JPH06270912A - Wrapping apparatus - Google Patents

Abstract

PURPOSE:To heat-seal a product without being significantly limited by a height and shape of the product in a wrapping apparatus for automatically applying a heat seal to a stretch film. CONSTITUTION:At a wrapping station S, a film F is folded onto a bottom of a tray T by a pair of right and left folding plates 15, 15, a rear folding plate 16 and a front folding member 17. A driving motor is driven along with advance of a pusher 13, and a pressing roller 41 rotates along a direction of a product M carried. Thus the product M passes over a heating roller 23. At this time since the pressing roller 41 applies weight of the pressing roller 41 and a contact means 31 onto the product M, a bottom Tb of the product is pushed against the heating roller 23 to facilitate heat-sealing of the film F. The pressing roller 41 is shakably provided around a horizontal axial core.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packaging device, and more particularly, to a film heat sealing device in a packaging device in which a side edge portion of a film covering an upper portion of a tray is folded to a bottom surface side of the tray for stretch packaging. It is a thing.

[0002]

2. Description of the Related Art There is known a packaging apparatus for packaging a product such as a fresh food product placed on a polystyrene foam tray with a stretch film together with the tray. In this type of packaging device, the side edge of the film is clamped to hold the film in tension at the wrap station, and the tray on which the product is placed is pushed up to the lap station and brought into close contact with the product or the upper surface of the tray. The front and rear and left and right side edges of the film are folded onto the bottom side of the tray by folding members, and the product is packaged together with the tray in the film. An example of this folding method is shown in FIG.

As shown in FIG. 11, the film F is held in a state in which the front and rear side edge portions Ff and Fb are clamped by a clamp means (not shown) to be tensioned. In this state, the pair of left and right folding plates 15, 15 are
Left and right directions L and R along the bottom surface Tb of the tray T, respectively.
To the side edge portions Fl, F of the film F.
r is folded into the bottom surface Tb side of the tray T. At the same time, the front and rear side edge portions Ff and Fb of the film F are released from the clamps, and the rear folding plate 16 advances to the front Fo, so that the rear side edge portion Fb of the film F is folded to the bottom surface Tb side of the tray T. Be done. Further, the tray T is a pusher 13 (see FIG.
2), the front side edge Ff of the film F is folded toward the bottom surface Tb of the tray T by the front folding member 17. Thus
As will be described below, the folded portions Fa folded on the bottom surface Tb side of the tray T are welded to each other and heat-sealed, and the packaged state is maintained.

In FIG. 12A, the package A is pushed forward by the pressing roller 41A while the bottom surface Tb is pressed against the heating roller 51 of the lower sealing device 50. At this time, the folded portions Fa of the film F are heated during the transfer and are welded to each other by the pressing force of the pressing roller 41A. The welding of the film F is
Because the film F is not completely melted,
It is necessary to slightly press the bottom surface Tb against the heating roller 51.

[0005]

By the way, since the height of the package A changes variously, it is necessary to support the pressing roller 41A so that it can move up and down. However, in the state where the pressing roller 41A is rotatably supported, Moreover, it is not easy to give a large stroke up and down. Therefore, the height of the package A that can be heat-sealed is limited. Particularly, in the case where the pressing roller 41A is rotationally driven in the circumferential direction, it becomes difficult to support the pressing roller 41A so as to be movable up and down with a large stroke.

Further, in the case of a product M such as sashimi, FIG.
As shown in (b), since the rigid bridge Mb is provided in the center, the pressing roller 41A presses only a part of the center of the package A, so that the conveyance becomes unstable and a good sealing state is obtained. It may not be possible.

When the operator takes out the package A without the pressing roller 41A, the bottom surface Tb of the package A is removed.
Is also pressed against the heating roller 51. However, such a method not only has poor workability but also hinders automation.

The present invention has been made in view of the above conventional problems, and in a packaging device for automatically heat-sealing a stretch film, the heat-sealing can be performed without being limited to the height or shape of the product. The purpose is to

[0009]

In order to achieve the above object, the present invention has a pressing roller for pressing the bottom surface side of a tray against a sealing device around a horizontal axis centered on both sides of a package transfer path. It is swingably supported by and is provided symmetrically with respect to each other.

[0010]

According to the present invention, since the pressing roller is swingably provided around the horizontal axis, it is not necessary to largely move the support portion supporting the pressing roller even when the product is tall. In addition, since the swing angle of the support portion only increases, the range of heights of products that can be pressed widens. Also,
Since a pair of pressing rollers are provided, the product is pressed symmetrically from the left and right, so that the product is conveyed in a stable state.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the layout of the packaging weighing device and the flow of the tray T. In FIG. 1, the tray T on which the product M is placed is in an unwrapped state, and the supply conveyor device 2
Thus, it is intermittently transferred onto the lifter 10.

As shown in FIG. 2, a packaging mechanism 11 is provided above the lifter 10. The packaging mechanism 11 packages the product M together with the tray T with the film F at the upper wrap station S. The lap station S
A sealing device 20 is disposed in front of Fo. The sealing device 20 heat seals the folded portions Fa (FIG. 12) of the film F folded on the bottom surface Tb of the tray T. The heat-sealed packaged product A of FIG. 1B is transferred onto the weighing conveyor 4 by the direction changing conveyor 3, and the weight of the product M is weighed while being transferred by the weighing conveyor 4. After that, the packaged product A is transferred to the lower part of the label sticking machine 5 by a conveyor, and then a label having a product code, a weight and the like printed thereon is stuck.

Next, each of the above components will be described in detail. In FIG. 2, the lifter 10 is arranged immediately below the lap station S and is vertically movable. When the tray T is carried in from the supply conveyor device 2, the lifter 10 moves up by a certain stroke to lift the tray T, and presses the tray T against the lower surface of the film F held in tension in the wrap station S.

On the other hand, the film F is preliminarily supplied to the lap station S in a state of being sandwiched by the film feeder 6, and when the product M is pushed up by the lifter 10, the film F comes into close contact with the upper surface of the product M. . In this state, the packaging mechanism 11 attaches the front, rear, left, and right side edges of the film F to the bottom surface side T of the tray T, as will be described below.
The tray T is packaged together with the product M by folding it in b.

FIG. 3 is a schematic perspective view of the lap station S. The packaging mechanism 11 includes a pair of left and right folding plates (folding members) 15, 15, a rear folding plate (folding member) 16, and a round bar-shaped front folding member 17. Left and right folding board 1
5 and 15 move forward and backward in the left and right directions L and R. On the other hand, the rear folding plate 16 moves back and forth in the front and rear directions Fo and B. The left and right folding plates 15 and the rear folding plate 16 move forward and backward along the bottom surface Tb of the tray T to fold the film F into the bottom surface side of the tray T. The pusher 13 is driven at a predetermined timing slightly behind the rear folding plate 16, and the pusher 13 is driven.
The front folding member 17 folds the side edge portion of the front Fo of the film F into the bottom surface side Tb of the tray T in accordance with the discharging operation of the product M by. Each film feeder 6 in FIG. 2 is provided with a pair of conveyor belts 61 and 62, and one film feeder 6 is configured to move left and right according to the width of the film F. The feeder 6 may be configured to move left and right.

The lap station S shown in FIG. 3 is provided with an abutting member 31 which constitutes a part of the posture stabilizing device 30. The contact members 31 are provided in a pair on the left and right, and contact the upper surface of the product M pushed up by the lifter 10 (FIG. 2) to adjust the posture of the tray T during the folding operation of the folding members 15, 16 and 17. It stabilizes. The contact member 31 is composed of a pipe rotatably supported by the tip ends of the pair of swing arms 32. The swing arm 32
Is swingably attached to a box-shaped support bracket 33, as shown in FIG.

Next, the sealing device 20 shown in FIG. 7 will be described. In FIG. 7, the sealing device 20 heats and welds the folded portions Fa of the resin film F made of a thermoplastic resin or the like during the transfer of the package A. The sealing device 20 includes, for example, a far infrared heater 22 fixed to a frame (not shown) of the packaging device via a bearing insulator 21, and a frame (not shown) of the packaging device via the bearing insulator 21. The heating roller 23 is rotatably supported. Far infrared heater 22
Are provided so as to penetrate in the axial direction of the heating roller 23. The far-infrared heater 22 is provided with a coating 22c for emitting infrared rays of a specific wavelength on the outer peripheral surface of the metal pipe 22b heated by the heating coil 22a, and heats the heating roller 23 from the inner surface thereof. The heating roller 23
Has a Teflon coating 23b on the outer peripheral surface of an aluminum rotating roller 23a. In addition, 25 is an insulating member.
Further, the lower half of the heating roller 23 is covered with a reflection plate 24 having a U-shaped cross section as shown in FIG.

Next, the seal auxiliary device 40, which is the main part of the present invention, will be described. In FIG. 8, the seal auxiliary device 40 has a pair of pressing rollers 41 which are symmetrical to each other. The pressing roller 41 has a sponge roller 41b mounted on the outer periphery of a pressing roller shaft 41a, and presses the bottom surface Tb side of the tray T against the heating roller 23 of the sealing device 20 to enhance the reliability of heat sealing. Is. As described below, the pressing roller 41 is provided so as to be swingable around a horizontal axis C set on both sides of the transfer path of the package A, and is rotationally driven in the circumferential direction of the roller. To be done.

The seal assisting device 40 includes a drive motor 4
2a rotation causes sprocket 42b and chain 42c
Drive shafts 43 that are rotationally driven in opposite directions via the. As shown in FIGS. 4 and 5, the drive shaft 43 is rotatably supported by a bracket 44 fixed to the main body of the packaging device, and a pressing roller support fitting 46 is provided.
Is rotatably supported. A drive gear 45 is fixed to the drive shaft 43.

The pressure roller support fitting 46 supports the pressure roller shaft 41a of the pressure roller 41, as shown in FIG. Therefore, the pressing roller 41, along with the pressing roller support fitting 46, is moved around the horizontal axis C by the arrow D.
It is swingably supported as indicated by.

On the other hand, a driven gear 47 meshing with the drive gear 45 is fixed to the pressing roller shaft 41a. Therefore, the pressure roller shaft 41a of the pressure roller 41 is
Is driven to rotate in the circumferential direction of the roller via a pair of gears 45, 47 and the like by the rotation of the drive motor 42a (FIG. 8). The pair of gears 45 and 47 are provided on the pressing roller 41.
In order not to hinder the swinging of the, both are composed of helical gears. The pressing roller 41 and the pusher 13 shown in FIG. 2 constitute the transfer device 70 of the present invention.

The pressing roller support fitting 46 of FIG. 4 and the swing arm 32 of the abutting member 31 are connected by a connecting fitting 48 and swing together. Therefore,
The contact member 31 and the pressing roller 41 are lowered downward by their own weight as shown by the chain double-dashed line in FIG.
As the tray T is pushed up to the lap station S, the tray T is rotated to be lifted. Incidentally, as shown in FIG. 5, the rotation center C1 of the swing arm 32 and the horizontal axis C are arranged on a straight line.

Next, the operation of wrapping the product M and the tray T pushed up by the wrap station S of FIG. 3 will be described. As shown by the solid line in FIG. 2, the film F is held by the film feeder 6 in the lap station S in advance. Therefore, when the tray T is pushed up by the lifter 10, as shown in FIG. 3, the film F is in close contact with the upper surface and the upper end of the product M and the tray T. At this time, product M
On the upper surface of the pair of contact members 31 through the film F.
Abut. On the other hand, due to the rise of the product M, the contact member 31
Rotates around the horizontal axis C (FIG. 4) together with the swing arm 32 and is pushed up.

In this state, the pair of left and right folding plates 15, 15
However, when moving in the left-right direction L, R along the bottom surface of the tray T, the left and right side edge portions Fl, Fr of the film F are folded into the bottom surface side of the tray T. After this, the rear folding plate 16 is forward F
After moving to o, the rear side edge Fb of the film F is folded into the bottom surface of the tray T. A little later than the forward movement of the rear folding plate 16, the pusher 13 moves to the front Fo and pushes out the tray T to the front Fo. Along with this extrusion, the film F is folded by the front folding member 17 on the bottom surface side of the front portion of the tray T. During the folding operation by the rear folding plate 16 and the front folding member 17, since only the front end of the film F in FIG. 2 is gripped by the film feeder 6, the tray T is moved to the tray T as the pusher 13 advances.
There is a slight rotational force that makes the product fall forward, but the product M
Since the contact member 31 is in contact with the upper surface of the tray, the tray T smoothly moves to the front free roller 18 of the front Fo as shown in FIG.
Go up.

Here, as shown in FIG. 4, since the pressing roller support fitting 46 and the swing arm 32 of the abutting member 31 are connected by the connecting fitting 48, the abutting member 31 is lifted by the rise of the product M. When pushed up, the pushing roller 41 also rotates around the horizontal axis C (FIG. 5) and is lifted upward. Therefore, when the tray is moved later, it is possible to prevent the tray from coming into contact with the side surface of the pressing roller 41. Therefore, even with the pressing roller 41 having a small diameter, as shown in FIG. Can be transferred.

With the forward movement of the pusher 13, the drive motor 42a (FIG. 8) is driven, and the pressing roller 41 rotates along the conveying direction of the package A. As a result, the package A on the free roller 18 passes over the heating roller 23. At this time, since the pressing roller 41 loads the weight of the pressing roller 41 and the contact member 31 onto the package A, the bottom surface Tb of the package A is pressed against the heating roller 23 to promote heat sealing of the film F.

In the above structure, as shown in FIG. 8, since the pressing roller 41 is swingably supported about the horizontal axis C, the pressing roller 41 is supported by the two-dot chain line in FIG. The range of vertical movement can be increased. Therefore, the package A can be pushed out to the front Fo (FIG. 2) while pressing the package A having a high height from the package A having a low height from above to promote heat sealing.

Further, since a pair of pressing rollers 41 are provided on the left and right, even a packaged product A having a rigid bridge Mb in the center as shown in FIG. Since the left and right parts that are apart from each other can be pressed, the transportation state is easily stabilized. Therefore, a good sealed state can be obtained.

By the way, in the above-mentioned prior art, FIG.
A pressing roller 41A extending horizontally as shown in FIG.
However, since the upper surface of the packaged product A is always pressed, the product M in the packaged product A may be crushed or the film F may adhere to the upper surface of the product M to make the product M look unattractive. On the other hand, in this embodiment, by setting the positional relationship between the pressing roller 41 and the heating roller 23 in FIG. 10 as described below, heat sealing can be performed without impairing the appearance of the product M. .

That is, as shown in FIG. 10 (b), since the pressing roller 41 is inclined, it may come into contact with the corner Tc of the tray T. In this case, the pressing roller 41 is a product M.
Since it does not come into strong contact with the upper surface of the product M, the risk of crushing the product M is reduced. Therefore, heat sealing can be performed without impairing the appearance of the product M.

In the case of a heavy product M, the contact pressure necessary for heat sealing can be obtained by the weight of the product M without pressing the package A downwardly by the pressing roller 41. However, in the conventional example of FIG. 12A, a constant large pressing force is applied regardless of the weight of the product M,
The appearance of the product M may be impaired.

On the other hand, in this embodiment, as described below, the heavier the weight of the product M, the smaller the pressing force of the pressing roller 41 can be. The reason will be described below. In FIG. 10B, when the swing angle formed by the horizontal line H and the lower surface of the pressing roller 41 is θ, the horizontal axis C
From the balance of the moment around the
The reaction force Wa of the pressing force applied to the package A by the
It is represented by a formula. Wa · La = W · L · cos θ (1) where W: downward rotational force due to the weight of the pressure roller, etc. L · cos θ: moment arm from the center of rotational force W to the horizontal axis C La: Moment arm from the contact portion of the pressing roller to the horizontal axis C In the above formula (1), if L is constant and La is substantially constant, the reaction force Wa decreases as the swing angle θ increases. On the other hand, in general, the product M tends to be heavier as it is taller and the tray T is larger. Therefore, the heavier the product M, the larger the swing angle θ,
Therefore, the reaction force Wa becomes smaller. Therefore, the heavier the product M, the smaller the pressing force, and as a result, the risk of impairing the appearance of the product M is reduced.

For the purpose of adjusting the pressing force of the pressing roller 41, a spring is provided in the direction in which the pressing roller 41 is lifted up, or the pressing roller 41 in the support metal fitting 46.
A weight may be provided on the opposite side.

By the way, the conventional heating roller 51 shown in FIG. 12A is heated from the outside by the lower heater 52, so that the portion close to the heater 52 becomes hot but the upper portion rises. It is difficult to heat. For example, after passing the package A, the surface temperature of the upper portion of the heating roller 51 is unlikely to rise, and when the wind blows the heating roller 51.
The temperature of the upper surface at is decreased. Therefore, the reliability of heat sealing is not improved yet.

On the other hand, in this embodiment, as shown in FIG. 7, in the axial direction of the heating roller 23 rotatably supported,
Since the heater 22 is provided so as to penetrate therethrough, the heater 22 uniformly heats the heating roller 23 from the inside.
The temperature of the outer peripheral surface of 3 is likely to be uniform. Therefore, even if the heating roller 23 rotates, the heating roller 23 can be sealed at a constant temperature, and the reliability of heat sealing is improved.

Although the pressing roller 41 is driven by the drive motor 42a (FIG. 8) in the above embodiment, the pressing roller 41 does not necessarily have to be driven in the present invention. For example, if the pusher 13 shown in FIG. 2 allows the package A to be carried out onto the direction change conveyor 3, it is not necessary to drive the pressing roller 41.

In the above embodiment, the pair of gears 45 and 47 in FIG. 5 are helical gears.
The pressing rollers 41 (FIG. 4) may be swingably supported and driven to rotate by forming bevel gears 5 and 47. Further, a round belt or the like may be used to support the pressing roller 41 in a swingable manner and to rotate the pressing roller 41.

In the above embodiment, the package A was transported horizontally as shown in FIG. 9. However, the package A need only be transported on a plane that is nearly horizontal, and may be transported on a slightly inclined plane. May be. Further, the sealing device 20 may be the conventional sealing device 50 as shown in FIG.

[0039]

As described above, according to the present invention, the pressing rollers for pressing the bottom surface side of the tray wrapped with the stretch film against the sealing device are set on both sides of the package transfer path. Since it is swingable around, it can be displaced up and down greatly by swinging the pressure roller, which widens the range of heights of products that can be pressed. Can be heat sealed. Further, since the pair of pressing rollers are provided on the right and left sides, the conveyed state of the packaged product is stable, so that a good sealed state can be obtained.

[Brief description of drawings]

FIG. 1 (a) is a side view of a packaging weighing and pricing device according to an embodiment of the present invention, and FIG.

FIG. 2 is a vertical cross-sectional view of the packaging device.

FIG. 3 is a perspective view of a lap station.

FIG. 4 is a perspective view of a seal auxiliary device and the like showing a main part of the present invention.

FIG. 5 is a vertical sectional view of the same.

FIG. 6 is a transverse sectional view of the same.

FIG. 7 is a vertical sectional view of a sealing device.

FIG. 8 is a front view showing a pressing device and the like.

FIG. 9 is a vertical cross-sectional view of the packaging device showing the operation of heat sealing.

FIG. 10 is a front view showing the operation of the pressing roller.

FIG. 11 is a bottom view showing a general arrangement of folding plates.

FIG. 12 is a side view and a front view showing a conventional example.

[Explanation of symbols]

20 ... Sealing device, 40 ... Sealing auxiliary device, 41 ... Pressing roller, 70 ... Transfer device, A ... Packaged product, C ... Horizontal axis,
F ... Film, Fa ... Folding part, T ... Tray.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiyuki Sakata One share at 959 Shimoda, Ritto-cho, Kurita-gun, Shiga Prefecture Inside the Shiga factory, Ishida Hoki Co., Ltd. No.1 stock company Ishida Hoki Co., Ltd. Shiga factory

Claims (1)

[Claims] 1. A transfer device for horizontally transferring a packaged product in which a resin film covering an upper part of a tray is folded on the bottom side of the tray, and a transfer device for transferring the packaged product between the folded parts of the folded resin film. A sealing device that heats the inside of the package and welds them together, and a pressing roller that is rotatably provided along the transfer direction of the package and presses the package from above to seal the bottom surface side of the tray against the sealing device. A packaging device comprising a device, wherein the pressing roller is supported so as to be swingable around a horizontal axis set on both sides of a package transfer path,
A pair of packaging devices provided symmetrically to each other.