Sheet bundle stacking device

Abstract

To provide a sheet bundle stacking device which can easily ensure the cycle time of the sheet bundle stacking operation and requires a small installation space.SOLUTION: A sheet bundle stacking device has a horizontal fork 4 that moves in the front-rear direction, an upper belt 5 that extends in the front-rear direction along the upper surface of the horizontal fork 4, and a lower belt 6 that extends in the front-rear direction along the lower surface of the horizontal fork 4. In the sheet bundle stacking device, with a sheet bundle S placed on the upper surface of the upper belt 5 and the lower surface of the lower belt 6 pressed against the upper surface of the sheet pile T, the sheet bundle S falls from the upper surface of the upper belt 5 onto the top surface of the sheet pile T by moving the horizontal fork 4 from the forward position to the backward position while the upper belt 5 and the lower belt 6 travel forward along the upper and lower surfaces of the horizontal fork 4, thereby stacking the sheet bundle.SELECTED DRAWING: Figure 12

Description

[Technical Field]

[0001] The present invention relates to a sheet stack stacking device for stacking sheet bundles to form a pile of sheets. [Background technology]

[0002] Generally, when rectangular corrugated cardboard sheets are punched out with a die-cutter to form blank sheets for corrugated cardboard boxes, the blank sheets discharged from the die-cutter are stacked at the outlet of the die-cutter to form a stack of sheets. This stack of sheets is transported downstream on a conveyor line, and may be piled up on a pallet, plywood, or the like along the conveyor line to form a pile of sheets. In this case, conventionally, a person would often manually stack the stack of sheets on a pallet or the like.

[0003] However, stacking sheet bundles on a pallet or the like by hand requires a lot of labor.

[0004] On the other hand, a sheet stack stacking device that uses an articulated robot arm is known, which is capable of automatically stacking sheet stacks on a pallet or the like without manual labor (for example, Patent Document 1).

[0005] The sheet bundle stacking device of Patent Document 1 stacks up bundles of cardboard sheets by repeatedly grasping the bundle of cardboard sheets with a robot hand at the tip of a multi-joint robot arm, lifting the bundle of sheets, moving it through the air, and lowering it onto a pallet or the like placed downstream. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2019-127348 Summary of the Invention [Problem to be solved by the invention]

[0007] However, if an attempt is made to stack the sheet bundle discharged from the die cutter device on a pallet or the like using an articulated robot arm as in Patent Document 1, there is a risk that the cycle time will not be met.

[0008] That is, when stacking sheet bundles on a pallet or the like using an articulated robot arm, the robot hand at the tip of the articulated robot arm holds only one sheet bundle, so the operation of stacking sheet bundles must be repeated the same number of times as the number of sheet bundles. Therefore, for example, if a die-cutter performs a six-piece punching process in a cycle time of 24 seconds, the articulated robot arm must stack the sheet bundles in a cycle time of 4 seconds, but it is not easy to stack sheet bundles in such a short cycle time.

[0009] Furthermore, when a sheet bundle stacking device using an articulated robot arm as in Patent Document 1 is installed on the sheet bundle conveyance line downstream of the die cutter device, there is also the problem that it is difficult to secure the installation space.

[0010] That is, when a multi-joint robot arm is installed downstream of the die-cutter device to stack the sheet stacks discharged from the die-cutter device on a pallet or the like, the multi-joint robot arm rotates with a relatively large turning radius, so a relatively large installation space is required to prevent the robot arm from interfering with its surroundings, but it is difficult to secure such a large installation space on an existing conveyor line.

[0011] An object of the present invention is to provide a sheet stack stacking device that can easily ensure the cycle time for stacking sheet stacks and requires a small installation space. [Means for solving the problem]

[0012] In order to solve the above problems, the present invention provides a sheet stack stacking device having the following configuration. [Configuration 1] A sheet stack stacking device that receives a sheet stack formed by stacking sheets from an upstream side and stacks the sheet stack downstream to form a sheet pile, a horizontal fork that moves in the front-rear direction between a forward position located above the seat mountain and a backward position moved rearward from the forward position; an upper belt extending in the front-rear direction along an upper surface of the horizontal fork and wound around an upper belt front end pulley and an upper belt rear end pulley provided at the front end and rear end of the horizontal fork, respectively; a lower belt extending in the front-rear direction along the lower surface of the horizontal fork and wound around a lower belt front end pulley and a lower belt rear end pulley provided at the front end and rear end of the horizontal fork, respectively; With the sheet stack placed on the upper surface of the upper belt and the lower surface of the lower belt pressed against the upper surface of the sheet pile, the upper and lower belts are made to travel forward along the upper and lower surfaces of the horizontal fork while the horizontal fork is moved from the forward position to the retreated position, thereby dropping and stacking the sheet stack from the upper surface of the upper belt onto the upper surface of the sheet pile.

[0013] With this configuration, when the horizontal fork is moved from the forward position to the backward position, the upper belt travels forward along the upper surface of the horizontal fork, so that the portion of the upper belt carrying the sheet stack does not move forward or backward relative to the stationary system, and only the horizontal fork can move backward relative to the stationary system. As a result, the sheet stack placed on the upper surface of the upper belt can be dropped and piled up on the top of the pile of sheets directly below without losing its shape.

[0014] Furthermore, since it is possible to place a plurality of sheet bundles on the upper surface of the upper belt and stack the plurality of sheet bundles on the top of the sheet pile at once, it is easy to ensure the cycle time for stacking the sheet bundles.

[0015] Furthermore, when the horizontal fork is moved from the forward position to the backward position, the horizontal fork is not moved with its lower surface separated upward from the upper surface of the sheet pile, but rather the horizontal fork is moved with the lower belt on its lower surface pressed against the upper surface of the sheet pile, thereby reducing the falling distance of the sheet stack from the upper surface of the upper belt to the upper surface of the sheet pile and reducing the impact when it falls.

[0016] Furthermore, when the horizontal forks are moved from the forward position to the reverse position, the lower belts run forward along the undersides of the horizontal forks, so the portion of the lower belt pressed against the upper surface of the seat pile does not move forward or backward relative to the stationary system, and only the horizontal forks can move rearward relative to the stationary system. Therefore, even when the seat pile becomes high, the horizontal forks can be moved from the forward position to the reverse position while the lower belt presses the upper surface of the seat pile to prevent it from collapsing.

[0017] Furthermore, when this sheet stack stacking device is installed on a sheet stack conveying line, it can be installed so that the direction of movement of the horizontal fork is the same as the conveying direction of the conveying line when viewed from above, thereby making it possible to keep the installation space small.

[0018] [Configuration 2] A lower belt fixing bracket is provided below the horizontal fork, and its movement in the front-rear direction relative to the stationary system is restricted. The sheet bundle stacking device according to configuration 1, wherein the lower belt is stretched between the upper side of the lower belt front end pulley and the upper side of the lower belt rear end pulley, and the portion extending from the lower side of the lower belt front end pulley toward the lower belt rear end pulley and the portion extending from the lower side of the lower belt rear end pulley toward the lower belt front end pulley are each fixed to the lower belt fixing bracket.

[0019] With this configuration, because the lower belt is fixed to the lower belt fixing bracket, which restricts its movement in the front-to-rear direction relative to the stationary system, when the horizontal fork is moved from the forward position to the reverse position, the portion of the lower belt that extends along the underside of the horizontal fork moves forward relative to the horizontal fork but does not move in the front-to-rear direction relative to the stationary system. Therefore, when the horizontal fork is moved from the forward position to the reverse position, it is possible to reliably prevent the lower belt from moving in the front-to-rear direction relative to the upper surface of the seat crest, causing the seat crest to collapse.

[0020] Furthermore, the configuration for running the lower belt along the underside of the horizontal fork does not require a dedicated electric motor or the like to drive the lower belt, but rather uses a simple configuration in which the lower belt is fixed to a lower belt fixing bracket whose movement in the forward and backward directions relative to the stationary system is restricted, resulting in low cost.

[0021] [Configuration 3] The upper belt is formed in a circular shape so as to run around between the upper belt front end pulley and the upper belt rear end pulley, an upper belt drive motor for driving the upper belt is attached to a forward / backward moving frame that moves in the forward / backward direction integrally with the horizontal fork; The sheet bundle stacking device according to configuration 1 or 2, wherein the upper belt drive motor drives the upper belt so as to travel forward and transport the sheet bundle to a position corresponding to the pile of sheets when the sheet bundle supplied from the upstream side is placed on the upper surface of the upper belt, and drives the upper belt so as to travel forward relative to the horizontal fork at the same speed as the moving speed of the horizontal fork when the horizontal fork moves from the forward position to the backward position.

[0022] With this configuration, since the upper belt drive motor dedicated to driving the upper belt is attached to the front-rear moving frame that moves in the front-rear direction integrally with the horizontal fork, the running of the upper belt can be controlled independently from the control of the front-rear movement of the horizontal fork. Therefore, when a sheet bundle supplied from the upstream side is placed on the upper surface of the upper belt, the upper belt is driven as a conveyor belt that transports the sheet bundle supplied from the upstream side to a predetermined position on the horizontal fork, and then, when the horizontal fork is moved from the forward position to the backward position, the upper belt can be run relative to the horizontal fork so that the sheet bundle placed on the upper belt does not move in the front-rear direction relative to the stationary system.

[0023] [Configuration 4] The sheet bundle stacking device according to any one of configurations 1 to 3, wherein the upper belt front end pulley and the lower belt front end pulley are attached to the front ends of the horizontal forks so as to be aligned in the front-rear direction.

[0024] By adopting this configuration, the upper belt front end pulley and the lower belt front end pulley are aligned in the front-to-back direction, so it is possible to reduce the vertical distance from the upper surface of the upper belt wrapped around the upper belt front end pulley to the lower surface of the lower belt wrapped around the lower belt front end pulley, i.e., the falling distance of the sheet stack when the sheet stack placed on the upper surface of the upper belt is dropped onto the top of the sheet pile and stacked up.

[0025] [Configuration 5] A sheet bundle stacking device according to configuration 4, wherein a front end guide pulley is provided between the upper belt front end pulley and the lower belt front end pulley to guide the upper belt or the lower belt so that the upper belt and the lower belt do not come into contact with each other.

[0026] This configuration makes it possible to prevent the upper and lower belts from meandering due to contact between the belts. Specifically, when the upper belt front end pulley and the lower belt front end pulley are installed side by side in the front-to-back direction, there is a risk that the upper and lower belts will come into contact with each other between the upper belt front end pulley and the lower belt front end pulley. If the upper and lower belts run while in contact with each other, friction at the contact points could cause the upper and lower belts to meander. Therefore, providing a front end guide pulley between the upper and lower belt front end pulleys makes it possible to prevent the upper and lower belts from meandering due to contact between the belts.

[0027] [Configuration 6] the upper belt front end pulley, the lower belt front end pulley, and the front end guide pulley are arranged in the order of the upper belt front end pulley, the front end guide pulley, and the lower belt front end pulley from the rear side to the front side, The sheet stack stacking device according to configuration 5, wherein a portion of the lower belt extending from above the lower belt front end pulley toward the lower belt rear end pulley is wound around the lower side of the outer periphery of the front end guide pulley.

[0028] With this configuration, when the lower belt travels forward along the underside of the horizontal fork, the front guide pulley is rotated by contact with the lower belt, and the direction of rotation of the front guide pulley at that time is the direction that sends anything that comes into contact with the upper end of the front guide pulley forward. Therefore, when a stack of sheets is dropped from the upper surface of the upper belt onto the top of the sheet pile and stacked up, even if the underside of the sheet stack comes into contact with the front guide pulley, the contact with the front guide pulley does not hinder the dropping of the sheet stack, and the sheet stack can be dropped smoothly.

[0029] [Configuration 7] A sheet bundle stacking device according to configuration 6, wherein the lower belt front end pulley is positioned below the front end guide pulley so that the upper surface of the lower belt at the position of the upper end of the lower belt front end pulley is at a lower position than the position of the upper end of the front end guide pulley.

[0030] By adopting this configuration, when the sheet stack is dropped from the upper surface of the upper belt onto the upper surface of the sheet pile and piled up, the lower surface of the rear part of the sheet stack can be prevented from rubbing against the upper surface of the lower belt at the position of the upper end of the lower belt front end pulley.

[0031] [Configuration 8] 8. The sheet bundle stacking device according to any one of configurations 1 to 7, wherein the sheet bundle is a sheet bundle of cardboard sheets.

[0032] Here, the sheet stack of cardboard sheets can be a stack of rectangular cardboard sheets, or a stack of blank sheets for cardboard boxes formed by punching rectangular cardboard sheets with a die-cutter device. [Effects of the Invention]

[0033] The sheet stack stacking device of this invention can place multiple sheet stacks on the upper surface of the upper belt and stack the multiple sheet stacks on the top of the sheet pile at once, making it easy to ensure the cycle time for the sheet stack stacking operation. Furthermore, when the sheet stack stacking device of this invention is installed on a sheet stack conveying line, it can be installed so that the movement direction of the horizontal fork is the same as the conveying direction of the conveying line when viewed from above, thereby making it possible to keep the installation space small. [Brief explanation of the drawings]

[0034] [Figure 1] 1 is a top view of a sheet stack stacking device according to an embodiment of the present invention; FIG. [Figure 2] Enlarged view of part of Figure 1 [Figure 3] Cross-sectional view along line III-III in Figure 1 [Figure 4]Cross-sectional view along line IV-IV in Figure 1 [Figure 5] Front view of the sheet stack stacking device in Figure 1 [Figure 6] Cross-sectional view along line VI-IV in Figure 1 [Figure 7] An enlarged view of the front end portion of the horizontal fork in FIG. 3. [Figure 8] An enlarged view of the rear end portion of the horizontal fork in FIG. 3. [Figure 9] Cross-sectional view along line IX-IX in Figure 7 [Figure 10] FIG. 4 shows a state in which a plurality of sheet bundles are received on the upper surface of the upper belt shown in FIG. 3 and are transported by the upper belt to a predetermined position on the horizontal fork. [Figure 11] FIG. 11 shows the horizontal fork shown in FIG. 10 moved to a forward position. [Figure 12] 12 is a diagram showing the vicinity of the front end of the horizontal fork in a state where the horizontal fork shown in FIG. 11 is moved downward to press the lower belt against the upper surface of the seat peak. [Figure 13] 13 is a diagram showing the vicinity of the front end of the horizontal fork in a state where the portion of the upper belt along the upper surface of the horizontal fork is moved forward relative to the horizontal fork while the horizontal fork shown in FIG. 12 is moved horizontally backward, and the portion of the lower belt along the lower surface of the horizontal fork is moved forward relative to the horizontal fork. [Figure 14] FIG. 14 is a view showing the vicinity of the front end of the horizontal fork in a state where the horizontal fork shown in FIG. 13 is further moved rearward and the sheet stack is about to fall from the front end of the horizontal fork. [Figure 15] 12 shows the state in which the horizontal fork shown in FIG. 11 is moved to the retreated position and the sheet stack is dropped onto the top of the sheet pile from the horizontal fork and piled up. DETAILED DESCRIPTION OF THE INVENTION

[0035] 1 to 9 show a sheet stack stacking device according to an embodiment of the present invention. As shown in Fig. 1, this sheet stack stacking device has a fixed frame 1, a lifting frame 2 that moves up and down relative to the fixed frame 1 (a direction perpendicular to the plane of the paper in the figure), a front-rear moving frame 3 that moves back and forth relative to the lifting frame 2 (a left-right direction in the figure), a plurality of horizontal forks 4 attached to the front-rear moving frame 3, upper belts 5 that extend in the front-rear direction along the upper surfaces of the horizontal forks 4, and lower belts 6 that extend in the front-rear direction along the lower surfaces of the horizontal forks 4 (see Fig. 3).

[0036] As shown in FIG. 1, the fixed frame 1 has a pair of left and right front vertical frame portions 1a, a pair of left and right rear vertical frame portions 1b spaced apart rearward from the front vertical frame portions 1a, and horizontal frame portions (not shown) that connect these vertical frame portions to one another. The horizontal frame portions connect the upper ends of the left front vertical frame portion 1a and the left rear vertical frame portion 1b, the upper ends of the right front vertical frame portion 1a and the right rear vertical frame portion 1b, the upper ends of the left front vertical frame portion 1a and the right front vertical frame portion 1a, and the upper ends of the left rear vertical frame portion 1b and the right rear vertical frame portion 1b. The left and right front vertical frame portions 1a and the left and right rear vertical frame portions 1b are each formed like a column extending vertically (perpendicular to the plane of the paper in the figure), with their lower ends fixed to the floor.

[0037] The lifting frame 2 is formed in a rectangular frame shape having a pair of left and right side frame portions 2a extending in the front-to-rear direction, a front frame portion 2b connecting the front ends of the side frame portions 2a, and a rear frame portion 2c connecting the rear ends of the side frame portions 2a. Left and right front vertical frame portions 1a and left and right rear vertical frame portions 1b of the fixed frame 1 are arranged on both left and right sides of the lifting frame 2.

[0038] 2 and 5, guide members 8 (guide rollers in the figures) are attached via lifting brackets 7 to the front and rear end portions of the left and right side surfaces of the lifting frame 2, and each guide member 8 is supported so as to be movable in the vertical direction by lifting guide rails 9 that extend in the vertical direction and are attached to the left and right front vertical frame portions 1a and the left and right rear vertical frame portions 1b of the fixed frame 1, respectively. As a result, the lifting frame 2 is supported so as to be movable in the vertical direction while its movement in the front-to-back and left-to-right directions relative to the fixed frame 1 is restricted.

[0039] As shown in Figures 4 and 6, the fixed frame 1 is provided with a lifting drive mechanism 10 that moves the lifting frame 2 in the up and down direction. The lifting drive mechanism 10 has chains 11 that suspend and support the lifting frame 2, and a chain hoisting device (not shown) that winds up the chains 11. A total of four chains 11 are provided on the front, back, left, and right sides of the lifting frame 2, and the four chains 11 are connected to chain connecting fittings 12 (see Figure 1) attached at four locations, two locations at the front and two locations at the front of the left and right side frame portions 2a of the lifting frame 2. The chain hoisting device is configured to wind up (or unwind) the four chains 11 at the same speed, thereby raising and lowering the lifting frame 2 while keeping it horizontal.

[0040] As shown in Figures 2 and 3, the front-rear moving frame 3 is provided to extend in the left-right direction below the horizontal fork 4. As shown in Figures 2 and 4, side brackets 13 are fixed to both ends of the front-rear moving frame 3. A guide member 14 (a slider in the figure) is attached to each side bracket 13, and the guide members 14 are supported so as to be movable in the front-rear direction by horizontal guide rails 15 attached to the side frame portions 2a of the lifting frame 2 and extending in the front-rear direction. In this way, the front-rear moving frame 3 is supported so as to be movable in the front-rear direction while its movement in the up-down direction relative to the lifting frame 2 is restricted.

[0041] As shown in Figures 4 and 5, the lifting frame 2 is provided with a front-rear drive mechanism 16 that moves the front-rear moving frame 3 in the front-rear direction. As shown in Figure 4, the front-rear drive mechanism 16 includes a pair of front and rear pulleys 17, 18 attached to the lifting frame 2, a circular transmission belt 19 wound around the pair of front and rear pulleys 17, 18, and a front-rear drive electric motor 20 (see Figures 3 and 5) that rotates one of the pair of front and rear pulleys 17, 18 (here, the front pulley 17). A straight portion of the transmission belt 19 that runs between the pair of front and rear pulleys 17, 18 is connected to a belt connector 21 provided on the side bracket 13. When the pulley 17 is rotated by the driving force of the electric motor 20, the straight portion of the transmission belt 19 that runs between the pair of front and rear pulleys 17, 18 moves in the front-rear direction, and the front-rear moving frame 3 moves in the front-rear direction together with the transmission belt 19.

[0042] As shown in FIG. 4, a pair of front and rear pulleys 17, 18 and a transmission belt 19 wound around the pair of pulleys 17, 18 are provided symmetrically on both the left and right sides of the lifting frame 2. As shown in FIG. 5, an electric motor 20 is attached to the left-right center of the front frame portion 2b of the lifting frame 2. A center pulley 22, to which the rotation of the electric motor 20 is input, is also attached to the left-right center of the lifting frame 2. The center pulley 22 is connected to the left and right pulleys 17 via a rotating shaft 23 extending left and right from the center pulley 22. As a result, the driving force of the electric motor 20 is simultaneously transmitted to the left and right pulleys 17 via the center pulley 22 and the rotating shaft 23, so that the side brackets 13 at both left and right ends of the forward-backward moving frame 3 shown in FIG. 6 can always be moved forward and backward at the same speed.

[0043] As shown in Figure 2, a plurality of horizontal forks 4 are provided at intervals in the left-right direction (up-down direction in the figure). Each horizontal fork 4 is fixed to the forward-rear moving frame 3, so that when the forward-rear moving frame 3 moves in the forward-rear direction (left-right direction in the figure), each horizontal fork 4 moves in the forward-rear direction integrally with the forward-rear moving frame 3. Each horizontal fork 4 is supported so as to be movable in the forward-rear direction by guide rollers 24 (see Figure 7) attached via a lower pulley bracket to the front frame portion 2b of the lifting frame 2. Here, the horizontal fork 4 is movable in the forward-rear direction between a forward position (position shown in Figure 11) and a backward position (position shown in Figure 10) moved rearward from the forward position.

[0044] As shown in Figure 3, the horizontal fork 4 is a long member that extends horizontally in the front-to-rear direction (left-to-right direction in the figure), and has a horizontal upper surface against which the upper belt 5 slides and a horizontal lower surface against which the lower belt 6 slides.

[0045] 9, the horizontal fork 4 is formed in the shape of a hollow cylinder with a rectangular cross section, with a pair of upper and lower sides each being long sides and a pair of left and right sides each being short sides. Although it is possible to use a flat steel square pipe as the horizontal fork 4 with such a configuration, using a flat carbon or aluminum alloy square pipe is preferable because the horizontal fork 4 is lighter and the movement speed of the horizontal fork 4 can be increased (especially the movement speed when moving the horizontal fork 4 from the forward position to the reverse position, which will be described later).

[0046] 3, the upper belt 5 is wound around an upper belt front end pulley 25 provided at the front end of the horizontal fork 4, an upper belt rear end pulley 26 provided at the rear end of the horizontal fork 4, and a drive pulley 27 located on the rear lower side of the horizontal fork 4. The upper belt 5 is an endless belt formed in a circular shape (a belt with both ends in the longitudinal direction joined together), and runs around between the upper belt front end pulley 25 and the upper belt rear end pulley 26 by the driving force of an upper belt drive motor 28.

[0047] 6, a plurality of drive pulleys 27 are provided at intervals in the left-right direction corresponding to a plurality of lower belts 6 provided at intervals in the left-right direction, and the driving force of an upper belt drive motor 28 is input to a common pulley shaft 29 that rotates integrally with the plurality of drive pulleys 27. The upper belt drive motor 28 and pulley shaft 29 are attached to the front-rear moving frame 3 via a motor bracket 30 and a drive pulley bracket 31, respectively, and when the front-rear moving frame 3 moves in the front-rear direction, the upper belt drive motor 28 and drive pulley 27 move integrally with the front-rear moving frame 3 in the front-rear direction.

[0048] 3, the lower belt 6 is wound around a lower belt front end pulley 32 provided at the front end of the horizontal fork 4 and a lower belt rear end pulley 33 provided at the rear end of the horizontal fork 4. The lower belt 6 is an endless belt formed in a circular shape, and one point in the circumferential direction is fixed to a lower belt fixing bracket 34 provided on the underside of the horizontal fork 4.

[0049] The lower belt fixing bracket 34 is disposed below the front of the horizontal fork 4 when the horizontal fork 4 is in the retracted position (the position shown in FIG. 10). The lower belt fixing bracket 34 is attached to a lower pulley bracket 35 fixed to the front frame 2b of the lifting frame 2, and fixes the lower belt 6 by clamping a part of the longitudinal direction of the lower belt 6 between the lower belt fixing bracket 34 and the lower pulley bracket 35. The lower belt fixing bracket 34 is a member whose movement in the front-rear direction relative to a stationary system is restricted so that it does not move in the front-rear direction even when the horizontal fork 4 moves in the front-rear direction between the forward position (the position shown in FIG. 11) and the retracted position (the position shown in FIG. 10).

[0050] Here, an endless belt (a belt with both longitudinal ends joined together) is used as the lower belt 6 to make it easier to fix the lower belt 6 with the lower belt fixing bracket 34, but it is also possible to use a lower belt 6 with both longitudinal ends that are not joined together. In this case, one end and the other end of the lower belt 6 may be fixed with a common lower belt fixing bracket 34, but fixing the one end and the other end of the lower belt 6 with separate lower belt fixing brackets 34 arranged at a distance from each other in the front and rear makes the fixing work of the lower belt 6 easier.

[0051] 7, the upper belt front end pulley 25 and the lower belt front end pulley 32 are attached side by side in the front-to-rear direction to a front end pulley bracket 36 provided at the front end of the horizontal fork 4. A front end guide pulley 37 that guides the lower belt 6 is provided between the upper belt front end pulley 25 and the lower belt front end pulley 32. The upper belt front end pulley 25, the lower belt front end pulley 32, and the front end guide pulley 37 are arranged side by side from the rear side (the right side in the figure) to the front side (the left side in the figure) in the order of upper belt front end pulley 25, front end guide pulley 37, and lower belt front end pulley 32.

[0052] The upper belt front end pulley 25, the front end guide pulley 37, and the lower belt front end pulley 32 are arranged at an incline so that the positions of their respective upper ends gradually decrease from the rear side to the front side. That is, the front end guide pulley 37 is arranged lower than the upper belt front end pulley 25 so that the position of the upper end of the front end guide pulley 37 is lower than the upper surface of the upper belt 5 at the position of the upper end of the upper belt front end pulley 25. Furthermore, the lower belt front end pulley 32 is arranged lower than the front end guide pulley 37 so that the upper surface of the lower belt 6 at the position of the upper end of the lower belt front end pulley 32 is lower than the position of the upper end of the front end guide pulley 37.

[0053] 8, the upper belt rear end pulley 26 and the lower belt rear end pulley 33 are attached to a rear end pulley bracket 38 provided at the rear end of the horizontal fork 4. In addition, an upper belt guide pulley 39 that guides the upper belt 5, an upper belt meandering adjustment pulley 40 that adjusts the meandering of the upper belt 5, and a lower belt guide pulley 41 that guides the lower belt 6 are attached to the rear end pulley bracket 38.

[0054] 7 and 8, the upper belt 5 is installed so as to be stretched straight between the upper end of the upper belt front end pulley 25 and the upper end of the upper belt rear end pulley 26, and the portion stretched between the two pulleys 25, 26 is in sliding contact with the upper surface of the horizontal fork 4. Also, as shown in FIG. 7, the portion of the upper belt 5 extending from the underside of the upper belt front end pulley 25 toward the upper belt rear end pulley 26 passes through the inside of the horizontal fork 4 and passes through the horizontal fork 4 in the front-to-rear direction. The horizontal fork 4 is provided with a partition member 42 that separates the inside of the horizontal fork 4 into upper and lower sections so that the upper belt 5 does not come into contact with the lower belt 6.

[0055] As shown in Figures 7 and 8, the lower belt 6 passes above the lower belt front end pulley 32 and above the lower belt rear end pulley 33 and is stretched between the two pulleys 32, 33, and the portion extending from the underside of the lower belt front end pulley 32 shown in Figure 7 toward the lower belt rear end pulley 33 shown in Figure 8 and the portion extending from the underside of the lower belt rear end pulley 33 shown in Figure 8 toward the lower belt front end pulley 32 shown in Figure 7 are each fixed to the lower belt fixing bracket 34 shown in Figure 7.

[0056] 7, the portion of the lower belt 6 that extends from above the lower belt front end pulley 32 toward the lower belt rear end pulley 33 (see FIG. 8) passes through the inside of the horizontal fork 4 and passes through the horizontal fork 4 in the front-to-rear direction. Here, the portion of the lower belt 6 that extends from above the lower belt front end pulley 32 toward the lower belt rear end pulley 33 is wrapped around the underside of the outer periphery of the front end guide pulley 37 midway, thereby adjusting the running position of the lower belt 6 so that the upper belt 5 and the lower belt 6 do not come into contact with each other.

[0057] As shown in Fig. 7, a first lower guide pulley 43 that guides the portion of the lower belt 6 that extends from the position where it is fixed to the lower belt fixing bracket 34 toward the upper belt front end pulley 25, and a second lower guide pulley 44 that guides the portion of the lower belt 6 that extends from the position where it is fixed to the lower belt fixing bracket 34 toward the upper belt rear end pulley 26 (see Fig. 8) are provided below the horizontal fork 4. The first lower guide pulley 43 and the second lower guide pulley 44 are located below the front of the horizontal fork 4 when the horizontal fork 4 is in the retracted position (the position shown in Fig. 10).

[0058] The first lower guide pulley 43 and the second lower guide pulley 44 are attached to the lower pulley bracket 35 at a distance from each other in the front and rear, and the guide roller 24 is disposed between the first lower guide pulley 43 and the second lower guide pulley 44. This makes it possible to support the lower surface of the horizontal fork 4 directly with the guide roller 24 without using the lower belt 6.

[0059] The portion of the lower belt 6 extending from the fixed position on the lower belt fixing bracket 34 to the side of the upper belt front end pulley 25 is wound around the upper side of the first lower guide pulley 43. The first lower guide pulley 43 is disposed near the lower surface of the horizontal fork 4 so that the portion of the lower belt 6 extending from the upper end position of the first lower guide pulley 43 to the side of the upper belt front end pulley 25 runs horizontally along the lower surface of the horizontal fork 4.

[0060] Similarly, the portion of the lower belt 6 extending from the fixed position on the lower belt fixing bracket 34 to the side of the upper belt rear end pulley 26 (see FIG. 8) is wound around the upper side of the second lower guide pulley 44. The second lower guide pulley 44 is disposed near the lower surface of the horizontal fork 4 so that the portion of the lower belt 6 extending from the upper end position of the second lower guide pulley 44 to the side of the upper belt rear end pulley 26 (see FIG. 8) runs horizontally along the lower surface of the horizontal fork 4.

[0061] An example of operation in which the sheet stack stacking device described above is used to stack a sheet stack S of cardboard sheets supplied from the upstream side to the downstream side to form a sheet pile T will be described below.

[0062] First, as shown in Fig. 10, with the horizontal fork 4 in the retracted position, a sheet stack S supplied from an adjacent transfer conveyor (not shown) on the upstream side (right side in the figure) is placed on the upper surface of the upper belt 5. At this time, the upper belt drive motor 28 (see Fig. 6) drives the drive pulley 27, causing the portion of the upper belt 5 shown in Fig. 10 that runs along the upper surface of the horizontal fork 4 to travel forward, and the sheet stack S supplied from the upstream side is received on the upper surface of the upper belt 5. Thereafter, the portion of the upper belt 5 that runs along the upper surface of the horizontal fork 4 further runs forward, thereby transporting the sheet stack S placed on the upper belt 5 to a predetermined position on the horizontal fork 4 (a position that will be directly above the stack of sheets T that is being formed on the downstream side when the horizontal fork 4 is moved to the advanced position, as shown in Fig. 11).

[0063] Next, the electric motor 20 (see FIGS. 3 and 5) for forward and backward drive is operated to move the horizontal fork 4 from the retracted position (the position shown in FIG. 10) to the forward position (the position shown in FIG. 11). Here, as shown in FIG. 11, the vertical position of the lifting frame 2 is adjusted in advance by the lifting drive device (see FIGS. 4 and 6) so that when the horizontal fork 4 is moved to the forward position, the lower surface of the horizontal fork 4 is positioned a predetermined height higher than the upper surface of the sheet pile T that is being formed downstream. When the horizontal fork 4 is moved to the forward position, as shown in FIG. 11, the horizontal fork 4 is positioned above the sheet pile T, and the sheet stack S and the sheet pile T are aligned vertically.

[0064] Thereafter, as shown in FIG. 12, the lifting frame 2 is lowered by the lifting drive device (see FIGS. 4 and 6) until the lower surface of the lower belt 6 is pressed against the upper surface of the pile of sheets T.

[0065] Thereafter, the electric motor 20 for forward / backward drive (see FIGS. 3 and 5) is operated to move the horizontal fork 4 from the forward position (the position shown in FIG. 11) to the backward position (the position shown in FIG. 15). When the horizontal fork 4 moves from the forward position to the backward position, as shown in FIGS. 12 to 15, the upper belt drive motor 28 (see FIG. 6) drives the upper belt 5 so that the portion of the upper belt 5 along the upper surface of the horizontal fork 4 (i.e., the portion on which the sheet stack S is placed) moves forward relative to the horizontal fork 4 at the same speed as the moving speed of the horizontal fork 4, preventing the portion of the upper belt 5 along the upper surface of the horizontal fork 4 (i.e., the portion on which the sheet stack S is placed) from moving forward / backward relative to the stationary system. At this time, the portion of the lower belt 6 along the lower surface of the horizontal fork 4 (i.e., the portion pressed against the upper surface of the sheet pile T) is fixed by the lower belt fixing bracket 34 as shown in FIG. 11, and therefore moves forward relative to the horizontal fork 4 but does not move forward / backward relative to the stationary system. As a result, as shown in Figures 12 to 15, without moving the sheet stack S and the sheet pile T above and below the horizontal fork 4 in the forward / backward direction relative to the stationary system, only the horizontal fork 4 can be pulled out from between the sheet stack S and the sheet pile T, and the sheet stack S can be dropped onto the top surface of the sheet pile T and stacked up.

[0066] By repeating the above-described operations, this sheet bundle stacking device stacks the sheet bundles S of cardboard sheets supplied from the upstream side in order downstream to form a pile of sheets T. Here, the sheet bundle S of cardboard sheets supplied from the upstream side is, for example, a sheet bundle S made by stacking rectangular cardboard sheets, or a sheet bundle S made by stacking blank sheets for cardboard boxes formed by punching rectangular cardboard sheets with a die cutter device. The sheet bundle S is an unbound sheet bundle that is not bound with binding strings or the like.

[0067] In this sheet bundle stacking device, when the horizontal fork 4 is moved from the forward position (the position shown in FIG. 11) to the retracted position (the position shown in FIG. 15), the upper belt 5 runs forward along the upper surface of the horizontal fork 4, so it is possible to move only the horizontal fork 4 backward relative to the stationary system without moving the portion of the upper belt 5 on which the sheet bundle S is placed (the portion of the upper belt 5 extending along the upper surface of the horizontal fork 4) in the front-to-rear direction relative to the stationary system. Therefore, the sheet bundle S placed on the upper surface of the upper belt 5 as shown in FIG. 11 can be dropped and stacked on the top surface of the sheet pile T directly below, as shown in FIG. 15, without losing the shape of the sheet bundle S.

[0068] In addition, this sheet bundle stacking device can place multiple sheet bundles S on the upper surface of the upper belt 5 as shown in Figure 11, and stack the multiple sheet bundles S on the upper surface of the sheet pile T at once as shown in Figure 15, making it easy to ensure the cycle time for the sheet bundle S stacking operation.

[0069] Furthermore, when this sheet stack stacking device moves the horizontal fork 4 shown in Figure 11 from the forward position to the backward position, it does not move the horizontal fork 4 with the lower surface of the horizontal fork 4 separated upward from the upper surface of the sheet pile T, but rather moves the horizontal fork 4 with the lower belt 6 on the lower surface of the horizontal fork 4 pressed against the upper surface of the sheet pile T, as shown in Figures 12 and 13. This reduces the falling distance of the sheet stack S from the upper surface of the upper belt 5 to the upper surface of the sheet pile T, making it possible to reduce the impact when it falls.

[0070] 11 from the forward position to the backward position, as shown in Figures 12 and 13, the sheet stack stacking device causes the lower belt 6 to travel forward along the underside of the horizontal fork 4, and moves only the horizontal fork 4 backward relative to the stationary system without moving the portion of the lower belt 6 that is pressed against the upper surface of the sheet pile T (the portion of the lower belt 6 that extends along the underside of the horizontal fork 4) in the front-to-rear direction relative to the stationary system. Therefore, even when the sheet pile T shown in Figure 11 becomes high, it is possible to move the horizontal fork 4 from the forward position to the backward position while pressing the upper surface of the sheet pile T with the lower belt 6 so that the sheet pile T does not collapse.

[0071] 11, in this sheet stack stacking device, the lower belt 6 is fixed to the lower belt fixing bracket 34, whose movement in the front-rear direction relative to the stationary system is restricted, so that when the horizontal fork 4 is moved from the forward position (the position shown in FIG. 11) to the retracted position (the position shown in FIG. 15), the portion of the lower belt 6 extending along the underside of the horizontal fork 4 moves forward relative to the horizontal fork 4 but does not move in the front-rear direction relative to the stationary system. Therefore, when the horizontal fork 4 is moved from the forward position to the retracted position, it is possible to reliably prevent the lower belt 6 from moving in the front-rear direction relative to the upper surface of the sheet pile T, causing the sheet pile T to collapse.

[0072] Furthermore, this sheet bundle stacking device does not have a dedicated electric motor or the like for driving the lower belt 6, but rather employs a simple configuration in which the lower belt 6 is fixed to a lower belt fixing bracket 34, as shown in FIG. 11, whose movement in the forward and backward directions relative to a stationary system is restricted, as a configuration for running the lower belt 6 forward along the underside of the horizontal fork 4 when the horizontal fork 4 is moved from the forward position (the position shown in FIG. 11) to the backward position (the position shown in FIG. 15), resulting in low cost.

[0073] 3, in this sheet stack stacking device, a dedicated upper belt drive motor 28 for driving the upper belt 5 is attached to the front-rear moving frame 3 that moves in the front-rear direction integrally with the horizontal fork 4, so that the running of the upper belt 5 can be controlled independently of the control of the front-rear movement of the horizontal fork 4. Therefore, as shown in Fig. 10, when a sheet stack S supplied from the upstream side is placed on the upper surface of the upper belt 5, the upper belt 5 is driven as a conveyor belt that transports the sheet stack S supplied from the upstream side (the right side in the figure) to a predetermined position on the horizontal fork 4 (the position indicated by the dashed dotted line in the figure), and thereafter, when the horizontal fork 4 is moved from the forward position to the backward position as shown in Figs. 11 and 15, the upper belt 5 can be run relative to the horizontal fork 4 so that the sheet stack S placed on the upper belt 5 does not move in the front-rear direction relative to the stationary system.

[0074] In addition, as shown in Figure 7, this sheet bundle stacking device has the upper belt front end pulley 25 and the lower belt front end pulley 32 aligned in the front-to-rear direction, so it is possible to keep short the vertical distance from the upper surface of the upper belt 5 wound around the upper belt front end pulley 25 to the lower surface of the lower belt 6 wound around the lower belt front end pulley 32, that is, the falling distance of the sheet bundle S placed on the upper surface of the upper belt 5 when it is dropped onto the top surface of the sheet pile T and stacked, as shown in Figures 13 and 14.

[0075] 7, this sheet bundle stacking device has a front end guide pulley 37 provided between the upper belt front end pulley 25 and the lower belt front end pulley 32, which can prevent the upper belt 5 and the lower belt 6 from meandering due to contact between the belts. That is, when the upper belt front end pulley 25 and the lower belt front end pulley 32 are installed side by side in the front-to-rear direction, the upper belt 5 and the lower belt 6 may come into contact with each other between the upper belt front end pulley 25 and the lower belt front end pulley 32. If the upper belt 5 and the lower belt 6 run while contacting each other, friction at the contact points may cause the upper belt 5 and the lower belt 6 to meander. Therefore, by providing the front end guide pulley 37 between the upper belt front end pulley 25 and the lower belt front end pulley 32, it can prevent the upper belt 5 and the lower belt 6 from meandering due to contact between the belts.

[0076] 7, in this sheet bundle stacking device, the portion of the lower belt 6 extending from above the lower belt front end pulley 32 toward the lower belt rear end pulley 33 is wrapped around the underside of the outer periphery of the front end guide pulley 37, so that when the lower belt 6 is made to run forward along the underside of the horizontal fork 4 as shown in FIGS. 12 to 14, the front end guide pulley 37 is driven and rotated by contact with the lower belt 6, and the direction of rotation of the front end guide pulley 37 at that time is the direction in which anything that comes into contact with the upper end of the front end guide pulley 37 is sent forward. Therefore, as shown in FIG. 14, when the sheet bundle S is dropped from the upper surface of the upper belt 5 onto the top surface of the sheet pile T to be stacked, even if the lower surface of the sheet bundle S comes into contact with the front end guide pulley 37, the falling action of the sheet bundle S is not hindered by the contact with the front end guide pulley 37, and the sheet bundle S can be smoothly dropped.

[0077] In addition, as shown in FIG. 7, in this sheet bundle stacking device, the lower belt front end pulley 32 is positioned lower than the front end guide pulley 37, so that when the sheet bundle S is dropped from the upper surface of the upper belt 5 onto the upper surface of the sheet pile T and stacked, as shown in FIG. 14, the lower surface of the rear part of the sheet bundle S can be prevented from rubbing against the upper surface of the lower belt 6 at the upper end position of the lower belt front end pulley 32.

[0078] Furthermore, when this sheet stack stacking device is installed on a conveying line for sheet stacks S, it is possible to reduce the installation space by installing it so that the movement direction of the horizontal fork 4 (left and right in the figure) is the same as the conveying direction of the conveying line when viewed from above, as shown in Figure 1.

[0079] 7, the upper belt front end pulley 25, the front end guide pulley 37, and the lower belt front end pulley 32 are arranged in this order from the rear to the front, but these pulleys may also be arranged in this order from the rear to the front: the lower belt front end pulley 32, the front end guide pulley 37, and the upper belt front end pulley 25. In this case, the portion of the front end guide pulley 37 that extends from below the upper belt front end pulley 25 toward the lower belt front end pulley 32 may be wound around the upper side of the outer periphery of the front end guide pulley 37, thereby adjusting the running position of the upper belt 5 so that the upper belt 5 and the lower belt 6 do not come into contact with each other.

[0080] In addition, in the above embodiment, as shown in Figure 1, by providing an upper belt 5 and a lower belt 6 on each of multiple horizontal forks 4 arranged in parallel and spaced apart in the left-right direction, the distance between adjacent upper belts 5 in the left-right direction is narrowed, making it possible to stably stack even sheet stacks S with small left-right width dimensions.However, it is also possible to configure the multiple horizontal forks 4 arranged in parallel and spaced apart in the left-right direction so that every other horizontal fork 4 is provided with only an upper belt 5, and the other every other horizontal fork 4 is provided with only a lower belt 6.

[0081] In the above embodiment, a sheet bundle stacking device that stacks a sheet bundle S of cardboard sheets has been described as an example, but the present invention can also be applied to a sheet bundle stacking device that stacks a sheet bundle S other than cardboard sheets. [Explanation of symbols]

[0082] 3. Forward / backward moving frame 4 horizontal forks 5 Upper Belt 6 Lower Belt 25 Upper belt front end pulley 26 Upper belt rear end pulley 28 Upper belt drive motor 32 Lower belt front end pulley 33 Lower belt rear end pulley 34 Lower belt fixing bracket 37 Front end guide pulley S sheet stack T-sheet mountain

Claims

1. A sheet stack stacking device that receives a sheet stack (S) of stacked sheets from an upstream side and stacks the sheet stack (S) downstream to form a sheet pile (T), a horizontal fork (4) that moves in the front-rear direction between a forward position located above the seat mountain (T) and a backward position moved rearward from the forward position; an upper belt (5) extending in the front-rear direction along the upper surface of the horizontal fork (4) and wound around an upper belt front end pulley (25) and an upper belt rear end pulley (26) provided at the front end and rear end of the horizontal fork (4), respectively; a lower belt (6) extending in the front-rear direction along the lower surface of the horizontal fork (4) and wound around a lower belt front end pulley (32) and a lower belt rear end pulley (33) provided at the front end and rear end of the horizontal fork (4), respectively; With the sheet stack (S) placed on the upper surface of the upper belt (5) and the lower surface of the lower belt (6) pressed against the upper surface of the sheet pile (T), the upper belt (5) and the lower belt (6) are made to travel forward along the upper and lower surfaces of the horizontal fork (4) while the horizontal fork (4) is moved from the forward position to the backward position, thereby dropping and stacking the sheet stack (S) from the upper surface of the upper belt (5) onto the upper surface of the sheet pile (T).

2. A lower belt fixing bracket (34) is provided below the horizontal fork (4), and its movement in the front-rear direction relative to the stationary system is restricted.

2. The sheet bundle stacking device according to claim 1, wherein the lower belt (6) is stretched between the upper side of the lower belt front end pulley (32) and the upper side of the lower belt rear end pulley (33), and a portion extending from the lower side of the lower belt front end pulley (32) toward the lower belt rear end pulley (33) and a portion extending from the lower side of the lower belt rear end pulley (33) toward the lower belt front end pulley (32) are each fixed to the lower belt fixing bracket (34).

3. The upper belt (5) is formed in a circular shape so as to run around between the upper belt front end pulley (25) and the upper belt rear end pulley (26), An upper belt drive motor (28) that drives the upper belt (5) is attached to a forward / backward moving frame (3) that moves forward and backward together with the horizontal fork (4), 3. The sheet bundle stacking device according to claim 1, wherein the upper belt drive motor (28) drives the upper belt (5) so as to move the upper belt (5) forward and transport the sheet bundle (S) to a predetermined position on the horizontal fork (4) when the sheet bundle (S) supplied from the upstream side is placed on the upper surface of the upper belt (5), and drives the upper belt (5) so as to move the upper belt (5) forward relative to the horizontal fork (4) at the same speed as the movement speed of the horizontal fork (4) when the horizontal fork (4) moves from the forward position to the backward position.

4. 3. The sheet stack stacking device according to claim 1, wherein the upper belt front end pulley (25) and the lower belt front end pulley (32) are attached to the front end of the horizontal fork (4) in a line in the front-rear direction.

5. 5. The sheet bundle stacking device according to claim 4, wherein a front end guide pulley (37) is provided between the upper belt front end pulley (25) and the lower belt front end pulley (32) to guide the upper belt (5) or the lower belt (6) so that the upper belt (5) and the lower belt (6) do not come into contact with each other.

6. The upper belt front end pulley (25), the lower belt front end pulley (32), and the front end guide pulley (37) are arranged in the order of the upper belt front end pulley (25), the front end guide pulley (37), and the lower belt front end pulley (32) from the rear side to the front side, 6. A sheet stack stacking device according to claim 5, wherein the portion of the lower belt (6) extending from above the lower belt front end pulley (32) toward the lower belt rear end pulley (33) is wound around the lower side of the outer periphery of the front end guide pulley (37).

7. 7. A sheet stack stacking device according to claim 6, wherein the lower belt front end pulley (32) is positioned below the front end guide pulley (37) so that the upper surface of the lower belt (6) at the upper end position of the lower belt front end pulley (32) is lower than the upper end position of the front end guide pulley (37).

8. 3. The sheet stack stacking device according to claim 1, wherein the sheet stack (S) is a sheet stack of cardboard sheets.

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