Sealing device

Abstract

To provide a sealing device capable of enhancing a throughput capacity of a sealing process in a filling / sealing system of a gable-top paper container and reducing a manufacturing cost thereof.SOLUTION: A sealing device bends the opposite surfaces on both sides of an opening of a gable-top paper container inward by bending guides 30 and 35, and holds and joins the upper edges of the opposite surfaces by a pair of holding members 72. An external frame 23 is disposed so as to be liftable, and has the bending guides 30 and 35 disposed therein. An intermediate frame 40 is disposed to be movable up and down with respect to the external frame 23. An internal frame 50 is disposed to be movable up and down with respect to the intermediate frame 40. A heater 60 is moved between a heating position facing the opening of the paper container C and a standby position separated from the heating position by an air cylinder 61 for lifting the heater. A first arm 70 is pivotally supported by the intermediate frame 40 and has the holding member 72 disposed at one end thereof. A second arm 71 is connected to the other end of the first arm 70 and is pivotally supported by the internal frame 50.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a gable-top paper container filled with liquid contents such as milk, and more specifically, to a sealing device that forms the opening of a gable-top paper container filled with contents into a gable roof shape and seals it. [Background technology]

[0002] A sealing device disclosed in Patent Document 1 is known as such a conventional sealing device. A filling and sealing system provided with this sealing device is configured to fill a paper container formed into a bottomed rectangular tubular shape with liquid while the paper container is intermittently conveyed by a conveyor, and to seal the top of the paper container. That is, after filling the paper container with liquid in the filling section, a heating device downstream of the filling section heats the thermoplastic resin at the opening of the paper container with hot air, and a sealing head downstream of the heating device closes the opening and pressurizes it to form and seal the top of the container in a gable roof shape. A similar sealing device is also disclosed in Patent Document 2, and this sealing device is also configured to fill the paper container with liquid while intermittently conveying a bottomed rectangular tubular paper container, and then heat the opening and seal the top. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-270010 A [Patent Document 2] JP 2006-82844 A Summary of the Invention [Problem to be solved by the invention]

[0004] The conventional filling and sealing system described above is configured to convey paper containers intermittently, and the heating device and sealing device are installed in separate stations. Therefore, there is a limit to the improvement of processing capacity due to the time required for the lifting and lowering of the sealing device and the conveyance of the paper containers, and there is also a problem that the need to provide two stations increases manufacturing costs.

[0005] An object of the present invention is to provide a sealing device in a filling and sealing system that can increase the processing capacity of the sealing process for gable-top paper containers and reduce manufacturing costs. [Means for solving the problem]

[0006] The present invention is a sealing device for gable-top paper containers that folds opposing surfaces on both sides of an opening of a gable-top paper container inward using a folding guide and joins the upper edges of the opposing surfaces by clamping them with a pair of clamping members, and is characterized by comprising an external frame that is arranged to be able to be raised and lowered and in which a folding guide is arranged, an intermediate frame that is arranged to be able to be raised and lowered relative to the external frame, an internal frame that is arranged to be able to be raised and lowered relative to the intermediate frame, a heater that heats the opening of the paper container, heater moving means that moves the heater between a heating position facing the opening of the paper container and a standby position spaced from the heating position, and a link mechanism having a first arm journaled to the intermediate frame and having a clamping member at one end, and a second arm that is connected to the other end of the first arm and journaled to the internal frame. Effect of the Invention

[0007] According to the present invention, a sealing device can be obtained that can increase the processing capacity of the sealing process for gable-top paper containers in a filling and sealing system and reduce manufacturing costs. [Brief description of the drawings]

[0008] [Figure 1] 1 is a plan view showing an overall configuration of a filling and sealing system provided with a sealing device according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view showing a gable-top carton being processed by a sealing device. [Diagram 3] 2 is a view showing the seal head taken along line AA in FIG. 1. [Figure 4] FIG. 4 is a side view showing the first and second folding guides in an initial state. [Diagram 5] FIG. 4 is a side view showing the first and second folding guides in a folded state. [Figure 6] FIG. 4 is a diagram showing a sealing operation by a seal head. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The present invention will be described below based on the illustrated embodiments. 1 shows the overall configuration of a filling and sealing system provided with a sealing device 10 according to one embodiment of the present invention. In this system, an endless chain 12 is looped around the bodies of the sealing device 10 and the filling device 11, and the sealing device 10 and the filling device 11 rotate continuously about their axes. Filling heads 16 are attached to the body of the filling device 11 at regular intervals along its periphery, and sealing heads 17 are attached to the body of the sealing device 10 at regular intervals along its periphery. That is, in this embodiment, paper containers C are continuously transported, and as described below, filling and sealing operations are performed on the paper containers C during the continuous transport.

[0010] Grippers 13 are attached to the endless chain 12 at regular intervals. A supply star wheel 14 is provided near the filling device 11, and empty paper containers C formed into a bottomed rectangular tube are delivered from the supply star wheel 14 to the filling device 11. In the filling device 11, a filling head 16 fills the paper containers C with liquid contents while it is continuously rotating, and the paper containers C are transported to the sealing device 10. In the sealing device 10, a seal head 17 forms the opening of the paper container C into a gable roof shape and seals the opening while it is continuously rotating. The gable-top paper containers C formed in this way are delivered from the sealing device 10 to a discharge star wheel 15 and transported to the next process.

[0011] FIG. 2 shows a gable-top paper container C. The body of the gable-top paper container C has a rectangular tubular shape, and the top is formed into a gable roof shape and sealed. The top is composed of a gable roof panel R, a gable wall panel S, and a top seal part T, and a resin plug D is attached to the gable roof panel R. As described later, in the sealing device 10, the inner wall surface of the opening of the bottomed rectangular tubular body is first heated by a heater, and the thermoplastic resin applied to the inner wall surface melts. Next, the front and rear wall surfaces of the opening are folded inward by a first folding guide to form the gable wall panel S, and the left and right side wall surfaces are folded inward by a second folding guide to form the gable roof panel R, and the top seal part T, which is the upper edge of the gable roof panel R, is clamped and joined by a pair of clamping members.

[0012] 3 shows the seal head 17, and is a view taken along the line AA in FIG. 1. The main body 20 of the sealing device 10 has a pair of horizontal plates 21, 22 that are arranged parallel to each other and can rotate about their axis, and an outer frame 23 of the seal head 17 is provided below the lower horizontal plate 21. An outer frame lifting shaft 24 that extends vertically upward from the upper surface of the outer frame 23 is supported by the pair of horizontal plates 21, 22 so that it can be raised and lowered. A cam member 25 is provided between the horizontal plates 21, 22, and a cam follower 27 attached to the outer frame lifting shaft 24 engages with a cam surface 26 formed on the upper surface of the cam member 25. Therefore, as the main body 20 rotates about its axis, the outer frame 23 rises and falls according to the shape of the cam surface 26.

[0013] On the bottom surface of the external frame 23, first and second folding guides 30, 35 are arranged to fold the opening of the paper container C inward and join them to form the top of the gable roof shape. As shown in Figures 4 and 5, the first folding guide 30 is for forming the gable wall panel S and has a triangular prism shape extending in a direction perpendicular to the paper surface, and the cross-sectional shape of this triangular prism corresponds to the shape of the gable roof panel R. A pair of first folding guides 30 are provided along a direction perpendicular to the paper surface, and are driven to move in directions toward and away from each other. For this reason, an air cylinder 31 for driving the first folding guide 30 is provided on the bottom surface of the external frame 23, and the piston of the air cylinder 31 is connected to the first folding guide 30 via a bracket 32.

[0014] The second folding guide 35 is for forming the gable roof panel R, and has a flat plate shape extending in a direction perpendicular to the paper. The second folding guide 35 is provided as a pair on either side of the first folding guide 30, and is swingable about a swing shaft 36 provided on the bottom surface of the external frame 23, and is driven so that its tip portions move in directions toward and away from each other. For this reason, an air cylinder 37 for driving the second folding guide 35 is fixed to the bottom surface of the external frame 23 via a bracket 38. The second folding guide 35 has a notch (not shown) formed therein to avoid interference with the plug D.

[0015] 3 again, the configurations of the intermediate frame 40 and the inner frame 50 will be described. The intermediate frame 40 is provided inside the outer frame 23 and can be raised and lowered relative to the outer frame 23. A cylindrical intermediate frame lifting shaft 41 is provided on the upper surface of the intermediate frame 40, and the intermediate frame lifting shaft 41 penetrates the lower horizontal plate 21 of the main body 20 of the sealing device 10 to reach the middle between the horizontal plates 21, 22. A cam follower 42 is provided on the upper end of the intermediate frame lifting shaft 41, and the cam follower 42 engages with a cam groove 43 formed on the side surface of the cam member 25. Therefore, as the main body 20 rotates about its axis, the intermediate frame 40 rises and falls according to the shape of the cam groove 43.

[0016] The inner frame 50 is provided inside the intermediate frame 40 and has a pair of horizontal plates 51 and 52. The pair of horizontal plates 51 and 52 can be raised and lowered relative to the intermediate frame 40. An inner frame lifting shaft 53 is provided on the upper surface of the upper horizontal plate 52, and the inner frame lifting shaft 53 passes through the intermediate frame lifting shaft 41 and protrudes upward from the upper horizontal plate 22 of the main body 20 of the sealing device 10. A cam follower 54 is provided on the inner frame lifting shaft 53, and the cam follower 54 engages with a cam groove 55 formed on the side of the cam member 25. Therefore, with the rotation of the main body 20 around its axis, the horizontal plates 51 and 52 of the inner frame 50 rise and fall according to the shape of the cam groove 55. The outer frame lifting shaft 24 is provided at a position overlapping with the intermediate frame lifting shaft 41 and the inner frame lifting shaft 53, but for ease of viewing, they are shown in positions offset from each other in FIG. 3.

[0017] A heater 60 for heating the opening of the paper container C is provided below the intermediate frame 40. The heater 60 is provided at the lower end of a piston 62 of an air cylinder 61 for lifting and lowering the heater, and the air cylinder 61 for lifting and lowering the heater is connected to the external frame 23 via a bracket 63. By driving the external frame 23 and / or the air cylinder 61 for lifting and lowering the heater, the heater 60 can be moved between a heating position facing the opening of the paper container C and a standby position spaced above the heating position. In other words, the external frame 23 and the air cylinder 61 for lifting and lowering the heater constitute a heater moving means.

[0018] A pair of first arms 70 are pivotally supported by the connecting member 44 attached to the lower surface of the intermediate frame 40. Meanwhile, a pair of second arms 71 are pivotally supported by the connecting member 56 attached to the lower surface of the lower horizontal plate 51 of the internal frame 50. One end of the first arm 70 extends downward from the connecting member 44, and a clamping member 72 is provided at its lower end. The other end of the first arm 70 extends upward beyond the connecting member 44, and a lower end of the second arm 71 is pivotally attached to its upper end, and the first arm 70 and the second arm 71 form a link mechanism. The internal frame 50 can be raised and lowered relative to the intermediate frame 40 in accordance with the shapes of the cam grooves 43, 55, and the pair of clamping members 72 expand and contract by raising and lowering the internal frame 50 while keeping the height position of the intermediate frame 40 fixed.

[0019] In the internal frame 50, the lower horizontal plate 51 can be slightly displaced in the vertical direction relative to the upper horizontal plate 52. A load-applying air cylinder 57 is attached to the underside of the upper horizontal plate 52, and a piston 58 of the load-applying air cylinder 57 is connected to the lower horizontal plate 51. By operating the load-applying air cylinder 57, the lower horizontal plate 51 can be raised and lowered relative to the upper horizontal plate 52, and the closing force of the clamping member 72 can be finely adjusted via a link mechanism consisting of first and second arms 70, 71.

[0020] The operation of the sealing device will be described with reference to FIG. When the paper container C is transported to the sealing device 10 with the liquid contents filled and the opening open, the outer frame 23, the intermediate frame 40, and the inner frame 50 are lowered together as shown in (a), and the heater raising and lowering air cylinder 61 is driven to lower the heater 60. As a result, the heater 60 is lowered to the heating position and is positioned inside the upper end of the opening of the paper container C, facing the inner wall surface of the opening and heating it, and the thermoplastic resin applied to the inner wall surface melts. After this, as shown in (b), with the height positions of the outer frame 23, the intermediate frame 40, and the inner frame 50 fixed, only the heater 60 is raised and separated from the opening of the paper container C, and returns to the standby position, where heating ends.

[0021] Next, as shown by the symbol (c), with the height positions of the outer frame 23 and the intermediate frame 40 fixed, only the inner frame 50 descends, whereby the clamping members 72 are closed by the action of the link mechanism. At this time, the pair of clamping members 72 are positioned so as to form a gap slightly larger than the thickness of the top seal portion T of the paper container C. Simultaneously with this closing action of the clamping members 72, the pair of first folding guides 30 move in directions approaching each other, and the pair of second folding guides 35 also move in directions approaching each other. As a result, the opening of the paper container C is formed into a gable roof shape.

[0022] The reason why a gap is formed between the pair of clamping members 72 in this manner is that if the clamping members 72 were lowered in the state shown in symbol (b), the clamping members 72 would interfere with the resin plug D of the gable roof panel R. In other words, by closing the pair of clamping members 72 to the extent that a gap is formed, such interference is avoided.

[0023] Next, as shown by (d), the inner frame 50 and the intermediate frame 40 are lowered while maintaining their relative height relationship, and are positioned so that the top seal portion T of the paper container C fits into the gap between the clamping members 72. Then, as shown by (e), with the height position of the intermediate frame 40 fixed, only the inner frame 50 is lowered, and the clamping members 72 close to seal the top seal portion T. At this time, the load-applying air cylinder 57 is operated and fine-tuned so that the closing force of the clamping members 72 is an appropriate magnitude. It is also possible to use a spring instead of the load-applying air cylinder 57.

[0024] When the top seal portion T is joined, the inner frame 50 rises relative to the intermediate frame 40, which releases the clamping members 72 and moves them away from the top seal portion T. In addition, the outer frame 23, the intermediate frame 40, and the inner frame 50 rise and return to their initial positions.

[0025] As described above, the sealing device of this embodiment is a sealing device 10 that folds opposing surfaces on both sides of the opening of a paper container C inward using folding guides 30, 35 and then clamps and joins the upper edges of the opposing surfaces with a pair of clamping members 72, and is configured such that folding guides 30, 35 and a heater 60 are provided on a single sealing head 17, and the heater 60 performs the heating and sealing process for the opening of the paper container C. Therefore, compared to the conventional configuration in which the heating device and sealing device are located in separate stations, the processing capacity of the sealing process for gable-top paper containers C in the fill seal system can be improved and manufacturing costs can be significantly reduced.

[0026] The present invention is not limited to a rotary machine in which an endless chain 12 is wound around the main bodies of the sealing device 10 and the filling device 11 as in the embodiment, but can also be applied to a line machine in which the sealing device 10 and the filling device 11 are arranged in a straight line. [Explanation of symbols]

[0027] 23 External Frame 30, 35 Folding guide 40 Intermediate Frame 50 Internal Frame 60 Heater 61 Air cylinder for lifting heater (heater moving means) 70 First Arm 71 Second Arm 72 Clamping member

Claims

[Claim 1] A sealing device for a gable-top paper container, which folds opposing surfaces on both sides of an opening of a gable-top paper container inward by a folding guide, and clamps and joins the upper edges of the opposing surfaces with a pair of clamping members, an external frame provided so as to be movable up and down and in which the bending guide is disposed; an intermediate frame that is vertically movable relative to the outer frame; an inner frame that is vertically movable relative to the intermediate frame; A heater for heating the opening of the paper container; a heater moving means for moving the heater between a heating position facing the opening of the paper container and a standby position spaced from the heating position; a link mechanism including a first arm pivotally supported by the intermediate frame and having the clamping member at one end thereof, and a second arm connected to the other end of the first arm and pivotally supported by the inner frame; A sealing device comprising:

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