JPH03213330A - Independently driven sealing device in bag-making machine or the like - Google Patents

Abstract

PURPOSE:To rotate a sealing roller at a necessary time only for a necessary period by controlling the sealing roller with the controlling device of a driver so that the timing of turning start-up is made the best and also controlling the turning period at the necessary lower limit. CONSTITUTION:A servomotor 22 is utilized as the driving source of a sealing roller 2. This sealing roller 2 is joined to the servomotor 22 directly or by a transmission gear such as a timing belt. On the other hand, the turning state of the draw rollers 5 is controlled by a detection signal detected by a detector 21 (encoder, etc.) directly interlocked therewith. Further the said turning state is controlled by a signal sent from the detector 21 which shows the timing of basic rotation of a machine joined to a basic rotation axis 25 performing one rotation for one cycle of the machine and a signal for showing the feed length of a film. A controlling device 20 performs rotational control of the servomotor 22 by a controlling signal. Thereby rotation of the sealing roller 2 is not allowed to coincide with rotation of the draw rollers 5. Control is enabled for turning in the optimum conditions by the material and the shape of the film. Operation in an ideal state is enabled.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a sealing device for bags, sheets, etc., used in bag-making machines, etc., which manufactures bags by sealing half-folded sheets or the like.

(Prior Art) A conventional bag making machine has a configuration as shown schematically in FIG.

First, this configuration and operation will be explained. The raw film 16 unwound from the raw film roll 8 via the guide roll 17 is placed in the triangular plate holder 1 of the half-folding section 14.
5 in the transport direction to form a half-folded film 4. On the lower side of the figure, the right side of the two-dot chain line shows a front view as seen from the transport direction of the half-folded film 4, and the left side shows a side view similarly seen from the direction perpendicular to the transport direction. The half-folded film 4 is continuously fed to the dancer roller 12 by a web drive roller 13.13.

The half-folded film 4 that has passed through the dancer roller 12 is intermittently transported by a draw roller 5.5 and supplied to the sealing device 1.

As shown in FIG. 5, the sealing device 1 includes a draw roller 5.
．． A sealing roller 2 is supported on the underside of the half-folded film 4 that is being fed while being pinched by a roller 5, and a sealing roller 2 is pivotally supported in a direction perpendicular to the transport direction. It consists of a sealer 3 which is movably held. This sealing roller 2
The surface of the roller is made of rubber, and a Teflon cloth is wrapped or pasted thereon, and as shown in FIG. 6, it has a structure in which it rotates synchronously with the draw roller 5 by a gear device 19 or the like.

Since the operation of this sealing device 1 is closely related to the present invention, it will be explained in particular detail. Figure 7 is an explanatory diagram of the seal operation.
(a) The diagram shows sealing roller 2 and draw roller 5
．． When the film 5 stops, the sealer 3 descends and presses the half-folded film 4 against the sealing roller 2. Sealer 3 has a heater sealed inside and heats PE, CP.
A half-folded film 4 made of thermally weldable plastic such as P, DPP, etc. can be welded and cut at the same time. In the figure, just before the sealer 3 separates from the sealing roller 2, the big-off roller 7 comes down and is about to grab the bag 10 in front. (b) The figure shows that after the sealer 3 rises and leaves the half-folded film 4 after welding is completed, the sealing roller 2 and the draw roller 5.
5 starts rotating and sends out the half-folded film 4 whose tip is sealed. In this case, the sealing roller 2 is interlocked with the gear device 19 or the like so that the circumferential speed of the sealing roller 2 is approximately 3 to 10% faster than the circumferential speed of the draw roller 5. However, if the circumferential speeds of the draw roller 5 and the sealing roller 2 are equal, the tip 10' of the sealed bag 10 will stick to the sealing roller 2 as shown in the figure, and the subsequent half-folded film 4 will be pulled by the sealing roller. It may involve 2. (c) In the figure, after the rotation starts, the circumferential speed of the sealing roller 2 is faster than the circumferential speed of the draw roller 5, so if the welding point of the half-folded film 4 (the tip 10' of the half-folded film 4) is on the sealing roller Even if it is attached to the sealing roller 2, it is separated from the sealing roller 2 and is transferred toward the stacker conveyor 6. (d) The figure shows the above half-folded film 4.
This figure shows the state in which the leading end 10' of the stacker conveyor 6 is completely placed on top of the stacker conveyor 6. After this, again (a)
, the rear end of the bag 10 (the tip 1 of the next bag 10
At the same time that the bag 10 (same as 0゛) is sealed, the pick-off roller 7 descends to grip the leading tip B10° of the previously sealed bag 10 with the stacker conveyor 6 and pull it away from the sealing device 1, as shown in Figure 4. Transfer to corrugator 8. The bags 10 that have passed through the corrugator 8 are slowed down by a slowdown device 9, and are transferred to a bag aligning device 11 by flying through the air as stacked bags 10''.

Incidentally, FIG. 8 shows an example of a sealing device for a narrow bag, and in this case, since the transfer distance between welding points is short, the diameter of the sealing roller 2 is also inevitably small.

As a result, when the sealing roller 2 is pressed from above by the sealer 3, it may become curved. In order to prevent this, a large diameter backup roller 24 is brought into contact with the lower side of the sealing roller 2 to prevent the sealing roller 2 from bending. This ladle draw roller 5 and sealing roller 2
In order to align the rotational directions of the gears, the gear device 19 must have one more stage of gears.

Also, in order to omit the gear device 19, there is a device that is provided with a fixed sealer receiver instead of the sealing roller 2, but in this case, the sealer 3 always comes into contact with the same place, which may cause dents or burn damage. This is not desirable.

(Problem to be achieved by the invention) Since the sealing device 1 provided with the above-mentioned sealing roller 2 is mechanically interlocked with the draw roller 5 in the previous stage and the gear device 19, the sealing roller 2 does not rotate even during unnecessary periods. Therefore, it is not possible to set the rotation period that requires rotation.

Further, it is also impossible to start the rotation before the draw roller 5 starts rotating.

An object of the present invention is to solve the above-mentioned problems and provide a sealing device having a sealing roller that can be rotated at a necessary time and for a necessary period.

(Means for achieving the objective) In order to achieve the above-mentioned objective, after the half-folded film 4 etc. folded along the center line is continuously supplied, it is converted to intermittent transport by the draw roller 5.5. In a bag-making machine that seals the bag after the film has been folded, the sealing device 1 includes a sealer 3 provided above the half-folded film 4, etc. and movable up and down, and a sealer 3 located below the half-folded film 4, etc., at a position opposite to the sealer 3. The provided sealing roller 2 and this sealing roller 2
and a drive device 23 for driving the drive device 23.
consists of a servo motor 22 that drives the sealing roller 2, a detector 21 that detects the rotational state of the draw roller 5, and a control device 20 that controls the drive of the servo motor 22 based on a detection signal from the detector 21. It is something.

(Function) As described above, the sealing roller is controlled by the control device 20 of the drive device 23 to optimize the timing of the start of rotation and to minimize the rotation period (phase angle during rotation). control.

Furthermore, the speed curve, acceleration curve, etc. that determine the start-up state of rotation can be selected to obtain the best effect.

The servo motor 22 used in the drive device 23 can also be made smaller, and the backup roller 24, which has a large rotational inertia torque and is used for making narrow bags (those with small film feed), can be rotated with a small amount of rotation. This makes it easy to extend the life of the sealing roller 2.

(Example) FIG. 1 is a block diagram of a single drive device 23 of the present invention.

The sealing roller 2 uses a servo motor 2 as a driving source.
2, and can be connected directly or by a transmission device such as a timing belt. On the other hand, the rotational state of the draw roller 5 is determined by a detection signal detected by a detector 21 (such as an encoder) that is directly linked to the draw roller 5, or by a detection signal detected by a detector 21 (such as an encoder) that is connected to the basic rotating shaft 25 that rotates once per cycle of the machine. The control device 20 operates the servo motor 2 in response to a signal from the detector 21 (encoder, etc.) indicating the basic rotation timing of the machine and a signal indicating the film feed length.
2 rotation control is performed.

In addition, in the case of a narrow bag, as shown in FIG. 2, the sealing roller 2 is not driven directly, but the backup roller 24 is used.
The sealing roller 2 is driven by a backup roller 24 through a gear connection, which is the same as in the conventional example shown in FIG.

Next, the operation of the above-mentioned drive device 23 will be explained.

Detector 21 that detects the rotational state of the draw rollers 5, 5
The detection signal from the servo motor 22 or the signal from the basic rotation axis of the machine and the signal representing the film feed length are processed according to the conditions already set by the control device 20.
to drive.

The above-mentioned set conditions include those shown in FIG. In the figure, (A) is a conventional example, in which the draw roller 5 and the sealing roller 2 rotate completely simultaneously, and the circumferential speed of the sealing roller 2 is faster.

In (B), the rotation period of the sealing roller 2 is approximately half the rotation period of the draw roller 5, but the circumferential speed of the sealing roller 2 is faster in the first half. bag 1
After the tip 10゛ of 0 is placed on the stacker conveyor 6, the role of rotation of the sealing roller 2 is finished,
It is moving from deceleration to stop.

In (C), the rotation periods are approximately the same, but the circumferential speed of the sealing roller 2 is fast at the beginning of rotation, and thereafter rotates slowly.

In (D), the rotation period of the sealing roller 2 in the case of (B) is further shortened and limited to only the initial period of rotation of the draw roller 5, and the difference in circumferential speed is made larger than in the case of (B). It is.

In (E), the rotation start time of the sealing roller 2 is set earlier than the rotation start time of the draw roller 5, and the rotation end time is set earlier than in the case (D).

As described above, the rotation period of the sealing roller 2 is shortened, and the rotational speed of the sealing roller 2 is suppressed to a low level, thereby eliminating wear and noise of the sealing roller 2, etc., and making it possible to form bags under the best sealing conditions.

The above various setting conditions determine the timing of the rotation start of the sealing roller 2, the selection of the rise state of the rotation speed, and the selection of the rotation period.This selection can be effectively determined depending on the material and shape of the film used. It is something.

Although the above description has been made regarding the case of the half-folded film 4 obtained by folding the original film 16 into two, the present invention is not necessarily limited to this, and it is of course possible to use a film having folds such as gussets.

(Effects of the Invention) As described above, the rotation of the sealing roller 2 can be adjusted to the optimum conditions depending on the material and shape of the film without having to match the rotation of the draw roller 5, allowing operation under ideal conditions. is possible.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the driving of the sealing roller of the present invention, Fig. 2 is an explanatory diagram of the driving of the sealing roller for narrow bags of the present invention, Fig. 3 is an explanatory diagram of the driving state setting of the sealing roller, and Fig. 4 is an explanatory diagram of the driving state of the sealing roller. 5 is a schematic configuration diagram of a conventional bag making machine, FIG. 5 is a perspective view of the sealing device, FIG. 6 is an explanatory diagram of the drive of the conventional sealing roller, and FIG. 7 is an explanatory diagram of the sealing operation. ) is a diagram of the state at the time of welding, (b) is a diagram of the state when the tip of the bag adheres to the sealing roller at the beginning of rotation of the sealing roller after welding is completed, and (c) is a diagram of the state after further rotation from (b). (d) is a diagram showing the state after the welding point has been peeled off from the sealing roller, (D) is a diagram showing the state after the welding point has been placed on the stacker conveyor, and FIG. 8 is an explanatory diagram of the driving of a conventional sealing roller for narrow bags. 1: Sealing device, 2 Niji ring roller 3: Sealer 4 Bi-half folded film, 5 Niji draw roller
20 2 control device, 21: detector, 22: servo motor, 23: drive device. Notebook 1 play calculation 2 eyes? 3 Notebook 5th calculation θ 3 Notebook 7th Nose B

Claims (1)

[Claims] In a bag-making machine that seals after a continuous supply of half-folded film, etc. that is folded along the center line, converts it to intermittent transport using a draw roller, the sealing device is installed above the half-folded film, etc. The sealer comprises a movable sealer, a sealing roller provided at a position facing the sealer on the underside of the half-folded film, etc., and a drive device that drives the sealing roller, and the drive device drives the sealing roller. An independently driven seal for a bag making machine, etc., comprising: a servo motor for detecting the rotational state of the draw roller; a detector for detecting the rotational state of the draw roller; and a control device for controlling the drive of the servo motor based on a detection signal from the detector. Device.