JP2003205907A - Packaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a packaging apparatus in which the arrangement pitch of the support members of a lift mechanism can be reduced to support the bottom of a commodity in a more stable manner. <P>SOLUTION: The packaging apparatus comprises a film mechanism for holding a film tense, a lift mechanism, and a folding mechanism. The lift mechanism has front/rear bases 34 and a plurality of supporting members 36, 34b, which are extended upward from the front/rear bases 34. The supports 36b of the supporting members 36 support the bottom of the commodity. The folding mechanism folds the periphery of a film that is pressed against the commodity by the lift mechanism toward the bottom side of the commodity. The supporting members 36 shrinks vertically when receiving a horizontal force from the folding mechanism. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a packaging device, in particular
The present invention relates to a packaging device that performs a packaging operation of folding a peripheral portion of a film pressed against an article to be packaged into a bottom side of the article to be packaged.

[0002]

2. Description of the Related Art As a device for covering and sealing an object to be packaged such as fruits and vegetables and foods placed on a tray with a film,
So-called stretch packaging devices are widely known. In this stretch wrapping device, the object to be wrapped is pushed up against the film held in tension, the peripheral portion of the film is folded to the bottom side of the object to be heat-sealed, and the object to be wrapped is wrapped with the film.

An example of such a stretch wrapping device is
It is disclosed in JP-A-11-208611. Here, the object to be packaged is pushed up against the film by an elevator (lift mechanism), and the film is folded under the object to be packaged by the folding mechanism. Specifically, during the folding operation of the left and right folding plates, the elevator head (support member) is tilted so that the left and right folding plates enter under the packaged object. Further, when the left and right folding plates enter below the article to be packaged, the elevator is lowered and the rear folding plate is advanced to the lower side of the article to be packaged. In this way, the left and right and rear edges of the film are folded downward, and the packaged object is pushed out by the pusher to the discharge conveyor on the front side. As a result, the front edge of the film that hits the front folding plate is folded under the object to be packaged. The film whose periphery is folded under the article to be packaged in this manner is heat-sealed by the heat generating function of the discharge conveyor.

[0004]

Among the objects to be packaged by the stretch wrapping device as described above,
In addition to the products on the tray, there are also bare products without trays (such as cabbage and eggplant). When packaging such an article to be packaged, from the viewpoint of protecting the article to be packaged, it is desirable to arrange a plurality of support members of the lift mechanism at a fine pitch. Further, even when the tray is made of a soft material, it is desirable that the supporting members that support the tray be arranged at a fine pitch.

However, the lift mechanism of the conventional packaging apparatus has a structure in which the supporting member for supporting the object to be packaged is tilted like the apparatus of the above publication. In such a falling structure, a space is required for the supporting member to fall,
There is a limit in reducing the pitch of the support members arranged in the tilting direction. An object of the present invention is to provide a packaging device capable of reducing the arrangement pitch of the support members of the lift mechanism in order to more stably support the bottom of the packaged object.

[0006]

A packaging apparatus according to a first aspect comprises a film holding mechanism, a lift mechanism, and a folding mechanism. The film holding mechanism holds the film under tension. The lift mechanism has a base member and a plurality of support members extending upward from the base member. The upper part of these support members supports the bottom part of the packaged object. Also,
The lift mechanism presses the packaged object supported by the support member against the film held by the film holding mechanism. The folding mechanism folds the peripheral portion of the film pressed against the article to be packaged by the lift mechanism to the bottom side of the article to be packaged. Then, at least one support member of the lift mechanism contracts in the vertical direction when a horizontal force is applied from the folding mechanism.

Here, the article to be packaged is supported by a plurality of support members extending upward from the base member of the lift mechanism. The packaged object supported by these support members and pressed against the film held by the film holding mechanism is packaged by the folding mechanism folding the peripheral portion of the film to the bottom side of the packaged object. Then, here, when a force including a horizontal component is applied from the folding mechanism to at least one support member (hereinafter, referred to as a predetermined support member) when the film is folded by the folding mechanism, the predetermined support member moves up and down. I try to shrink in the direction. As described above, since the structure in which the predetermined support member is vertically contracted is used instead of the conventional structure in which the predetermined support member is tilted, it is not necessary to secure a space for the predetermined support member to be tilted. Therefore, it is possible to reduce the arrangement pitch of the plurality of support members including the predetermined support member and the other support members. This makes it possible to more stably support the bottom of the product to be packaged, and even if the product to be packaged is a bare product without a tray or a product placed on a soft tray, the product will not be deformed or deformed. Packaging is started with almost no damage.

A packaging apparatus according to a second aspect is the packaging apparatus according to the first aspect, wherein the support member that contracts in the vertical direction has a first member and a second member. A locked portion is formed on the first member. The first member is fixed to the base member. The second member is formed with a locking portion that locks with the locked portion of the first member, and a support surface that is located above the locking portion and that supports the article to be packaged. Then, when a horizontal force acts on the second member from the folding mechanism, the locking of the locked portion with respect to the locked portion is released, and the second member moves downward.

Here, when a force acts on the second member from the folding mechanism, the locking of the locking portion of the second member with respect to the locked portion of the first member is released, and the second member of the predetermined supporting member moves downward. Move to. As a result, the support of the packaged object by the predetermined support member is released, and the packaged object is in a state of being supported by another support member or the like. Then, in this state, the member of the folding mechanism can enter the bottom side of the package.

As described above, since the predetermined support member is vertically contracted by releasing the locking of the second member to the first member by the action of the force from the folding mechanism, the conventional predetermined tilting is performed. Unlike the support member, the surface supporting the article to be packaged hardly moves upward. Therefore, the deformation or damage of the packaged item can be further suppressed.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION <Overall Configuration and Schematic Operation> FIGS. 1 to 3 are a schematic side view, a front view, and a plan view of a stretch wrapping apparatus according to an embodiment of the present invention. A control block of the stretch wrapping device 10 is shown in FIG. This stretch wrapping device 10 is a small-sized weighing and wrapping price device, and is designed for wrapping fruits and vegetables in a notebook tray or wrapping foods (products) such as fruits and vegetables stored in a soft tray. However, packaging is possible even for products placed on ordinary foam trays.

The stretch wrapping device 10 has a weighing function and a pricing function (a label producing function including a weighing value and a price).
However, here, the description will focus on the packaging function of the stretch packaging device 10. The stretch wrapping device 10 is a device in which each mechanism is attached to the main body frame 15, and mainly includes a product introduction mechanism 20, a lift mechanism 30, a film transport mechanism 40, a film holding mechanism 50, and a film left and right pushing mechanism. A mechanism 60, a left-right folding mechanism 66, and a heat-sealing / film front-back folding mechanism 70 are provided.

When the product G (see the product G on the front side in FIG. 1) is placed on the introduction table 21 of the product introduction mechanism 20 by the operator's hand, the product G is weighed by the weighing device 29, and then the product G is measured. G is sent to the lift mechanism 30 (see FIG. 1).
See item G on the back). On the other hand, the film transport mechanism 40
The film F conveyed by the lift mechanism 30 is pre-stretched by the film holding mechanism 50 while holding the front, rear, left, and right ends thereof (FIG. 10B).
reference). The product G supported by the lift head 32 of the lift mechanism 30 on the pre-stretched film F
When is pushed up, the commodity G is in a state in which the film F is pushed up and the upper side and the side are covered with the film F (see FIG. 10C).

The peripheral portion of the film F which covers the upper and lateral sides of the product G in this manner is folded to the bottom side of the product G by the left and right folding plates 64 and 65 and the rear folding plate 71 (see FIG. 10 (e)). ). At the time of this folding operation, the left and right folding plates 64, 65 enter the vicinity of the left and right ends of the bottom of the product G, and play a role of supporting the bottom of the product G together with the lift head 32 of the lift mechanism 30. The film F folded on the bottom side of the product G receives heat input from the nichrome wire 81 attached to the front fixing member 72 while being sandwiched between the rear folding plate 71 and the front fixing member 72. , And heat-sealed (see FIG. 13C).

The product G thus wrapped with the film F including the heat seal is taken out by the operator's hand, and the label discharged from the pricing mechanism (not shown) is attached. <Structure of Product Introduction Mechanism 20> The product introduction mechanism 20 is shown in FIG.
As shown in FIG. 4 and FIG. 4, it mainly includes an introduction table 21, an introduction table vertical movement motor 22, and an introduction table longitudinal movement motor 23. The introduction table 21 supports the product G by a plurality of support plates 21a arranged in the left-right direction. These support plates 21a and the lift mechanism 3 shown in FIGS. 6 and 7.
The support members 34b, 36, 37, 39 (described later) of No. 0 are arranged so as to be displaced in the left-right direction. Below the introduction table 21, a weighing instrument 29 for measuring the weight of the product G placed on the introduction table 21 is arranged. This introduction table 21
Is connected to the introduction table longitudinal movement motor 23 via a belt, a pulley, etc., and moves forward and backward by the operation of the introduction table longitudinal movement motor 23. Further, the entire forward / backward movement unit including the introduction table 21 and the introduction table longitudinal movement motor 23 is configured to move up and down by the introduction table vertical movement motor 22.

When the motors 22 and 23 of the product introduction mechanism 20 are activated by a command from the control unit 90 described later, the introduction table 21 makes a rectangular motion, and the product G placed on the introduction table 21 by the walking beam system is moved. It is sent onto the support members 34b, 36, 37, 39 of the lift mechanism 30 on the rear side. It should be noted that instead of using the two motors of the introduction table vertical movement motor 22 and the introduction table longitudinal movement motor 23, it is possible to combine the roles of these two motors with one motor.

<Structure of Lift Mechanism 30> Lift mechanism 30
Are provided to support the bottom of the product G sent from the product introduction mechanism 20 and lift the product G upward. The lift mechanism 30 also plays a role of supporting the bottom of the product G when the peripheral portion of the film F is folded to the bottom of the product G, as described later.

As shown in FIGS. 1, 2, and 4, the lift mechanism 30 mainly includes vertical rails 30a arranged on the left and right, and a slide base 31 and a slider 31a that move up and down along the vertical rails 30a. , Link mechanism 30
c, a lift motor 30d for moving the slide base 31 up and down via the link mechanism 30c, and a lift head 32 mounted on the front and rear sliders 31b on the slide base 31.

[Slide Base 31 and the Like] The slide base 31 and the slider 31a are integrated by a vertically extending connecting member. The link mechanism 30c rotates around the pin support portion 30b by the operation of the lift motor 30d, and moves the slide base 31 and the slider 31a up and down along the vertical rail 30a.

Further, on the upper surface of the slide base 31, a front and rear slider 31b which is movable back and forth on the slide base 31 is mounted. The front and rear slider 31b is biased rearward by a spring member (not shown). [Lift Head 32] The lift head 32 is an assembly mounted on the upper surface of the front and rear slider 31b, and as shown in FIGS.
The front / rear base 34 includes a left / right center support member 36 and a center support member 37 fixed to the center base 33, and a center front / rear support member 34b and a left / right front support member 39 fixed to the front / rear base 34. .

The central base 33 has a front and rear slider 31b.
A fixed plate 33a fixed to the vertical plate 33a, a vertical plate 33b extending upward from the center portion of the fixed plate 33a in the left-right direction, and an upper part protruding left and right, and link holding plates 33c fixed to the left and right ends of the vertical plate 33b. It is configured. Central base 33
The front and rear bases 34 arranged in front of and in the rear are divided into front and rear parts, respectively, and are supported by the link holding plate 33c via the parallel link members 34a. Therefore,
The front-rear base 34 is movable in the front-rear direction with respect to the central base 33. Normally, the front-rear base 34 is supported by the link holding plate 33c by a spring member and a stopper (not shown) so as to be in the state shown in FIG. That is, the front-rear base 34 can be moved only from the state shown in FIG. 5 to the central base 33 side. Specifically, FIG.
The state changes from the state shown by the dotted line in 5 (b) to the state shown by the solid line.

As shown in FIGS. 6 and 7, three left and right central support members 36 are arranged on the left and right, respectively, and each is supported by a support base 35 extending upward from the vertical plate 33b of the central base 33. Has been done. The left right center support member 36 includes a support portion 36b that supports the bottom of the product G,
The frame 36a is fixed to the lower surface of the support portion 36b, and the pins 36c for supporting the lower portions of both ends of the frame 36a by the support base 35 by pins. As shown in FIG. 16, these left and right center support members 36 receive a force when left and right folding plates 64, 65 and left and right pushing members 61, 62, which will be described later, come in, and rotate about the pin 36c. It moves and falls inward. However, normally, a frame member 36 is used so that the state shown in FIG.
a is energized.

The center support member 37 is a pair of members provided between the left and right center support members 36 on the left and right sides as shown in FIG. These central support members 37 are composed of a fixed portion 37a fixed to the vertical plate 33b of the central base 33, and a support portion 37b mounted on the fixed portion 37a. The support portion 37b that supports the bottom of the product G and the fixed portion 37a are integrated, and the support portion 37b of the central support member 37 is not structured to fall.

As shown in FIGS. 5 and 15, the center support member 37 and the left and right side center support members 36 form a concave shape in a side view together with the center front and rear support member 34b and the left and right side front and rear support members 39. There is. Therefore, the product G is stably supported. As shown in FIGS. 6 and 7, three left and right front and rear support members 39 are arranged on each of the front and rear bases 34, respectively. The twelve left and right side front and rear supporting members 39 are a fixing member (first member) 38 extending upward from the upper surface of the front and rear base 34, and a supporting portion (second member) supported by the fixing member 38 and on which the product G is placed. ) 39b. As shown in FIG. 6, the fixing member 38 is fixed to the upper surface of the front-rear base 34, and has a pair of vertical grooves 38a from the central portion to the lower portion and a locked portion 38b at the upper end. A frame 39a including two pin support portions extending downward from the support portion 39b is integrally fixed to the lower surface of the support portion 39b. The pin support portion of the frame 39a supports two upper and lower pins 39c and 39d, as shown in FIGS.
The upper pin (locking portion) 39c locks the locked portion 38b of the fixing member 38 from above. The lower pin 39d is arranged so as to move along the vertical groove 38a of the fixing member 38 (see FIGS. 6 and 16). Further, the upper surface of the support portion 39b has a slight angle with respect to the horizontal plane and serves as a support surface for supporting the bottom portion of the product G.

The left and right front and rear support members 39 having such a structure
As shown in FIGS. 15 (a) and 16,
When a force along the horizontal direction is applied to 9b from the outside, it contracts up and down. Specifically, when a force is applied to the support portion 39b from the outside, the pin 39c that has been engaged with the engaged portion 38b of the fixing member 38 from above is displaced to the inside, and the support portion 39b.
b and the frame 39a fall. By this fall,
The support portion 39b and the fixing member 38 mainly move relative to each other in the vertical direction, and the left and right front-back supporting member 39 contracts in the vertical direction. From another point of view, the support surface of the left and right front and rear support members 39 supporting the product G is lowered by the fall of the support portion 39b. The support portion 39b and the frame 3
When 9a falls, the lower pin 39d moves along the vertical groove 38a. Further, since the pin 39c is biased toward the front-rear base 34 side (downward) by the spring 39e, the support portion 3
The dropping operation of 9b and the frame 39a is performed quickly.

In addition, the state in which the support portion 39b has dropped (see FIG. 1)
6) automatically returns to its original position when the entire lift head 32 descends along the vertical rail 30a. When the lift head 32 descends, a return member (not shown) enters into the lift head 32 through a gap between the front and rear bases 34 that are divided into two, and lifts the frame 39a relatively,
The upper pin 39c is returned to the locked portion 38b of the fixing member 38. Therefore, the lowered lift head 32 is always in a state in which the pin 39c as shown in FIG. 6 is placed on the locked portion 38b.

As shown in FIG. 6, the central front-rear support member 34b is a member fixed to the center portion of each front-rear base 34 in the left-right direction, and extends upward from the front-rear base 34. The central front-rear support member 34b includes a fixed portion 34d fixed to the front-rear base 34 and a support portion 34c mounted on the upper portion of the fixed portion 34d.
The support portion 34c that supports the bottom portion of the product G and the fixing portion 34d are integrated, and the central front-rear support member 34b does not contract vertically unlike the left-right front-rear support member 39.

<Structure of Film Conveying Mechanism 40> The film conveying mechanism 40 conveys the film F cut into a predetermined size above the product G supported by the lift mechanism 30 and causes the film holding mechanism 50 to hold the film in tension. It is a mechanism. The film transport mechanism 40 mainly moves the roll holding unit 41 that rotatably supports the film roll R, the front clamp 54 that holds the leading end of the film F fed from the film roll R, and the front clamp 54 back and forth. It is composed of a front clamp moving mechanism.
The front clamp moving mechanism is the front clamp longitudinal movement motor 5
6a (see FIG. 4), a belt mechanism, a front clamp support member, and the like. Here, the front clamp 54 is moved back and forth by operating the front clamp forward / backward movement motor 56a. The front clamp 54 grips or separates the front end portion of the film F by turning on / off the front clamp solenoid switch 56b shown in FIG.

When the control section 90 issues a command to convey the film F, the front clamp 54 moves rearward,
The leading end of the film F that has been fed from the film roll R and has reached the vicinity of the rear clamp 53 is grasped. Then, the front side clamp 54 moves forward while holding the leading edge of the film F, so that the film F is lifted by the lift mechanism 30.
Will be located above.

<Structure of Film Holding Mechanism 50> The film holding mechanism 50 mainly includes a front clamp 54 and a front clamp moving mechanism, which are also components of the film transport mechanism 40, a rear clamp 53 and a rear clamp moving mechanism. It is composed of a left clamp 51, a right clamp 52, and a left-right pushing member moving mechanism which is also a component of a film left-right pushing mechanism 60 described later.

The rear clamp 53 is for holding or separating the rear end portion of the film F by turning on / off the rear clamp solenoid switch 55b shown in FIG. Moving. The rear clamp moving mechanism is the rear clamp longitudinal movement motor 55.
a (see FIG. 4), a belt mechanism, a rear clamp support member, and the like.

The left clamp 51 and the right clamp 52 are
As shown in FIG. 9, the film F is provided below the left and right pushing members 61 and 62, which will be described later, and the film F is pushed by the left and right pushing members 6.
The film F is gripped by being sandwiched between the films F and 62. That is, the left clamp 51 and the right clamp 52
Moves up and contacts the left and right pressing members 61 and 62 to grip the film F, and moves down to separate from the left and right pressing members 61 and 62 to release the grip of the film F. Therefore, in order to move the left clamp 51 and the right clamp 52 up and down, as shown in FIG.
A left clamp vertical movement motor 51a and a right clamp vertical movement motor 52a are provided. When the left clamp vertical movement motor 51a and the right clamp vertical movement motor 52a 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.

Further, the left clamp 51 and the right clamp 5
2 is 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, by moving left and right, the left clamp 5
1 and the right clamp 52 do not draw an arc-shaped trajectory,
The left clamp 51 and the right clamp 52 are configured to be able to move slightly up and down with respect to the left clamp support base 51b and the right clamp support base 52b. Therefore, when the left and right pushing members 61, 62 move left and right while the left clamp 51 and the right clamp 52 are pressed against the left and right pushing members 61, 62 from below, the left clamp 51 and the right clamp 52 follow the movement. . That is, the left and right pushing member moving mechanism that moves the left and right pushing members 61 and 62 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 gripping the peripheral portion of the film F when the product G is pushed up by the lift mechanism 30, and the film F is held just before the product G is pushed up. Perform a pre-stretching action to put the tension. By this pre-stretching operation, the respective clamps 53, 54, 51, 52 holding the peripheral portion of the film F horizontally move outward and the film F is stretched by a predetermined amount.

<Structure of Film Left / Right Pushing Mechanism 60> The film left / right pushing mechanism 60 includes left and right pushing members 61, 62.
And a left and right pushing member moving mechanism that moves the pushing members 61 and 62 to the left and right. The left and right pushing member moving mechanism is a film pushing motor 63 shown in FIG.
a, a belt mechanism, a support member that supports the left and right pushing members 61 and 62, and the like. The film pushing motor 63a operates according to a command from the control unit 90 to move the left and right pushing members 61 and 62 to the left and right.

Further, the left and right pushing members 61 and 62 can hold the film F by sandwiching the film F between the left clamp 51 and the right clamp 52, and act as a part of the clamp. Left and right pushing member 6
1, 62 are formed with elongated holes for strengthening the clamping action. Since the same applies to any of the pushing members 61 and 62, the elongated hole 61a formed in the left pushing member 61 shown in FIG. 9B will be described here. The long hole 61a is formed to be long in the front-rear direction, and has a size into which the protruding portion 51c protruding upward from the upper surface of the left clamp 51 can be inserted. When the left clamp 51 moves upward and comes into close contact with the pushing member 61, the protrusion 51c of the left clamp 51 enters the elongated hole 61a, and the film F enters between the protrusion 51c and the elongated hole 61a.
The lateral movement of the film F is strongly restricted. Thus, due to the presence of the protrusion 51c and the long hole 61a,
The grip degree for gripping the film F is enhanced by the clamp 51 and the pushing member 61.

<Structure of Left and Right Folding Mechanism 66> The left and right folding mechanism 66 mainly includes left and right folding plates 64 and 65 and a left and right folding motor 68a (for moving the left and right folding plates 64 and 65 to the left and right). (See FIG. 4). The left and right folding motors 68a are used for the belt mechanism and the folding plate 6.
The folding plate 6 is provided via a supporting member for supporting the 4, 65.
Move 4, 65 left and right.

The left and right folding plates 64 and 65 are arranged above the left and right pushing members 61 and 62, and the rear folding plate 71 will be described later.
The product G is placed at the time of the film folding operation by. <Structure of heat seal / film front / rear folding mechanism 70> The heat seal / film front / rear folding mechanism 70 operates after the left and right end portions of the film F covering the product G are folded under the product G, and is operated after the film F. This is a mechanism in which the end portion is folded under the product G, and the film F is sandwiched below the product G for heat sealing.

This mechanism 70 mainly comprises a rear folding plate 71.
And a rear folding plate moving mechanism, a rear clamp 53 and a rear clamp moving mechanism (described above), a front fixing member 72,
Front clamp 54 and front clamp moving mechanism (described above)
And a nichrome wire 81 and a thermistor 82 mounted on the front fixing member 72. The rear folding plate 71 is
Left and right pushing members 61, 62 and left and right folding plates 6 in the height direction
4 and 65, and the film F is folded from the back to the bottom side of the product G, and the front side fixing member 7
The film F is sandwiched between the two and the film F to give a pressing force necessary for heat sealing. The rear folding plate moving mechanism includes a rear folding plate moving motor 71a (see FIG. 4), a belt mechanism, a support member for supporting the rear folding plate, and the like. When the rear folding plate moving motor 71a operates according to a command from the control unit 90, the rear folding plate 71 moves back and forth.

The rear folding plate 71 has a main body 71c whose front surface is roughened in the range shown in FIG. 3 and has a rough surface. A bakelite member 71c is attached to the tip of the rear folding plate 71, as shown in FIG. The bakelite member 71c is made of a material having appropriate hardness, heat resistance, wear resistance, and insulation. With such a configuration, the portion of the rear folding plate 71 that comes into contact with the film F when the film F is folded is in a state in which the film F is hard to adhere.

The front side fixing member 72 is fixed to the body frame 15. The front side fixing member 72 is an aluminum plate 7
2a, a stainless plate 72b, and a roller 72c. Aluminum plate 72a is stainless steel plate 72b
And the roller 72c, and is arranged at a position sandwiched vertically. A nichrome wire 81 is attached to the rear surface of the aluminum plate 72a (the surface facing the rear folding plate 71). The nichrome wire 81 is located on the front side of the rear surface of the stainless plate 72b and the rear end of the roller 72c. To retract into
A stainless plate 72b and a roller 72c are arranged. Nichrome wire 81 (height dimension 2 mm) is made of aluminum plate 7
It is attached to the rear surface (height dimension 5 mm) of 2a via an insulating tape.

In order to estimate the amount of heat applied to the film F from the nichrome wire 81 by measuring the temperature of the aluminum plate 72a, the thermistor 8 which is a temperature sensor.
2 is embedded in the aluminum plate 72a. further,
The aluminum plate 72a is divided into two parts, left and right, and absorbs the expansion of the nichrome wire 81 according to the thermal expansion.

<Details of Operation of Stretch Wrapping Device 10> Next, in the operation of the stretch wrapping device 10, the film F
A detailed description will be given of the operation of folding the film F from the left and right to the bottom side of the product G and the operation of folding the film F from the rear to the bottom side of the product G to heat seal the film F. [Left and right folding operation and pushing operation] Fig. 10 (a)
As shown in FIG. 4, when the film F is transported by the film transport mechanism 40 above the lift mechanism 30, the left and right clamps 51, 52 are raised and the left and right pushing members 61, 6 are pushed.
The left and right parts of the film F are gripped between the two. At this time, the front and rear parts of the film F are also held by the front and rear clamps 53 and 54.

Next, the left and right pushing members 61, 62 and the left and right clamps 51, 52 following them are opened outward, and the film F is pre-stretched in the left and right direction (see FIG. 10B). At this time, the film F is also pre-stretched in the front-back direction. The lift mechanism 3 is applied to the film F that has been pre-stretched and wrinkle-free.
0 is the supporting members 34b, 36, 37 of the lift head 32,
The product G placed on 39 is lifted, and the film G is pushed up by the product G (see FIG. 10C). At this time, the commodity G is in a state in which the film F is pushed up and the upper side and the lateral sides are covered with the film F.

As shown in FIG. 10C, when the product G pushes up the film F, the left and right folding plates 64, 6
5 comes in first and folds the film in, and after a short delay, the left and right pushing members 61, 62 and the rear folding plate 71 also come in. And the left and right folding plates 6
4, 65 stop moving when they enter inside to a position where the bottom of the product G can be supported. On the other hand, the left and right pushing members 61, 62 and the left and right clamps 51, 52 which follow them are provided with the left and right folding plates 64, 65 so that excessive tension does not act on the film F due to the movement of the left and right folding plates 64, 65. Then, while moving inward, the left and right clamps 51 and 52 are lowered at appropriate positions to release the grip of the left and right portions of the film F (see FIG. 10D).

The left and right pushing members 61 and 62 continue to move inward even after the left and right portions of the film F are released, and finally move to a position inside the left and right folding plates 64 and 65. Stop (see FIG. 10 (e)). FIG. 11 shows the positional relationship between the left and right folding plates 64 and 65 and the left and right pushing members 61 and 62, and the rear folding plate 71 and the front side fixing member 72 in plan view at this time.

In the left and right folding operation,
Regarding the support of the product G by the lift mechanism 30, the support portion 34c of the central front-back support member 34b and the central support member 3 are provided.
7 continues to be supported by the support portion 37b, and the support portion 36b of the left and right central support member 36 and the left and right front and rear support members 39 are supported.
The support by the support portion 39b is replaced with the support by the left and right folding plates 64, 65 (see FIG. 16). Left and right folding plates 6
When 4, 65 enter the inside, the left and right center support members 3
The support portion 36b of 6 is pushed by the left and right folding plates 64 and 65 in order from the outer side, and pivots about the pin 36c to fall inward. Further, when the left and right folding plates 64, 65 come inward, the support portions 39b of the left and right front and rear support members 39 are formed.
Are sequentially pushed by the left and right folding plates 64 and 65 from the outer side, and fall as described above.

[Post Folding Operation and Heat Sealing Operation] FIG.
The product G and the film F in the state shown in 0 (e) and FIG. 11 are in a state as shown in FIG. 12 (a) in a side view. That is, the product G is the central front-back support member 3
4b, the support portion 34c of the central support member 37
(Here, the product G is not supported because the product G is short in the front-rear direction) and is supported by the left and right folding plates 64 and 65.

In the rear folding operation, first, the rear folding plate 71 moves forward, and after a short delay, the rear clamp 53 moves forward. After that, the rear clamp 53 moves forward in accordance with the movement of the rear folding plate 71 so that the excessive tension does not act on the film F (see FIG. 12B). When the rear folding plate 71 hits the supporting portion 34c of the central front-rear supporting member 34b on the rear side of the lift head 32, the rear folding plate 7
The lift head 32 as a whole starts to move forward by being pushed by the forward force from 1 (see FIG. 10C). At this time, the front and rear slider 31b to which the lift head 32 is fixed moves forward on the slide base 31.

Accordingly, as shown in FIG. 10 (d),
The product G also starts moving forward. In addition, the lift head 32
As the product G moves forward, in order to maintain the tension of the film F on the front side of the product G appropriately, the front clamp 5
4 begins to move backwards. Then, as shown in FIG. 10D, when the support portion 34c of the front central front-back support member 34b hits the front fixing member 72, the lift head 32 receives a compressive force from both front and rear, and the lift head 32
Begins to shrink in the front-back direction. Specifically, as shown in FIG.
As shown in (b), the force from both front and rear sides is applied to the support portion 34c.
And acting on the front and rear base 34 via the fixing portion 34d,
The state of the parallel link member 34a changes, and both front and rear bases 34 move diagonally downward so as to approach the central base 33. As a result of this movement, as shown in FIG. 15B, the supporting portion 39b in the dropped state enters the lower side of the supporting portion 36b in the collapsed state. Also, due to this movement, the central base 33
The fixing plate 33a and the front-rear base 34 are vertically overlapped (overlapped in plan view).

13 (a) and 14 show a product G supported by the lift head 32 and the folding plates 64, 65 in a state of being contracted back and forth. Here, the product G is
Center support member 3 for folding plates 64 and 65 and lift head 32
7 is supported only by the support portion 37b. The support portion 34c of the central front-back support member 34b of the lift head 32 moves diagonally downward as the lift head 32 contracts in the front-back direction, and thus does not support the bottom portion of the product G.

As shown in FIG. 13A, the lift head 3
When 2 has been contracted back and forth, the entire lift head 32 descends along the vertical rail 30a according to a command from the control unit 90. As shown in FIG. 13B, the rear folding plate 71 and the rear clamp 53 that continue to move forward enter into the space created by the lowering of the lift head 32. That is, when the lift head 32 descends, the product G
There is nothing that prevents the rear folding plate 71 and the rear clamp 53 from entering below the rear folding plate 71, and the rear folding plate 71 and the rear clamp 53 move further forward. Also at this time,
The product G that receives a forward force from the rear folding plate 71 via the film F slides on the left and right folding plates 64 and 65 and continues to move forward.

Finally, the rear folding plate 71 hits the front fixing member 72, specifically, the bakelite member 71c of the rear folding plate 71 hits the nichrome wire 81 of the front fixing member 72, and the front film F The film F on the rear side is heat-sealed below the product G by pressing force and heat input from the nichrome wire 81 (see FIG. 13C). It should be noted that the rear clamp 53 and the front clamp 54 are provided at or immediately before the heat input from the nichrome wire 81.
The holding of the film F by is released. This is to prevent the tension of the film F from changing when heat is applied.

After that, the rear folding plate 71 and the rear clamp 53 return to the rear (see FIG. 13D), and the product G covered with the film F and heat-sealed is the left and right folding plates 64. , 65 is supported by the front portion thereof. <
Configuration of Control Unit 90 and Characteristic Control by Control Unit 90> The control unit 90 controls each mechanism 2 of the stretch wrapping device 10.
It controls the operations of 0, 30, 40, 50, 60, 66 and 70. The control unit 90 includes a storage unit 9 such as a RAM.
Have one.

External storage, manual input,
Alternatively, the information about the product G and the information about the film F collected by the input from the scale 29 or the like are stored. [Control for left-right folding operation and pushing operation]
The control unit 90 controls the film pushing motor 63a and the left and right folding motor 68a based on the control data including the properties of the product G and the film F stored in the storage unit 91, so that the left and right pushing members 61 and 62 are connected to each other. Left and right folding plates 64, 6
The movement amount and the movement timing of No. 5 are optimal for the product G and the film F. As the control data, data regarding whether or not the product G includes a tray, the product G
Alternatively, data regarding the shape of the tray, data regarding the size of the product G or the tray, data regarding the rigidity of the product G or the tray, data regarding the size of the film F, and data regarding the type of the film F are included. Size, film type, tray depth / width / height, tray softness, shape of product G (round, etc.), height of product G, whether product G is on a hard tray or on a soft tray Or control data consisting of information on whether the product G is to be packaged without a tray is used.

Further, the timing for releasing the grip of the left and right portions of the film F in the lateral pushing operation, that is, the timing for lowering the left and right clamps 51, 52 is also controlled based on the above control data. [Control Regarding Rear Folding Operation] The control unit 90, based on the information on the properties of the product G and the film F in the storage unit 91,
The rear folding plate moving motor 71a, the rear clamp front-rear movement motor 55a, and the front clamp front-rear movement motor 56a are controlled. Specifically, the rear folding plate 7 driven by the rear folding plate moving motor 71a is provided so that excessive tension does not act on the film F.
In order to control the rear clamp forward / backward motor 55a that moves the rear clamp 53 in accordance with the movement of No. 1, and to keep the tension of the front film F, which changes due to the forward movement of the product G, within a proper range. The front clamp forward / rearward movement motor 56a that moves 54 is controlled. This allows
It is possible to prevent the film F from being excessively tensioned to form holes in the film F and the product G from being subjected to an excessive force.

[Control Regarding Heat Sealing Operation] Control Unit 90
When the front film F and the rear film F are sandwiched by the rear folding plate 71 and the front fixing member 72 below the product G, nichrome produces a large voltage or current (impulse) that lasts for a very short time. Heat is applied to the film F by flowing it through the wire 81. That is, here, an impulse seal capable of changing the amount of heat input to the heat-sealed portion with good responsiveness is employed.

Then, the control unit 90 controls the front side fixing member 72.
Based on the temperature measured by the thermistor 82 embedded in the aluminum plate 72a, at least one of the current value, voltage value, number of times, and energization time of the impulse flowing through the nichrome wire 81 is changed. Therefore, the film F can be heat-sealed with a sufficient amount of heat input. For example, when the temperature of the front side fixing member 72 rises and falls due to changes in the surrounding environment, the temperature change is measured by the thermistor 82, so the nichrome wire 81 is controlled so that heat sealing is appropriately performed. be able to. Specifically, when the ambient temperature is low in winter, the temperature of the aluminum plate 72a may be lowered and the amount of heat required for heat sealing may be insufficient. Therefore, the impulse seal is controlled to compensate for this.

<Characteristics of Stretch Wrapping Device 10> (1) In the stretch wrapping device 10, the lift head 32 of the lift mechanism 30 includes the central base 33, the front and rear bases 34, and the support members 3 extending upward from the bases 33, 34.
4b, 36, 37, 39. And
During the rearward folding operation, the central base 33 and the front-rear base 34 are moved relative to each other so that the bases 33, 34 and the support members 34b, 37 contract in plan view.

As a result, even if the rear folding plate 71 and the rear clamp 53 come into the bottom side of the product G during the rear folding operation, the bases 33, 34 and the supporting members 34b, 37 contract, so that the central supporting member 37. With the support portion 37b, the state in which the product G is supported can be maintained as long as possible. Further, the relative movement of the central base 33 and the front-rear base 34 avoids the interference between the support members 34b, 37 and the rear folding plate 71 or the rear clamp 53. Since it is not necessary to tilt the support member 34c to the front, the supporting portion 34c of the central front-rear supporting member 34b can be formed long in the front-rear direction. When the support portion 34c is tilted, if the support portion 34c is lengthened in the front-rear direction, the support portion 34c
When tilted, the end of the support portion 34c is lifted and the stability of the support state of the product G is lost.

(2) In the stretch wrapping device 10, the left and right folding plates 64 and 65 come inward in the left and right folding operation, and a horizontal force is applied from the folding plates 64 and 65 to the support portion of the left and right center support member 36. 36b and the support portion 39b of the left and right side front and rear support members 39, the support portion 3
6b falls inward and is disengaged from the movement path of the folding plates 64 and 65, and the supporting portion 39b falls and falls into the folding plates 64 and 6.
It deviates from the movement route of 5. That is, the support portion 39b, which is higher than the support portion 36b, has a structure in which the support portion 39b falls laterally with respect to the fixing member 38 and does not fall. Therefore, the arrangement pitch of the support portions 39b in the left-right direction can be set small. In this way, since the bottom of the product G is stably supported, even if the product G is a bare product without a tray or a product placed on a soft tray, the product G is hardly deformed or damaged. It is packaged without it.

(3) In the stretch wrapping device 10, the left and right folding plates 64 and 65 come inward in the left and right folding operation, and a horizontal force is applied from the folding plates 64 and 65 to the supporting portions of the left and right front and rear supporting members 39. When acting on 39b,
The pin 39c, which has been locked from above to the locked portion 38b of the fixing member 38, is displaced inward, so that the support portion 39b and the frame 3
9a falls. That is, the upper surface of the support portion 39b of the left and right front and rear support members 39 is structured so as to avoid the interference with the folding plates 64 and 65 by falling horizontally.
Therefore, the upper surface of the support portion 39b that supports the product G hardly moves upward, and the risk of deforming or damaging the product G is reduced.

[Other Embodiments] (A) In the above embodiment, the lift head 32 of the lift mechanism 30 is moved forward while being pushed by the rear folding plate 71. However, the lift head 32 is exclusively driven. It is also possible to adopt a configuration in which the device is moved back and forth.

(B) In the above embodiment, the central base 33
On the other hand, the front-rear base 34 moves diagonally downward and the lift head 32 contracts back and forth. However, the front-rear base horizontally moves with respect to the central base and the lift head contracts back and forth. It is possible.

(C) In the above embodiment, the lift head 3
Although the whole 2 adopts a configuration in which it moves forward on the slide base 31, the lift head 32 is directly fixed to the slide base 31, and the lift head 32 as a whole does not move back and forth (does not move in a plane). Is also possible. Also in this case, the rear front-rear base 34 moves obliquely downward with respect to the central base 33, so that the rear folding plate 71 and the rear clamp 53 may enter the bottom side of the product G during the rear folding operation. With the support portion 37b of the central support member 37, the state of supporting the product G can be maintained as long as possible.

[0066]

According to the present invention, when the film is folded by the folding mechanism, when the force including the horizontal component is applied to the predetermined supporting member from the folding mechanism, the predetermined supporting member is contracted in the vertical direction. As described above, since the structure in which the predetermined support member is vertically contracted is used instead of the conventional structure in which the predetermined support member is tilted, it is not necessary to secure a space for the predetermined support member to be tilted. Therefore, it is possible to reduce the arrangement pitch of the plurality of support members including the predetermined support member and the other support members. This makes it possible to more stably support the bottom of the product to be packaged, and even if the product to be packaged is a bare product without a tray or a product placed on a soft tray, the product will not be deformed or deformed. Packaging is started with almost no damage.

[Brief description of drawings]

FIG. 1 is a schematic side view of a stretch wrapping device.

FIG. 2 is a schematic front view of the stretch wrapping device (II-I in FIG. 1).
(I arrow view).

FIG. 3 is a schematic plan view of a stretch wrapping device.

FIG. 4 is a control block diagram of the stretch wrapping device.

FIG. 5 is a side view of a lift head of a lift mechanism.

FIG. 6 is a front view of a lift head of a lift mechanism.

FIG. 7 is a top view of a lift head of a lift mechanism.

FIG. 8 is a view on arrow VIII-VIII in FIG.

FIG. 9A is a diagram showing parameters in the initial position adjustment of the left and right clamps. (B) The figure which shows the joining part of a left clamp and a left pushing member.

FIG. 10 is a diagram showing a left-right folding operation and a pushing operation.

FIG. 11 is a schematic plan view when the left-right folding is completed.

FIG. 12 is a diagram showing a rear folding operation.

FIG. 13 is a diagram showing a rear folding operation and a heat sealing operation.

FIG. 14 is a schematic plan view showing the post-folding operation.

FIG. 15 (a) is a side view showing a state change of the lift head of the lift mechanism at the time of left / right folding and pushing operations. FIG. 6B is a side view showing a state change of the lift head of the lift mechanism at the time of rearward folding.

FIG. 16 is a front view showing a state change of the lift head of the lift mechanism during left-right folding and pushing operations.

[Explanation of symbols]

10 Stretch wrapping equipment 30 Lift mechanism 32 lift head 34 Front and rear base (base member) 34b Center front and rear support member (support member) 38 fixing member (first member) 38b Locked part 39 Left-right front-back support member (support member) 39b Support (second member) 39c pin (second member; locking part) 50 Film holding mechanism 60 Left and right film pushing mechanism (folding mechanism) 61,62 Left and right pushing member 64, 65 Left and right folding plates 66 Left and right folding mechanism (folding mechanism) F film G products (packaged items)

Claims (2)

[Claims] 1. A film holding mechanism for holding a film under tension, a base member, and a plurality of support members extending upward from the base member and supporting a bottom portion of an article to be packaged. Lift mechanism for pressing the packaged object against the film held by the film holding mechanism, and a folding mechanism for folding the peripheral portion of the film pressed against the packaged object by the lift mechanism to the bottom side of the packaged object When,
The packaging device, wherein at least one of the support members contracts in the vertical direction when a horizontal force is applied from the folding mechanism. 2. A first member fixed to the base member, wherein the support member contracts in the up-down direction.
A member, a locking portion that locks with the locked portion of the first member, and a second member that is located above the locking portion and that has a support surface that supports the object to be packaged. When a horizontal force acts on the second member from the folding mechanism, the locking of the locking portion with respect to the locked portion is released, and the second member moves downward. The packaging device according to claim 1.