JP3564352B2 - Paper feeder - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a sheet feeding device suitable for use in a sheet-fed printing press, and more particularly, to a sheet feeding device for continuously feeding sheets stacked on a sheet feeding table one by one from the top.
[0002]
[Prior art]
A sheet-fed printing press is generally provided with a sheet feeding unit having a sheet elevating device (hereinafter, simply referred to as a sheet feeding device). FIG. 11 is an overall schematic configuration diagram of a sheet feeding device provided in a conventional sheet-fed printing press, FIG. 12 is an explanatory diagram illustrating an example of a warped deformation state of a stacked sheet, and FIG. 13 illustrates a problem in the conventional sheet feeding device. FIG.
[0003]
A sheet feeding device (also referred to as a continuous sheet feeding device) 1 in the sheet-fed printing press is provided upstream of the printing press, and as shown in FIG. The function is such that the sheet is sequentially carried out from the side, and is conveyed one by one to the printing apparatus section in the next process via the feeder board section 20.
As shown in FIG. 11, the sheet feeding device 1 includes a sheet feeding table 5, a sheet elevating device 14 that moves the sheet feeding table 5 up and down, and elevates and lowers the sheets 9 </ b> A stacked on the sheet feeding table 5. It has a separator device 8 that sucks and holds one uppermost sheet 9A of the sheet pile 9 stacked on the paper table 5 by the vacuum suction pad 21 and carries it out downstream. Hereinafter, a stack of the plurality of sheets 9A is referred to as a sheet pile 9.
[0004]
The sheet elevating device 14 lifts and lowers the sheet supply table 5 through the suspension chains 2, 2 for suspending the sheet supply table 5, the sprockets 3, 3 for winding the chain 2, and the suspension chains 2, 2. An elevating drive motor 4 to be driven, an upper surface sensor 12 for detecting the height of the uppermost surface of the sheet pile 9, a control device 11 for controlling the elevating drive motor 4 based on a detection signal from the upper surface sensor 12, and a control device 11. And an arithmetic unit 10 for calculating input data to the computer. Reference numeral 16 in FIG. 8 denotes a blade that regulates the front end position of each sheet 9A and swings in conjunction with the feeding timing.
[0005]
In the feeder board section 20, the sheet 9A is carried in between the pair of feeding rollers 22, and is conveyed to the next step by the belt 20A wound around one of the feeding rollers 22.
The conventional sheet feeding device is configured as described above, and operates as follows.
First, the sheets 9A are stacked on the pallet 5A as a preparation for printing, and then the pallet 5A is placed on the sheet feeding table 5 via a conveying unit (not shown). Subsequently, the control device 11 receives a signal from the upper surface sensor 12 through the arithmetic device 10 until the upper surface sensor 12 detects that the upper surface of the sheet (the uppermost sheet 9A of the sheet pile 9) has reached a predetermined height. The lifting drive motor 4 is operated. As a result, the feed table 5 is raised via the sprockets 3 and 3 and the suspension chains 2 and 2, and the height position of the uppermost surface of the stacked sheet 9 is set to a position detected by the upper surface sensor 12. You.
[0006]
In this state, printing is started.
During printing operation, the uppermost sheet 9A of the sheet pile 9 is sucked and held by the vacuum suction pad 21 provided on the separator device 8, and is carried out downstream. Thereafter, predetermined printing is performed in the printing device unit, and the printing device is sent to the paper discharge unit.
At this time, unloading of the sheet 9A from the sheet feeding device is controlled by the control device 11 and is performed continuously.
[0007]
By the way, since the sheets 9A are sequentially conveyed one by one, the height of the entire stacked sheet is reduced in accordance with the thickness and the number of the conveyed sheets 9 with printing. For this reason, a signal is sent from the control device 11 to operate the elevating drive motor 4 so that the height of the uppermost surface of the sheet pile 9 that becomes lower in accordance with the number of conveyed sheets is fixed, and the feed table 5 is moved. Raise continuously or stepwise.
[0008]
At this time, the thickness of the sheet pile 9 and the number of consumed sheets 9A are input to the arithmetic unit 10, and the arithmetic unit 10 calculates the thickness of the sheet pile 9 and the number of consumed sheets 9A, The controller 11 raises the sheet supply table 5 in accordance with the prediction of the lowering of the upper surface, or the upper surface of the stacked sheet piles 9 is detected by the upper surface sensor 12 in the same manner as when preparing for printing. By moving up the sheet feeding table 5 until the upper surface sensor 12 is activated when the area is out of the area, the height of the uppermost surface of the sheet pile 9 is maintained at a fixed position.
[0009]
[Problems to be solved by the invention]
By the way, in the above-described conventional sheet feeding device (continuous sheet feeding device) 1, when the height position of the sheet feeding table 5 is controlled, the elevation amount is controlled by the upper surface sensor 21 provided at one position in the width direction. However, there were the following problems.
That is, the sheet 9A placed on the sheet feeding table 5 may have a large undulation. This undulation often appears when printing is performed on one side of the sheet 9A and the back side of the sheet 9A, but is caused by environmental conditions such as humidity and other various conditions in the manufacturing process. When the sheet 9A of the sheet pile 9 is viewed from the side to which the sheet 9A is supplied, a warp often occurs as shown in FIG. 12A, and in addition, a downward warp as shown in FIG. Various deformations such as the waveform deformation shown in FIGS. 12C and 12D may also occur.
[0010]
When the sheet 9A is thus deformed, the height of the uppermost surface of the sheet pile 9 is naturally not uniform, and the detected upper surface position of the sheet detected by the upper surface sensor 12 is different from the actual uppermost surface position. In this case, a paper feed failure may occur.
That is, as shown in FIG. 13A, when the height position of most of the upper surface of the sheet is too high with respect to the reference height (supply allowable range) detected by the upper surface sensor 12, the front end of the sheet moves the wing plate 16. When the sheet gets over to the feeding roller 22 side, the sheet position is greatly shifted from the regulation position, the sheet cannot be positioned, and a printing error occurs in a subsequent process, or an error occurs in the sheet delivery, and various other causes. Trouble occurs.
[0011]
Further, as shown in FIG. 13B, when the height position of most of the upper surface of the sheet is too low with respect to the reference height (supply allowable range), the sheet 9A hits the wing plate 16 and gets over. Troubles such as paper jams occur. .
When each of these problems occurs, it is necessary to perform repair / restoration work while stopping the machine, and the operating rate of the printing press is reduced. Therefore, in order to prevent this problem, it is necessary for the operator to adjust the elevation of the sheet feeding table 5 while visually checking the sheet feeding state, and various problems such as poor work efficiency are caused. there were.
[0012]
The present invention has been made in view of the above-described problems, and enables the sheet to be reliably fed to the next process by properly adjusting the vertical position of the sheet even if the sheet is deformed such as undulation. It is an object of the present invention to provide a paper feeding device.
[0013]
[Means for Solving the Problems]
For this reason, the sheet feeding apparatus according to the first aspect of the present invention adjusts the vertical position of a sheet pile in which a plurality of sheets are stacked and feeds the sheet to the next process in order from the upper sheet of the sheet pile. A paper device, an elevating mechanism for elevating the sheet pile,The sheet pile is provided at a plurality of positions in the width direction of the sheet pile.An upper surface sensor for detecting the upper surface of the sheet pile,The reference of one of the plurality of upper surface sensorsA sheet elevating device comprising control means for controlling the operation of the elevating mechanism based on a detection signal from the upper surface sensor and elevating the sheet pile in response to consumption of the sheet;UpOf the multiple top sensorsIncluding at least the reference top sensorSensor elevating means for moving at least one of the sheet piles in the vertical direction is provided, and the control means controls the upper surface of the sheet pile based on detection signals from the plurality of upper surface sensors prior to or during the paper feeding. The shape is grasped, and the sensor elevating means is operated in accordance with the grasped top shape.Of the standardThe vertical position of the upper surface sensor is corrected.
[0014]
The plurality of upper surface sensors areAnyFeeding direction of the sheet pileInstalled on the sidePreferably, the upper surface sensor is provided in a sheet feeding direction of the sheet pile.~ sideIt is preferable that they are disposed near the center in the left-right width direction and at the ends in the left-right width direction, respectively..
[0015]
further,The control means determines the amount of warpage generated in accordance with the warpage deformation of the upper surface of the sheet pile based on a detection signal from the plurality of upper surface sensors prior to or during the paper feeding. The height of the upper surface of the sheet pile is detected as a difference between the high position and the low position, and the vertical position of the reference upper surface sensor is set to an intermediate height between the high position and the low position of the upper surface position. Correct toIs preferable (claim4).
Further, the present paper feeding device is preferably used for feeding a printing sheet to a printing device of a sheet-fed printing press.5).
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, a first embodiment of the present invention will be described. FIGS. 1 to 5 show a sheet feeding apparatus as a first embodiment of the present invention, and FIG. 2 is an enlarged view of a portion B in FIG. 1, FIG. 3 is a diagram showing a sheet position detection system thereof, and FIG. 2 (b) is a diagram corresponding to FIG. (B) is a diagram corresponding to FIG. 2 (b)], and FIGS. 4 and 5 are diagrams illustrating the operation of the paper feeding device in the order of (a) to (d).
[0017]
A sheet feeding device (also referred to as a continuous sheet feeding device) 1 according to the present embodiment is installed in an upstream portion of a sheet-fed printing press, and as shown in FIG. 9A are stacked, and sequentially carried out from the uppermost sheet 9A of the plurality of sheets 9A (hereinafter, referred to as the sheet pile 9). Functions to transport to
[0018]
As shown in FIG. 1, the sheet feeding device 1 includes a sheet feeding table 5, a sheet elevating device 14 that moves the sheet feeding table 5 up and down to raise and lower the sheets 9 </ b> A stacked on the sheet feeding table 5, It has a separator device 8 that sucks and holds one uppermost sheet 9A of the sheet pile 9 stacked on the paper table 5 by the vacuum suction pad 21 and carries it out downstream.
[0019]
As shown in FIGS. 1 and 2, the sheet elevating device 14 according to the present embodiment includes a suspension chain 2, 2 for suspending the sheet feeding table 5, and sprockets 3, 3 around which the chain 2 is wound. An elevating drive motor 4 that drives the feed table 5 up and down through the suspension chains 2 and 2 and a top sheet 9A of the sheet piles 9 stacked on the feed table 5 are converted into a plurality of sheets 9A. The first upper sensor 12 and the second upper sensor 13 for detecting the height position of the front end of the uppermost surface of the sheet pile 9 formed by stacking, and the lifting mechanism 14 based on the detection outputs of the first and second upper sensors B13. Is driven to move the sheet pile 9 up and down so that the uppermost position of the sheet pile 9 (the position of the uppermost sheet 9A of the sheet pile 9) becomes a predetermined height (within the supply allowable range) (control means). 11 and control device 11 It is configured to include an arithmetic unit 10 for calculating the input data.
[0020]
The elevating mechanism 14A is composed of the suspension chains 2, 2, the sprockets 3, 3, and the elevating drive motor 4.
In addition, reference numeral 16 in FIG. 1 denotes a blade that regulates the front end position of each sheet 9A and swings in conjunction with the feeding timing.
In the case of the present embodiment, the first upper surface sensor 12 is disposed substantially at the center in the lateral width direction (substantially at the center in the left-right width direction) at the upper part (uppermost front end) of the sheet pile 9 on the sheet feeding direction side. In addition, it is configured to be able to move up and down by a predetermined amount via an upper surface sensor elevating device (sensor elevating means) 15.
[0021]
On the other hand, the second upper surface sensor 13 is disposed close to the lateral side surface of the sheet pile 9 (at the left and right width direction ends). Note that the second upper surface sensor 13 is fixed at the same position after the initial adjustment.
Further, in the arithmetic unit 10, the deformation direction of the sheet pile 9, that is, whether the sheet pile 9 is in the upwardly warped state or the downwardly warped state, is determined by a plurality of (two in this case) upper surface sensors 12 and 13 in the sheet width direction. The determination can be made based on the upper surface detection operation order and the difference between the upper surface detection timing. Further, in the arithmetic unit 10, the amount of warpage deformation (S) of the sheet 9A is different from the elevating speed (V) of the sheet feeding table 5 on which the sheets 9A are stacked and the timing at which each of the upper surface sensors 12 and 13 operates. The calculation is made based on the operation time difference (T).
[0022]
As means for determining the amount of warpage deformation (S) of the sheet 9A, as described above, the elevation speed (V) of the sheet feeding table 5 (that is, the sheet pile 9) and the time difference (T) at which the upper surface sensors 12 and 13 operate. The rotation angle (number of rotations) of a sprocket 3 around which a part of the sheet elevating device 14, for example, the sheet supply table suspension chain 2 is wound, is calculated. It is also possible to adopt various methods, such as measuring and calculating via measuring means such as an encoder connected to the sprocket shaft.
[0023]
Since the sheet feeding device according to the first embodiment of the present invention is configured as described above, it operates as follows.
First, a case where the sheet 9A is warped as shown in FIG. 4 will be described. In this case, first, as shown in FIG. 4A, the heights of the first upper surface sensor 12 and the second upper surface sensor 13 are set to a preset reference height position (horizontal height position) as an initial state. I do.
[0024]
Next, as shown in FIG. 4B, the lifting drive motor 4 is operated to raise the sheet feeding table 5 on which the sheet pile 9 is mounted. By this operation, in this case, first, the second upper surface sensor 13 detects the upper surface (uppermost sheet 9A) of the uppermost sheet 9A of the sheet pile 9.
Subsequently, after a lapse of a predetermined time (T seconds), the first upper surface sensor 12 operates to detect the upper surface of the uppermost sheet 9A. The time difference (T) between the operation timings of the second upper surface sensor 13 and the first upper surface sensor 12 is sent to the arithmetic unit 10, and after the warpage amount (S) is measured via the arithmetic unit 10, Sent in. Note that the warpage amount S is calculated as S = V × T, where V is the lifting / lowering speed and Ts is the time difference between sensor operations.
[0025]
Next, as shown in FIG. 4C, the sheet pile 9 is lowered via the control device 11 by half the time difference (T), that is, by T / 2 (seconds). That is, the sheet pile 9 is lowered by half the amount of warpage (S), that is, by a height of S / 2 (cm). As a result, the reference height position of the uppermost sheet 9A is set to the intermediate height of the warpage (S).
[0026]
Next, as shown in FIG. 4D, the upper surface sensor elevating device 15 is operated to be lowered and fixed until the first upper surface sensor 12 detects the upper surface of the uppermost sheet 9A.
After the setting, the control unit 11 corrects and controls the height position of the sheet 9 with reference to the first upper surface sensor 12 during paper feeding.
As described above, in addition to the operation of lowering the sheet pile 9 as shown in FIG. 4C and the operation of lowering the first upper surface sensor 12 as shown in FIG. Conversely, the operation of lowering the first upper surface sensor 12 may be performed as shown in FIG. 4D, and then the operation of lowering the sheet pile 9 may be performed as shown in FIG. 4C.
[0027]
Next, a case where the sheet 9 is warped downward as shown in FIG. 5 will be described. In this case, as described above, first, as shown in FIG. 5A, the heights of the first upper surface sensor 12 and the second upper surface sensor 13 are set to the horizontal position as an initial state.
Next, as shown in FIG. 5B, the lifting drive motor 4 is operated to raise the sheet feeding table 5 on which the sheet piles 9 are stacked. By this operation, in this example, first, the first upper surface sensor 12 operates to detect the upper surface of the uppermost sheet 9A of the sheet pile 9, and then, after a predetermined time (T seconds), the second upper surface sensor 13 operates. Then, the upper surface of the uppermost sheet 9A is detected.
[0028]
Then, the time difference (T) between the operation timings of the first upper surface sensor 12 and the second upper surface sensor 13 is sent to the arithmetic unit 10, and the arithmetic unit 10 calculates the warpage amount (S) in the same manner as described above.
Next, as shown in FIG. 5C, the sheet feeding table 5 is raised by T / 2 (seconds). That is, the sheet pile 9 is lifted by S / 2 (cm). As a result, the reference height position of the stacking sheet 9 is set to the middle height of the warpage (S).
[0029]
Next, as shown in FIG. 5D, the upper surface sensor elevating device 15 is operated, and the first upper surface sensor 12 is raised and fixed at the same position until the first upper surface sensor 12 detects the upper surface of the sheet pile 9. I do.
After the setting, the control unit 11 corrects and controls the height position of the sheet 9 with reference to the first upper surface sensor 12 during paper feeding.
[0030]
In the general case, the warpage (S) of the entire stacked sheet 9 increases as the number of sheets increases. That is, as the consumption accompanying printing progresses and the number of sheets decreases, the amount of warpage (S) decreases.
Therefore, according to the sheet feeding device of the present embodiment, the sheet warpage amount (S) is measured and corrected as compared with the conventional method (apparatus) that controls the upper surface of the stacked sheets at a specific position on the upper surface of the sheet. In this state, the height of the uppermost sheet is controlled, so that the sheet can be supplied more stably.
[0031]
As a result, it is possible to reduce the number of paper feed troubles, reduce the number of waste sheets, and obtain the effect of improving the operation rate of the printing press, that is, the productivity. In addition, as a type other than the above example, the present apparatus is provided with a plurality of sets of upper surface sensors more than two sets in the width direction of the sheet pile 9, for example, an upper surface sensor that detects the lowest position of the uppermost stage of the sheet pile 9. The upper surface sensor that can be moved up and down is moved to half of the difference between these positions based on the upper surface sensor that has detected the uppermost position, and the height position of the uppermost sheet pile 9 is moved by this upper surface sensor. By controlling, it is possible to set (control) a position where stable operation can be performed even for a stacked sheet having a complicated warp deformation.
[0032]
Next, a second embodiment of the present invention will be described. FIGS. 6 to 8 show a sheet feeding device according to a second embodiment of the present invention, and FIG. 6 shows a sheet position provided in the sheet feeding device. FIGS. 7 and 8 show a detection system, and FIGS. 7 and 8 illustrate the operation in the order of (a) to (d).
The paper feeder according to the present embodiment is provided with an upper surface sensor elevating device (sensor elevating means) 15 on the second upper sensor 13 side in addition to the configuration of the first embodiment.
[0033]
That is, as shown in FIG. 6, the present apparatus is provided with a first upper surface sensor 12 disposed at the center of the sheet pile 9 in the width direction to detect the height position of the front end of the sheet pile 9, The second upper surface sensor 13 which is disposed in the section and detects the height position of the front end of the sheet pile 9 can be independently raised and lowered via upper surface sensor lifting devices (sensor raising and lowering means) 15 and 15 provided respectively. It is configured to be able to.
[0034]
Since the sheet feeding device according to the second embodiment of the present invention is configured as described above, the sheet feeding device according to the first embodiment moves the first upper surface sensor 12 at the center in the width direction according to the deformation of the sheet. In addition to controlling the upper surface position of the stacked sheet, in the present embodiment, the upper surface sensor of the lower surface of the upper surface of the sheet pile 9 of the upper surface sensors 12 and 13 is moved to the intermediate height of the amount of the undulation. The upper surface sensor is moved and used for position control of the upper surface of the sheet.
[0035]
Therefore, when the sheet 9A is warped, the operation is the same as that of the first embodiment as shown in FIGS. 7A to 7D, and the description is omitted.
On the other hand, a case where the sheet 9A is warped downward as shown in FIG. 8 will be described.
In this case, as in the first embodiment, first, as shown in FIG. 8A, the heights of the first upper surface sensor 12 and the second upper surface sensor 13 are set to predetermined horizontal positions as an initial state. Next, as shown in FIG. 8B, the lifting drive motor 4 is operated to raise the sheet feeding table 5 on which the sheets 9 are stacked.
[0036]
By this operation, first, the first upper surface sensor 12 operates to detect the upper surface of the uppermost sheet.
Subsequently, after a lapse of a predetermined time (T seconds), the second upper surface sensor 13 operates to detect the upper surface of the uppermost sheet.
Then, an operation timing difference between the first upper surface sensor 12 and the second upper surface sensor 13, that is, a time difference (T) s is sent to the arithmetic unit 10, and the warpage amount (S) is calculated via the arithmetic unit 10. After that, it is sent to the control device 11.
[0037]
Next, as shown in FIG. 8C, the sheet pile 9 is lowered by T / 2 (seconds) via the control device 11, and the sheet pile 9 is lowered by S / 2 (cm). As a result, the reference height position of the uppermost sheet 9A is set at an intermediate height of the warpage (S).
Next, as shown in FIG. 8D, the upper surface sensor elevating device 15 is operated to lower the sheet pile 9 until the second upper surface sensor 13 on the lower side detects the upper surface position of the sheet pile 9. And fix it.
[0038]
After that, the height position of the sheet pile 9 is corrected and controlled with reference to the second upper surface sensor 13 side.
The present embodiment functions as described above. The lower side of the sheet pile 9 against the warp deformation of the sheet 9A (the first upper surface sensor 12 at the center in the width direction in the case of upward warp, and the width direction in the case of downward warp) The height position of the uppermost surface of the sheet feed table 5, that is, the sheet pile 9, is controlled based on the surface of the second upper surface sensor 13) at the side end.
[0039]
As described above, the present embodiment is configured such that the position is controlled based on the lower part of the uppermost surface of the stacking sheet regardless of the state of the upward warpage deformation and the downward warpage deformation. Even when the number of sheets decreases, the variation in the amount of warpage deformation is small, and particularly when the sheet is deformed downward, there is an advantage that the sheet feeding state becomes more stable and reliable as compared with the first embodiment. . That is, the amount of deformation of the sheet is generally large when a large number of sheets 9Aa are stacked, and becomes small when the stacked weight of the sheet 9A is small. This makes it possible to obtain an effect such as a smooth driving.
[0040]
As a modification of the present embodiment, as shown by a dashed line in FIG. 6, a plurality of sets of upper surface sensors more than two sets are arranged in the sheet width direction, and the upper surface where the highest position and the lowest position are detected is detected. If the reference height position of the uppermost sheet 9 is set based on the sensor, the upper surface sensor that detects the lowermost position is moved by S / 2, and this sensor is selected as a sensor for controlling the upper surface position of the sheet, it is complicated. It is possible to control a more ideal height position even for a warped stacked sheet.
[0041]
Next, a third embodiment of the present invention will be described. FIGS. 9 and 10 show a sheet feeding device as a third embodiment of the present invention. FIG. 9 shows a sheet position provided in the sheet feeding device. FIG. 10 is a diagram showing the relative relationship between the number of stacked general stacked sheets and the amount of warpage deformation, FIG. 10 (a) is a characteristic diagram thereof, and FIG. 10 (b) is the warpage deformation thereof. It is a figure which shows a quantity.
[0042]
The sheet feeder of the present embodiment has a function of correcting a change in the amount of warpage deformation (S) due to a change in the number of stacked sheets in addition to the first and second embodiments.
Generally, at the start of printing, that is, when the number of stacked sheets is large, the amount of warpage deformation (S) is large, but the amount of sheet 9A decreases and the amount of warpage deformation (S) decreases with consumption. The amount of warpage (S) is not directly proportional to the number of stacked sheets 9A, but tends to decrease significantly as the number of sheets decreases, as shown in FIG.
[0043]
The paper feeder according to the present embodiment experimentally verifies the variation in the amount of warpage deformation (S) by associating the sheet thickness of the stacked sheets with the number of sheets, and obtains a predetermined functional expression (experimental expression) obtained by this. The height position of the uppermost seat surface is controlled to be corrected.
That is, as shown in FIG. 9, the present apparatus is added to the sheet feeding device configured as in the first and second embodiments, and furthermore, the warpage deformation (S) of the stacked sheets 9A and the number of stacked sheets Storage device 17 for storing an equation for calculating the correlation between the data, an input device 18 for inputting data affecting sheet supply, for example, a sheet thickness per sheet and the number of stacked sheets, and data in the storage device 17 described above. An arithmetic unit 10 for calculating the height correction amount of the upper surface sensor from the data of the input device 18; and a control unit 11 for controlling the height position of the upper surface sensor based on the calculation result of the arithmetic unit 10. Is done.
[0044]
In addition, the upper surface sensor elevating device 19 provided in the present device has a structure in which the amount of elevating and lowering can be set, and the height can be appropriately controlled via the control device 11.
Since the sheet feeding device according to the third embodiment of the present invention is configured as described above, for example, control is performed as follows.
Here, a case where the sheet pile 9 is warped upward as shown in FIGS. 4A to 4D will be described based on the first embodiment.
[0045]
First, the sheets 9A are stacked on the pallet as in the first embodiment, and then the pallet on which the sheet pile 9 is placed is placed on the sheet feeding table 5. Thereafter, the thickness per sheet and the total number of stacked sheets are input to the arithmetic unit 10, and a calculation formula (functional expression) is input to the arithmetic unit 10 via the storage device 17.
Subsequently, as in the first embodiment, initial settings for printing, that is, the height position of the uppermost sheet 9A are set by raising and lowering the sheet pile 9 and raising and lowering the upper surface sensor. As a result, the first upper surface sensor 12 is adjusted to the height at which the upper surface of the sheet pile 9 is detected, and the reference height position of the upper surface of the sheet pile 9 is set to the intermediate height of the warpage (S). . This initial setting is the same as that described in the first embodiment.
[0046]
After such setting, the height of the sheet is corrected and controlled based on the first upper surface sensor 12.
In the present embodiment, the position of the first upper surface sensor 12 is controlled to be corrected based on the amount of warpage deformation (S), the number of remaining sheets that have been consumed in printing, and the input calculation formula. As shown in FIG. 10, that is, since the amount of warpage deformation (S) decreases as the number of sheets decreases, the first upper surface sensor 12 is raised from the state shown in FIG. When the correction is completed, that is, in a state where the amount of warpage deformation (S) has been eliminated, the first upper surface sensor 12 has the same height as the second upper surface sensor 13.
[0047]
Next, the case where the sheet is warped as shown in FIGS. 5A to 5D will be described.
The initial height setting of the first upper surface sensor 12 and the sheet pile 9 at the time of starting printing is the same as in the case of the above-described warpage. As a result, the first upper surface sensor 12 is set to the height at which the upper surface of the uppermost sheet 9 is detected, and the reference height position of the uppermost sheet 9 of the sheet pile 9 is set to the intermediate height of the warpage (S). It will be. After such setting, the height position of the sheet to be supplied is corrected and controlled with reference to the first upper surface sensor 12.
[0048]
In the present embodiment, the first upper surface sensor 12 is lowered by a function as shown in FIG. 10, and when the correction is completed, the first upper surface sensor 12 and the second upper surface sensor 13 have the same height.
As described above, in the present embodiment, the top height of the stacking sheet (sheet pile) 9 is determined based on various conditions such as the amount of warpage deformation (S), the number of remaining sheets consumed in printing, and the input calculation formula. The upper surface sensor used as a reference at the time of control is corrected to the average height position of the warpage deformation (S), and can be similarly applied to the method (apparatus) of the second embodiment.
[0049]
The elevation drive of the sheet feeding table 5 accompanying the consumption of the sheet 9A and the configuration, functions and control of the related parts are the same as those in the first and second embodiments.
Since the present embodiment functions in this way, the following effects are obtained in addition to the effects of the first and second embodiments.
That is, the height position of the stacked uppermost sheet is detected, and the upper surface sensor serving as a reference for the elevation control is used to change the amount of warpage deformation (S) due to sheet consumption (reduction of the number of remaining sheets on the sheet feeding table). In conjunction with, the height of the topmost stacked sheet can be controlled with even higher precision in order to correct it so that it approaches the ideal height position, and the paper feeding state becomes stable and reliable .
[0050]
It should be noted that the present invention is not limited to the above-described embodiment, and can be carried out by variously modifying such an embodiment without departing from the spirit of the present invention. For example, the present paper feeding device may be applied outside of the sheet-fed printing press.
[0051]
【The invention's effect】
As described above in detail, according to the sheet feeding device of the present invention described in claim 1,Deformation such as undulation on the sheetOccursThe top shape of the sheet pile is deformedAlso,Control means,Multiple top sensorsThe upper surface shape of the sheet pile is grasped based on the detection signal fromSince the vertical position of the top sensor is corrected,By controlling the operation of the elevating mechanism based on the detection signal from this reference upper surface sensor,By properly adjusting the vertical position of the sheet, the sheet can be reliably fed to the next process.
[0052]
Also, multiple top sensorsAnySheet pile feeding directionInstalled on the sideBy doing the sheetofDeformation such as swellAgainstIt is possible to respond reliably (claim 2).
Furthermore, the top sensor is set to the sheet pile feeding direction.~ sideBy arranging them in the vicinity of the center in the left-right width direction and the end portions in the left-right width direction, it is possible to easily and surely cope with an upward curl or a downward curl which is a swell of the most common sheet. Item 3).
[0055]
By applying such a paper feeding device to a printing device of a sheet-fed printing press, it is possible to reduce paper feeding troubles, reduce waste paper, and improve the operation rate of the printing press, that is, productivity. The effect can be obtained.5).
[Brief description of the drawings]
FIG. 1 is an overall schematic configuration diagram of a sheet feeding device according to a first embodiment of the present invention.
FIGS. 2A and 2B are diagrams showing a main part of the sheet feeding device according to the first embodiment of the present invention, wherein FIG. 2A is a view in the direction of arrow A in FIG. 1 and FIG. is there.
FIGS. 3A and 3B are diagrams illustrating a sheet position detection system provided in the sheet feeding device according to the first embodiment of the present invention, wherein FIG. 3A is a diagram corresponding to FIG. 2A and FIG. It is a figure corresponding to (b).
FIG. 4 is a diagram for explaining the operation of the sheet feeding device according to the first embodiment of the present invention in the order of (a) to (d).
FIG. 5 is a diagram for explaining the operation of the sheet feeding device according to the first embodiment of the present invention in the order of (a) to (d).
6A and 6B are diagrams illustrating a sheet position detection system provided in a sheet feeding device according to a second embodiment of the present invention, wherein FIG. 6A is a diagram corresponding to FIG. 3A, and FIG. It is a figure corresponding to (b).
FIG. 7 is a diagram for explaining the operation of the sheet feeding device according to the second embodiment of the present invention in the order of (a) to (d).
FIG. 8 is a diagram for explaining the operation of the sheet feeding device according to the second embodiment of the present invention in the order of (a) to (d).
FIG. 9 is an overall schematic configuration diagram of a sheet position control system provided in a sheet feeding device according to a third embodiment of the present invention.
10A and 10B are diagrams showing a relative relationship between the number of stacked general stacked sheets and the amount of warpage deformation, wherein FIG. 10A is a characteristic diagram and FIG. 10B is a diagram showing the amount of warpage deformation.
FIG. 11 is an overall schematic configuration diagram of a sheet feeding device provided in a conventional sheet-fed printing press.
FIG. 12 is an explanatory diagram illustrating an example of a warped deformation state of a stacked sheet.
FIG. 13 is a schematic diagram for explaining a problem in a conventional sheet feeding device.
[Explanation of symbols]
1 Paper feeder (sheet feeder)
2 Suspension chains
3 Sprocket
4 Elevating drive motor
5 Paper feed table
8 Separator device
9 sheet pile
9A sheet
10 arithmetic unit
11 control device (control means)
12 First upper surface sensor
13 Second upper surface sensor
14 Sheet lifting device
14A seat lifting mechanism
15 Detector lifting device
16 feather boards
17 Storage device
18 Input device
19 Detector lifting device
20 feeder board
21 Vacuum suction pad
22 Feeding roller
(S) Warpage deformation
(V) Seat elevating speed
(T) Time difference of sensor operation

Claims (5)

A sheet feeder for feeding a sheet to a next process in order from an upper sheet of the sheet pile while adjusting a vertical position of a sheet pile formed by stacking a plurality of sheets,
An elevating mechanism for elevating the sheet pile,
An upper surface sensor disposed at each of a plurality of positions in the width direction of the sheet pile and detecting an upper surface of the sheet pile;
Control means for controlling the operation of the elevating mechanism based on a detection signal from a reference upper surface sensor, which is one of the plurality of upper surface sensors, and raising the sheet pile in response to consumption of the sheet. Sheet lifting device,
Sensor elevating means for moving vertically one or more including the upper surface sensor of at least the reference of the above SL plurality of top sensors is provided,
The control means grasps the top shape of the sheet pile based on detection signals from the plurality of top sensors prior to or at the time of the sheet feeding, and the sensor corresponds to the grasped top shape. A sheet feeding device configured to operate a lifting / lowering means to correct a vertical position of the reference upper surface sensor. 2. The sheet feeding device according to claim 1, wherein each of the plurality of upper surface sensors is provided on a sheet feeding direction side of the sheet pile. Upper level sensor, the left and right width direction central portion and left and right end portion in the width direction in the sheet feeding direction of the sheet pile, characterized in that it is arranged, respectively, according to claim 1 or 2, wherein the sheet feeding apparatus. The control means determines the amount of warpage generated in accordance with the warpage deformation of the upper surface of the sheet pile based on a detection signal from the plurality of upper surface sensors prior to or during the paper feeding. The height of the upper surface of the sheet pile is detected as a difference between the high position and the low position, and the vertical position of the reference upper surface sensor is set to an intermediate height between the high position and the low position of the upper surface position. The sheet feeding device according to any one of claims 1 to 3 , wherein the correction is performed in the following manner. The sheet is a sheet for printing, characterized in that the following steps are printing apparatus a sheet-fed printing press, the sheet feeding apparatus according to any one of claims 1-4.

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