Counter ejector and carton former

Abstract

A counter ejector (8) that is provided at the most downstream part of a carton former and that performs, in a hopper (8A), stacking, accumulating, counting, and discharging of corrugated cardboard sheets fed from a conveyance path in a prescribed conveyance direction, the counter ejector comprising: a buffer plate (10) that is formed of a plate-like member having deformable elasticity, is erected on the downstream side with respect to the hopper (8A), and has a surface part (11) that comes into contact with the front part of the corrugated cardboard sheet; a deformation device (20) that applies, to the buffer plate (10), a bending deformation that causes the surface part (11) to bulge toward the downstream side; a sensor (30) that is disposed upstream of the buffer plate (10) and detects conveyance information related to the corrugated cardboard sheet being conveyed; and a control device (40) that predicts, on the basis of the conveyance information, the timing at which the front part collides with the buffer plate (10) as a bending deformation start timing, and controls the operation of the deformation device (20) so as to apply a bending deformation to the buffer plate (10) at the predicted bending deformation start timing.

Description

Counter ejector and box manufacturing machine

[0001] This case relates to a counter ejector that accumulates and counts cardboard boxes in batches and discharges them, which is provided at the most downstream part of a box manufacturing machine, and a box manufacturing machine equipped with this counter ejector.

[0002] At the most downstream part of a box manufacturing machine that manufactures cardboard boxes, a counter ejector is installed to stack cardboard sheets (i.e., sheet-shaped cardboard boxes. Hereinafter, also simply referred to as "sheets") that are not yet assembled three-dimensionally in a hopper, accumulate and count them, and discharge them in batches of a predetermined number. A buffer plate (front stop) is provided on the downstream side in the conveying direction with respect to the hopper of this counter ejector, and the front part (the end part on the downstream side in the conveying direction) of the sheet sent out from the conveying path of the box manufacturing machine is made to collide (abut) with the buffer plate, so as to absorb the kinetic energy of the sheet and stop its movement.

[0003] For example, in Patent Document 1, in order to enhance the shock absorption performance when the sheet collides with the buffer plate, the buffer plate is formed of a flexible material, and the flexible material is passively elastically deformed by the collision force of the sheet, or the buffer plate is provided in an inclined state upward or downward, so as to suppress the rebound when the sheet collides. In this technology, the shock absorption performance and the rebound suppression performance are uniquely determined by mechanical settings.

[0004] Japanese Patent Application Laid-Open No. 2002-36399

[0005] However, in the structure where the inclination of the buffer plate is determined by mechanical settings as in the above Patent Document 1, and the flexible material forming the buffer plate is passively elastically deformed when the sheet collides, it is impossible to appropriately receive the sheets fed out sequentially, and the buffering effect of the buffer plate may become insufficient or excessive. In that case, it may cause the drawback that the sheets cannot be appropriately stacked in the hopper and jamming occurs.

[0006] Furthermore, in the past, from the perspective of suppressing the jamming described above, it has been known that operators have performed manual adjustment work as a technique separate from the technique of improving the cushioning performance of the cushioning plate. Adjustment work includes, for example, adjusting the amount and direction of air blown down from above the hopper to control the trajectory of the sheet's movement and the falling posture of the cushioning plate after impact. However, such adjustment work by operators relies heavily on the individual skill of the operator. In particular, the correlation between air blow adjustment and sheet behavior needs to be learned through experience. Therefore, depending on the operator's skill, it may be difficult to make appropriate adjustments according to the production conditions, and jamming may not be suppressed.

[0007] In other words, conventional technology had room for improvement in terms of enhancing the cushioning properties of the buffer plate, ensuring the accuracy of stacking sheets in the hopper, and improving productivity. Therefore, one of the objectives of the present invention is to ensure the accuracy of stacking sheets in the hopper and improve productivity by enhancing the cushioning properties of the buffer plate.

[0008] The counter ejector in this case is installed at the downstream end of a box-making machine and stacks corrugated cardboard sheets sent from the transport path of the box-making machine in a predetermined transport direction into a hopper, collects and counts them, and discharges them in batches. The counter ejector is made of a deformable, elastic plate-shaped member and is erected on the downstream side in the transport direction relative to the hopper. It includes a buffer plate having a surface that contacts the front part of the corrugated cardboard sheet sent from the transport path. A deformation device applies a bending deformation to the buffer plate such that the surface becomes convex toward the downstream side. A sensor is positioned upstream of the buffer plate in the transport direction and detects transport information regarding the corrugated cardboard sheet being transported along the transport path. A control device predicts the timing at which the front part collides with the buffer plate as the bending deformation start timing based on the transport information detected by the sensor, and controls the operation of the deformation device so as to apply the bending deformation to the buffer plate at the predicted bending deformation start timing.

[0009] The deformation device operates to apply bending deformation to the buffer plate in time with the moment the front of the corrugated cardboard sheet collides with the buffer plate, actively deforming the surface including the contact point of the front of the corrugated cardboard sheet into a curved surface that is convex toward the downstream side. As a result, the buffer plate can receive the front of the corrugated cardboard sheet with a surface that deforms to recede (escape, retreat) toward the downstream side as the front of the corrugated cardboard sheet moves in the transport direction. This mitigates and absorbs the impact caused by the front of the corrugated cardboard sheet colliding with the surface of the buffer plate, while also stopping the movement of the corrugated cardboard sheet.

[0010] In this way, by actively applying bending deformation to the cushioning plate while stopping the movement of the corrugated cardboard sheet, the rebound force applied from the cushioning plate to the corrugated cardboard sheet during a collision can be reduced. As a result, the rebound motion in which the corrugated cardboard sheet bounces back strongly from the cushioning plate is suppressed, and the falling posture of the corrugated cardboard sheet is less likely to be disrupted.

[0011] The counter-ejector in this invention enhances the cushioning performance of the cushioning plate by actively bending and deforming it upon impact with a corrugated cardboard sheet. Compared to conventional structures where the inclination of the cushioning plate is determined by mechanical settings or where the flexible material of the cushioning plate passively undergoes elastic deformation upon impact with a sheet, this design makes it easier to improve the cushioning performance of the cushioning plate with each impact of a corrugated cardboard sheet. Furthermore, since this counter-ejector can suppress disturbances in the drop posture without operator adjustments, it can suppress jam-ups regardless of the operator's skill level.

[0012] Furthermore, since this box-making machine is equipped with the counter-ejector described above, it is easier to improve the cushioning performance of the buffer plate each time a corrugated cardboard sheet collides with it, and jam-ups can be suppressed regardless of the operator's skill level.

[0013] According to this invention, by actively bending and deforming the cushioning plate when corrugated cardboard sheets collide, the cushioning performance of the cushioning plate can be enhanced, thereby ensuring the accuracy of stacking the sheets in the hopper and improving productivity.

[0014] This is a side view illustrating a counter-ejector according to an embodiment. This is an overall configuration diagram showing a box-making machine equipped with the counter-ejector of Figure 1. This is a side view showing the state in which bending deformation is applied to the buffer plate in the counter-ejector of Figure 1. (A) to (G) are schematic diagrams illustrating the transition of the deformation state of the buffer plate in the counter-ejector of Figure 1. (A) to (D) are explanatory diagrams illustrating the adjustment of the amount of bending deformation. (A) and (B) are side views illustrating a counter-ejector according to the first modified example. (A) and (B) are side views illustrating a counter-ejector according to the second modified example. (A) and (B) are side views illustrating a counter-ejector according to the third modified example. (A) and (B) are side views illustrating a counter-ejector according to the fourth modified example. (A) and (B) are side views illustrating a counter-ejector according to the fifth modified example. (A) and (B) are side views illustrating a counter-ejector according to the sixth modified example. (A) and (B) are side views illustrating a modified example relating to a link mechanism. (A) and (B) are side views illustrating modified versions of the link mechanism.

[0015] The following describes a counter-ejector and a box-making machine equipped with a counter-ejector as embodiments, with reference to the drawings. The following embodiments are merely illustrative, and there is no intention to exclude various modifications and applications of technologies not explicitly shown in these embodiments. Each configuration of the following embodiments can be modified in various ways without departing from their spirit. They can also be selected or combined as needed. The directions used in the following description are defined as follows, based on the counter-ejector and box-making machine mounted on a horizontal surface. The direction in which the corrugated cardboard sheet is conveyed in the box-making machine is called the conveying direction MD. The direction that intersects the conveying direction MD along the surface of the sheet being conveyed in the conveying direction MD is called the intersecting direction CD. Here, the intersecting direction CD is the direction perpendicular to the conveying direction MD and corresponds to the machine width direction of the box-making machine or the width direction of the sheet.

[0016] Unless otherwise specified, "upstream" refers to the upstream direction in the transport direction MD, and similarly, unless otherwise specified, "downstream" refers to the downstream direction in the transport direction MD. Unless otherwise specified, "up" and "down" refer to the vertical up and down directions in the box-making machine and corrugating machine. The up and down directions are perpendicular to the transport direction MD and the intersecting direction CD. The intersecting direction CD is not shown in the diagram.

[0017] [1. Configuration] Figure 1 is a side view showing a part of the counter-ejector 8 according to the present invention. This counter-ejector 8 is provided at the downstream end of the box-making machine 1 shown in Figure 2. First, the configuration of the box-making machine 1 will be explained with reference to Figure 2. The box-making machine 1 shown in Figure 2 is a device that manufactures corrugated cardboard sheets 2 by applying processing such as printing, grooving, scoring, punching, gluing, and folding to the box-making sheet material 2A, which is the object to be processed. The box-making sheet material 2A is a rectangular plate-shaped sheet that is manufactured by a corrugating machine (not shown) and formed to the size of one box. The corrugated cardboard sheet 2 (hereinafter also simply referred to as "sheet") is a sheet-shaped corrugated cardboard box in which the above processing has been applied to the box-making sheet material 2A, and it is not assembled in a three-dimensional shape but is folded into a rectangular flat shape. In contrast, the box-making sheet material 2A is a rectangular plate-shaped sheet that has not undergone the above processing and is simply formed to the size of one box.

[0018] Figure 2 shows an example where the box-making machine 1 manufactures a sheet 2 that becomes a so-called A-type corrugated cardboard box. The process by which the box-making sheet material 2A is processed into sheet 2 is shown above the equipment configuration of each step in the box-making machine 1, separately from the equipment configuration and corresponding to the equipment configuration. In the box-making machine 1, the box-making sheet material 2A is transported in the transport direction MD with one of its long sides facing downstream in the transport direction MD. This position ensures that the corrugations (flutes) of the box-making sheet material 2A are parallel to the transport direction MD.

[0019] The box-making machine 1 is equipped with, in order from the upstream side, a paper feeding unit 3, a printing unit 4, a paper discharge unit 5, a die cutter 6, a folder gluer 7, and a counter ejector 8. In the box-making machine 1, the sheet material 2A for box making is transported along the transport direction MD in a transport path 9 that extends from the upstream side to the downstream side, and is processed into sheets 2 by the above-mentioned devices 3 to 7, and then sent to the counter ejector 8. That is, the transport path 9 transports the sheet material 2A for box making in the area where devices 3 to 7 are installed, and transports the sheets 2 in the area from the downstream side of the folder gluer 7 to the counter ejector 8. The transport speed of the sheet material 2A and the sheets 2 in the transport path 9 is set appropriately according to the processing capacity and production order of the box-making machine 1, and can be set to a high speed, for example, to discharge several hundred sheets 2 per minute.

[0020] The paper feeding unit 3 is a unit that supplies (feeds) the box-making sheet material 2A to the printing unit 4. The paper feeding unit 3 is brought in with a large number of sheet-shaped box-making sheet materials 2A stacked on top of each other. The paper feeding unit 3 supplies these box-making sheet materials 2A one by one to the printing unit 4. The printing unit 4 includes a flexographic printing unit with a predetermined number of colors (in this case, four colors) and prints patterns such as images and text onto the box-making sheet materials 2A.

[0021] The paper discharge unit 5 cuts grooves and lines into the box-making sheet material 2A printed in the printing unit 4 and then discharges it. The die cutter 6 performs die-cutting, further groove cutting, and line cutting on the box-making sheet material 2A discharged from the paper discharge unit 5. The folder gluer 7 applies glue to the adhesive margin formed at one end of the box-making sheet material 2A in the width direction (crossing direction CD) processed by the die cutter 6, and then folds the box-making sheet material 2A so that both ends in the width direction of the box-making sheet material 2A overlap.

[0022] The sheet material 2A for box making, processed by the folder gluer 7, is bonded at both ends in the width direction with adhesive to form a sheet 2. The counter ejector 8 stacks the sheets 2 processed by the folder gluer 7 into a hopper 8A (part of which is shown by a dashed line in Figure 1), counts them, and discharges them as a batch 2B. A batch 2B is a bundle of sheets 2 stacked in predetermined quantities by the counter ejector 8. Sheets 2 are shipped in batches 2B as one unit. In a batch 2B, multiple sheets 2 are stacked vertically with all four sides aligned.

[0023] The counter ejector 8 has the function of reducing (stopping) the transport speed of the sheets 2 sent from the folder gluer 7 to zero, and dropping the sheets 2 into the hopper 8A for stacking. In addition, the counter ejector 8 has the function of counting the multiple sheets 2 stacked in the hopper 8A, and the discharge function of discharging the sheets 2 in batches 2B once a predetermined number of sheets have been stacked.

[0024] In the counter ejector 8, a buffer plate 10 made of a deformable, elastic plate-shaped member is erected on the downstream side of the conveying direction MD relative to the hopper 8A. The buffer plate 10 is a plate-shaped member that acts as a stopper to stop the sheet 2 being fed out from the folder gluer 7. Deformable elasticity means that, as shown in Figures 1 and 3, the surface portion 11 of the buffer plate 10 can be bent by bending deformation applied by a deformation device 20, which will be described later. As shown in Figure 2, the hopper 8A is located downstream and below the discharge port 9A, which is the end of the conveying path 9. The buffer plate 10 is erected downstream of the hopper 8A when viewed from the discharge port 9A, and the hopper 8A can be said to be located upstream of the buffer plate 10.

[0025] Figure 1 is a side view of the main part of the counter ejector 8, showing only a portion including the buffer plate 10, with other parts omitted. As shown in Figures 1 and 2, the buffer plate 10 has a surface portion 11 that contacts the front portion 2F (see Figure 3) of the sheet 2 that is fed out from the discharge port 9A (conveyor path 9). The surface portion 11 is a part of the buffer plate 10 and is a planar region provided facing the discharge port 9A. This surface portion 11 is the part that contacts the front portion 2F (see Figure 3) of the sheet 2 that is conveyed from the discharge port 9A and receives the sheet 2. The front portion 2F (see Figure 3) of the sheet 2 is the leading edge (edge) located on the downstream side of the sheet 2 during conveyance.

[0026] The buffer plate 10 is positioned on the counter ejector 8 with its surface portion 11 extending in the vertical direction and the intersecting direction CD (i.e., intersecting the transport direction MD), and spaced downstream of the discharge port 9A. A hopper 8A is provided to surround the space between the buffer plate 10 and the discharge port 9A. The buffer plate 10 is provided in an inclined position with its upper part tilted downstream, as described in the above-mentioned Patent Document 1, from the viewpoint of suppressing the repulsive force when the front portion 2F (see Figure 3) of the sheet 2 collides with it.

[0027] Specifically, as the buffer plate 10 in this embodiment, a laminated plate can be applied, which is made by stacking multiple laminates (in this case, three) in the transport direction MD, with the laminates being made of hard rubber elastic plates and leaf springs made of metal materials such as steel. The elastic plates of the laminated plate are provided on the surface portion 11. That is, the laminated plate is set so that the elastic plates are located on the upstream side in the transport direction MD. As a result, the buffer plate 10 can absorb and mitigate the impact when the sheet 2 collides with it, also through the elasticity of the elastic plates themselves. Furthermore, in the laminated plate, the laminates are not bonded to each other and may be stacked with a small gap between them. Such a laminated plate can be made using a well-known structure. Moreover, the buffer plate 10 is not limited to a laminated plate, as long as it is a plate-shaped member with deformationable elasticity.

[0028] As shown in Figure 1, the buffer plate 10 is supported at its upper end by an upper support member 12U and at its lower end by a lower support member 12L. The upper support member 12U and the lower support member 12L are attached to the frame 13 of the counter ejector 8 so as to mount the buffer plate 10 in a predetermined position and orientation on the counter ejector 8. The upper and lower ends of the buffer plate 10 are fixed to the upper support member 12U and the lower support member 12L, respectively, for example by screws. Below the buffer plate 10, a plate 14, which is a separate component from the buffer plate 10, is provided. The plate 14 is a component that forms the downstream wall surface of the hopper 8A and may be formed from a deformable, non-elastic plate-shaped member.

[0029] The counter-ejector 8 includes the buffer plate 10 described above, as well as a deformation device 20, a sensor 30, and a control device 40. The deformation device 20 is a device that applies a bending deformation to the buffer plate 10 such that the surface portion 11 becomes convex toward the downstream side. The deformation device 20 is a mechanical element that includes a drive element for transmitting the force for bending deformation and a driven element which is the element to which the force from the drive element is transmitted and which applies bending deformation to the buffer plate 10. Here, bending deformation means bending the buffer plate 10 so as to displace the region of the surface portion 11 that includes the contact point 11P where the front portion 2F of the sheet 2 (see Figure 3) makes contact toward the downstream side.

[0030] The deformation device 20 in Figure 1 is configured as a tensile deformation mechanism 20A that applies bending deformation to the buffer plate 10 by pulling it downstream from the back surface 11A opposite to the front surface 11. This tensile deformation mechanism 20A includes a cam (hereinafter also referred to as "eccentric cam") 21 that rotates around a rotation axis 21A along the intersecting direction CD (the machine width direction of the box-making machine 1), and a driven member 22 connected to the back surface 11A of the buffer plate 10. The eccentric cam 21 is an example of the above-mentioned drive element, and the driven member 22 is an example of the above-mentioned driven element.

[0031] The driven member 22 in Figure 1 is a bracket with a U-shaped cross-sectional (side) shape when viewed from the intersecting direction CD, and is made of a rigid member such as steel. The driven member 22 is attached to a mounting base 15 fixed to the frame 13 of the counter ejector 8 so as to be able to reciprocate on both sides in the transport direction MD, and its inner wall surface 23 is positioned to be in contact with the outer circumference of the eccentric cam 21. The vertical surface 24 on the upstream side of the outer wall surface of the driven member 22 is connected to the back surface 11A of the buffer plate 10. Any means can be used to connect (fix) the driven member 22 and the back surface 11A so as not to separate the two members, such as welding, bonding, or bolting. From the viewpoint of reducing the repulsive force (impact) when the front part 2F of the sheet 2 (see Figure 3) collides, it is preferable that the connection point between the driven member 22 and the back surface 11A be set on the back surface of the area including the contact point 11P that the front part 2F of the sheet 2 (see Figure 3) contacts during a collision.

[0032] The eccentric cam 21 has a circular shape when viewed from the axial direction (intersecting direction CD) of the rotation axis 21A. The position of the rotation axis 21A is set to be offset from the center of the circle, and the radial dimension from the rotation axis 21A to the outer circumference is not constant. The rotation axis 21A of the eccentric cam 21 is connected to an actuator (not shown), and the eccentric cam 21 rotates around the rotation axis 21A when driven by the actuator. The tensile deformation mechanism 20A is configured such that, in response to the rotation of the eccentric cam 21, the driven member 22 moves downstream, thereby displacing the portion of the back surface 11A connected to the driven member 22 downstream. As a result, the tensile deformation mechanism 20A is configured to pull the buffer plate 10 downstream and apply bending deformation.

[0033] Figure 1 shows the buffer plate 10 in a non-bent state, before bending deformation is applied by the tensile deformation mechanism 20A. Figure 3 shows the buffer plate 10 in a bent state, after bending deformation is applied by the tensile deformation mechanism 20A. The bent state shown in Figure 3 represents the maximum amount of bending deformation applied to the buffer plate 10 in the non-bent state shown in Figure 1, and no further bending deformation can be applied. As shown in Figure 3, in the bent state, in accordance with the rotation of the eccentric cam 21, the portion of the back surface 11A connected to the driven member 22 is displaced downstream compared to the back surface 11A in the non-bent state shown in Figure 1 (shown by the dashed line in Figure 3). As a result, the buffer plate 10 is deformed into a curved surface in which a part of the surface 11 is convex toward the downstream side. In other words, the buffer plate 10 in the bent state can be said to be deformed into a curved surface in which a part of the surface 11 is concave toward the downstream side, as viewed from the sheet 2 moving downstream.

[0034] The tensile deformation mechanism 20A operates in a cycle that deforms the buffer plate 10 from the non-bent deformation state in Figure 1 to the bent deformation state in Figure 3, and then returns it from the bent deformation state in Figure 3 to the non-bent deformation state in Figure 1. In this embodiment, the tensile deformation mechanism 20A is configured to perform one cycle of deformation of the buffer plate 10 each time the eccentric cam 21 is rotated once in a predetermined rotational direction. The amount of protrusion of the eccentric cam 21 toward the buffer plate 10 changes according to the rotational phase. In this case, when the eccentric cam 21 rotates half a turn (180° from the initial position) from the initial position where the buffer plate 10 is in a non-bent deformation state (the position where the amount of protrusion of the eccentric cam 21 toward the buffer plate 10 is maximum), the amount of protrusion of the eccentric cam 21 toward the buffer plate 10 is minimum, and the buffer plate 10 is in a maximum bent deformation state. When it rotates another half turn (360° from the initial position), the buffer plate 10 returns to the non-bent deformation state. The size and shape of the eccentric cam 21 and the position of the rotation axis 21A are set appropriately so that the deformation of the buffer plate 10 is completed in one cycle for each rotation of the eccentric cam 21.

[0035] The sensor 30 and the control device 40 are electrical components for controlling the operation of the tensile deformation mechanism 20A (deformation device 20). The sensor 30 is positioned upstream of the buffer plate 10 in the transport direction MD and detects transport information regarding the sheet 2 as it is being transported along the transport path 9 (see Figure 1). The transport information is used by the control device 40, which will be described later, to control the operation of the tensile deformation mechanism 20A (deformation device 20), and includes, for example, the position of the sheet 2 in the transport path 9 and the transport speed of the sheet 2 in the transport path 9.

[0036] The sensor 30 in Figure 1 includes a position sensor 31 for detecting the position of the sheet 2 on the transport path 9 and a speed sensor 32 for detecting the transport speed of the sheet 2. However, the sensor 30 may consist of only one of the position sensor 31 or the speed sensor 32. Furthermore, the position sensor 31 may include not only a sensor that identifies the position of the sheet 2 on the transport path 9, but also a sensor that detects whether or not the sheet 2 has passed a predetermined point on the transport path 9. Any well-known and suitable sensors may be used for the position sensor 31 and the speed sensor 32. In the following description, when it is not necessary to distinguish between the position sensor 31 and the speed sensor 32, they will be collectively referred to as sensor 30.

[0037] The sensors 30 (31 and 32) can be placed at any one or more locations on the transport path 9 located upstream of the buffer plate 10 in the transport direction MD. When sensors 30 are provided at multiple locations, both the position sensor 31 and the speed sensor 32 may be provided at all of the multiple locations, or at least one of the position sensor 31 and speed sensor 32 may be provided at at least one other location, and the other of the position sensor 31 and speed sensor 32 may be provided at at least one other location. For example, Figure 2 shows an example in which sensors 30 are provided at two locations: upstream of the discharge port 9A inside the counter ejector 8 and inside the folder gluer 7 (i.e., upstream of the counter ejector 8). The sensor 30 provided upstream of the counter ejector 8 detects transport information of the box-making sheet material 2A. In this specification, the expression that the counter-ejector 8 is equipped with a sensor 30 also includes, as described above, a configuration in which the sensor 30 (detection element of the sensor 30) is provided in the folder gluer 7 upstream of the counter-ejector 8, and the detection signal is used by the counter-ejector 8. The location of the sensor 30 upstream of the counter-ejector 8 can be set, for example, approximately 1 m upstream of the counter-ejector 8.

[0038] The control device 40 is an electronic control device that controls the operation of the tensile deformation mechanism 20A (deformation device 20), and is configured as an LSI device or embedded electronic device that integrates a microprocessor, ROM, RAM, etc. The control device 40 may be configured as part of the production management device (not shown) of the box-making machine 1, or it may be configured as a device independent of the production management device (not shown). The control device 40 can perform the function of controlling the operation of the tensile deformation mechanism 20A (deformation device 20) by executing a software program stored in the memory device.

[0039] A sensor 30 is connected to the input side of the control device 40, and an actuator (not shown) of the tensile deformation mechanism 20A (deformation device 20) is connected to the output side of the control device 40. The control by this control device 40 predicts the timing at which the front part 2F (see Figure 3) of the sheet 2 collides with the buffer plate 10 as the start of bending deformation based on the transport information detected by the sensor 30, and controls the operation of the tensile deformation mechanism 20A so as to apply bending deformation to the buffer plate 10 at the predicted bending deformation start timing.

[0040] Specifically, the control device 40 controls the bending deformation start timing and bending deformation speed of the tensile deformation mechanism 20A based on the transport information. The bending deformation speed is the speed at which the front part 2F (see Figure 3) of the sheet 2 on the surface 11 is displaced downstream, and represents the speed at which it is displaced from a non-bent deformation state (see Figure 1) to a bent deformation state (see Figure 3). This bending deformation speed corresponds to the rotational speed when the eccentric cam 21 is rotated from a non-bent deformation state (see Figure 1) to a bent deformation state (see Figure 3).

[0041] As functional elements for implementing the above control, the control device 40 includes a timing prediction unit 41 and an operation control unit 42. The timing prediction unit 41 predicts the timing at which the front portion 2F of the sheet 2 collides with the surface portion 11 of the buffer plate 10, based on the transport information (transport speed and position) detected by the sensor 30. Timing prediction based on transport information can be achieved by well-known technology.

[0042] The operation control unit 42 generates an instruction signal to instruct the operation of the actuator (not shown) of the tensile deformation mechanism 20A based on the timing predicted by the timing prediction unit 41, and outputs the instruction signal to the actuator (not shown). Specifically, the operation control unit 42 generates an instruction signal to instruct the bending deformation start timing and bending deformation speed in the tensile deformation mechanism 20A, and outputs it to the actuator (not shown) of the tensile deformation mechanism 20A.

[0043] The bending deformation start timing is set at the timing when the sheet 2 collides (contacts) with the face portion 11, or at the timing immediately before the sheet 2 collides (contacts) with the face portion 11, from the viewpoint of reducing the impact or repulsive force when the sheet 2 collides with the face portion 11 of the buffer plate 10. The bending deformation speed is set to a speed slower than the moving speed of the front portion 2F of the sheet 2 from the viewpoint of causing the front portion 2F of the sheet 2 to collide (contact) with the face portion 11 while bending the buffer plate 10 to stop the movement of the sheet 2. The moving speed of the front portion 2F of the sheet 2 is the speed at which the front portion 2F of the sheet 2 moves downstream in the conveyance direction MD immediately before the front portion 2F of the sheet 2 collides with the buffer plate 10. The moving speed can be calculated (predicted) based on the conveyance information detected by the sensor 30.

[0044] By making the bending deformation speed slower than the moving speed, it is possible to cause the front portion 2F of the sheet 2 to collide (contact) with the face portion 11 while bending the buffer plate 10. If the bending deformation speed is too slow compared to the moving speed, it is considered that the repulsive force when the sheet 2 collides (contacts) with the face portion 11 cannot be sufficiently reduced. Therefore, the bending deformation speed is set to an appropriate speed that can sufficiently suppress the impact or repulsive force caused by the collision of the sheet 2 and receive the front portion 2F of the sheet 2 at the face portion 11 (contact the face portion 11) to stop the movement of the sheet 2.

[0045] The moving speed of the front portion 2F of the sheet 2 gradually attenuates to zero (stops) after colliding (contacting) with the face portion 11. Therefore, it is preferable that the bending deformation speed is set to decelerate and change so that the front portion 2F of the sheet 2 contacts the face portion 11 of the buffer plate 10 from immediately after the sheet 2 collides with the buffer plate 10 until the movement stops, and becomes zero when the movement of the sheet 2 stops. Note that the bending deformation speed corresponds to the rotational speed when the eccentric cam 21 is rotated 180° from the initial position in the non-bending deformed state (FIG. 1) to the bending deformed state (FIG. 3). Therefore, the bending deformation speed becomes zero when the eccentric cam 21 is rotated 180° from the initial position. The deceleration change curve of the bending deformation speed can be predicted by the operation control unit 42 based on production conditions including the conveyance speed, weight, rigidity, etc. of the sheet 2, or can be preset based on simulations or experiments.

[0046] Further, the operation control unit 42 also performs return control to return the buffer plate 10 from the bent deformation state (FIG. 3) to the non-bent deformation state (FIG. 1). Specifically, the return control is control to end the bending deformation by the tensile deformation mechanism 20A when the sheet 2 stops moving, and to return from the bent deformation state to the non-bent deformation state. In other words, the return control of the operation control unit 42 is control to cause the eccentric cam 21 to reach the half-rotation position (see FIG. 3) rotated 180° from the initial position when the sheet 2 stops moving, and to rotate the eccentric cam 21 180° from the half-rotation position.

[0047] Here, the time point when the sheet 2 stops moving can be predicted by the operation control unit 42 from conveyance information, the timing when the sheet 2 collides (contacts) with the face portion 11, and the like. The operation control unit 42 can set (predict) the time point when the sheet 2 stops moving as the bending deformation end timing. Further, the operation control unit 42 may regard the time point when the eccentric cam 21 is rotated 180° as the time point when the bending deformation ends without predicting the time point when the sheet 2 stops moving (bending deformation end timing). In the return control, when the bending deformation by the tensile deformation mechanism 20A ends, in other words, when the eccentric cam 21 is rotated 180° from the initial position, the return speed until returning to the non-bent deformation state is controlled.

[0048] The return speed is set to an appropriate speed at which the sheet 2 can return to the non-bent deformation state without contacting (interfering) with the buffer plate 10 when it stops moving and falls into the hopper 8A, and before the subsequent sheet 2 collides with the buffer plate 10. The bending deformation end timing and the return speed can be preset based on simulation and experiments based on production conditions including the conveyance speed, weight, rigidity, etc. of the sheet 2. This return speed corresponds to the rotation speed when rotating the eccentric cam 21 from the bent deformation state (FIG. 3) to the non-bent deformation state (FIG. 1).

[0049] The control device 40 controls the operation of the tensile deformation mechanism 20A each time a sheet 2 is fed from the transport path 9 to the counter ejector 8. Since the sheets 2 are fed one by one from the transport path 9 to the counter ejector 8, the control device 40 controls the operation of the tensile deformation mechanism 20A each time a sheet 2 is fed. Specifically, the eccentric cam 21 is rotated once each time a sheet 2 is fed. Since multiple sheets 2 are fed sequentially from the transport path 9, the control device 40 repeatedly controls the operation of the tensile deformation mechanism 20A iteratively (continuously) in accordance with the sequential feeding of multiple sheets 2. As described above, the transport speed of the sheets 2 in the transport path 9 can be set to a high speed, for example, to discharge several hundred sheets 2 per minute. Therefore, the control device 40 controls the operation of the tensile deformation mechanism 20A in high-speed operation, for example, processing several hundred sheets 2 per minute.

[0050] Figures 4(A) to 4(G) are explanatory diagrams of the state transitions of the tensile deformation mechanism 20A from when a single sheet 2 moves toward the buffer plate 10 until it stops moving and falls. The state transitions of the tensile deformation mechanism 20A shown in Figures 4(A) to 4(G) are given as an example when the bending deformation start timing is set to the timing when the sheet 2 collides (contacts) with the surface portion 11. Figures 4(A) to 4(D) show the state transitions from when a single sheet 2 moves toward the buffer plate 10 until it stops moving. At this time, the buffer plate 10 changes from a non-bent deformation state (Figure 1) to a bent deformation state (Figure 3).

[0051] Figure 4(A) shows the state before the front portion 2F of the sheet 2 contacts the surface portion 11 (the non-bending deformation state shown in Figure 1). At this point, the sensor 30 has detected the transport information of the sheet 2, so the control device 40 can generate an instruction signal to the tensile deformation mechanism 20A based on this transport information. Figure 4(B) shows the state when the front portion 2F contacts (collides with) the surface portion 11. At this timing, the tensile deformation mechanism 20A starts operating based on the instruction signal from the control device 40.

[0052] As shown in Figure 4(C), the buffer plate 10 is bent and deformed at a bending deformation speed slower than the moving speed, while the surface portion 11 supports the front portion 2F. Since the front portion 2F is in contact with the surface portion 11, the moving speed of the sheet 2 gradually decreases. At this time, the contact point 11P of the surface portion 11 that contacts the front portion 2F is displaced downstream, so the repulsive force on the front portion 2F is suppressed. Figure 4(D) shows the state in which the amount of deformation of the buffer plate 10 is at its maximum (the bending deformation state shown in Figure 3). At this point, the sheet 2 stops moving. Also, the eccentric cam 21 has rotated 180° from the initial position shown in Figure 4(A).

[0053] Figures 4(E) to 4(G) show the state transitions from when one sheet 2 stops moving until it falls into the hopper 8A and the subsequent sheet 2' is fed out. At this time, the buffer plate 10 changes (returns) from a bent deformation state (Figure 3) to a non-bent deformation state (Figure 1). Figure 4(E) shows the buffer plate 10 beginning to return from the bent deformation state. When the eccentric cam 21 rotates further from the 180° rotation position shown in Figure 4(D), the surface portion 11 begins to return to the upstream side. At this time, the sheet 2 has stopped moving and is pushed back to the upstream side by the surface portion 11.

[0054] Figure 4(F) shows the state in which the eccentric cam 21 returns to the initial position shown in Figure 4(A), and the buffer plate 10 returns to a non-bent deformation state. The buffer plate 10 is no longer subjected to bending deformation and has returned to a flat plate shape. Since there is no more pushback from the surface portion 11, the sheet 2 moves away from the surface portion 11 upstream and falls downward. Then, as shown in Figure 4(G), the sheet 2 falls into the hopper 8A, while the subsequent sheet 2' moves toward the buffer plate 10. From here on, the operation cycle of the tensile deformation mechanism 20A is repeated in the order of Figures 4(A) to (G).

[0055] Here, the amount of deformation due to bending deformation by the tensile deformation mechanism 20A will be explained. The amount of bending deformation is the amount by which the contact point 11P, to which the front part 2F of the surface part 11 makes contact, is displaced downstream when the buffer plate 10 changes from a non-bent deformation state (Figure 1) to a bent deformation state (Figure 3). The amount of bending deformation is maximum in the bent deformation state shown in Figure 3. The appropriate amount of bending deformation may vary depending on the sheet production conditions such as the weight, rigidity, size, shape, and conveying speed of the sheet 2. For this reason, the tensile deformation mechanism 20A (deformation device 20) is configured to allow adjustment of the amount of bending deformation. Specifically, the eccentric cam 21 of the tensile deformation mechanism 20A (deformation device 20) is configured to be interchangeable between a first cam 21X set to a certain amount of deformation and a second cam 21Y set to a different amount of deformation. By changing the first cam 21X and the second cam 21Y according to the production conditions, the amount of bending deformation can be appropriately set.

[0056] Figures 5(A) and 5(B) are schematic diagrams illustrating a first cam 21X with a certain deformation amount X and a second cam 21Y with a different deformation amount Y. In Figures 5(A) and 5(B), the cams 21X and 21Y in the non-bending deformation state are shown by solid lines, and the cams 21X and 21Y in the bending deformation state are shown by dashed lines. The dashed-dotted line represents a part of the elevation surface 24 of the driven member 22 (see Figure 1) in the non-bending deformation state, and the dashed-dotted line represents a part of the elevation surface 24 in the bending deformation state.

[0057] As shown in Figures 5(A) and (B), in the tensile deformation mechanism 20A described above, the deformation amounts X and Y are determined by the position of the rotation axis 21A in the eccentric cams 21X and 21Y. Specifically, the further the rotation axis 21A is set downstream from the center point O of the circle along the outer circumference in the initial position (non-bending deformation state), the larger the deformation amount. Conversely, the closer the rotation axis 21A is set to the center point O, the smaller the deformation amount. In Figures 5(A) and (B), the rotation axis 21A of the eccentric cam 21X is set further downstream from the center point O than the rotation axis 21A of the eccentric cam 21Y. Therefore, the deformation amount X of the eccentric cam 21X is set to be larger than the deformation amount Y of the eccentric cam 21Y.

[0058] As another example of adjusting the amount of bending deformation, the control device 40 shown in Figure 1 may have an adjustment unit 43 for adjusting the amount of bending deformation. The adjustment unit 43 is a functional part that adjusts the amount of bending deformation. Specifically, the adjustment unit 43 of the control device 40 controls the rotation angle (phase) of the eccentric cam 21 of the tensile deformation mechanism 20A. Figures 5(C) and 5(D) are explanatory diagrams that adjust the amount of bending deformation by controlling the rotation direction and / or rotation angle (phase) of the eccentric cam 21. In the tensile deformation mechanism 20A described above, as shown in Figure 5(C), the eccentric cam 21 is rotated 180° from the non-bending deformation state (initial state with a rotation angle of 0°) shown by the solid line to the non-bending state shown by the dashed line. This can be said to be that the control device 40 switches between the bending deformation state and the non-bending deformation state by controlling the rotation of the eccentric cam 21 within an angular range of 180°. Let the amount of deformation in this case be "XA".

[0059] In contrast to the configuration in Figure 5(C) where the eccentric cam 21 is controlled to rotate 180°, Figure 5(D) shows a configuration in which the eccentric cam 21 is rotated 90° from the non-bending deformation state (initial state with a rotation angle of 0°) shown by the solid line to the bending deformation state shown by the dashed line. In other words, the bending deformation state and the non-bending deformation state are switched by rotating the eccentric cam 21 within a 90° angular range. In this case, the deformation amount XB is smaller than the deformation amount XA. Thus, the deformation amount of the bending deformation can also be set by adjusting the angular range in which the eccentric cam 21 is rotated. Note that in the configuration in Figure 5(D) where the bending deformation state and the non-bending deformation state are switched within a narrow angular range, the operation cycle between the bending deformation state and the non-bending deformation state may be repeated by repeatedly rotating the eccentric cam 21 in the forward and reverse directions.

[0060] [2. Effects] The counter-ejector 8 according to this embodiment, as described above, is configured as described above and therefore has the following effects. The tensile deformation mechanism 20A operates to apply bending deformation to the buffer plate 10 in time with the timing when the front part 2F of the sheet 2 collides with the buffer plate 10, thereby actively deforming the surface portion 11, including the contact point 11P where the front part 2F of the sheet 2 contacts, into a curved surface that is convex toward the downstream side. As a result, the front part 2F of the sheet 2 moving in the transport direction MD can be received by the surface portion 11 which deforms to be concave (escape, recede) toward the downstream side. This makes it possible to stop the movement of the sheet 2 while mitigating and absorbing the impact caused by the front part 2F of the sheet 2 colliding with the surface portion 11.

[0061] By actively applying bending deformation to the cushioning plate 10 while stopping the movement of the sheet 2, the rebound force applied from the cushioning plate 10 to the sheet 2 during a collision can be reduced. As a result, the movement of the sheet 2 bouncing back significantly from the cushioning plate 10 is suppressed, and the falling posture of the sheet 2 becomes less likely to be disturbed.

[0062] The cushioning performance of the cushioning plate 10 is enhanced by a configuration that actively bends and deforms the cushioning plate 10 when the sheet 2 collides with it. Compared to conventional structures where the inclination of the cushioning plate is determined by mechanical settings or where the flexible material of the cushioning plate passively undergoes elastic deformation when the sheet 2 collides with it, it is easier to enhance the cushioning performance of the cushioning plate 10 each time the sheet 2 collides with it. Furthermore, since disturbances in the falling posture are suppressed regardless of the operator's adjustment work, disturbances in the falling posture of the sheet 2 can be suppressed regardless of the operator's skill. As described above, with the counter ejector 8 of this embodiment and the box-making machine 1 equipped with the counter ejector 8, the cushioning performance of the cushioning plate 10 is enhanced by a configuration that actively bends and deforms the cushioning plate 10 when the sheet 2 collides with it, thereby ensuring the accuracy of stacking the sheets 2 in the hopper 8A and improving productivity. Accuracy in stacking the sheets 2 in the hopper 8A can be ensured, and jamming in the hopper 8A can be prevented.

[0063] The tensile deformation mechanism 20A preferably applies bending deformation to the buffer plate 10 by pulling it downstream from the back surface 11A opposite to the surface 11. Specifically, the tensile deformation mechanism 20A preferably includes an eccentric cam 21 that rotates around a rotation axis 21A along the machine width direction of the box-making machine 1, and a driven member 22 that is connected to the back surface 11A of the buffer plate 10 and applies bending deformation to the buffer plate 10 in accordance with the rotation of the eccentric cam 21. This makes it possible to effectively deform the surface 11 including the contact point 11P that the sheet 2 contacts when the sheet 2 collides.

[0064] Preferably, the control device 40 controls the operation of the tensile deformation mechanism 20A each time a sheet 2 is fed out from the transport path 9. This allows the control device 40 to bend and deform the buffer plate 10 each time a sheet 2 collides with the buffer plate 10. Preferably, the control device 40 controls the timing of the start of bending deformation of the tensile deformation mechanism 20A and the bending deformation speed of the contact point 11P on the surface portion 11 where the front portion 2F of the sheet 2 makes contact. This allows the surface portion 11, including the contact point 11P that the sheet 2 contacts when it collides, to be deformed more effectively.

[0065] Furthermore, it is preferable that the control device 40 controls the timing of the start of bending deformation based on the transport information so that bending deformation by the tensile deformation mechanism 20A starts just before the front portion 2F of the sheet 2 collides with the buffer plate 10, and controls the bending deformation speed to a speed slower than the movement speed of the front portion 2F of the sheet 2 just before it collides with the buffer plate 10. Alternatively, it is preferable that the control device 40 controls the timing of the start of bending deformation based on the transport information so that bending deformation by the tensile deformation mechanism 20A starts when the front portion 2F of the sheet 2 collides with the buffer plate 10, and controls the bending deformation speed to a speed slower than the movement speed of the front portion 2F of the sheet 2 just before it collides with the buffer plate 10. As a result, the buffer plate 10 can receive the front portion 2F of the sheet 2 while displacing its surface portion 11, thereby further enhancing its cushioning ability.

[0066] Furthermore, it is preferable that the control device 40 controls the bending deformation speed so that it decelerates in accordance with the deceleration change from immediately after the sheet 2 collides with the buffer plate 10 until it stops moving. This allows the buffer plate 10 to more effectively stop the sheet 2 while suppressing the repulsive force of the sheet 2 by the displacement of the surface portion 11, thereby further enhancing its cushioning performance. It is also preferable that the control device 40 controls the return speed of the buffer plate 10 from the bent deformation state to the non-bent deformation state when the bending deformation by the tensile deformation mechanism 20A is completed. This makes it less likely for the sheet 2 to come into contact (interfere) with the buffer plate 10, which is in the process of returning to the non-bent deformation state, when the sheet 2 stops moving and falls into the hopper 8A. As a result, the sheet 2 can be dropped into the hopper 8A in an appropriate posture. Furthermore, it is preferable that the control device 40 predicts the timing when the front portion 2F of the sheet 2 that collides with the buffer plate 10 stops moving as the bending deformation end timing based on the transport information, and terminates the bending deformation of the tensile deformation mechanism 20A at the predicted bending deformation end timing. This further improves the accuracy of the return control after the sheet 2 stops moving.

[0067] Furthermore, it is preferable that the tensile deformation mechanism 20A is configured to allow adjustment of the amount of bending deformation. Specifically, it is preferable that the tensile deformation mechanism 10A adjusts the amount of bending deformation by changing the eccentric cam 21 to a different size (eccentric cam 21X, 21Y). In addition, it is preferable that the control device 40 (adjustment unit 43) controls the rotation angle of the eccentric cam 21 of the tensile deformation mechanism 20A in order to adjust the amount of bending deformation. This makes it possible to set an appropriate amount of deformation according to various production conditions.

[0068] The sensor 30 preferably includes a position sensor 31 for detecting the position of the sheet 2 in the transport path 9. Furthermore, the sensor 30 preferably includes a speed sensor 32 for detecting the transport speed of the sheet 2 in the transport path 9. This allows the position and transport speed of the sheet 2 to be used as transport information.

[0069] [3. Modified Versions] Figures 6(A) and 6(B) show a first modified version of the deformation device 20. The tensile deformation mechanism 20B in this first modified version is the same as the tensile deformation mechanism 20A, except for the shape of the cam 21B and the fact that the member used as a driven member is an elastic ring 22B. The tensile deformation mechanism 20B shown in Figures 6(A) and 6(B) has a cam 21B whose cam surface is elliptical when viewed from the rotation axis 21A, and an elastically deformable elastic ring 22B is attached to the outer circumference of this cam 21B. The elastic ring 22B is attached to the cam 21B in a deformable manner. A part of the outer circumference of the elastic ring 22B on the upstream side is bonded to the back surface 11A of the buffer plate 10, and a part of the outer circumference of the elastic ring 22B on the downstream side is bonded to the mounting base 15. Therefore, even if the cam 21B rotates, the elastic ring 22B does not rotate.

[0070] Figure 6(A) shows the tensile deformation mechanism 20B in a non-bending deformation state, and Figure 6(B) shows the tensile deformation mechanism 20B in a bending deformation state. In the non-bending deformation state shown in Figure 6(A), the cam 21B is positioned so that the longest radius of the cam surface is aligned with the transport direction MD (i.e., the amount of protrusion of the cam surface of the cam 21B toward the buffer plate 10 is maximized). In the bending deformation state shown in Figure 6(B), the cam 21B is rotated 90° from the non-bending deformation state, and the shortest radius of the cam surface of the cam 21B is positioned so that it is aligned with the transport direction MD (i.e., the amount of protrusion of the cam surface of the cam 21B toward the buffer plate 10 is minimized).

[0071] As shown in Figures 6(A) and (B), when the cam 21B is rotated 90° in a predetermined rotational direction, the shape of the elastic ring 22B deforms to match the shape of the cam 21B, changing from an ellipse elongated in the transport direction MD as shown in Figure 6(A) to an ellipse elongated in the vertical direction as shown in Figure 6(B). Due to the deformation of the elastic ring 22B, the portion of the back surface 11A connected to the elastic ring 22B is displaced downstream, so the buffer plate 10 is deformed into a curved surface in which a part of the surface 11 is convex toward the downstream side.

[0072] To return from the bent deformation state shown in Figure 6(B) to the non-bent deformation state shown in Figure 6(A), the cam 21B is rotated 90° in a predetermined rotational direction, or rotated 90° in the opposite direction to the predetermined rotational direction (forward rotation) (reverse rotation). In this case, the control by the control device 40 is the same as the control of the operation of the tensile deformation mechanism 20A described above, except that the range of the rotation angle of the cam 21B for each cycle of operation of the tensile deformation mechanism 20B is 180°. The same effect as the tensile deformation mechanism 20A described above can be obtained with this tensile deformation mechanism 20B as well. Furthermore, in the case of a tensile deformation mechanism 20B having an elliptical cam 21B, the amount of deformation of the bending deformation can be adjusted by the control device 40 performing control to change the angle range (phase) of the cam 21B used for bending deformation (control of the adjustment unit 43 in Figure 1).

[0073] Figures 7(A) and 7(B) show a second modification of the deformation device 20. The deformation device 20 according to the second modification is configured as a buckling deformation mechanism 20C. The buckling deformation mechanism 20C includes a movable element 22C connected to the upper end of the buffer plate 10 and movable in the vertical direction, and a driver element 21C that moves the movable element 22C in the vertical direction. The downward movement of the movable element 22C presses the buffer plate 10 downward and applies bending deformation. In this case, the movable element 22C is the driven element of the buckling deformation mechanism 20C (deformation device 20), and the driver element 21C is the driving element.

[0074] As shown in Figures 7(A) and 7(B), the upper end of the buffer plate 10 is supported by a movable element 22C. This movable element 22C is an element corresponding to the upper support member 12U in the tensile deformation mechanism 20A shown in Figure 1, and differs from the upper support member 12U in that it is provided so as to be movable in the vertical direction relative to the frame 13. A driver element 21C is provided in contact with the upper end of the movable element 22C. The driver element 21C is composed of, for example, a cam (eccentric cam), and the rotation of the driver element 21C causes the movable element 22C to move in the vertical direction. When the driver element 21C rotates in a predetermined rotational direction, the movable element 22C is pushed down from the upper position shown in Figure 7(A) to the lower position shown in Figure 7(B), and the movable element 22C presses the buffer plate 10 from above to below, causing buckling deformation (bending deformation) to the buffer plate 10. As a result, the buffer plate 10 is deformed into a curved shape in which a part of the surface portion 11 is convex toward the downstream side, resulting in the bent deformation state shown in Figure 7(B).

[0075] When the downward pressure on the movable element 22C is released by the rotation of the driver element 21C in a predetermined rotational direction, the movable element 22C returns from the lower position shown in Figure 7(B) to the upper position shown in Figure 7(A). As a result, the pressure on the buffer plate 10 is released, and the buffer plate 10 returns to the non-bending deformation state shown in Figure 7(A) due to its own elastic force. In this case, since the driver element 21C is rotated 360° with each cycle of operation of the buckling deformation mechanism 20C, the control by the control device 40 is the same as the control of the operation of the tensile deformation mechanism 20A described above. The same effect as the tensile deformation mechanism 20A described above can be obtained with this buckling deformation mechanism 20C as well. Furthermore, the amount of bending deformation can be adjusted by adjusting the amount of vertical movement of the movable element 22C. The amount of vertical movement of the movable element 22C can be changed by replacing the driver element 21C with one that has a different deformation amount set, or by adjusting the rotation angle of the driver element 21C using the adjustment unit 43 (see Figure 1), as explained with reference to Figures 5(A) to (D) above.

[0076] Figures 8(A) and 8(B) show a third modified example of the deformation device 20. In this third modified example, the orientation of the buffer plate 10' differs from that of the buffer plate 10 (and consequently, the arrangement of the upper support member 12U is also different), and the deformation device 20 consists of a tensile deformation mechanism 20D. The arrangement of the cam 21 (eccentric cam) D and the driven member 22D of the tensile deformation mechanism 20D differs from that of the tensile deformation mechanism 20A, but other aspects are the same as those of the tensile deformation mechanism 20A. First, the orientation of the buffer plate 10' will be described. As shown in Figures 8(A) and 8(B), the lower part 10L of the buffer plate 10' is provided substantially vertically along the vertical direction, and the upper part 10U above the lower part 10L is formed in a shape that inclins upstream as it goes upward. In the buffer plate 10', a surface portion 11 is set on the upper part 10U.

[0077] The tensile deformation mechanism 20D applies bending deformation by pulling the buffer plate 10' downstream from the back surface 11A opposite to the surface portion 11 set on the upper part 10U. In this tensile deformation mechanism 20D, the cam 21D and the driven member 22D are configured similarly to the eccentric cam 21 and driven member 22 of the tensile deformation mechanism 20A, except for their arrangement. Specifically, while the eccentric cam 21 and driven member 22 of the tensile deformation mechanism 20A were located on the back surface of the contact point 11P, the cam 21D and driven member 22D of the tensile deformation mechanism 20D are located on the back surface 11A of the upper part 10U. Figure 8(A) shows the tensile deformation mechanism 20D in a non-bending deformation state. When the cam 21D rotates from this non-bending deformation state, the driven member 22D is displaced downstream. As a result, as shown in Figure 8(B), a portion of the upper part 10U, including the contact point 11P where the front part 2F of the sheet 2 makes contact, is deformed into a curved shape that is convex toward the downstream side, resulting in a bent deformation state.

[0078] When the cam 21D is rotated from the bent deformation state shown in Figure 8(B), it returns to the non-bent deformation state shown in Figure 8(A). The same effect as the tensile deformation mechanism 20A described above can be obtained with this tensile deformation mechanism 20D. Furthermore, since the lower part 10L of the buffer plate 10' is provided almost vertically, when the sheet 2 that has collided with the upper part 10U falls downward, the front part 2F of the sheet 2 is less likely to interfere with the lower part 10L of the buffer plate 10'. Therefore, when the sheet 2 falls into the hopper 8A, disturbances in the posture of the sheet 2 can be suppressed.

[0079] Figures 9(A) and 9(B) show a fourth modified example of the deformation device 20. The tensile deformation mechanism 20E in this fourth modified example is configured in the same way as the tensile deformation mechanism 20A, except that it has a pump 21E as a driving element and an elastic tube 22E as a driven element. The elastic tube 22E is a bag-like body with an internal space into which air is injected, and in the non-bending deformation state shown in Figure 9(A), it is provided in an expanded state due to the air pressure injected into the internal space. A portion of the outer circumference of the elastic tube 22E on the upstream side is bonded to the back surface 11A of the buffer plate 10, and a portion of the outer circumference of the elastic tube 22E on the downstream side is bonded to the mounting base 15.

[0080] A pump 21E capable of sucking and injecting air is connected to the elastic tube 22E. By driving the pump 21E, air is sucked from the elastic tube 22E, causing the elastic tube 22E to contract. Consequently, a portion of the surface portion 11, including the contact point 11P where the front portion 2F of the sheet 2 makes contact, deforms into a curved surface that is convex toward the downstream side, and the buffer plate 10 deforms from the non-bent deformation state shown in Figure 9(A) to the bent deformation state shown in Figure 9(B). Furthermore, in the bent deformation state shown in Figure 9(B), when air is injected into the elastic tube 22E by the pump 21E to inflate the elastic tube 22E, the buffer plate 10 returns from the bent deformation state shown in Figure 9(B) to the non-bent deformation state shown in Figure 9(A). In this case, the control by the control device 40 is the same as the control of the operation of the tensile deformation mechanism 20A described above, except that the pump 21E is instructed to suck and inject air for each cycle of operation of the tensile deformation mechanism 20E. The same effects as those of the tensile deformation mechanism 20A described above can be obtained with this tensile deformation mechanism 20E. In addition, in the case of the tensile deformation mechanism 20E, the amount of bending deformation is adjusted by adjusting the air intake and injection amount of the adjustment unit 43 (see Figure 1) of the control device 40.

[0081] Figures 10(A) and 10(B) show a fifth modified example of the deformation device 20. This fifth modified example is a modification of the third modified example described above. Specifically, it is the same as the third modified example except that the deformation device 20 is composed of a pressing deformation mechanism 20F. This pressing deformation mechanism 20F applies bending deformation by pressing down the upper part 10U of the buffer plate 10' from the back surface 11A on the opposite side of the surface portion 11 set on the upper part 10U.

[0082] The pressing deformation mechanism 20F includes an upper support member 12UX and a cam 21F. The upper support member 12UX has a lower surface portion 120 fixed to the upper part 10U of the buffer plate 10' and an upper surface portion 121 to which the cam 21F is attached. The cam 21F is positioned above the upper surface portion 121. Specifically, in the non-bending deformation state shown in Figure 10(A), the upper part 10U of the buffer plate 10' is provided in a curved shape toward the upstream side, and the lower surface portion 120 of the upper support member 12UX is fixed to the top of the back surface 11A side of the buffer plate 10'. The pressing deformation mechanism 20F is configured to push the upper support member 12UX downward (or return it upward) by the rotation of the cam 21F which is positioned in contact with the upper surface portion 121.

[0083] When the cam 21F rotates in a predetermined direction from the non-bent deformation state shown in Figure 10(A), the upper support member 12UX is displaced downward. Since the upper part 10U of the buffer plate 10' is fixed to the lower surface portion 120 of the upper support member 12UX, when the upper support member 12UX is displaced downward, the buffer plate 10' is deformed into a bent state, as shown in Figure 10(B), in which a portion of the upper part 10U, including the contact point 11P where the front portion 2F of the sheet 2 makes contact, is curved and convex toward the downstream side. When the cam 21F is rotated from the bent deformation state shown in Figure 10(B), the buffer plate 10' returns to the non-bent deformation state shown in Figure 10(A). The same effect as the tensile deformation mechanism 20A described above can be obtained with this pressing deformation mechanism 20F. Furthermore, the same effect as the tensile deformation mechanism 20D according to the third modified example can also be obtained.

[0084] Figures 11(A) and (B) show a sixth modification of the deformation device 20. In this sixth modification, the deformation device 20 is composed of a tensile deformation mechanism 20G. This tensile deformation mechanism 20G is the same as the tensile deformation mechanism 20A, except that it includes a link mechanism 22G as a driven element. As shown in Figures 11(A) and (B), the link mechanism 22G includes a mounting portion 130 attached to the back surface 11A side of the buffer plate 10 (more specifically, the back surface side of the contact point 11P), and a lever 131 connecting the mounting portion 130 and the rotating body 21G. The lever 131 is connected to the rotating body 21G at a connection point 132 that is shifted radially outward with respect to the center point O of the rotating body 21G. The tensile deformation mechanism 20G is configured such that the rotation of the rotating body 21G activates the link mechanism 22G to pull the buffer plate 10 downstream (or return it upstream).

[0085] When the rotating body 21G is rotated in a predetermined direction from the non-bent deformation state shown in Figure 11(A), the buffer plate 10 is pulled downstream by the link mechanism 22G. As a result, the buffer plate 10 is deformed into a bent deformation state in which a portion of the area including the contact point 11P where the front part 2F of the sheet 2 makes contact becomes curved and convex toward the downstream side, as shown in Figure 11(B). When the rotating body 21G is rotated in a predetermined direction from the bent deformation state shown in Figure 11(B), the buffer plate 10 returns to the non-bent deformation state shown in Figure 11(A). The same effect as the tensile deformation mechanism 20A described above can be obtained with this tensile deformation mechanism 20G as well.

[0086] Figures 12(A) and (B) show modified examples of the link mechanism used in the tensile deformation mechanism 20G. Figures 12(A) and (B) show an example configuration of the link mechanism 22H having three levers 140 to 142. Of the three levers 140 to 142 in the link mechanism 22H, the first lever 140 is attached at one end to the back surface 11A side of the buffer plate 10 (more specifically, the back surface side of the contact point 11P) via a mounting portion 130, and is connected at the other end to the second lever 141 and the third lever 142. The second lever 141 is attached at its downstream end to a member on the counter ejector 8 side (for example, a mounting base 15) via a base portion 143. The third lever 142 extends downward from one end (upper end) connected to the first lever 140, and is connected at the other end (lower end) to the rotating body 21H. The third lever 142 is connected to the rotating body 21H at a connection point 144 that is shifted radially outward with respect to the center point O of the rotating body 21H.

[0087] When the rotating body 21H is rotated in a predetermined direction from the non-bent deformation state shown in Figure 12(A), the buffer plate 10 is pulled downstream by the link mechanism 22H. Specifically, the link mechanism 22H works by the third lever 142 moving downward, which causes the first lever 140 to move downstream and pull the buffer plate 10 downstream. As a result, the buffer plate 10 is bent, with a portion of the area including the contact point 11P where the front part 2F of the sheet 2 makes contact becoming curved and convex toward the downstream side, as shown in Figure 12(B). When the rotating body 21H is rotated in a predetermined direction from the bent deformation state shown in Figure 12(B), the buffer plate 10 returns to the non-bent deformation state shown in Figure 12(A).

[0088] Figures 13(A) and (B) show another modified example of the link mechanism used in the tensile deformation mechanism 20G. The link mechanism 22I in Figures 13(A) and (B) includes a U-shaped driven member 150 attached to an eccentric cam 21I and a lever 151 for connecting the driven member 150 to the back surface 11A side of the buffer plate 10. The lever 151 is attached at one end to the back surface 11A side of the buffer plate 10 (more specifically to the back surface of the contact point 11P) via a first mounting portion 152, and at the other end to the driven member 150 via a second mounting portion 153. The lever 151 is provided in a position where one end is positioned upward and the other end is positioned downward, and is rotatable about an axis 154 provided between the one end and the lower end. When the eccentric cam 21I rotates about the rotation axis 155, the driven member 150 moves upstream or downstream, activating the link mechanism 22I.

[0089] When the eccentric cam 21I is rotated in a predetermined direction from the non-bent deformation state shown in Figure 13(A), the buffer plate 10 is pulled downstream by the link mechanism 22I. Specifically, in the link mechanism 22I, the driven member 150 moves upstream, causing the lever 151 to rotate counterclockwise around the axis 154 in the figure, pulling the buffer plate 10 downstream. As a result, the buffer plate 10 is bent, with a portion of the area including the contact point 11P where the front part 2F of the sheet 2 makes contact becoming curved and convex toward the downstream side, as shown in Figure 13(B). When the eccentric cam 21I is rotated in a predetermined direction from the bent deformation state shown in Figure 13(B), the buffer plate 10 returns to the non-bent deformation state shown in Figure 13(A).

[0090] [4. Others] The specific examples of the driving element and driven element in the above-described embodiment of the deformation device 20 and each of its modifications are illustrative and not limited thereto. For example, in the embodiment and each of its modifications, a linearly moving solenoid actuator may be used as a driving element instead of a cam. Also, although a speed sensor 32 was given as an example of one of the sensors 30, instead of the transport speed detected by the speed sensor 32, a transport speed calculated based on the machine production speed obtained from a production management device (not shown) may be used as one of the transport information.

[0091] Furthermore, in the embodiments and modifications described above, the operation of the deformation device 20 is controlled to apply bending deformation to the cushioning plate 10 based on the transport information detected by the sensor 30, but this is not limited to this. For example, the control device 40 may use the timing at which the box-making sheet material 2A is supplied from the paper feeding unit 3 and the machine speed of the box-making machine 1 as transport information to control the operation of the deformation device 20 to apply bending deformation to the cushioning plate 10. In this case, the control device 40 can fix the distance from the paper feeding unit 3 to the cushioning plate 10 and consider the machine speed of the box-making machine 1 as the transport speed of the box-making sheet material 2A to calculate the timing at which the box-making sheet material 2A is processed into a sheet 2 and comes into contact with the cushioning plate 10. Based on the timing thus calculated, the control device 40 may control the operation of the deformation device 20 to apply bending deformation to the cushioning plate 10.

[0092] [5. Addendum] The following addendum is disclosed with respect to the above embodiments.

[0093] [Note 1] A counter-ejector provided at the downstream end of a box-making machine, which stacks and counts corrugated cardboard sheets sent from the transport path of the box-making machine in a predetermined transport direction into a hopper and discharges them in batches, comprising: a buffer plate formed of a deformable elastic plate-shaped member, erected on the downstream side in the transport direction relative to the hopper, and having a surface portion that contacts the front portion of the corrugated cardboard sheets sent from the transport path; a deformation device that applies a bending deformation to the buffer plate such that the surface portion becomes convex toward the downstream side; a sensor positioned upstream of the buffer plate in the transport direction, which detects transport information relating to the corrugated cardboard sheets being transported along the transport path; and a control device that controls the operation of the deformation device to apply the bending deformation to the buffer plate based on the transport information detected by the sensor. [Note 2] The counter-ejector according to Note 1, wherein the deformation device includes a tensile deformation mechanism that pulls the buffer plate toward the downstream side from the back surface opposite to the surface portion to apply the bending deformation. [Note 3] The counter ejector according to Note 2, characterized in that the tensile deformation mechanism includes a cam that rotates about a rotation axis along the machine width direction of the box-making machine, and a driven member connected to the back surface of the buffer plate, which applies the bending deformation to the buffer plate in accordance with the rotation of the cam. [Note 4] The counter ejector according to Note 1, characterized in that the buffer plate has a lower part that is provided substantially vertically along the vertical direction, and the upper part above the lower part is formed in a shape that is inclined towards the upstream side in the conveying direction as it goes upward, and the surface portion is set on the upper part, and the deformation device is arranged to apply the bending deformation to the surface portion set on the upper part of the buffer plate. [Note 5] The counter ejector according to Note 4, characterized in that the deformation device includes a tensile deformation mechanism that applies the bending deformation to the buffer plate by pulling it downstream from the back surface opposite to the surface portion set on the upper part. [Note 6] The counter ejector according to Note 4, characterized in that the deformation device includes a pressing deformation mechanism that applies the bending deformation by pressing down the upper part of the buffer plate from the back surface opposite to the surface portion set on the upper part.[Note 7] The counter ejector according to Note 1, wherein the deformation device includes a movable element connected to the upper end of the buffer plate and movable in the vertical direction, and a drive element that drives the movable element in the vertical direction, and includes a buckling deformation mechanism that presses the buffer plate downward by the downward movement of the movable element to apply the bending deformation. [Note 8] The counter ejector according to any one of Notes 1 to 7, wherein the control device controls the operation of the deformation device each time the corrugated cardboard sheet is fed out from the transport path. [Note 9] The counter ejector according to any one of Notes 1 to 8, wherein the control device predicts the timing at which the front part of the corrugated cardboard sheet collides with the buffer plate based on the transport information, sets a bending deformation start timing based on the timing of collision with the buffer plate, and controls the operation of the deformation device to apply the bending deformation to the buffer plate at the bending deformation start timing. [Note 10] The counter ejector according to any one of Notes 1 to 9, characterized in that the control device controls the bending deformation speed at which the surface portion is displaced downstream based on the transport information. [Note 11] The counter ejector according to Note 9 or 10, characterized in that the control device controls the bending deformation start timing so that the bending deformation by the deformation device starts immediately before the front portion of the corrugated cardboard sheet collides with the buffer plate, based on the transport information. [Note 12] The counter ejector according to Note 9 or 10, characterized in that the control device controls the bending deformation start timing so that the bending deformation by the deformation device starts when the front portion of the corrugated cardboard sheet collides with the buffer plate, based on the transport information. [Note 13] The counter ejector according to any one of Notes 10 to 12, characterized in that the control device controls the bending deformation speed to a speed slower than the movement speed of the front portion of the corrugated cardboard sheet immediately before it collides with the buffer plate.[Note 14] The counter-ejector according to any one of Notes 10 to 13, characterized in that the control device controls the bending deformation speed so that the front part of the corrugated sheet contacts the surface of the cushioning plate from immediately after the corrugated sheet collides with the cushioning plate until it stops moving in the transport direction. [Note 15] The counter-ejector according to any one of Notes 1 to 14, characterized in that the control device predicts the timing at which the front part of the corrugated sheet that has collided with the cushioning plate stops moving in the transport direction as the bending deformation end timing based on the transport information, and terminates the bending deformation of the deformation device at the predicted bending deformation end timing. [Note 16] The counter-ejector according to any one of Notes 1 to 15, characterized in that the control device controls the return speed until the cushioning plate returns from the bent deformation state to the non-bent deformation state where bending deformation has not been applied by the deformation device. [Note 17] The counter ejector according to any one of Notes 1 to 16, characterized in that the deformation device is configured to adjust the amount of deformation of the bending deformation. [Note 18] The counter ejector according to any one of Notes 3 and Notes 8 to 17 referencing Note 3, characterized in that the control device controls the rotation angle of the cam of the tensile deformation mechanism in order to adjust the amount of deformation of the bending deformation. [Note 19] The counter ejector according to any one of Notes 7 and Notes 8 to 18 referencing Note 7, characterized in that the control device controls the amount of vertical movement of the mover of the buckling deformation mechanism in order to adjust the amount of deformation of the bending deformation. [Note 20] The counter ejector according to any one of Notes 1 to 19, characterized in that the sensor includes a position sensor for detecting the position of the corrugated cardboard sheet in the transport path. [Note 21] The counter ejector according to any one of Notes 1 to 20, characterized in that the sensor includes a speed sensor for detecting the transport speed of the corrugated cardboard sheet in the transport path. [Note 22] A box-making machine characterized by being equipped with the counter ejector according to any one of Notes 1 to 21.

[0094] 1 Box making machine 2,2' Sheet (corrugated cardboard sheet) 2A Sheet material for box making 2B Batch 2F Front 3 Paper feeding section 4 Printing section 5 Paper discharge section 6 Die cutting 7 Folder gluer 8 Counter ejector 8A Hopper 9 Conveyor path 9A Outlet 10,10' Buffer plate 10L Lower part 10U Upper part 11 Front part 11A Back side 11P Contact point 12L Lower support member 12U Upper support member 13 Frame 14 Plate 15 Mounting base 20 Deformation device 20A Tension deformation mechanism 20B Tension deformation mechanism 20C Buckling deformation mechanism 20D Tension deformation mechanism 20E Tension deformation mechanism 21 Eccentric cam (cam) 21A Rotating shaft 21B,21C,21D Cam 21C 21E Drive element Pump 21X First cam 21Y Second cam 22 Driven member 22B Elastic ring 22C Moving element 22D Driven member 22E Elastic tube 23 Inner wall surface 24 Vertical surface 30 Sensor 31 Position sensor 32 Speed ​​sensor 40 Control device 41 Timing prediction unit 42 Operation control unit 43 Adjustment unit MD Conveying direction O Center point X Deformation amount XA Deformation amount XB Deformation amount Y Deformation amount

Claims

1. A counter-ejector provided at the downstream end of a box-making machine for stacking, counting, and discharging corrugated cardboard sheets sent from the transport path of the box-making machine in a predetermined transport direction into a hopper, comprising: a buffer plate formed of a deformable, elastic plate-shaped member, erected on the downstream side in the transport direction relative to the hopper, and having a surface portion that contacts the front portion of the corrugated cardboard sheets sent from the transport path; a deformation device that applies a bending deformation to the buffer plate such that the surface portion becomes convex toward the downstream side; a sensor positioned upstream of the buffer plate in the transport direction, which detects transport information relating to the corrugated cardboard sheets being transported along the transport path; and a control device that controls the operation of the deformation device to apply the bending deformation to the buffer plate based on the transport information detected by the sensor.

2. The counter-ejector according to claim 1, characterized in that the deformation device includes a tensile deformation mechanism that pulls the buffer plate downstream from the back surface opposite to the surface portion to apply the bending deformation.

3. The counter ejector according to claim 2, characterized in that the tensile deformation mechanism includes a cam that rotates about a rotation axis along the machine width direction of the box-making machine, and a driven member connected to the back surface of the buffer plate, which applies the bending deformation to the buffer plate in accordance with the rotation of the cam.

4. The counter ejector according to claim 1, characterized in that the buffer plate has a lower part that is provided substantially vertically along the vertical direction, and the upper part above the lower part is formed in a shape that is inclined toward the upstream side in the conveying direction as it goes upward, the surface portion is set on the upper part, and the deformation device is arranged to apply the bending deformation to the surface portion set on the upper part of the buffer plate.

5. The counter ejector according to claim 4, characterized in that the deformation device includes a tensile deformation mechanism that pulls the buffer plate downstream from the back surface opposite to the surface portion set on the upper part to apply the bending deformation.

6. The counter ejector according to claim 4, characterized in that the deformation device includes a pressing deformation mechanism that applies the bending deformation by pressing down the upper part of the buffer plate from the back surface opposite to the surface portion set on the upper part.

7. The counter ejector according to claim 1, wherein the deformation device includes a movable element connected to the upper end of the buffer plate and movable in the vertical direction, and a drive element for driving the movable element in the vertical direction, and the deformation device includes a buckling deformation mechanism that presses the buffer plate downward by the downward movement of the movable element to impart the bending deformation.

8. The counter ejector according to claim 1, characterized in that the control device controls the operation of the deformation device each time the corrugated cardboard sheet is fed out from the transport path.

9. The counter ejector according to claim 1, characterized in that the control device predicts the timing at which the front portion of the corrugated cardboard sheet collides with the buffer plate based on the transport information, sets a bending deformation start timing based on the timing of the collision with the buffer plate, and controls the operation of the deformation device to apply the bending deformation to the buffer plate at the bending deformation start timing.

10. The counter ejector according to claim 1, characterized in that the control device controls the bending deformation rate at which the surface portion is displaced downstream, based on the transport information.

11. The counter ejector according to claim 9, characterized in that the control device controls the timing of the start of the bending deformation by the deformation device based on the transport information, so as to start the bending deformation by the deformation device immediately before the front portion of the corrugated cardboard sheet collides with the buffer plate.

12. The counter ejector according to claim 9, characterized in that the control device controls the timing of the start of the bending deformation so that when the front part of the corrugated cardboard sheet collides with the buffer plate, the bending deformation by the deformation device is started based on the transport information.

13. The counter ejector according to claim 10, characterized in that the control device controls the bending deformation speed to a speed slower than the speed at which the front part of the corrugated cardboard sheet moves immediately before it collides with the buffer plate.

14. The counter ejector according to claim 10, characterized in that the control device controls the bending deformation speed so that the front portion of the corrugated sheet contacts the surface portion of the cushioning plate from immediately after the corrugated sheet collides with the cushioning plate until the movement in the transport direction stops.

15. The counter ejector according to claim 1, characterized in that the control device predicts the timing at which the front portion of the corrugated cardboard sheet that has collided with the buffer plate stops moving in the transport direction, based on the transport information, as the bending deformation termination timing, and terminates the bending deformation of the deformation device at the predicted bending deformation termination timing.

16. The counter ejector according to claim 1, characterized in that the control device controls the recovery speed from the bent deformation state in which the buffer plate is subjected to the bending deformation to the non-bent deformation state in which the bending deformation is not subjected.

17. The counter-ejector according to claim 1, characterized in that the deformation device is configured to adjust the amount of deformation of the bending deformation.

18. The counter ejector according to claim 3, characterized in that the control device controls the rotation angle of the cam of the tensile deformation mechanism in order to adjust the amount of bending deformation.

19. The counter-ejector according to claim 7, characterized in that the control device controls the amount of vertical movement of the movable element of the buckling deformation mechanism in order to adjust the amount of deformation of the bending deformation.

20. The counter ejector according to claim 1, characterized in that the sensor includes a position sensor for detecting the position of the corrugated cardboard sheet in the transport path.

21. The counter ejector according to claim 1, characterized in that the sensor includes a speed sensor for detecting the transport speed of the corrugated cardboard sheet in the transport path.

22. A box-making machine characterized by comprising a counter-ejector as described in any one of claims 1 to 21.

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