state shown in FIG. 5(b), the pressure roller 16 moves slightly in the direction of arrow G, but presses the sheet paper 39 with a constant pressure. Therefore, when a plurality of sheets of paper are attracted, the stiffness of the paper becomes stronger due to the effect of the pressure applied by the pressure roller 1G. Therefore, the pressing force of the pressure roller 16 or the suction force between the sheets is overcome, and the sheets next to the suctioned sheet are caused to fall. The fallen sheet returns to its original position (normal position) without shifting due to the pressure effect of the pressure roller 16.

On the other hand, if the suctioned sheet falls for some reason after the uppermost sheet 39' has been properly suctioned as described above, the sheet suction detection circuit detects the fall. As a result, Figure 5(a) again,
Repeat operation (b).

In the sheet paper suction section 5, the sheet paper is sucked by the air suction port 6, but from the shape of the air suction port shown in FIG.
1).

Therefore, the center portion of the sucked sheet does not sag. In FIG. 4, if the size of the sheet paper is A4 or 83, the - side edge will be out of the large suction port 6a, but since the small suction port 6c is provided in that part, one side of the sheet paper The ends are also stably adsorbed without sagging. In addition, in the case of B5 or B4 size sheet paper, if the paper does not face the small suction port 6c and there is a risk that the sucked sheet paper may fall due to a decrease in suction force, for example, a shutter mechanism may be provided. , the small suction port 6c may be shielded.

When the uppermost sheet paper 39 is suctioned as described above, the leading edge of the uppermost sheet paper 39 is then transferred to the sheet paper conveying device 41.
5 (c), and begins to be conveyed in the direction of arrow H. When carrying out this conveyance, the suction operation and the pressure applied by the pressure roller 16 hinder the conveyance. Therefore,
At the same time as the suction operation is stopped, the pressure roller 16 is pulled up in the G direction by driving the solenoid 25 (
(See Figure 2). As a result, the sheet paper can be transported smoothly without being damaged under any load.

By repeating the above operations shown in FIGS. 5(a), 5(b), and 5(c), one stacked sheet of paper can be sequentially conveyed. By repeating such conveyance, the surface of the uppermost sheet paper gradually decreases. However, even if the surface of the sheet paper is lowered, the action of the flexible duct 3 ensures that the sheet paper is in close contact with the bottom surface of the sheet paper suction section 5.

As described above, according to the sheet paper suction device of the present invention, the sheet paper suction unit is rotated after the suction operation and this rotation is gradually accelerated, so that the uppermost sheet paper that has been suctioned is It can be rotated to a predetermined position while suppressing the acting force that tries to separate from the suction part, and the next sheet paper can be separated without the suction sheet paper falling due to the inflow of air between the next sheet paper and the next sheet paper. becomes easier. In addition, if the sheet paper adsorption section is provided with a pressure roller that presses the sheet paper, it can be rotated around this roller as a fulcrum, so the pressure roller can not only hold the sheet paper in a fixed position without shifting. It strengthens the stiffness of the next sheet of paper that has been suctioned in multiple sheets and promotes its separation effect.

Furthermore, since the sheet paper suction unit is connected to the negative pressure chamber via a deformable or expandable duct, the distance between the sheet paper and the suction unit can be made precise, and the surface condition of the sheet paper can be adjusted. At the worst, it is possible to expect close contact between the sheet paper suction section and the sheet paper, which can greatly contribute to preventing the above-mentioned suction errors.

[Brief explanation of the drawing]

1 and 2 are side sectional views showing a sheet paper suction device according to the present invention, FIG. 3 is a rear view showing substantially the entire sheet paper suction device according to the present invention, and FIG. 4 is a sheet paper suction device according to the present invention. 5(a), (b), and (c) are explanatory diagrams for explaining the operation of the present invention; and FIG. 6 is an explanatory diagram of the operating circuit in the present invention. be. 1: Air suction box body (suction air casing), 2
: Negative pressure chamber, 3: Flexible duct, 5: Sheet paper suction unit, 6: Air suction port, 33: Motor, 39: Sheet paper, 40: Paper feed tray, 61 Nispeed control circuit, 62: Sheet paper suction Detection circuit, 63: Attraction force control circuit. Agent Patent Attorney Aihiko Fuku (and 2 others) No./r!
+

Claims (1)

[Scope of Claims] 1. The sheet paper stacked on the paper feed tray is sucked by air through a suction port provided in the sheet paper suction unit provided oppositely to the sheet paper suction unit. The air suction type sheet paper suction device is characterized in that the sheet paper suction section is rotatably provided, and a speed control means is provided for rotating the sheet paper suction section while gradually accelerating the sheet paper suction section. Air suction type sheet paper adsorption device. 2. The air suction type sheet paper suction device according to claim 1, wherein the sheet paper suction section is provided to be swingable with respect to an air suction section connected to the suction section.