JPH0536296B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention comprises a magazine for stacking and holding a large number of flatly folded cartons, and a suction cup for sucking and taking out cartons one by one from the magazine at a predetermined position from the magazine. A rotary conveyance mechanism that moves the carton along a trajectory to a conveyance path, a conveyance mechanism that conveys the rectangularly opened carton along the horizontal conveyance path toward the packaging machine, and a folding means that compresses the opened carton in the vertical direction. The folded carton is compressed in the conveying direction and reopened by re-opening means, and the carton taken out from the magazine as the suction cup moves is transferred to the conveyance path along the movement trajectory of the suction cup. The present invention relates to a carton assembling device that opens a carton in a rectangular shape, and folds and reopens the opened carton while transporting it along a conveyance path.

<Prior art> Conventionally, as a carton assembly device of this type, as disclosed in Japanese Patent Application Laid-Open No. 61-60420, a rotary conveying mechanism has three planetary gear trains meshing with the outer periphery of a fixed gear. A suction cup is connected to the outer end gear of each planetary gear train, and a large number of pushers are set up at equal intervals by the width of the cartons in the conveying direction on a chain conveyor driven in synchronization with the rotary conveying mechanism. Each planetary gear train rotates along the outer periphery of the fixed gear to move each suction cup in a substantially equilateral triangular adduction trochoid locus, thereby sucking a carton from the magazine at its first vertex. At the same time, the folded edge of the carton is brought into pressure-sliding contact with a pusher moving horizontally at a constant speed at the second vertex, and the carton is gradually opened.The adsorption of the carton is released, and the adjacent pushers are used to pull the carton on both sides. There are some that are transported while holding the surface in an upright position.

Furthermore, as disclosed in, for example, Japanese Patent Laid-Open No. 59-26833, the rotary conveyance mechanism changes the top portion of the carton introduction into a substantially U-shape using a cam mechanism, thereby reducing the time required to introduce the cartons onto the conveyance path. There are some that can be doubled to make them faster.

Furthermore, as disclosed in, for example, Japanese Patent Application Laid-Open No. 53-140777, a rotary conveying mechanism has a suction cup and a suction device disposed in close proximity to each other to attract adjacent surfaces of cartons, and the carton is taken out from the magazine by the suction cup. After that, the carton is forcibly opened into a rectangular shape by adsorbing the suction device and positioning it at right angles to the suction cup, and the carton is conveyed while being held upright by being sandwiched between the pushers of a chain conveyor that moves horizontally at a constant speed. There is.

Furthermore, as disclosed in Japanese Utility Model Application Publication No. 59-26709, for example, a carton taken out from a magazine is suctioned and held on a conveyance path by a suction cup, then pushed by a pusher of a chain conveyor, and then moved by an upwardly moved inclined guide. At the same time as the upper folding edge of the carton is raised and hits the stopper,
The inclined guide moves downward under the conveyance path, and then the pusher pushes the carton between it and the stopper to open the carton in a rectangular shape, and from this opening state, the swinging lever swings toward the upstream side of the conveyance path to open the carton. By abutting against the top surface of the carton, the carton is forcibly folded in the opposite direction to the folding direction in which it was folded in the magazine, and as a result, the pusher falls to the upstream side of the conveyance path, and then the pusher collides with the lower end of the stopper. In some cases, the cartons are reopened after being passed through the reversely folded cartons between vertically parallel regulation rails that are continuously arranged.

<Problems to be Solved by the Invention> However, with such conventional carton assembly methods and devices, in the case of JP-A-61-60420 and JP-A-53-140777, the folding edge of the carton is Because it is necessary to precisely match the timing of the movement locus and the horizontal movement of the chain conveyor's pusher, the adjustment work is difficult and troublesome. If the carton is introduced in a short time during the pusher at the top of the trochoidal trajectory, there is a problem in that there is not enough time to fully open the carton in a square shape, and the best opening conditions cannot be expected. .

This can be done by lengthening the introduction time of the carton as in JP-A No. 59-26833, or by
It is clear from the fact that the carton is forcibly opened in a rectangular shape as in Publication No. 140777, but in these systems, the structure of the rotary conveyance mechanism is very complicated, which not only increases the cost but also reduces the overall cost of the device. There is a problem with increasing the size.

In the case of Utility Model Application Publication No. 59-26709, a carton is sandwiched between a pusher and a stopper to open it in a rectangular shape by vertical movement of an inclined guide, and a swinging lever is abutted against the opened carton to forcibly open the carton. If you attempt to open or fold the carton into a rectangular shape at a rapid timing, excessive force will be applied to the carton and the surface of the carton will be easily damaged, reducing the product value and causing a large amount of cartons to be folded in a short period of time. It cannot be folded, is not suitable for high-speed operation, has a complicated structure, increases cost, and increases the size of the entire device.

Also, JP-A-61-60420 and JP-A-53-
In the case of Publication No. 140777 and Japanese Utility Model Application Publication No. 59-26709, the conveyance mechanism conveys the carton to the cartoning machine with the flaps protruding in the left and right directions orthogonal to the conveyance direction, so the left and right width of the conveyance mechanism Not only is it not possible to make the dimensions more compact, but it is also impossible to place the filling conveyor of the cartoning machine close to the cylindrical part of the opened carton, which increases the size of the entire device and makes it difficult to move away from the filling conveyor. The stroke of the pusher for filling the contents, which is disposed so as to move forward and backward toward the cylindrical portion of the carton, also needs to be longer by the protruding dimension of the flap, resulting in the problem that it takes time to fill the contents.

Furthermore, since the contents are filled with the flaps protruding in the left-right direction perpendicular to the conveyance direction, if the flaps are even slightly inclined inward, the flaps will be rolled up when filling the contents and the contents will be securely filled. There is a problem that it may not be filled.

Therefore, in order to solve this problem, while transporting the vertically folded cartons using a transport mechanism as disclosed in Japanese Patent Application Laid-open No. 48-65076,
It is conceivable that the flaps are expanded vertically and folded outward at 90 degrees by abutting the flaps against an inclined guide that gradually slopes vertically toward the downstream side in the conveyance direction.

However, in this case, when the carton is in a folded state, the flaps that protrude from the carton also overlap in the vertical direction, so especially if the protruding lengths of the flaps that overlap vertically are approximately the same, it is necessary to tilt these flaps. It is difficult to sort and expand the upper flap upwards and the lower flap downwards by simply hitting the guide.
The problem is that these flaps cannot be folded outwards accurately.

In view of such conventional circumstances, the present invention allows the carton to be folded smoothly by simply moving the carton using a suction cup and transporting it horizontally while reliably opening the carton in a rectangular shape without interlocking with a moving body.
The purpose is to accurately sort vertically stacked flaps and fold them outward.

<Means for Solving the Problems> The technical means taken by the present invention to solve the above problems is to erect a fixed inclined guide on the conveyance path so that its inclined surface faces downstream in the conveyance direction, and to The plane is inclined at an angle that gradually approaches and intersects the moving locus of the lower folding edge of the carton as it moves toward the conveyance path and the downstream side, and the folding means is moved downstream from the fixed inclined guide and gradually becomes horizontal as it moves downstream in the conveyance direction. A flap folding means is disposed horizontally parallel to the conveyance path from near the folding means to the upstream side of the re-opening means in the conveyance direction. It is characterized in that the upstream end of the means projects between the flaps located above and below when the carton is folded, and is gradually inclined in the vertical direction as it goes downstream in the conveying direction.

<Function> According to the technical means of the present invention, as the suction cup moves, the lower folding edge of the carton comes into pressure sliding contact with the inclined surface of the fixed inclined guide, thereby gradually pressing the carton in the opening direction. The carton gradually opens into a rectangular opening on the conveyance path, and then, at approximately the same time as the opened carton gradually returns to the folding direction, the folding means tilts downward while conveying the carton downstream by the conveyance mechanism. The carton is compressed and folded vertically, and at the time of folding, the upstream end of the flap folding means is inserted between the flaps that are about to overlap vertically again, so that the flaps are sorted in the vertical direction. The carton is opened again after being expanded substantially at right angles along the vertically inclined surfaces.

<Example> An example of the present invention will be described below based on the drawings.

In this embodiment, as shown in FIGS. 1 and 3 to 7, a rotary conveying mechanism 2 connects suction cups 2a, 2a, 2a to the outer end gears of three planetary gear trains meshed with the outer periphery of a fixed gear. By configuring the suction cups 2a, 2a, 2a to be moved in a substantially equilateral triangular adduction trochoid locus, the first apex of the suction cups 2a, 2a, 2a is folded flat from the magazine 1 arranged in an inclined manner. At the same time, the cartons A taken out at the second vertex are brought into pressure-sliding contact with the fixed inclined guide 3 and sucked by the suction cup 2a. This is to cancel the .

The fixed inclined guide 3 is located at the upstream end of the conveyance path 4 along the movement locus of the suction cup 2a, that is, from the first apex to the second apex of the internal rotation trochoid locus, and its inclined surface 3a is positioned downstream in the conveyance direction. The inclined surface 3a is inclined at an angle that gradually approaches and intersects the movement locus of the folded carton A and the lower folding edge _A1 as it goes toward the conveyance path 4 and the downstream side, By moving the suction cup 2a, the lower folding edge _A1 is pressed into sliding contact with the inclined surface 3a, and is gradually pressed toward the opening of the carton A.

Further, below the inclined surface 3a, a vertical surface 3b is provided.
are arranged in series to form the vertical surface 3b and the upper surface of the horizontal conveyance path 4 into an L shape, and the lower folding edge _A1 of the carton A, which is open on the upper surface of the conveyance path 4, is engaged with the vertical surface 3b. This prevents it from descending and moving upstream.

In this embodiment, one pair of fixed inclined guides 3 are provided in the left and right width direction perpendicular to the conveyance direction of the conveyance path 4,
The inclination angle of each inclined surface 3a is approximately 25 degrees.

The conveyance path 4 is a horizontal path leading from the fixed inclined guide 3 to the cartoning machine (not shown) side, and runs along the lower surface of the carton A, which is open on the upper surface, and conveys only the lower surface side of the carton A. A conveyance mechanism 4a for conveying to the downstream side in the direction is provided.

The conveyance mechanism 4a is constituted by a belt conveyor having protrusions _4a1 projecting outward at equal intervals, which contact only the lower end of the upstream side surface of the opened carton A.
In the case of the embodiment, a pair is provided inside the left and right fixed inclined guides 3, 3.

Further, on the downstream side of the fixed inclined guide 3 in the conveyance direction, a folding means 5 is disposed along the conveyance path 4 so as to be inclined downward in a direction that gradually approaches the conveyance path 4 as it goes downstream. The upper folding edge _A2 of the carton A conveyed by the mechanism 4a is aligned with the folding means 5, so that the carton A is gradually compressed in the vertical direction while being conveyed, and the folding direction that was previously folded in the magazine 1 is matched. Fold in the same direction.

In the case of this embodiment, the folding means 5 is constituted by a belt conveyor 5a having downwardly inclined protrusions _5a1 , and a pair of left and right belt conveyors constituting the conveyance mechanism 4a are arranged oppositely above each other. Complete folding is achieved by making the distance between the lower end surfaces of both belt conveyors 5a, 5a and the upper surfaces of the left and right belt conveyors of the conveyance mechanism 4a substantially the same as the thickness dimension of the carton A when folded.

Further, on the downstream side of the folding means 5, there are upper and lower flaps A ₃ and A ₄ that are continuous with the upper and lower surfaces of the folded carton A and protrude in the left-right direction, and that are continuous with the upstream side and downstream side of the carton A. Flap folding means 6 are disposed along the left and right side edges of the conveyance path 4 for respectively expanding the front and rear flaps A ₅ and A ₆ that protrude in the left and right directions.

The flap folding means 6 includes upper and lower flaps A ₃ , which protrude from the tips of the front and rear flaps A ₅ , A ₆ of the carton A.
Insert between the tips of A ₄ and these upper and lower flaps A ₃ ,
A pair of left and right guide bodies 6a, 6a that expand A ₄ in the vertical direction, and a top and bottom flap that folds in 90 degrees the top and bottom flaps A ₃ , A ₃ , A ₄ , A ₄ expanded by these guide bodies 6 a, 6a. Folding plates 6b, . . . and front and rear flap folding plates 6c, 6c for folding the front and rear flaps A ₅ , A ₅ , A ₆ , A ₆ after being expanded by 90 degrees are sequentially arranged on the downstream side.

The guide body 6a is formed in the shape of a horizontal strip parallel to the left and right side edges of the conveyance path 4, and has an upstream end 6 in the conveyance direction.
a ₁ is extended to the upstream end position of the folding means 5 and protrudes, and by utilizing the positional deviation of the upper and lower flaps A ₃ and A ₄ in the transport direction that occurs when folding the carton A, these upper and lower flaps A ₃ and A are Inserting the upstream end 6a ₁ between _{the four} tips, and forming inclined surfaces 6a ₂ and 6a ₂ that gradually slope upward and downward by about 30 degrees from the intermediate position in the conveying direction toward the downstream side, respectively. By moving the upper and lower flaps A ₃ and A ₄ to the downstream side along these upper and lower inclined surfaces 6a ₂ and 6a ₂ , they are gradually expanded in the vertical direction.

The folding plate 6b for the upper and lower flaps is attached to the guide body 6.
The inside of the inclined surfaces 6a ₂ and 6a ₂ of a, that is, the upper and lower flaps
Front and rear flaps at locations corresponding to the proximal ends of A ₃ and A ₄
A pair of upper and lower holes are provided through the gaps _6b1 for insertion of A5 _{and A6} , and on the upstream side of each, the grooves are gradually inclined upward and downward as they go downstream, and are oriented toward the _inside of the conveyance path 4. By forming folded surfaces 6b _{2 and} 6b ₂ that are inclined at the same angle, and moving the upper and lower flaps A ₃ and A ₄ to the downstream side along these upper and lower folded surfaces 6b 2 and 6b ₂ , the flap is further expanded in the vertical direction. Fold it 90 degrees.

The front and rear flap folding plates 6c are disposed inside the guide body 6a in the same way as the upper and lower flap folding plates 6b, and the front and rear flaps A ₅ and A ₆ are arranged on the upstream side thereof.
An apex angle 6c ₁ is provided opposite to the upper and lower middle position of , and the bent surface 6c gradually inclines upward and downward, respectively, toward the downstream side from the apex angle 6c ₁ and inclines toward the inside of the conveyance path 4. ₂ and 6c ₂ are formed, and by moving the front and rear flaps A ₅ and A ₆ downstream along these folding surfaces 6c ₂ and 6c ₂ , the flap is folded at 90 degrees while being expanded in the vertical direction.

Furthermore, from a position slightly upstream to a downstream side of the flap folding means 6, a reopening means 7 is provided which compresses the folded carton A in the conveying direction and opens it into a rectangular shape again.

The re-opening means 7 is disposed on the downstream side of the belt conveyor constituting the transport mechanism 4a, and is a belt conveyor _7a with a protrusion 7a1 that is synchronously interlocked with the belt conveyor 7a.
and a descending curved surface 7 at the downstream end of the belt conveyor 7a.
The discharge conveyor 7b is disposed at a falling distance from the carton _A2 and has a large number of conveyance claws _7b1 erected at equal intervals according to the width of the cartons A in the conveyance direction, and faces the descending curved surface _7a2 . The downstream edge A of the carton A is arranged in a _{downwardly sloping} manner.
Push the upstream edge A ₇ toward the downstream side to create a descending curved surface 7
While falling along A ₂ , the downstream edge A ₈ of the carton A hits the horizontally moving conveyance claw 7b ₁ to compress the carton A in the conveyance direction to form a rectangular opening, and as the conveyance claw 7b ₁ moves forward, the carton A is compressed in the conveyance direction. The other conveying claws _7b1 that gradually rise from the upstream side of the carton A, which has been reopened, sandwich both sides of the carton A and convey it to a packaging machine (not shown).

Furthermore, a carton A is placed at the lower end of the inclined plate 7c with an interval slightly longer than the vertical height dimension of the re-opened carton A between the upper surface of the discharge conveyor 7b and the upper surface of the discharge conveyor 7b.
A horizontal surface 7c ₁ is provided in series to prevent the surface from rising.

Next, the operation of such a carton assembly device will be explained.

First, the magazine 1 is moved by the rotation transport mechanism 2.
The carton A folded flat is taken out one by one by suction, and this carton A is shown in Figures 3 to 6.
It is rotated and transferred downward in a substantially equilateral triangular adduction trochoidal trajectory as shown in the figure.

By the time the carton A approaches the second apex of the internal rotation trochoid locus, the lower folded edge _A1 of the carton A comes into pressure-sliding contact with the inclined surface 3a of the fixed inclined guide 3, causing the carton to close as shown in FIG. As the carton A moves downward, the lower folding edge _A1 is gradually pressed in the opening direction of the carton A, and the carton A is opened into a rectangular shape.

Lower folding edge of carton A gradually opening
A ₁ descends along the vertical plane 3b, and the car reaches the ton A.
By the time the lower surface of the 8th
As shown in the figure, the carton A is opened into a rectangular shape, and at this time the suction of the suction cup 2a is released.

Due to its folding tendency, the square-opened carton A tries to return to the same direction as the folding direction in which it was folded in the magazine 1, and its upper folding edge A ₂
Almost at the same time as the
Carton A is conveyed downstream by driving a belt conveyor with protrusions _4a1 constituting conveyance mechanism 4a.

As a result, while the upper folding edge _A2 is made to follow the belt conveyor 5a with the downwardly inclined protrusion _5a1 constituting the folding means 5, the carton A is conveyed and gradually compressed in the vertical direction, as shown in FIG. It is folded in the same direction as the direction in which it was folded in the magazine 1 in advance.

At the time of this folding, the flap folding means 6
The upstream end 6a ₁ of the guide body 6a constituting the guide body 6a is inserted between the tips of the upper and lower flaps A ₃ and A ₄ , and the folded carton A is then conveyed downstream as shown in FIG. Upper and lower flaps A ₃ and A ₄ are the first
As shown in FIGS. 1 and 12, it gradually expands in the vertical direction along the inclined surfaces 6a ₂ and 6a ₂ .

Thereafter, the upper and lower flaps A ₃ and A ₄ are folded outward at 90 degrees by the upper and lower flap folding plates 6b and 6b as shown in FIGS. By pushing the protrusion _7a1 of 7a, the front flap _A5 located at the lower side on the downstream side in the conveyance direction is moved downward from the apex angle 6c1 of the front and rear flap folding plate _6c as shown in FIGS. 15 and 16. By moving along the folding surface _6c2 , it is gradually expanded downward and folded outward at 90 degrees.

Thereafter, when the rear flap A ₆ located at the upper side on the upstream side in the conveying direction approaches the apex angle of the front and rear flap folding plate 6c, the reopening means 7 is configured as shown in FIGS. 17 and 18. Belt conveyor 7a
The carton A is compressed in the conveying direction by the protrusion _7a1 and the conveying claw _7b1 of the discharge conveyor 7b, and the carton A is gradually opened, and at the same time, the carton A begins to descend obliquely along the downwardly curved surface _7a2 .

As a result, the rear flap _A6 moves from the apex angle _6c1 along the upward bending surface _7c2 , so that
As the carton A gradually expands upward and is folded outward at 90 degrees, the carton A opens squarely again. From then on, it is sandwiched between the conveyor claws 7b ₁ and 7b ₁ of the discharge conveyor 7b, and then transported to the packaging machine ( (not shown).

<Effects of the Invention> Since the present invention has the above configuration, it has the following advantages.

As the suction cup moves, the lower folding edge of the carton comes into pressure sliding contact with the inclined surface of the fixed inclined guide, gradually pressing the carton in the opening direction, so that the carton gradually opens and forms a rectangular opening on the conveyance path. Then, at approximately the same time that the opened carton gradually returns to the folding mode, the carton is conveyed downstream by the conveyance mechanism and placed along the downwardly inclined folding means, whereby the carton is vertically compressed and folded. At the time of folding, the upstream end of the flap folding means is inserted between the flaps that are about to overlap vertically again, so that the flaps are sorted in the vertical direction and expanded at a substantially right angle along the vertical slope. , since the carton is reopened, the carton is simply moved by the suction cup, and without interlocking with the moving body, the carton is reliably opened in a rectangular shape and conveyed horizontally, allowing for smooth folding and folding of the flaps that overlap above and below. It can be accurately sorted vertically and folded outward.

Therefore, compared to the conventional system, which requires accurate timing of the movement locus of the folding edge of the carton and the horizontal movement of the pusher of the chain conveyor, this eliminates the need for adjustment work and improves usability. Even when a carton is introduced onto the conveyance path in a short time at the apex of the trochoid locus, a sufficiently rectangular opening can be formed with a simple structure, making the entire device compact at low cost.

In addition, compared to the conventional method in which a carton is sandwiched between a pusher and a stopper by vertical movement of an inclined guide to open it in a rectangular shape, a swinging lever is abutted against the opened carton to forcefully fold it.
Even if the carton is opened into a rectangular shape or folded quickly, no excessive force is applied to the carton, the surface of the carton is less likely to be damaged, the product value is not reduced, and a large number of cartons can be folded in a short period of time, resulting in high-speed operation. In addition to being convenient, the structure can be simplified, the cost can be reduced, and the entire device can be made compact.

In addition, compared to the conventional carton, in which the conveyance mechanism transports the carton to the cartoning machine with the flaps protruding in the left and right directions perpendicular to the conveyance direction, the protruding lengths of the flaps stacked one above the other are approximately the same. In addition, the left and right width dimensions of the conveyance mechanism can be made more compact, and the cylindrical part of the reopened carton and the conveyor for filling the contents of the cartoning machine can be placed close to each other, which not only reduces the size of the entire device. The stroke of the pusher for filling the contents is also shortened, so that the filling time can be shortened, and the contents can be reliably filled without involving the flap when filling the contents.

Since the carton is brought into sliding contact with the inclined surface of the fixed inclined guide and is gradually pressed in the opening direction, it is possible to open the carton in a rectangular shape with one fixed inclined guide regardless of changes in the dimensions of the carton.

[Brief explanation of drawings]

Fig. 1 is a side view of a carton assembly device showing one embodiment of the present invention, Fig. 2 is a plan view of the same, and Figs. 3 to 6 are enlarged side views of main parts showing the operating states of the rotary conveyance mechanism step by step. Fig. 7 is a schematic diagram showing a state in which the carton gradually opens as it comes into pressure-sliding contact with a fixed inclined guide, Fig. 8 is an enlarged perspective view of the main part showing a state in which the carton is held open, and Fig. 9 is a schematic diagram showing the state in which the carton is gradually opened. Fig. 10 is an enlarged perspective view of the main part showing a state in which the carton is completely folded and the upstream end of the folding means is sandwiched between the upper and lower flaps of the carton, and Fig. 10 shows a state in which the carton is conveyed to the downstream side while being folded. Fig. 11 is an enlarged perspective view of the main part showing a state in which the upper and lower flaps are expanded by the inclined surface of the guide body, and Fig. 12 is an enlarged view taken along line 12-12 in Fig. 11. A sectional view, FIG. 13 is an enlarged perspective view of the main part showing a state in which the upper and lower flaps are expanded by the folding plates for the upper and lower flaps, and FIG. 14 is a state in which the upper and lower flaps are folded at a substantially right angle by the folding plates for the upper and lower flaps. Fig. 15 is an enlarged perspective view of the main part showing the front flap being expanded by the front and rear flap folding plates, and Fig. 16 is the main part 1 of Fig. 15.
17 is an enlarged sectional view taken along line 6-16, FIG. 17 is an enlarged perspective view of the main part showing a state in which the rear flap is expanded by the front and rear flap folding plates and the carton is opened again in a square shape, and FIG. FIG. A...Carton, _A1 ...Lower folding edge, _A3 ,
A ₄ , A ₅ , A ₆ ... Flap, 1 ... Magazine, 2
...Rotating transport mechanism, 2a... Suction cup, 3...
Fixed inclined guide, 3a... Inclined surface, 4... Conveyance path, 5... Folding means, 6... Flap folding means, 6a ₁ ... Upstream end, 7... Reopening means.

Claims (1)

[Claims] 1 A magazine that stacks and holds many flat folded cartons, and one carton from the magazine.
A rotary conveyance mechanism that moves suction cups that pick up and take out the cups one by one from a magazine to a conveyance path along a predetermined trajectory, and a conveyance mechanism that conveys square-opened cartons along a horizontal conveyance path toward a cartoning machine. , a folding means that compresses the opened carton in the vertical direction, and a re-opening means that compresses the folded carton in the transport direction and reopens it, and as the suction cup moves, the carton taken out from the magazine is folded into the suction cup. In a carton assembly device, a square opening is made on the conveyance path while the carton is being transported along a movement trajectory, and the opened carton is folded and reopened while being conveyed along the conveyance path. The sloped surface is erected so as to face downstream in the conveyance direction, and the sloped surface is inclined at an angle that gradually approaches and intersects with the movement locus of the lower folding edge of the carton as it goes toward the conveyance path and the downstream side, and the fixed slope The folding means is disposed downstream of the guide so as to be inclined downward in a direction that gradually approaches the horizontal conveyance path as it goes downstream in the conveyance direction, and from near the folding means to the upstream side of the reopening means in the conveyance direction. Then, a flap folding means is installed horizontally parallel to the conveyance path, and the upstream end of this flap folding means is made to protrude between the flaps located above and below when the carton is folded, so that it gradually moves up and down as it goes downstream in the conveyance direction. A carton assembly device characterized by an inclined structure.