CN114986984B

CN114986984B - Full-automatic paper box folding and forming mechanism with side wing thickness compensation function and method

Info

Publication number: CN114986984B
Application number: CN202210691165.2A
Authority: CN
Inventors: 杨世锡; 张玉城; 孙佳浩; 何俊; 程启超; 周辰
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2022-06-17
Filing date: 2022-06-17
Publication date: 2023-05-26
Anticipated expiration: 2042-06-17
Also published as: CN114986984A

Abstract

The invention discloses a full-automatic paper box folding and forming mechanism with a side wing thickness compensation function and a method thereof, and belongs to the technical field of packaging container preparation equipment. The mechanism comprises a supporting mechanism and a flanging mechanism; the folding mechanism comprises a first folding plate, a second folding plate and a folding platform for placing a bottom plate of the paper box; two groups of opposite sides of the folding platform are respectively externally connected with a first folding plate and a second folding plate which can be folded upwards; two sides of the first folding plate are respectively connected with a shifting fork which extends upwards; the supporting mechanism is a cuboid mould with the size matched with the paper box to be folded, and a plurality of vacuum grooves for adsorbing the paper board by vacuum effect are formed in the four side plates of the cuboid mould; thickness compensation blocks which can stretch out and draw back inside and outside are arranged on the two second side plates in the supporting mechanism, so that the lateral wings of the paper box are uniformly stressed during edge folding. The folding paper box is reasonable in structure and compact in design, can rapidly complete folding and forming work of the folding paper box with the side wings, and can greatly improve production efficiency and greatly reduce labor cost.

Description

Full-automatic paper box folding and forming mechanism with side wing thickness compensation function and method

Technical Field

The invention relates to a paper box folding and forming mechanism, in particular to a full-automatic paper box folding and forming mechanism with a side wing thickness compensation function and a full-automatic paper box folding and forming method, and belongs to the technical field of packaging container preparation equipment.

Background

The folding paper box is a green packaging container with very wide application, and is widely used for packaging medicines, foods, cigarettes and artworks, and also used for soft drinks, washing products, religious products and small hardware products. With further enhancement of environmental awareness, the folding paper box is widely applied to packages of products such as fruit juice, milk, cooked food, desserts, medicines, cosmetics and the like. In addition, the folding machine has the characteristics that the folding machine can be piled, transported and stored in a flat plate shape before folding, so that the cost of storage and transportation is greatly reduced, and rapid progress is made in recent years. The folding paper box has the characteristics of low processing cost, convenient storage and transportation, suitability for various printing modes, convenient sales and display, suitability for automatic packaging, good recycling property, environmental protection and the like, and along with the continuous improvement of the living standard of people, the demand of the folding paper box is continuously increased, and the production quality of the paper box is also required to be higher. Along with the continuous improvement of the economic development level in China, people also put forward higher requirements on commodity packages, and the folding paper box is widely applied to packages of high-grade commodities because of excellent rigidity, puncture resistance, impact resistance and display performance. However, at present, the paper box packaging production enterprises mostly adopt manual or semi-mechanical production to fold paper boxes, the production efficiency is low, and the user enterprises need a large amount of personnel to fold manually to enable the paper boxes to be formed, so that the labor cost is high. Therefore, the folding forming mechanism for manufacturing the folding paper box is developed, and has obvious cost reduction and synergy for both a packaging paper box manufacturing enterprise and a packaging user enterprise.

At present, a plurality of folding carton forming machines exist on the market, but most of cartons aimed at by the folding carton forming machines are composed of a piece of paperboard, the folding process is simple, the requirement on product quality is low, and for the cartons with side wings, the side wing parts need to be folded manually, so that the production efficiency is low. The folding paper box with the side wings in the prior art consists of a bottom plate and two side wings, and the thickness of each area of the side wings is different; in the folding process, the stress on the pasting part of the side wings and the bottom plate is required to be uniform, and the folding difficulty is high. Accordingly, there continues to be provided a new technique for enabling the automatic folding of a folding carton with side flaps to be accurately and efficiently achieved by establishing a side flap thickness compensation mechanism.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a full-automatic paper box folding and forming mechanism with a side wing thickness compensation function and a full-automatic paper box folding and forming method. The invention can realize the thickness compensation of the side wings, automatically, accurately and efficiently complete the folding and forming work of the folding paper box with the side wings, greatly improve the production efficiency and greatly reduce the labor cost.

The specific technical scheme adopted by the invention is as follows:

in a first aspect, the invention provides a full-automatic paper box folding and forming mechanism with a side wing thickness compensation function, which comprises a supporting mechanism and a flanging mechanism;

the folding mechanism comprises a first folding plate, a second folding plate and a folding platform for placing a paper box bottom plate; the horizontal cross section of the folding platform is square, and two groups of opposite sides of the folding platform are respectively externally connected with a first folding plate and a second folding plate which can be folded upwards; the two sides of the first folding plate are respectively connected with a shifting fork which extends upwards and is used for enabling two lugs of the four side wings to be folded upwards and stand up when the paper box is sent into the folding mechanism;

the supporting mechanism is positioned right above the folding platform and can move up and down; the supporting mechanism is a cuboid mould with the size matched with the paper box to be folded, and a plurality of vacuum grooves for adsorbing the paper board by vacuum effect are formed in the four side plates of the cuboid mould; two through holes are respectively formed in the second side plates on the same side of the two second folding plates in the supporting mechanism, and thickness compensation blocks capable of stretching out and drawing back inside and outside are arranged at the through holes and used for compensating the thinner areas of the two lugs of the side wings, so that the side wings of the paper box are uniformly stressed during folding.

Preferably, the first folding plate and the second folding plate are hinged to the folding platform by hinges.

Preferably, the carton is a folded package with side flaps.

Preferably, the first folding plate and the second folding plate are respectively provided with a folding assembly, and the folding assemblies comprise an air cylinder connecting block, an air cylinder, a guide rail sliding block, a folding connecting rod and a guide rail; one end of the turnover connecting rod is connected with the folding plate, and the other end of the turnover connecting rod is connected with the cylinder connecting block fixed on the guide rail sliding block; the guide rail sliding block can slide along a guide rail which is perpendicular to the folding plate, and the air cylinder connecting block is connected with a piston rod of the air cylinder; the guide rail sliding block is driven to slide along the guide rail through the telescopic action of the piston rod of the air cylinder, so that the folding plate can be folded in the vertical direction.

Preferably, the support mechanism comprises a cover plate, a support bottom plate, two first side plates and two second side plates, wherein the cover plate, the support bottom plate, the two first side plates and the two second side plates are detachably connected to form a cuboid die, and the two first side plates are respectively on the same side as the two first folding plates.

Preferably, the supporting mechanism is externally connected with vacuum equipment; the through holes and the thickness compensation blocks arranged on the second side plate are of triangular structures.

Preferably, the thickness compensation block is used for thickness compensation of the bonding positions of the four side wings and the two ears of the paper box.

Preferably, a first electromagnet, a center bracket and a second electromagnet are arranged in the inner cavity of the supporting mechanism from top to bottom at intervals; the first electromagnet is fixed at the top of the inner cavity of the supporting mechanism, the second electromagnet is fixed at the bottom of the inner cavity of the supporting mechanism, and the center support is positioned at the middle part of the inner cavity of the supporting mechanism and is respectively connected with the thickness compensation block through four hinged push-out connecting rods; the upper surface and the lower surface of the central support are respectively provided with a ferromagnetic piece, and the ferromagnetic piece can be attracted by the first electromagnet or the second electromagnet to realize up-and-down movement, so that the thickness compensation block is driven by the push-out connecting rod to realize internal and external expansion.

Preferably, the fork comprises a vertical section and an inclined section which are connected in sequence, the vertical section is fixed on the first folding plate, and the inclined section is inclined towards a direction far away from the first folding plate.

In a second aspect, the invention provides a method for folding a paper box by using the full-automatic paper box folding and forming mechanism, which comprises the following steps:

feeding the paper box to be folded into a folding mechanism, enabling the paper box bottom plate to be located on a folding platform, enabling four paper box side edges connected with the paper box bottom plate to be located on a first folding plate or a second folding plate respectively, and enabling two lugs of four side wings of the paper box to be folded upwards and stand under the action of a shifting fork; the supporting mechanism descends to press the two sides of the bottom plate of the paper box together with the folding platform, and the supporting mechanism is externally connected with vacuum equipment so that a vacuum groove formed in the side plate has adsorption force;

the second electromagnet is electrified to enable the center support to be attracted by magnetic force to move downwards; the pushing-out connecting rod moves downwards and rotates outwards, and simultaneously drives the thickness compensation block to move outwards so as to compensate the thickness of the bonding parts in the two lugs of the four side wings of the paper box; the two first folding plates are upwards folded, so that two first side edges of the paper box on the first folding plates are upwards folded and are attached to the first side plates under the action of the vacuum grooves, and two lugs of four side wings of the paper box are attached to the second side plates; then, the two second folding plates are upwards folded, so that the two second side edges of the paper box on the second folding plates are upwards folded, and the two lugs of the four side wings of the paper box are adhered to the two second side edges under the action of the second folding plates, so that the paper box folding operation is completed;

the first electromagnet is electrified to enable the center support to be attracted by magnetic force to move upwards; the pushing-out connecting rod moves upwards and rotates inwards and outwards, and meanwhile, the thickness compensation block is driven to move inwards; the supporting mechanism is lifted up to enable the folded paper box to fall off.

Compared with the prior art, the invention has the following beneficial effects:

1) The thickness compensation of the paper box side wings is realized through the crank sliding block mechanism driven by the electromagnet, so that the stress is uniform when the paper box side wings are folded; 2) After the folding forming, the thickness compensation block can be retracted, so that the paper box can be conveniently demoulded; 3) The flanging mechanism disclosed by the invention is simple and accurate in action, high in working efficiency and high in automation degree.

Drawings

FIG. 1 is an expanded view of a carton of an embodiment of the present invention;

FIG. 2 is a schematic view of a carton of an embodiment of the present invention completing a fold bond;

FIG. 3 is a schematic view of a construction of the fold formation mechanism of the carton of the present invention;

FIG. 4 is a schematic view of the hemming mechanism of FIG. 3;

FIG. 5 is a schematic view of the internal structure of the support device of FIG. 3;

reference numerals: 1-a folding platform; 2-shifting fork; 3-a first folding plate; 4-cylinder connecting blocks; 5-cylinder; 6, a guide rail slide block; 7-turning over a connecting rod; 8, a guide rail; 9-a second folding plate; 10-cover plate; 11-a first side plate; 12-a second side panel; 13-a central support; 14-a first electromagnet; 15-a second electromagnet; 16-push out link; 17-a thickness compensation block; 18-supporting the soleplate.

Detailed Description

The invention is further illustrated and described below with reference to the drawings and detailed description. The technical features of the embodiments of the invention can be combined correspondingly on the premise of no mutual conflict.

The paper box of the embodiment is a folding packing box with side wings, and as shown in fig. 1, the paper box to be folded of the embodiment is an unfolding view. The paper box comprises a paper box bottom plate, two paper box long side surfaces, two paper box short side surfaces, two paper box side wing parts, namely a paper box bottom plate, two paper box short side surfaces, a paper box side wing part and a paper box side wing part, wherein the paper box side wing parts are formed by the two paper box side surfaces, namely the paper box side wing parts, the paper box side wing parts are formed by the two paper box side surfaces, namely the paper box side wing parts are formed by the two paper box side wing parts, namely the paper box side wing parts are formed by the paper box side wing parts, namely the paper box side surfaces and the paper box side wing part, the paper box side wing part. The face (8) is a relatively thin adhesive bond in the ears of the side flaps of the carton and is required to ensure uniform stress when folded.

As shown in fig. 3, the full-automatic paper box folding and forming mechanism with the function of compensating the thickness of the side wings provided by the embodiment mainly comprises a supporting mechanism and a flanging mechanism. The supporting mechanism is arranged right above the flanging mechanism and can move up and down; when the paper box raw materials are fed, the supporting mechanism descends to press the paper board, the flanging mechanism starts to act, and the paper box is folded. The structure and connection of the support mechanism and the hemming mechanism will be described in detail.

As shown in fig. 4, the hemming mechanism mainly includes a first folding plate 3, a second folding plate 9, and a folding platform 1, wherein the folding platform 1 is used for placing a carton bottom plate, and the first folding plate 3 and the second folding plate 9 are respectively used for placing four side plates connected with the carton bottom plate. The horizontal cross section of the folding platform 1 is square, and comprises two groups of opposite sides, wherein the first group of opposite sides are respectively externally connected with a first folding plate 3 which can be upwards folded, and the second group of opposite sides are respectively externally connected with a second folding plate 9 which can be upwards folded. Two sides of the first folding plate 3 are respectively connected with a shifting fork 2 which extends upwards and is used for enabling two lugs of the four side wings to be folded upwards and raised when the paper box is fed into the folding mechanism.

In this embodiment, taking the horizontal cross section of the folding platform 1 as an example, the short side and the long side are hinged with a short side folding plate and a long side folding plate respectively by hinges, the short side folding plate and the long side folding plate are respectively provided with a folding connecting rod, the folding connecting rods are connected with an air cylinder connecting block, the air cylinder connecting block is fixed on a guide rail sliding block, the guide rail sliding block can slide along the guide rail, the guide rail is perpendicular to the folding plate, and the air cylinder piston is connected with the air cylinder connecting block. The cylinder connecting block 4 can be set to L-shaped connecting piece, and one end is connected with the folding connecting rod 7, and one section is connected with the cylinder 5 to fix on the guide rail slider 6, when the cylinder acts, the cylinder piston rod stretches out, promotes the cylinder connecting block and removes, and the guide rail slider translates along the guide rail, turns over the compound motion that the connecting rod also moves along with it and does translation and rotate, drives the short side folding plate and long side folding plate and rotates around folding platform's minor face and long limit respectively, realizes the hem operation. The shifting fork 2 comprises a vertical section and an inclined section which are sequentially connected, the vertical section is fixed on the first folding plate 3, and the inclined section is inclined towards the direction far away from the first folding plate 3, so that two lugs (namely faces (7) (8)) of four side wings can be upwards folded for 90 DEG to stand up under the limiting and blocking action of the shifting fork 2 in the process that the paper box to be folded is fed into the folding mechanism from top to bottom.

As shown in fig. 5, the supporting mechanism is a cuboid mold with a size corresponding to the paper box to be folded, and a plurality of vacuum grooves for adsorbing the paper board through vacuum effect are formed in the four side plates of the cuboid mold. Two through holes are respectively formed in the second side plates 12 on the same side as the two second folding plates 9 in the supporting mechanism, and thickness compensation blocks 17 capable of stretching and retracting inside and outside are arranged at the through holes so as to enable the lateral wings (mainly referred to as surfaces (8)) of the paper box to be stressed uniformly during folding.

In this embodiment, the support mechanism is exemplified by a rectangular parallelepiped. The supporting mechanism comprises a supporting bottom plate 18, the supporting bottom plate 18 is located right above the folding platform 1, two short side plates and two long side plates are arranged on four sides of the supporting bottom plate 18, a cover plate 10 is arranged on the tops of the short side plates and the long side plates, the cover plate 10, the supporting bottom plate 18, the short side plates and the long side plates jointly form a cuboid mould, the size of the cuboid mould is matched with that of the paper box, and the paper box is supported in the folding process. The short side plate and the long side plate are respectively provided with vacuum grooves which are uniformly distributed, and the vacuum grooves are connected with vacuum equipment to adsorb the paper board. Two triangular holes are formed in the long side plate, a thickness compensation block 17 is arranged in the holes, two pushing-out connecting rods 16 are arranged on the thickness compensation block 17, the other ends of the pushing-out connecting rods 16 are connected with a center support 13, and a first electromagnet 14 and a second electromagnet 15 are respectively arranged right above and right below the center support 13. The upper and lower surfaces of the center support 13 are respectively provided with a ferromagnetic piece, and the ferromagnetic piece can be attracted by the first electromagnet 14 or the second electromagnet 15 to realize up-and-down movement, so that the thickness compensation block 17 is driven by the push-out connecting rod 16 to realize internal and external expansion. The ferromagnetic members herein refer to objects having ferromagnetism that can be fixed on the upper and lower surfaces of the center frame 13, respectively, or the center frame 13 may be made of ferromagnetic materials. Specifically, when the first electromagnet 14 is energized, the center support 13 is attracted by magnetic force to move upwards, so as to drive the push-out connecting rod 16 to move upwards and rotate inwards, and the push-out connecting rod 16 drives the thickness compensation block 17 to move inwards. When the second electromagnet 15 is electrified, the center support 13 is attracted by magnetic force to move downwards, the push-out connecting rod 16 moves downwards and rotates outwards, and the push-out connecting rod 16 drives the thickness compensation block 17 to move outwards.

The paper box folding method utilizing the full-automatic paper box folding and forming mechanism comprises the following steps of:

the paper box to be folded is sent into a flanging mechanism, so that a paper box bottom plate (namely a face (4)) is overlapped with the folding platform 1, four paper box side edges (namely faces (3) (5) (6)) connected with the paper box bottom plate are respectively positioned on the first folding plate 3 or the second folding plate 9, and two lugs (namely faces (7) (8)) of four side wings of the paper box to be folded are upwards folded for 90 degrees to stand under the action of the shifting fork 2. The supporting mechanism descends and presses the upper surface of the bottom plate of the paper box, and the supporting mechanism is externally connected with vacuum equipment so that a vacuum groove formed in the side plate has adsorption force on the paper plate.

The second electromagnet 15 positioned below is electrified to make the center bracket 13 move downwards under the attraction of magnetic force. The push-out link 16 moves downwardly and rotates outwardly, which simultaneously drives the thickness compensation block 17 outwardly to compensate for the thickness of the adhesive (i.e., the face (8)) in the two ears of the four side flaps of the carton. The cylinder 5 acts to push the cylinder connecting block 4 to translate along the guide rail, drives the folding connecting rod 7 to translate and rotate, and enables the two first folding plates 3 to fold upwards, so that the two first side edges (namely the faces (6)) of the paper box on the first folding plates 3 are driven to fold upwards and are attached to the first side plate 11 under the action of the vacuum groove, and the two lugs (namely the faces (7) (8)) of the four side wings of the paper box are attached to the second side plate 12. Then the cylinder 5 acts to push the cylinder connecting block 4 to translate along the guide rail, and drives the folding connecting rod 7 to translate and rotate, so that the two second folding plates 9 are folded upwards, and the two second sides (namely the faces (3) and (5)) of the paper box on the second folding plates 9 are folded upwards, and at the moment, the faces (3) and (5) are attached to the outer sides of the faces (7) and (8). The two ears of the four side flaps of the carton, i.e., panels (8), are bonded to the two second side edges, i.e., panels (3) (5), by the second folding plate 9 to complete the carton folding operation.

The first electromagnet 14 is energized to make the center support 13 move upwards under the attraction of magnetic force. The push-out link 16 moves upward and rotates inward and outward, and at the same time, drives the thickness compensation block 17 to move inward. The supporting mechanism is lifted up to enable the folded paper box to fall off. The folded carton of this embodiment is shown in figure 2.

The folding paper box is reasonable in structure and compact in design, can rapidly complete folding and forming work of the folding paper box with the side wings, and can greatly improve production efficiency and greatly reduce labor cost.

The above embodiment is only a preferred embodiment of the present invention, but it is not intended to limit the present invention. Various changes and modifications may be made by one of ordinary skill in the pertinent art without departing from the spirit and scope of the present invention. Therefore, all the technical schemes obtained by adopting the equivalent substitution or equivalent transformation are within the protection scope of the invention.

Claims

1. A paper box folding method utilizing a full-automatic paper box folding and forming mechanism with a side wing thickness compensation function is characterized in that the full-automatic paper box folding and forming mechanism with the side wing thickness compensation function comprises a supporting mechanism and a flanging mechanism; the folding mechanism comprises a first folding plate (3), a second folding plate (9) and a folding platform (1) for placing a bottom plate of the paper box; the horizontal cross section of the folding platform (1) is square, and two groups of opposite sides of the folding platform are respectively externally connected with a first folding plate (3) and a second folding plate (9) which can be folded upwards; two sides of the first folding plate (3) are respectively connected with a shifting fork (2) which extends upwards and is used for enabling two lugs of the side wings to be folded upwards and raised when the paper box is sent into the folding mechanism; the supporting mechanism is positioned right above the folding platform (1) and can move up and down; the supporting mechanism is a cuboid mould with the size matched with the paper box to be folded, and a plurality of vacuum grooves for adsorbing the paper board by vacuum effect are formed in the four side plates of the cuboid mould; two through holes are respectively formed in a second side plate (12) on the same side as the two second folding plates (9) in the supporting mechanism, and thickness compensation blocks (17) which can stretch out and draw back inwards and outwards are arranged at the through holes and used for compensating the side wing lug areas, so that the side wings of the paper box are uniformly stressed during folding; a first electromagnet (14), a center bracket (13) and a second electromagnet (15) are arranged in the inner cavity of the supporting mechanism from top to bottom at intervals; the first electromagnet (14) is fixed at the top of the inner cavity of the supporting mechanism, the second electromagnet (15) is fixed at the bottom of the inner cavity of the supporting mechanism, and the center bracket (13) is positioned in the middle of the inner cavity of the supporting mechanism and is respectively connected with the thickness compensation block (17) through four hinged push-out connecting rods (16); the upper surface and the lower surface of the central bracket (13) are respectively provided with a ferromagnetic piece which can be attracted by the first electromagnet (14) or the second electromagnet (15) to realize up-and-down movement, and further the thickness compensation block (17) is driven by the push-out connecting rod (16) to realize internal and external expansion;

the paper box folding method specifically comprises the following steps:

feeding the paper box to be folded into a flanging mechanism, enabling a paper box bottom plate to be positioned on a folding platform (1), enabling four paper box side edges connected with the paper box bottom plate to be respectively positioned on a first folding plate (3) or a second folding plate (9), and enabling two lugs of a side wing of the paper box to be folded upwards and vertically under the action of a shifting fork (2); the supporting mechanism descends to press two sides of the bottom plate of the paper box together with the folding platform (1), and the supporting mechanism is externally connected with vacuum equipment so that a vacuum groove formed on the side plate has adsorption force;

the second electromagnet (15) is electrified to enable the center bracket (13) to be attracted by magnetic force to move downwards; the pushing-out connecting rod (16) moves downwards and rotates outwards, and simultaneously drives the thickness compensation block (17) to move outwards so as to compensate the thickness of the bonding parts in the two lugs of the four side wings of the paper box; the two first folding plates (3) are upwards folded, so that two first side edges of the paper box positioned on the first folding plates (3) are upwards folded and are attached to the first side plate (11) under the action of the vacuum groove, and two lugs of four side wings of the paper box are attached to the second side plate (12); then, the two second folding plates (9) are upwards folded, so that the two second side edges of the paper box on the second folding plates (9) are upwards folded, and the two sides of the four side wings of the paper box are adhered to the two second side edges under the action of the second folding plates (9), so that the paper box folding operation is completed;

the first electromagnet (14) is electrified to enable the center support (13) to be attracted by magnetic force to move upwards; the pushing-out connecting rod (16) moves upwards and rotates inwards and outwards, and meanwhile drives the thickness compensation block (17) to move inwards; the supporting mechanism is lifted up to enable the folded paper box to fall off.

2. A method of folding a carton as claimed in claim 1, characterized in that the first folding plate (3) and the second folding plate (9) are each hinged to the folding platform (1) by means of a hinge.

3. The method of folding a carton as claimed in claim 1 wherein the carton is a folded box with side flaps.

4. The method for folding the paper box according to claim 1, wherein a folding assembly is arranged on each of the first folding plate (3) and the second folding plate (9), and comprises a cylinder connecting block (4), a cylinder (5), a guide rail sliding block (6), a folding connecting rod (7) and a guide rail (8); one end of the turnover connecting rod (7) is connected with the folding plate, and the other end of the turnover connecting rod is connected with the cylinder connecting block (4) fixed on the guide rail sliding block (6); the guide rail sliding block (6) can slide along a guide rail (8) which is perpendicular to the folding plate, and the air cylinder connecting block (4) is connected with a piston rod of the air cylinder (5); the guide rail sliding block (6) is driven to slide along the guide rail (8) through the telescopic action of the piston rod of the air cylinder (5), so that the folding plate can be folded in the vertical direction.

5. A method of folding a carton as claimed in claim 1, characterized in that the support means comprise a cover plate (10), a support base plate (18), two first side plates (11) and two second side plates (12) which are detachably connected to form a cuboid mould, the two first side plates (11) being on the same side as the two first folding plates (3), respectively.

6. The method of folding a carton as in claim 1 wherein the support mechanism circumscribes a vacuum device; the through holes and the thickness compensation blocks (17) arranged on the second side plate (12) are of triangular structures.

7. A method of folding a carton as claimed in claim 1, characterised in that the thickness compensation block (17) is provided for thickness compensation of the bond in the ears of the side flaps of the carton.

8. A method of folding a carton as claimed in claim 1, wherein the fork (2) comprises a vertical section and a sloping section connected in sequence, the vertical section being secured to the first folding plate (3), the sloping section being sloping away from the first folding plate (3).