JPH08268415A - Stretch film packaging machine - Google Patents

Abstract

PURPOSE: To provide a stretch film packaging machine which can perform a measurement of a high accuracy with one or two small number of sensors even when there is a roundness, etc., at the corners of a commodity, and can perform a packaging with a favorable finish because of the accurate measurement. CONSTITUTION: A commodity is carried from a carrying in part to a location under a packaging part, and at the packaging part, the commodity is pushed up to a horizontally spanned film, and the film ends are folded under the commodity for a stretch film packaging machine. For such a stretch film packaging machine, reflection type optical sensors 13, 13' which are provided this side of an elevator 2, and a moving means 14 which moves the sensors in the width direction of the commodity are provided to measure the width dimension of the commodity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stretch film wrapping machine, and more particularly to a stretch film wrapping machine equipped with a measuring means for detecting a width dimension of a product to be wrapped.

[0002]

2. Description of the Related Art Conventionally, in order to improve the finished state of a package in a stretch film packaging machine, the width dimension of a product to be packaged is measured before packaging, and various mechanisms related to packaging are measured according to the measured value. A means for controlling (for example, the film cut length and the folding timing of the left and right folding plates) is adopted. As a means for measuring the width dimension of the product, a plurality of sensors are provided in a straight line at predetermined intervals along the width direction, and the width of the product is measured depending on which position of the sensor is ON. (Refer to Japanese Patent Laid-Open No. 59-26426) While moving a carried-in product at a constant speed, the product is irradiated with light or ultrasonic waves from a predetermined angular position, and the amount of movement and the projection angle of the light or ultrasonic waves are used. Calculated and measured by trigonometric function. (Refer to Japanese Patent Laid-Open No. 3-111229) A method of simultaneously measuring the centering of a product. Etc.

[0003]

The product width measuring mechanism equipped in the above-mentioned conventional stretch film wrapping machine is as follows.
In this case, since the number of sensors that can be arranged in a straight line is limited, there is a problem in that the dimensional accuracy measured is rough. In addition, in the device (1), an error occurs in the measured value due to the roundness (chamfer) or the chamfering of the corner of the product (tray).
Further, in the case of, there is a problem that the centering device is expensive. Therefore, at least and because there is a problem in measurement accuracy, it is difficult to improve the packaging finish even if various mechanisms are controlled based on such measured values. In addition, although the measurement accuracy is better than that, since the apparatus is expensive, the cost of the packaging machine as a whole is so high that it cannot be used for a general packaging machine.

The present invention has been made in view of the problems of the above-mentioned conventional technique, and the purpose thereof is to:
To provide a stretch film wrapping machine capable of performing highly accurate measurement even with rounded corners of a product with a small number of sensors such as one or two, and thereby performing a good finished wrapping. It is in.

[0005]

[Means for Solving the Problems] The technical means taken by the present invention to achieve the above-mentioned object is to convey a product from a carry-in section to under a packaging section, and to carry the product on a film stretched horizontally in the packaging section. In a stretch film wrapping machine that pushes up and folds the film end under the product, the reflection type optical sensor provided at a position closer to the elevator, and the moving means for moving the sensor in the width direction of the product, the sensor Is characterized in that the width dimension of the product is measured by the movement amount during the detection of the product.

The position on the front side of the elevator provided with the reflection type optical sensor is from the product placing table in the carry-in section to the position where the product placed on the product placing table is transferred to the elevator installed below the packaging section. It is preferable that the carry-in section is near the front side of the product placing table. The number of reflection type photosensors used may be one or two, and when two reflection type photosensors are provided, they are configured to move in diametrically opposite directions in which they are separated or approaching each other. The width measurement when two reflective optical sensors are provided is determined based on a value obtained by adding the movement amount of one sensor during product detection and the movement amount of the other sensor during product detection.

Further, the moving means of the above-mentioned reflection type optical sensor may be a chain or belt endlessly rotated by a motor, an air cylinder, a ball screw mechanism or the like, and two reflection type optical sensors are used to directly oppose each other. In the case of moving in the direction, the above-mentioned endlessly rotatable chain or belt is used, and the sensors can be attached to the forward path side and the backward path side of the chain or belt to separate or approach the both sensors.

[0008]

According to the above-mentioned means, the weight of the product supplied to the carry-in section is measured on the mounting table, and when the measurement is completed and the stability signal is output, the conveyor belt is operated and attached to the belt. Push the product on the mounting table with the pusher and transfer it to the elevator. Therefore, the width dimension of the product is measured by moving the reflective optical sensor in the width direction of the product until the product is placed on the placing table and the weight measurement is completed and the product is transferred by the pusher. In the measurement, the presence or absence of the product is detected by the presence or absence of the reflected light, and the width dimension is measured and calculated from the moving distance of the reflective photosensor. And, when the above-mentioned reflection type optical sensor is provided near the front of the carry-in section,
The sensor does not obstruct the loading of the goods to the placing table of the loading section, and stable measurement is possible. Furthermore, when two reflection type optical sensors are provided and moved in the opposite directions, the width of the product is divided into two parts from the center to the left and right, so that quick measurement is possible. Moreover, since the widths are obtained by adding the movement amounts of the two sensors, it is possible to perform measurement even if the product is placed with a deviation from the central position of the product placing portion.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. The stretch film wrapping machine shown in FIGS. 1 to 3 is a wrapping machine provided with a mechanism (pre-stretching mechanism) for expanding the width direction of the film, and an article to be packaged (product) 20 is placed on the side of the machine frame A. The product placing part a is provided, and the product placing part a
A size detecting mechanism E including reflective optical sensors 13 and 13 'and moving means 14 that moves the reflective optical sensors 13 and 13' in the width direction of the product is provided near the front side of the product. The object to be packaged 20 placed on the placing part a is the conveyor 1
Is transported to the elevator 2 provided inside the machine frame A.

A positioning stopper 15 for placing the article 20 to be packaged is provided on the rear side edge of the product placing section a so as to stand upright, and the outer peripheral surface of the belt 1'of the conveyor 1 is lengthwise. A pusher that presses and transfers the object to be packaged 20 at a predetermined interval.
16 is fixed, and such a conveyer conveyor 1 is configured to be intermittently driven. In the intermittent driving, the pusher 16 attached to the belt 1'of the conveyor 1 is a pusher initial position sensor located in front of and below the product placing portion a.
It is stopped by being detected by 17, and the product placing part a
The object to be packaged 20 is placed on the package, the weighing is performed, and the operation is performed by outputting a stable signal indicating the completion of the weighing.

A packaging portion b is provided above the elevator 2, and a film roll arranging portion 3 is provided on the side of the packaging portion b.
And a film holding means B for holding the leading end of the film 4'unrolled from the film roll 4 set in the placement section 3, and the film held by the film holding means B is sandwiched and pulled out, and the packaging is performed. The film feeding means C for conveying to the section b is arranged close to the tip of the film holding means B, and the film held between the film holding means B and the film feeding means C is pulled out by the film feeding means. A cutter D that cuts to a predetermined length is arranged.

The film holding means B holds and holds both side portions of the film 4'unrolled from the film roll 4 set in the film roll arranging portion 3. As shown in FIG. The endless belt 5 arranged and the film 4 ′ supported on the surface of the endless belt 5.
And a pressing member 6 for pressing the endless belt 5 toward the endless belt 5, and holding means composed of the endless belt 5 and the pressing member 6 are arranged at the front and rear at an interval corresponding to the interval of the film width. 6, one end of which is pivotally supported and is provided so as to be freely opened and closed. The endless belt 5 is configured to be driven and rotated by a motor.
Incidentally, the film holding means B may optionally be configured so that one or both of the holding means can be moved in the width direction according to the film width so as to correspond to the film roll 4 set in the film roll arranging section 3.

The film feeding means C is a pair of upper and lower endless elastic belts 7 and 7'for sandwiching the side end portions of the film.
And a pressing belt 8 arranged on the upper surface of the lower elastic belt 7'on the starting end side so as to be overlapped with each other. The distance is the same as that of the pair of front and rear holding means. The pair of front and rear components are supported by the mounting frames 9 and 9 ', and the two mounting frames 9 and 9'are arranged below the mounting frames 9 and 9'and intersect each other at a right angle. The mounting frame 9 ', which is supported by the rods 10 and 10' via connecting members 11 and 11 ', has one feed means C1 attached thereto, and the other feed means C2 has a mounting frame 9 attached thereto. The movable side feed means C2 is connected to an interval expansion means (not shown) so that the movable side feed means C2 is movable.
It is configured so that the distance between and can be adjusted narrowly.

The pair of upper and lower endless elastic belts 7 and 7'constituting the above-mentioned feeding means are driven and rotated in the same direction so that the film can be sandwiched and conveyed, and the driving system is a motor 12 with a speed reducer. Side sprocket 7'rotates the drive roller around which it is wound, and the chain sprocket is fixed to the shaft of the drive roller, and chain sprocket is fixed to the shaft of the drive roller around which the upper elastic belt 7 is wound. The power is transmitted by winding the chain over and the upper elastic belt 7 is also rotated. still,
The upper and lower elastic belts are equipped with a tension adjusting mechanism on the way so that the film can be sandwiched and conveyed stably and reliably.

A dimension detecting mechanism E for measuring the width dimension of a commodity, which is the basis for determining the drawing length of the film.
Is placed near the product loading section a of the product loading section 2
It is composed of individual reflective optical sensors 13, 13 'and moving means 14 for moving the reflective optical sensors 13, 13' in the width direction of the product. The reflective optical sensors 13, 13 'are projectors. If a light receiver is provided and the projected light is reflected by the object to be packaged 20 and the reflected light is received by the light receiver, the object to be packaged 20
The width is measured, and if there is no reflected light, the width limit is confirmed. (See FIGS. 7, 8 and 9) The moving means 14 for moving the above-mentioned two reflection type optical sensors 13 and 13 'in the width direction of the product extends over the stepping motor 141 of the drive source and the driven pulley 142. Reflective optical sensor 13 on the outward side (upper side) of the belt 143 wound around
On the return path side (lower side), the reflection type optical sensor 13 'is fitted to the guide rods 144, 144' via the sliding bodies 145, 145 'which slide in the left-right direction, and A limit switch 146 for returning the reflective optical sensors 13, 13 'to the origin position (initial position) and a limit switch 146' for detecting the limit position of movement are provided. (Refer to FIG. 6) The origin position (initial position) of the two reflective optical sensors 13 and 13 'is near the position corresponding to the center in the width direction of the carry-in section. When the product with the narrowest width is placed on the product placement part a, it is several tens of millimeters from its width.
With the narrowed position, the distance for moving the reflection type optical sensors 13 and 13 'for the dimension measurement becomes short, and the advantage that the time required for the measurement can be shortened is obtained. Further, the movement of the reflection type optical sensors 13 and 13 'is started at the same time as the movement of the pusher 16 is started, and the pusher 16 is moved from the position of FIG. 4 to the position of FIG. It is a moving speed that can be located outside. Therefore, the pusher 16 can be measured in a short time without disturbing.

Next, the operation of the above-mentioned width dimension measuring mechanism will be described with reference to the operation explanatory diagrams and the flow charts of FIGS. 4, 5, 7 to 9. First, the article to be packaged 20 is placed on the product placing portion a of the carry-in portion. In the absence state, the conveyer 1 is stopped when the pusher 16 attached to the belt 1'is detected by the pusher initial position sensor 17. In that state, when the article to be packaged 20 is placed on the product placing portion a, weighing of the article to be packaged is started (step 1), and when a stable signal indicating the completion of weighing is output, the conveyor 1 is started (step 2), The counter for inputting the left and right width dimensions is reset to zero (step 3), the left and right reflective optical sensors 13 and 13 'start moving in a direction in which they are separated from each other, and the width dimension measurement of the packaged object 20 is started. (Step 4). The movement of the left and right two reflection type optical sensors 13 and 13 'moves in a direction in which they are separated from each other as shown in FIGS. 7 and 8, and the light projected from the sensors impinges on the article to be packaged 20 and the reflected light is reflected. When the light is received, it is turned on, and when there is no reflected light, it is turned off, and the numerical value of how much it moved from the initial position until there is no reflected light is input and stored in the counter. Therefore, if the reflection type optical sensors 13 and 13 'start moving and the reflection type light sensor 13' on the left side receives the reflected light (step 5), the numerical value associated with the movement is counted by the counter ( Similarly, when the reflection type optical sensor 13 on the right side also receives the reflected light (step 6) (step 7), the right counter counts the numerical value of the movement (step 8) and the left and right sensors receive the reflected light. In the period, (step 4) to (step 8) are repeated.

Then, as shown in FIG. 9, when the reflection type optical sensors 13 and 13 'no longer receive the reflected light, the left sensor 13' first makes a NO judgment (step 5). A numerical value is input to the counter and held, and the right sensor
The presence or absence of reflected light in 13 is determined (step 9), and if there is reflected light (step 8), the counter is counted,
If there is no reflected light, input and hold the value when the reflected light disappeared, add the count values of the left and right counters, and add the width of the article 20 (distance between left and right sensors at the origin position + left counter The count value + the count value of the right counter is calculated and calculated (step 10). 20 to be packaged
When the width measurement of the left and right is completed, the left and right reflective optical sensors 13,
13 'moves the stepping motor 141 of the moving means in the opposite direction and the left and right sensors 13, 13' move toward each other and moves to the position detected by the limit switch 146 for origin position detection, and the next measurement Wait for (step 11). After that, the packaging process is started, and the film 4'is fed out from the film roll 4 and cut into a required length based on the measurement value obtained by the above-mentioned width dimension measurement, and the cut film 4'is the film feed. While being stretched by the means C (step 12), the width of the film 4'is expanded to a predetermined width according to the height and depth dimensions of the article to be packaged 20 which are separately measured, and the expanded and stretched film 4'is stretched and stretched. The object to be packaged 20 is pushed up by the elevator 2 onto the suspended film to cover the surface of the object to be packaged 20 with the film, and then the folding timing of the left and right folding plates 18 for folding the end of the film to the lower side of the object to be packaged is also the above-mentioned. Determined by the width measurement of the
13) Then, the left and right sides and the rear side are folded, and the article to be packaged 20 is discharged by the discharge pusher 19 (step 14) and the front side is folded and welded, and one cycle is completed. In the conveyor 1 started in (step 2), the next pusher 16 attached to the belt 1'is the pusher initial position sensor 17
It stops when it is detected by.

In the above-mentioned embodiment, the conveying direction of the article to be packaged 20 and the drawing direction of the film 4'from the film roll 4 are orthogonal to each other, but the conveying direction of the article to be packaged and the film drawing direction are the same. In some cases, the roll of the optimum width is selected from several types of film rolls having different film widths, the amount of expansion when the film width is expanded to a predetermined width is determined, etc. Since the dimensions can be used, the present invention can be applied to a packaging machine in which the transport direction of the article to be packaged and the film drawing direction are the same.

Further, since the width dimension of the article to be packaged is divided into two parts at the center of the article to be divided and stored on the left side and the right side, when the article to be packaged is placed on the product placing section, it is placed. When the center of the packaged item is displaced from the center of the part in the left-right direction, the difference is calculated and calculated from the measurement value of the width dimension described above. If it is a packaging machine, it is possible to adjust the misalignment of the packaged object at the time of placement and attach the label to the correct position of the packaged object.
It should be noted that if both sensors return immediately when they no longer detect the product, the distance traveled is reduced, the life is increased, and the speed is increased. Also, for the first product, 2
Each sensor performs measurement while moving away from each other, stops at both ends of the movement range, and moves for the next product from that position while moving closer to each other for measurement The directions may be changed alternately.

The size of the reflection type optical sensor is not limited to two in the above-mentioned embodiment, but it is possible to use only one, and in that case, the origin position of the sensor is located in one of the width directions. The same action and effect as those of the above-described embodiment can be obtained by setting the above position and moving from that position toward the other.

[0021]

According to the stretch film packaging machine of the present invention, the width dimension of a packaged item is measured by the presence or absence of reflected light. Therefore, even if the corners of the packaged item are curved. The width dimension can be measured accurately, and moreover, the width dimension is calculated from the moving distance of the reflective optical sensor, so that accurate measurement is possible. As a result, the measurement accuracy can be improved, and the control of the film pull-out length required for packaging, the folding plate folding timing, the used film roll selection, the film width expansion amount, etc. can be performed accurately, and thus the finish can be achieved. Good packaging can be done. Further, in the case of the constitution as set forth in claim 2, the sensor is not obstructive when the article to be packaged is placed on the article placing portion, and moreover, there are few obstacles to the measurement by the sensor, so that stable measurement should be performed. You can Further, as shown in claim 3, when two reflective optical sensors are used and are moved in directions away from each other and approaching each other, the width measurement can be bisected from the center to the left and right.
It has an advantage that it can be measured in a short time, and thus the number of packages per unit time can be increased. Then, when the movement amount of the two sensors is added to obtain the width dimension of the product as in claim 4, even if the product is placed with a deviation from the central position of the product placing portion. It becomes possible to measure.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional side view showing an outline of a stretch film packaging machine according to the present invention.

FIG. 2 is a vertical sectional front view of the same.

FIG. 3 is a plan view showing a carry-in section.

FIG. 4 is a partially cutaway enlarged side view showing a state in which the transport conveyor stops at an initial position and width measurement is performed by a reflective optical sensor.

FIG. 5 is an enlarged side view showing the state in which the conveyer is started from the state of FIG. 4 and the pusher starts to obstruct the measurement.

FIG. 6 is a partially cutaway perspective view showing a moving means of the reflective optical sensor.

FIG. 7 is an explanatory diagram showing the origin position of the reflective optical sensor with respect to the object to be packaged.

FIG. 8 is an explanatory view showing the moving state of the reflective optical sensor.

FIG. 9 is an explanatory diagram showing a state in which the width measurement by the reflective optical sensor is completed.

FIG. 10 is a flowchart showing a program for measurement by a reflection type optical sensor.

[Explanation of symbols]

 A ... Machine frame E ... Dimension detection mechanism 1 ... Conveyor 2 ... Elevator 13, 13 '... Reflective optical sensor 14 ... Moving means

Claims (4)

[Claims] 1. A stretch film wrapping machine for transporting a product from a carry-in section to under a wrapping section, pushing up the product on a film stretched horizontally in the wrapping section, and folding a film end under the product, a position in front of an elevator. A stretch characterized in that it comprises a reflective optical sensor provided in the device and a moving means for moving the sensor in the width direction of the product, and the sensor measures the width dimension of the product based on the amount of movement during detection of the product. Film packaging machine. 2. The stretch film packaging machine according to claim 1, wherein the reflection type optical sensor is provided in the vicinity of the front of the loading section. 3. The reflection type optical sensor is moved in the moving direction by 2.
The stretch film wrapping machine according to claim 1 or 2, wherein a single piece of the stretch film wrapping machine is provided, and the two sensors move in a direction of moving away from or approaching each other. 4. The width dimension of a product is determined based on a value obtained by adding a movement amount of one sensor during detection of a product and a movement amount of another sensor during detection of a product. The described stretch film packaging machine.