JP2537360B2 - Packaging equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a package in which various block-shaped frozen foods and snack foods are hermetically packed in a flexible bag formed from a film-like sheet such as polyethylene. Regarding the device.

(Prior Art) Today, a transaction mode in which a product is calculated for each set weight, packaged by continuous packaging means, and processed for distribution has become widespread. Various packaging devices have been developed for this purpose. The packaging device is composed of a combination of a cylinder (cylinder) for supplying an object to be packaged and a metal mold (former) for forming the packaging material into a cylindrical shape. A vertical pillow wrapping machine is efficiently preferred and is widely used for continuous packaging of weighed goods.

In this vertical pillow packaging machine, a film-like sheet is continuously fed from a sheet roll, and while it is formed into a tubular sheet into a bag, or immediately after that, the contents are filled, and thermocompression bonding or the like is performed. Since it is sealed by sealing and separated into individual bags, it is possible to automate the bagging operation for a wide variety of products such as solid bulk materials, powders, granules, liquids, and viscous materials. The performance of this type of packaging machine is such that the accuracy of the timing adjustment between various mechanism parts such as the mechanism for supplying the packaging material from the sheet roll, the sealing mechanism, and the cutting mechanism is continuously driven. It depends on whether you can do well.

(Problems to be Solved by the Invention) The drive mechanism of such a conventional packaging device has some problems, for example, excessive stress is generated in a sheet formed in a tubular shape by a former in a supply process thereof. Do not let
Further, when feeding the sheet at a relatively high speed, the tubular sheet is fed to the sealing mechanism at a constant speed, and further, the sheet that has passed through the former is fed to the sealing mechanism in a correct trajectory. Regarding these points, for example,
The invention disclosed in Japanese Patent Publication No. 59-3325 has solved a certain degree. However, in the invention disclosed in the above publication, the feeding means between the sheet roll supply source and the former and the pulling-down means for the tubular sheet formed by the former are driven by the same drive motor, and the speed between them is adjusted. Uses mechanical means such as a clutch / brake mechanism. Therefore, there is a problem that the slack generated in the sheet cannot be removed and the speed of the sheet sent to the sealing mechanism cannot be adjusted with high accuracy.

An object of the present invention is to eliminate the above-mentioned problems of the prior art and to reliably remove the slack of the sheet and to seal the sheet when continuously processing the sheet in a series of packaging steps by a plurality of servomotors. An object of the present invention is to provide a packaging device capable of maintaining the sheet supply speed to the attachment portion at a predetermined value.

(Means for Solving the Problems) According to the present invention, in a packaging device that forms a sheet into a tubular shape and hermetically wraps an article put therein, sheet feeding for drawing heat from a film-like sheet roll. Means, detection means for detecting the feeding force applied to the sheet from the sheet feeding means, pulling-down means for pulling down the sheet formed in a tubular shape, and these sheet feeding means and pulling-down means. It is possible to provide a packaging device including a servo motor that is separately driven and a control unit that controls each servo motor according to the detected sheet feeding force.

(Operation) The present invention controls the servomotor for directly pulling out the sheet by detecting the feeding force applied to the sheet from the sheet feeding means, and drives the pulling-down means by the servomotor independent of this. In this way, the speed of the sheet sent to the sealing mechanism unit is adjusted.

(Example) Hereinafter, one example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view schematically showing an example of a packaging device for packaging a product calculated for each set weight in a flexible polyethylene bag and continuously processing the product, and FIG. 2 is a perspective view showing the packaging device. It is a figure for explaining the processing process of a sheet further typically.

The packaging device 1 is connected to a polymerization hopper of a combination weighing device (not shown) via a cone-shaped chute 3 provided on an upper portion of a frame 2, and includes a power supply, a control device 4, and a computer 5. At the rear, a sheet roll 6 made of a polyethylene film of a predetermined size is provided so as to be exchangeable, and a sheet 7 pulled out of the film roll 6 is discharged from above through a chute 3 at a set cycle from a predetermined weighed combination. In order to store the heavy goods 8, the former 9
To form a tubular sheet 10.

The feeding device 11 for the cylindrical sheet 10 includes a vertical sealing device 12
Are located below a predetermined distance from each other, and both are the first servomotors.
From 13 to the shaft, transmission belt, contact with the tubular sheet 10 through the link mechanism or the like at a predetermined pressure, and send it downward at a predetermined speed and move the vertical sealing device 12 at a speed synchronized with that speed, The longitudinal joint portion of the tubular sheet 10 is sealed by the sealing mechanism having the heat welding action. This vertical sealing operation is repeated by the box motion of the vertical sealing device 12 corresponding to the sealable length of the sealing mechanism, so that the bags sealing the length direction of the tubular sheet 10 are continuously formed. Is done.

The horizontal sealing device 14 includes a sealing mechanism that sandwiches the vertically sealed tubular sheet 10 from the front and rear and heat-welds a predetermined length in the width direction by the heat of a heater or the like inserted therein, and a central portion in the width direction. And a cutter for cutting the tubular sheet 10 from the sheet. Further, the lateral sealing device 14 includes a third servomotor 15 for driving the sealing mechanism and the cutter,
As a whole, these are moved at a constant speed in the vertical direction, that is, in the feeding direction of the tubular sheet 10, by the elevating bar 17 which converts the rotational force of the second servo motor 16 and moves up and down.

As will be described later in detail, the horizontal sealing device 14 is returned at a predetermined timing to a position corresponding to the vertical width of the bag 18 of a predetermined size in which the article 8 is sealed. Is a so-called box motion.

Based on FIG. 2, the above three servo motors 13,1
The process control from the sheet roll 6 to the packaging of the articles according to 5, 16 will be described.

The first servo motor 13 is an AC servo motor that feeds the sheet 7 from the sheet roll 6 at a constant speed. The sheet 7 is accurately positioned and supplied to the former 9 from the pinch roller 19 by a sheet tracking motor 20 for controlling the position of the sheet roll 6 in the axial direction for tracking. Then, the vertical sealing device 12 having a heater for vertical sealing that seals the sheet formed on the tubular sheet 10 at the joint portions on both sides of the sheet is formed by the servo motor 13
The sheet is processed into a cylinder in a predetermined cycle while descending at a speed synchronized with the speed.

The second servo motor 16 is an AC servo motor for lowering the horizontal sealing device 14 in synchronization with the sheet feeding speed, and the horizontal sealing device 14 seals and cuts the tubular sheet 10 in the horizontal direction. For a certain period of time, lower it at the same speed as the sheet feeding speed, raise it along the lifting bar 17 for lifting control with a predetermined lifting stroke, and return it to the position corresponding to the upper end of the bag 18 in the next cycle. There is. And horizontal sealing device
The heater and knife unit for the horizontal seal provided in 14 are
The third servomotor 15 is driven to open and close at a predetermined timing with an opening / closing stroke according to the articles supplied from the weighing device 21 and the set lateral width of the bag 18 described later in detail. Incidentally, the rising speed V ₁ of the transverse sealing device 14 is greater than the lowering speed V ₂ to be described later (V _1> V _2), constitutes a cycle speed Ya back.

22 is a dancer, which adjusts the tension of the seat 7. Further, a sensor 23 for detecting an eye mark and a printer 24 are arranged close to the sheet 7. Eye mark is a horizontal sealing device 14
Is used to form a reference signal for the position where the mouth of the bag 18 is closed and cut, and the printer 24 imprints the manufacturing date on a predetermined position of the sheet 7. Furthermore, the vibrator 8 required when the article 8 to be inserted while sealing the joint portion in the longitudinal direction by the vertical sealing device 12 has adhesiveness, and the falling speed of the article 8 from the weighing device 21 are set. It also has an accelerator 25 for accelerating.

The tension control of the seat 7 will be described below with reference to FIG. Servo motor for sheet tracking
The sheet roll 6 unwound by the 20 is a guide roller 3
It is fed out through 0, the idle roller 31, and the guide roller 32, and is pulled down by the feeding device 11 which is located below the vertical sealing device 12 and driven by a servomotor.
Therefore, when the unwinding speed becomes slow, the position of the idle roller 31 becomes high and the tension of the sheet roll 6 becomes large. Therefore, in order to detect the height, the idle roller 31 is rotated in accordance with its vertical movement. A possible Dun Server 22 is supported. A variable resistor 34 that is rotated by a rotating shaft 33 of the dancer 22 is provided, and the vertical position of the dancer 22 is detected as the resistance value of the variable resistor 34, and a sheet tracking motor is detected according to the change in the resistance value. The rotation speed of 20 is adjusted so that a constant sheet tension is always maintained. Note that limit switches LS1 and LS2 are provided at the upper and lower limit positions of rotation of the dancer 22 in order to facilitate setting of conditions in manual operation, and abnormal tension changes occur even during automatic continuous operation. It can be used as a switch that gives an alarm when you turn on.

As another embodiment, the powder brake 35 can be arranged on the rotating shaft of the sheet roll 6. That is, connect the variable resistor to the powder brake 35, and
When 22 is at the upper limit, the exciting current to the powder brake 35 is reduced to reduce the braking torque, and the sheet roll 6
The unwinding speed can be increased to reduce the tension of the seat 7, while when the tension is low, the exciting current can be increased to increase the braking torque, and the unwinding speed can be suppressed to increase the tension. Similarly, the tension of the seat 7 can be controlled.

Thus, in the packaging apparatus of the present invention, the tension of the sheet pulled out from the sheet feeding means is detected to control the speed of the servo motor for sheet tracking, and the means for pulling down the fed sheet is a separate servo. It is configured to be driven by a motor, and it is possible to always feed the sheet smoothly.

Although the present invention has been described above in some detail with reference to its most preferred embodiments, the description of the preferred embodiments does not contradict the spirit of the present invention described in the modifications of the detailed configuration and the claims. It is obvious that various modifications can be made as long as possible, or a combination thereof can be changed.

(Effects of the Invention) As described above, according to the present invention, by maintaining the tension of the sheet fed from the sheet roll at an appropriate value, unevenness of sheet feeding due to slack or excessive tension of the sheet is prevented in advance. Thus, it is possible to provide a packaging device capable of performing smooth packaging.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing a packaging apparatus according to an embodiment of the present invention, and FIG. 2 is a schematic diagram showing a sheet processing process controlled by a servomotor and a sheet tension control mechanism. 1 ... Packaging device, 7 ... sheet, 8 ... article, 11 ... feeding device, 12 ... vertical sealing device, 13 ... first servomotor, 14 ... transverse sealing device, 15 ... third Servo motor,
16 …… second servomotor, 20 …… sheet tracking servomotor, 22 …… dancer, 31 …… idle roller, 34 …… variable resistor, 35 …… powder brake.

Claims (2)

(57) [Claims] 1. A packaging device for forming a sheet into a tubular shape and hermetically packaging an article put therein, and a sheet feeding means for pulling out the sheet from a film-shaped sheet roll, and the sheet feeding means to the sheet. Detecting means for detecting the applied feeding force, pulling-down means for pulling down a sheet formed in a tubular shape, servo motors for separately driving these sheet feeding means and pulling-down means, and each servo motor And a control unit that controls the sheet feeding force according to the detected sheet feeding force. 2. A dancer mechanism that is displaced by the feeding force of the seat, and a braking means that accelerates and decelerates a servomotor that drives the sheet feeding means according to the displacement amount of the dancer mechanism. The packaging device according to claim (1).