JP7628271B2 - Lid forming device - Google Patents

Description

The present invention relates to a lid forming device, and in particular to a lid forming device for cardboard boxes.

Conventionally, a known device for forming a lid for a cardboard box is one that forms a slit or the like in the flap that is to be folded first among a group of flaps provided around the edge of the opening of the cardboard box, and then inserts the tip of the flap that is to be folded later into the slit. For example, in the automatic box-sealing device described in Patent Document 1 (JP Patent Publication 58-3881), a long hole is formed in the first flap that is to be folded first, and the second flap that is to be folded later is folded, and then the tip of the second flap is aligned with the top surface of the first flap and the folded portion is pushed in, so that the tip of the second flap is inserted into the long hole.

However, some cardboard boxes are reused, and the flap itself may not maintain its original hardness or strength. If the second flap in this state is folded and the folded part is pushed in, the second flap may buckle at its weak tip, and the tip of the second flap may not be inserted into the long hole of the first flap.

The objective of the present invention is to provide a lid forming device that is configured to facilitate the insertion of a part of a flap into a slit in a flap of a cardboard box.

The lid forming device according to the first aspect of the present invention is a lid forming device that forms a lid for a cardboard box by a first flap having a slit formed therein and a second flap that is folded in a mountain shape and then stretched out, among a group of flaps that are provided in a cantilever shape on the edge of an opening of a cardboard box, and includes a first folding mechanism and a second folding mechanism. The first folding mechanism folds the first flap in a direction to close the opening. The second folding mechanism performs a first operation of folding the second flap in a mountain shape, inserting the second flap folded in a mountain shape into the slit to a position that is a first dimension away from the tip of the second flap, and then returning the second flap to a state where it is inserted into the slit to a position that is a second dimension away from the tip, which is shorter than the first dimension, and performs a second operation of further inserting the tip of the second flap inserted into the slit toward the back side of the slit during the process of stretching the second flap after the first operation. The second folding mechanism includes a first holding unit and a second holding unit. The first holding portion suction-holds a first surface of the second flap closer to the free end than a predetermined folding line, and the second holding portion suction-holds a second surface of the second flap closer to the fixed end than the folding line.

In this lid forming device, the folded portion of the second flap is stretched so that the tip of the second flap enters the slit of the first flap, so no extra load is placed on the second flap and the second flap does not buckle, making it easier for the tip to be inserted into the slit.

Furthermore, with this lid forming device, even if the slit of the first flap becomes distorted due to the reuse of cardboard boxes, the tip of the second flap extends from the state in which it is inserted into the slit, thereby ensuring that the tip is inserted further in from the slit.

Furthermore, with this lid forming device, even when the filling rate of the bags in the cardboard box is high, the second flap can be inserted deeply into the slit, thereby ensuring space for the second flap to slide in.

The lid forming device according to a second aspect of the present invention is the lid forming device according to the first aspect, in which the second folding mechanism holds the second flap with the first holding part and the second holding part, and folds the second flap by moving the first holding part and the second holding part individually until the relative angle between the first surface and the second surface of the second flap is reduced to a predetermined angle.

In this lid forming device, the first and second sides of the second flap are moved separately, allowing both sides to be equally loaded, reducing folding defects.

The lid forming device according to the third aspect of the present invention is the lid forming device according to the first or second aspect, in which the second folding mechanism moves the first and second holding parts individually in a direction in which the relative angle between the first and second surfaces of the second flap increases while aligning the tip of the folded second flap with the upper surface of the first flap, and guides the free end of the second flap into the slit in the first flap.

In this lid forming device, the tip of the second flap is aligned with the top surface of the first flap while being stretched in a direction that widens the relative angle between the first and second surfaces of the second flap, so that no extra load is placed on the second flap and the tip of the second flap is smoothly inserted into the slit of the first flap without being deformed.

The lid forming device according to a fourth aspect of the present invention is a lid forming device according to any one of the first to third aspects, in which the first holding part has a first suction device that adsorbs the first surface. Also, the second holding part has a second suction device that adsorbs the second surface.

This lid forming device uses an adsorption method, which reduces stress concentration on the flap compared to mechanical gripping, and can suppress deformation, etc.

The lid forming device according to the fifth aspect of the present invention is the lid forming device according to the fourth aspect, in which the first holding part has a first cover that surrounds a part of the periphery of the first suction device. Also, the second holding part has a second cover that surrounds a part of the periphery of the second suction device.

In this lid forming device, when folding the second flap, the first suction device only adheres to the first surface and the second suction device only adheres to the second surface, and the force transmission to the first surface during folding is handled by the first cover and the force transmission to the second surface is handled by the second cover, so damage to the first and second suction devices due to friction is suppressed.

The lid forming device according to the sixth aspect of the present invention is the lid forming device according to the fourth aspect, in which the first suction device selectively switches the timing for opening the first surface after suctioning the first surface. Also, the second suction device selectively switches the timing for opening the second surface after suctioning the second surface.

A seventh aspect of the present invention is the lid forming apparatus according to the first aspect, wherein the second folding mechanism further includes a drive unit. The drive unit drives the first holding unit and the second holding unit until the relative angle between the first surface and the second surface of the second flap becomes a predetermined angle.

With this lid forming device, when folding the second flap into a mountain shape, the second flap can be folded at an angle suitable for inserting the second flap into the slit.

A lid forming apparatus according to an eighth aspect of the present invention is the lid forming apparatus according to the seventh aspect, wherein the predetermined angle is set within the range of 90 to 120 degrees.

A lid forming device according to a ninth aspect of the present invention is a lid forming device that forms a lid for a cardboard box by a first flap having a slit formed therein and a second flap that is folded in a mountain shape and then stretched out of a group of flaps that are provided in a cantilever shape on the edge of an opening of a cardboard box, and includes a first folding mechanism, a second folding mechanism, and a control unit that controls the second folding mechanism. The first folding mechanism folds the first flap in a direction to close the opening. The second folding mechanism folds the second flap in a mountain shape and stretches it, and inserts a part of the second flap into the slit of the first flap in the process of stretching the second flap. The second folding mechanism includes a first holding unit, a second holding unit, a first driving unit, a second driving unit, a third driving unit, and a measuring unit. The first holding unit suction-holds a first surface closer to the free end than a folding line that is preset on the second flap. The second holding unit suction-holds a second surface closer to the fixed end than the folding line. The first drive unit rotates the second flap around the fixed end of the second surface. The second drive unit holds and releases the first and second surfaces of the second flap using the first and second holding units. The third drive unit drives the first and second holding units until the relative angle between the first and second surfaces of the second flap becomes a predetermined angle. The measurement unit measures at least the operation time of the third drive unit and outputs it to the control unit. The control unit adjusts the operation of the first drive unit and/or the operation of the second drive unit based on the operation time of the third drive unit.

In this lid forming device, even when the operation of the third drive unit is unstable and the time it takes for the first and second surfaces of the second flap to form a predetermined angle is not stable, the first drive unit and the second drive unit perform operations appropriate to the operation time of the third drive unit, thereby stabilizing the series of operations of the second folding mechanism.

A lid forming apparatus according to a tenth aspect of the present invention is the lid forming apparatus according to the ninth aspect, wherein the first drive unit is a servo motor and the third drive unit is an air cylinder.

A lid forming device according to an eleventh aspect of the present invention is a lid forming device that forms a lid for a cardboard box by a first flap having a slit formed therein and a second flap that is folded in a mountain shape and then stretched out, among a group of flaps provided in a cantilever shape on the edge of an opening of the cardboard box, and includes a first folding mechanism, a second folding mechanism, a control unit, and a detection unit. The first folding mechanism folds the first flap in a direction to close the opening. The second folding mechanism folds the second flap in a mountain shape and stretches it, and inserts a part of the second flap into the slit of the first flap in the process of stretching the second flap. The second folding mechanism includes a first holding unit and a second holding unit. The first holding unit sucks and holds a first surface of the second flap closer to the free end than a folding line that is preset on the second flap. The second holding unit sucks and holds a second surface of the second flap closer to the fixed end than the folding line. The control unit controls the second folding mechanism. The detection unit detects a height position of the second flap folded by the second folding mechanism from a predetermined reference plane and outputs the height position to the control unit. When the control unit determines that the height position is not within the predetermined range, it causes the second folding mechanism to fold the second flap again.

This lid forming device automatically retries if a folding error occurs, so there is no need for the operator to stop the device, and a decrease in the device's operating rate can be prevented.

In the lid forming device according to the present invention, the folded portion of the second flap is stretched so that the tip of the second flap enters the slit of the first flap, so that no extra load is placed on the second flap and the second flap does not buckle, making it easier for the tip to be inserted into the slit.

1 is a block diagram of a boxing system equipped with a lid forming device according to a first embodiment of the present invention. FIG. FIG. 1 is a perspective view showing the configuration of a boxing system. FIG. 2 is a perspective view showing the flow of cardboard boxes and products in the boxing system. FIG. 2 is a perspective view of a cardboard box before the top flap is folded in. 3B is a perspective view showing the process of folding the top flap in FIG. 3A in three stages. FIG. FIG. 11 is a perspective view of the first surface holding portion and the second surface holding portion as viewed from the rear side. FIG. 13 is a side view of the second large flap folding mechanism when the first surface holding portion and the second surface holding portion adsorb the second large flap before folding. FIG. 13 is a side view of the second large flap folding mechanism when the first surface holding portion and the second surface holding portion adsorb the second large flap and start folding it. FIG. A side view of the second large flap folding mechanism when the first surface holding portion and the second surface holding portion fold the second large flap into a mountain shape. 13 is a perspective view of the second large flap folding mechanism when the first surface holding portion and the second surface holding portion extend the second large flap. FIG. FIG. 2 is a perspective view of a hook-shaped member operated by a rack and pinion mechanism. 11 is a table showing the relationship between the length of a first surface, the length of a second surface, and a predetermined angle. FIG. 4 is a block diagram showing electrical connections between the controller, the first suction cup, the second suction cup, the piston of the air cylinder for the crank, and the drive motor. 13 is a flowchart of the folding operation of the second major flap. Schematic diagram showing normal insertion operation of the second major flap. 13 is a schematic diagram showing the insertion operation of the second major flap when the filling rate of bags (products) in the cardboard box is high. FIG. 13A and 13B are schematic diagrams showing the insertion operation of the second large flap in the third embodiment. 13 is a schematic diagram showing a series of operations of the second major flap folding mechanism when the insertion operation of the second major flap is not completed normally. FIG. 13 is a schematic side view of a second large flap folding mechanism in the fourth embodiment.

The following describes an embodiment of the present invention with reference to the drawings. Note that the following embodiment is a specific example of the present invention and does not limit the technical scope of the present invention.

First Embodiment
(1) Configuration of the Packing System 1 Fig. 1 is a block diagram of a packing system 1 equipped with a cardboard box assembly device according to a first embodiment of the present invention. Fig. 2A is a perspective view showing the configuration of the packing system 1, and Fig. 2B is a perspective view showing the flow of cardboard boxes B and products G in the packing system 1.

In Figures 1 and 2A, the boxing system 1 packs a certain number of bagged products (products G), such as snack foods, into a cardboard box B in an aligned and multi-layered manner.

As shown in Figures 1 and 2A, the packing system 1 has a cardboard handling area DHA and a product handling area GHA that are connected in a state where they can be separated and independent of each other. The cardboard handling area DHA includes two processes, a box making process P1 and a packing process P3. The product handling area GHA includes a product alignment process P2.

In other words, in the boxing system 1, the cardboard handling area DHA and the product handling area GHA are connected, linking three processes: the box making process P1, the product alignment process P2, and the boxing process P3.

The box making process P1 is a process in which sheet-like cardboard box material Z is assembled into a cardboard box B and transported to the packing position, and is composed of a box material storage section 11, a box making section 12, a first position change section 13, and a box lower transport section 14.

The product alignment process P2 is a process in which products G supplied from an upstream process are brought to a predetermined position, a certain number of products G are aligned so that adjacent products partially overlap each other, and then transported to the boxing position. It is composed of a product entrance section 21, a product alignment section 22, and a product insertion section 23.

The packing process P3 is a process in which a certain number of products G that have been aligned in the product alignment process P2 are packed into a cardboard box B transported from the box making process P1, the box is closed, and the box is transported to the box discharge position. The packing process P3 is composed of a product receiving section 31, a second position change section 32, and a box sealing section 33.

The packing system 1 packs product G in a cardboard box B in multiple layers, and the product G is in an "upright position" inside the cardboard box B. In other words, when the opening of the cardboard box B is facing up, the front and back surfaces of the product G face to the sides, the top and bottom ends of the product G face up and down, and the left and right sides face to the sides.

As shown in Figures 2A and 2B, the cardboard box handling area DHA has a two-story structure, with the box-making process P1 and the boxing process P3 supported by a common frame 10, with the second floor being the box-making process P1 and the first floor being the boxing process P3.

To achieve this two-story structure, the conveying direction of the cardboard box B from the assembly of the cardboard box B in the box making section 12 to the box lower conveying section 14 is opposite to the conveying direction of the cardboard box B until the opening of the cardboard box B filled with the product G is sealed by the box sealing section 33.

(2) Box making process P1
As shown in FIG. 2B, the box making process P1 is composed of a box material storage section 11 that introduces cardboard box material Z into the packing system 1, a box making section 12 that assembles a cardboard box B, a first position change section 13 that rotates the cardboard box B 90 degrees around a horizontal axis perpendicular to the conveying direction, and a box downward conveying section 14 that conveys the cardboard box B in the first position downward.

(2-1) Box material storage section 11
In the box material storage section 11, as shown in FIG. 2B, the foremost cardboard box materials Z among those stacked at the supply position are clamped one by one and sent upward, and the sent cardboard box materials Z are rotated 90° around the vertical axis to expand them into a cylindrical shape.

The cardboard box material Z is placed at the supply position by a worker. The cardboard box material Z is folded with the flaps Zf open, and stacked horizontally with the flaps Zf positioned vertically. For ease of explanation, the flap Zf on the top side is referred to as the top flap Zfa, and the flap Zf on the bottom side is referred to as the bottom flap Zfb.

The cardboard box material Z is sent upward by the lifting mechanism 111, and when all the cardboard box material Z at the supply position has been removed, a detection signal from a detection sensor (not shown) is sent to the controller 40 (see Figure 1).

In addition, rotation of the cardboard box material Z around the vertical axis is achieved by the suction rotation mechanism 112 using suction cups to suction and hold the side of the cardboard box material Z, and rotating the suction rotation mechanism 112 90° around the vertical axis.

(2-2) Box making section 12
The box making section 12 transports the cylindrically expanded cardboard box material Z horizontally while folding the bottom flaps Zfb of the cardboard box material Z to form the bottom, and assembles the cardboard box B with the top flaps Zfa open.

(2-3) First posture transformation unit 13
The first position changing unit 13 rotates the cardboard box B by 90° in the conveying direction. More specifically, the first position changing unit 13 rotates the cardboard box B by 90° around a horizontal axis perpendicular to the conveying direction, changing the position of the cardboard box B so that the opening of the cardboard box B and the top flap Zfa are on the same vertical plane (hereinafter referred to as the first position). When the cardboard box B is in the first position, the opening faces the product handling area GHA.

(2-4) Box lower conveying section 14
The box lower transport section 14 transports the cardboard box B in the first position downward. That is, the cardboard box B is moved downward while the opening of the cardboard box B faces the product handling area GHA.

(3) Product alignment process P2
A weighing device, a bag making and packaging machine, etc. (not shown) are disposed upstream of the product alignment process P2 in the flow of products G in the packing system 1. Then, in the packing system 1, only products G that have passed the weight, sealability, foreign matter contamination inspection, etc. in the upstream processes are supplied to the product alignment process P2.

The product alignment process P2 is composed of a product carry-in section 21 that receives the products G and transports them to a predetermined position, a product alignment section 22 that aligns the products G supplied from the product carry-in section 21, and a product insertion section 23 that accumulates and pushes out the aligned products G.

(3-1) Product carrying-in section 21
The product carry-in section 21 has a product introduction conveyor 211 and a carry-in conveyor 212. The product introduction conveyor 211 receives products G that have passed inspection downstream of processes in which inspections for weight, sealability, and foreign matter contamination are performed, and guides the products G to the carry-in conveyor 212.

The carry-in conveyor 212 transports the products G transported from the product introduction conveyor 211 to the product alignment section 22.

(3-2) Product sorting unit 22
The product alignment section 22 has a first alignment conveyor 221, a second alignment conveyor 222, and a third alignment conveyor 223. The product alignment section 22 transports the products G to a predetermined position while performing an accumulating operation on the products G, and is particularly suitable for accumulating bag-shaped packages, so that it can also be used independently as a package accumulating device.

(3-3) Product Insertion Unit 23
The product insertion unit 23 sandwiches the front and rear ends of a group of products G aligned in a row on the third alignment conveyor 223 and inserts the entire group of products G into the cardboard box B. As shown in Fig. 2B, the product insertion unit 23 has a standing conveyor 231, a push-up plate 233, and an insertion plate 235 to sandwich the aligned group of products G.

(4) Packing process P3
The packing process P3 includes a product receiving section 31 that receives product G into a cardboard box B, a second position changing section 32 that changes the position of the cardboard box so that the opening faces upward, and a sealing section 33 that closes the opening of the cardboard box B while transporting the cardboard box B after the product G has been packed into the cardboard box B.

(4-1) Product receiving section 31
The product receiving section 31 maintains the cardboard box B in the first position and waits with the opening of the cardboard box B facing the insertion plate 235 of the product insertion section 23. The N products G that have become upright in the product insertion section 23 are pushed toward the opening surface of the cardboard box B by the insertion plate 235, and the product receiving section 31 waits in that position until the N products G are completely inserted into the cardboard box B from the opening toward the bottom.

When the first layer of N products G is inserted into the cardboard box B, it descends a predetermined distance. Then, in order to receive the second layer of N products G, the opening of the cardboard box B in the space above the first layer is placed facing the insertion plate 235 and waits.

By repeating the above operations, N products G in the i-th layer are inserted into cardboard box B, completing the acceptance of the products into cardboard box B.

(4-2) Second posture transformation unit 32
As shown in FIG. 2B, the second position changing section 32 has a position changing mechanism 321 that changes the position of the cardboard box B packed with products G to a position in which the opening faces upward.

The position change mechanism 321 rotates cardboard box B so that the opening, which was previously vertical, becomes horizontal, i.e., the opening faces upward. The position change mechanism 321 holds cardboard box B with an L-shaped member with suction cups that simultaneously suctions the sides and bottom of cardboard box B, and cardboard box B rotates as the L-shaped member rotates 90 degrees.

(4-3) Sealing section 33
As shown in FIG. 2B, the box sealing section 33 has a discharge conveyor 330 that transports the cardboard box B, and a lid forming device 340 that closes a flap that surrounds the opening of the cardboard box B to form a lid.

The lid forming device 340 is described in detail below.

(5) Lid forming device 340
Here, the operation of folding the top flap Zfa of the cardboard box B will be mainly described.

(5-1) Top flap Zfa of cardboard box B
First, before describing the operation, we will describe the cardboard box B handled by the boxing system 1. Fig. 3A is a perspective view of the cardboard box B before folding in the top flap Zfa. Fig. 3B is a perspective view showing three stages of the process of folding in the top flap Zfa in Fig. 3A.

In Figures 3A and 3B, the top flap Zfa includes a pair of large flaps facing each other, a first large flap Zfa1 and a second large flap Zfa2, and a pair of small flaps facing each other, a first small flap Zfa3 and a second small flap Zfa4.

The second large flap Zfa2 has a fold line BL provided in advance at the portion that will become the peak when folded into a mountain shape. The surface of the second large flap Zfa2 closer to the free end than the fold line BL is called the first surface F1, and the surface closer to the fixed end than the fold line BL is called the second surface F2.

The first small flap Zfa3 and the second small flap Zfa4 have slits formed into which the second large flap Zfa2 is inserted, with the first small flap Zfa3 side being slit Slt3 and the second small flap Zfa4 side being slit Slt4.

The slits Slt3 and Slt4 are L-shaped, with the first slit portion facing the free end of the flap and parallel to the free end, and the second slit portion facing the side end on the second large flap Zfa2 side and parallel to the side end.

Figure 3B shows the folding order of the top flaps Zfa, where the first large flap Zfa1 is folded in first, then the first small flap Zfa3 and the second small flap Zfa4 are folded in, and finally the second large flap Zfa2 is folded in.

When folding the second large flap Zfa2, it is folded in a mountain shape so that the folding line BL is at the top, and the tip of the second large flap Zfa2 is inserted into the second slit portion of the slits Slt3 and Slt4, and then extended, so that the second large flap Zfa2 slides from the slits Slt3 and Slt4 onto the underside of the first large flap Zfa1, completing the lid. This causes the four top flaps Zfa to interfere with each other and lock into place.

The lid forming device 340 automatically folds the top flap Zfa. The folding operation of the top flap Zfa is explained below.

(5-2) Configuration of the lid forming device 340 Fig. 4 is a perspective view of the main parts of the lid forming device 340. In Fig. 4, the lid forming device 340 includes a first large flap folding mechanism 71, a first small flap folding mechanism 72, a second small flap folding mechanism 73, and a second large flap folding mechanism 74.

The arrangement of each mechanism is such that, facing the transport direction of the cardboard box B, the first large flap folding mechanism 71 is disposed on the left side of the discharge conveyor 330, and the second large flap folding mechanism 74 is disposed on the right side of the discharge conveyor 330. In addition, the first small flap folding mechanism 72 is disposed upstream of the transport direction of the cardboard box B, and the second small flap folding mechanism 73 is disposed downstream of the transport direction of the cardboard box B.

The following explains the order in which they work.

(5-2-1) First large flap folding mechanism 71
The first large flap folding mechanism 71 is a mechanism that folds the first large flap Zfa1, and includes a first folding plate 711, a first connecting member 713, and a first air cylinder 715.

(5-2-1-1) First folding plate 711
The first folding plate 711 is a sheet metal member having a pressing surface 711a which is a rectangular flat surface. The first folding plate 711 is a plate for folding the first large flap Zfa1.

(5-2-1-2) First connecting member 713 and first air cylinder 715
The first connecting member 713 is a member that transmits the piston displacement of the first air cylinder 715 to the first folding plate 711.

One end of the first connecting member 713 is connected to one end of the first folding plate 711. The first connecting member 713 has a rotating shaft 713a. The rotating shaft 713a is provided near the connection with the first folding plate 711.

(5-2-1-3) Operation The other end of the first connecting member 713 is connected to the tip of the piston 715a of the first air cylinder 715. When the piston 715a reciprocates, the first connecting member 713 rotates around the rotation shaft 713a, and the first folding plate 711 swings accordingly.

The first folding plate 711 shown in FIG. 4 is in a standby position before folding the first large flap Zfa1. When the first air cylinder 715 retracts the piston 715a, the first connecting member 713 rotates together with the first folding plate 711 in the direction of the arrow D1, folding the first large flap Zfa1.

(5-2-2) First small flap folding mechanism 72
The first small flap folding mechanism 72 includes a second folding plate 721 , a second connecting member 723 , and a second air cylinder 725 .

(5-2-2-1) Second folding plate 721
The second folding plate 721 is a sheet metal member having a 1/4 arc 721a. A connection portion with the second connecting member 723 is provided at a position a predetermined distance away from the 1/4 arc 721a. The second folding plate 721 is a plate for folding the first small flap Zfa3.

(5-2-2-2) Second connecting member 723 and second air cylinder 725
The second connecting member 723 is a member that transmits the piston displacement of the second air cylinder 725 to the second folding plate 721 .

One end of the second connecting member 723 is connected to a connection portion provided on one end side of the second folding plate 721. The second connecting member 723 has a rotating shaft 723a. The rotating shaft 723a is provided near the center of the second connecting member 723.

(5-2-2-3) Operation The other end of the second connecting member 723 is connected to the tip of the piston 725a of the second air cylinder 725. As the piston 725a reciprocates, the second connecting member 723 rotates about the rotation shaft 723a, and the second folding plate 721 swings accordingly.

Before the folding operation, the second folding plate 721 waits with its tip facing horizontally. The second folding plate 721 shown in FIG. 4 rotates in the direction of arrow D2 from the waiting position, and the 1/4 arc 721a is drawn at the position where the first small flap Zfa3 is folded.

(5-2-3) Second small flap folding mechanism 73
The second small flap folding mechanism 73 includes a third folding plate 731 , a third connecting member 733 , and a third air cylinder 735 .

(5-2-3-1) Third folding plate 731
The third folding plate 731 is a band-shaped sheet metal member for folding the second small flap Zfa4.

(5-2-3-2) Third connecting member 733 and third air cylinder 735
The third connecting member 733 is a member that transmits the piston displacement of the third air cylinder 735. The third connecting member 733 is a plate-shaped sheet metal member, and one end surface of the third connecting member 733 is welded to the back surface of the third folding plate 731. Therefore, the main plane of the third connecting member 733 and the main plane of the third folding plate 731 are perpendicular to each other. Note that the back surface of the third folding plate 731 is the surface opposite to the surface that abuts against the second small flap Zfa4.

The third connecting member 733 has a rotating shaft 733a. The rotating shaft 733a is provided at the end of the third connecting member 733. A connecting member 733b for connecting the piston 735a of the third air cylinder 735 is connected near the rotating shaft 733a.

(5-2-3-3) Operation When the piston 735a reciprocates, the third connecting member 733 rotates about the rotation shaft 733a, and the third folding plate 731 swings accordingly.

The third folding plate 731 shown in FIG. 4 is in a standby position before folding the second small flap Zfa4. When the third air cylinder 735 pushes out the piston 735a, the third connecting member 733 rotates together with the third folding plate 731 in the direction of the arrow D3, folding the second small flap Zfa4.

(5-2-4) Second large flap folding mechanism 74
Fig. 5 is a perspective view of the second large flap folding mechanism 74. In Fig. 5, the second large flap folding mechanism 74 is a mechanism for folding the second large flap Zfa2, and includes a first surface holding part 741, a second surface holding part 742, a parallel crank 743, an air cylinder 744 for the crank (see Fig. 6), and a drive motor 745.

(5-2-4-1) First surface holding part 741
The first surface holding portion 741 holds the first surface F1 (see FIG. 3A) of the second large flap Zfa2. As shown in FIG. 3A, the first surface F1 is a surface of the second large flap Zfa2 closer to the free end than the folding line BL.

The first surface holder 741 includes a first suction cup 741a and a first cover 741b. The first suction cup 741a has a circular suction surface with a suction hole 741c formed in the center. The hole 741c is connected to a suction tube (not shown). The first cover 741b is a member that surrounds the periphery of the first suction cup 741a.

(5-2-4-2) Second surface holding part 742
The second surface holding portion 742 holds the second surface F2 (see FIG. 3A) of the second large flap Zfa2. As shown in FIG. 3A, the second surface F2 is a surface of the second large flap Zfa2 closer to the fixed end than the folding line BL.

The second surface holder 742 includes a second suction cup 742a and a second cover 742b. The second suction cup 742a has a circular suction surface with a suction hole 742c formed in the center. The hole 742c is connected to a suction tube (not shown). The second cover 742b is a member that surrounds the periphery of the second suction cup 742a.

As shown in Figures 4 and 5, a pair of first surface holder 741 and second surface holder 742 are arranged on the upstream and downstream sides along the conveying direction. In the standby state, the first surface holder 741 and second surface holder 742 are arranged such that the second surface holder 742 is located below the first surface holder 741, and the suction surfaces of the first suction cup 741a and second suction cup 742a are located on the same vertical plane.

When folding the second large flap Zfa2, the first suction cup 741a simply adheres to the first surface F1, and the second suction cup 742a simply adheres to the second surface F2. During folding, the force is transmitted to the first surface F1 by the first cover 741b, and the force is transmitted to the second surface F2 by the second cover 742b.

(5-2-4-3) Parallel crank 743 and crank air cylinder 744
Fig. 6 is a perspective view of the first surface holding part 741 and the second surface holding part 742 as viewed from the rear side. In Fig. 6, the parallel crank 743 is disposed on the rear side of the first surface holding part 741. The parallel crank 743 rotates the first surface holding part 741 by the reciprocating motion of a piston 744a of an air cylinder 744 for a crank so that the first surface holding part 741 is inclined at a predetermined angle with respect to the second surface holding part 742.

In this embodiment, the piston 744a is pushed out to rotate the first surface holding portion 741 so that the first surface holding portion 741 forms an angle of 90° with respect to the second surface holding portion 742.

During actual operation, the first surface holding parts 741 on the upstream and downstream sides in the conveying direction rotate synchronously, but in Figures 5 and 6, in order to show the difference in posture before and after the rotation, the downstream first surface holding part 741 is drawn in the posture before rotation, and the upstream first surface holding part 741 is drawn in the posture after rotation.

(5-2-4-4) Drive motor 745
5, the drive motor 745 is disposed above the downstream side of the lid forming device 340. The drive motor 745 is connected to a frame 74a supporting the first surface holding portion 741 and the second surface holding portion 742 by a link mechanism 74b (see FIG. 7D), and when the drive motor 745 rotates, the frame 74a rotates, so that the first surface holding portion 741 and the second surface holding portion 742 rotate integrally.

(6) Operation of the second large flap folding mechanism 74 The first large flap Zfa1 is folded by the first large flap folding mechanism 71, the first small flap Zfa3 is folded by the first small flap folding mechanism 72, and the second small flap Zfa4 is folded by the second small flap folding mechanism 73, and then the second large flap folding mechanism 74 folds the second large flap Zfa2.

Figures 7A to 7D are diagrams illustrating the folding operation of the second large flap Zfa2 by the first surface holding portion 741 and the second surface holding portion 742. Below, the operation of the second large flap folding mechanism 74 will be explained with reference to these drawings.

(6-1) Suction Operation First, Fig. 7A is a side view of the second large flap folding mechanism 74 when the first surface holding portion 741 and the second surface holding portion 742 suction the second large flap Zfa2 before folding. In Fig. 7A, the first surface holding portion 741 and the second surface holding portion 742 are arranged such that the second surface holding portion 742 is located below the first surface holding portion 741, and the suction surfaces of the first suction cup 741a and the second suction cup 742a are located on the same vertical plane. The relative angle between the first surface holding portion 741 and the second surface holding portion 742 at this time is 180°.

The second large flap Zfa2 of the cardboard box B that reaches the front of the first surface holding portion 741 and the second surface holding portion 742 is pulled toward the first surface holding portion 741 and the second surface holding portion 742 by another mechanism not shown.

The first suction cup 741a and the second suction cup 742a are suctioning, so they suction the surface of the second large flap Zfa2 that is approaching the front of them. At this time, the first suction cup 741a suctions the first surface F1, and the second suction cup 742a suctions the second surface F2.

(6-2) Folding Operation Next, FIG. 7B is a side view of the second large flap folding mechanism 74 when the first surface holding portion 741 and the second surface holding portion 742 adsorb the second large flap Zfa2 and start folding it.

In FIG. 7B, the first surface holding portion 741 and the second surface holding portion 742 tilt toward the inside of the cardboard box B while adsorbing the surface of the second large flap Zfa2. Specifically, the frame 74a that fixes the first surface holding portion 741 and the second surface holding portion 742 rotates a predetermined angle θa by the drive motor 745, causing the first surface holding portion 741 and the second surface holding portion 742 to tilt integrally by the predetermined angle θa toward the inside of the cardboard box B.

The predetermined angle θa varies depending on the box specifications of the cardboard box B. For example, FIG. 9 is a table showing the relationship between the length A of the first surface F1, the length X of the second surface F2, and the predetermined angle θa. In FIG. 9, the figures in the upper column of the table show the side surfaces of the first surface F1 and the second surface F2 after the second large flap Zfa2 is mountain-folded at the fold line BL.

Furthermore, the box specifications of cardboard box B are not all as shown in Figure 9, but are merely an example in which the length of the second large flap Zfa2 is 190 mm.

As shown in FIG. 9, if the combination of the length A of the first surface F1 and the length X of the second surface F2 is different, the predetermined angle θa also changes accordingly.

This is because the second large flap Zfa2 is folded along the folding line BL by the mountain folding operation described below. If the position of the folding line BL changes, the combination of the length A of the first surface F1 and the length X of the second surface F2 will change, and so the specified angle θa must also be changed and adjusted so that the tip of the first surface F1 reaches the appropriate landing point after folding.

The bending angle θb is calculated from the length A of the first surface F1, the length X of the second surface F2, the specified angle θa, and the distance D so that the landing point of the tip of the first surface F1 after bending is at a position distance D from the base of the second large flap Zfa2.

7C is a side view of the second large flap folding mechanism 74 when the first surface holding part 741 and the second surface holding part 742 fold the second large flap into a mountain shape. In Fig. 7C, the first surface holding part 741 rotates so that the relative angle with the second surface holding part 742 becomes the calculated folding angle θb.

Specifically, the parallel crank 743 connected to the back surface of the first surface holding part 741 rotates the first surface holding part 741 by the pushing action of the piston 744a of the crank air cylinder 744 so that the tip of the first surface F1 lands on or in front of the slit portion parallel to the tip of the first surface F1 among the slit Slt3 of the first small flap Zfa3 and the slit Slt4 of the second small flap Zfa4 that have been folded in earlier.

At this time, the first suction cup 741a is adsorbing the first surface F1, and the second suction cup 742a is adsorbing the second surface F2. As a result of the first surface holder 741 rotating, the tip of the first surface F1 lands on or in front of the slit portion.

In this embodiment, the second large flap Zfa2 is inclined at a predetermined angle θa with respect to the vertical plane, and then a mountain fold operation at a folding angle θb is performed, but this is not limited to this. For example, the second large flap Zfa2 may be folded until the inner surface thereof contacts the surfaces of the first small flap Zfa3 and the second small flap Zfa4, and then the first surface holding portion 741 may be rotated in the opposite direction so that the relative angle between the first surface holding portion 741 and the second surface holding portion 742 becomes the folding angle θb.

This causes the tip of the first surface F1 to recede, so that the tip of the first surface F1 reaches above or just before the slit portion.

(6-4) Insertion Operation FIG. 7D is a perspective view of the second large flap folding mechanism 74 when the first surface holding part 741 and the second surface holding part 742 stretch the second large flap Zfa2. The first surface holding part 741 and the second surface holding part 742 stretch the second large flap Zfa2, which has been folded in a mountain shape, into a flat plane. Specifically, the first surface holding part 741 rotates so that the relative angle between the first surface holding part 741 and the second surface holding part 742 is 180°. This is because the parallel crank 743 connected to the back surface of the first surface holding part 741 rotates 90° in the direction opposite to the mountain folding operation due to the retraction operation of the piston 744a of the crank air cylinder 744.

At this time, the first suction cup 741a is adsorbing the first surface F1, and the second suction cup 742a is adsorbing the second surface F2. As a result of the first surface holding portion 741 rotating so that the relative angle with the second surface holding portion 742 is 180°, the first suction cup 741a spreads the first surface F1 in a direction away from the second surface F2.

At this time, the tip of the first surface F1 enters the underside of the first small flap Zfa3 and the second small flap Zfa4 through the slit portions of the slit Slt3 of the first small flap Zfa3 and the slit Slt4 of the second small flap Zfa4 that are parallel to the tip of the first surface F1.

When the tip of the first surface F1 enters the slit Slt3 of the first small flap Zfa3 and the slit Slt4 of the second small flap Zfa4, at least one of the following opening operations is performed: a first surface opening operation that opens the first surface F1 of the second large flap Zfa2 that was adsorbed by the first suction cup 741a, and a second surface opening operation that opens the second surface F2 of the second large flap Zfa2 that was adsorbed by the second suction cup 742a.

These opening operations can be performed at any rotation angle of the second large flap Zfa2. When the second large flap Zfa2 is opened at any position and enters the slit Slt3 of the first small flap Zfa3 and the second small flap Zfa4, the second large flap Zfa2 naturally transitions to a horizontal state.

Therefore, the timing at which the tip of the second large flap Zfa2 enters the slit Slt3 of the first small flap Zfa3 and the slit Slt4 of the second small flap Zfa4 is no longer strict.

Then, as a result of the tip of the first surface F1 entering underneath the first small flap Zfa3 and the second small flap Zfa4, the first large flap Zfa1 is held down from both sides by the first small flap Zfa3 and the second small flap Zfa4, the first small flap Zfa3 and the second small flap Zfa4 are held down from above by the second large flap Zfa2, and the second large flap Zfa2 is held down from above by the first large flap Zfa1, completing a locked state. This improves the stability of the sealed box.

(7) Features (7-1)
In the lid forming device 340, the folded second large flap Zfa2 is stretched so that the tip of the second large flap Zfa2 enters the slit Slt3 of the first small flap Zfa3 and the slit Slt4 of the second small flap Zfa4, so that no unnecessary load is placed on the second large flap Zfa2 and the second large flap Zfa2 does not buckle, and the tip becomes easily inserted into the slit Slt3 of the first small flap Zfa3 and the slit Slt4 of the second small flap Zfa4.

(7-2)
The second large flap folding mechanism 74 of the lid forming device 340 holds the second large flap Zfa2 with the first surface holding part 741 and the second surface holding part 742, and folds the second large flap Zfa2 by moving the first surface holding part 741 and the second surface holding part 742 individually until the relative angle between the first surface F1 and the second surface F2 of the second large flap Zfa2 is reduced to a predetermined angle (90°). Therefore, it is possible to apply an equal load to the first surface F1 and the second surface F2, and folding defects are reduced.

(7-3)
The second large flap folding mechanism 74 of the lid forming device 340 moves the first surface holding part 741 and the second surface holding part 742 individually in a direction in which the relative angle between the first surface F1 and the second surface F2 of the second large flap Zfa2 widens while guiding the tip of the second large flap Zfa2 bent into a mountain shape onto the slit part of the slit Slt3 of the first small flap Zfa3 and the slit Slt4 of the second small flap Zfa4 that is parallel to the tip of the first surface F1, or along the upper surface in front of it, and guides the tip of the second large flap Zfa2 into the slit Slt3 of the first small flap Zfa3 and the slit Slt4 of the second small flap Zfa4. Therefore, no extra load is applied to the second flap, and the tip of the second flap is smoothly inserted into the slit of the first flap without being deformed.

(7-4)
The first surface holding portion 741 has a first suction cup 741a that adsorbs the first surface F1, and the second surface holding portion 742 has a second suction cup 742a that adsorbs the second surface F2, thereby reducing stress concentration on the second large flap Zfa2 compared to when mechanically gripping, and suppressing deformation, etc.

(7-5)
The first surface holding portion 741 has a first cover 741b surrounding a part of the periphery of the first suction cup 741a, and the second surface holding portion 742 has a second cover 742b surrounding a part of the periphery of the second suction cup 742a. As a result, when folding the second large flap Zfa2, the first suction cup 741a only adheres to the first surface F1 and the second suction cup 742a only adheres to the second surface F2, and the force transmission to the first surface F1 during folding is handled by the first cover 741b and the force transmission to the second surface F2 is handled by the second cover 742b, so that the first suction cup 741a and the second suction cup 742a are prevented from being damaged by friction.

(7-6)
When the tip of the first surface F1 enters the slit Slt3 of the first small flap Zfa3 and the slit Slt4 of the second small flap Zfa4, at least one of a first surface opening operation is performed to open the first surface F1 of the second large flap Zfa2 that was adsorbed by the first suction cup 741a, and a second surface opening operation is performed to open the second surface F2 of the second large flap Zfa2 that was adsorbed by the second suction cup 742a.

As a result, the second large flap Zfa2 is opened, the tip of the first surface F1 enters the slit Slt3 of the first small flap Zfa3 and the second small flap Zfa4, and the second large flap Zfa2 naturally transitions to a horizontal state. Therefore, the timing at which the tip of the second large flap Zfa2 enters the slit Slt3 and slit Slt4 is no longer strict.

(8) Others The sealing method using the lid forming device according to the above embodiment is generally called slide lock, and the four top flaps Zfa must be folded inward in the correct order.

However, in cardboard boxes that are repeatedly reused, the creases in the flaps become weak, and it is possible that a flap other than the first large flap Zfa1, which is folded inward first, falls inward first. In such cases, a mechanism is needed to pull that flap outward and hold it in place.

When a hook-shaped member is rotated using a simple rotating mechanism to hook an inward-facing flap and pull it outward, if the length of the box is short, the hook will hit the opposing flap, causing the flap to be tilted inward instead.

To solve this problem, in the past, a rotary air cylinder was attached to the tip of a linear air cylinder, and a hook-shaped member was attached to the rotary air cylinder. The rotary air cylinder rotates while the linear air cylinder extends from above toward the tip of the flap, and when it catches the flap that has fallen inward, the linear cylinder contracts, pulling the flap outward and holding it in place.

This allows a flap that has fallen inward to be pulled outward without hitting the opposing flap.

However, this mechanism requires two air cylinders, which makes the air piping complicated to assemble. Also, to optimize the hook's rotation trajectory, the operating speed of the two air cylinders must be fine-tuned, and because the operating speed of the air cylinders changes with fine adjustments to the air flow rate, it is difficult to ensure stability.

To solve the above problem, a freely rotatable pinion gear is attached to the tip of a single linear air cylinder fixed horizontally. The pinion gear meshes with a rack gear fixed horizontally to form a rack and pinion mechanism.

Figure 8 is a perspective view of the hook-shaped member 751 operated by the rack and pinion mechanism 753. In Figure 8, the hook-shaped member 751 is attached to the shaft 751a to which the pinion gear 753a is fixed, and the hook-shaped member 751 rotates while moving horizontally along the rack 753b as the piston 755a of the hook air cylinder 755 moves linearly.

By optimizing the stroke of the air cylinder 755 for the hook and the diameter of the pinion gear 753a, the rotation trajectory of the tip of the hook-shaped member 751 is determined, and the hook-shaped member 751 moves on a trajectory that lifts up the flap (second small flap Zfa4) that has fallen inward without hitting the opposing flap (first small flap Zfa3).

As described above, the hook-shaped member 751 is operated by a single hook air cylinder 755, so air piping is not complicated. In addition, regardless of the operating speed, the rotational trajectory of the hook-shaped member 751 is always constant, so the flap (second small flap Zfa4) can be lifted stably regardless of the air flow rate.

Second Embodiment
In the first embodiment, the folding operation of the second large flap Zfa2 is performed by combining the first suction cup 741a, the second suction cup 742a, the crank air cylinder 744, and the drive motor 745 (servo motor).

However, there is a risk that the air cylinder will not achieve the desired operation due to factors such as deterioration over time or insufficient adjustment. Therefore, it is necessary to control the first suction cup 741a, the second suction cup 742a, and the drive motor 745 while checking the state (e.g., operation time) of the crank air cylinder 744.

The crank air cylinder 744 only has a sensor that detects the start and end points of the movement of the piston 744a, and is unable to measure the movement time of the piston 744a in real time.

Therefore, in the second embodiment, the controller 40 stores the time interval between the start and end points of the most recent operation of the piston 744a as the operation time of the piston 744a, and changes the operation pattern (speed, acceleration, deceleration) of the drive motor 745 and the release timing of the first suction cup 741a and the second suction cup 742a to optimal states according to the operation time.

Figure 10 is a block diagram showing the electrical connections between the controller 40, the first suction cup 741a, the second suction cup 742a, the piston 744a of the crank air cylinder 744, and the drive motor 745. Also, Figure 11 is a flowchart of the folding operation of the second large flap Zfa2.

First, in FIG. 10, the first suction valve 741v, the second suction valve 742v, the directional control valve 744v, the first position sensor 744ss, the second position sensor 744sf, and the drive motor 745 are connected to the controller 40.

The first suction valve 741v is a valve that suctions or releases the first suction cup 741a. When the first suction valve 741v is open, the first suction cup 741a performs a suction operation, and when the first suction valve 741v is closed, the first suction cup 741a releases suction.

The second suction valve 742v is a valve that suctions or releases the second suction cup 742a. When the second suction valve 742v is open, the second suction cup 742a performs a suction operation, and when the second suction valve 742v is closed, the second suction cup 742a releases suction.

The directional control valve 744v is a valve that reciprocates the piston 744a of the crank air cylinder 744. When the directional control valve 744v is in the forward mode, the piston 744a moves forward, and when the directional control valve 744v is in the return mode, the piston 744a moves backward.

The first position sensor 744ss is a sensor that detects when the piston 744a is at the origin position. The second position sensor 744sf is a sensor that detects when the piston 744a is at the end point of the forward path.

The drive motor 745 is a servo motor. When the drive motor 745 rotates, the frame 74a rotates, so that the first surface holding portion 741 and the second surface holding portion 742 rotate integrally.

(1) Folding Operation of the Second Large Flap Zfa2 Below, the coordinated operations of the first suction cup 741a, the second suction cup 742a, the crank air cylinder 744, and the drive motor 745 will be explained with reference to the flowchart of the folding operation of the second large flap Zfa2 (Figure 11).

(Step S1)
In step S1, the controller 40 determines whether or not an adsorption command has been issued, and if it determines that an adsorption command has been issued, the process proceeds to step S2, but if it determines that an adsorption command has not been issued, the determination operation continues.

(Step S2)
Next, in step S2, the controller 40 opens the first suction valve 741v and the second suction valve 742v to cause the first suction cup 741a to suction the first surface F1 and the second suction cup 742a to suction the second surface F2.

(Step S3)
Next, in step S3, the controller 40 switches the directional control valve 744v to the forward mode in which the piston 744a moves in the forward direction, thereby operating the piston 744a and starting the mountain-folding operation of the second large flap Zfa2.

(Step S4)
Next, in step S4, the controller 40 starts the timer 405 and counts the elapsed time t from the point in time when it is detected via the first position sensor 744ss that the piston 744a has left the original position.

(Step S5)
Next, in step S5, the controller 40 operates the drive motor 745 to tilt the second large flap Zfa2 by the angle θa with respect to the vertical plane. In the second embodiment, the drive motor 745 operates with a delay from the operation of the piston 744a.

In addition, the controller 40 estimates the position of the piston 744a based on the previously stored forward movement time, and adjusts the acceleration, speed, and deceleration of the drive motor 745 based on the estimated position.

(Step S6)
Next, in step S6, the controller 40 determines whether or not the piston 744a has reached the end position in the forward direction via the second position sensor 744sf. If the controller 40 determines that the piston 744a has reached the end position, the controller 40 proceeds to step S7, and if the controller 40 does not determine that the piston 744a has reached the end position, the controller 40 continues the determination.

(Step S7)
Next, in step S7, the controller 40 stores the elapsed time t from the time when it is detected that the piston 744a has left the origin position to the time when it is detected that the piston 744a has reached the end position in the memory 403 as the forward movement time tA(n) of the piston 744a, and resets the timer 405.

The controller 40 estimates the position of the piston 744a based on the previously stored forward movement time tA(n-1), and adjusts the acceleration, speed, and deceleration of the drive motor 745 based on the estimated position.

The forward movement time tA(n) stored here is therefore used to estimate the position of the piston 744a during the next (n+1) forward movement.

(Step S8)
Next, in step S8, the controller 40 switches the directional control valve 744v to the return mode in which the piston 744a moves in the return direction.

(Step S9)
Next, in step S9, the controller 40 starts the timer 405, and counts the elapsed time t from the point in time when it is detected via the second position sensor 744sf that the piston 744a has left the end position.

(Step S10)
Next, in step S10, the controller 40 estimates the position of the piston 744a based on the previously stored return movement time, and releases the suction of the first surface F1 by the first suction cup 741a and the suction of the second surface F2 by the second suction cup 742a based on the estimated position. Specifically, the controller 40 closes the first suction valve 741v and the second suction valve 742v to release the suction of the first surface F1 by the first suction cup 741a and the suction of the second surface F2 by the second suction cup 742a.

(Step S11)
Next, in step S11, the controller 40 determines whether or not the piston 744a has reached the origin position via the first position sensor 744ss. If the controller 40 determines that the piston 744a has reached the origin position, the process proceeds to step S12, and if the controller 40 does not determine that the piston 744a has reached the origin position, the controller 40 continues the determination.

(Step S12)
Next, in step S12, the controller 40 stores the elapsed time t from the time when it is detected that the piston 744a has left the end position to the time when it is detected that the piston 744a has reached the origin position in the memory 403 as the return movement time tB(n) of the piston 744a, and resets the timer 405.

The controller 40 estimates the position of the piston 744a based on the previously stored return movement time tB(n-1), and adjusts the timing for releasing the suction of the first surface F1 by the first suction cup 741a and the timing for releasing the suction of the second surface F2 by the second suction cup 742a based on the estimated position.

The return movement time tB(n) stored here is therefore used to estimate the position of the next (n+1) return movement of piston 744a.

(Step S13)
Then, in step S13, the controller 40 rotates the drive motor 745 in the reverse direction to rotate the first suction cup 741a and the second suction cup 742a by an angle θa so that they are parallel to the vertical plane.

As described above, the controller 40 adjusts the acceleration, speed, and deceleration of the drive motor 745, the timing at which the first suction cup 741a releases the suction of the first surface F1, and the timing at which the second suction cup 742a releases the suction of the second surface F2, based on the previous forward movement time and return movement time of the piston 744a.

(2) Features of the Second Embodiment For example, when the forward movement time of the piston 744a becomes longer due to deterioration over time, even though the drive motor 745 rotates the second large flap Zfa2 by the angle θa, the mountain folding movement is not completed, and there is a risk that the tip of the first surface F1 of the second large flap Zfa2 will not reach the target position of the slit Slt3 and the slit Slt4.

However, the controller 40 adjusts the acceleration, speed, and deceleration of the drive motor 745 based on the previous forward movement time of the piston 744a, so that the tip of the first surface F1 of the second large flap Zfa2 can reach the target position of the slits Slt3 and Slt4.

In addition, if the return movement time of the piston 744a becomes longer due to deterioration over time, there is a risk that the suction of the first surface F1 by the first suction cup 741a and the suction of the second surface F2 by the second suction cup 742a will be released when the first surface holding portion 741 and the second surface holding portion 742 have not fully extended the second large flap Zfa2.

However, by adjusting the timing at which the first suction cup 741a releases the suction of the first surface F1 and the timing at which the second suction cup 742a releases the suction of the second surface F2 based on the previous return movement time of the piston 744a, the suction of the first surface F1 by the first suction cup 741a and the suction of the second surface F2 by the second suction cup 742a are released after the first surface holding portion 741 and the second surface holding portion 742 fully extend the second large flap Zfa2.

Therefore, even if the operation of the piston 744a of the crank air cylinder 744 is unstable, the first suction cup 741a, the second suction cup 742a, and the drive motor 745 perform operations appropriate to the operation time of the piston 744a, thereby stabilizing the series of operations of the second large flap folding mechanism 74.

Third Embodiment
The structure of the third embodiment is the same as that of the first and second embodiments, but the insertion operation of the second large flap Zfa2 into the slits Slt3 and Slt4 differs from that of the first and second embodiments.

(1) Insertion Operation Fig. 12A is a schematic diagram showing a normal insertion operation of the second large flap Zfa2. Fig. 12B is a schematic diagram showing the insertion operation of the second large flap Zfa2 when the filling rate of the bags (products G) to be inserted into the cardboard box B is high.

As shown in FIG. 12A, the corners of the tip of the first surface F1 of the second large flap Zfa2, which would normally be bent into a mountain shape, enter the slits Slt3 and Slt4, and then the second large flap Zfa2 is stretched into a flat plane, and the corners of the tip of the first surface F1 enter the underside of the first small flap Zfa3 and the second small flap Zfa4 from the slits Slt3 and Slt4.

However, as shown in FIG. 12B, when the packing rate of the bags in the cardboard box B is high, the tip of the first surface F1 to be inserted may interfere with the bag, making it difficult to insert the flap properly.

In addition, in the case of a cardboard box with a lid over the slit, the lid may get in the way and make it difficult to insert the first surface F1 into the slit.

Therefore, in the third embodiment, the second large flap folding mechanism 74 inserts the tip corner of the first surface F1 of the second large flap Zfa2 deep inward through the slits Slt3 and Slt4, then lifts the second large flap Zfa2 to a degree that prevents the tip corner of the first surface F1 from coming out of the slits Slt3 and Slt4, and then inserts the tip of the first surface F1 again.

Figure 12C is a schematic diagram showing the insertion operation of the second large flap Zfa2 in the third embodiment. In Figure 12C, the second large flap folding mechanism 74 inserts the tip corner of the first surface F1 of the second large flap Zfa2, which is folded into a mountain shape, into the slits Slt3 and Slt4 as a first operation. At that time, the tip corner is inserted into the slits Slt3 and Slt4 in a first range from the free end of the first surface F1 to a first distance L1 away. This state is called the first insertion state.

After the first insertion state is formed, the tip corner is inserted into the slits Slt3 and Slt4 in a second range from the free end of the first surface F1 to a second range that is a second dimension L2 smaller than the first dimension L1. This state is called the second insertion state.

After forming the second insertion state, the second large flap folding mechanism 74 performs a second operation by stretching the second large flap Zfa2 and further inserting the tip corners inserted into the slits Slt3 and Slt4 toward the back side of the slits Slt3 and Slt4.

(2) Features of the third embodiment As described above, even if the bag filling rate of the cardboard box B is high, the bag is pushed into the second large flap Zfa2 by forming the first insertion state in the first operation, so that interference between the second large flap Zfa2 and the bag can be suppressed during the subsequent second operation.

In addition, even if the slit has a lid, the lid can be opened in the first insertion state, so failure to insert the second large flap Zfa2 due to the presence of the lid is avoided.

The insertion operation of the second large flap Zfa2 into the slits Slt3 and Slt4 in the third embodiment can also be applied to the first embodiment.

(3) Modification of the Third Embodiment When the insertion operation of the second large flap Zfa2 is completed, a sensor may be used to determine whether the insertion operation has been completed normally.

Figure 13 is a schematic diagram showing a series of operations of the second large flap folding mechanism 74 when the insertion operation of the second large flap Zfa2 is not completed normally.

In FIG. 13, the sensor 746 is a photoelectric sensor. The sensor 746 has a light projector 746a and a light receiver 746b. The light projector 746a and the light receiver 746b are arranged at a predetermined height with a predetermined distance between them, and light (e.g., infrared light) is emitted from the light projector 746a. If the light is not blocked and is detected by the light receiver 746b, the controller 40 determines that there is no object detected between the light projector 746a and the light receiver 746b.

The specified height position is set at a specified distance above the top end of cardboard box B.

As shown in FIG. 13, if the insertion operation of the second large flap Zfa2 is not completed normally and the bending line BL portion is raised instead of being flat, the light emitted from the light-projector 746a is blocked by the raised bending line BL portion and is not detected by the light-receiver 746b.

In such a case, the controller 40 determines that the insertion operation of the second large flap Zfa2 was not completed normally. Then, as shown in FIG. 13, the controller 40 tilts the first surface holding portion 741 and the second surface holding portion 742 toward the cardboard box B to push in the second large flap Zfa2.

Alternatively, the controller 40 may adsorb the second large flap Zfa2 via the first surface holding portion 741 and the second surface holding portion 742 and perform the folding operation again.

In this modified example, even if a folding error occurs, the operator does not need to stop the device, and a decrease in the device's operating rate can be suppressed.

This modified example is not limited to the third embodiment, but can also be applied to the first and second embodiments.

Fourth Embodiment
The structure of the fourth embodiment differs from that of the first embodiment in that the mountain folding operation for folding the second large flap Zfa2 along the folding line BL is performed by a servo motor 747 instead of the crank air cylinder 744.

In the first embodiment, as shown in FIG. 9, the second large flap Zfa2 is folded along the folding line BL by a mountain folding operation. Therefore, if the position of the folding line BL changes, the combination of the length A of the first surface F1 and the length X of the second surface F2 changes, and the specified angle θa is also changed, so that the tip of the first surface F1 after folding reaches an appropriate landing point.

The bending angle θb is calculated from the length A of the first surface F1, the length X of the second surface F2, the predetermined angle θa, and the distance D so that the landing point of the tip of the first surface F1 after bending is at a position distance D from the base of the second large flap Zfa2, but in the first embodiment, the bending angle θb is fixed at 90°.

This is because the rotation of the first surface holding part 741 is driven by a piston 744a provided on a parallel crank 743, and it is not easy to change or adjust the rotation angle.

In the fourth embodiment, as shown in FIG. 14 (a schematic side view of the second large flap folding mechanism), the first surface holding part 741 is rotated by a servo motor 747 in order to easily set the relative angle between the first surface holding part 741 and the second surface holding part 742 to the desired folding angle θb. In the fourth embodiment, the folding angle θb is set within the range of 90 to 120 degrees.

40 Controller (control unit)
72 First small flap folding mechanism (first folding mechanism)
73 Second small flap folding mechanism (first folding mechanism)
74 Second large flap folding mechanism (second folding mechanism)
405 Timer (measurement unit)
741 First surface holding unit (second driving unit)
741a First suction cup 741b First cover 741v First suction valve 742 Second surface holding part (second driving part)
742a: second suction cup 742b: second cover 742v: second suction valve 744: crank air cylinder (third drive unit)
744a Piston 744v Directional switching valve 744ss First position sensor 744sf Second position sensor 745 Drive motor (first drive unit)
746 Photoelectric sensor (detection unit)
747 Servo motor 340 Lid forming device B Cardboard box BL Folding line F1 First surface F2 Second surface Slt3 Slit Slt4 Slit Zfb2 Second large flap (second flap)
Zfb3 First small flap (first flap)
Zfb4 Second small flap (first flap)

Special Publication No. 58-3881

Claims (11)

A lid forming device for forming a lid for a cardboard box using a first flap having a slit and a second flap that is folded in a mountain shape and then stretched out, the first flap being one of a group of flaps that are cantilevered around the edge of an opening of the cardboard box, the second flap comprising:
a first folding mechanism that folds the first flap in a direction to close the opening;
a second folding mechanism that performs a first operation of folding the second flap into a mountain shape, inserting the second flap folded into the mountain shape into the slit to a position a first dimension away from a tip of the second flap, and then returning the second flap to a state where it was inserted into the slit to a position a second dimension away from the tip, the second dimension being shorter than the first dimension, and performing a second operation of further inserting the tip of the second flap inserted into the slit toward the back side of the slit in a process of stretching the second flap after the first operation ;
Equipped with
The second folding mechanism includes:
a first holding portion that holds a first surface of the second flap closer to a free end than a predetermined folding line;
a second holding portion that holds a second surface closer to the fixed end than the bending line;
Including,
Lid forming device. the second folding mechanism holds the second flap by the first holding portion and the second holding portion, and folds the second flap by individually moving the first holding portion and the second holding portion until a relative angle between the first surface and the second surface of the second flap is reduced to a predetermined angle.
The cap forming apparatus of claim 1 . The second folding mechanism moves the first holding portion and the second holding portion individually in a direction in which a relative angle between the first surface and the second surface of the second flap increases while aligning a tip end of the folded second flap along an upper surface of the first flap, and guides a free end of the second flap to the slit of the first flap.
The cap forming apparatus according to claim 1 or 2. the first holding unit has a first suction device that suctions the first surface,
the second holding portion has a second suction device that suctions the second surface,
The cap forming apparatus according to any one of claims 1 to 3. the first holding unit further includes a first cover surrounding a portion of a periphery of the first adsorber,
the second holding unit further includes a second cover surrounding a portion of the periphery of the second adsorber;
The cap forming apparatus according to claim 4. the first suction unit selectively switches a timing for releasing the first surface after suctioning the first surface;
the second suction device selectively switches a timing for releasing the second surface after suctioning the second surface,
The cap forming apparatus according to claim 4. The second folding mechanism further includes a drive unit that drives the first holding unit and the second holding unit until a relative angle between the first surface and the second surface of the second flap becomes a predetermined angle.
The cap forming apparatus of claim 1 . The predetermined angle is set within a range of 90 to 120 degrees.
The cap forming apparatus of claim 7 . A lid forming device for forming a lid for a cardboard box using a first flap having a slit and a second flap that is folded in a mountain shape and then stretched out, the first flap being one of a group of flaps that are cantilevered around the edge of an opening of the cardboard box, the second flap comprising:
a first folding mechanism that folds the first flap in a direction to close the opening;
a second folding mechanism that folds the second flap into a mountain shape and extends the second flap, and inserts a portion of the second flap into the slit of the first flap during the process of extending the second flap;
A control unit that controls the second folding mechanism ;
Equipped with
The second folding mechanism includes:
a first holding portion that suction-holds a first surface of the second flap that is closer to a free end than a predetermined folding line;
a second holding portion that suction-holds a second surface closer to the fixed end than the bending line;
A first drive unit that rotates the second flap around the fixed end of the second surface;
a second drive unit that holds and releases the first surface and the second surface of the second flap by the first holding unit and the second holding unit;
a third drive unit that drives the first holding unit and the second holding unit until a relative angle between the first surface and the second surface of the second flap becomes a predetermined angle;
A measurement unit that measures at least an operation time of the third drive unit and outputs the measurement time to the control unit;
Including,
The control unit adjusts the operation of the first drive unit and/or the operation of the second drive unit based on the operation time of the third drive unit.
Lid forming device. The first driving unit is a servo motor, and the third driving unit is an air cylinder.
The cap forming apparatus of claim 9 . A lid forming device for forming a lid for a cardboard box using a first flap having a slit and a second flap that is folded in a mountain shape and then stretched out, the first flap being one of a group of flaps that are cantilevered around the edge of an opening of the cardboard box, the second flap comprising:
a first folding mechanism that folds the first flap in a direction to close the opening;
a second folding mechanism that folds the second flap into a mountain shape and extends the second flap, and inserts a portion of the second flap into the slit of the first flap during the process of extending the second flap;
A control unit that controls the second folding mechanism;
A detection unit that detects a height position of the second flap folded by the second folding mechanism from a predetermined reference plane and outputs the height position to the control unit;
Equipped with
The second folding mechanism includes:
a first holding portion that suction-holds a first surface of the second flap that is closer to a free end than a predetermined folding line;
a second holding portion that suction-holds a second surface closer to the fixed end than the bending line;
Including,
When the control unit determines that the height position is not within a predetermined range, the control unit causes the second folding mechanism to fold the second flap again.
Lid forming device.

Images