JPS63307008A - Tightening amount control apparatus in automatic packing machine - Google Patents

Abstract

PURPOSE:To attain a highly efficient packing by measuring the three sides of a rectangular object in transition before feeding to an automatic packing machine and by inputting the measured values into the tightening unit of the packing machine, so that the tightening amount can be controlled in real time. CONSTITUTION:Given that, at a conveyor speed of Vmm/sec, the forward end of an object P to be packed intercepts an optical path (l) in a position (a) at time t1 and an optical path (h) in a position (b) at time t2 and passes through a point O at the time t3, the width P1 and height P2 of the object P is calculated from P1=O a=(t3-t1)Xv. The length P3 of the object is obtained from the multiplication by (v) of the time during which the optical path (m) of a photoelectric switch M is intercepted. When the object to be packed is stopped in a predetermined position on a packing machine, a band B is held fixedly by a gripper 14 acting immediately after the operation of a band restoration driving means 15 caused by a signal from a memory calculation control circuit 7. A motor 9 is energized by an operation signal from the gripper 14 and driven for only a time preset by a setting means 8, whereby the band tightening of the object is achieved by a preset desired tightening force.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device that automatically measures the band winding length of a rectangular parallelepiped object before band binding and arbitrarily controls the amount of band tightening in an automatic packing machine. This is particularly effective when applied to automatic packaging lines where items to be packed of different sizes are supplied at random.

(Background of the Invention and Prior Art) In band packaging, a band temporarily wound around an object to be packed is welded and cut after completing a pulling process and a tightening process.

Therefore, when the properties of the packaged items are constant, the band tightening force is
It is proportional to the amount of tightening relative to the winding length of the band.

Therefore, in order to pack objects of different sizes with constant tightening force, it is necessary to change the preset tightening amount according to the band winding length of each object.

Conventionally, as a method for determining the size of an object to be packed, devices have been proposed in which markings are placed on the side of the object to be packed, or devices in which a group of phototubes are arranged three-dimensionally along the transport path of the object to be packed. However, these methods have problems in terms of cost and installation space, as well as insufficient measurement accuracy, making it impossible to obtain the desired effects.

(Problems to be Solved) The present invention is based on the fact that most of the objects to be packed supplied to the automatic packaging line are rectangular parallelepipeds such as cardboard boxes, and the winding length of the band is determined by the combination of the lengths of the two sides of the rectangular parallelepiped. Focusing on the fact that it can be calculated, we also calculated various ways of binding the band (cross,
In order to be applicable to the case of K-shaped hooks, etc., the three sides of the rectangular parallelepiped are measured during transportation before being supplied to the automatic packing machine, and these measured values are input into the tightening device of the packing machine to tighten the tightening device. This allows the amount to be controlled in real time.

As a result, even if items to be packed of different sizes are randomly supplied onto the conveyor connected to the automatic packaging machine, the automatic packaging machine can maintain a constant band tightening force depending on each item to be packed and the bundling method. It is possible to unite by

In the present invention, three pairs of photoelectric switches are simply installed as rectangular parallelepiped detection means while maintaining a fixed spatial arrangement, and there is no need to modify the existing conveyor.

(Structure) The structure of the present invention is to provide a transfer restriction surface along one side of the supply conveyor of an automatic packing machine, and to provide a detection area on the conveyor with a space larger than the largest object to be packed. A pair of first photoelectric switches are provided on the front edge;
A pair of second photoelectric switches are provided on a straight line of 45 degrees and a pair of third photoelectric switches are provided on a straight line of 45 degrees passing through the intersection and perpendicular to the conveyor surface. A timer is provided for receiving the outputs of the second and third photoelectric switches and measuring the respective times up to the time when the first photoelectric switch is actuated. By controlling the operating time of a tightening device in the packing machine according to the orientation of the object to be packed when it is transferred onto an automatic packing machine, by the correction output,
The amount of band tightening of the items to be packed can be changed according to the band winding length, and the items can be automatically bundled with a constant tightening force.

In addition, when the speed of the conveyor is varied, this can be easily handled by multiplying the above-mentioned timer output and the conveyor speed output and using this multiplication output as the correction target.

In the present invention, a known tension arm type or stepped roller type is suitable as the tensioning device, and a tension roller type is not suitable.

(Example) In the figure (1) is an automatic packaging machine installed in a packaging line,
(2) is a band arch, (3) is a supply side conveyor belt, (4) is a transfer restriction surface for the packaged items P provided on the negative side thereof,
(5) is a delivery conveyor.

A three-dimensional detection area (6) is provided in a part of the conveyor (3), and a pair of first photoelectric switches M are provided on the leading edge line of the detection area.

0 is the intersection of the optical path m and the regulating surface (4).

L is a second photoelectric switch for measuring the width P1 of the object to be packed P, and is installed at a position such that its optical path 1 passes through the intersection 0 and is at an angle of 45° from the regulating surface in the horizontal direction.

H is a third photoelectric switch for measuring the height P2 of the object to be packed, and is installed so that its optical path passes through the intersection 0 and is approximately 45 degrees from the conveyor surface in the height direction.

In FIG. 4, Tl, T2, and T3 are timer counters, ■ is a speed detector that detects the conveyor speed or the transport speed of the packaged items, X is a multiplier or correction circuit, (7) is a storage arithmetic control circuit, ( 8) is a tightening position setting device, and (9) is a drive motor for the tightening device (10).

Figure 5 is a schematic diagram of the packaging machine, showing the tightening device (10).
A known stepped roller system as shown in FIG. 6 is adopted.

The step roller (11) is connected to a screw nut (12) screwed into a ball screw (13) and driven up and down.

During tightening, the band B is pulled down by the low'y (11) while being fixed by the gripper (14).

The length of the pulldown is controlled to a desired value by the operating time of the motor (9) or the output of a sensor that detects the stroke of the roller, so that a predetermined tightening force can be obtained.

In the above device, the speed of the conveyor is van/sec, and the front end of the object to be packaged P blocks the optical path J at position a at time t1, blocks the optical path J at position b at time t2, and then blocks the optical path J at position b at time t3. Assuming that the object P is passed through the zero point, the width P1 and height P2 of the object P to be packed can be easily calculated from the principle of an isosceles triangle as, for example, Pi=Oa=(t3-tl)Xv.

Further, the length P3 is a value obtained by multiplying the time during which the optical path m of the first photoelectric switch M is interrupted, that is, the OFF signal period, by V.

When the object to be packed is stopped at a predetermined position on the packing machine, the band retraction drive device (15) is actuated by a signal from the storage calculation control circuit (7), and immediately after that, the gripper (
14) works to fix band B.

The motor (9) is activated by the activation signal of the gripper (14).

The operating time of the motor is the tightening amount, and the setting device (8)
It is driven only for the time set in .

For example, the circumferential length of the object to be packed, that is, the band winding length S = 2
(PI +P2) and the tightening ratio for this is set as α, the tightening amount Q is αS, and the step roller (
If the downstream speed of 11) is dam/sec, the driving time of the motor, that is, the required tightening time is R+Q/2 d.

To specifically illustrate this, conveyor speed v=200
m+a/sec, band winding length S=1400mm, tightening ratio α=5%, step roller descending speed d=20m/s
If ec, the tightening amount Q=70+im, and therefore the downward stroke of the step roller is 35n+m, the required tightening time R is 1.75 seconds.

Note that since actual conveyor devices are often driven at a constant speed, the multiplication by the speed V can be omitted and a corrected output obtained by correcting the timer value by the tightening amount can be used as the control signal.

In this way, the band tightening force in the case of - character hanging is defined to a constant value.

When the band is cross-shaped, the object to be packed P is rotated 90° on the packing machine and the operations from the band pulling back step are repeated.

In this case 11Jf:! The output from one circuit (7) is proportional to (P2 + P3), and the band is tightened by a tightening amount that is proportional to the winding length of the band.

As explained above, even if the manner in which the bands are tied to the objects to be packed changes or the size of the objects themselves to be packed changes randomly, the device of the present invention can respond to these changes in real time. The band can be tied with a preset desired tightening force.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an automatic packaging line to which the present invention is applied, FIG. 2 is a plan view of the main parts, FIG. 3 is a side view of the main parts, and FIG.
The figure is a block diagram of the control unit, FIG. 5 is a schematic diagram of the automatic packaging machine, and FIG. 6 is a front view of the tightening device. M, L, and H are the first, second, and third photoelectric switches, respectively (6
) is the detection area, (10) is the tightening device, (11) is the stepped roller patent applicant Naigai Co., Ltd. agent Patent attorney Hiroshi Nakamura Figure 1 F Figure 2z Figure 3 Figure 4

Claims (1)

[Claims] A transfer regulating surface is provided along one side of the supply conveyor of the automatic packing machine, and a detection area with a space larger than the largest object to be packed is provided on the conveyor, and a pair of first detection areas are provided on the front edge of the detection area.
a pair of second photoelectric switches passing through the intersection of the regulation surface and the front edge and disposed on a straight line at 45 degrees horizontally with respect to the regulation surface; a pair of third photoelectric switches disposed on a straight line at 45° perpendicular to A timer is provided to correct the output of each of the timers according to the amount of tightening, and when an object to be packed is transferred onto an automatic packing machine, a tightening device in the packing machine is provided according to the orientation of the object to be packed. The amount of tightening in an automatic packing machine characterized in that the amount of band tightening of the items to be packed is changed according to the band winding length by controlling the operating time of the item using the correction output, and the items are automatically bundled with a constant tightening force. Control device.