Blank joining module with rough positioning control

Abstract

The present invention relates to a blank joining module of a converter. The blank joining module includes an upper feed device configured to supply and convey an upper blank (2b) and a lower blank (2a) toward a joining point (J) where the upper blank is superposed on the lower blank. The blank joining module includes a detection system and an alignment control system including a position correction device (86) configured to displace the upper blank to align it with the lower blank.

Description

Technical Field

[0001] The present invention relates to a converting machine for manufacturing paper and cardboard containers such as folding boxes. Specifically, it relates to a blank joining module configured to join two blanks before integrally folding the blanks.

Background Art

[0002] Converting machines such as folder-gluers are used in the manufacture of packaging products such as cardboard boxes and corrugated boxes. These machines include a plurality of workstations that can fold, glue, count, stack, and batch-adjust the boxes to form the boxes.

[0003] Folder-gluers can be configured to manufacture many different types of packaging containers and folding boxes. One type of assembled box that joins two blanks is sometimes called a "shelf-ready" box. A shelf-ready box includes an outer box and an inner box glued together. The inner box functions as a container for the goods to be stored, and the outer box can function as protection during transportation. This type of box is commonly used in supermarkets and stores, and the inner box is placed on the shelf with the goods inside.

[0004] When manufacturing a box by joining a plurality of blanks, a blank joining module with a double feeder is required. Specifically, each of the first blank and the second blank requires a dedicated feeder.

[0005] An example of a blank joining module is described in European Patent Application Publication No. 2072241. Since the assembled box is an assembly of two different blanks, it is necessary to ensure that the blanks are correctly aligned before joining the blanks.

[0006] To control alignment, the blank joining module of European Patent Application Publication No. 2072241 includes upper and lower crete belts with abutting portions for controlling the positions of both the first and second blanks.

[0007] U.S. Patent Application Publication No. 2002 / 077236 discloses an alignment device configured to align an insert sheet and a blank with each other. The insert sheet is conveyed along separate conveying paths until the insert sheet and the blank are joined.

[0008] Alignment is achieved by detecting the positions of each blank and the insert sheet. Next, displacement is applied to the insert sheet to advance or delay its arrival, and the insert sheet is adapted to be aligned with the blank. This displacement is provided by a conveyor belt, which is configured to accelerate or decelerate each insert sheet according to whether each insert sheet arrives at the sensor earlier or later.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0010] In view of the prior art, an object of the present invention is to provide an aiming control system configured to perform accurate aiming correction while maintaining a high production speed.

Means for Solving the Problems

[0011] This object is solved by the blank joining module according to claim 1.

[0012] According to a first aspect of the present invention, there is provided a blank joining module comprising an upper feeder device configured to supply an upper blank, a lower feeder device configured to supply a lower blank, an upper conveyor system configured to convey the upper blank from the upper feeder device, and a lower conveyor system configured to convey the lower blank from the lower feeder device, wherein the upper conveyor system and the lower conveyor system are configured to convey the upper blank and the lower blank toward a joining point where the upper blank is positioned on the lower blank.

[0013] The blank joining module comprises a centering control configuration including a detection system and a position correction device. The detection system comprises an upper transfer sensor configured to detect the passage of the upper blank and a lower transfer sensor configured to detect the passage of the lower blank.

[0014] The centering control configuration further comprises a control unit and a memory. The control unit is configured to receive detection signals from the upper transfer sensor and the lower transfer sensor and calculate the total relative displacement between the upper blank and the lower blank. The control unit is further configured to operate the position correction device to displace the upper blank so as to align with the lower blank and impart a correction displacement in the conveying direction to the upper blank.

[0015] The present invention is based on the recognition that it is possible to maintain the production speed defined by the lower blank by only correcting the position of the upper blank. In a preferred embodiment, only the position of the upper blank is corrected. As a result, the position of the lower blank is not corrected.

[0016] The total relative displacement is the displacement of the upper blank with respect to the actual position of the lower blank and is the displacement with respect to the preset assembly positions of the upper and lower blanks in the conveying direction. The total relative displacement is determined by the detection times at the leading edges of the upper and lower blanks in each transfer sensor.

[0017] Therefore, the actual position of the lower blank can be taken as the reference position of the upper blank, and the position correction device is configured to apply a correction displacement so that the upper blank is aligned with the lower blank at the joint point.

[0018] The conveying direction can be defined as the horizontal direction extending from the upper and lower feeder devices to the joint point. The conveying direction preferably coincides with the longitudinal direction of the converter. The conveying direction extends between the inlet and outlet of the converter. Therefore, the conveying direction can extend widely from the upper and lower feeder devices to the folding and gluing modules of the converter and further downstream to the delivery module of the converter.

[0019] Upstream of the branch point, the conveying path of the upper blank is inclined downward. For the lower blank, the conveying path upstream of the branch point can be horizontal or have a deviation of about 15°.

[0020] The term "upstream side in the conveying direction" means the direction from the branch point J towards the upper feeder device. The term "downstream side in the conveying direction" means the direction from the upper feeder device towards the branch point J.

[0021] The correction displacement corresponds to the total relative displacement. The displacement is given by the acceleration or deceleration of the upper blank.

[0022] The memory preferably includes instructions for performing calculations and a temporary memory for storing the total relative displacements of each blank existing between the feeder unit and the joint point.

[0023] The upper conveyor system can include an alignment conveyor and a locating conveyor.

[0024] Preferably, the upper blanks are carried at a selected displacement distance such that each upper blank is displaced relative to a preset target position of the upper blank.

[0025] In a preferred embodiment, the selected displacement distance is selected such that each upper blank always arrives at the position of the upper transfer sensor with the total relative displacement relative to the lower blank, and the position of each upper blank is corrected by a position correction device.

[0026] In one embodiment, the selected displacement distance is selected such that each upper blank requires correction in the same direction in the upper conveyance path. The same direction means that each upper blank is corrected so as to be displaced relative to the upstream or downstream direction in the upper conveyance path and relative to the conveyance direction.

[0027] In one embodiment, the lower transfer sensor is configured to detect the actual position of the lower blank before the upper transfer sensor detects the actual position of the upper blank.

[0028] Thereby, the control unit can first determine a reference position from the position of the lower blank.

[0029] Preferably, only the position of the upper blank is corrected.

[0030] In one embodiment, the lower transfer sensor is configured to detect the actual position of the lower blank before the upper transfer sensor detects the actual position of the upper blank.

[0031] In one embodiment, the position correction device includes a housing shroud having an extension extending further upstream in the conveyance direction than the cleat belt, and the upper transfer sensor is disposed on the protruding extension.

[0032] In one embodiment, the actual speed of the upper blank is different from the actual speed of the lower blank.

[0033] In another embodiment, the release timing of the upper blank or the actual conveyance speed of the upper blank is selected so as to impart a selected displacement to the upper blank relative to the estimated position of the upper blank.

[0034] In one embodiment, the position correction device includes a crete belt having at least one abutting portion, and the control unit is configured to position the abutting portion to abut against the front edge or the rear edge of the upper blank, and correct the position of the upper blank in the conveyance direction.

[0035] The memory preferably includes a first set of operation instructions for a first operation mode in which the position correction device is configured to abut against the rear edge of the upper blank so that each upper blank is accelerated by the position correction device, and a second set of operation instructions for a second operation mode in which the position correction device is configured to abut against the front edge of the upper blank so that each blank is decelerated by the position correction device. By acceleration or deceleration, the upper blank can reach its desired position.

[0036] In one embodiment, the position correction device is coupled to a displacement mechanism attached to the structural frame of the blank joining module, and the position correction device is displaceable in the conveyance direction so as to be movable to a first operation position in the first operation mode and to a second operation position in the second operation mode.

[0037] The displacement mechanism includes a motor and a slide mechanism, and the control unit is configured to operate the motor to displace the position correction device according to the longitudinal length of the upper blank and the type of the selected correction mode. The slide mechanism can include a slide rail and a slider.

[0038] In one embodiment, the alignment control configuration further includes an upper feed sensor and a lower feed sensor configured to detect the passage of each of the upper blank and the lower blank, the control unit is configured to determine an initial relative feeder displacement from the difference in detection times, and the control unit is configured to issue a warning signal when the initial relative feeder displacement is greater than a correction threshold value.

[0039] In one embodiment, the upper conveyor system includes an alignment conveyor and an alignment conveyor, the upper alignment conveyor is connected to the alignment conveyor and the upper feeder, the upper feeder is movable in the longitudinal direction, and the upper alignment conveyor has a variable length.

[0040] In one embodiment, the control unit is configured to change the release time and / or the conveying speed of the upper blank based on the length of the upper alignment conveyor.

[0041] Hereinafter, the present invention will be described with reference to the accompanying drawings in which like reference numerals are assigned to like features.

Brief Description of the Drawings

[0042]

Figure 1

Figure 2a

Figure 2b

Figure 3

Figure 4

Figure 5

Figure 6a

Figure 6b

Figure 7

Figure 8a

Figure 8b

Figure 8c

Figure 8d

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0043] Specifically, refer to FIG. 1 showing the converter 1 in the form of the folding-gluing machine 1. The folding-gluing machine 1 is configured to receive the first stack S1 and the second stack S2 of blanks 2, join them, and fold and bond them together to form a folded box 2' or other assembled packaging container.

[0044] There are several types of boxes 2'' and packaging containers and boxes that can be manufactured by the folding-gluing machine 1. One type of such box 2'' is shown in FIGS. 2a and 2b and may be called a "shelf-ready" box 2''. This type of box 2'' is composed of two joined blanks 2b, 2a. One blank 2a may form an inner container and the other blank 2b may form an outer container. In use, the outer container can be manually removed, while the inner container holds the merchandise.

[0045] This type of assembled box 2’’ is initially manufactured by forming a blank 2’ assembled from a first blank 2a and a second blank 2b on a folding-gluing machine 1. Subsequently, the assembled blank 2 undergoes folding and gluing operations.

[0046] As shown in Figure 1, this folding-gluing machine 1 comprises a series of different workstations in the form of modules. The modules can include a blank joining module 10, a folding pre-breaking module 12, a gluing module 14, and a folding module 16 from an inlet A to an outlet B. The folding-gluing machine 1 can further include a main user interface 11 and a quality control system 18. After the gluing module and the folding module, a delivery module and an adjustment section 20 can be provided to count the roof plate-like flow of the folded box 2’’ and separate it into separate batches. The converter 1 further comprises a conveying system 19 including conveyors such as endless belts and rollers configured to convey the first and second blanks 2a, 2b in a conveying direction T. The converter 1 also comprises a control circuit 80 configured to control the operation of the blank joining module 10.

[0047] The blank joining module 10 enables the folding-gluing machine 1 to manufacture the assembled blank 2’. As shown in Figures 3 and 4, the blank joining module 10 comprises a feeder unit 32, an alignment unit 34, a gluing device 100, a positioning control arrangement 36, and a joining transfer machine 38.

[0048] As can be best seen from Figures 3 and 4, the feeder unit 32 comprises a lower feeder device 32a and an upper feeder device 32b. The upper feeder device 32b and the lower feeder device 32a are each configured to supply one blank 2a, 2b at a time in the conveying direction T.

[0049] The upper feeder device 32b is configured to supply a first blank 2b, also referred to as an "upper blank" 2b, from a stack arranged on the upper placement surface 33b. The lower feeder device 32a is configured to supply a second blank 2a, also referred to as a "lower blank" 2a, from a stack arranged on the lower placement surface 33a of the lower feeder device 32a.

[0050] The upper placement surface 33b is located vertically above the lower placement surface 33a. To facilitate access to the upper placement surface 33b, the upper feeder device 32b is displaceable in the longitudinal direction L and the conveying direction T1. In this way, the upper placement surface 33b can be displaced to a position horizontally offset with respect to the lower placement surface 33a. Therefore, the upper placement surface 33b can be moved close to the machine operator.

[0051] As can be best seen from FIGS. 3-5, the upper feeder device 32b is slidably attached to the structural frame 40 of the blank joining module 10. The connection between the upper feeder device 32b and the structural frame 40 can be realized by a slide connection portion. The slide connection portion can include a slide rail 42 and a slider 41. The upper feeder device 32b can be displaced along the slide rail 42 by a motor 44. The motor 44 can perform automatic displacement of the upper placement surface 33b. The control circuit 80 of the blank joining module 10 can automatically operate the motor 44 to displace the upper feeder device 32b to a predetermined operating position calculated from the longitudinal length La of the lower blank 2a in the lower feeder device 32a. The longitudinal length La is the length of the lower blank 2a in the conveying direction T.

[0052] To further facilitate access to the upper feeder device 32b, the blank joining module 10 can further include a modular podium 50. As can be best seen from FIG. 3, the podium 50 includes at least one stepped surface 52a. Preferably, the podium 50 includes a second stepped surface 52b movably disposed on the first stepped surface 52a.

[0053] As shown in FIG. 4, the alignment unit 34 is disposed downstream (in the conveying direction T) of the feeder unit 32 and is configured to laterally align the upper blank 2b and the lower blank 2a to their respective predetermined lateral positions. In this way, when the blanks 2a, 2b are brought into contact with each other at the joining point J, the upper blank 2b and the lower blank 2a are in the correct lateral positions.

[0054] The alignment unit 34 includes an upper alignment device 34b configured to align the upper blank 2b and a lower alignment device 34a configured to align the lower blank 2a. The upper and lower alignment devices 34b, 34a preferably include respective distal upstream coupling ends 35b, 35a fixedly coupled to the upper and lower feeder devices 32b, 32a.

[0055] The lower alignment device 34a is configured to convey the lower blank 2a along a substantially horizontal conveying path Pa. As can be best seen from FIG. 7, the lower alignment device 34a includes an upper pressing member 60a, a lower conveyor 61a, and a guide (not shown). The lower conveyor 61a includes an endless conveyor belt 62a having a contact length Lca configured to contact the lower blank 2a and convey it forward in the conveying direction T.

[0056] As can be best seen from FIGS. 8a - 8d, the upper alignment device 34b includes an upper pressing member 60b and an upper conveyor 61b. The guide 63 is arranged to be straight in the conveying direction T. The upper pressing member 60b and the upper conveyor 61b are arranged at a predetermined angle with respect to the conveying direction T such that the side edge of the lower blank 2a faces the guide 63. The upper conveyor 61b consists of an endless conveyor belt 62b having a contact length Lcb configured to contact the upper blank 2b and send it forward in the conveying direction T.

[0057] Accordingly, the upper alignment device 34b is configured in the same manner as the lower alignment device 34a. However, the upper alignment device 34b has a variable contact length Lcb in the conveying direction T. The upper alignment device 34b further includes a movable distal end 35a coupled to the upper feeder device 32b and a fixed distal end 37b coupled to the structural frame 40 of the blank joining module 10. This enables the upper feeder device 32b to be displaced in the longitudinal direction L while maintaining a fixed connection to the upper alignment device 34b.

[0058] As can be best seen from FIGS. 8b and 8c, the upper conveyor 61b of the upper alignment device 34b further includes a support structure 69 configured to support the conveyor belt 62b. The support structure 69 includes a plurality of rollers 67 (see FIG. 8a) to which the conveyor belt 62b is attached. The rollers 67 are attached to the frame members 70, and a connecting mechanism 68 connects the adjacent frame members 70 to each other. The connecting mechanism 68 is extensible so as to be able to change the distance between the frame members 70. The frame members 70 are displaceable in the conveying direction T. Each roller 67 is attached to the frame member 70 and arranged in a row.

[0059] Preferably, the connecting mechanism 68 includes a plurality of pivotable links 74a, 74b that enable equidistant displacement of the frame member 70. The pivotable connecting links 74a, 74b can be provided by two linear elements. The pivotable connecting links 74a, 74b are coupled to each frame member 70 at a central pivot 75. Also, the pivotable connecting links 74a, 74b are coupled to each other at an upper pivot 76 and a lower pivot 77. The upper pivot 76 and the lower pivot 77 are movable in the longitudinal direction L.

[0060] By coupling the frame member 70 to the central pivot 66, the horizontal position of the central pivot 75 is maintained constant. The support structure has a first distal end 35b coupled to the upper feeder device 32b and a second distal end 37b coupled to the frame 40 of the blank joining module 10.

[0061] The frame member 70 is coupled to the central pivot 75 of the connecting mechanism 68. The frame member 70 includes a first cantilever extension 70a and a second cantilever extension 70b coupled to a frame member bracket 70c.

[0062] The guide roller 67 of the conveyor belt 62b is attached to the first cantilever extension 70a, and the pressing roller 66 is attached to the second cantilever extension 70b. The first and second cantilever extensions 70a, 70b extend horizontally and parallel to each other. The second cantilever extension 70b is disposed vertically above the first cantilever extension 70a.

[0063] The second cantilever extension 70b can be supported by an upper guide rail 71b, and the second cantilever extension 70b can be supported by a lower guide rail 71a. Each of the guide rails 71a, 71b can be in the form of a longitudinal bar disposed below the first and second cantilever extensions 70a, 70b.

[0064] The distal inlet end 35b of the upper alignment device 34b can include a mounting bracket 79 configured to be attached to the upper feeder device 32b. The mounting bracket 79 can further include a fixed structure that forms an inlet section I for the upper pressing roller 66 and the support roller 67 of the conveyor belt 62b. The mounting bracket 79 provides a fixed connection to the cantilever extensions 70b, 70c such that the inlet section I has a constant length regardless of the extension or contraction of the linkage mechanism 68. The distal central pivot 79a is attached to the mounting bracket 79. The second distal central pivot 79b is attached to the frame member 77 of the upper alignment module 34b.

[0065] The guide 63 is not present in this inlet section I defined by the length of the mounting bracket 79. Thus, the upper blank 2b is not guided in the inlet section I. Thereby, the upper blank 2b is transferred out from the upper feeder device 32b before being laterally biased.

[0066] The sizing control arrangement 36 is configured to correct a longitudinal sizing displacement deviation in the transport direction T and align the upper and lower blanks 2b, 2a with each other in the transport direction T. The longitudinal sizing displacement deviation is an unwanted displacement with respect to the preset longitudinal sizing positions Pa_reg, Pb_reg of the blanks 2a, 2b at a certain moment.

[0067] Both the upper and lower blanks 2b, 2a are affected by sizing displacement deviations due to variations in blank transport. Such variations can include variations in the feeder discharge time that result in feeder displacements Δdb_feeder, Δda_feeder in the respective upper and lower feeder devices 32b, 32a. The discharge times of the upper and lower feeder devices 32b, 32a can be earlier or later than the preset discharge time. Another variation is the transport displacement Δdb_transport, Δda_transport of the upper and lower blanks 2b, 2a, which is caused by local wear of the conveyor belt and related support components.

[0068] As shown in FIGS. 4 and 6, the alignment control configuration 36 includes a detection system 83, a position correction device 86, and a control circuit 84. The control circuit includes a control unit 91 and a memory 93.

[0069] As best seen from FIGS. 6a and 6b, the position correction device 86 includes a cleat belt 88 attached to a belt drive mechanism 104. The belt drive mechanism 104 is attached to a frame member 105. The cleat belt 88 is configured to be driven at variable acceleration and speed. The cleat belt 88 includes one or more contact portions 90. Preferably, two contact portions 90 are provided. The position correction device 86 further includes a motor 92 configured to drive the cleat belt 88.

[0070] The position correction device 86 can include an induction sensor 89 configured to detect the position of the cleat belt 88 so as to be able to determine the position of the contact portion 90. The induction sensor 89 can be configured to detect the contact portion 90. The contact portion 90 can include a metallic material that can be detected by the induction sensor 89.

[0071] The position of the upper blank 2b can be corrected by bringing the contact portion 90 into contact with the leading edge E1b or the trailing edge E2b of the upper blank 2b and accelerating or decelerating the upper blank 2b in the conveying direction T. Accordingly, two different operation modes O1, O2 can be provided. In the first operation mode O1, the contact portion 90 of the position correction device 86 contacts the trailing edge E2b of each upper blank 2b and acceleration is performed. In the second operation mode O2, the contact portion 90 of the position correction device contacts the leading edge E1b of each upper blank 2b and deceleration is performed. The position of the position correction device 86 may be different in the two operation modes O1 and O2. The position correction device 86 is preferably arranged at a position closer to the joining point J in the second correction mode O2 than in the first correction mode O1.

[0072] The position correction device 86 can be attached to the slide rail 95. Thereby, the position correction device 86 can be positioned according to the types of the operation modes O1 and O2 and according to the longitudinal length Lb of the upper blank 2b in the conveying direction T. Thereby, the contact portion 90 can be positioned so as to contact either the trailing edge E2b or the leading edge E1b of the upper blank 2b.

[0073] As shown in FIG. 4, the detection system 83 includes an upper transfer sensor 81b configured to detect the passage of the leading edge E1b in front of the upper blank 2b, and a lower transfer sensor 81a configured to detect the passage of the leading edge E1a in front of the lower blank 2a. The upper and lower transfer sensors 81b and 81a are arranged at a distance upstream from the joining point J.

[0074] As can be best seen from FIG. 6, the upper transfer sensor 81b is preferably attached to the protruding extension 87 of the position correction device 86. The protruding extension 87 can be coupled to the frame member 105 of the position correction device 86. The protruding extension 87 positions the upper transfer sensor 81b upstream of the cleat belt 88.

[0075] The control unit 91 is configured to receive detection signals from the upper transfer sensor 81b and the lower transfer sensor 81a and determine the actual positions Pb_act2 and Pa_act2 of the upper and lower blanks 2b and 2a by each transfer sensor 81a and 81b. The actual positions Pa_act2 and Pb_act2 of the upper and lower blanks 2a and 2b are positions in the conveying direction T at a predetermined moment. The predetermined moment can be defined in relation to the elapsed time since the transmission of the lower feeder discharge signal.

[0076] The rough positioning control configuration 36 further includes an upper rough positioning conveyor 78 configured to convey the upper blank 2b. The lower transfer conveyor 79 is configured to convey the lower blank 2a. The upper rough positioning conveyor 78 and the lower transfer conveyor 79 each carry the upper blank 2b and the lower blank 2a toward the branch point J.

[0077] The upper blank 2b has a conveying path Pb extending from the upper feeder device 32b to the branch point J, and the lower blank 2a has a conveying path Pa extending from the lower feeder device 32a to the branch point J.

[0078] The upper conveying path Pb has an upper conveyor system 31b including an upper alignment device 34b and an upper gauging conveyor 78. The lower conveying path Pa has a lower conveyor system 31a including a lower alignment device 34a and a lower conveying conveyor 79.

[0079] The gauging control configuration 36 is preferably configured to correct only the position of the upper blank 2b. Since the lower blank 2a also receives a gauging displacement deviation, the actual position Pa_act2 of each lower blank 2a at the lower transfer sensor 81a is selected as the reference position of the associated upper blank 2b. The position of each upper blank 2b is corrected by the position correction device 86 before the upper blank 2b reaches the joining point J.

[0080] The detection times from the respective transfer sensors 81a, 81b define the actual positions Pb_act2, Pa_act2 of the upper and lower blanks 2b, 2a. The lower transfer sensor 81a is arranged at a position upstream from the joining point J. The upper transfer sensor 81b is preferably attached to a protruding extension 87 coupled to the position correction device 86 so that the passage of the upper blank 2b can be detected before the upper blank 2b contacts the crete belt 88.

[0081] The control circuit 84 is configured to calculate a corresponding desired position Pb_des of the upper blank 2b at the transfer sensor 81b based on the actual position Pa_act2 of the lower blank 2a. The desired position Pb_des of the upper blank 2b is the position where the upper blank 2b is aligned with the lower blank 2a in the conveying direction T. The upper blank 2b being aligned with the lower blank 2a means that the upper blank 2b is carried so as to be superposed on the lower blank 2a at a position corresponding to a predetermined assembly position in the conveying direction T.

[0082] The control unit 91 is configured to calculate the desired position Pb_des of each upper blank 2b by determining the actual position Pa_act2 of each associated lower blank 2a and executing an algorithm stored in the memory 93.

[0083] Due to the inclined upper transport path Pb being longer than the lower transport path Pa, the actual transport speed Vb_act of the upper blank 2b upstream of the branch point J may be higher than the actual transport speed Va_act of the lower blank 2a.

[0084] Since the length of the upper transport path Pb may change according to the contact length Lcb of the extensible upper alignment device 34b, the theoretical transport speed Vb_t of the upper blank 2b can be calculated by the control unit 91 based on the position of the upper feeder device 32b. The position of the upper feeder device 32b can be determined from the longitudinal length La of the lower blank 2a. Therefore, the position of the upper feeder device 32 can determine the length of the upper transport path Pb and the theoretical transport speed Vb_t. Thereafter, the theoretical transport speed Vb_t can be calibrated using the detection system 83 so that the upper blank 2b arrives at an appropriate position relative to the lower blank 2a. The appropriate position enables position correction by the position correction device 86.

[0085] The position correction device 86 is configured to correct the position of each upper blank 2b by accelerating or decelerating it in the transport direction T.

[0086] The upper blank 2b is preferably conveyed with a selected displacement Δd_selected in the transport direction T. The selected displacement Δd_selected is a displacement distance intentionally selected relative to a preset estimated position Pb_reg of the upper blank 2b at the upper transfer sensor 81b. This selected displacement Δd_selected ensures that each upper blank 2b always arrives at the upper transfer sensor 81b with a displacement distance Δdb.

[0087] The selected displacement distance Δd_selected is selected to be an amount that can be corrected by the position correction device 86. The selected displacement distance Δd_selected is preferably between 10 and 15 mm.

[0088] This intentionally selected displacement distance Δd_selected is either to delay or to advance. Delaying means that each upper blank 2b always arrives at the transfer sensor 81b with an excessive delay with respect to the target position Pb_reg. Advancing means that each upper blank 2b always arrives at the transfer sensor 81b with an excessive speed with respect to the target position Pb_reg.

[0089] The selected displacement distance Δd_selected can result in selecting the actual transfer speed Vb_act of the upper blank 2b, such that the preset selected displacement Δd_selected always occurs at the position of the upper transfer sensor 81b.

[0090] In another advantageous embodiment, the release timing of the upper feeder device 32b can be selected such that the upper blank 2b is carried with the selected displacement Δd_selected. Thus, this displacement is already effective when the upper blank leaves the upper feeder device 32b. This time deviation is a time delay or a time advance of the upper blank 2b with respect to the target position Pb_reg of the upper blank 2b.

[0091] The upper feeder device 32b has a theoretical release time t_b_register such that the upper blank 2b is at the target position and is aligned with the lower blank 2a. Similarly, the lower feeder device has a theoretical release time t_b_register such that the discharge of the lower blank 2a is adjusted in time and is at the target position.

[0092] Therefore, the time deviation Δt_b is added to the theoretical release timing t_b_register of the upper blank 2b.

[0093] The actual release timing tb_actual of the upper blank 2b is selected as follows. [Number]

[0094] In this embodiment, the actual conveyance speed Vb_act of the upper blank 2b is selected such that the upper blank 2b is positioned at the estimated position theoretically, and thus reaches the upper transfer sensor 81b at the estimated position. The actual conveyance speed Vb_act of the upper blank 2b may be higher than the actual conveyance speed Va_actual of the lower blank 2a, but this is simply to correspond to the difference in length between the upper conveyance path Pb and the lower conveyance path Pa.

[0095] In the upper transfer sensor 81b, the displacement Δdb of the upper blank 2b with respect to the estimated position Pb_reg of the upper blank can be calculated from the arrival time of the upper blank 2b at the upper transfer sensor 81b. This is effective regardless of whether the upper blank 2b has a time deviation Δt_b or a conveyance speed that causes the selected displacement at the upper transfer sensor 81b.

[0096] This displacement Δdb includes the selected displacement Δd_selected, the feeder displacement error Δdb_feeder, and the conveyance displacement Δdb_transportation.

[0097] FIG. 9 shows a first operation mode O1 in which the upper blank 2b is conveyed with a time deviation Δt_b added in the form of a delay to the release timing tb_actual. Alternatively, the actual conveyance speed Vb_act is lower than the theoretical required speed Vb_t. As a result, a preset selected negative displacement Δd_selected is added to each upper blank 2b. Therefore, all the upper blanks 2b arrive at the upper transfer sensor 81b with a time delay.

[0098] Figure 10 shows the second operation mode O2, in which the blanks are carried with a time deviation Δt_b added in the form of advancement at the release timing tb_actual. Alternatively, the actual conveyance speed Vb_act is theoretically higher than the required speed Vb_t. As a result, a preset and selected positive displacement Δd_selected is added to each blank. Therefore, all the upper blanks 2b arrive at the upper transfer sensor 81b in advance in terms of time.

[0099] In the modes O1 and O2 shown in FIGS. 9 and 10, the upper blank 2b receives the time deviation Δt_b, and the selected displacement Δd_selected is already effective in the upper feeder device 32b. When the actual conveyance speed Vb_act is selected to create the selected displacement Δd_selected, the selected displacement Δd_selected is preferably gradual, and its full amount is effective at the upper transfer sensor 81b.

[0100] The detection system 83 can further include an upper feed sensor 85b disposed at a distance downstream of the upper feeder device 32b and a lower feed sensor 85a disposed at a distance downstream of the lower feeder device 32a.

[0101] The upper and lower feed sensors 85b, 85a detect the passage of the leading edges E1b, E1a of the upper and lower blanks 2b, 2a, respectively. The passage of the leading edges E1b, E1a of the upper and lower blanks 2b, 2a can be used to determine the actual positions Pb_act1, Pb_act1 of the blanks 2b, 2a at the respective feed sensors 85b, 85a and the time when they are discharged from the upper and lower feeder devices 32b, 32a. In an embodiment where a time deviation is given to the upper blank 2b, the feeder displacement Δdb_feeder and the actual position Pb_act1 of the upper blank 2b at the feed sensor 85b can be obtained by the following relationship.

Equation

[0102] The actual position Pa_act1 of the lower blank 2a and the feeder displacement Δda_feeder in the lower feed sensor 85a can be obtained according to the following relationship.

Equation

[0103] Based on the actual positions Pb_act1, Pb_act1 provided by the upper and lower feed sensors 85b, 85a, the initial relative displacement Δdb_initial of the upper blank 2b with respect to the lower blank 2a can be calculated. Based on the initial relative displacement, the preliminary necessary correction of the contact portion 90 on the crete belt 88 can be determined. Therefore,

Equation

[0104] This initial preliminary necessary correction Δdb_initial is convenient for calculation because the feeder displacements Δda_feeder, Δdb_feeder are often larger than the conveyance displacements Δda_transportation, Δdb_transportation. Based on the initial preliminary necessary correction amount Δdb_initial, the control unit 91 can determine whether the position correction device 86 can correct with respect to the initial preliminary necessary correction amount Δdb_initial. When the necessary correction amount Δdb_initial is larger than the correction threshold T_corr of the position correction device 86, the control unit 91 can generate a warning or a control signal for turning off the power of the converter 1.

[0105] The estimated displacement Δda of the lower blank 2a in the lower transfer sensor 81a is calculated from the difference between the detected actual position Pa_act2 and the corresponding estimated position Pa_reg2 of the lower blank 2a. Therefore, the following relationship applies.

Equation

[0106] Regarding the upper blank 2b, the estimated displacement Δdb of the upper blank with respect to the preset estimated position Pb_reg2 of the upper blank in the upper transfer sensor 81b is as follows.

Equation

[0107] Therefore, the displacement Δdb is the sum of the feeder estimated displacement Δd_feeder, the conveyance displacement, and a predetermined displacement Δd_selected selected for the upper blank 2b.

[0108] The relative displacement Δdb_total of the upper blank 2b with respect to the lower blank 2a in the transfer sensors 81a and 81b is obtained by subtracting the estimated displacement Δda of the lower blank 2a from the estimated displacement Δdb of the upper blank 2b.

[0109] Therefore, the total relative displacement Δdb_total between the upper blank 2b and the lower blank 2a at the positions of the upper and lower transfer sensors 81b and 81a can be calculated as follows.

Equation

[0110] The position correction device 86 is configured to apply a displacement correction Δc to all the blanks 2b in the conveyance direction T. The correction Δc is equal to the total relative displacement Δdb_total. In this way, the upper blank 2b is displaced to the desired position P_des_b determined by the control unit 91. Therefore,

Equation

[0111] In the first operation mode O1, the position correction device 86 is configured to accelerate the upper blank 2b in order to apply the position correction Δc to each blank 2b. In the first operation mode O1, the position correction device 86 is arranged such that the contact portion 90 contacts the trailing edge E2b of the upper blank 2b.

[0112] In the second operation mode O2, the position correction device 86 is configured to decelerate the upper blank 2b in order to apply a position correction Δc to each blank 2b. Accordingly, the position correction device 86 decelerates each upper blank 2b before arriving at the joining point J.

[0113] In the first operation mode O1, for the upper blank 2b having a short longitudinal length Lb, the position correction device 86 is preferably arranged closer to the joining point J than in the case of a longer blank 2b.

[0114] By providing the two operation modes O1, O2, the position correction device 86 can also be set to abut against the most suitable edge of the leading edge E1b and the trailing edge E2b. Ideally, the most suitable edge is a straight or uniform edge.

[0115] The position correction device 86 can further include a displacement motor 97 configured to automatically displace the position correction device 86 along the slide rail 95. The longitudinal position of the position correction device 86 is selected based on the type of correction mode O1, O2 and the longitudinal length Lb of the upper blank.

[0116] The blank joining module 10 further includes an adhesive device 100 disposed upstream of the joining point J. The adhesive device can include an adhesive tank, a pump, and a dispensing nozzle. Preferably, the adhesive device 100 is arranged to dispense the adhesive onto the upper side of the lower blank 2a such that the adhesive is positioned between the upper blank 2b and the lower blank 2a. The adhesive device 100 is preferably operated based on the detection time of the lower transfer sensor 81a.

Description of Reference Numerals

[0117] 2a Lower blank 2b Upper blank 31a Lower conveyor system 31b Upper conveyor system 32a Lower feeder device 32b Upper feeder device 36 Alignment control configuration 81b Upper transfer sensor 81a Lower transfer sensor 83 Detection system 86 Position correction device 91 Control unit 93 Memory

Claims

1. An upper feeder device (32b) configured to supply an upper blank (2b), a lower feeder device (32a) configured to supply a lower blank (2a), an upper conveyor system (31b) configured to convey the upper blank from the upper feeder device, and a lower conveyor system (31a) configured to convey the lower blank from the lower feeder device, a blank joining module comprising: The upper conveyor system and the lower conveyor system are configured to convey the upper blank and the lower blank toward a joining point (J) where the upper blank is positioned on the lower blank. The blank joining module includes an aiming control configuration (36) including a detection system (83) and a position correction device (86). The detection system includes an upper transfer sensor (81b) configured to detect the passage of the upper blank and a lower transfer sensor (81a) configured to detect the passage of the lower blank. The aiming control configuration further includes a control unit (91) and a memory (93). The control unit is configured to receive detection signals from the upper transfer sensor and the lower transfer sensor and calculate a total relative displacement (Δd b_total) between the upper blank and the lower blank. The control unit is further configured to operate the position correction device (86) to displace the upper blank so as to align with the lower blank and give a correction displacement (Δc) to the upper blank. A blank joining module.

2. The upper blank (2b) is carried at a selected displacement distance (Δd_selected), and each of the upper blanks is configured to be displaced with respect to a preset aiming position (Pb_reg2) in the upper transfer sensor (81b). The blank joining module according to claim 1.

3. The selected displacement distance (Δd_selected) is selected such that each of the upper blanks (2b) always reaches the position of the upper transfer sensor (81b) with the total relative displacement (Δdb_total) with respect to the lower blank (2a), and the position of each of the upper blanks (2b) is corrected by the position correction device (86). The blank joining module according to claim 2.

4. The selected displacement distance (Δd_selected) is selected such that each of the upper blanks requires correction in the same direction in the upper conveyance path (Pb). The blank joining module according to claim 2.

5. The blank joining module according to any one of claims 1 to 4, wherein only the position of the upper blank is corrected.

6. The lower transfer sensor is configured to detect the actual position (Pa_act2) of the lower blank before the upper transfer sensor detects the actual position (Pb_act2) of the upper blank. The blank joining module according to any one of claims 1 to 5.

7. The actual speed (Vb_act) of the upper blank is different from the actual speed (Va_act) of the lower blank. The blank joining module according to any one of claims 1 to 6.

8. The actual release timing (tb_actual) of the upper blank (2b) or the actual conveyance speed (Vb_act) of the upper blank (2b) is selected to give the upper blank the selected displacement (Δd_selected) with respect to the estimated position (Pb_reg) of the upper blank. The blank joining module according to any one of claims 1 to 8.

9. The position correction device includes a cleat belt having at least one contact portion (90), and the control unit is configured to position the contact portion in contact with the leading edge (E1b) or the trailing edge (E2b) of the upper blank (2b), and to correct the position of the upper blank (2b) in the conveyance direction. The blank joining module according to any one of claims 1 to 8.

10. The position correction device includes a housing shroud having an extension portion extending upstream in the transport direction (T) from the crete belt, and the upper transfer sensor is disposed on the protruding extension portion (87). The blank joining module according to any one of claims 1 to 9.

11. The memory includes a first set of operation instructions for a first operation mode (O1) configured such that the position correction device abuts against the trailing edge of the upper blank so that each of the upper blanks is accelerated by the position correction device, and a second set of operation instructions for a second operation mode (O2) configured such that the position correction device abuts against the leading edge of the upper blank so that each of the upper blanks is decelerated by the position correction device. The blank joining module according to claim 9 or 10.

12. The position correction device is coupled to a displacement mechanism attached to the structural frame (40) of the blank joining module, and the position correction device is displaceable in the transport direction so as to be movable to a first operation position in a first operation mode and to a second operation position in a second operation mode. The blank joining module according to claim 11.

13. The displacement mechanism includes a motor and a slide mechanism, and the control unit is configured to operate the motor to displace the position correction device according to the longitudinal length (La) of the upper blank and the type of the selected correction mode (O1, O2). The blank joining module according to claim 12.

14. The alignment control configuration further includes an upper feed sensor and a lower feed sensor configured to detect the passage of each of the upper blank and the lower blank, and the control unit is configured to determine an initial relative feeder displacement (Δdb_initial) from the difference in detection times, and the control unit is configured to issue a warning signal when the initial relative feeder displacement (Δdb_initial) is greater than a correction threshold (T_corr). The blank joining module according to any one of claims 1 to 13.

15. The upper conveyor system includes an upper alignment conveyor and a positioning conveyor. The upper alignment conveyor is connected to the positioning conveyor and an upper feeder. The upper feeder is movable in the longitudinal direction (L), and the upper alignment conveyor has a variable length. The blank joining module according to any one of claims 1 to 14.

16. The control unit is configured to change the release time and / or conveyance speed of the upper blank based on the length of the upper alignment conveyor. The blank joining module according to claim 15.

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