JP2795247B2 - Stretch wrapping machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stretch wrapping machine for wrapping an object to be wrapped, which comprises a product and a tray on which the product is placed, with a film. More specifically, the present invention relates to tray loading control of a stretch packaging machine.

[0002]

TECHNICAL BACKGROUND Stretch wrapping machines are often used to automatically package objects to be packaged, which consist of products and trays on which the products are placed, but various types of products are distributed. At present, trays on which products are placed for reasons such as the shape and properties of the products or differentiation from other products are distributed with trays having different shapes and materials along with these various types of products. There is a tray called a stack tray, which has a small bottom surface and is easy to fall down (hereinafter, referred to as a "low stack tray").

[0003]

2. Description of the Related Art Conventionally, this type of stretch wrapping machine has a first fold portion which pushes and folds an edge of a film on a lower surface of a wrapped product comprising a product and a tray on which the product is placed; A packaging unit including a second folding unit that is folded along with the removal of the package, a product placement unit for placing the packaged product, and a packaging unit for packaging the packaged product placed on the product placement unit Loading means for carrying in below, elevating means for pushing up the packaged material carried below the packaging means above the packaging means, film transport means for transporting a film between the packaging means and the carrying means and stretching and holding, An unloading means for unloading the packaged articles, and a control means for controlling the entire packaging machine, wherein the loading means arranges the conveyers side by side at predetermined intervals on the same axis and in the circumferential direction of the upper surface of the conveyer. Pushing the package at predetermined intervals It is composed of a conveyor part with an upright shear, and the upper part of the product placement part is formed in a plurality of flat plates at a predetermined interval, and is disposed within the interval so that the product placement part upper surface is higher than the conveyor upper surface. doing.

[0004] The packaging process is described in detail. An article to be packaged placed on a product placing section is pushed and moved by a pusher, placed on the upper surface of a conveyor, and moved to a predetermined position. Then, the moved packaged object is pushed up by the elevating means to the stretched and held film, and the upper surface of the packaged object is covered with the film. In this state, the folding members (the left and right folding plates and the rear folding plate) are moved to move the film edge. Part is pushed down and folded into the lower surface of the package, leaving only one side in the unloading direction, and then the package moves to the upper part of the fixed folding member (unloads) so that the remaining film edge is unwrapped. It is folded naturally on the bottom of the object, and packaging and unloading are completed at the same time.

In this conventional stretch wrapping machine, the carrying-in means, that is, the conveyor section is driven at a constant speed except when stopped, and the moving speed of the pusher simply moving out of the product storage section and the speed during passage through the product storage section. The moving speed was constant.
However, this conveyor speed is set to a high speed to improve productivity, and when the high-speed pusher abuts against a tray with a small bottom such as the above-mentioned low stack tray, the top surface of the product loading section does not fall down. Was made to be slippery to accommodate various types of trays.

[0006]

However, when an article to be packaged is accidentally placed on the article placing section and placed obliquely with respect to the carrying-in direction, the upper surface of the article placing section is easily slipped, so that the Both ends alternately come into contact with the pushers near both ends, and the product placing section moves while repeating left and right rotations, and moves on the conveyor in an oblique state. When the obliquely wrapped object is wrapped by the above-mentioned wrapping means, a packaging defect is caused, which causes a problem that a product is damaged or a machine is broken down.

SUMMARY OF THE INVENTION The present invention has been made in view of the conventional circumstances, and an object thereof is to provide a stretch wrapping machine capable of securely wrapping a tray even when the tray is placed at an angle, without causing a carry-in failure. The purpose is to do.

[0008]

The technical means taken to achieve the above object is a packaging means for folding an edge of a film on the lower surface of a packaged object comprising a product and a tray on which the product is placed. A product placing section for placing the article to be packaged, loading means for loading the article to be packaged placed on the product placing section below the packaging means, and packaging of the article loaded below the packaging means. Means for raising and lowering the means upwardly, and film transfer means for transferring and stretching the film below the packaging means, wherein the carry-in means arranges the conveyors coaxially at predetermined intervals and at the same time on the upper surface of the conveyor. It is composed of a conveyor section having a pusher that pushes the packaged article upright, and the upper part of the product placement part is formed in a plurality of flat plates at predetermined intervals so that the upper surface of the product placement part is higher than the upper surface of the conveyor. Within the above interval In a stretch packaging machine, a packaged object is placed on a product mounting portion, and the packaged object carried in by the loading means is pushed up to a stretched and held film, and a film edge is folded and wrapped on the lower surface of the packaged object to be packed. The loading means solves the above-mentioned problem by correcting the posture of the packaged object by slowing down the moving speed of the pusher during the passage of the product placing portion compared to after the passage of the product placing portion. The fact that this pusher has slowed the moving speed while passing through the product placement section compared to after passing through the product placement section means that the pusher does not repeat the left and right rotation even if the pusher abuts the packaged object placed diagonally. As a result, the speed at which the posture immediately after passing through the product placement section is corrected, and varies depending on the individual because uncertain factors such as the shape of the tray, the coefficient of friction, and the weight of the product are included. Therefore, the speed may be set individually. In addition, the speed pattern in the moving speed section where the pusher is delayed includes constant speed motion throughout, increasing speed gradually, accelerating at a constant acceleration, giving arbitrary speed change, etc. Includes As means for changing the speed of the pusher (the speed of the conveyor unit), a drive source for driving the conveyor unit, for example, an actuator that obtains a linear or rotational output, (a hydraulic or pneumatic linear cylinder, or a rotary motor, Or a motor with a brake using electric power, a stepping motor, and the like,
Among them, a conveyor unit using a stepping motor, which enables accurate control, as a direct drive source is preferable. ) To control the speed by transmitting a control signal (claim 1).

[0009] Further, the moving speed of the pusher while passing through the product placing portion is increased. (Claim 2)

[0010]

According to the above technical means, the following effects are obtained. According to the first aspect, when the pusher slows down the moving speed during the passage of the product placement section compared to after the passage of the product placement section, the pusher contacts the package placed on the product placement section. Reduce impact force. According to the second aspect, the moving speed of the pusher during the passage of the product placement section is accelerated, and the time during which the pusher alternately contacts the packaged object is reduced.

[0011]

Next, embodiments of the present invention will be described with reference to the drawings. FIGS. 1 and 2 illustrate a stretch wrapping machine suitable for wrapping objects to be wrapped with a weighing label printer. Symbol A is a stretch wrapping machine, B
Is a packaging machine main body, C is a weighing label printer, D is a control means, T is a tray, and F is a film.

The packaging machine main body B includes a product placing section 1, a loading means 2, a film cutting and holding means 3, a film transporting means 4, a lifting / lowering means 5, a packaging means 6, a carrying out means 7, It comprises a means 8 and a packaging machine main body control section 9. Briefly, from the feeding roll R to the film F
The film F is delivered from the film cutting and holding means 3 to the film transport means 4 and transported below the packaging means 6. On the other hand, the article to be packaged W placed on the product placing section 1 is carried in by the carrying-in means 2 above the elevating means 5. Next, the packaging object W is pushed up by the lifting / lowering means 5 toward the film F stretched on the film transport means 4,
Fold the edge of the film F. Then, the packaged object W is pushed by the unloading means 7 to be unloaded onto the sealing means 8 to seal the folded surface, and the label issued by the weighing label printer C described later is used for the packaged unpackaged material W. Pasting and packaging on the film F side is completed.

As shown in FIGS. 3 and 4, the product mounting portion 1 has a flat plate shape at a predetermined interval so that the upper portion does not interfere with a plurality of belt conveyors 23 to be described later. Are formed so as to protrude, and can be positioned by abutting the tray. The product placement unit 1 is provided such that the upper surface of the product placement unit 1 is higher than the upper surface of the belt conveyor 23, and the lower weighing unit c
6 weighs, and a weighing value signal is transmitted to the weighing label printer control unit c1. It should be noted that a product width detection sensor and a product height detection sensor (not shown) for measuring the placement displacement and the width of the packaged object W placed on the product placement unit 1 are provided. However, the description is omitted because it is not directly related to the present invention.

The loading means 2 comprises a conveyor section 21,
A carry-in motor 22 composed of a stepping motor, a belt conveyor 23, a pulley 24, a shaft 25, a strip-shaped pusher 26 erected at a predetermined interval in a circumferential direction on a belt upper surface of the belt conveyor 23, The belt conveyor 23 is arranged side by side at a predetermined interval between the shafts 25. The conveyor unit 21 is stretched so that the belt above the belt conveyor 23 can move into the gap of the product placement unit 1. The pusher detection sensor 27 is a transmission-type optical sensor. The pusher detection sensor 27 detects the standby position (initial position) of the pusher 26, and is set to be a starting point of the number of steps described later.

The film cutting and holding means 3 includes a cutter 31
And film receiving portions 32 and 33. The leading end of the film F is transferred by both of the film receiving portions 32 and 33 to the film transfer means 4 described later by moving the two ends upward as they are. F
Is cut off.

The film transport means 4 includes a conveyor 41
, A clamp unit 42, a unit moving unit 43, and a support frame 44. The conveyor section 41 is composed of a pair of left and right conveyor units 46 driven by a motor 45 and disposed below the packaging means 6 described below. In this conveyor section 41, the respective conveyors are synchronized with each other, and the pulley 47 at the transfer side end (the right side in FIG. 1) is opened when the film F is transferred from the film cutting and holding means 3 to the unclamped state. When the film F is delivered, it is closed immediately to hold and transport the film F. The clamp unit 42 is composed of a pair of upper and lower clamp units 48 having an open / close function (the upper part is fixed and the lower part is movable), and the transferred film F is clamped and stretched.
The film F is released from the holding state based on the packaging timing. The unit moving section 43 includes a guide 49, a communication member 410, and an actuator (not shown) for reciprocating. The unit moving section 43 is provided below the support frame 44 that supports the conveyor section 41 and the clamp section 42. The distance between them is adjustable.

The elevating means 5 includes an elevating part 51 and a link part 5.
2 and a cam portion 53. The elevating unit 51 is formed so that the belt conveyors 23 continuously provided at predetermined intervals are crotched, and the article to be packaged W is loaded and pushed up on the upper surface of the elevating unit 51. One end of the link section 52 is
And the other end is rotatably supported by a machine frame or the like. The cam portion 53 is provided such that the cam surface is in contact with a midway area of the link portion 52, and the elevating portion 51 is moved up and down by one rotation of the cam by the motor.

The packaging means 6 comprises a first fold 61 and a second fold 62. The first folding part 61 includes the left and right folding plates 6.
3 and a rear folding plate 64. The left and right folding plates 63 and the rear folding plate 64 are each provided with a horizontal moving mechanism (not shown), and are horizontally movable in a positional relationship such that the lower surface of the raised tray T slides on the lower surface. Second fold 62
Is composed of a folding roller 65, and is erected and fixed to a machine frame or the like in a direction orthogonal to the unloading direction in a positional relationship such that the lower surface of the tray T slides when the packaged object W is unloaded.

The unloading means 7 comprises a horizontal moving mechanism (not shown) having a pusher 71 for pushing the side surface of the tray T, and causes the unloading section 72 to unload the article W to be packaged. The sealing means 8 includes a heat sealing portion 81 in which heaters are arranged in parallel. The packaging machine main body controller 9 will be described later together with the weighing label printer controller c1.

The weighing label printer C calculates a product price from a unit price set in advance based on data weighed by placing the article to be packaged W on the product placing section 1 of the packaging machine body B. Calculate, print the price and other product data on label paper and issue it, hold the issued label by suction, and stick it on the film F surface of the packaged article W, It is controlled by the weighing label printer control unit c1.

The control means D includes the above-described packaging machine main body control section 9
And a weighing label printer control unit c1. The packaging machine main body control unit 9 includes an interface 92, a ROM 93,
RAM 91, operation unit 94, mechanism driving unit 95,
, And each is connected to the CPU 96. The interface 92 is a circuit for communicating with the weighing label printer control unit c1, and is connected to the interface c2 of the weighing label printer control unit c1. The ROM 93 stores a control program executed by the CPU 96, and controls the packaging machine main body B.
As for the carrying-in means 2, the distance from the standby position (initial position) of the pusher 26 to the position where the article W is delivered to the elevating means 5 is converted into the number of steps (pulse signal) of the carrying-in motor 22 and is set in advance. The position is recognized by associating the number of steps with the moving distance of the pusher 26. A program for controlling the moving speed (conveyor speed) of the pusher 26 by changing the number of steps, that is, changing the time axis of the pulse signal (changing the frequency) is incorporated. RAM91
Indicates tray data. Tray data is
It consists of a tray number, packaging conditions and the like. The tray number is a number for simple recognition, and this number is used as an identification number, and the following is allocated and stored for each tray number.
Packaging conditions: the clamp section 42 of the film transfer means 4,
To adjust a series of timings related to the packaging of the packaging means 6 and the like to a standard timing (timing when a reference tray is used) to a timing according to a tray shape (length, width, height) to be packed. Is temporal data. The operation unit 94 includes a switch for inputting, for example, starting and stopping the packaging machine body B. Mechanism drive unit 9
Reference numeral 5 denotes an interface for directly communicating with each mechanism of the packaging machine body B when packaging is performed. The motor 54 drives the lifting / lowering means, the carry-in motor 22 drives the carry-in means 2, and the film transport means 4. Motor 45 for driving
A control signal or a detection signal is input / output to / from the product width detection sensor, the product height detection sensor, the pusher detection sensor 27, and the like via the mechanism driving unit 95. Among them, the control signal of the carry-in motor 22 for driving the carry-in means 2 is obtained by amplifying a pulse signal output based on a command from the CPU 96 by the mechanism driving unit 95 and carrying the carry-in motor
To be supplied.

The weighing label printer control unit c1 includes an interface c2, a ROM c3, a RAM c4, a display operation unit c5, a weighing unit c6, a printing unit c7, a suction unit driving unit c8, a product detection sensor c9, , And each is connected to the CPU c10.
The interface c2 is a circuit for communicating with the packaging machine main body control unit 9, and is connected to the interface 92 of the packaging machine main body control unit 9. The ROM c3 is a CPU c10
Are stored. RAMc
Reference numeral 4 stores a flag, a register, and product data to be executed by the CPU c10. Product data is part number,
It consists of a product name, unit price, tare, and tray number. The part number is
This is a number for simple recognition.
The following items are assigned and stored for each product number. Product name: Name of the product, ie, “High-grade roast for Matsuzaka beef and shabu-shabu” etc. Unit price: For example, unit price per 100 grams, ie, “2000” Tare: For example, tray weight (gram), ie, “25” Tray number… The description is omitted because it is the same as the above. The display operation unit c5 includes a keyboard, a liquid crystal panel, and the like, and is configured to input and output various information.
Product data and tray data can be set. The weighing unit c6 transmits a weighing signal of the packaged object W placed on the product placement unit 1 to the CPU c10. The printing unit c7 is composed of a thermal printer or the like, and has a CPU c1.
Based on the 0 instruction, a label on which the product name, weight, price, unit price, effective date, bar code, and the like are printed is issued. The suction unit driving unit c8 is a mechanism unit that suctions and holds the issued label and affixes it to the film surface of the packaged object. The product detection sensor c9 detects the presence or absence of a product when attaching a label.

A series of operations of the stretch wrapping machine A configured as described above will be described with reference to a flowchart shown in FIG. (Step 1) The operator inputs a product number corresponding to the product name to be packaged by using the keyboard of the display operation unit c5 while viewing the product data displayed collectively on the display operation unit c5. (Step 2) When the key is input, the corresponding product data is read. (Step 3) The tray number stored in the product data is sent from the CPU c10 to the CPU 96, and the corresponding tray data (position data, packaging conditions) is read. (Step 4) ... The corresponding packaged object W is placed in the product placing section 1.
And a determination is made as to whether the weighing value is stable. When the weighing value is stabilized, a weighing value signal is transmitted to the weighing label printer control unit c1. (Step 5) When the weighing is completed, the carry-in means 2 (belt conveyor 23) is started at a low speed (pulse signals at long intervals are supplied to the carry-in motor 22), and the pusher located at the origin (the standby position of the pusher 26) is started. 26 moves to push the package W on the product placement section 1 to correct the posture of the package placed diagonally. (See FIG. 5) (Step 6) The distance (the number of steps) from the origin to the end of the product placement unit 1 (the side of the elevating means) is stored in advance, and the packaged object W is always checked by making a comparison judgment. It is determined whether or not has passed over the product placement unit 1. (Step 7) When the article to be packaged W has passed over the product placing section 1, the apparatus starts up at a high speed (a pulse signal with a short interval is supplied to the carry-in motor 22). (Step 8)... The number of steps up to the desired predetermined position based on the position data (the number of steps) is always compared and determined to determine whether or not the packaged object W has reached the desired predetermined position. Do. (Step 9) The film F cut by a predetermined length by the film cutting and holding means 3 is stretched and held by the film transport means 4, and the packaged object W is pushed up by the upper surface of the elevating part 51 of the elevating means 5. (Step 10) When the push-up is completed, the loading means 2 (belt conveyor 23) is started at a high speed, and the pusher 26 returns to the origin (standby position). (Step 11) Left and right folding plates 63 of the first folding portion 61
And the rear folding plate 64 is horizontally moved to push the edge of the film to perform left / right and rear folding, and
Descends. (Step 12) The pusher 71 of the carrying-out means 7 pushes the rear surface of the tray T to carry out to the carrying-out section 72. At this time, the folding roller 63 of the fixed second folding portion 62
When the article to be packaged moves (unloads) to the upper part, it is folded naturally, and packaging and unloading are performed simultaneously. (Step 13) After the price is calculated based on the weighing value signal obtained in Step 4 and the product data, a label on which these data are printed is issued from the printing unit c7, and the suction unit driving unit c8 outputs the label. Then, the issued label is sucked and held, and attached to the film F of the packaged object W. (Step 14) The film F on the lower surface of the article to be packaged W is sealed by the heat sealing section 81 of the sealing means 8 as the carry-out section 72, and the packaging is completed.

In this embodiment, a program for controlling the transport means 2 is incorporated in the control program.
By storing speed data for each type of product or for each type of tray in the tray data or product data stored in the AM 91 or the RAMc4, the control program also configures a corresponding program to specify the product or tray. It may be controlled individually. Further, the control of the loading means 2 is not limited to the control performed by the control means D for controlling the entire packaging machine, but may be a control means for controlling the loading means 2 exclusively. Further, in the present embodiment, an example in which a drive source for driving the conveyor unit is a direct drive source using an electric drive for driving the conveyor unit for the reason that accurate control is possible, but the present invention is not particularly limited to this. Instead, a linear cylinder using a hydraulic pressure or a pneumatic pressure, or a rotary motor as a direct drive source may be used. In this case, a control means having a hydraulic pressure / pneumatic circuit in addition to the electric control. Becomes

[0025]

As described above, the present invention has the following advantages. (Claim 1) Since the pusher has a lower moving speed while passing through the product placement section than after passing through the product placement section, thereby reducing the impact force when the pusher contacts the packaged object, The posture is gradually corrected without the loaded object to be packaged moving unnecessarily on the product mounting portion. Therefore, the user is transferred to the conveyor section in a proper posture and is carried into the set predetermined position without error, so that packaging is performed without causing a packaging failure. Also, using the conventional control means,
Since the posture of the package placed obliquely is corrected only by controlling the speed of the conveyor, the posture of the package can be corrected at low cost without manufacturing other members. (Claim 2) Since the posture of the package is corrected by continuously accelerating the moving speed section in which the pusher is delayed, the time required for the correction is shortened, which leads to a reduction in the cycle time of the machine.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view schematically showing an embodiment.

FIG. 2 is a sectional view taken along line AA.

FIG. 3 is a plan view around a product placement unit.

FIG. 4 is a side view of the same.

FIG. 5 is an operation diagram showing a state in which the posture of the packaged object is corrected.

FIG. 6 is an explanatory diagram showing an electrical configuration of a control unit.

FIG. 7 is a flowchart showing a series of operations.

[Explanation of symbols]

A: Stretch wrapping machine T: Tray W: Packaged material
DESCRIPTION OF SYMBOLS 1 ... Product mounting part 2 ... Carrying-in means 4 ... Film transfer means 5 ... Elevating means 6 ... Packaging means 21 ... Conveyor part 26 ... Pusher F ... Film

Claims (2)

(57) [Claims] 1. A packaging means for folding an edge portion of a film on a lower surface of an article to be packaged comprising a product and a tray on which the article is placed, a product placing section for placing the article to be packaged, and the article placing section Carrying means for carrying the packaged object placed under the packaging means below the packaging means, elevating means for pushing up the packaged substance carried below the packaging means above the packaging means, and transporting and stretching the film below the packaging means. And a film transporting means for holding the frame, the loading means comprises a conveyer section in which conveyers are juxtaposed at predetermined intervals coaxially and a pusher for pushing a packaged object on the upper surface of the conveyer is provided. The upper part of the product placing part is formed in a plurality of flat plates at a predetermined interval, and the conveyor is arranged within the above-mentioned interval so that the upper surface of the product placing part is higher than the upper surface of the conveyor. The object was placed and carried in by the carrying means In a stretch packaging machine that pushes up an article to be stretched and held on a stretched and held film and folds a film edge onto a lower surface of the article to be packed, the carrying-in means includes: a pusher, after passing through the article placement section, after passing through the article placement section; Stretch wrapping machine characterized by a slower moving speed. 2. The stretch wrapping machine according to claim 1, wherein the moving speed of the pusher while passing through the product placing portion is accelerated.