JP2908685B2 - Paper feeding method and paper feeding device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding method and a sheet feeding device for feeding sheets stacked on a sheet feeding table or the like one by one. The present invention relates to a sheet feeding method and a sheet feeding device for sucking and feeding out a sheet floated thereby.

[0002]

2. Description of the Related Art Conventionally, there has been known a sheet feeding apparatus which feeds sheets stacked on a sheet feeding table one by one by using suction force of air (Japanese Patent Laid-Open No. 1-11).
No. 7139). As shown in FIG. 11, the transport belt 3 is disposed above the sheet feeding table 2 on which the sheets 1 are stacked, and an air blowing unit is provided at the upper end of the sheet feeding table 2 on the front side. Also, the height position detecting lever 5 is arranged on the rear side. The transport belt 3 is provided with a large number of suction holes (not shown) throughout the entire sheet. The sheet transporting is performed while the sheet 1 is attracted to the transport belt 3 by the suction unit 6 disposed on the transport belt 3. It can be performed. In such a sheet feeding device, the sheet feeding table 2 is raised and the sheet feeding table 2 is stopped when the uppermost sheet surface 1a of the sheet 1 comes into contact with the height position detecting lever 5, and at the same time, the sheet After air is blown toward the front end of the sheet 1 and the vicinity of the uppermost portion of the sheet 1 is blown, the conveying belt 3 is rotated to adsorb the uppermost sheet to the belt and feed it out.

[0003]

However, in the above-described conventional paper feeder, the height position of the uppermost sheet surface 1a when feeding the sheet 1 is set by the height position detection lever 5, Since the height position of the uppermost sheet 1a is not taken into account at the time of subsequent air blowing, if the air is blown and the sheet 1 is not sufficiently separated, the sheet 1 is surely conveyed. There was a problem that it was not done. That is, when the air suction means 6 as described above is used, in addition to the fact that the uppermost portion of the sheet 1 is sufficiently separated, the sheet 1 at that time is also used.
The distance between the uppermost sheet surface 1a and the conveyor belt 3 is important.
This is because the height of the sheet feed table 2 is accurately controlled and the sheet 1
This is because, even if the position of the uppermost sheet surface 1a is adjusted, when air is blown to the sheet end surface thereafter, there is a possibility that appropriate conveyance may not be performed depending on how the sheet 1 is separated. More specifically, if the uppermost portion of the sheet 1 is not sufficiently separated even when air is blown, the uppermost sheet surface 1a of the sheet 1 is too far from the conveyor belt 3, and the uppermost sheet is not attracted to the conveyor belt 3. On the other hand, if the sheet feeding table 2 is set higher in consideration of the above, the sheet 1 comes into contact with the conveyor belt 3 when the sheet 1 is sufficiently separated, and the sheet 1 is multi-fed. There is a risk of causing a problem.

Accordingly, the present invention adjusts the height of the sheet feeding table after blowing air to the end face of the sheet,
An object of the present invention is to set the uppermost sheet surface of the sheet to an optimum sheet feeding position by changing the degree of the adjustment in accordance with the degree of sheet separation, and to reliably prevent non-feeding and double feeding of sheets.

[0005]

That is, the feature of the paper feeding method according to the present invention is that first, air is blown to the end face of the sheets stacked on the paper feeding table to separate the sheets, and then the uppermost sheet is pressed. Is to detect the amount of sheet deflection, and raise and lower the sheet feeding table based on the detected value.

Secondly, after raising the uppermost sheet surface of the stacked sheets to a predetermined height position, air is blown to the end surface of the sheet to separate the sheets, and then the amount of deflection of the sheet is detected by pressing the uppermost sheet surface. The uppermost sheet is fed by the feeding means after the sheet feed table is moved up and down again based on the detected value.

Further, the sheet feeding apparatus according to the present invention is characterized in that a sheet feeding table for stacking sheets, elevating means for raising and lowering the uppermost sheet surface of the sheets stacked on the sheet feeding table to a predetermined position, and an end face of the sheet. Air blowing means for blowing air onto the sheet, and detecting means for applying a pressing force to the sorted uppermost sheet surface and detecting the amount of deflection of the sheet surface at that time,
There is provided a correction means for raising and lowering the paper feed table again based on the detected value to correct the uppermost paper to a predetermined paper feed position, and a feeding means for feeding the uppermost paper from the predetermined paper feed position.

[0008]

According to the above-mentioned means, after the sheet feeding table on which the sheets are stacked is raised to a predetermined height position, air is blown to the end face of the sheets by the air blowing means to separate the sheets and to remove the separated sheets. A pressing force is applied to the uppermost sheet by the detecting means to detect the amount of deflection of the sheet at that time, and the sheet feeding table is moved up and down again based on the detected value to correct the height position of the uppermost sheet to a predetermined sheet feeding position. Then, the uppermost sheet is fed by the feeding means.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIGS. 1 and 2 show an embodiment of a sheet feeding apparatus according to the present invention. In this paper feeder, reference numeral 10 denotes a paper feed table for stacking sheets 1, which can be moved up and down by table elevating means 22. A kick roller 11 is provided at a central position on the front side above the sheet feeding table 10, and a detecting means 12 for detecting the degree of sheet separation is provided near the kick roller 11. The kick roller 11 includes a stator 13 connected to a vacuum pump (not shown),
3 and a roller section 14 which rotates around.
The roller portion 14 is composed of a pair of right and left substantially cylindrical bodies having a constricted portion 23 formed in the center, and has a flat portion 15 on a part of the outer peripheral surface of the cylindrical body, and rubber or soft plastic on the cylindrical portion. And the like. Further, a large number of small holes 16 penetrating the stator 13 including the friction member 24 are formed in the cylindrical portion. A plurality of the small holes 16 are provided along the cylindrical portion, and the stator 1 corresponding to the opening position of the small hole 16 is provided.
A suction hole 17 is also provided on the lower side of 3.

The kick roller 11 is driven intermittently, as shown in FIG.
As shown in FIG. 3, the flat portion 15 is positioned vertically at the time of paper feeding standby, and the roller portion 14 is
Make a half turn around At this time, the small holes 16 formed in the roller portion 14 sequentially coincide with the suction holes 17 of the stator 13, and the uppermost sheet of the sheets 1 stacked on the sheet feeding table 10 is attracted to the surface of the roller portion 14. Can be.

The kick roller 11 is provided at the tip of an arm 19 having a balancer 18 at the rear end as shown in FIG. The arm 19 can freely rotate around the rotation shaft 20 as a fulcrum. Therefore, the pressing force of the kick roller 11 can be adjusted by changing the position of the balancer 18. Reference numeral 21 is a stopper for determining the lowermost position of the kick roller 11. In this embodiment, the amount of movement of the paper feed table 10 is changed in advance depending on the difference in the paper thickness, and the thick paper is the uppermost sheet of the sheet 1 than the thin paper
a is set so as to approach the kick roller 11. By doing so, when the thick paper is fed by the kick roller 11, not only the suction force but also the frictional force due to the pressing force at the time of rotation acts, but at that time, the balancer 1
The optimum pressing force can be applied to the kick roller 11 only by changing the position of the kick roller 8, and the kick roller 11 can also move freely, so that when the repulsive force from the top sheet 1a is strong, the kick roller 11 escapes upward. It is also possible to easily obtain an optimal frictional force for feeding the sheet. Although the pressing force is adjusted by the balancer 18 in the above-described embodiment, the same operation and effect can be obtained by providing the arm 19 with a spring (not shown) that constantly urges the kick roller 11 downward. Can be

On the other hand, as shown in FIG. 3, the detecting means 12 includes a detecting lever 2 having a rear end fixed to a rotating shaft 25.
6, a servomotor 28 that applies a rotational force to the detection lever 26 via a pinion gear 27, and a potentiometer 2 that converts the rotation angle of the detection lever 26 into a voltage value and outputs the voltage value.
9. The detection lever 26 is disposed at the center of the kick roller 11.
The tip of the detection lever 26 is rotated when the kick roller 11 is rotated.
Is arranged so as to be inserted into the constricted portion 23 at the center. As a result, the detection lever 26 is normally rotated upward as shown in FIG. 1 and is separated from the paper surface, but when detecting the amount of deflection on the paper surface, the servo motor 28 is used.
Is rotated counterclockwise by the driving of the kick roller 11.
, The uppermost sheet surface 1a of the sheet 1 can be pressed. The detection of the amount of deflection of the paper surface is not limited to detecting not only a depression of the paper surface of the pressed portion when the uppermost paper surface 1a is pressed but also detecting the entirety of the paper surface when the entirety of the uppermost paper surface 1a is bent. Including.

The paper feeder has a paper feed table 10.
Air blowing devices 31 are arranged on both left and right sides of FIG. 1 (only one is shown in FIG. 1). This air blowing device 31
An air nozzle 33 is provided at the tip of the air supply pipe 32, and air is blown toward the end surface of the sheet 1 set at a predetermined height position. In this way, the air blown out from the left and right air nozzles 33 causes the front side of the uppermost portion of the sheets 1 stacked on the sheet feed table 10 to be discarded, so that the sheets 1 float. The height position of the air nozzle 33 is near the uppermost sheet surface 1a of the sheet 1 as shown in FIG. 2, but in particular, as shown in FIG. By setting the center axis 36 of the nozzle 33 to be slightly higher than the uppermost sheet surface 1a of the sheet 1 when the sheet 1 is discarded, the sheet can be separated from dense to coarse in the uppermost sheet direction.

A feed roller 40 for transporting the sheet 1 fed from the kick roller 11 is provided in front of the kick roller 11, and a reverse rotation is provided near the lower portion of the feed roller 40. A separation roller 41 is provided. These feed roller 40 and separation roller 41
Is connected to the vacuum pump via a solenoid valve,
Like the kick roller 11, the sheet 1 is suction-conveyed to the surface thereof. The paper feed roller 40 includes a support shaft 4
2 and a roller 43 rotating around the roller 2. A friction member 50 similar to the kick roller 11 is attached to the outer peripheral surface of the roller portion 43.
Many small holes 44 are provided over the entire peripheral surface. Further, inside the roller portion 43, suction holes 45 communicating with the small holes 44 are provided radially.
5 and a small hole 44 communicate with a vacuum pump through a suction member 46 attached to one side of the paper feed roller 40. That is, as shown in FIG. 1 and FIG.
A connection port 48 for the vacuum hose 47 is opened in the lower part of the housing, and a recess 49 following the connection port 48 is provided on the inner side, so that the recess 49 and the suction hole 45 communicate with each other. I have. The size of the concave portion 49 corresponds to one of the suction holes 45. When the roller portion 43 rotates, each of the radially provided suction holes 45 sequentially communicates with the concave portion 49. Connected suction hole 4
It can be sucked through the small hole 44 following 5.

On the other hand, the separation roller 41 includes a hollow shaft 51 and a roller portion 52 rotating around the hollow shaft 51 similarly to the kick roller 11 described above. Then, as shown in FIG. 6, the suction hole 5 of the hollow shaft 51 provided upward.
Numeral 3 is disposed close to the suction hole 45 of the paper feed roller 40 so as to be substantially opposite to the suction hole 45. Also,
As shown in FIG. 1, the roller portion 52 in the longitudinal direction has a several places of the constricted portion 59 is formed shaped, tip their constricted portion 59 formed in a comb-shaped guide member 54 of the cylinder The department is involved. Therefore, the sheet 1 fed from the kick roller 11 is guided by the leading end of the guide member 54 and is smoothly fed to the sheet feeding roller 40. As shown in FIG. 2, a friction member 58 is attached to the outer periphery of the roller unit 52 in the same manner as the roller unit 43 of the paper feed roller 40, and a small hole 55 is provided all around. In addition, this small hole 5
As shown in FIG. 6, the peripheral edge portion 5 has a corner 56 on the rear side with respect to the rotation direction. By dropping this corner 56, even if the leading end of the sheet 1 fed from the kick roller 11 is sucked by the separation roller 41, it can be prevented from being caught on the peripheral edge of the small hole 55.

A front end detection sensor S1 and a rear end detection sensor S2 of the conveyed sheet are provided in front of the paper feed roller 40 and the separation roller 41, respectively, and a pair of pinch rollers 57 are disposed in front of the sensors. After detecting the edge of the sheet with the detection sensors S1 and S2, the sheet is fed to a transport path (not shown).

Pressing members 34 (only one is shown) are disposed on both rear sides of the sheet supply table 10 for restricting variations in the rear side of the sheet 1 when the sheet is blown by blowing air. I have. As shown in FIG. 2, the pressing member 34 is disposed at a rear side of the sheet feeding table 10 within a range of a feeding length X forward from a rear end position P1 of the sheet 1 on the sheet feeding table 10. Is the feed length X
Has a positional relationship of L ≧ X with respect to the feed length L from the front end position P2 of the sheet 1 on the sheet feeding table 10 to the separation position P3 between the sheet feeding roller 40 and the separation roller 41. As a result, it is possible to prevent the rear end of the sheet 1 from being displaced when the sheet 1 is blown by the air blowing device 31, and in this state, the kick roller 11 can feed out the sheet 1 and at the separation position P3, Since the rear end of the sheet is not restrained by the pressing member 34, the sheet conveyance by the sheet feeding roller 40 is not hindered.

Next, a paper feeding method will be described with reference to a time chart shown in FIG. The height position of the sheet feeding table 10, the pressing force of the detection lever 26, the air blowing device 31
The control conditions for paper feeding such as air pressure are automatically set by inputting information such as paper size and paper thickness from an operation panel. First, when the power switch on the operation panel is turned on, the paper feed roller 40 and the separation roller 41 start to rotate, and further, the suction of the separation roller 41 starts. Next, when the start button is pressed, the paper feed roller 40 starts sucking, and at the same time, the paper feed table 10 rises, and the leading end of the detection lever 26 hits the uppermost sheet surface 1 a of the sheet 1. The detection lever 26 rotates upward while pressing the uppermost sheet surface 1a as the sheet feeding table 10 further moves up, and stops the rising of the sheet feeding table 10 when the sheet feeding table 10 is rotated to a predetermined angle. 1a is set at a predetermined height position. At about the same time when the detection lever 26 rotates upward and separates from the uppermost sheet surface 1a of the sheet 1, air is blown from the air nozzles 33 on both sides toward the front end surface of the sheet 1, and the uppermost portion of the sheet 1 The neighborhood is judged.

Next, the sheet 1 thus sorted is used.
The uppermost paper surface 1a is hit with the tip of the detection lever 26, and the uppermost paper surface 1a is pressed with a predetermined torque to bend the sheet 1. The pressing force of the detection lever 26 at this time is not so large, and is such that the floating of the uppermost sheet is maintained even when pressed. Then, a voltage value corresponding to the rotation angle θ of the detection lever 26 obtained at the time of bending is obtained from the potentiometer 29 as the amount of bending on the paper surface. Then, this voltage value is compared with a reference voltage value set in advance by the correction means of the control unit to calculate a correction value, and based on the correction value, the sheet feeding table 10 is moved up and down again and the sheet 1 is moved. Is set to the final paper feed position. The detection lever 26 is located on the uppermost sheet surface 1a of the sheet 1.
Immediately after hitting, it rotates upward and returns to the original standby position.

The control for correcting the height position is performed, for example, when the sheet 1 is sufficiently separated by blowing the air from the air nozzle 33 as shown in FIG. 8 or as shown in FIG. This is based on the fact that there is a difference in the rotation angle θ of the detection lever 26 between the cases where the separation is insufficient. That is, from the rotation angle θ1 of the detection lever 26 when the sheet is sufficiently separated as shown in FIG. 8 and the upper part of the sheet is rough, as shown in FIG. The rotation angle θ2 of the detection lever 26 in the dense state is larger. Therefore,
In this case, the raising width h of the sheet feeding table 10 in FIG.
9, the uppermost sheet surface 1a of the sheet 1 is brought closer to the kick roller 11 by increasing the raising width h2 of the sheet feeding table 10 in FIG. In this manner, by adjusting the final height of the sheet feed table 10 according to the degree of sheet separation, the sheet feed position of the sheet uppermost sheet surface 1a with respect to the kick roller 11 can be corrected.

FIG. 10 shows the uppermost sheet 1a as described above.
Is corrected, the height position of the uppermost paper surface 1a is made the same between the case where the separation is sufficient as shown in (a) and the case where the separation is insufficient as shown in (b). Later
The state when the uppermost sheet surface 1a is pressed again by the detection lever 26 to detect the degree of bending of the sheet is shown. In this case, when the discrimination is sufficient (a), the deflection of the uppermost paper surface 1a becomes larger, so that the rotation angle θ1 of (a) is inevitably smaller than the rotation of (b) where the discrimination is insufficient. The angle θ2 is larger than the angle θ2, and conversely, the raising width of the sheet feeding table 10 in (a) is made larger than that in (b), and the uppermost sheet surface 1a is set to an appropriate sheet feeding position. Such height position control is used, for example, when adjusting the sheet feeding position of the top sheet 1a a plurality of times when feeding out the first sheet, or when feeding out two or more stacked sheets.

In any of the cases shown in FIGS. 8 to 10, the uppermost sheet of the stacking sheet is unnecessarily separated and floated excessively, so that the voltage value detected by the detection lever 26 is smaller than the reference voltage value. When the size becomes smaller, the correction control for lowering the height position of the uppermost sheet surface 1a by lowering the sheet supply table 10 is performed in a manner opposite to the above.

Next, the kick roller 11 is driven to make a half turn. At this time, the floating uppermost sheet is sucked by the kick roller 11 and fed out. The leading end of the sheet 1 fed by the kick roller 11 has a guide member 54.
The paper is fed between the paper feed roller 40 and the separation roller 41 along the comb-shaped tip, and is attracted to the paper feed roller 40. Then, the sheet is further fed to the pinch roller 57 via the front and rear sheet edge detection sensors S1 and S2. In this case, when only the uppermost sheet is fed by the kick roller 11, the sheet is sucked by the negative pressure of the suction hole 45 of the sheet feeding roller 40 immediately before reaching the position of the suction hole 53 of the separation roller 41. Even if it is sucked from below by the separation roller 41, that effect is not affected. On the other hand, if the kick roller 11 has fed out the sheet below it along with the uppermost sheet, the uppermost sheet is sucked by the feed roller 40 in the same manner as described above, but the lower sheet is separated by the separation roller 41. Since it is pulled back in the opposite direction by being sucked, it is possible to prevent the paper from being sent to the pinch roller 57 together with the uppermost sheet. In particular, in this embodiment, the sheet 1 is moved along the comb-shaped guide member 54 by the feed roller 4.
The leading edge of the sheet 1 is not entangled by the separation roller 41 because the sheet is fed to the position 0.

After detecting the leading edge of the fed sheet by the leading edge detecting sensor S1, the detecting means 12 is driven again a predetermined time later, and the detecting lever 26 is rotated to hit the uppermost sheet surface 1a of the stacked sheet, and the deflection at that time is performed as described above. The degree of sheet separation is measured based on the amount, and the height of the sheet feeding table 10 is adjusted according to the rotation angle θ of the detection lever 26.
After the trailing edge of the fed sheet is detected by the trailing edge detection sensor S2, the kick roller 1
1 is driven to feed out the uppermost sheet, and the sheet is fed by the same means as described above. In this way, every time the uppermost sheet is fed one by one, the continuous feeding is performed while the height of the uppermost sheet surface 1a is corrected by the detecting means 12.

[0025]

As described above, according to the sheet feeding method and the sheet feeding apparatus according to the present invention, the degree of sheet separation when air is blown to the end surface of the sheet is determined by pressing the uppermost sheet surface and bending the sheet. Since the paper feed table is moved up and down based on the detected amount of deflection when the paper is fed, the height position of the uppermost sheet is always set to a predetermined paper feed position regardless of the degree of separation. be able to. As a result, feeding during suction feeding becomes reliable, and non-feeding and double feeding of sheets can be reliably prevented. Also,
Each time the top sheet is fed one by one, the amount of deflection of the top sheet is detected, and the height position of the top sheet is corrected each time, so that continuous feeding can be performed at high speed and reliably. .

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a sheet feeding device according to the present invention.

FIG. 2 is a schematic side view of the sheet feeding device.

FIG. 3 is a perspective view illustrating a detecting unit that detects a degree of sheet separation.

FIG. 4 is an explanatory diagram showing a height position of an air nozzle.

FIG. 5 is a sectional view of a sheet feeding roller.

FIG. 6 is a cross-sectional view illustrating a positional relationship between small holes between a sheet feeding roller and a separation roller.

FIG. 7 is a time chart for controlling the paper feeding method according to the present invention.

FIG. 8 is an explanatory diagram in a case where a sheet deflection is detected by a detection lever.

FIG. 9 is an explanatory diagram in the case of detecting a sheet deflection that is insufficiently separated;

FIG. 10 is an explanatory diagram in a case where a sheet deflection is detected again after height position adjustment.

FIG. 11 is a schematic view showing an example of a conventional sheet feeding device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sheet 1a Top paper surface 10 Feeding table 11 Kick roller 12 Detecting means 22 Elevating means 26 Detecting lever 31 Air blowing device (Air blowing means)

Continued on the front page (72) Inventor Toshiro Fukasawa 430-1, Kobayashi, Masuho-cho, Minamikoma-gun, Yamanashi Prefecture Inside Niska Corporation (72) Inventor Kuniaki Obuchi 430-1, Kobayashi, Masuho-machi, Minamikoma-gun Yamanashi Prefecture Inside NISKA Corporation (72) Inventor Hiroo Kono 430-1 Kobayashi, Masuho-cho, Minamikoma-gun, Yamanashi Prefecture Inside NISKA CORPORATION (58) Field surveyed (Int.Cl. ⁶ , DB name) B65H 1/00-3/68

Claims (5)

(57) [Claims] 1. A sheet stacked on a sheet feed table is blown with air to separate the sheet, and then the uppermost sheet is pressed to detect the amount of sheet deflection, and the sheet feed table is raised and lowered based on the detected value. A sheet feeding method characterized by causing the sheet to be fed. 2. After raising the uppermost sheet surface of the stacked sheets to a predetermined height position, air is blown to the end surface of the sheet to separate the sheets, and then, by pressing the uppermost sheet surface, the amount of deflection of the sheet is detected. A paper feeding method characterized by feeding the uppermost sheet by feeding means after the sheet feeding table is raised and lowered again based on the value. 3. A sheet feeding table for stacking sheets, lifting means for raising and lowering the uppermost sheet surface of the sheets stacked on the sheet feeding table to a predetermined position, and air blowing for blowing the sheet by blowing air to the end face of the sheet Means, a detecting means for applying a pressing force to the sorted uppermost sheet surface and detecting a deflection amount of the sheet surface at that time, and re-elevating the sheet supply table based on the detected value to correct the uppermost sheet to a predetermined sheet supply position. A feeding device for feeding the uppermost sheet from a predetermined feeding position. 4. The sheet feeder according to claim 3, wherein said detecting means applies a pressing force to the uppermost sheet at a position substantially immediately below said feeding means. 5. The detecting means includes: a detecting lever for pressing an uppermost sheet surface of a sheet stacked on a sheet feeding table; a driving mechanism of the detecting lever; and a detection when the uppermost sheet surface is deflected by the detecting lever. 5. The sheet feeding device according to claim 3, further comprising a detector that detects a displacement amount of the lever.