JP2005096797A - Stretch packaging machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stretch packaging machine capable of simplifying a structure thereof and performing stretch film packaging with excellent appearance irrespective of the kind of a commodity to be packaged even when the commodity is easily damaged such as vegetables and fruits, or either a flexible tray or a hard tray is used. <P>SOLUTION: The stretch packaging machine comprises a film holding mechanism 50, a lift mechanism 30, and a control unit 90. The film holding mechanism 50 holds a film fed to a packaging unit. The lift mechanism 30 projects a commodity T to be packaged against the film. The control unit 90 moves the film holding mechanism 50 synchronous with the timing at which the commodity projected against the film by the lift mechanism 30 is brought into contact with the film. The control unit 90 controls the movement of the film holding mechanism 50 according to the nature of the commodity T. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a packaging machine, and more particularly, to a stretch packaging machine that pushes up and wraps an article to be packaged from below a film fed to a packaging unit.

  2. Description of the Related Art Conventionally, an apparatus for packaging a product such as fresh food stored in a tray using foamed polystyrene with a stretch film is known as a stretch packaging machine. In this stretch wrapping machine, a stretch film having a predetermined width is cut into a predetermined length according to the size of the tray, and both side edges in the width direction of the film are held by a pair of upper and lower belt feeders. While transporting the film to the packaging unit, stretch film packaging is applied at the packaging unit. The packaging unit pushes up the product stored in the tray (hereinafter referred to as “packaged product”) against the film that has been fed out and is held in tension, and the packaged product is in close contact with the film. Fold the rim to the bottom of the package. Specifically, the left and right folding members fold the left and right portions of the peripheral portion of the film to the lower side of the package, the rear folding member folds the rear portion of the peripheral portion of the film to the lower side of the package, Then, the object to be packaged is pushed forward by a pusher, and the front portion of the peripheral edge of the film is relatively folded to the lower side of the object to be packaged. Thus, after wrapping a packaged article with a stretch film, the film folded under the packaged article is heat-sealed to complete packaging.

  In such a stretch wrapping machine, before pushing up the object to be packaged against the film being fed to the packaging part, the film is lifted by raising the push-up frame from the lower side toward this film and pushing up the film. Patent Document 1 describes what is expanded by a predetermined amount. In the stretch wrapping machine described in Patent Document 1, since the film is not directly pushed up by the package, the package is avoided from being crushed by the film. Furthermore, in this stretch wrapping machine, the dimensions of the push-up frame can be changed according to the dimensions of the article to be packaged.

JP-A-4-57711

However, in the stretch wrapping machine described in Patent Document 1, the push-up frame can be changed according to the dimensions of the article to be packaged, and thus the push-up frame has a very large and complicated structure. In addition to a mechanism for raising and lowering a lift mechanism that pushes up an object to be packaged against a film, a mechanism for raising and lowering a push-up frame is also required. As described above, in the stretch wrapping machine described in Patent Document 1, it is necessary to provide a dedicated push-up frame in order to stretch the film by a predetermined amount, so that the cost is increased, the apparatus is enlarged, and the structure is complicated. Had the problem of becoming.
Furthermore, in the stretch wrapping machine, it is desirable to perform stretch wrapping with a good appearance regardless of the type of the packaged object when the packaged object is pushed up against the film fed to the packaging unit.

  An object of the present invention is a stretch wrapping machine that pushes up and wraps an object to be packaged from below a film fed to a packaging part, and simplifies the structure, and the product is easily damaged such as fruits and vegetables. In addition, it is an object of the present invention to provide a stretch wrapping machine capable of performing stretch film wrapping with a good appearance regardless of the type of objects to be packaged, regardless of whether a soft tray or a hard tray is used.

  The stretch wrapping machine according to claim 1 is a stretch wrapping machine that pushes up and wraps an article to be packaged from below the film fed to the wrapping unit, and includes a holding unit, a lift mechanism, and a control unit. . The holding means holds the film fed to the packaging unit. The lift mechanism pushes the object to be packaged onto the film. The control means moves the holding means in synchronism with the timing at which an article to be packaged pushed up by the lift mechanism comes into contact with the film. And this control means controls the moving amount | distance of the said holding means according to the property of a to-be-packaged object.

  Here, the holding means for holding the film fed to the packaging unit is moved in synchronism with the timing at which the article to be packaged pushed up by the lift mechanism comes into contact with the film. Therefore, when the package is pushed up from below the tensioned film that has been fed out to the packaging section, it is possible to prevent the film tension on the package from becoming excessive, and the product may be damaged by the film tension. , Can prevent the tray from being damaged and the film from being torn.

  Here, this type of stretch wrapping machine often has holding means for holding the film during packaging. Therefore, here, the tension of the film is adjusted while suppressing an increase in cost by using the holding means without providing a dedicated push-up frame or the like.

In addition, since the amount of movement of the holding means is controlled according to the properties of the package, the film tension applied to the package is appropriately adjusted even when using fruits and vegetables or using a soft tray. It can be in a state. Therefore, it is possible to prevent the object to be packaged from being damaged by the tension of the film, and it is possible to perform stretch film packaging with a good appearance.
Here, even a relatively hard tray that is not weak may be easily deformed depending on the size of the tray, and, for example, if a tray that is hard and has a large size is used, an excessively large film may be used. Even if this type of tray is used, the amount of movement of the holding means is controlled according to the nature of the tray, so that the film tension is kept in an appropriate state. can do. Therefore, the package can be prevented from being damaged or the film is torn by the tension of the film, and the stretch packaging can be performed with good appearance.

  A stretch wrapping machine according to a second aspect is the stretch wrapping machine according to the first aspect, further comprising storage means for storing a movement amount in accordance with the property of the package. And a control means controls the movement amount of the said holding means according to the property of the package thing memorize | stored in the memory | storage means.

  Here, by storing an appropriate amount of movement in the storage means according to the nature of the packaged object, the packaged object is pushed up from the lower side of the film that has been fed to the packaging unit and held in tension. Thus, the tension of the film can be set to an appropriate state according to the properties of the object to be packaged, and the stretch packaging can be performed with good appearance.

  A stretch wrapping machine according to a third aspect is the stretch wrapping machine according to the first or second aspect, further comprising designation means for designating a property of an object to be packaged. And a control means controls the movement amount of the said holding means according to the property of the package designated by the designation means.

  Here, by specifying the property of the packaged object by the designation means, the tension of the film applied to the packaged object is increased when the packaged object is pushed up from the lower side of the film that has been drawn out and held in the packaging unit. It can be in an appropriate state according to the properties of the object, and can be stretch-wrapped with good appearance.

  A stretch wrapping machine according to a fourth aspect is the stretch wrapping machine according to any one of the first to third aspects, wherein the holding means is a pair of front and rear film clamps arranged before and after the packaging part. The control means moves at least one of the front and rear film clamps in a direction approaching the other.

  Here, since a pair of front and rear film clamps conventionally used in this type of stretch wrapping machine is used as the holding means, there is no need to provide a dedicated push-up frame for extending the film by a predetermined amount. Therefore, it is possible to prevent an increase in cost and size of the apparatus, and it is possible to avoid a complicated structure.

  A stretch wrapping machine according to a fifth aspect is the stretch wrapping machine according to any one of the first to third aspects, wherein the holding means is a pair of left and right film clamps arranged on the left and right of the packaging part. Then, the control means moves at least one of the left and right film clamps in a direction approaching the other.

In this type of stretch wrapping machine, a pair of left and right film clamps may be employed in addition to a pair of front and rear film clamps in order to improve the packaging finish. Here, since such left and right film clamps are used as the holding means, there is no need to provide a dedicated push-up frame for extending the film by a predetermined amount. Therefore, it is possible to prevent an increase in cost and size of the apparatus, and it is possible to avoid a complicated structure.
Here, when a pair of left and right film clamps are newly provided, such left and right film clamps have the function of improving the finished state of the packaging in addition to the function of adjusting the tension of the film. It functions more effectively than when a frame is provided.

  A stretch wrapping machine according to a sixth aspect is the stretch wrapping machine according to any one of the first to fifth aspects, wherein the control means is configured to control the holding means according to the properties of the package and the dimensions of the package. Control the amount of movement.

Even if the properties of the package (such as “soft”) are the same, the film tension appropriate for the package can vary depending on the dimensions of the package. Therefore, it is possible to adjust the film tension more finely by controlling the amount of movement in consideration of not only the properties of the packaged object but also the dimensions of the packaged object.
For example, if the tray size is small, the amount of movement will be increased to prevent the film from sagging, or if the tray size is large, the amount of movement will be reduced to cause the tray to be damaged or the film torn. Can be suppressed.
In this way, since the tension of the film can be in an appropriate state, it is possible to prevent the object to be packaged from being damaged or torn by the film tension, and to perform stretch film packaging with a good appearance. Can do.

  In the present invention, the amount of movement of the holding means is controlled in accordance with the properties of the packaged object, so in the case of fruits and vegetables, whether a soft tray is used or a hard tray is used The tension of the film applied to the object can be in an appropriate state. Therefore, it is possible to prevent the object to be packaged from being damaged by the tension of the film, and it is possible to perform stretch film packaging with a good appearance.

<Embodiment 1>
A stretch wrapping machine according to an embodiment of the present invention is shown in FIG. This wrapping machine pushes up a stretched film F that holds a product such as fresh food (hereinafter abbreviated as packaged product T) contained in a tray against tension, and the peripheral portion of the film F is packaged T. It is an apparatus which performs film packaging by folding in the lower side. This packaging machine has an ability to wrap 25 to 35 articles to be packaged T per minute. Moreover, this packaging machine has a weighing function in addition to the film packaging function.
In some cases, the product is packaged in a state where it is not accommodated in the tray.

<Overall outline of the device>
As shown in FIGS. 1 and 2, the packaging machine mainly includes a weighing-in mechanism 20, a lift mechanism 30, a film transport mechanism 40, a film holding mechanism 50, a folding mechanism 60, and a pushing mechanism 70 (FIG. 3). Reference) and a heating mechanism 80. The weighing-in mechanism 20 is provided in the central portion on the front side. An article T to be packaged that has been weighed by a weighing unit 120 (described later) of the weighing-in mechanism 20 is loaded into a loading unit 160 (described later) of the weighing-in mechanism 20, a lift mechanism 30, a film transport mechanism 40, a film holding mechanism 50, and a folding mechanism 60. By the push-in mechanism 70 and the heating mechanism 80, the stretch film F is overlapped while moving in the packaging machine. The overlapped article T to be wrapped is carried out to a take-out stand 99 located in the space above the weighing unit 120 of the weighing-in mechanism 20. When the operator presses the bottom surface of the overwrapped article T that has been carried out in this way against the heater roller 81, the stretch films F overlapping on the bottom surface of the article T are heat sealed together.

  In the packaging operation, the carry-in portion 160 of the weighing-in mechanism 20 conveys the article to be packaged T toward the back side, and the film conveyance mechanism 40 sends out the film F drawn from the film roll R forward (front side). The holding mechanism 50 stretches the film F, the lift mechanism 30 pushes the package T up to the film F, the folding mechanism 60 folds the peripheral edge of the film F below the package T, and the heating mechanism 80 Heat seal the lower film F of T.

  In addition, a display panel 94 made of a touch panel, a display operation unit 93 made up of operation keys 95 and the like are arranged in the upper right part of the front.

  In addition, the packaging machine includes a control unit 90 including a CPU 90a, a ROM 90b, a RAM 90c, a storage unit 90d (storage means), and the like. The control unit 90 controls the operation of each of the mechanisms 20, 30, 40, 50, 60, 70, 80, and the like, and sets the measured value indicating the weight of the package T measured by the weighing-in mechanism 20. Based on this, the price of the product is calculated, and the operation of the label printer 11 and the label issuing machine 12 (see FIG. 3) that prints the weight and price of the product on the label is controlled.

  Note that the film roll R used in the packaging machine is one in which stretch films F having a predetermined width are wound in multiple layers, and are arranged on the upper part of the packaging machine by a support mechanism (not shown). 1).

<Configuration of weighing-in mechanism>
The weighing-in mechanism 20 mainly includes a weighing unit 120 that measures a product and a loading unit 160 that loads the weighed article T to the back of the packaging machine for packaging. The weighing platform 121 of the weighing unit 120 that supports the bottom surface of the package T and the carry-in support table 161 (FIG. 1) of the carry-in unit 160 are both configured in a comb shape, and the carry-in support table 161 is vertically and vertically. They are arranged so that they do not interfere with each other when they move.

  On the weighing platform 121 in the weighing unit 120, an article to be packaged T placed manually from the front side is placed. The load of the article to be packaged T placed on the weighing platform 121 acts on the load cell 131. Based on the signal output from the load cell 131, the CPU 90a calculates the weight of the article T to be packaged placed on the weighing table 121 in consideration of the weight of the weighing table 121 and the like.

  As shown in FIGS. 6 to 9, the carry-in support table 161 in the carry-in unit 160 is configured to slide in the front-rear direction and the vertical direction.

  By rotation of a motor (not shown), the tip of the carry-in support base 161 moves in a generally rectangular shape as shown in FIGS. As a result, the article T to be packaged placed on the weighing platform 121 is lifted by the carry-in support table 161 moving from the lower side to the upper side of the weighing table 121 and conveyed toward the back side. The article T to be packaged placed on the carry-in support table 161 moved to the back side is scooped up from the carry-in support table 161 by the support member 33 of the lift mechanism 30 described later, and is transferred onto the support member 33 of the lift mechanism 30. .

<Configuration of lift mechanism>
The lift mechanism 30 is a mechanism for holding the bottom surface of the article to be packaged T and moving the article to be packaged T upward, a support base 31, a plurality of support columns 32 fixed on the support base 31, And a support member 33 that is supported by the upper end portion of each support column 32 and receives the bottom surface of the package T. In addition, the lift mechanism 30 includes a motor and a link mechanism or an electric ball screw mechanism (not shown) for moving the support base 31 up and down below the support base 31.

  As shown in FIG. 2, seven support pillars 32 and support members 33 of the lift mechanism 30 are provided at intervals in the left-right direction. The support pillar 32 and the support member 33 enter the comb-like space of the carry-in support table 161 when scooping up the package T from the carry-in support table 161 of the carry-in unit 160 of the weighing-in mechanism 20. 161 and the support member 33 do not interfere with each other.

  The support member 33 of the lift mechanism 30 is supported by a spring so that it can fall inward in the left-right direction, and is supported by another spring so that it can also fall on the front side.

  Further, in the space above the lift mechanism 30, when the package T is pushed up by the lift mechanism 30 and stopped by the film F, a holding member that serves to prevent the package T from breaking down and falling over (see FIG. (Not shown) is arranged.

<Configuration of film transport mechanism>
The film transport mechanism 40 is a mechanism that transports the film F cut to a predetermined size above the article T to be packaged supported by the lift mechanism 30 and holds the film F in tension by the film holding mechanism 50. The film transport mechanism 40 mainly includes a support mechanism (not shown) that rotatably supports the film roll R, a front clamp 54 that holds the front end of the film F fed from the film roll R, and a front clamp 54. And a front clamp moving mechanism that moves back and forth. The front clamp moving mechanism includes a front clamp forward / backward movement motor, a belt mechanism, a front clamp support member, and the like (not shown). Here, the front clamp 54 moves back and forth by operating the front clamp forward / backward movement motor. The front clamp 54 holds or releases the front end of the film F by turning on / off a front clamp solenoid switch (not shown).

  When a command to convey the film F is issued from the control unit 90, the front clamp 54 moves rearward and grasps the leading end of the film F that is fed from the film roll R and reaches the vicinity of the rear clamp 53. Then, the front clamp 54 moves forward with the front end of the film F being held, so that the film F is positioned above the lift mechanism 30.

<Configuration of film holding mechanism>
The film holding mechanism 50 mainly includes a front clamp 54 and a front clamp moving mechanism that are also components of the film transport mechanism 40, a rear clamp 53 and a rear clamp moving mechanism, a left clamp 51, a right clamp 52, and a film to be described later. It is comprised from the left-right pushing members 71 and 72 which are the components of the pushing mechanism 70, and the left-right pushing member moving mechanism (not shown).

  The rear clamp 53 holds or releases the rear end of the film F by turning on or off a not-shown rear clamp solenoid switch, and moves back and forth by a rear clamp moving mechanism. The rear clamp moving mechanism includes a rear clamp forward / backward movement motor, a belt mechanism, a rear clamp support member, and the like (not shown).

  As shown in FIG. 10, the left clamp 51 and the right clamp 52 are provided below left and right pressing members 71 and 72, which will be described later, and the film F is sandwiched between the left and right pressing members 71 and 72. Hold. That is, the left and right clamps 51 and 52 hold the film F by moving up and coming into contact with the left and right pressing members 71 and 72, and holding the film F by moving down and away from the left and right pressing members 71 and 72. Is released. Accordingly, in order to move the left clamp 51 and the right clamp 52 up and down, a left clamp up and down motor and a right clamp up and down motor are provided (not shown). When these motors operate, the left clamp support base 51b and the right clamp support base 52b supporting the left clamp 51 and the right clamp 52 move up and down.

  The left clamp 51 and the right clamp 52 are supported by a left clamp support base 51b and a right clamp support base 52b so as to be movable left and right by a predetermined distance. Then, the left clamp 51 and the right clamp 52 can slightly move up and down with respect to the left clamp support base 51b and the right clamp support base 52b so that the left clamp 51 and the right clamp 52 do not draw an arcuate locus due to the left-right movement. It is configured as follows. Therefore, when the left and right push members 71 and 72 move to the left and right in a state where the left and right clamps 51 and 52 are pressed against the left and right push members 71 and 72 from below, the left and right clamps 51 and 52 follow the movement. That is, the left and right pushing member moving mechanism that moves the left and right pushing members 71 and 72 to the left and right also serves to move the left clamp 51 and the right clamp 52 to the left and right.

  The film holding mechanism 50 plays a role of holding the periphery of the film F when the article to be packaged T is pushed up by the lift mechanism 30, and immediately before the article to be packaged T is pushed up, the film F Perform the pre-stretch operation to make the tension. By this pre-stretching operation, the clamps 51, 52, 53, 54 holding the peripheral portion of the film F are horizontally moved outward, and the film F is stretched by a predetermined amount.

  Further, the film holding mechanism 50 performs an operation (returning operation) of loosening the tension of the film F when the package T is pushed up by the lift mechanism 30. By this returning operation, the clamps 51, 52, 53, 54 holding the peripheral portion of the film F move horizontally inward, and the tension of the film F by the pre-stretching operation is a property of the packaged object as described later. The amount is relaxed according to the amount.

<Configuration of film push-in mechanism>
The film pressing mechanism 60 includes left and right pressing members 71 and 72 and a left and right pressing member moving mechanism that moves the pressing members 71 and 72 to the left and right. The left and right pushing member moving mechanism includes a film pushing motor, a belt mechanism, a support member that supports the left and right pushing members 71 and 72 (not shown), and the like. The film pushing motor is actuated by a command from the control unit 90 and moves the left and right pushing members 71 and 72 to the left and right.

  Further, the left and right pushing members 71 and 72 can hold the film F by sandwiching the film F between the left and right clamps 51 and 52, and act as a part of the clamp. Here, elastic bodies 51 a, 52 a, 71 a, 72 a are attached to the upper surfaces of the left and right clamps 51, 52 and the lower surfaces of the left and right pushing members 71, 72 in order to strengthen this clamping action. These elastic bodies 51a, 52a, 71a, 72a are formed long in the front-rear direction. As shown in FIG. 10B, when the left (right) clamp 51 (52) moves upward and comes into close contact with the left (right) push-in member 71 (72), the elasticity of the left (right) clamp 51 (52). The body 51a (52a) is in close contact with the elastic body 71a (72a) of the left (right) pushing member 71 (72), and the movement of the film F in the left-right direction is strongly restricted. Thus, the holding degree which hold | maintains the film F with the left-right clamps 51 and 52 and the left-right pushing members 71 and 72 is strengthened by presence of the elastic bodies 51a, 52a, 71a, and 72a.

<Configuration of film left / right folding mechanism>
The film left / right folding mechanism 60 mainly includes left and right folding plates 64 and 65 and a left and right folding motor (not shown) for moving the left and right folding plates 64 and 65 to the left and right. The left and right folding motor moves the folding plates 64 and 65 to the left and right via a belt mechanism and a support member that supports the folding plates 64 and 65.
The left and right folding plates 64 and 65 are disposed above the left and right pushing members 71 and 72, and support the bottom of the package T when the film is folded by the rear folding plate 71, the front folding rod 68, and the pusher 69 described later.

<Configuration of the film back-and-forth folding mechanism>
As shown in FIGS. 1 and 2, the film front / rear folding mechanism mainly includes a rear folding plate 67, a front folding bar 68, and a pusher 69.

  The rear folding plate 67 can be moved horizontally by a motor and a timing belt (not shown), and enters the lower side of the tray with a slight delay from the left and right folding plates 64 and 65.

  The front folding bar 68 has the front edge of the film F on the lower side of the package T when the package T is moved to the front side by the pusher 69 that pushes the package T toward the take-out base 99. It is arranged to be folded.

  The pusher 69 is moved back and forth by a driving device (not shown). After the left and right end portions and the rear end portion of the film F are folded below the package T by the left and right folding plates 64 and 65 and the rear folding plate 67, the pusher 69 moves to the front side and the package T Is pushed out to the take-out stand 99.

<Configuration of heating mechanism>
The heating mechanism 80 is disposed in front of the front folding rod 68 and mainly includes a heating roller 81 and free rollers 82 disposed in front of and behind the heating roller 81. The heating roller 81 is formed in a cylindrical shape, and a cylindrical electric heater is inserted therein. This heater is a so-called cartridge heater and is not in contact with the heating roller 81. An electrode is provided at one end of the heater, and the heating coil in the heater generates heat when energized from this electrode.

<Configuration of control unit>
The control unit 90 is configured as shown in FIG. 3, and controls each operation of each mechanism 20, 30, 40, 50, 60, 70, 80, and the like. The control unit 90 includes a CPU 90a, a ROM 90b, a RAM 90c, a storage unit 90d (storage means), and the like.

  The storage unit 90d is realized by a storage device such as a hard disk. The storage unit 90d includes various control programs, a product master 91 that is a database that stores information about products to be processed such as packaging, and a tray master 92 that is a database about trays. Mainly stored (see FIG. 3).

  As shown in FIG. 4, the product master 91 includes a product call No. Product name, unit price, tray no. Such data is stored.

  In addition, as shown in FIG. The tray width, depth, height, tray weight, film left / right pre-stretch amount, film front / rear pre-stretch amount, left / right clamp movement amount (left / right clamp return amount) and Data such as the amount of movement of the front / rear clamp (front / rear clamp return amount) is stored.

  In the packaging machine of this embodiment, the movement amount of the holding means according to the property of the article to be packaged T, which is the article to be packaged, is stored in the tray master 92 as the left and right clamp return amount and the front and rear clamp return amount.

<Display operation section>
The display operation unit 93 includes a display panel 94 including a touch panel, operation keys 95, and the like. Various data can be registered in the merchandise master 91 and the tray master 92 by the operator performing a predetermined operation.
In addition, call No. Is entered from the merchandise master 91. The data of the product corresponding to is called up and displayed on the display panel 94.

<Operation outline of packaging machine>
Next, the operation of the packaging machine having the above configuration will be described with reference to FIGS.

In this apparatus, first, an operator calls a call number for a product to be packaged. Is input from the display operation unit 93. The CPU 90a then enters the input call number. Based on the above, the data stored in the product master 91 is searched. And if there exists an applicable product, the data regarding the product will be called from the product master 91.
At this time, the call No. Stored in correspondence with the tray No. Based on the data, data related to the tray used for the product (data such as film left / right pre-stretch amount, film front / rear pre-stretch amount, left / right clamp return amount, front / rear clamp return amount, tray weight, etc.) is called from the tray master 92. .

  Next, the operator places the article to be packaged T on the weighing platform 121 of the weighing-in mechanism 20 (see FIG. 6). When the CPU 90a confirms that the weighing value is stable and the weighing is completed, the CPU 90a sends a command to the motor of the carry-in section 160 of the weighing-in mechanism 20 to rotate the carry-in support table 161 in a rectangular manner to place the package T on the weighing table. It is carried in from 121 to the upper space of the support member 33 of the lift mechanism 30 (see FIGS. 7 and 8).

  As shown in FIG. 8, when the article to be packaged T moves to the space above the support member 33, the lift mechanism 30 is raised so that the lift mechanism 30 receives the article to be packaged T from the carry-in support table 161 (FIG. 8). 11 (a)).

On the other hand, as shown in FIG. 11A, when the film F is transported above the lift mechanism 30 by the film transport mechanism 40, the left and right clamps 51, 52 are lifted and between the left and right pushing members 71, 72. Hold the left and right parts of the film F. At this time, the front and rear portions of the film F are also held by the front and rear clamps 53 and 54.
Next, the left and right pushing members 71 and 72 and the left and right clamps 51 and 52 that follow them are opened outward, and the film F is prestretched in the left and right direction (see FIG. 11B). At this time, the film F is also prestretched in the front-rear direction. Here, the pre-stretch in the left-right direction and the front-rear direction is performed based on each pre-stretch amount that is stored in advance in the tray master for each tray and called when starting packaging of the product. Thus, by prestretching the film in the front-rear direction and the left-right direction, wrinkles of the film can be eliminated and the amount of film used can be suppressed. In addition, since prestretching is performed based on the amount stored in advance for each tray, it is possible to perform prestretching by an appropriate amount according to the size and properties of the package.

Next, when the lift mechanism 30 continues to rise further toward the film F, the article to be packaged T comes into contact with the film F.
At this time, the left and right clamps and the front and rear clamps are moved in synchronism with the timing when the article to be packaged T comes into contact with the film. Preferably, immediately after the article to be packaged T comes into contact with the film, the pair of left and right clamps holding the left and right ends of the film F are moved toward each other (inner side) and the pair of holding the front and rear ends of the film F is held. The front and rear clamps are moved toward each other (see FIG. 11C). By doing so, it is possible to prevent the film tension applied to the packaged object from becoming excessive when the packaged object T is pushed up to the film F, the product is damaged by the film tension, the tray is damaged, The film can be prevented from being torn.

  Here, in the packaging machine in this embodiment, the movement amounts of the left and right clamps and the front and rear clamps are controlled in accordance with the properties of the packaged items. Specifically, the left and right clamp return amounts and the front and rear clamp return amounts stored in advance in the storage unit 90d according to the nature of the tray are called, and the left and right clamps and the front and rear clamps that hold the film F based on these return amounts are respectively called Move. By doing so, it is possible to more appropriately suppress the tension of the film applied to the packaged object when the packaged object is pushed up to the film F according to the property of the packaged object. Can be prevented from being damaged, the tray can be damaged, and the film can be torn.

  When the lift mechanism 30 further raises the package T, the film F is pushed up by the package T (see FIG. 9). At this time, the article to be packaged T is covered with the film F at the top and sides.

  In this state, the left and right folding plates 64 and 65 first enter the inner side, and the left and right pressing members 71 and 72 and the rear folding plate 67 also enter the inner side with a slight delay (see FIG. 12). The left and right folding plates 64 and 65 stop moving when they enter the position where they can support the bottom of the package T (see FIG. 11D). On the other hand, the left and right pushing members 71 and 72 and the left and right clamps 51 and 52 that follow them are located on the inner side following the left and right folding plates 64 and 65 so that excessive tension does not act on the film F due to the movement of the left and right folding plates 64 and 65. The left and right clamps 51 and 52 are lowered at an appropriate position to release the holding of the left and right portions of the film F (see FIG. 11D).

  Even after releasing the holding of the left and right portions of the film F, the left and right pushing members 71 and 72 continue to move inward to push the film F toward the bottom side of the package T, and finally from the left and right folding plates 64 and 65. It moves to the inside and stops (see FIG. 11E).

  When the left and right end portions and the rear end portion of the film F are folded below the package T by the left and right folding plates 64 and 65 and the rear folding plate 67, the pusher 69 moves to the front side and the packaged material. T is pushed out to the take-out base 99 (see FIGS. 13 and 14). At this time, the front end portion of the film F is folded below the package T by the front folding rod 68. And when it is carried out to the taking-out stand 99, the to-be-packaged object T will be overlapped and the edge part of the film F will be in the state overlapped in the bottom face.

  Further, when the pusher 69 is pushing the article to be packaged T, the carry-in support base 161 of the carry-in portion 160 of the weighing-in carry-in mechanism 20 returns to the initial position, and the lift mechanism 30 lowers the support base 31 and the support member 33. Prepare for the next package. Therefore, as shown in FIG. 13, the operator can place the article T to be packaged next to the article T to be packaged on the weighing platform 121 of the weighing-in mechanism 20 to start the weighing operation. .

  As shown in FIG. 14, the bottom surface (the portion where the end portion of the film F is folded) is pressed against the heater roller 81 by the operator's hand. Thereby, the film F which overlaps in the bottom face of the to-be-packaged object T is heat-sealed mutually, and packaging is completed.

  When processing including labeling is selected, the price or weight of the product calculated based on the measured value is printed on the label by the label printer 11. The label is affixed to the packaged object T (on the film F) by the label issuing machine 12 or by the operator's hand.

<Characteristics of packaging machine of this embodiment>
(1)
In this packaging machine, before the to-be-packaged object T is pushed up by the lift mechanism 30, the left and right pushing members 71 and 72 and the left and right clamps 51 and 52 that follow them open to the outside, and the film F moves in the left and right direction. Pre-stretching (see FIG. 11B). At this time, the film F is also prestretched in the front-rear direction.

  Thereby, the to-be-packaged object T can be packaged neatly without wrinkles on the film, and the amount of film used can be suppressed. Moreover, since the pre-stretching in the left-right direction and the front-rear direction is performed based on the amount stored in advance in the tray master for each tray, the pre-stretching can be performed by an appropriate amount according to the size and properties of the package. it can.

(2)
In this packaging machine, the left and right clamps 51 and 52 and the front and rear clamps 53 and 54 as holding means for holding the film fed to the packaging unit are placed at a timing when an article to be packaged pushed up by the lift mechanism 30 comes into contact with the film. Move in sync. Specifically, immediately after the article to be packaged comes into contact with the film, the pair of left and right clamps 51 and 52 are moved toward each other (inward) based on the amount of movement, and the pair of front and rear clamps 53 and 54 are moved to each other. Move it closer.

  As a result, it is possible to prevent the tension of the film on the package from becoming excessive when the package is pushed up from the lower side of the film that has been drawn out and held in the packaging unit, and the product is damaged by the film tension. It is possible to prevent the tray from being damaged or the film from being torn.

Furthermore, here, in order to prevent the tension of the film from becoming excessive, it is used to improve the front and rear clamps 53 and 54 conventionally used in this type of stretch wrapping machine and the finished state of the packaging. Left and right clamps are used. For this reason, it is not necessary to provide a dedicated push-up frame or the like for extending the film by a predetermined amount. Therefore, adjustment of the film tension can be realized while suppressing an increase in cost, an increase in size of the apparatus, and a complicated structure.
Here, the left and right clamps 53 and 54 function more effectively than the case where a dedicated push-up frame is provided, in addition to the effect of adjusting the tension of the film, as well as the finished state of the packaging.

(3)
In this packaging machine, the amount of movement of the left and right films 51 and 52 and the front and rear clamps 53 and 54 as holding means for holding the film fed to the packaging unit is controlled according to the properties of the package. Specifically, the right / left clamp return amount and the front / rear clamp return amount stored in advance in the storage unit 90d according to the properties of the package object are called, and immediately after the package object T comes into contact with the film, the return amount is set. Based on this, the pair of left and right clamps 51 and 52 are moved in a direction (inward) approaching each other, and the pair of front and rear clamps 53 and 54 are moved in a direction approaching each other.

Thereby, even if it is a case of fruits and vegetables or a case where a soft tray is used, the tension of the film concerning a package can be made into an appropriate state. Therefore, it is possible to prevent the object to be packaged from being damaged by the tension of the film, and it is possible to perform stretch film packaging with a good appearance.
Here, even a relatively hard tray that is not weak may be easily deformed depending on the size of the tray, and, for example, if a tray that is hard and has a large size is used, the film may be excessive. Even if this type of tray is used, the amount of movement of the holding means is controlled according to the nature of the tray so that the film tension is in an appropriate state. be able to. Therefore, even when packaging any type of package, it is possible to prevent the package from being damaged or torn by the tension of the film, and to perform stretch packaging with a good appearance. .

(4)
In this packaging machine, the amount of movement of the left and right clamps and the front and rear clamps is controlled according to the properties of the tray in synchronization with the timing when the article T to be packaged pushed up by the lift mechanism 30 contacts the film. Timing is constant regardless of tray type.

  That is, the timing of moving the left and right clamps and the front and rear clamps is matched to the timing of contacting the film regardless of the width dimension, depth dimension, and tray hardness of the tray, so that timing control of each part of the apparatus is simplified.

(5)
In this packaging machine, the left and right folding plates 64 and 65 enter the inner side ahead of the left and right pushing members 71 and 72 and the rear folding plate 67 and enter the position where the bottom of the package T can be supported. By the way, the movement is stopped. That is, the left and right folding plates 64 and 65 support the bottom of the package T during the film folding operation by the rear folding plate 71, the front folding rod 68 and the pusher 69. Thereby, in the initial stage of the film folding operation, the role of supporting the bottom of the package T is baton-touched from the lift mechanism to the left and right folding plates 64 and 65, so that the lift can be performed without waiting for the film folding operation to be completed. It is possible to lower the mechanism.

(6)
In this packaging machine, a rear folding plate 67 is disposed below the left and right folding plates 64 and 65, and left and right pushing members 71 and 72 are further provided below the rear folding plate 67. Since the left and right pushing members 71 and 72 push the film inward from the packaged object T so as to prevent the film from spreading outside the packaged object T during the film folding operation, as described above. Regardless of the positional relationship between the left and right folding plates 64 and 65 and the rear folding plate 67, the packaging can be performed cleanly.

(7)
In this packaging machine, the left and right pushing members 71 and 72 can hold the film F by sandwiching the film F between the left clamp 51 and the right clamp 52. When the left and right push members 71 and 72 move to the left and right in a state where the left clamp 51 and the right clamp 52 are pressed against the left and right push members 71 and 72 from below, the left clamp 51 and the right clamp 52 follow the movement. . Therefore, the left and right pushing member moving mechanism for moving the left and right pushing members 71 and 72 to the left and right also serves to move the left clamp 51 and the right clamp 52 to the left and right, so that it is not necessary to provide a separate moving mechanism and the cost is reduced. Can be suppressed.

(8)
In this packaging machine, the left and right pushing members 71 and 72 and the left and right clamps 51 and 52 following them move inward following the left and right folding plates 64 and 65, and the left and right clamps 51 and 52 are moved at appropriate positions. The film F is lowered to release the left and right portions of the film F (see FIG. 11D). As described above, the left and right push-in members 71 and 72 and the left and right clamps 51 and 52 are moved inward at the same time as the left and right folding plates 64 and 65 are moved inward, and finally the left and right clamps 51 are finally moved. , 52 is released to release the holding of the left and right portions of the film, so that an appropriate tension is applied to the film, and the movement of the left and right folding plates 64 and 65 prevents the excessive tension from acting on the film F. it can.

(9)
In the above embodiment, in order to move the clamp based on the clamp return amount stored in the tray master 92, in addition to using the stored return amount as the clamp movement amount, the stored return amount is used. The use of an amount obtained by adding other conditions (for example, the height of the product) to the amount is also included.

<Other embodiments>
(A)
In the above embodiment, the amount of movement of the clamp is controlled according to the property of the package, but the clamp 51, depending on the property of the package and the dimensions (width, depth, height) of the package, It is also possible to control the movement amounts of 52, 53, and 54.
Here, even if the properties (such as “soft”) of the packaged object are the same, the film tension appropriate for the packaged product may vary depending on the dimensions of the packaged product. Therefore, it is possible to adjust the film tension more finely by controlling the amount of movement in consideration of not only the properties of the packaged object but also the dimensions of the packaged object.
For example, if the tray size is small, the amount of movement is increased to prevent the film from sagging, and if the tray size is large, the amount of movement is reduced to prevent the tray from being damaged or the film from tearing. Can be suppressed.
Thus, since the tension of the film can be in an appropriate state, it is possible to prevent the tray from being damaged or torn by the tension of the film, and it is possible to perform stretch film packaging with a good appearance. .

(B)
In the above embodiment, the tray number of the tray master 92 is changed. The movement of the clamp is controlled according to the nature of the tray by storing the clamp return amount in correspondence with the item. It may be provided in the section 93 and the operator may designate the nature of the tray by operating this designation key. In this case, the reference return amount of the clamp is stored, and the movement amount according to the property of the package is obtained by adding a value according to the property of the package to the reference return amount. Alternatively, for example, the clamp return amount in the case of a hard tray is stored as a reference return amount, and in the case of a soft tray, a value corresponding to the property is added to the reference return amount to obtain the movement amount. You may do it.

(C)
In the above-described embodiment, the film pre-stretching and returning operation are performed for both the left and right clamps and the front and rear clamps, but only one of the left and right clamps or the front and rear clamps may be performed. Further, it is not always necessary to pre-stretch the film.

(D)
In the above embodiment, when performing the film pre-stretching and returning operation, each of the pair of clamps is operated, but only the other clamp may be operated while one clamp is stopped. That is, if the distance between the pair of clamps is widened, the film is pre-stretched. If the distance between the pair of clamps is narrowed, the film tension is eased.

(E)
In the above embodiment, the clamp return amount is stored for each type of tray. However, the present invention is not limited to this, and may be stored for each type of product. For example, trays may not be used when packaging fruits and vegetables. Many of such so-called non-tray products are easily damaged, and it is not preferable that the tension of the film to be packaged is excessive as in the case of the soft tray. Therefore, if a clamp return amount is set for each type of product, even in the case of a non-tray product, an appropriate film tension can be set according to the property. Note that the clamp return amount in this case is the product call number. Can be stored in the merchandise master, or even in the case of non-tray, the clamp return amount can be stored in the tray master by using the tray master for convenience.

(F)
In the above embodiment, the holding means (clamp) is moved in synchronism with the timing at which the article to be packaged pushed up by the lift mechanism comes into contact with the film, but the folding mechanism moves the peripheral part of the film to the article to be packaged. It is also possible to move the holding means (clamp) when folding it down. By doing so, it is possible to suppress an excessive tension of the film applied to the package object when the film is folded. Here, it is also possible to control the movement amount of the clamp at the time of folding according to the property of the package.

  In the stretch wrapping machine according to the present invention, since the holding means is moved based on the amount of movement according to the property of the packaged object, in the case of fruits and vegetables, either when using a soft tray or when using a hard tray Even if there is, the tension of the film applied to the package can be in an appropriate state, the package tension can be prevented from being damaged by the tension of the film, and the stretch film packaging can be performed nicely It is useful as a required stretch packaging machine.

It is a schematic side view of a stretch wrapping machine. It is an II-II arrow line view of FIG. It is a control block diagram of a stretch wrapping machine. It is a figure which shows an example of the data memorize | stored in the goods master of the memory | storage part. It is a figure which shows an example of the data memorize | stored in the tray master of a memory | storage part. It is a schematic side view which shows the packaging operation | movement of a stretch wrapping machine. It is a schematic side view which shows the packaging operation | movement of a stretch wrapping machine. It is a schematic side view which shows the packaging operation | movement of a stretch wrapping machine. It is a schematic side view which shows the packaging operation | movement of a stretch wrapping machine. It is a schematic front view which shows the packaging operation | movement of a stretch wrapping machine. It is a figure which shows the right-and-left folding operation. It is a schematic side view which shows the packaging operation | movement of a stretch wrapping machine. It is a schematic side view which shows the packaging operation | movement of a stretch wrapping machine. It is a schematic side view which shows the packaging operation | movement of a stretch wrapping machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 Metering mechanism 30 Lift mechanism 40 Film conveyance mechanism 50 Film holding mechanism 51,52 Left and right clamp 60 Folding mechanism 64,65 Left and right folding plate 67 Rear folding plate 68 Front folding rod 69 Pusher 70 Film pushing mechanism 71,72 Left and right pushing member F Stretch film (film)
T Package

Claims (6)

It is a stretch wrapping machine that pushes up and wraps an object to be packaged from below the film fed to the packaging part,
Holding means for holding the film fed to the packaging part;
A lift mechanism for pushing the article to be packaged onto the film;
Control means for moving the holding means in synchronism with the timing when the article to be packaged pushed up by the lift mechanism comes into contact with the film;
The control means further controls the movement amount of the holding means according to the property of the packaged object.
Stretch wrapping machine. Further comprising storage means for storing the amount of movement according to the nature of the packaged item,
The control means controls the amount of movement of the holding means according to the property of the article to be packaged stored in the storage means.
The stretch wrapping machine according to claim 1. Further comprising a designation means for designating a property of the package;
The control means controls the amount of movement of the holding means according to the property of the package designated by the designation means;
The stretch wrapping machine according to claim 1 or 2. The holding means is a pair of front and rear film clamps arranged before and after the packaging part,
The control means moves at least one of the front and rear film clamps in a direction approaching the other,
The stretch wrapping machine according to any one of claims 1 to 3. The holding means is a pair of left and right film clamps arranged on the left and right of the packaging part,
The control means moves at least one of the left and right film clamps in a direction approaching the other,
The stretch wrapping machine according to any one of claims 1 to 3. The control means controls the amount of movement of the holding means according to the nature of the package and the dimensions of the package;
The stretch wrapping machine according to any one of claims 1 to 5.

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