JP2014101171A - Paper feeder including suction mechanism and paper feed control method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To feed accurately a corrugated cardboard sheet by regulating suction force of a suction mechanism acting on an arrangement region of partial upstream side paper feed rolls including a paper feed roll on the most upstream side in a paper feeding direction among a plurality of paper feed rolls.SOLUTION: A lifting member 19 brings a corrugated cardboard sheet into contact with a plurality of paper feed rolls 13A-13D upon descending, and separates the corrugated cardboard sheet from the plurality of paper feed rolls upon ascending. A suction mechanism 14 sucks the corrugated cardboard sheet downward in a region R1 where the plurality of paper feed rolls are arranged. A suction regulation mechanism 7 regulates suction force acting on the corrugated cardboard sheet in a region R2 where partial upstream side paper feed rolls including a paper feed roll on the most upstream side among the plurality of paper feed rolls are arranged. A paper feed control device 110 controls actuation and non-actuation of the suction regulation mechanism corresponding to the length of the corrugated cardboard sheet, when the order is changed.

Description

  In the present invention, in order to supply a cardboard sheet one by one to a processing apparatus that performs processing such as printing and grooving, a plurality of stacked cardboard sheets are sucked by a suction mechanism, and a plurality of the corrugated cardboard sheets are The present invention relates to a sheet feeding device that feeds out by a sheet feeding roll. Specifically, the present invention relates to a part of the upstream paper feed rolls including a paper feed roll whose rear end of the lowermost corrugated cardboard sheet is disposed on the most upstream side in the paper feed direction among the plurality of paper feed rolls. The present invention relates to a sheet feeding device that regulates the suction force of a suction mechanism that acts in the arrangement area when passing through the arrangement area.

  2. Description of the Related Art Conventionally, a sheet feeding device that feeds a lowermost sheet with a plurality of sheet feeding rolls while sucking a corrugated cardboard sheet with a suction mechanism is known as a rotary feeder. This type of paper feeding device feeds the lowermost corrugated cardboard sheet and the corrugated paper stacked above the lowermost corrugated cardboard sheet when the front end of the lowermost corrugated cardboard sheet passes through the front gate and is conveyed for a predetermined distance. A lifting member called a great is provided. The elevating member is configured to be movable up and down with respect to the paper feed roll, and the elevating operation is performed in synchronization with the paper feed operation of the paper feed roll.

  As an example of a paper feeding device provided with an elevating member, a paper feeding device described in Patent Document 1 has been proposed. In the paper feeding device described in Patent Document 1, four paper feeding rolls are arranged in the paper feeding direction. When the rear end of the lowermost corrugated cardboard sheet is no longer in contact with the two paper feed rolls arranged on the upstream side in the paper feed direction, the rotation of the two paper feed rolls stops sequentially or simultaneously. By stopping the rotation of the paper feed roll, even if the second corrugated cardboard sheet from the lowest layer is sucked by the suction mechanism and comes into contact with the two upstream paper feed rolls, the second corrugated cardboard sheet is separated from the paper feed roll. It can be prevented from being damaged by friction.

JP 2009-120400 A

  The paper feeding device described in Patent Document 1 is effective in that the second corrugated cardboard sheet from the bottom layer can be prevented from being damaged by friction with the paper feeding roll. However, the paper feeding device described in Patent Document 1 still has the following problems. That is, when the rear end of the lowermost corrugated cardboard sheet is not in contact with the two paper feed rolls arranged upstream in the paper feeding direction, the second corrugated cardboard sheet is sucked downward by the suction mechanism and fed. The lowermost corrugated cardboard sheet is sandwiched between the paper supply table of the paper device. This pinching force acts due to the suction force of the suction mechanism, and causes frictional resistance between the upper surface of the lowermost corrugated cardboard sheet and the lower surface of the second corrugated cardboard sheet. Due to this frictional resistance, there is a problem that the lowermost corrugated cardboard sheet cannot be fed accurately.

  In order to reduce the frictional resistance, it is conceivable to reduce the suction force of the suction mechanism. When the suction force is reduced, the contact resistance between the two paper feed rolls arranged downstream in the paper feed direction and the lower surface of the lowermost corrugated cardboard sheet is reduced, and the two paper feed rolls are the lowermost corrugated cardboard sheets. The conveying force applied to the lower surface of the sheet is also reduced. Due to the reduced conveyance force, there is a problem that the lowermost corrugated cardboard sheet cannot be fed with high accuracy.

  Therefore, the present invention has been made in view of the above problems, and among the plurality of paper feed rolls, the arrangement of some upstream paper feed rolls including the paper feed roll that is most upstream in the paper feed direction. It is an object of the present invention to provide a paper feeding device capable of feeding a corrugated cardboard sheet accurately by regulating the suction force of the suction mechanism acting on the area.

(First Invention Aspect and its Specific Aspect)
In order to achieve the above object, according to a first aspect of the present invention, a lowermost corrugated cardboard sheet among a plurality of laminated corrugated cardboard sheets is fed in a paper feeding direction toward a downstream processing apparatus. In the sheet feeding device, a plurality of sheet feeding rolls arranged in the sheet feeding direction and in contact with the lower surface of the cardboard sheet and configured to be movable up and down with respect to the plurality of sheet feeding rolls. A lifting member that pulls the cardboard sheet away from the plurality of paper feed rolls when brought into contact with the paper feed roll, a suction mechanism that sucks the cardboard sheets downward in an area where the plurality of paper feed rolls are disposed, and a plurality of Of the paper feed rolls in the area where some upstream paper feed rolls including the most upstream paper feed roll in the paper feed direction are arranged. A suction restricting means for restricting the suction force of the suction mechanism, and a controller for controlling the operation and non-operation of the suction restricting means according to the length of the corrugated cardboard sheet in the paper feeding direction when the order is changed, Is provided.

  In the first aspect of the present invention, the region in which a part of the upstream-side sheet feed rolls including the most upstream sheet-feed roll in the sheet-feeding direction among the plurality of sheet-feed rolls is disposed is the most upstream sheet-feed roll. It may be an area where only rolls are arranged, or an area where half or nearly half of the plurality of paper feeding rolls existing on the upstream side are arranged. For example, when five paper feed rolls are arranged, as some upstream paper feed rolls, the most upstream paper feed roll, two upstream paper feed rolls, or three upstream paper feed rolls Applicable role.

  In the first aspect of the invention, the suction restricting means acts on the cardboard sheet even in a configuration in which the suction force of the suction mechanism is stopped from acting on the cardboard sheet in a region where some of the upstream-side paper feed rolls are arranged. The structure which reduces attraction | suction force may be sufficient. The suction restricting means may be configured to restrict the operation of the suction mechanism itself, or may be configured to restrict the suction force acting on the corrugated cardboard sheet with the shielding member in a state where the suction mechanism is always operated.

  In the first aspect of the invention, a part of the upstream-side paper feed rolls may be configured to be rotationally driven while the suction restricting unit is operating, or may be configured not to be provided with the rotational driving force.

  In the first aspect of the invention, the elevating member is driven by a single drive motor common to the plurality of paper feed rolls, even if the lift member is driven by an individual drive motor in synchronization with the rotation of the plurality of paper feed rolls. But you can.

  In the first aspect of the invention, the length of the corrugated cardboard sheet may be a configuration instructed from the production management device, a configuration input by an operator from an operation panel, or a configuration detected by a detection means.

  In the first aspect of the invention, the control unit may be configured to control the operation and non-operation of the suction restricting unit according to the length of the corrugated cardboard sheet and other factors related to the sheet feeding accuracy. For example, the distance from the front end of the cardboard sheet to the formation position of the ruled line is considered as another factor.

  According to a specific aspect of the present invention, the control unit includes an adjustment mechanism that adjusts a lowering timing for lowering the elevating member and an elevating timing for raising the elevating member in a paper feeding period for feeding one cardboard sheet. When the suction restricting means is operated, the adjustment mechanism is controlled so that the rising timing is delayed according to the distance in the paper feeding direction of the region where some upstream paper feeding rolls are arranged.

  In a specific aspect, the control unit is configured to control the adjustment mechanism so that the delay time of the rising timing becomes longer as the distance in the paper feeding direction of the region in which some upstream paper feeding rolls are arranged becomes longer. If it is.

  According to a specific aspect of the present invention, when the length of the corrugated cardboard sheet in the paper feeding direction is equal to or less than a predetermined sheet length, the control unit operates the suction restricting means to corrugate the paper cardboard in the paper feeding direction. When the length of the sheet exceeds a predetermined sheet length, the suction regulating unit is deactivated.

  In a specific aspect, the predetermined sheet length is changed depending on factors such as the mechanical dimension of the sheet feeding device in the sheet feeding direction and the distance from the leading end of the corrugated sheet to the formation position of the ruled line. In consideration of the damage of the corrugated cardboard sheet due to the friction and the sheet feeding accuracy of the corrugated cardboard sheet, it is predetermined through experimental results.

  According to a specific aspect of the present invention, the apparatus includes a pair of feed rolls arranged downstream of the plurality of paper feed rolls in the paper feed direction, sandwiching the corrugated cardboard sheet and feeding it toward the downstream processing apparatus, The determined sheet length is determined based on the distance in the sheet feeding direction between the rotation center of the most upstream sheet feeding roll and the rotation center of the pair of feed rolls.

  In a specific aspect, the predetermined sheet length is determined based on the distance in the sheet feeding direction between the rotation center of the most upstream sheet feeding roll and the rotation center of the pair of feed rolls as one of the main factors. However, it may be determined in consideration of factors other than this distance.

  In a specific aspect, when the sheet feeding device includes a plurality of pairs of feed rolls in the sheet feeding direction, the predetermined sheet length is determined by the rotation center of the most upstream sheet feeding roll and the plurality of feeding rolls. It is determined based on the distance in the paper feeding direction between the rotation centers of the pair of feed rolls arranged at positions closest to the paper roll.

  According to a specific aspect of the present invention, a rotation driving unit that applies a rotational driving force to a plurality of paper feed rolls, and a rotational driving force is applied to some upstream paper feeding rolls among the plurality of paper feeding rolls. Stopping means for stopping the operation, and when the length of the corrugated cardboard sheet in the sheet feeding direction is equal to or less than a predetermined sheet length, the stopping means is driven to rotate to some upstream sheet feeding rolls. When the corrugated sheet length in the paper feeding direction exceeds a predetermined sheet length, a rotational driving force is allowed to be applied to some upstream paper feed rolls. .

  In a specific aspect, the plurality of paper feed rolls may be configured to receive a rotational driving force from a single drive motor via a power transmission cutoff mechanism, or may be configured to apply a rotational driving force from each of the plurality of drive motors. . The stop means is configured to stop a part of the plurality of drive motors even in a configuration in which the power transmission cutoff mechanism is operated in a cutoff state in order to stop applying the rotational driving force to some of the upstream side paper supply rolls. But you can.

  According to a specific aspect of the present invention, the stopping means stops the application of the rotational driving force to some upstream paper feed rolls, and the rotational driving force to some upstream paper feed rolls. Including a clutch mechanism configured to be switchable between a connection position that allows application of the

  According to a specific aspect of the present invention, the suction regulating means includes a cover member that covers at least the most upstream paper feed roll among some of the upstream paper feed rolls, and the cover member is a raised / lowered member It is configured to be movable between an operating position that covers at least the most upstream paper feed roll at a higher position and an inoperative position that is retracted from some upstream paper feed rolls.

  In a specific aspect, when the suction restricting means is located at the operating position, the cover member may be configured to cover only the most upstream sheet feed roll, or may cover all of some of the upstream sheet feed rolls.

  According to a specific aspect of the present invention, the suction mechanism includes a suction chamber that houses a plurality of paper feed rolls, and a suction port that is formed in the suction chamber to suck air in the suction chamber. The means includes a separation wall that separates the suction chamber into a first space that is isolated from the suction port and a second space that communicates with the suction port, and at least the most upstream of some of the upstream paper feed rolls The sheet feed roll is disposed in the first space, and the separation wall separates the first space from the second space, which is another space inside the suction chamber other than the first space, and the first space. And it is comprised so that it can move between the non-operating positions which connect 2nd space.

  In a specific aspect, only the most upstream sheet feed roll may be arranged in the first space, or a part of all the upstream sheet feed rolls may be arranged in the first space.

(Second Invention Aspect and its Specific Aspect)
In order to achieve the above object, a second aspect of the present invention according to claim 9 is a suction mechanism for sucking a plurality of stacked cardboard sheets downward, and a plurality of paper feed rolls arranged in a paper feed direction. A sheet feeding device that feeds in a sheet feeding direction toward a downstream processing device by a plurality of sheet feeding rolls while sucking a lowermost one of the plurality of stacked cardboard sheets. Among the paper rolls, in the area where some upstream paper feed rolls including the most upstream paper feed roll in the paper feed direction are arranged, the corrugated cardboard sheet is changed according to the length of the cardboard sheet in the paper feed direction. This is a paper feed control method for controlling the action of the suction force of the suction mechanism and the restriction of the suction force.

  In the second aspect of the invention, the area where a part of the upstream paper feed rolls is arranged is interpreted in the same manner as in the first aspect of the invention. Further, in the second aspect of the invention, the state in which the suction force of the suction mechanism with respect to the cardboard sheet is regulated is reduced even when the suction force of the suction mechanism is stopped from acting on the cardboard sheet. It may be in a state to be allowed.

  According to a specific aspect of the present invention, when the length of the corrugated cardboard sheet in the paper feeding direction exceeds a predetermined sheet length, the suction of the suction mechanism is performed in all the areas where the plurality of paper feeding rolls are arranged. A step of applying a force to the corrugated cardboard sheet, and when the length of the corrugated cardboard sheet in the paper feeding direction is equal to or less than a predetermined sheet length, among the plurality of paper feeding rolls, Regulating the suction force of the suction mechanism acting on the corrugated cardboard sheet in a region where a part of the upstream paper feed roll including the paper roll is disposed.

  In a specific aspect, the predetermined sheet length is interpreted in the same manner as the specific aspect of the first invention aspect.

(Effects of the first and second aspects of the invention)
In the first or second aspect of the invention, in the region where some upstream paper feed rolls are arranged, the action of the suction force of the suction mechanism on the cardboard sheet and the regulation of the suction force are corrugated in the paper feed direction. It is controlled according to the length of the sheet. As a result, the cardboard sheet can be accurately fed regardless of the length of the cardboard sheet in the paper feeding direction.

(Effects of specific aspects)
According to a specific aspect of the present invention, when the suction restricting unit is operated during the sheet feeding period, the rising timing is determined according to the distance in the sheet feeding direction of the area where some upstream sheet feeding rolls are arranged. The adjustment mechanism is controlled so as to delay. As a result, by restricting the suction force of the suction mechanism, it is possible to prevent the second corrugated cardboard sheet from the lowermost layer from being damaged and to accurately feed the lowermost corrugated cardboard sheet.

  According to a specific aspect of the present invention, when the length of the corrugated cardboard sheet in the paper feeding direction is equal to or less than a predetermined sheet length, the suction force is restricted, and the length of the corrugated cardboard sheet in the paper feeding direction is When the predetermined sheet length is exceeded, a suction force acts. As a result, even when the length of the corrugated cardboard sheet is equal to or shorter than a predetermined sheet length, the second corrugated cardboard sheet from the lowermost layer is prevented from being damaged, and the lowermost corrugated cardboard sheet is fed accurately. Can do.

  According to a specific aspect of the present invention, the predetermined sheet length is based on a distance in the sheet feeding direction between the rotation center of the most upstream sheet feeding roll and the rotation center of the pair of feed rolls. It is determined. The predetermined sheet length is a sheet length in which the leading end of the corrugated cardboard sheet is positioned at the nip position of the pair of feed rolls, and the trailing end can contact the most upstream sheet feeding roll. As a result, when the length of the corrugated cardboard sheet is equal to or less than a predetermined sheet length, the suction force is regulated by the operation of the suction regulating means, so that the second corrugated cardboard sheet from the bottom layer is surely damaged. And the lowermost corrugated cardboard sheet can be fed accurately.

  In the specific aspect of claim 5, when the length of the corrugated cardboard sheet is equal to or shorter than a predetermined sheet length, the application of the rotational driving force to a part of the upstream paper feed rolls is stopped. When the length of the corrugated cardboard sheet exceeds a predetermined sheet length, it is allowed to apply a rotational driving force to a part of the upstream paper feed rolls. As a result, since the application of the rotational driving force to some of the upstream paper feed rolls is stopped, the rotation of some of the upstream paper feed rolls is disposed near the paper feed rolls, Or it can prevent reliably interfering with a cardboard sheet.

  According to a specific aspect of the present invention, the clutch mechanism of the stop means stops applying the rotational driving force to a part of the upstream paper feed rolls at the shut-off position, and a part of the upstream at the connection position. It is allowed to apply a rotational driving force to the side paper feed roll. As a result, some upstream-side paper feed rolls can rotate at the clutch mechanism disengagement position, so that some upstream-side paper feed rolls move the members arranged close to the paper feed rolls. It is possible to reliably prevent resistance or damage to the cardboard sheet.

  According to a specific aspect of the present invention, the cover member of the suction restricting means covers at least the most upstream paper feed roll at a position above the raised lift member at the operating position, and partially at the non-operating position. Evacuates from the upstream side paper feed roll. As a result, since the cover member covers at least the most upstream sheet feeding roll, the second corrugated cardboard sheet from the lowermost layer can be reliably prevented from being damaged, and the lowermost corrugated cardboard sheet can be fed accurately. .

  According to a specific aspect of the present invention, at least the most upstream sheet feed roll among the some upstream sheet feed rolls is disposed in the first space. The separation wall of the suction restricting means separates the first space and the second space, which is another space inside the suction chamber other than the first space, in the operating position, and in the inoperative position, the first space and The second space is communicated. As a result, since the first space and the second space are separated by the separation wall, the second corrugated cardboard sheet from the lowermost layer is reliably prevented from being damaged, and the lowermost corrugated cardboard sheet is fed accurately. Can do.

  According to a specific aspect of the present invention, when the length of the corrugated cardboard sheet in the sheet feeding direction exceeds a predetermined sheet length, suction of the suction mechanism is performed in all the areas where the plurality of sheet feeding rolls are arranged. The force acts on the cardboard sheet. Further, when the length of the corrugated cardboard sheet in the sheet feeding direction is equal to or less than a predetermined sheet length, a part of the plurality of sheet feeding rolls including the most upstream sheet feeding roll in the sheet feeding direction The suction force of the suction mechanism acting on the corrugated cardboard sheet is restricted in the area where the side paper feed roll is disposed. As a result, even when the length of the corrugated cardboard sheet is equal to or shorter than a predetermined sheet length, the second corrugated cardboard sheet from the lowermost layer is prevented from being damaged, and the lowermost corrugated cardboard sheet is fed accurately. Can do.

It is a front view showing a part of corrugated board box making machine 1 concerning a 1st embodiment of the present invention. It is a front view which expands and shows the paper feed mechanism 4 of the corrugated board box making machine 1. FIG. 4 is a plan view of the inside of the paper feed mechanism 4 as viewed from above. It is the side view which looked at the inside of coupling mechanism 34 from the right. FIG. 4 is a partial cross-sectional view of the inside of the cam adjustment mechanism 22 as viewed from the right side. 2 is a block diagram mainly showing an electrical configuration of a paper feeding unit 2. FIG. 6 is a flowchart illustrating a paper feed control process. It is drawing which shows the paper supply state of comparatively long corrugated cardboard sheet SH. It is drawing which shows the paper supply state of relatively short corrugated cardboard sheet SH. It is a drawing showing a relatively short cardboard sheet SH feeding state when it is assumed that the process of S6 is executed instead of the process of S9 and the ascending timing of the great 19 is not delayed. 10 is a timing chart showing the relationship between the peripheral speed of the sheet feeding rolls 13A to 13D, the lifting distance of the great 19, the sheet feeding distance of the cardboard sheet SH, and the rotation angle of the drive shaft 23. It is a front view which expands and shows the paper feed mechanism 4 of the cardboard sheet box making machine 1 according to the second embodiment of the present invention.

[First embodiment]
A first embodiment in which the paper feeding device of the present invention is applied to a corrugated board box making machine will be described below with reference to the accompanying drawings. A corrugated sheet box making machine is a machine that sequentially performs a plurality of processes such as printing, vertical ruled lines, grooving and punching on a corrugated sheet fed from a sheet feeding device, and is known from Japanese Patent Application Laid-Open No. 2003-1727. It is. Since the overall configuration of the corrugated cardboard box making machine is known, a paper feeding unit particularly related to the paper feeding device of the present invention and a printing unit arranged downstream thereof will be described. The description of the die cutter unit is omitted. In the drawings, a vertical direction, a horizontal direction, and a front-rear direction are determined according to directions indicated by arrows.

<< Partial configuration of corrugated cardboard box making machine 1 >>
FIG. 1 is a front view showing the configuration of a paper feeding unit 2 and a printing unit 3 of a corrugated cardboard box making machine 1 according to the present embodiment. In FIG. 1, the paper feed unit 2 mainly includes a paper feed mechanism 4, first feed rolls 5 </ b> A and 5 </ b> B, second feed rolls 6 </ b> A and 6 </ b> B, and a suction restriction mechanism 7. The printing unit 3 mainly includes a printing cylinder 8 and a press roll 9. The corrugated cardboard box making machine 1 includes a main drive motor MT for driving each unit synchronously.

<Configuration of paper feed unit 2>
The sheet feeding unit 2 conveys the corrugated cardboard sheets SH fed one by one from the sheet feeding mechanism 4 while being sequentially sandwiched by the first feed rolls 5A and 5B and the second feed rolls 6A and 6B, and the printing unit. Send to 3. The first feed rolls 5A and 5B are arranged downstream of the paper feeding mechanism 4 in the paper feeding direction DF of the corrugated cardboard sheet SH. The second feed rolls 6A and 6B are disposed downstream of the first feed rolls 5A and 5B in the paper feeding direction DF. Each of the first and second feed rolls is a roll having the same diameter, and is connected to and driven by the main drive motor MT.

(Detailed configuration of paper feed mechanism 4)
The configuration of the paper feed mechanism 4 will be described with reference to FIGS. FIG. 2 is an enlarged front view showing the sheet feeding mechanism 4 with the suction mechanism 14 omitted. In FIG. 2, the paper feed mechanism 4 includes a front gate 11 and a back guide 12 above the paper feed table 10. The front gate 11 is arranged at a fixed position in the paper feeding direction DF. The front gate 11 is in contact with the front ends of a number of stacked cardboard sheets, that is, the left end of the cardboard sheets in FIG. The back guide 12 is disposed so as to be movable in the left-right direction with respect to the front gate 11 in accordance with the length of the corrugated cardboard sheet in the sheet feeding direction DF. The back guide 12 contacts the rear end of the cardboard sheet, that is, the right end of the cardboard sheet in FIG. 2, and aligns the position of the rear end of the cardboard sheet.

  1 and 2, the paper feed mechanism 4 includes four rows of paper feed rolls 13 </ b> A to 13 </ b> D, a suction mechanism 14, and an elevating mechanism 15 below the paper feed table 10. The paper feed rolls 13A to 13D are arranged at an interval in the paper feed direction DF.

  The suction mechanism 14 sucks the stacked cardboard sheets downward. The suction mechanism 14 includes a suction chamber 16, a duct 17, and a blower motor 18. The suction chamber 16 is formed in a size that accommodates all of a large number of paper feed rolls disposed below the paper feed table 10. The duct 17 connects the suction port 16 </ b> A formed at the bottom of the suction chamber 16 and the blower motor 18. The blower motor 18 is composed of an induction motor, and rotates at a speed corresponding to the frequency of the drive signal. As the rotational speed of the blower motor 18 increases, a larger negative pressure is generated in the suction chamber 16. Due to the large negative pressure, the corrugated cardboard sheets to be stacked are sucked toward the sheet feeding rolls 13A to 13D with a large suction force.

  In FIG. 2, the elevating mechanism 15 includes a great 19, a coupling mechanism 20, a drive mechanism 21, and a cam adjusting mechanism 22 shown in FIG. The great 19 includes a receiving plate 19A and a pair of support legs 19B and 19C. The receiving plate 19A is arranged in the same area as the arrangement area R1 of the sheet feeding rolls 13A to 13D in the sheet feeding direction DF, and can contact the cardboard sheet SH from below. The lower ends of the pair of support legs 19B and 19C are coupled to the pair of lock arms 20A and 20B of the coupling mechanism 20, respectively. The connection mechanism 20 has a connection arm 20C fixed to the rotation shaft of the lock arm 20A.

  The drive mechanism 21 includes a drive shaft 23, a first cam 24A, a second cam 24BB, and a rocking body 25. The drive shaft 23 is connected to the main drive motor MT via a known power transmission mechanism. The first cam 24 </ b> A is a cam that controls the descending timing of the great 19 and is fixed to the drive shaft 23. The second cam 24BB is a cam that controls the ascent timing of the great 19, and is rotatably attached to the drive shaft 23 so that the rotational phase is adjusted with respect to the first cam 24A. The swing body 25 is attached so as to be swingable about a swing shaft 26 fixed to the frame of the paper feeding mechanism 4. The rocking body 25 has an arm 27. The cam follower 28 is rotatably supported at the tip of the arm 27, and the lower end portion of the connecting arm 20 </ b> C is connected to the tip of the arm 27. When the cam follower 28 engages with the high cam surface of the second cam 24BA, the great 19 rises above the paper feed rolls 13A to 13D and pulls the cardboard sheet SH away from the paper feed rolls 13A to 13D. When the cam follower 28 engages with the lower cam surface of the first cam 24A, the great 19 descends below the upper surface of the paper feed rolls 13A to 13D, and brings the corrugated cardboard sheet SH into contact with the paper feed rolls 13A to 13D. The basic structures of the coupling mechanism 20 and the drive mechanism 21 in the lifting mechanism 15 are known from US Pat. No. 5,184,811 and drawings.

  A drive gear 29 is fixed to the drive shaft 23 and is connected to the main drive motor MT via a speed reduction mechanism. The drive shaft 23 rotates only once in the arrow direction CD shown in FIG. 2 while the sheet feeding mechanism 4 feeds one cardboard sheet SH. As the drive shaft 23 rotates, the first and second cams 24BA and 24B rotate only once while the sheet feeding mechanism 4 feeds one cardboard sheet SH.

  FIG. 3 is a plan view of the inside of the paper feed mechanism 4 as viewed from above with the paper feed table 10 removed. In FIG. 3, a large number of paper feed rolls are fixed to the rotary shafts of four rotary shafts 30 </ b> A to 30 </ b> D extending in a direction orthogonal to the paper feed direction DF. The inter-axis distances, which are the intervals between the rotation centers of two adjacent rotation shafts among the rotation shafts 30A to 30D, are all set to be the same. The rotary shafts 30 </ b> A to 30 </ b> D are connected to the drive gear 29 via the transmission unit 31. The transmission unit 31 mainly includes a speed increasing mechanism 32, connecting members 33A to 33C, and a coupling mechanism 34. The speed increasing mechanism 32 speeds up the rotation of the drive gear 29 and transmits it to the four output shafts 35A to 35D. The connecting members 33A to 33C connect the output shafts 35A to 35C with the rotating shafts 30A to 30C, respectively. The coupling mechanism 34 transmits the rotation of the output shaft 35D to the rotation shaft 30D or interrupts the transmission of the rotation. The speed increasing mechanism 32 includes a Geneva gear and a planetary gear. The structure of the speed increasing mechanism 32 is known from US Pat. No. 5,184,811 and drawings. With this speed increasing mechanism, the peripheral speeds of the paper feed rolls 13A to 13D are changed from the rotation stopped state to the first feed roll 5A, during the paper feeding operation of one cardboard sheet, as shown in FIG. The speed is increased to a predetermined peripheral speed of 5B, maintained at the predetermined peripheral speed, and then decelerated from the predetermined peripheral speed to the rotation stopped state. At the start time TS of the paper feed operation, which is the time point when the great 19 is lowered below the upper surfaces of the paper feed rolls 13A to 13D, the peripheral speeds of the paper feed rolls 13A to 13D are substantially in a rotation stopped state.

(Detailed configuration of coupling mechanism 34)
The configuration of the coupling mechanism 34 will be described with reference to FIGS. 3 and 4. FIG. 4 is a side view of the inside of the coupling mechanism 34 as viewed from the right. In FIG. 4, the coupling mechanism 34 includes a pair of clutch members 36 and 37, a spline shaft body 38, and an operation mechanism 39. The clutch member 36 is fixed to the output shaft 35D and has a clutch pawl 36A. The clutch member 37 includes a clutch pawl 37A that can be engaged with the clutch pawl 36A, and a coupling recess 37B. The spline shaft body 38 is connected to the rotary shaft 30D via a connecting member, and has a spline shaft portion 38A. The clutch member 37 has a spline nut portion that meshes with the spline shaft portion 38A. The clutch member 37 can slide in the front-rear direction on the spline shaft body 38 in FIG. 4 and can rotate together with the spline shaft body 38 by meshing between the spline shaft portion 38A and the spline nut portion.

  The operating mechanism 39 includes an air cylinder 40 and a connecting member 41. The air cylinder 40 is fixed to the frame of the paper feed mechanism 4 and has an operating rod 40A. The connecting member 41 is fixed to the tip of the operating rod 40A and has a bifurcated connecting piece 41A. The bifurcated connecting piece 41 </ b> A engages with the connecting recess 37 </ b> B of the clutch member 37. FIG. 4 shows a state where the operating rod 40A protrudes forward, the clutch claws 36A and 37A are engaged, and the output shaft 35D and the rotary shaft 30D are connected. When the operating rod 40A is retracted rearward, the clutch pawl 37A is separated from the clutch pawl 36A, and the connection between the output shaft 35D and the rotary shaft 30D is cut off.

(Detailed configuration of cam adjustment mechanism 22)
The configuration of the cam adjustment mechanism 22 will be described with reference to FIG. FIG. 5 is a partial cross-sectional view of the inside of the cam adjustment mechanism 22 as viewed from the right side. In FIG. 5, the cam adjusting mechanism 22 is a mechanism for adjusting the rotational phase of the second cam 24B relative to the first cam 24A, and mainly includes a wave gear mechanism 42 and a servo motor 43. The servo motor 43 is fixed to the frame of the paper feed mechanism 4.

  The wave gear mechanism 42 includes first and second circular splines 44 and 45, a flex spline 46, and a wave generator 47. The wave generator 47 is fixed to the adjustment input shaft 48. The adjustment input shaft 48 is rotatably attached to the frame of the paper feed mechanism 4 and is connected to the output shaft of the servo motor 43 via gears 49 and 50. The first circular spline 44 is connected to the gear 52 via the first rotary connecting body 51. The first rotary coupling body 51 is rotatably mounted on the adjustment input shaft 48. The gear 53 is fixed to the drive shaft 23 and meshes with the gear 52. The second circular spline 45 is connected to the gear 55 via the second rotary connecting body 54. The second rotary coupling body 54 is rotatably mounted on a support shaft 56 fixed to the frame of the paper feed mechanism 4. The gear 57 is fixed to the second cam 24 </ b> B and meshes with the gear 55. The first circular spline 44 has the same number of teeth as the flexspline 46, but the second circular spline 45 has a different number of teeth than the flexspline 46. As a result, the first circular spline 44 does not rotate relative to the flexspline 46, but the second circular spline 45 rotates relative to the flexspline 46. When the wave generator 47 is rotated by the rotation of the servo motor 43 in a state where the drive shaft 23 is stopped, the second circular spline 45 rotates relative to the first circular spline 44. The cam 24 </ b> B rotates according to the rotation amount of the servo motor 43, and changes the rotation phase with respect to the first cam 24 </ b> A fixed to the drive shaft 23. The basic configuration of the wave gear mechanism 42 is known from Japanese Patent No. 2718540.

(Detailed structure of the suction restriction mechanism 7)
The configuration of the suction restriction mechanism 7 will be described with reference to FIGS. The suction restriction mechanism 7 is a mechanism for restricting the suction force of the suction mechanism 14 acting on the cardboard sheet, and mainly includes a cover member 58, a guide mechanism 59, and an air cylinder 60. In FIG. 2, the cover member 58 is disposed in a space between the lower end of the back guide 12 and the upper surface of the paper feed table 10, and close to the upper surface of the paper feed table 10 and the upper surface of the paper feed roll 13 </ b> D. To position. The cover member 58 extends along the upper surface of the sheet feed table 10 in the left-right direction as shown in FIG. 2 and in the front-rear direction as shown in FIG. The cover member 58 has a bent portion 58A at the right end thereof. The guide mechanism 59 is a mechanism that guides the cover member 58 in the left-right direction along the upper surface of the paper feed table 10, and is disposed on the right wall of the suction chamber 16.

  In FIG. 3, the guide mechanism 59 mainly includes a moving body 61 and a pair of guide shafts 62 and 63. Both guide shafts 62 and 63 are fixed to the right wall of the suction chamber 16 and extend in the left-right direction from the wall. The moving body 61 is guided by both guide shafts 62 and 63 and is arranged so as to be movable in the left-right direction. In FIG. 2, the moving body 61 has a bent portion 61A at the left end. The bent portion 61 </ b> A of the moving body 61 is fixed to the bent portion 58 </ b> A of the cover member 58.

  The air cylinder 60 is disposed on the right wall of the suction chamber 16 and has an operating rod 60A. The distal end of the operating rod 60A is connected to the bent portion 61A of the moving body 61. As a result, when the operating rod 60A protrudes as shown in FIG. 2, the cover member 58 is in an operating position that covers a partial region R2 of the arrangement region R1 of the paper feed rolls 13A to 13D as shown by a solid line in FIG. When the operating rod 60A is retracted, the cover member 58 is positioned at the inoperative position retracted from the arrangement region R1 of the paper feed rolls 13A to 13D as indicated by a two-dot chain line in FIG.

  In FIG. 2, when the cover member 58 is located at the operating position, in the present embodiment, the cover member 58 is the paper feed roll 13D that is disposed on the most upstream side in the paper feed direction DF among the paper feed rolls 13A to 13D. Cover the placement area. The arrangement area of the paper feed roll 13D will be specifically described. In FIG. 2, an area R1 indicates an arrangement area of the paper feed rolls 13A to 13D in the paper feed direction DF, and is an area from the left end of the paper feed roll 13A to the right end of the paper feed roll 13D. An area R2 indicates an area covered by the cover member 58 among the arrangement areas of the paper feed rolls 13A to 13D. The position PC indicates a position on an extension line in the vertical direction passing through the rotation center of the rotation shaft 30C of the paper feed roll 13C, and the position PD is on an extension line in the vertical direction passing through the rotation center of the rotation shaft 30D of the paper feed roll 13D. Indicates the position. Further, the position PC and the position PD may be considered to indicate positions on an extension line in the vertical direction passing through a contact point where the paper feed rolls 13C and 13D are in contact with the lower surface of the cardboard sheet SH. In the present embodiment, the left end of the region R2 is located at the center position between the position PC and the position PD. An area R2 is an area from the center position to the right end of the paper feed roll 13D, and corresponds to an arrangement area of the paper feed roll 13D. In the present embodiment, the region R2 is set to be the same as the distance between the rotation axes of adjacent paper feed rolls.

<Configuration of printing unit 3>
The printing unit 3 performs printing on a predetermined position of the cardboard sheet SH sent out from the second feed rolls 6A and 6B. During the printing operation, the printing cylinder 8 and the press roll 9 convey the cardboard sheet. The printing cylinder 8 and the press roll 9 are connected via a speed reduction mechanism so that the peripheral speeds of the printing cylinder 8 and the press roll 9 are the same as the peripheral speeds of the first and second feed rolls 5A, 5B, 6A, 6B. Connected to the main drive motor MT. The printing cylinder 8 rotates only once while the paper feeding mechanism 4 feeds one cardboard sheet SH.

<Configuration of various detectors>
An origin detector HD is provided to detect when the sheet feeding operation of the lowermost corrugated cardboard sheet to be laminated starts. The origin detector HD is composed of a known proximity sensor including a detection coil and an oscillation circuit. When the metal piece 64 attached to the side surface of the drive gear 29 approaches the high frequency magnetic field generated by the detection coil of the origin detector HD, the origin detector HD is oscillated by the current induced in the metal piece 64. Stops oscillation and generates a detection signal.

  A pulse generator PG1 is attached to the output shaft of the main drive motor MT in order to measure the transport amount of the corrugated board sheet SH in the paper feeding direction DF. The pulse generator PG1 generates a number of pulses corresponding to the amount of rotation of the output shaft of the main drive motor MT.

  A pulse generator PG <b> 2 is connected to the output shaft of the servo motor 43 in order to measure the rotation amount and rotation direction of the servo motor 43. The pulse generator PG2 generates pulses having a number and phase corresponding to the rotation amount and rotation direction of the output shaft of the servo motor 43.

<Electrical configuration>
With reference to FIG. 6, the electrical configuration of the sheet feeding unit 2 in the first embodiment will be mainly described. FIG. 6 is a block diagram illustrating an electrical configuration of the sheet feeding unit 2. In FIG. 6, the management apparatus 100 manages the entire operation of the corrugated board box making machine 1 in order to sequentially execute a plurality of consecutive orders. The paper feed control device 110 is provided to control the paper feed operation of the paper feed unit 2. The paper feed control device 110 receives a command including information such as a sheet length and a conveyance speed determined for executing each order from the management device 100, performs a control operation in accordance with the command, and displays a current control state. Notify the management device 100. Similar to the paper feed control device 110, the other processing control device 120 is also provided to control the processing operation of other processing units such as the printing unit 3, and performs control operations in accordance with commands from the management device 100. The management apparatus 100 is notified of the current control state. The motor control device 130 controls the rotation and stop of the main drive motor MT, and controls the rotation speed of the main drive motor MT according to a command from the management device 100. Further, the motor control device 130 counts the number of pulses generated from the pulse generator PG1 as the main drive motor MT rotates, and notifies the management device 100 of the counted number of pulses.

  The program memory 140 fixedly stores a control program such as a paper feed control program and various setting values. The paper feed control program is a program for executing the paper feed control process shown in FIG. The various set values are a threshold value LS relating to the sheet length in the sheet feeding direction DF, an initial set value of the frequency of the drive signal of the blower motor 18, and the like. The work memory 141 temporarily stores instructions and information supplied from the management apparatus 100 and temporarily stores processing results that are arithmetically processed by execution of the paper feed control program. The threshold value LS is a value corresponding to the distance LP between the position PF and the position PD shown in FIG. The position PF indicates a position on an extension line in the vertical direction passing through the rotation center of the rotation shaft of the first feed rolls 5A and 5B. When the rear end (right end in FIG. 2) of the corrugated board sheet SH is located at the position PD, the feeding direction of the corrugated board sheet SH when the front end (left end in FIG. 2) of the corrugated board sheet SH is located at the position PF. The sheet length of DF corresponds to the distance LP. In the present embodiment, the distance LP is 400 mm.

  An operation panel 142 is connected to the paper feed control device 110. The operation panel 142 includes various buttons operated by an operator and supplies various operation information to the paper feed control device 110. The various buttons are a paper feed button 143 and the like. The paper feed button 143 is a button for the operator to instruct the start of the paper feed operation. The origin detector HD is connected to the paper feed control device 110 and supplies a detection signal to the paper feed control device 110.

  A suction control device 146, a cam adjustment control device 147, a coupling control device 148, and a cover control device 149 are connected to the paper feed control device 110 and receive control commands from the paper feed control device 110. The suction control device 146 receives a speed control command from the paper feed control device 110 and controls the frequency of the drive signal of the blower motor 18 in accordance with the speed control command. The cam adjustment control device 147 receives a control command for commanding the rotation phase of the second cam 24B from the paper feed control device 110, rotates the servo motor 43, and from the pulse generator PG2 as the servo motor 43 rotates. The number of generated pulses is counted, the phase of the pulse is detected, and the rotation amount and rotation direction of the servo motor 43 are controlled. The coupling control device 148 receives a control command for commanding transmission and interruption of the rotational force to the paper feed roll 13D from the paper feed control device 110, and controls the operation of the air cylinder 40. The cover control device 149 receives a control command for commanding the movement of the cover member 58 to the operating position or the non-operating position from the paper feed control device 110 and controls the operation of the air cylinder 60.

<< Operation and Action of First Embodiment >>
The operation and action of the sheet feeding unit 2 of the corrugated board box making machine 1 according to the first embodiment will be described with reference to FIG. When the cardboard sheet box making machine 1 is powered on, the management apparatus 100 supplies a speed control command for instructing the conveyance speed of the corrugated cardboard sheet to the motor control apparatus 130 according to the order scheduled to be executed. At this time, the motor control device 130 does not start the main drive motor MT.

  The paper feed control device 110 temporarily stores in the work memory 141 information such as a control command and an order to be executed supplied from the management device 100 and a sheet length. When the cardboard sheet box making machine 1 is powered on, the paper feed control device 110 reads the paper feed control program from the program memory 140 and executes it.

<Paper control processing>
When the paper feed control program is executed, the paper feed control process shown in FIG. 7 is executed. Each process illustrated in FIG. 7 is a process executed by the paper feed control device 110.

  In S1, it is determined whether or not a new order is started. Specifically, the paper feed control device 110 determines whether or not a new order start command has been received from the management device 100. When it is determined that a new order is to be started (S1: YES), the process of S2 is executed. When it is not determined that a new order is started (S1: NO), the determination process of S1 is repeatedly executed.

  In S <b> 2, the sheet length in the sheet feeding direction of the corrugated cardboard sheet processed in the new order is temporarily stored in the work memory 141. Specifically, the paper feed control device 110 receives information necessary for executing a new order from the management device 100, and temporarily stores the sheet length included in the received information in the work memory 141.

  In S3, it is determined whether or not the sheet length stored in the work memory 141 is equal to or less than the threshold value LS. When the sheet length exceeds the threshold LS (S3: NO), the process of S4 is executed. When the sheet length is equal to or less than the threshold LS (S3: YES), the process of S7 is executed.

  The processes of S4 to S6 are executed to feed a corrugated sheet having a normal length or a relatively long corrugated sheet whose sheet length exceeds the threshold LS. First, in S4, the air cylinder 40 is operated so that a connecting operation for connecting the clutch members 36 and 37 is executed. Specifically, the paper feed control device 110 supplies a control command for instructing a coupling operation to the coupling control device 148. The coupling control device 148 operates the air cylinder 40 according to the control command so that the operating rod 40A of the air cylinder 40 protrudes. As a result, the clutch members 36 and 37 are engaged with each other, and the rotation shaft 30D of the paper feed roll 13D is connected to the output shaft 35D of the speed increasing mechanism 32.

  In S5, the air cylinder 60 is operated such that the cover member 58 performs a retreat operation in which the cover member 58 retreats from the arrangement region R1 of the four paper feed rolls 13A to 13D. Specifically, the paper feed control device 110 supplies a control command for instructing a retracting operation to the cover control device 149. The cover control device 149 operates the air cylinder 60 according to the control command so that the operating rod 60A of the air cylinder 60 is retracted. By the operation of the air cylinder 60, the cover member 58 is retracted from the arrangement region R1 of the paper feed rolls 13A to 13D as shown in FIG. As a result, all of the paper feed rolls 13A to 13D come into contact with the corrugated cardboard sheet and can apply a conveyance force.

  In S6, the rotational phase of the second cam 24B with respect to the first cam 24A is adjusted according to the sheet length. Specifically, when the sheet length exceeds the threshold value LS, the sheet feeding control device 110 controls the rotation phase of the second cam 24B corresponding to the sheet length of the cardboard sheet processed in the new order. The command is supplied to the cam adjustment control device 147. The cam adjustment control device 147 controls the rotation direction and the rotation amount of the servo motor 43 in accordance with the control command. As a result, the rotation phase of the second cam 24B relative to the first cam 24A is adjusted by the rotation of the servo motor 43, and the rising timing of the great 19 is set. FIG. 8 shows the position of the lowermost corrugated cardboard sheet SH being fed immediately after the great 19 has been lifted from the paper feed table 10.

  The processes of S7 to S9 are executed to feed a relatively short cardboard sheet whose sheet length is equal to or less than the threshold value LS. First, in S <b> 7, the air cylinder 40 is operated so that a disconnection operation for disconnecting the clutch members 36 and 37 is performed. Specifically, the paper feed control device 110 supplies a control command for instructing a blocking operation to the coupling control device 148. The coupling control device 148 operates the air cylinder 40 according to the control command so that the operating rod 40A of the air cylinder 40 is retracted. By the operation of the air cylinder 40, the clutch member 37 is separated from the clutch member 36, and the connection between the rotation shaft 30D of the paper feed roll 13D and the output shaft 35D of the speed increasing mechanism 32 is cut off. As a result, the sheet feeding roller 13D can be freely rotated without transmitting the rotational force from the output shaft 30D.

  In S8, the air cylinder 60 is operated so that the cover member 58 performs a covering operation that covers the arrangement region R2 of the paper feed roll 13D. Specifically, the paper feed control device 110 supplies a control command for instructing a cover operation to the cover control device 149. The cover control device 149 operates the air cylinder 60 according to the control command so that the operating rod 60A of the air cylinder 60 protrudes. By the operation of the air cylinder 60, as shown in FIG. 9, the cover member 58 covers the arrangement region R2 of the paper feed roll 13D. As a result, the paper feed rolls 13A to 13C are in a state where they can contact the corrugated cardboard sheet and apply a conveying force, but the paper feed roll 13D cannot contact the cardboard sheet.

  In S9, the rotational phase of the second cam 24B relative to the first cam 24A is adjusted according to the sheet length and the cover length. The covering length is the length in the sheet feeding direction DF of the arrangement region R2 of the sheet feeding roll 13D shown in FIG. 9, and in this embodiment is the interval between the rotation centers of the rotation axes of two adjacent sheet feeding rolls. Corresponds to the distance between axes. Specifically, when the sheet length is equal to or less than the threshold value LS, the sheet feeding control device 110 rotates the second cam 24B corresponding to the sheet length and the cover length of the cardboard sheet processed in the new order. A control command for commanding the phase is supplied to the cam adjustment control device 147. The cam adjustment control device 147 controls the rotation direction and the rotation amount of the servo motor 43 in accordance with the control command. As a result, the rotation phase of the second cam 24B relative to the first cam 24A is adjusted by the rotation of the servo motor 43, and the rising timing of the great 19 is set. FIG. 9 shows the position of the lowermost corrugated cardboard sheet SH being fed immediately after the great 19 is lifted from the paper feed table 10.

  In S10, it is determined whether or not the paper feed button 143 has been operated. When it is determined that the paper feed button 143 has been operated (S10: YES), the process of S11 is executed. When it is not determined that the paper feed button 143 has been operated (S10: NO), the determination process of S10 is repeatedly executed. In general, in order to execute an order, an operator starts a sheet feeding operation after stacking a large number of cardboard sheets in an accommodation space defined by the front gate 11 and the back guide 12 of the sheet feeding mechanism 4. The paper feed button 143 is operated.

  In S11, the main drive motor MT and the blower motor 18 are driven. Specifically, the paper feed control device 110 supplies a request command for requesting driving of the main drive motor MT to the management device 100. Further, the paper feed control device 110 reads the initial setting value of the frequency of the drive signal of the blower motor 18 from the program memory 140 and supplies the initial setting value to the suction control device 146. The suction controller 146 controls the rotation speed of the blower motor 18 according to the frequency of the initial setting value. Due to the rotation of the blower motor 18, a negative pressure corresponding to the frequency of the initial setting value is generated in the suction chamber 16.

  The management device 100 instructs the motor control device 130 to drive the main drive motor MT in accordance with a request command from the paper feed control device 110. The motor control device 130 activates the main drive motor MT according to the drive command, and controls the rotation speed of the main drive motor MT according to the speed control command supplied from the management device 100. When the main drive motor MT rotates, the drive gear 29 rotates in the arrow direction CD shown in FIG. As the drive gear 29 rotates, both the cams 24A and 24B rotate and the paper feed rolls 13A to 13D rotate. When the main drive motor MT rotates, the first feed rolls 5A and 5B and the second feed rolls 6A and 6B also rotate, and the peripheral speed of each feed roll corresponds to the conveyance speed of the corrugated cardboard sheet according to the order. Become speed. Further, the rotation of the main drive motor MT causes the printing cylinder 8 and the press roll 9 of the printing unit 3 to rotate, and the processing cylinders of other processing units also rotate.

  When both the cams 24A and 24B rotate, the swinging body 25 swings according to the engagement between the cam follower 28 and the cam surfaces of the both cams 24A and 24B. Along with this swinging, the great 19 moves up and down with respect to the paper feed rolls 13A to 13D, and the cardboard sheet feeding operation is started. In the case of a relatively long cardboard sheet whose sheet length exceeds the threshold value LS, the lowermost corrugated cardboard sheet SH is fed by the negative pressure of the suction chamber 16 when the great 19 descends below the upper surface of the paper feed rolls 13A to 13D. Sucked by the paper rolls 13A to 13D, the conveyance force in the paper feeding direction DF is received from the four paper feeding rolls 13A to 13D. In the case where the sheet length is a relatively short cardboard sheet whose length is equal to or less than the threshold value LS, when the great 19 descends below the upper surface of the sheet feeding rolls 13A to 13D, the lowermost cardboard sheet SH is fed by the negative pressure of the suction chamber 16 It is sucked by the paper rolls 13A to 13C and receives the conveying force in the paper feeding direction DF from the three paper feeding rolls 13A to 13C. However, since the paper feed roll 13D is covered by the cover member 58, the suction force due to the negative pressure in the suction chamber 16 hardly acts on the cardboard sheet SH or is extremely weak in the arrangement region R2 of the paper feed roll 13D.

  In S12, a paper feed process for executing the order is executed. Specifically, the sheet feeding control device 110 counts the number of cardboard sheets fed during execution of the current order based on the origin detection signal supplied from the origin detector HD. Further, the paper feed control device 110 monitors the paper feed status of the cardboard sheet SH by a known detector that detects the end of the cardboard sheet.

  In S13, it is determined whether or not the order is completed. Specifically, the paper feed control device 110 determines whether or not the number of sheets counted in S12 has reached the number of sheets determined for the order. When it is determined that the order has been completed (S13: YES), the process of S14 is executed. When it is not determined that the order has been completed (S13: NO), the process returns to the process of S12 and is executed.

  In S14, stop control of the main drive motor MT and the blower motor 18 is executed. Specifically, the paper feed control device 110 supplies a stop command to the suction control device 146 to stop the blower motor 18. In addition, the paper feed control device 110 supplies a stop request for the main drive motor MT to the management device 100. The management apparatus 100 supplies an origin detection signal from the origin detector HD after detecting that the last corrugated sheet of the current order has passed through the die cutter unit arranged at the rearmost stage in the corrugated cardboard box making machine 1. When received from the paper control device 110, a stop command is supplied to the motor control device 130 to stop the main drive motor MT.

  When the process of S14 ends, the process returns to the process of S11, and the processes of S1 to S14 are similarly executed for the new order.

<Feeding operation for relatively long cardboard sheets>
In the present embodiment, the threshold value LS is a value corresponding to a sheet length of 400 mm, and the sheet length of the relatively long cardboard sheet SH shown in FIG. 8 is 740 mm, which is sufficiently longer than the threshold value LS. When a relatively long cardboard sheet is fed in this way, the cover member 58 is retracted from the arrangement region R1 of the paper feed rolls 13A to 13D, and the cardboard sheet SH receives a large conveyance force from the four paper feed rolls 13A to 13D. . When the rear end (right end in FIG. 8) of the lowermost corrugated cardboard sheet SH reaches the position PB on the extension line in the vertical direction passing through the rotation center of the rotation shaft 30B of the sheet feed roll 13B, the great 19 Rise from the top. The rising timing of the great 19 is the timing adjusted by the process of S6. Due to the rise of the great 19, the conveying force from the four paper supply rolls 13 </ b> A to 13 </ b> D is not applied to the lowermost corrugated cardboard sheet SH. At this time point, the lowermost corrugated cardboard sheet SH is sandwiched between the first feed rolls 5A and 5B and the second feed rolls 6A and 6B and receives a large conveying force.

  Until the rear end of the lowermost corrugated cardboard sheet SH passes the paper feed roll 13D and reaches the position PB, the second corrugated cardboard sheet from the lowermost layer is fed by the negative pressure of the suction chamber 16 to the paper feed roll 13C, It is sucked by 13D and makes frictional contact with the rotating paper feed rolls 13C and 13D. However, since the frictional contact is short, the lower surface of the second corrugated cardboard sheet is not damaged. In addition, when the second corrugated cardboard sheet from the bottom is sucked, the lowermost corrugated cardboard sheet SH is sandwiched between the upper surface of the sheet feeding table 10 and the lower surface of the second corrugated cardboard sheet and receives a frictional resistance. Since the feed rolls 5A, 5B, 6A and 6B receive a large conveying force, the sheet feeding operation of the lowermost corrugated cardboard sheet SH is hardly affected by the frictional resistance.

<Feeding operation of relatively short cardboard sheets>
The sheet length of the relatively short corrugated cardboard sheet SH shown in FIG. 9 is the same length as the threshold LS and is 400 mm. When the relatively short cardboard sheet is fed in this way, the cover member 58 covers the arrangement region R2 of the paper feed roll 13D, and the cardboard sheet SH receives the conveyance force from the three paper feed rolls 13A to 13C. When the rear end (the right end in FIG. 9) of the lowermost corrugated cardboard sheet SH reaches the position PA on the vertical extension line passing through the rotation center of the rotary shaft 30A of the paper feed roll 13A, the great 19 Rise from the top. The rise timing of the great 19 is the timing adjusted by the process of S9. Due to the rise of the great 19, the conveying force from the three paper supply rolls 13 </ b> A to 13 </ b> C is not applied to the lowermost corrugated cardboard sheet SH. At this time, the lowermost corrugated cardboard sheet SH is sandwiched between the first feed rolls 5A and 5B and receives a conveying force.

  Since the cover member 58 covers the arrangement region R2 of the paper feed roll 13D, the suction force for sucking the cardboard sheet is extremely small in the arrangement region R2. Until the rear end of the lowermost corrugated cardboard sheet SH passes the paper feed roll 13C and reaches the position PA, the second corrugated cardboard sheet from the bottom is fed by the negative pressure of the suction chamber 16 to the paper feed rolls 13B and 13C. And is in frictional contact with the rotating paper feed rolls 13B and 13C. However, since the frictional contact is short, the lower surface of the second corrugated cardboard sheet from the bottom is not damaged. Further, when the second corrugated cardboard sheet from the bottom is sucked, the lowermost corrugated cardboard sheet SH is sandwiched between the upper surface of the paper feeding table 10 and the lower surface of the second corrugated cardboard sheet from the bottom to reduce the frictional resistance. However, since the suction force is extremely small in the arrangement region R2 of the sheet feed roll 13D and a large conveying force is received from the first feed rolls 5A and 5B, the sheet feeding operation of the lowermost corrugated cardboard sheet SH is a friction resistance. Is hardly affected by.

  Since the rise timing of the great 19 is adjusted and delayed by the process of S9, the time during which the three sheet feeding rolls 13A to 13C apply the conveying force to the lowermost corrugated cardboard sheet SH becomes longer, and the lowermost layer Until the leading end of the corrugated cardboard sheet is securely clamped by the first feed rolls 5A and 5B, the conveyance force by the three paper feed rolls 13A to 13C can be continuously applied to the lowermost corrugated cardboard sheet.

  The operation in which the rising timing of the great 19 is delayed by the processing of S9 will be described in detail with reference to FIGS. FIG. 10 shows a case where a relatively short corrugated cardboard sheet SH having a sheet length of 400 mm is fed, and the process of S6 is executed instead of the process of S9, and the ascending timing of the great 19 is not delayed. A relatively short corrugated cardboard sheet SH feeding state in an assumed case is shown. 11 shows the peripheral speed of the paper feed rolls 13A to 13D, the elevation distance of the great 19 with respect to the paper feed table, the paper feed distance of the corrugated cardboard sheet SH by the paper feed rolls 13A to 13D, and the rotation angle of the drive shaft 23. It is a timing chart which shows a relationship. In FIG. 11, the period of the rotation angle 0 ° to 360 ° of the drive shaft 23 is the paper feed cycle, and at time TS, the Great 19 descends from the paper feed table 10 in each paper feed cycle and the paper feed operation starts. It is time to be done. The distance DS is the minimum sheet feeding distance at which the great 19 moves up from the sheet feeding table 10 to feed the corrugated cardboard sheet, and is determined based on the minimum sheet length of the corrugated cardboard sheet that can be fed. The distance DL is the maximum sheet feeding distance, and is determined based on the minimum sheet length and the circumferential lengths of the first and second cams 24A and 24B.

  In FIG. 10, when the rear end of the lowermost corrugated cardboard sheet SH (the right end in FIG. 10) reaches the position PB on the vertical extension line passing through the rotation center of the rotation shaft 30B of the paper feed roll 13B, the great 19 is fed. Ascending from the upper surface of the paper table 10. The rise timing of the great 19 is a timing when it is assumed that the adjustment is performed by the process of S6. In general, the rising timing of the great is adjusted so that the rear end of the corrugated cardboard sheet is immediately before passing through the paper feed roll 13D which is the most upstream paper feed roll. However, in this embodiment, in order to give a conveying force to a short cardboard sheet having a sheet length of 400 mm or less for a long time, when the rear end of the cardboard sheet passes through the paper feed roll 13D and reaches the position PB. The rotational phase of the second cam 24B relative to the first cam 24A is adjusted so that the great 19 rises. The rotational phase of the second cam is adjusted such that the longer the sheet length, the longer the time during which the conveying force is applied. By increasing the time during which the conveying force is applied, the sheet feeding distance increases as the rise timing of the great 19 is delayed, as shown in FIG.

  For example, assuming that the rising timing of the great 19 is adjusted by the process of S6 in order to feed a relatively short cardboard sheet having a sheet length of 400 mm or less corresponding to the threshold LS, the great 19 is fed at the time T1. The distance of the relatively short corrugated cardboard sheet rising from the paper table 10 is a distance DX1 shown in FIG. On the other hand, when the rising timing of the great 19 is adjusted by the process of S9, the great 19 rises from the paper feeding table 10 at a time T2 delayed from the time T1, and the paper feeding distance of this relatively short cardboard sheet Is a distance DX2 larger than the distance DX1 shown in FIG. The time that the time point T2 is delayed from the time point T1 is determined based on the cover length, which is the length of the paper feed roll 13D in the paper feed direction DF, and the paper feed speed.

<< Effects of First Embodiment >>
In the present embodiment, the cover member 58 covers the arrangement area R2 of the paper feed roll 13D when a relatively short cardboard sheet SH having a threshold value LS or less is fed, so that the suction force in the arrangement area R2 is extremely small. . The lowermost corrugated cardboard sheet SH receives frictional resistance while being fed while being sandwiched between the lower surface of the second corrugated cardboard sheet from the lowermost layer and the upper surface of the paper feed table 10. Since this frictional resistance changes according to the suction force acting on the second corrugated cardboard sheet, the frictional resistance is also reduced by reducing the suction force in the arrangement region R2. On the other hand, since the suction force of the suction mechanism 14 is not reduced, the lowermost corrugated cardboard sheet SH can be sucked in the arrangement region of the three paper feed rolls 13A to 13C and receive a relatively large transport force. As a result, since the magnitude of the conveying force is maintained while reducing the frictional resistance, the lowermost corrugated cardboard sheet SH can be fed accurately.

  In the present embodiment, when a relatively short corrugated cardboard sheet SH having a threshold value LS or less is fed, the rotation phase of the second cam 24B is set so that the rising timing of the great 19 is delayed by the process of S9. Adjusted for 24A. The lowermost corrugated cardboard sheet SH receives the conveying force from the three sheet feeding rolls 13A to 13C for a longer time as the rising timing is delayed. As a result, the lowermost corrugated cardboard sheet SH can be fed with higher accuracy.

  In the present embodiment, when the cover member 58 covers the arrangement region R2 of the paper feed roll 13D, the connection between the rotation shaft 30D of the paper feed roll 13D and the output shaft 35D of the speed increasing mechanism 32 is cut off, and the paper feed roll 13D. Can be freely rotated. Even if the cover member 58 is disposed in contact with the paper feed roll 13D, the paper feed roll 13D is worn by contact with the cover member 58 because no rotational force is applied to the paper feed roll 13D. Can be prevented. Further, since the cover member 58 can be prevented from being worn, the thickness of the cover member 58 can be reduced so that the protrusion from the upper surface of the paper feed table 10 can be avoided as much as possible. The cover member 58 can be easily disposed in a narrow space between the back guide 12 and the lower end of the back guide 12.

  In the present embodiment, the threshold value LS is set to a value corresponding to the distance LP between the position PF and the position PD. As a result, even when the sheet length is a normal corrugated cardboard sheet slightly exceeding the distance LP, it is possible to feed a sheet with a large conveying force applied by the four sheet feeding rolls 13A to 13D. On the other hand, when the sheet length is a corrugated sheet that is considerably shorter than the distance LP, after the rear end of the corrugated sheet passes through the arrangement region R2 of the sheet feeding roll 13D, the leading end of the corrugated sheet is the first feed roll 5A. The sheet can be fed with a conveying force applied by the three sheet feeding rolls 13A to 13C until it is nipped by 5B. Further, by restricting the suction force in the arrangement region R2 of the paper feed roll 13D, the suction force acting on the second corrugated cardboard sheet from the lowermost layer is weakened, and the frictional resistance acting on the lowermost corrugated cardboard sheet SH can be reduced. it can.

[Second Embodiment]
A second embodiment in which the paper feeding device of the present invention is applied to a corrugated board box making machine will be described below with reference to the accompanying drawings. The suction restriction mechanism 7 of the first embodiment is configured to include the cover member 58, whereas the suction restriction mechanism 70 of the second embodiment is configured to include the shielding wall 71. In the second embodiment, the same parts as those in the first embodiment are denoted by the same symbols, and the description thereof is omitted.

(Detailed configuration of the suction regulating mechanism 70)
With reference to FIG. 12, the structure of the suction restriction mechanism 70 of the second embodiment will be described. FIG. 12 is an enlarged front view showing the paper feed mechanism 4 in the second embodiment. In FIG. 12, the suction restriction mechanism 70 mainly includes a shielding wall 71, a support mechanism 72, and an air cylinder 73.

  The support mechanism 72 includes a support shaft 74 that is rotatably attached to the inner bottom surface of the suction chamber 16, and a swing lever 75. The support shaft 74 is disposed at a position close to the suction port 16A below the paper feed roll 13D. The axis of the support shaft 74 extends in the front-rear direction. The shielding wall 71 extends in the front-rear direction along the rotation shaft 30 </ b> D of the paper feed roll 13 </ b> D, and is fixed to the support shaft 74. One end of the support shaft 74 protrudes outside the suction chamber 16, and the swing lever 75 is fixed to one end of the support shaft 74. The air cylinder 73 is attached to the frame of the paper feed mechanism 4 and has an operating rod 73A. The distal end of the operating rod 73A is connected to the swing lever 75. An elastic body 76 is fixed to the tip of the shielding wall 71.

  When the operating rod 73A of the air cylinder 73 protrudes, the shielding wall 71 rotates to an upright position that stands up from the inner bottom surface of the suction chamber 16 as shown by a solid line in FIG. When the operating rod 73 </ b> A of the air cylinder 73 is retracted, the shielding wall 71 rotates to the lying position where it falls on the inner bottom surface of the suction chamber 16 as shown by a two-dot chain line in FIG. 12. When the shielding wall 71 is located at the standing position, the tip of the shielding wall 71 is located near the outer peripheral surface of the paper feed roller 13D, and the elastic body 76 contacts the outer peripheral surface of the paper feed roller 13D. As a result, the shielding wall 71 in the standing position blocks the space existing below the sheet feed roller 13D from communicating with the suction port 16A inside the suction chamber 16, and weakens the suction force in the space. . On the contrary, when the shielding wall 71 is located at the lying position, the space existing below the paper feed roller 13D communicates with the suction port 16A, and the suction force in the space is that of the other paper feed rollers 13A to 13C. It becomes the same as the suction force in the space existing below and becomes stronger.

  In FIG. 12, when the shielding wall 71 is located at the upright position, in this embodiment, the shielding wall 71 is the paper feed roll 13 </ b> D disposed on the most upstream side in the paper feeding direction DF among the paper feed rolls 13 </ b> A to 13 </ b> D. Are arranged from the arrangement area of the paper rolls 13A to 13C. The arrangement area of the paper feed roll 13D will be specifically described. In FIG. 12, an area R1 indicates a range of a space existing below the sheet feed rolls 13A to 13C, which is an arrangement area of the sheet feed rolls 13A to 13D in the sheet feeding direction DF, and the sheet is fed from the left end of the sheet feed roll 13A. This is an area in the range up to the right end of the roll 13D. An area R3 indicates a range of a space existing below the paper feed roll 13D in the arrangement area R1 of the paper feed rolls 13A to 13D. The position PC indicates a position on an extension line in the vertical direction passing through the rotation center of the rotation shaft 30C of the paper feed roll 13C, and the position PD is on an extension line in the vertical direction passing through the rotation center of the rotation shaft 30D of the paper feed roll 13D. Indicates the position. Further, the position PC and the position PD may be considered to indicate positions on an extension line in the vertical direction passing through a contact point where the paper feed rolls 13C and 13D are in contact with the lower surface of the cardboard sheet SH. In the present embodiment, the shielding wall 71 in the standing position extends upward between the position PC and the position PD. The left end of the region R3 is located on the extended line of the shielding wall 71 in the standing position. The region R3 is a region in a range from the position on the extension line to the right end of the paper feed roll 13D, and corresponds to an arrangement region of the paper feed roll 13D.

  The electrical configuration of the second embodiment is the same as that of the first embodiment except that a cover control device for controlling the operation of the air cylinder 73 is provided instead of the cover control device 149 of the first embodiment shown in FIG. Since the electrical configuration is the same as that of the embodiment, the description thereof is omitted.

<< Operation and Action of Second Embodiment >>
The operation and action of the sheet feeding unit 2 of the corrugated cardboard box making machine 1 according to the second embodiment will be described. The paper feed control process in the second embodiment is the same as the paper feed control process in the first embodiment except for the processes of S5, S8 and S9 shown in FIG. 7, and only different processes will be described.

  In S3 shown in FIG. 7, when it is not determined that the sheet length is equal to or less than the threshold value LS (S3: NO), the shielding wall 71 falls on the inner bottom surface of the suction chamber 16 instead of S5 shown in FIG. The air cylinder 73 is actuated so as to execute a lying down motion that rotates to the lying down position. Specifically, the paper feed control device 110 supplies a control command for commanding a lying down operation to the shielding control device. In accordance with the control command, the shielding control device operates the air cylinder 73 so that the operating rod 73A of the air cylinder 73 protrudes. By the operation of the air cylinder 73, the shielding wall 71 falls on the inner bottom surface of the suction chamber 16 as shown by a two-dot chain line in FIG. As a result, the corrugated board sheet SH is sucked in the arrangement region R1 of the four paper feed rolls 13A to 13D, and all of the paper feed rolls 13A to 13D come into contact with the corrugated board sheet and can apply conveyance force. .

  On the other hand, when it is determined in S3 shown in FIG. 7 that the sheet length is equal to or smaller than the threshold LS (S3: YES), the shielding wall 71 is placed on the inner bottom surface of the suction chamber 16 instead of S8 shown in FIG. The air cylinder 73 is actuated so that a standing operation that rotates to the standing position is performed. Specifically, the paper feed control device 110 supplies a control command for instructing an upright operation to the shielding control device. The shielding control device operates the air cylinder 73 according to the control command so that the operating rod 73A of the air cylinder 73 is retracted. By the operation of the air cylinder 73, the shielding wall 71 rises from the inner bottom surface of the suction chamber 16 as shown by a solid line in FIG. By the standing of the shielding wall 71, the corrugated cardboard sheet SH is sucked in the arrangement area of the three paper feed rolls 13A to 13C, but the suction force becomes extremely weak in the arrangement area R3 of the paper feed roll 13D. As a result, the three paper feed rolls 13A to 13C come into contact with the corrugated cardboard sheet SH by the suction force and can apply the transport force.

  Next, instead of S9 shown in FIG. 7, the rotational phase of the second cam 24B relative to the first cam 24A is adjusted according to the sheet length and the shielding length. The shielding length is the length in the sheet feeding direction DF of the arrangement region R3 of the sheet feeding roll 13D shown in FIG. Specifically, the sheet feeding control device 110 rotates the second cam 24B corresponding to the sheet length and shielding length of the corrugated cardboard sheet processed in the new order when the sheet length is equal to or less than the threshold value LS. A control command for commanding the phase is supplied to the cam adjustment control device 147. The cam adjustment control device 147 controls the rotation direction and the rotation amount of the servo motor 43 in accordance with the control command. As a result, the rotation phase of the second cam 24B relative to the first cam 24A is adjusted by the rotation of the servo motor 43, and the rising timing of the great 19 is set.

<< Effect of Second Embodiment >>
In the present embodiment, since the shielding wall 71 is disposed inside the suction chamber 16 having a relatively large space in order to regulate the suction force in the arrangement region R3 of the paper feed roll 13D, in the first embodiment. Compared to the configuration in which the cover member 58 is disposed in a relatively narrow space between the upper surface of the paper feed table 10 and the lower end of the back guide 12, the shielding wall 71 can be easily assembled to the paper feed mechanism 4.

  In the present embodiment, since the connection between the rotation shaft 30D of the paper feed roll 13D and the output shaft 35D of the speed increasing mechanism 32 is cut off by the process of S7, the lower surface of the second corrugated cardboard sheet from the bottom layer is fed. It is possible to prevent damage due to friction with the roll 13D.

[Correspondence between Configurations of Present Invention and Embodiment]
The paper feed rolls 13A to 13D, the suction mechanism 14, and the paper feed unit 2 are examples of the paper feed roll, the suction mechanism, and the paper feed device of the present invention. The printing unit 3 is an example of a downstream processing apparatus of the present invention. 1st feed roll 5A, 5B is an example of a pair of feed roll of this invention. The suction chamber 16 and the suction port 16A are examples of the suction chamber and the suction port of the present invention. The great 19 is an example of the lifting member of the present invention. The cam adjustment mechanism 22 is an example of the adjustment mechanism of the present invention. The main drive motor MT is an example of the rotation drive unit of the present invention. The coupling mechanism 34 and the coupling control device 148 are examples of the stopping means of the present invention. The pair of clutch members 36 and 37 is an example of the clutch mechanism of the present invention. The suction restriction mechanism 7 and the suction restriction mechanism 70 are examples of the suction restriction means of the present invention. The cover member 58 is an example of the cover member of the present invention, and the shielding wall 71 and the elastic body 76 are examples of the separation wall of the present invention. The paper feed control device 110 that executes the processes of S3, S5, and S8 is an example of the control unit of the present invention. The region R1 is an example of a region where a plurality of paper feed rolls according to the present invention is arranged, and the region R2 and the region R3 are examples of a region where some upstream paper feed rolls of the present invention are arranged. The space that exists below the sheet feed roll 13D and the space that exists below the sheet feed rolls 13A to 13C are examples of the first space and the second space of the present invention. The process of S5 is an example of the “step for applying a suction force” in the present invention, and the process of S8 is an example of the “step for regulating the suction force” in the present invention.

[Modification]
The embodiment of the present invention has been described above, but various modifications can be made by those skilled in the art without departing from the spirit of the present invention.

(1) In both embodiments, the paper feed unit 2 includes four paper feed rolls 13A to 13D, and the cover member 58 covers the region R2 where the paper feed roll 13D is disposed, or the shielding wall 17 and the elasticity. The body 76 is configured to shield the region R3 that is the arrangement region of the paper feed roll 13D, but is not limited to this configuration. For example, the sheet feeding unit may be configured to include three sheet feeding rolls or five or more sheet feeding rolls. When five or more sheet feeding rolls are provided, the arrangement area of the two or more sheet feeding rolls on the upstream side may be covered with a cover member or shielded with a shielding wall or the like.

(2) In both embodiments, the suction mechanism 14 is configured to include one suction chamber 16 that accommodates the four paper feed rolls 13A to 13D and one blower motor 18, but the configuration is not limited thereto. For example, the suction mechanism generates negative pressures in the first suction chamber that houses three paper feed rolls, the second suction chamber that contains one paper feed roll, and the first and second suction chambers, respectively. The structure provided with a 1st and 2nd blower motor may be sufficient. In the configuration of this modification, the suction restricting means may be configured to reduce the suction force by the second blower motor without providing the cover member and the shielding wall.

(3) In both embodiments, the main drive motor MT includes four sheet feed rolls 13A to 13D, a drive mechanism 21 that moves the great 19 up and down, and first and second feed rolls 5A, 5B, 6A, and 6B. However, the present invention is not limited to this configuration. For example, a configuration in which four drive motors drive four paper feed rolls in synchronization with each other may be employed. In the configuration of this modified example, the stopping means may be a mode control unit that stops the drive motor that drives the most upstream sheet feed roll instead of the coupling mechanism 34, and the drive motor and the most upstream side are also configured. A configuration similar to the coupling mechanism 34 may be provided between the paper feed rolls.

(4) In both embodiments, the sheet length threshold LS is set to a value corresponding to the distance LP shown in FIG. 2, but the setting method of the threshold LS is not limited to the setting method in both embodiments. Usually, a horizontal ruled line is provided at a predetermined interval from both ends of the corrugated cardboard sheet by a corrugating machine scorer. Also in the corrugated cardboard sheet SH shown in FIGS. 2 and 12, the horizontal ruled lines are perpendicular to the sheet feeding direction DF, with a predetermined horizontal ruled line spacing from the leading and trailing ends (left and right ends in both figures) of the corrugated cardboard sheet SH. It is applied in the direction (front-rear direction in both figures). When the portion with the horizontal ruled line at the front end of the corrugated cardboard sheet passes through the nip portion of the first feed rolls 5A, 5B, the contact state between the part with the horizontal ruled line and the two feed rolls 5A, 5B is The cardboard sheet feeding operation may be disturbed. In consideration of the disturbance of the sheet feeding operation, the sheet length threshold value can be set to a value obtained by adding a predetermined horizontal ruled line interval to the distance LP shown in FIG. In this case, since the predetermined horizontal ruled line interval is different for each order, a sheet length threshold corresponding to the predetermined horizontal ruled line interval is calculated and set. In this modified example, when the sheet length of the corrugated cardboard sheet is equal to or less than the threshold value obtained by adding the predetermined horizontal ruled line interval to the distance LP, the process of S9 delays the rising timing of the great 19, so that the horizontal ruled line is The three paper feed rolls 13A to 13C can apply a conveying force to the corrugated cardboard sheet SH until the applied portion passes through the nip portions of the two feed rolls 5A and 5B, and the corrugated cardboard sheet is fed with higher accuracy. be able to.

(5) In both embodiments, the region R2 or the region R3 corresponding to the arrangement region of the one sheet feeding roll 13D located on the most upstream side is covered with the cover member 58 or shielded by the shielding wall 71 or the like. However, the present invention is not limited to this configuration. For example, when restricting the suction force of the suction mechanism in the arrangement area of a plurality of paper feed rolls located on the upstream side, the longer the length of the cardboard sheet in the paper feed direction, the more the number of paper feed rolls covered by the cover member. By such a method as to decrease, the arrangement area of the paper feed rolls whose suction force is regulated is reduced. When the length of the corrugated cardboard sheet exceeds a predetermined length, the configuration is such that there is no paper feed roll placement area where the suction force is regulated by a method such as retracting the cover member from the paper feed roll placement area. May be.

(6) In both embodiments, the coupling mechanism 34 is configured to connect and shut off the rotation shaft 30D of the paper feed roll 13D and the output shaft 35D of the speed increasing mechanism 32, but the suction force of the suction mechanism 14 Any configuration may be used as long as the rotational force can be prevented from being transmitted from the paper feed roll 13D to the cover member 58 or the lowermost corrugated cardboard sheet. For example, when the suction force of the suction mechanism 14 is restricted, a configuration in which only the paper feed roll 13D is lowered from the upper surface of the paper feed table 10 while the paper feed roll 13D is continuously rotated may be employed.

(7) In both embodiments, the cam adjustment mechanism 22 includes the wave gear mechanism 24 and the servo motor 43, but can adjust the rotation phases of the first and second cams 24BA, 24B. Any configuration can be used. For example, without providing the servo motor 43 and the cam adjustment control device 147, the rotation phase of the first and second cams 24BA and 24B is adjusted by rotating the gear 50 shown in FIG. The structure to do may be sufficient.

(8) In the first embodiment, in the process of S9, the rising timing of the great 19 is determined by adjusting the rotational phase of the second cam 24B relative to the first cam 24A according to the sheet length and the cover length. Is done. The covering length is the length in the sheet feeding direction DF of the region R2 where the cover member 58 covers one sheet feeding roller 13D, and in the embodiment, is the distance between the axes of two adjacent sheet feeding rollers. When the cover member covers a plurality of paper feed rollers, the cover length is a length obtained by multiplying the distance between the axes and the number of paper feed rollers to be covered. The covering length is not limited to the inter-axis distance, and may be the actual length in the sheet feeding direction of the area covered by the cover member. In the second embodiment, the rotational phase of the second cam 24B relative to the first cam 24A is adjusted according to the sheet length and the shielding length. The shielding length is the length in the sheet feeding direction DF of the arrangement region R3 of the sheet feeding roll 13D shown in FIG. However, the shielding length may be an inter-axis distance or an actual length in the sheet feeding direction of the arrangement region R3, similar to the covering length.

2 Feeding unit 3 Printing units 5A, 5B, Feed rolls 7, 70 Suction regulating mechanisms 13A to 13D Feeding roll 14 Suction mechanism 16 Suction chamber 16A Suction port 19 Great 22 Cam adjusting mechanism 34 Coupling mechanism 36, 37 Clutch member 58 Cover member 71 Shielding wall 76 Elastic body 110 Paper feed control device DF Paper feed direction SH Corrugated cardboard sheet MT Main drive motor R1, R2, R3 area

Claims (10)

In the sheet feeding device that sends out the lowermost corrugated cardboard sheet among the plurality of laminated cardboard sheets in the sheet feeding direction toward the downstream processing device,
A plurality of paper feed rolls arranged in the paper feed direction and in contact with the lower surface of the cardboard sheet;
An elevating member configured to be movable up and down with respect to a plurality of paper feed rolls, bringing the cardboard sheets into contact with the plurality of paper feed rolls when lowered, and pulling the cardboard sheets away from the plurality of paper feed rolls when raised;
A suction mechanism for sucking the cardboard sheet downward in an area where a plurality of paper feed rolls are disposed;
The suction force of the suction mechanism acting on the corrugated cardboard sheet is regulated in an area in which some upstream paper feed rolls including the most upstream paper feed roll among the plurality of paper feed rolls are arranged. Suction regulation means;
And a control unit that controls operation and non-operation of the suction restricting unit according to the length of the corrugated cardboard sheet in the paper feeding direction when the order is changed. An adjustment mechanism for adjusting a lowering timing for lowering the elevating member and an elevating timing for raising the elevating member in a paper feeding period for sending out one cardboard sheet;
The control unit controls the adjustment mechanism so that the ascending timing is delayed according to the distance in the sheet feeding direction of the area where some upstream sheet feeding rolls are arranged when the suction regulating unit is operated. The paper feeder described in 1.   The controller activates the suction restricting means when the length of the cardboard sheet in the paper feeding direction is equal to or less than a predetermined sheet length, and the length of the cardboard sheet in the paper feeding direction The sheet feeding device according to claim 1 or 2, wherein the suction restricting means is inactivated when exceeding the above-mentioned length. A pair of feed rolls arranged downstream of the plurality of paper feed rolls in the paper feed direction, sandwiching the corrugated cardboard sheet and feeding it toward the downstream processing apparatus;
The sheet feeding according to claim 3, wherein the predetermined sheet length is determined based on a distance in a sheet feeding direction between a rotation center of the most upstream sheet feeding roll and a rotation center of the pair of feed rolls. apparatus. A rotation driving unit that applies a rotation driving force to a plurality of paper feed rolls;
A stopping means for stopping applying a rotational driving force to a part of the upstream side paper supply rolls among the plurality of paper supply rolls,
The stopping means stops applying the rotational driving force to a part of the upstream-side paper feed rolls when the length of the corrugated cardboard sheet in the paper feed direction is equal to or less than a predetermined sheet length. 5. The sheet feeding device according to claim 1, wherein a rotational driving force is allowed to be applied to a part of the upstream-side sheet feeding rolls when a length of the corrugated cardboard sheet exceeds a predetermined sheet length. Paper device.   The stopping means includes a blocking position for stopping the application of the rotational driving force to a part of the upstream paper feed rolls, and a connection position allowing the rotational driving force to be applied to a part of the upstream paper feed rolls. The sheet feeding device according to claim 5, further comprising a clutch mechanism configured to be switchable between the two. The suction regulating means includes a cover member that covers at least the most upstream paper feed roll among some of the upstream paper feed rolls,
The cover member is configured to be movable between an operating position that covers at least the most upstream paper feed roll at a position above the raised elevating member and an inoperative position that is retracted from some upstream paper feed rolls. The paper feeding device according to claim 1. The suction mechanism includes a suction chamber that houses a plurality of paper feed rolls, and a suction port that is formed in the suction chamber to suck air in the suction chamber.
The suction restricting means includes a separation wall that separates the suction chamber into a first space isolated from the suction port and a second space communicating with the suction port,
Among some upstream paper feed rolls, at least the most upstream paper feed roll is disposed in the first space,
The separation wall includes an operating position that separates the first space and a second space that is another space inside the suction chamber other than the first space, and an inoperative position that communicates the first space and the second space. The sheet feeding device according to claim 1, wherein the sheet feeding device is configured to be movable between the two. A suction mechanism that sucks the plurality of stacked cardboard sheets downward and a plurality of sheet feeding rolls arranged in the sheet feeding direction, and sucks the lowermost cardboard sheet among the stacked cardboard sheets. However, in the paper feeding device that feeds in the paper feeding direction toward the downstream processing device by a plurality of paper feed rolls,
Among the plurality of paper feed rolls, in a region where some upstream paper feed rolls including the most upstream paper feed roll in the paper feed direction are arranged, according to the length of the corrugated sheet in the paper feed direction, A paper feed control method for controlling an action of a suction force of a suction mechanism on a corrugated cardboard sheet and a regulation of the suction force. When the length of the corrugated cardboard sheet in the paper feeding direction exceeds a predetermined sheet length, the step of causing the suction force of the suction mechanism to act on the corrugated cardboard sheet in all regions where the plurality of paper feed rolls are disposed;
When the length of the corrugated cardboard sheet in the sheet feeding direction is equal to or less than a predetermined sheet length, among the plurality of sheet feeding rolls, a part of the upstream sheet feeding including the most upstream sheet feeding roll in the sheet feeding direction The sheet feeding control method according to claim 9, further comprising: regulating a suction force of a suction mechanism that acts on the cardboard sheet in an area where the paper roll is disposed.

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