JP3936248B2 - Stretch wrapping machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a stretch wrapping machine that heat seals and wraps a film folded on the bottom of a product.
[0002]
BACKGROUND OF THE INVENTION
Prior to this application, the applicant of the present application filed a patent application regarding this type of stretch wrapping machine (Japanese Patent Application No. 2002-56947). In this patent application, the product is pushed up from below the film stretched horizontally at the packaging station, the upper surface of the product is covered with the film, and the film is folded from the left and right on the lower surface of the product by a pair of left and right folding plates. The rear folding plate disposed below the left and right folding plates further folds the film folded from the left and right while moving the product forward and heat seals the film to wrap the product. The present invention relates to a packaging machine invention.
As shown in FIG. 12A, the tray T is pushed up from below the film F stretched on the packaging station S, and the upper surface of the tray T is covered with the film F. Next, the film F is folded from the left and right on the lower surface of the tray T by a pair of left and right folding plates 64A and 65A. After the operation of the left and right folding plates 64A and 65A is completed, as shown in FIG. 12B, when the rear folding plate 71 moves forward and further folds the film F, the tray T moves forward. When the rear folding plate 71 comes into contact with the front fixing member 72, the heater 72a of the front fixing member 72 melts the film F, the films F are welded between the two 71 and 72, and the tray T is packaged.
[0003]
[Problems to be solved by the invention]
However, in the stretch wrapping machine described in the patent application, after the operation of the left and right folding plates 64A and 65A is completed, the operation of the rear folding plate 71 is performed while the tray T is supported by the left and right folding plates 64A and 65A. Since it is started, wrinkles are likely to occur on the folding line L inside the corner portion Tc of the tray T. Therefore, the appearance of the product is deteriorated.
[0004]
Accordingly, an object of the present invention is to make it difficult for wrinkles to occur on a folding line in a stretch wrapping machine that wraps a product pushed upward with a film while moving forward.
[0005]
[Means for Solving the Problems]
To achieve the above object, the stretch wrapping machine of the present invention pushes up a product from below a film stretched horizontally in a packaging station, covers the top surface of the product with a film, and folds the film into a pair of left and right left and right folds. After folding the product from the left and right on the lower surface of the product, the rear folding plate arranged below the left and right folding plate further folds the film folded from the left and right while moving the product forward In the stretch wrapping machine for heat-sealing a film to wrap a product, the inner sides of the rear part of the left and right folding plates are formed so as to be separated from each other toward the rear.
[0006]
In the present invention, after the left and right folding plates are folded, the rear folding plate advances and the film is folded below the tray. At this time, the tray moves forward. On the other hand, since the inner sides of the rear part of the left and right folding plates are formed so as to approach each other as they go forward, the film is tensioned not only in the front-rear direction but also in the left-right direction as the tray moves forward. work. Therefore, since the film extends along the folding line, wrinkles are hardly generated on the line.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a stretch wrapping machine according to an embodiment of the present invention will be described with reference to the drawings.
This stretch wrapping machine is a small weighing and wrapping device designed to wrap fruits and vegetables with note trays and foods (products) such as fruits and vegetables contained in soft trays. Even products placed on foam trays can be packaged.
In addition, this embodiment demonstrates the case where the goods mounted on the tray are packaged with the tray. The stretch wrapping machine has a weighing function and a label making function, and the wrapping function will be mainly described.
[0008]
overall structure:
As shown in FIG. 1, the stretch wrapping machine has each mechanism attached to the main body frame 2, and mainly includes a product carry-in device 10 and a lift means 30.
[0009]
When the product is placed on the product carry-in device 10 by the operator's hand, the product is weighed by a measuring device (not shown) and then sent to the lift means 30. On the other hand, the film F conveyed above the lift means 30 in FIG. 6 is pre-stretched by a film holding mechanism to be described later by the film supply device 40 shown in the side sectional view of FIG. 2 and the front sectional view of FIG. . When the product (packaged object) M supported by the lift means 30 is pushed up with respect to the pre-stretched film F, the product M is covered with the film F in the state in which the film F is pushed up. It will be in a state (refer to Drawing 6 (c)).
[0010]
As will be described later, first, the left and right film F is folded into the bottom side of the product M by the left and right folding plates 64 and 65, as will be described later. 6 (d) and (e)). In the folding operation, the left and right folding plates 64 and 65 enter the vicinity of the left and right ends of the bottom of the product M and support the bottom of the product M.
Thereafter, the film F on the front and rear sides is folded to the bottom side of the product M by the rear folding plate 71 in FIG. 7 (see FIGS. 7B and 7C). The film F folded on the bottom side of the product M is sandwiched between the rear folding plate 71 and the front fixing member 72 and pressed against the heater 72a provided on the front fixing member 72 to weld the films F together. (See FIG. 7 (d)). Thereafter, the product M is conveyed downstream and is conveyed on the heat sealing means 73, whereby the films F folded on the bottom surface side are collected and welded together.
[0011]
The product M, which has been wrapped with the film F including the heat seal, is taken out by an operator's hand, and a label discharged from a pricing mechanism (not shown) is attached.
[0012]
Film holding mechanism:
The film holding mechanism includes the rear clamp 53 and the front clamp 54 of FIG. 2, and the left and right clamps 51 and 52 and the left and right pushing members 61 and 62 of FIG.
Each of the clamps 51 to 54 can grip the end of the film F by, for example, turning on and off a solenoid switch, and is set to be horizontally movable by a moving mechanism (not shown) as will be described later.
[0013]
The front clamp 54 of FIG. 2 moves backward to grip the leading edge of the film F, and the film F is moved by moving the front clamp 54 forward and the rear clamp 53 backward while holding the film F. The film is unrolled from the film roll R and conveyed above the lift means 30. Thereafter, the film F is gripped by the rear clamp 53 and then cut.
On the other hand, as shown in FIG. 3, left and right pushing members 61 and 62 are provided below the left and right folding plates 64 and 65. Left and right clamps 51 and 52 are provided below the left and right pushing members 61 and 62. The left and right ends of the film F are sandwiched and gripped between the left and right clamps 51 and 52 and the left and right pushing members 61 and 62.
[0014]
The film holding mechanism plays a role of gripping the peripheral edge of the film F when the product M is pushed upward by the lift means 30 and stretches the film F immediately before the film F is pushed up. Perform the pre-stretch operation to set the state. By this pre-stretching operation, the clamps 51 to 54 and the left and right pushing members 61 and 62 holding the peripheral portion of the film F move horizontally in a direction away from each other, and the film F is stretched by a predetermined amount.
[0015]
Lift means 30:
As shown in FIGS. 3 and 7, the lift means 30 includes left and right support members 34 a that support the left and right sides of the bottom surface of the product M. The support member 34a is movable in the vertical direction, and lifts the product M and transfers it to the packaging station S.
[0016]
Film folding mechanism:
The left and right folding plates 64 and 65 shown in FIG. 6 are arranged above the left and right pushing members 61 and 62 and fold the film F on the left and right sides. As shown in FIG. 5, the pushing members 61 and 62 and the folding plates 64 and 65 are notched in a tapered shape so that the inner sides of the rear part are separated from each other toward the rear. On the other hand, the inner sides of the front portions of the pushing members 61 and 62 and the folding plates 64 and 65 are formed substantially parallel to each other. That is, as shown in FIG. 5 or FIG. 9, the two folding plates 64 and 65 approach each other so that a substantially Y-shaped space is formed between the left and right folding plates 64 and 65 that have performed the folding operation. .
In addition, in front of the folding plates 64 and 65, concave portions 64a and 65a cut out in a “U” shape are formed.
[0017]
As shown in FIG. 2, the rear folding plate 71 is disposed below the left and right folding plates 64 and 65 and above the left and right pushing members 61 and 62. The rear folding plate 71 folds the film F from the rear to the bottom side of the product M.
On the other hand, the front side fixing member 72 is fixed to the main body frame 2, and a heater 72a is provided at the center of the rear end of the front side fixing member 72 as shown in FIG. The rear folding plate 71 folds the film F from the rear side to the bottom side of the product M, and sandwiches the film F with the front fixing member 72 to give the film F a pressing force necessary for heat sealing.
[0018]
Control configuration:
As shown in FIG. 4, the stretch wrapping machine includes a microcomputer 3 for controlling the above-described devices. The microcomputer 3 is connected to a stroke key unit 11, a label printer 12, a touch screen 13, a control device with weighing value 14 and a local control device 15 through an interface (not shown).
Each device described above is connected to the local control device 15, and each device is controlled by the microcomputer 3.
[0019]
The microcomputer 3 includes a CPU 4 and a memory 7. The memory 7 is provided with a tray information storage unit 7a. As shown in FIG. 4B, the tray information storage unit 7a associates tray information including the width W1 and depth D1 of the upper surface of the tray and the width W2 of the bottom surface of the tray for each tray number. Is remembered. The tray widths W1 and W2 and the depth D1 are preliminarily input from the touch screen 13 and the stroke key unit 11 and registered.
[0020]
The CPU 4 calculates a stroke to a predetermined entry end into which the pair of left and right folding plates 64 and 65 shown in FIG. 8B enter according to the width W2 of the bottom surface of the tray T. That is, based on the width W2 of the bottom surface of the tray T, the CPU 4 calculates a movement stroke from the left and right ends of the bottom of the tray T to a position Px that has advanced inward by a predetermined distance α, and the left and right folding plates 64, Move 65 to the entry end. Thus, the left and right folded plates 64 and 65 are at a fixed position from the left and right ends of the bottom of the tray T regardless of the width W2 of the bottom surface of the tray T at the entry ends.
Thus, by setting the position Px of the entry end, as shown in FIG. 9A, at the entry end, the sides 64L, 65L inside the rear portions of the left and right folding plates 64, 65 and , The rear side TL of the bottom of the tray T intersects at a point O.
[0021]
Packaging operation:
Next, among the wrapping operations of the stretch wrapping machine, the folding operation and the heat sealing operation of the film F will be mainly described.
When the operator performs a predetermined operation and inputs a tray number, the CPU 4 reads the tray information corresponding to the tray number from the tray information storage unit 7a. When the operator places the product M on the touch screen 13 shown in FIG. 1, the packaging operation starts.
[0022]
As shown in FIG. 6 (a), when the film F is conveyed above the lift means 30 by the film supply device 40 (FIG. 2), the left and right pushing members 61 and 62 and the left and right clamps 51 and 52 cause the film to move. The left and right ends of F are gripped. On the other hand, the front and rear ends of the film F are gripped by the front and rear side clamps 53 and 54.
[0023]
As shown in FIG. 6B, after gripping the film F, the left and right pushing members 61 and 62 and the left and right clamps 51 and 52 and the front and rear side clamps 53 and 54 (FIG. 2) move in the horizontal direction away from each other. The film F is prestretched.
Thereafter, as shown in FIGS. 6C and 8A, the product M is pushed up by the lift means 30 with respect to the pre-stretched film F, and the upper surface and side surfaces of the product M are covered by the film F. It becomes a broken state. The front and rear clamps 53 and 54 are moved inward by the pushed up product, and the tension when the product M hits the film is relaxed.
[0024]
Left and right folding operation;
As shown in FIG. 6 (d), after the push-up, the left and right folding plates 64 and 65 move inward from each other. On the other hand, the left and right pushing members 61 and 62 move inward following the left and right folding plates 64 and 65 so that excessive tension does not act on the film F, and lower the left and right clamps 51 and 52 at appropriate positions. The release of the left and right portions of the film F is released.
[0025]
Here, the CPU 4 performs a predetermined calculation based on the width W2 of the bottom of the tray read from the tray information storage unit 7a in FIG. 4B, and the stroke to the entry ends of the left and right folding plates 64, 65. Is calculated. As shown in FIG. 8B, the left and right folding plates 64 and 65 are controlled by the CPU 4 and moved by the calculated stroke.
On the other hand, as shown in FIG. 6E, the left and right pushing members 61 and 62 continue to move inward further and stop at a predetermined position.
[0026]
Post-folding operation;
After the left and right folding operation, the rear folding plate 71 shown in FIG. 7A starts moving forward, and the rear clamp 53 moves forward with a slight delay so that excessive tension does not act on the film F. To do. On the other hand, the left and right support members 34 a are lowered, and the product M is supported by the left and right folding plates 64 and 65.
Thereafter, as shown in FIG. 7B, when the rear clamp 53 is advanced while the rear folding plate 71 is advanced, the product M is slid forward on the left and right folding plates 64 and 65. At this time, by moving the front clamp 54 backward, the tension of the film F can be adjusted, and thereby the product can be smoothly slid.
[0027]
In the packaging operation, since the sides 64L and 65L inside the left and right folded plates 64 and 65 shown in FIG. 8B are tapered, the intersection P between the rear folded plate 71 and the left and right folded plates 64 and 65 is formed. Since the position does not penetrate deeply into the corner Tc of the tray T, the left and right folding amounts of the film F with respect to the corner Tc of the tray T become shallow.
[0028]
Further, after the folding of the left and right folding plates 64 and 65, the rear folding plate 71 of FIG. 9A advances to fold the film F below the tray T. At this time, as shown in FIGS. 9A and 9B. Thus, the tray T moves forward. On the other hand, since the sides 64L and 65L on the inner side of the rear part of the left and right folding plates 64 and 65 are formed so as to approach each other as they go forward, the film F is not only on the front and rear as the tray T moves forward. There is also tension in the left and right direction.
In this way, the intersection point P does not penetrate deeply into the corner Tc, and the film F is stretched along the folding line L during the wrapping operation because the film F is tensioned not only in the longitudinal direction but also in the lateral direction. It becomes difficult to cause wrinkles on the line L.
[0029]
Thereafter, the rear folding plate 71 continues to move forward, and the product M is slid forward on the left and right folding plates 64 and 65 via the film F as the rear folding plate 71 advances.
[0030]
As shown in FIG.7 (d), the back folding plate 71 will contact | abut to the front side fixing member 72, and the heater 72a welds film F soon.
Here, as shown in FIGS. 9A and 9B, since the concave portions 64a and 65a are formed at the tips of the left and right folding plates 64 and 65, the film F on the lower surface of the tray T is gathered small. It is done.
Thereafter, the product M is discharged onto the heat sealing means 73 (FIG. 1).
[0031]
By the way, a stretch wrapping machine in which a taper is formed on the left and right folded plates is disclosed in Japanese Patent No. 2882331 and Japanese Patent Publication No. 5-49523. These folding methods are shown in FIGS.
[0032]
In the conventional stretch wrapping machine of FIG. 10, the front and rear folding plates 71B and 72B approach each other while the tray T is stopped on the left and right folding plates 64B and 65B. Therefore, even if the film F is folded by the front and rear folding plates 71B and 72B, the tray T does not escape from the front and rear folding plates 71B and 72B. The effect of preventing wrinkles from occurring in the folding line L of the film F cannot be exhibited.
[0033]
On the other hand, in the conventional stretch wrapping machine shown in FIG. 11, the tray T does not move when the front folding plate 72C moves toward the tray T as in the above-described conventional example.
[0034]
By the way, as shown in the longitudinal cross-sectional view of FIG. 5C, a heat resistant cloth 71 f may be wound around the rear folding plate 71. Surface fasteners 71h are attached to both ends of the cloth 71f, and are detachably attached to the rear folding plate 71.
Here, when packaging a product with much moisture, the moisture may leak from the gaps in the film F and adhere to the rear folding plate 71 during packaging. Cleaning the rear folding plate 71 is troublesome because it is necessary to remove the components above the rear folding plate 71. Therefore, by attaching the cloth 71f to the rear folding plate 71, it is possible to prevent moisture from adhering to the rear folding plate 71 and the like. In addition, since the surface fastener 71h is provided at the end of the cloth 71f, the apparatus can be used while being easily removed and cleaned.
[0035]
As described above, the preferred embodiments have been described with reference to the drawings. However, those skilled in the art will readily understand various changes and modifications within the obvious scope by looking at the present specification.
For example, the heater may be provided on the rear folding plate.
The film may be folded as long as the four peripheral edges of the film are folded into the bottom of the product by the operation of the folding member, and the left and right pushing members are not necessarily provided.
Alternatively, the stroke of the left and right folded plate and the width of the tray bottom may be stored in association with each other, the stroke of the left and right folded plate may be read according to the width of the tray bottom, and the left and right folded plates may be operated with the stroke.
Accordingly, such changes and modifications are to be construed as within the scope of the present invention as defined by the claims.
[0036]
【The invention's effect】
As described above, according to the present invention, wrinkles can be prevented from occurring on the folding line of the film folded by the left and right folding plates, and a beautiful packaging finish can be obtained.
[0037]
Further, the position of the entry end into which the left and right folding plates enter is set according to the width of the tray, and the inner side of the rear part of the left and right folding plates at the entry end and the rear side of the tray are set to intersect. Then, the intersection of the rear folding plate and the left and right folding plates proceeds obliquely forward toward the intersection of the rear edge of the tray and the taper line, so that the intersection of the plates proceeds toward the corner of the tray. Then, it can be folded with the corner of the tray as a reference.
[0038]
Note that if the left and right entry ends are set to a substantially constant position from the left and right ends of the bottom of the tray, the film is folded to a certain position with respect to the left and right sides of the tray. The folded state is stable.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment of a stretch wrapping machine of the present invention.
FIG. 2 is a partially broken side view of the stretch wrapping machine.
FIG. 3 is a front sectional view of the stretch wrapping machine.
FIG. 4A is a schematic configuration diagram of a stretch wrapping machine, and FIG. 4B is a chart showing storage contents of a storage unit.
5A and 5B are schematic perspective views showing a packaging operation, and FIG. 5C is a longitudinal sectional view showing a rear folding plate.
FIG. 6 is a process diagram showing a packaging method.
FIG. 7 is a process diagram showing a packaging method.
FIG. 8 is a schematic plan view of a main part showing a packaging method.
FIG. 9 is a schematic plan view of a main part showing a packaging method.
FIG. 10 is a perspective view of a main part showing a conventional stretch wrapping machine.
FIG. 11 is a perspective view of a main part showing another conventional stretch wrapping machine.
FIG. 12 is a perspective view of a main part showing another conventional stretch wrapping machine.
[Explanation of symbols]
S: Packaging station F: Film M: Product 64, 65: Left and right folding plate 71: Rear folding plate 72a: Heater

Claims (6)

The product is pushed up from below the film stretched horizontally in the packaging station, the upper surface of the product is covered with the film, the film is folded from the left and right on the lower surface of the product by a pair of left and right folding plates, and then the left and right folding plates In the stretch wrapping machine which wraps the product by folding the film folded from the left and right further and heat-sealing the film while moving the product forward while the folding plate arranged below is moved forward,
A stretch wrapping machine, characterized in that the inner sides of the rear part of the left and right folding plates are formed so as to be separated from each other as they go rearward. In claim 1,
The stretch packaging machine in which the inner sides of the front part of the left and right folded plates are formed substantially parallel to each other. In claim 1 or 2,
A stretch wrapping machine in which when the rear folding plate moves forward, the film is welded to each other by a heater provided on the rear folding plate and / or the front fixing member while abutting on the front front fixing member. In claim 1, 2 or 3,
When the product is stored in a tray,
The position of the entry end where the pair of left and right folded plates enter the bottom surface side of the tray is set according to the width of the tray, so that the inner side of the rear portion of the left and right folded plates at the entry end and the tray Stretch wrapping machine that is set to intersect with the rear side. In claim 4,
The stretch wrapping machine in which the positions of the left and right entry ends are set at a substantially constant position from the left and right ends of the bottom of the tray. 6. The film according to any one of claims 1 to 5, wherein the rear end side of the film is gripped and the rear folding plate moves forward when folding the film, thereby preventing an excessive tension from acting on the film. Stretch wrapping machine further equipped with a rear clamp.

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