JPS6159234B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a printing device for a film packaging machine.

Conventionally, for example, in a three-sided seal film packaging machine, the packaging film is run at a constant speed, the object to be packaged is wrapped, and a wrapping bag is formed by welding between a vertical sealer and a horizontal sealer, and the packaging film is moved at a constant speed. A printing head is brought into pressure contact with a packaging film via a printable printing tape by thermocompression bonding to print information such as the date of manufacture.

In this conventional printing means, an electromagnetic clutch is interposed between a drive shaft rotating at a constant high speed and a printing head, and a micro switch is made to cooperate with a cam that is rotated by the rotation of a horizontal sealer.
A signal from the microswitch connects the electromagnetic clutch in synchronization with the horizontal sealer's melting process, and when the printing head presses against the packaging film to be wrapped and rotates once, the electromagnetic clutch is released and the electromagnetic clutch is released. I'm trying to apply the brakes and prepare for the next one.

In such printing means, the feeding speed of the film and the circumferential speed of the printing head when it comes into pressure contact with the film are different, so if the former speed is fast, the film may be broken by applying a brake, or the film may be torn. On the other hand, when the speed of the former is slow, there is a drawback that the print is scratched on the film and the print becomes unclear.

There is also a technique to overcome the above drawbacks by creating a certain amount of clearance between the output shaft from the electromagnetic clutch and the printing head via a tension spring.
However, this cannot accommodate the tolerance range when changing the film feed speed depending on the length of the packaged item, and if necessary, the rotational speed of the electromagnetic clutch must be adjusted to the speed of the printing head when it contacts the film. This method has the disadvantage that it is not suitable for high-speed operation because it has to be adapted to the print head, or it has to provide two or more print bodies depending on the circumference of the print head. Moreover, since an electromagnetic clutch or an electromagnetic brake is used, they wear out with use, resulting in inaccurate rotation and stopping, which also causes problems in that the timing of printing is out of order.

Furthermore, by moving the guide roller in the opposite direction to the forward direction of the continuous sheet material, the continuous sheet material sandwiched between the roller and the printing head stops only during the printing time, absorbing the amount of slack during the stopping time on the sheet material entry side. There is known a printing device in which the roller moves in the opposite direction as much as necessary to print, and then returns in a crescent motion for the next printing (Japanese Patent Application Laid-Open No. 40309/1983). However, with this printing device, tensile stress corresponding to the stop time during printing is generated in the sheet material on the feeding side, making it difficult to feed the film smoothly.
This method has the disadvantage that it results in "uneven" supply and that the seals are misaligned, making it difficult to cope with the problem, especially at high speeds.

The present invention was brought about as a result of intensive research to solve the above-mentioned difficulties, and preferred embodiments will be described in detail below with reference to the drawings.

In Figure 1a, a pair of parallel rollers 1
The packaging film 16 pulled out from the feed reel 14 placed on the rollers 20, 22, 24 passes through the printing head 38, rotates around the tension roller 18 whose surface is made of rubber, and moves the rollers 20, 22, 24 in a zigzag pattern. It turns around and travels to the former 26 at a constant speed. Note that 28 and 30 are a pair of parallel pressure rollers for pressing the film against the tension roller 18.

The object to be packaged is wrapped in the former 26 and a wrapping bag is prepared (see FIG. 1b). The film is driven forward by the catch roller 32, and the vertical seal is fused by the vertical sealer 34. A cylindrical film is formed, and a wrapping bag is formed for each packaging length by welding and welding using a horizontal sealer 36.

Accordingly, the speed change gear prepared in advance is replaced according to the size of the packaged object to change the speed change ratio, thereby changing the circumferential speeds of the catch roller 32 and the vertical sealer 34 arranged in parallel. Therefore, when the peripheral speeds of the catch roller 32 and the vertical sealer 34 are changed depending on the size of the packaged items, it is necessary to make the peripheral speed of the catch roller 32 and the peripheral speed of the horizontal sealer 36 constant during welding. be. Therefore, it is essential to provide a differential or transmission mechanism for achieving this constant speed. Since this mechanism is disclosed in Japanese Utility Model Application Publication No. 52-92184, detailed description thereof will be omitted here.

In this way, although the catch roller 32 and the vertical sealer 34 rotate at a constant speed with their circumferential speeds changed depending on the dimensions of the packaged item,
The speed of the horizontal sealer 36 is changed during fusing and welding so that the speed is constant with the circumferential speed, and normally it is driven at non-uniform speed rotation, however, it is rotated once for every length of the package.

Note that it is preferable that the tension roller 18 be driven at a peripheral speed slightly slower than the peripheral speeds of the catch roller 32 and the vertical sealer 34.

On the other hand, for each length of packaging to be created, the printing head 38 is attached to a printing tape 72 that can be printed by thermocompression bonding.
It is necessary to press it onto the packaging film 16 via a holder to print, for example, the date of manufacture.

According to a feature of the present invention, the circumferential speed of the horizontal sealer 36 driven under the conditions described above during welding is made equal to the circumferential speed of the printing head 38 when printing on the film.

Therefore, the rotation shaft 40 of the horizontal sealer 36 is driven synchronously with the input shaft 42 of the print head 38 by a chain 44 or the like. In this case, the ratio of the number of teeth on the sprockets rotating the chains on both shafts is 1:1.

Next, details of print head 38 will be described in detail with reference to FIG.

The input shaft 42 has an eccentric cam 60 attached thereto.
The other arm 50 is connected to the connecting rod 46 of the crank 44 through the support shaft 52 of the print head 38.
The arm 50
and the connecting rod 46 are connected by a pin 48. Further, the lower end portion of the rocking table 50' to which the support shaft 52 is rotatably pivoted is pivoted to a fixed shaft 56 fixed to the frame 54 (FIG. 7). For this reason,
The support shaft 52 changes to the fixed shaft 56 according to the rotation of the input shaft 42.
A reciprocating rocking motion is performed in the direction of arrow 58 using the fulcrum as the fulcrum.

Furthermore, a roller 62 is provided protrudingly on the arm 60 attached to the input shaft 42, and a slider crank 66 having a slider 64 driven by the roller is pivotally connected to the support shaft 52. Connecting bush 5 with pin 66' attached to support shaft 52
A spring 66'' is provided between the slider crank 66 and the connecting bush 52' to spring the connecting bush counterclockwise. Therefore, depending on the rotation of the input shaft 42, the support shaft 52
performs reciprocating rotational motion in the direction of arrow 68 about its axis. Note that the notch 52'' of the connecting bush 52' is designed to complete printing without damaging the packaging film even if the packaging film is pulled out beyond a certain level while the printing head 38 is pressing against the packaging film. Rotation correction is performed (Fig. 8).

As a result of these reciprocating movements, the support shaft 52 and the printed body 70 attached thereto perform a crescent movement relative to the film 16 in synchronization with the horizontal sealer, as shown in FIG.

The rotational shaft 40 of the horizontal sealer and the sprocket on which the chain 44 rotates on the input shaft 42 of the print head 38 have a tooth number ratio, that is, a rotation ratio of 1:1.
When the rollers 62 are in the state shown in FIG. 2, the distance from the center of the input shaft 42 to the center of the rollers is equal to the distance from the center of the rollers to the center of the support shaft 52. 36 rotating shafts 4
By making the distance from the center of 0 to the sealing surface 41 equal to the distance from the printing body 70 of the print head 38 to the center of its support shaft 52, the distance from the center of the printing head 38 to the center of the support shaft 52 is generally reduced depending on the size of the packaged item. The circumferential speed of the horizontal sealer 36, which rotates at a constant speed, during welding can be made to match the circumferential speed of the print head 38 at the printing position P (FIG. 3).

The printing tape 72 is stretched between the supply reel 74 and the take-up reel 76, and the tension bar 78 and guide bar 8 are stretched counterclockwise in FIG.
0 and 82, and the printing tape is sandwiched and fed between a feed roller 84 and a pressure roller 86 pressed by the feed roller 84. When feeding this printing tape, the arm 6 of the slider crank 66
6 is connected to the shaft 90 of the feed roller 84 via a crank 88 and a one-way clutch 92 provided on one of its arms 87 and 89, and the one-way clutch 92 swings the arm 89 in accordance with the rotation of the input shaft 42. The shaft 90 is rotated intermittently in one direction to advance the printing tape by the amount necessary for printing. Further, the take-up reel 76 rotates together with the feed roller 84 by the belt 94, and winds up the printing tape.

As shown in FIG. 4, the supply reel 74 is mounted on a support shaft 98 secured to a mounting base 54' attached to the frame 54 with screws 96. A substantially cylindrical member 100 is provided on the support shaft 98, and a felt material 104 is interposed between its sliding surface 102 and the mounting base 54'. A pressure expansion spring 106 is provided between the support shaft 98 and the member 100 to press the member 100 against the felt material 104. On the member 100 are collars 108, 10.
an annular groove 110 that can be expanded freely by 8′, 108″;
110', 110'' are formed, and O-rings 112, 112', 112'' are fitted into these grooves. These grooves accommodate nuts 114 that thread into member 100.
When screwed in, it becomes narrower and pushes the O-ring outward in the radial direction, tightening the core of the printing tape loaded on the reel 74, and the printing tape 72 is tightened by the felt material 104. The required amount is delivered while the brake is applied.

The support shaft 52 protrudes from the aperture 53 and connects to the print head 3.
8, and the print body 70 is attached to the print tape 72.
It is assembled so that it is located above.

Next, when installing the printing device in a predetermined position, as shown in FIG.
The attachment part 12 is attached to the sprocket part 116 rotated by
6 and screwing the mounting screw portion 118 into the bolt screw portion 120 pivotally attached to the mounting portion 126. By moving the screw portion 118 forward and backward, the angle of the printing device, that is, the printing head 38 can be changed and the pressure with which the printing body 70 is pressed against the film 16 can be adjusted. After adjustment, it is fixed with a nut 122. Furthermore, by making the input shaft 42 slidable relative to the sprocket portion and the mounting portion 126 movable along the shaft 124, the printed body 70 can be moved in the lateral direction of the packaging film 16. Printing can be performed at any position in the horizontal direction. After adjusting this movement, the mounting portion 126 is fixed to the shaft 124 with a bolt (not shown).

In addition, in FIG. 2, 128 is the printing tape 7.
2 on the packaging film 16 by thermocompression bonding.

As mentioned above, in the present invention, the packaging film 1 fed out from the feeding reel 14 (FIG. 1)
6, after passing through the print head 38, the rollers 20, 22, 24 are swung from the tension roller 18 in a zigzag manner to the sealers 34, 36 (FIG. 6). In the illustrated embodiment,
The roller 20 is made movable so as to vary the process length of the packaging film up to the sealer.
That is, a handle 132 is provided on the frame 130,
By rotating this, the bevel gear 134,
136 rotates a screw bar 138 extending along the frame, and a screw piece 140 fixed to the roller 20 is screwed into this bar. Although a plurality of rollers are used in the illustrated embodiment,
Even if the film is rotated and moved around only one roller, the intended purpose is achieved.

After the packaging film passes through the printing head, the roller is rotated to reach the sealer, and since this roller is made movable, the process length of the packaging film to the sealer becomes variable.
As a result, the printing head can print on the packaging film at any position on the packaging bag to be formed in the longitudinal direction (that is, in the film feeding direction).

As is clear from the above embodiments, according to the present invention, the circumferential speed of the horizontal sealer, which moves at variable speeds depending on the dimensions of the packaged object, during welding can be made to match the circumferential speed of the printing head at the printing position. Because I can,
There is no longer any risk of tearing the packaging film through the printing tape or scratching on the film, resulting in unclear prints, as in the past, and it is possible to handle high speeds.

In addition, by driving the printing head in synchronization with the sealer so as to make a crescent movement with respect to the packaging film, the head contacts the printing tape and the packaging film during the forward pass during printing, and contacts the printing tape and the packaging film during the return pass. Since it is possible to escape and return without touching the print head, it is possible to give an ideal movement, and since no rotational movement is given to the print head, the space factor of the printing device is significantly improved, and the printing tape can be wrapped easily. It is also extremely easy to supply heating power for thermocompression bonding to the film.

The printing device of the film packaging machine of the present invention has a mechanism that generates a crescent movement in conjunction with a horizontal sealer drive unit that is driven in synchronization with the advancing continuous sheet material without changing the flow of the continuous sheet material, and the printing head After printing while moving in synchronization with the forward direction of the continuous sheet material, the head leaves and returns to its original position for the next printing. That is, an excellent effect is brought about in that printing can be performed without stopping the flow of the continuous sheet material during the printing process and without generating unnecessary tension.

In addition, after the packaging film passes through the printing head, a roller is rotated to reach the sealer, and since this roller is made movable, the process length of the packaging film to the sealer becomes variable, and if necessary, printing Printing on the packaging film by the head can be done at a desired position in the vertical direction on the wrapping bag to be formed, which greatly simplifies the actual positioning operation, and its value is extremely large. It is.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a film packaging machine according to the present invention, Fig. 2 is an exploded perspective view of a printing device used in the packaging machine shown in Fig. 1, and Fig. 3 is a movement of the printing head of the printing device shown in Fig. 2. FIG. 4 is a cross-sectional view of the printing tape supply reel of the printing device shown in FIG.
Fig. 5 is a perspective view showing a device for attaching the printing device shown in Fig. 2 to the main body, and Fig. 6 shows adjusting the printing position when printing on the packaging film by the printing device shown in Fig. 2. 7 and 8 are explanatory diagrams of the portions of the printing device shown in FIG. 2 that perform reciprocating swinging motion and reciprocating rotational motion, respectively. 14... Packaging film feed reel, 16...
Packaging film, 20...Roller, 36...Horizontal sealer, 38...Printing head, 40...Sealer rotation shaft, 42...Input shaft, 44...Crank, 5
2... Print head spindle, 62... Roller, 64...
...Slider, 66...Slider crank, 72...
... Printing tape, 74 ... Supply reel, 76 ... Take-up reel, 98 ... Support shaft, 110, 110',
110″...Annular groove, 112, 112′, 112″
...O-ring.

Claims (1)

[Claims] 1. Wrapping the object to be packaged in a packaging film running at a constant speed, forming a wrapping bag by melting and welding with a sealer, and printing a printing head for each wrapping length via a printing tape. In a printing device for a film packaging machine that prints by pressing onto a packaging film, an input shaft that is synchronously driven by the rotating shaft of the sealer swings back and forth to the support shaft of the printing head via an eccentric cam and a crank. motion and reciprocating rotational motion from the input shaft to the support shaft via a slider crank and a roller driven in the slider, and a rotation ratio of the rotation shaft of the sealer and the input shaft of the print head to 1. 1, the distance from the center of the input shaft to the center of the roller is equal to the distance from the center of the roller to the center of the support shaft, and the distance from the center of the rotation axis of the sealer to its sealing surface. and a printing device for a film packaging machine, characterized in that the distances from the printing body of the printing head to the center of its support shaft are equal. 2. A patent claim in which, after the packaging film fed out from the feeding reel passes through a printing head, a roller is rotated to reach a sealer, and the roller is movable so as to vary the process length of the packaging film leading to the sealer. A printing device for a film packaging machine according to item 1.