JPS61190407A - Film turning-in mechanism of packaging machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a film folding mechanism for a packaging machine that wraps items to be packaged with a stretch film, and particularly relates to a film folding mechanism of a type in which left and right folding plates move straight. This relates to improvements to the board.

[Prior art]

Many years have already passed since packaging machines have been put into practical use that place an object to be packaged in a dish-shaped container and wrap the object together with a transparent stretch film. During this time, various packaging machines have been proposed and improvements have been made. The same applies to the film folding mechanism of a packaging machine, and the present applicant has also previously developed and filed an application for a folding mechanism of a packaging machine (Japanese Patent Application No. 182466/1982).

FIGS. 12(a) to 12(d) are diagrams for explaining the outline and operation of the film folding mechanism previously filed by Reijin Motoyama. The folding mechanism includes a pair of left and right folding plates 21 and 22 that are arranged facing each other at a predetermined position of the packaging machine and slide in the left and right horizontal directions, and the left and right folding plates 21
．． A front folding plate 23 that slides in a direction perpendicular to the sliding direction of the left and right folding plates 22; folding board 21
．． and a discharge button 69 that slides in a direction perpendicular to the sliding direction of the rear folding roller 22 and pushes out the tray T containing the packaged items toward the rear folding roller 24.

To summarize the operation of the film folding mechanism with the above structure,
As shown in FIG. 12(a), first, the items to be packaged, which are placed in a tray T by an elevator head (not shown), are formed by left and right folding plates 21, 22, a front folding plate 23, and a rear folding roller 24. 6. Push up the stretch film F stretched over the lower part of the opening. Next, move the left and right folding plates 21 and 22 straight toward the center of the opening, as shown in FIG. Fold it into the lower part of the T, and then move the front folding plate 23 straight toward the center of the opening as shown in the same figure (C).

Fold the front end of the stretch film F into the bottom of the tray T. Thereafter, the discharge button 69 is pushed out, and the rear end of the stretch film is folded into the lower part of the tray T by the rear folding roller 24.

In the film folding mechanism of the above structure.

Since the left and right folding plates 21, 22, the front folding plate 23, and the rear folding roller 24 all act at right angles to the packaged item, the stretch film is less likely to be wrinkled compared to conventional folding mechanisms, and the packaged item can be beautifully finished. becomes possible.

[Problem that the invention seeks to solve]

However, in the film folding mechanism of the above structure, as shown in FIG.
The width dimensions 11 on the front folding plate 23 side and Q2 on the rear folding roller 24 side are the same, and the opposing sides 21a and 22a of the left and right folding plates 21 and 22 are parallel. In addition, because the rear folding is performed at the time of carrying out, the rear folding roller 24y! is the standard for placing the packaged items. For this reason, it may be difficult to package trays of various sizes with different lengths and widths neatly for the following reasons.

In other words, trays for storing items to be packaged include small trays with extremely small vertical and horizontal dimensions such as trays for storing cod roe, elongated trays with small vertical dimensions and large horizontal dimensions for storing saury, etc., or trays with large horizontal and vertical dimensions for storing saury, etc. There are large trays, etc. Now, to explain the packaging using a small tray and a long and narrow tray as an example, the width dimension Q1. Q
The relationship between the folding end position of the left and right folding plates 21 and 22, in which the side sides 21a and 22a, which are equally opposite to each other, and the tray, is as shown in FIGS. 14(a) to 14(c).
Figure 14 (a) shows the case of a small tray, Figure 14 (b) shows the case of a long and narrow tray, Figure 14 (c) shows the case of a large tray), and Figure 14 (b) shows the case of a small tray. In the case of the elongated tray Tb, the folding dimension M for the tray Tb is as follows.
However, as shown in FIG. 14(b), the folding dimension is larger than that of the small tray Ta. As shown in FIG. 14(C), in the case of a large tray Tc with large vertical and horizontal dimensions, even if the folding dimensions are large, there is no particular problem in the packaging finish, but as shown in FIG. 14(b), the elongated tray Tb If the vertical width is small, as in the case of the front folding, the excess film portion on the front folding plate 23 side will be squeezed too much by the interval formed by the left and right folding plates 21 and 22.
As a result of this effect, many wrinkles are formed in the front central part of the packaged item, resulting in an unsatisfactory packaging finish.

The present invention has been made in view of the above points.

To provide a film folding mechanism for a packaging machine that allows the packaging to be neatly finished regardless of the size and shape of the tray.

[Means for solving problems]

In order to solve the above problems, the present invention provides a pair of left and right folding plates that are arranged opposite to each other at a predetermined position of a packaging machine and that slide in the left and right horizontal directions, and a pair of left and right folding plates that slide in the horizontal direction orthogonal to the sliding direction of the left and right folding plates. A sliding front folding board,
In a film folding mechanism of a packaging machine, the film folding mechanism of a packaging machine includes a rear folding member provided opposite to the folding plate and parallel to the sliding direction of the left and right folding plates,
The gap formed by the left and right folding plates facing each other was made larger on the front folding plate side and smaller on the rear folding member side, so that a relief portion was provided for the film on the front folding plate side.

[Effect]

By configuring the film folding mechanism as described above, when the left and right folding plates are moved straight toward the packaged object, the folding dimension of the film is smaller on the front folding plate side.
The rear folding member side becomes larger. As a result, the conventional phenomenon of over-squeezing the film on the front folding plate side is eliminated, resulting in a film folding mechanism that provides a neat packaging finish.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a diagram schematically showing a film folding mechanism according to the present invention.

In the same figure, left and right folding plates 21 are placed at predetermined positions on the packaging machine.
, 22, front folding plate 23 and rear folding roller 24
and the left gripper Gl on the front and rear sides.
G4. Center gripper G2°G5, right gripper G3.
The placement of G6 is based on the patent application filed earlier by the applicant in 1982.
-204744 and Japanese Patent Application No. 59-182466.

In this embodiment, as illustrated in the shape of the left and right folding plates 21 and 22, the gap formed by the left and right folding plates 21 and 22 facing each other is such that the predetermined length G3 portion on the rear folding roller 24 side is parallel and the front The distance on the folding plate 23 side is formed to be larger than the distance between the parallel portions. In other words, the dimension at on the front folding plate 23 side of the left and right folding plates 21, 22 is made smaller than the dimension Q2 of the parallel portion α3 on the rear folding roller 24 side to form a relief part S of the film F on the opposing sides 21a and 22a. . The length G3 of the parallel portion is approximately the same as the maximum vertical width of the tray to be packaged.

When the left and right folding plates 1 and 2 having the above shape are moved straight horizontally to the tray T and the film F is folded into the bottom of the tray T, the left and right folding plates 21 and 22 reach the positions shown by dotted lines. As shown in the figure, when the left and right folding is completed, the interval through which the film that is folded into the lower part of the tray T passes by the front folding plate 24, that is, the interval formed by the left and right folding plates 21 and 22, is Since the front part is large, the amount of front folding is small from this state. Therefore, even if the front folding plate 23 is moved straight toward the tray T from this state, the portion of the film F that is folded by the front folding plate 23 is not squeezed much, so that wrinkles do not increase and the packaging finish is neat.

In addition, by forming the relief portions S in the left and right folding plates 21 and 22 as described above, the timing at which the left and right folding plates 21 and 22 contact the film when folding the left and right films is different from that on the front folding plate 23 side and on the rear folding roller side. It is different on the 24th side. That is, the front folding plate 23 side is slow, and the rear folding roller 24 side is fast. Therefore, if the left and right front grippers Gl and G3 and the left and right rear grippers G4 and G6 are operated at the same timing, the tension of the film F may be different between the front and rear grippers, resulting in poor packaging results. Therefore, left and right rear grippers-G4. G
The tension state of the film F is adjusted by setting the opening timing of the gripper 6 earlier than the opening timing of the left and right front grippers Gl and G3. The structure and operation of the film folding mechanism will be explained below.

FIG. 2 is a plan view showing the overall structure of the packaging machine according to the present invention;
3 is a longitudinal sectional front view of the same (as seen from the direction of arrow B in FIG. 2), and FIG. 4 is a longitudinal sectional side view of the same (as seen from the direction of arrow B in FIG. 2).

The packaging machine includes a carry-in mechanism 1 that carries in an object to be packaged, a film feed-out transfer mechanism 2 that feeds out and transfers a stretch film, and a film feed-out transfer mechanism 2 that feeds out and transfers the stretch film, and transfers the packaged object carried in by the carry-in mechanism 1 into a film transferred by the film feed-out transfer mechanism 2. An elevator mechanism 3 that pushes up, a folding mechanism 4 that folds the left and right sides and front and back of the film placed over the packaged item.
, and a carry-out mechanism 5 for carrying out the folded and packaged articles by the fold-in mechanism 4. Each of the above mechanisms will be explained in detail below.

For convenience of explanation, the left side of FIG. 2 will hereinafter be referred to as the front side and the right side as the rear side.

At the entrance 11 provided in the center of the front of the machine frame 10,
A carry-in frame part 12 is provided, and a bushing conveyor 13 is further disposed within the carry-in frame part 12. Butsusha conveyor 13 is
It has a structure in which two bushings 13b are provided at predetermined locations on two endless chains 13a, and two sprockets 13c.

13c, the butcher conveyor 13 is driven, and one article to be packaged is carried in every 1/2 rotation of the endless chain 13b. A weighing device 14 is provided on the carry-in side of the butcher conveyor 13, and weighs the articles to be packaged to be carried in. A belt conveyor 15 is provided in front of the butcher conveyor 13 to convey the packaged articles carried in by the butcher conveyor 13 onto the elevator head 17 of the elevator mechanism 3. The belt conveyor 15 has six round rubber belts 15 between rollers 15a and 15b that are freely rotatable.
It has a structure in which c is stretched. The bumper conveyor 13 and the belt conveyor 15 constitute a loading machine W1.

The elevator mechanism 3 includes an elevator head 17, a mounting base 18 for mounting the elevator head 17, and a pair of arms 19 and 19 that support the mounting base 18. It is designed to move up and down at pre-set timings. The timing of this vertical movement is set by the cam shape of a cam mechanism, which will be described later, which is interposed in a mechanism that transmits the power of the electric motor 16 to the mounting table 18. Elevator head 17 is connected to bumper conveyor 13 and belt conveyor 15.
The packaged items carried in are pushed up to the folding mechanism 4. Therefore, the lowering end position of the vertically moving elevator head 17 is set to a position that is almost flush with the conveying surface of the belt conveyor 15, and the ascending end position is set to a position where the left and right folding plates 21 (described later) forming the folding mechanism 4, 22 and the front folding plate 23.

The elevator head 17 and the mounting base 18 are shown in FIG.
As shown in FIG. 4, a slit-shaped block 17-
1 to 17-5, and when the elevator head 17 moves up and down, the elevator head 17 and the mounting plate 18 are attached to the round rubber belt 15C of the belt conveyor 15.
I try not to let them touch each other. Further, the central block 17-3 of the elevator head 17 is further divided into a plurality of small blocks 17-3a, and each block 17-3 is further divided into a plurality of small blocks 17-3a.
Although 3a is normally kept upright by a biasing means (not shown), it is tilted to the right in FIG. 2 by a force from the left in FIG. Also, blocks 17-1 and 17- above block 17-3a from the center
2 is tilted downward in the figure by a force from above in Figure 2, and the lower blocks 17-4 and 17-5 are tilted upward by a force from below in Figure 2. It is composed of This is to allow the folding mechanism to perform the folding operation without any trouble, as will be described later.

In addition, in FIGS. 2 and 3, 20 is a positioning plate provided at the rear of the elevator head 17, and is used to position the conveyed object carried in by the belt conveyor 15 with reference to the rear end. be.

The film feed-out transfer mechanism 2 that feeds out and transfers the stretch film feeds out the stretch film from a stretch film roll 34, 34' provided on the right side of the packaging machine, and transfers the stretch film while holding both ends. It is a mechanism. Stretch film roll 34, 34
' is a roll wound with stretch film having different widths, and is supported by a pair of support rollers 36, 36' and support rollers 37, 37', and is configured so that it can be used selectively depending on the size of the item to be packaged. There is.

In the example shown in FIG. 4, the upper stretch film roll 34 is used. The stretch film unwound from the stretch film roll 34 is pulled out so as to be wound around the right support roller 36', and passed through the end detection roller 38 to the upper and lower unwinding belts 39.
The stretch film sandwiched between belts 39, 39' and 40' is sandwiched between belts 39, 39' and 40'.
It is unrolled by turning 40' and reaches its tip. Thereafter, one end of the stretch film is held between a group of clippers 41, 41' of a chain conveyor 57, which will be described later, and a round rubber belt 42, 42' made of rubber material, and the stretch film is held in a predetermined range necessary for wrapping the item to be packaged. The length is further extended. When the stretch film is unrolled for a predetermined length, the cutter 43 is pushed up by the cutter drive device 44 and the stretch film is cut. After cutting, the stretch film is transported to a predetermined position above the elevator head 17, that is, a position where the center 1 of the cut stretch film coincides with the center of the elevator head 17, and then stopped and waited there. The clippers 41, 41' group and the round rubber belts 42, 42' are connected to the left and right folding plates 21.2 as shown in FIGS. 2 and 4.
2, the opening 25 formed by the front folding plate 23 and the rear folding roller 24, and the descending end of the elevator head 17, when the packaging machine is viewed from above.

They are arranged opposite to each other so as to sandwich the opening 25 in the front and rear.

The film feeding and transporting mechanism will be explained in more detail with reference to FIGS. 5 and 6. A pair of adjustment screws 45.46 are rotatably provided opposite to each other at predetermined positions on the machine frame 1o.
Hypoid gears 47.
48 is fixed. Further, a rotating shaft 49 is disposed along the rear surface of the one-machine frame 10, and a hypoid gear 50.51 that meshes with the hypoid gear 47.48 is fixed at a predetermined position of the rotating shaft 49.

A handle 52 is attached to the right end of the rotating shaft 49 on the outside of the machine frame 10, and by rotating this handle 52, the adjustment screws 45 and 46 can be rotated via the rotating shaft 49. can. The thread pitch of the adjustment screws 45 and 46 is dense on the upper side in FIG. 5 and sparse on the lower side, and they have opposite threads. Adjustment blocks 53 to 56 are provided near both ends of the adjustment screws 45 and 46, and are provided with nuts that engage with the respective threaded portions. A chain conveyor 57 is arranged using the adjustment blocks 53 and 55 on the rear side as a base, and the adjustment block 54 on the front side
．． A chain conveyor 57' is arranged using 56 as a base. Each chain conveyor 57.57' has a central axis x-x
' The stretch film is disposed in a widening shape toward the direction of transport of the stretch film. As a result, the stretch film is strongly pulled as it is transported. Since the chain conveyors 57 and 57' have a nearly symmetrical structure, the structure of the chain conveyor 57 will be explained below. As shown in FIG. 6, the adjustment block 5
3 is provided with a support member 58. The adjustment block 55 is provided with a support member 59. The mounting support member 58, 59 has a plurality of screws 58a for mounting the board 60.
, 59B, the mounting is fixed. Mounted on board 6
Sprockets 61 and 61' are rotatably disposed at both ends of the frame, and an endless chain 57a is stretched between the sprockets 61 and 61'. As shown in FIG. 7, an endless round rubber belt 42 having a circular cross section is provided around the outer periphery of the chain 57a. A plurality of grippers 41 are attached to the outside of the chain 57a at predetermined intervals so as to be rotatable around a shaft 41a. A semicircular recess 41b having a shape that fits into the round rubber belt 42 is formed at the tip of the gripper 41. For installation, a support plate 62 is attached to the upper part of the board 6o over a predetermined range with screws 63, and a protrusion 62a integrally formed on the support plate 62 is fitted into a central recess of the chain 57a. In addition to guiding and supporting the gripper 41, another integrally formed protrusion 62b engages with an engaging hook 64a integrally formed on the plate 64, and the gripper 41 is attached to the plate 64. 64 is guided and supported.

Three movable guide members 65 to 67 and 65' to 67' on the left side, center, and right side are provided at predetermined positions outside the chain conveyor 57, 57'. Each movable guide member 65-67.65'-67' has a similar structure, and each movable guide member 65-67.65'-67'
' are engaged with the rear ends of three grippers 41, respectively.

For example, as shown in FIG. 7, the three grippers 41 rotate simultaneously about the shaft 41a by the operation of the solenoid 68, and the recesses 41b at their tips are released from the round rubber belt 42, as shown by the two-dot chain line.

Further, when the solenoid 68 is inactivated, the tip recesses 41b of the three grippers 41 are pressed against the round rubber belt 42. The tip recess 41b of the gripper 41 and the round rubber belt 42
The stretch film is sandwiched between the two and transported.

The folding mechanism 4 includes a left folding plate 2 as shown in FIG.
1. Right folding plate 22. It has a front folding plate 23 and a rear folding roller 24, and these left and right folding plates 21.
22, the front folding plate 23, and the rear folding roller 24 form an opening 25 through which the packaged object pushed up by the elevator head 17 passes. The left folding plate 21 and the right folding plate 22 are flat plates that fold the left and right sides of the film covering the object to be packaged, and as shown in the shape of the left and right folding plates 21 and 22 shown in FIG.
The gap formed by the left and right folding plates 21 and 22 facing each other is formed so that a predetermined length 123 portion on the rear folding roller 24 side is parallel and the gap on the front folding plate 23 side is larger than the gap between the parallel portions. Parallel guide bars 26, 26 facing the opening 25 are provided on both sides of the upper part of the machine frame 10.
', each guide bar 26.26.26', 26
', the left folding plate 21 and the right folding plate 22 are installed at the bottom of the sliding members 27, 27' and 27', respectively.
Install. Pivot shafts 118c and 118C' are provided near the left and right folding plates 21 and 22 (see FIG. 8), and each pivot shaft 118c and 118c' has a rotating frame 118b and 118b.
' is installed so that it can rotate freely. The rotating frames 118b, 118b
The rear end of ' is rotatably connected to the left and right folding plates 21 and 22. The rotating frames 118b and 118b' are rotatably linked to a link 118, and the link 118 causes the left and right folding plates 21 and the right folding plate 22 to simultaneously advance in opposite directions, that is, toward or away from the center of the opening 25. It's starting to move backwards. The front folding plate 23 is a flat plate having a front folding roller 23a freely rotatable on the side facing the opening 25, as shown in FIG. On both sides of the machine frame 10 of the opening 25, side guide rails 28,
28' are arranged respectively, and the respective side guide rails 28, 28'
the first sliding member 29,29' and the second sliding member 3
0.30'' is attached to each sliding member 29 and 29' by crossing the folding plate 23. One sliding member 29 is linked via the first drive member 3 and the crank mechanism 33, and the front The folding plate 23 is moved forward toward the rear folding roller 24 or retreated from the rear folding roller 24.

The crank mechanism 33 includes a rotating frame 33a fixed to the first drive shaft 31 and a rotating frame 33b fixed to the sliding member 29.

They are rotatably linked via a pivot 33c.

A pusher 69 is attached to the sliding member 30, 30', and is moved forward toward the rear folding roller 24 or from the rear folding opening similarly to the front folding plate 23 by the second drive shaft 31' and crank mechanism 33'. It is designed to retreat from 24.

The carry-out mechanism 5 includes a pusher 69 for pushing out the packaged object in which the left and right stretch films and front stretch films have been folded by the folding mechanism 4, a width shifting slider 70 for placing and width-aligning the packaged object pushed out by the pusher 69; It is composed of a heat belt 71 and the like. The object to be packaged is pressed by the pusher 69, and the subsequent stretch film is folded by the rear folding roller 24.

The packaged item is placed on the heat belt 71, and after the film is welded and the label is automatically pasted, it is carried outside.6 Next, a drive system for driving each part of the packaged item will be explained.

FIG. 8 is a system diagram showing the drive system of the packaging machine. In FIG. A V pulley 82 fixed to the input rotating shaft of the reducer 81 is connected to the V pulley 82.
Power is transmitted via the belt 83. The speed reducer 81
A slit disk 84 having a structure to be described later is attached to one of the output rotating shafts.
is fixed, and a sensor 85 detects the movement of the slit formed in this slit disk 84 to obtain a timing signal for power control of the packaging machine. A sprocket 86 is fixed to the other output rotating shaft of the reducer 81, and power is transmitted from the sprocket 86 via a chain 89 to a sprocket 88 fixed to a main drive shaft 87 of the packaging machine. The main drive shaft 87 has sprockets 90 and 91.
．． 92 is fixed, and furthermore, an elevator vertical movement cam 93 is fixed to one end. The sprocket 92 is
Power is transmitted to the sprocket 13c of the butt conveyor 13 via the chain 94, and the sprocket 91 is connected to the round rubber belt 13c of the belt conveyor 15 via the chain 95.
The power is transmitted to a sprocket 96 fixed to the rotating shaft of the roller 15b that powers the roller 15b. The elevator vertical movement cam 93 applies vertical movement power to the levers 19 and 19 via a drive rod 98 that is driven vertically about a fulcrum 97, thereby causing the elevator head 17 to move up and down. Also, sprocket 90
The chain is 99.100 on sprockets 103 to 106.
, 101, 102 to transmit power. The sprocket 103 transmits power to the electromagnetic clutch brake 108 via a 90-degree bevel gear 107, and from the electromagnetic clutch brake 108 to the sprocket 1 fixed to the drive shaft 110 of the film transport and supply mechanism 2 via a chain 109.
11. As a result, the feed belts 39, 39', 4 that feed and feed the stretch film
0.40' and a round rubber belt 42.42' that pinches and transports both ends of the stretch film.

Chain conveyors 57, 57', etc., to which grippers 41, 41' are attached at predetermined intervals, rotate by receiving driving force.

The sprocket 104 transmits power to an electromagnetic clutch brake 113 via a 90 degree bevel gear 112, and the electromagnetic clutch brake 113 transmits power to the front folding plate 23. The sprocket 105 is a 90 degree bevel gear 114
Power is transmitted to the electromagnetic clutch brake 115 via the electromagnetic clutch brake 115. The electromagnetic clutch brake 115 has a discharge button 69.
transmit power to. In addition, the sprocket 106 transmits power to an electromagnetic clutch brake 117 via a 90 degree bevel gear 116, and the electromagnetic clutch brake 117 transmits a driving force to the left and right folding plates 21, 22 to move straight toward the center of the opening 25. The driving force for retreating from the shaft is transmitted in conjunction with the sliding member 27, 27' and the crank mechanism 118.

As shown above, the drive system of the packaging machine is connected to the electromagnetic clutch brake 1.
08, 113, 115, and 117, the clutch release button on the control panel can be used to stop the packaging machine in an emergency due to an accident such as overturning or clogging of the packaged items. By turning on the
Electromagnetic clutch brake 108, 113, 115, 117
If you release each of them, the film transport and supply mechanism 2. Each member constituting the folding mechanism 4 and the unloading mechanism 5 can be moved individually by hand, making it easier to remove packages that have fallen or become jammed, and the time required to restart operation is extremely shortened. .

In the above embodiment, the power of the electric motor 16 is transferred to the electromagnetic clutch brakes 108, 113, 1 as independent driving means.
15, 117, but these electric motors 16 and respective electromagnetic clutches and brakes 108, 1
It is also possible to automatically move each member by replacing the motors 13, 115, and 117 with electric motors capable of forward and reverse rotation and appropriately selecting the direction of rotation.

The above is a description of the mechanical structure of the packaging machine and its drive system. The control device for the packaging machine will be explained below.

FIG. 10 is a block diagram showing the configuration of the folding control device of the packaging machine. In the figure, solid lines indicate electrically transmitted parts, and dotted lines indicate mechanically transmitted parts. The control device is a central processing bag [12o, operation display panel section 121-
1 storage unit 123. It is composed of an input/output control circuit 124, a drive control circuit 125, and a main timing detection section 126.

The operation display panel section 121 includes an operation section 121a that inputs operation commands and control data to the central processing unit 120, and a display section 121b that performs various displays based on signals from the central processing unit 120.

The storage unit 123 includes a read-only memory (ROM), 12
3a and random access memory (RAM) 123b
It consists of

The input/output control circuit 124 is an interface control circuit that outputs a signal from the central processing unit 12α to the drive control unit 125 and inputs a timing signal from the timing detection unit 126 to the central processing unit 120.

The drive control circuit 125 includes drive circuits 125a to 125i. The drive circuit 125a is a circuit that drives the main power unit 129 composed of the electric motor 16 and the speed reducer 81, the drive circuit 125b is a circuit that excites the electromagnetic clutch 108 that drives the film feeding and transporting mechanism 2, and the drive circuit 125C is a circuit that drives the left and right folding The drive circuit 125d is a circuit that excites the electromagnetic clutch 117 that drives the plates 21 and 22. The drive circuit 125d is a circuit that excites the electromagnetic clutch 113 that excites the front folding plate 23. The drive circuit 125e is a circuit that excites the electromagnetic clutch that drives the discharge button 69. , the drive circuit 125f drives the left and right front movable guide members 65' and 67', and the gripper 41 (left and right front gripper Gl in FIG. 1) that engages with the movable guide parts 65' and 67'.

G3), the drive circuit 125g drives the central movable guide member 66' to open the movable guide member 66.
125h is a circuit for releasing the gripper 41 (center front gripper G2 in FIG. 1) engaged with the rear center movable guide member 66, and a circuit 125h is a circuit for releasing the gripper 41 (center front gripper G2 in FIG. The driving circuit 1251 is a circuit for opening the central rear gripper (G5) of the left and right rear movable guide member 65.
67 and engages the movable guide member 65.67 (left and right rear grippers G4.G in FIG. 1).
6) is a circuit that opens.

The main timing detection unit 126 is a part that detects a signal from a timing signal generator that is fixed to the rotating shaft of the reducer 81 shown in FIG. , the left and right folding plates 21, 22, the front folding plate 23, etc. of the packaging machine.

The central processing unit 120 receives the timing signal from the timing detection section 126 and the ROM 1 of the storage section 123, which will be described later.
23a, each drive circuit 1 through the input/output control circuit 124 based on the data stored in the operation timing table of
25a to 1251 to drive each part of the folding mechanism at predetermined timing. Note that 128 is a detection sensor that detects the size of the object to be packaged.

In the folding mechanism 4, by forming the relief portions S in the left and right folding plates 21 and 22 as described above, the timing at which the left and right folding plates 21 and 22 contact the film is delayed on the front folding plate 23 side, and the rear folding roller 24
The side gets faster. Therefore, the central processing unit 120
123a, the left and right rear grippers G4. A signal is sent to the drive circuits 125f and 125i so that the opening timing of G6 is earlier than the opening timing of the left and right front grippers Gl and G3, and the left and right front movable guide members 65', 67' and the left and right rear movable guide members 65. 67.

FIG. 15 is a mechanical chart showing an example of the operation of each part of the folding mechanism. In the figure, the slit disk 8
It is assumed that one pulse signal is outputted from the main timing detection section 126 every time 4 rotates 5 degrees.

In the figure, the elevator head 17 and the front folding plate operate at the timing shown by the solid lines in (a) and (c) of the figure. In addition, the left and right folding plates 21, 22 and the ejection button 69 are indicated by the solid lines shown in (b) and (d), or by the dotted lines, depending on the tray type and film cut length.
As shown, it works.

In the case of a standard tray, the left and right front grippers Gl and G3 open at count 20 and close at count 24, as shown by the solid line in FIG. 11(e). On the other hand, the left and right rippers G4 and G6 open at count 18 and close at count 22. In other words, left, right, front and rear grippers G
The opening timing of G3 is determined by the left and right rear grippers G4. G
It is 2 counts earlier than the opening timing of 6, that is, 10 degrees earlier for the slit disk 84. In addition, left and right front grippers Gl, G3 and left and right rear grippers G4. G6
It is possible to set five opening timings, i.e., A, B, H, and E, shown in dotted lines, centering around the timing shown in the solid line, respectively, and the setting data from the operation section 121a and the size detection of the packaged object described above can be set. Based on the detection data from the section 128, the central processing unit 120 adjusts the tension of the film according to the type of tray and the film cut length.

In addition, the center front gripper G2 is normally used as shown in FIG. 11 (
As shown by the solid line in g), it opens at count 26 and closes at count 30, and in order to adjust the tension of the film, there are openings before and after it as shown by the dotted line.
It is possible to set five different opening timings.

The central rear gripper-G5 is the 111ii! It opens at count 34 and closes at count 40 as shown in (f) of l. At this time, at the same timing, the left and right grippers G4. G6
open and close. This operation of the left and right grippers 04 and G6 is a so-called safety measure to ensure complete release of the film.

〔Effect of the invention〕

As explained above, in the folding mechanism according to the present invention, the shape of the left and right folding plates is such that the gap formed when the left and right folding plates face each other is smaller on the front folding plate side and on the rear folding member side. Even with a tray whose width is extremely large compared to its length, the amount of squeezing of the film on the front folding plate side during front folding is reduced.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the structure of the film folding mechanism according to the present invention, FIGS. 2 to 4 are diagrams showing the structure of the packaging machine, FIG. 2 is a plan view, and FIG. Figure 4 is a vertical side view (view seen from the direction of arrow B in Figure 2), Figures 5 and 6 are the film feeding and transporting mechanism of the packaging machine. Fig. 5 is a plan view, Fig. 6 is a side view, Fig. 7 is a sectional view of the gripper mechanism, Fig. 8 is a system diagram showing the drive system of the packaging machine, and Fig. 9 is a slit diagram. Figure 10 is a block diagram showing the configuration of the control device for the folding mechanism, Figure 11 is a mechanical chart showing the movement of the folding mechanism, and Figure 12 is the packaging previously filed by the applicant. FIG. 13 is a diagram for explaining the outline of the folding mechanism of the machine and its operation, and FIG. 13 is a diagram showing the outline of the folding part. FIGS. 14(a)', (b), and (c) are views showing the relationship between the tray and the left and right folding plates, respectively. In the figure, ■... Carry-in mechanism, 2... Film feeding mechanism transfer mechanism, 3... Elevator mechanism, 4... Folding mechanism, 5... Carrying out mechanism, 21... Left and right folding plates, 2
2...Left and right folding plates, 23...Front folding plates, 2
4... Rear folding roller.

Claims (1)

[Claims] A pair of left and right folding plates that are arranged to face each other at a predetermined position of a packaging machine and slide in the left and right horizontal directions, a front folding plate that slides in a horizontal direction perpendicular to the sliding direction of the left and right folding plates, and the front folding plates. In a film folding mechanism of a packaging machine, the film folding mechanism of a packaging machine is provided with a rear folding member provided facing each other and parallel to the sliding direction of the left and right folding plates, and the shape of the left and right folding plates is determined by the gap formed by the left and right folding plates facing each other. A film folding mechanism for a packaging machine, characterized in that the film folding mechanism is formed such that the front folding plate side is large and the rear folding member side is small.