JPH11255204A - Bag blocking apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out work of winding and blocking a mouth of a bag in a stable manner and increase the speed and efficiency of the work as a whole. SOLUTION: After a mouth Ba of a bag B with which flaps Aa of a case A are covered is wound upward by a windup mechanism, the mouth Ba of the bag B wound up is flattened in forward and backward directions by a flattening mechanism. By driving a deaerating mechanism, both side faces of the bag are pressed with press plates to perform deaeration and, by driving fore and rear winding mechanisms 7, a pair of winding bars 61 disposed forward and backward are moved horizontally in directions opposed to the fore and rear edges of the bag B. After inserting the flat side edges of the bag B between the paired winding bars 61, 61 by a suitable size, respectively, the paired winding bars 61 disposed forward and backward are rotated in the winding direction while lowering them. Since the mouth Ba of the bag B is wound suitable times to be blocked as it is being kept in a flat state, work of winding and blocking the mouth Ba of the bag B can be carried out efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for an operation of closing a synthetic resin or paper bag laid inside a container such as a cardboard, a synthetic resin, a metal or a wooden box. The present invention relates to a bag closing device to be used.

[0002]

2. Description of the Related Art Conventionally, as a device for closing the mouth of a bag laid inside a box as described above, for example, FIG.
As shown in FIG. 6, after the mouth portion Ba of the bag body B projecting upward from the flaps Aa of the box body A is tensioned in the front-rear direction, the bag body is moved in the direction facing one side edge of the bag body B. A pair of winding rods 71, 71 formed longer than the width of B are moved forward and backward in the horizontal direction, and the entire width of the bag body B is inserted between the pair of winding rods 71, 71. Thereafter, there is a device that rotates (in the direction of the arrow) while lowering the pair of winding rods 71, 71 to wind and close the mouth Ba of the bag body B.

[0003]

However, since the entire side surface of the bag body B is wound around the entire circumferential surface of the winding rods 71, the contact resistance generated at the mutually wound portions is large. When removing the winding rods 71 from the wound portion of the bag B, the box A may roll over or the bag B may be broken.

[0004] When the size of the bag B laid inside the box A increases, the winding rod 7 corresponding to the size of the bag B increases.
Since the total length of the winding rod 71 is increased, the strength becomes insufficient and the winding rod 71 is easily bent or deformed as the total length of the winding rod 71 increases, so that the bag size that can be wound is limited. and,
It is difficult to insert the bag B straight between the winding rods 71, 71, and the wound state of the bag B becomes uneven.

When the bag A is inserted between the pair of winding rods 71 and 71 or when the bag A is removed from between the winding rods 71, 71, the width of the bag B is smaller than the width of the bag B. Also wound rod 7
Since the strokes (moving distances) of the winding rods 71 and 71 must be lengthened, it takes a long time to move the winding rods 71 and 71 forward and backward, so that the working efficiency is poor and the winding ability is limited. ing.

[0006] In view of the above problems, the present invention winds the bag while holding the flat side edges of the bag with a pair of holding members.
An object of the present invention is to provide a bag closing device capable of stably performing a work of winding and closing a mouth portion of a bag body, speeding up the whole work and improving efficiency.

[0007]

According to the first aspect of the present invention,
A bag closing device for flattening a mouth portion of a bag laid in a container in a width direction, and then winding and closing the bag while keeping the mouth portion of the bag flat, comprising: A pair of holding members for holding the flat side edge of the bag body are provided facing the edge portion, and the pair of holding members are relatively moved in a direction facing the flat side edge portion of the bag body. A bag closing device provided with moving means, and provided with rotating means for rotating a pair of holding members holding both flat side edges of the bag body in a direction in which a mouth portion of the bag body is wound. Features.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, a bag sealing device is provided in which the holding member is formed to have a length such that a flat side edge of the bag body is held in a width direction. It is characterized by being.

According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, the flat side edge of the bag is provided at the end of the holding member facing the flat side edge of the bag. Is characterized in that it is a bag closing device in which an insertion portion for inserting the in the width direction is formed.

[0010]

In the bag closing device according to the first aspect, after the opening of the bag protruding above the peripheral edge on the opening side of the container is flattened and tightened in the width direction, the moving means is driven to drive the bag. After relatively moving the pair of holding members in the direction facing the flat side edges and holding the flat side edges of the bag evenly with the pair of holding members, the rotating means is driven to drive the bag body. The pair of holding members are rotated in one direction or the opposite direction while holding both flat side edges of the bag, and the bag is wound several times appropriately while the mouth of the bag is kept flat, so that the bag is wound. The work of resealing can be performed efficiently.

In the bag closing device according to the second aspect, in addition to the operation according to the first aspect, the flat side edge of the bag is held by the holding member in an appropriate length in the width direction. The moving distance is shorter than maintaining the full width, and the time required for forward and backward movement is greatly reduced.

According to a third aspect of the present invention, in addition to the operation of the first or second aspect, the flat side edge of the bag is inserted into the insertion portion formed in the holding member in the width direction and held. Therefore, the work of inserting and removing the flat side edge of the bag body can be easily performed.

[0013]

According to the present invention, the flat side edges of the bag body are uniformly held by the pair of holding members and wound.
Rather than winding the bag with a long winding rod like the conventional example,
The contact resistance applied to the holding member is small, and when the holding member is pulled out from the wound portion of the bag, the box can be reliably prevented from rolling over or the bag from being torn, The operation of winding and closing the opening can be stably performed.

Further, it is not necessary to hold the entire width of the bag body, so that the holding member can be formed shorter than a long winding rod as in the conventional example, and the strength required for the winding operation is reduced. As a result, the bag can be uniformly wound without bending or deformation, and can be used for the operation of winding and closing bags of various sizes.

Further, since the flat side edge of the bag is held by the holding member by an appropriate length, the moving distance of the holding member is shorter than that of holding the entire width of the bag, and the time required for the forward and backward movements is reduced. Since it is greatly shortened, the operation of winding and closing the mouth of one bag can be performed in a short time, and the speed of the entire operation and the efficiency can be improved.

Furthermore, since the flat side edge of the bag is inserted into the insertion portion formed in the holding member and wound, the operation of inserting and removing the flat side edge of the bag is easy. It is possible to reduce the labor for winding the bag.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. The drawings show, as an example of a container, a bag closing device used for an operation of closing a mouth portion of a bag laid inside a box, and in FIGS. 1 and 2, the bag closing device 1 Below the winding position set on the upper part 2, an elevating mechanism 3 that raises the bag A already laid in the bag at an appropriate height is disposed, and on both sides thereof, the bag B laid inside the box A is provided. Mouth Ba
A winding mechanism 4 that winds the above upward is provided. Above the winding position, a flat mechanism 5 for flattening the mouth Ba of the rolled bag B in the front-rear direction (transport direction) is disposed, and pressing both sides of the bag B on both sides thereof. A degassing mechanism 6 for evacuating the airbag is provided, and before and after the winding position, the mouth portion B of the flattened bag body B is provided.
A winding mechanism 7 for winding and closing a is provided, and in the upper central portion,
An insertion mechanism 8 for inserting the wound portion of the bag B along the front and rear inner wall surfaces of the box A is provided.

The box A is a square open form (for example, a square)
A bag B made of a transparent or translucent synthetic resin film is opened and laid in the inside of the box A assembled in the above manner, and flaps Aa formed on the opening side peripheral portion of the box A are provided.
In addition, the mouth Ba of the bag body B is folded back in a double-folded state or a single-folded state to cover. Note that, inside the bag body B, for example, fats and oils such as margarine, butter, and jam, food raw materials, coating raw materials, metal parts, and other stored items are appropriately stored.

The transport conveyor 2 has a number of feed rollers 1 between mounting frames 14, 14 erected in parallel to the transport direction.
5 are mounted on the feed rollers 15 at a predetermined interval in the transport direction, and the feed rollers 15 are rotated in the transport direction by the driving force of a rotation motor with a reduction gear (not shown). The transported box A is transported toward the winding position.

And a stopper 1 disposed immediately before the winding position.
6 is a stopper 1 disposed on both sides of the winding position, which is operated by a retracting cylinder 17 connected to the lower end thereof.
8 is moved forward and backward by an advancing and retreating cylinder 19 connected to a rear end of the box A. The subsequent box A conveyed to the winding position is temporarily stopped by the stopper 16, and the box A conveyed to the winding position.
Is temporarily stopped by the stoppers 18 and 18.

The elevating mechanism 3 is provided with erecting stands 20a, which are spaced apart from the above-mentioned feed rollers 15 on the upper surface side of the elevating table 20 arranged below the winding position. The rod end of the elevating cylinder 21 is vertically fixed to the rear end on the upper surface side of the table 20, and the elevating cylinder 21 is mounted on one side of the screw shaft 22 vertically mounted on the side so as to be vertically movable. .

The elevating table 20 is moved up and down by the elevating cylinder 21, and the elevating motor 2 with a speed reducer disposed on one lower side is provided.
3, the screw shaft 22 is rotated forward / reverse via the gears 23a and 23b, and the receiving position of the receiving table 20a is projected above the conveying surface of the feed roller 15, and the descending position of being immersed below the conveying surface. At the same time, the elevating platform 20 is lifted and stopped.
The elevating table 20 is moved up and down to an arbitrary height according to the size of.

As shown in FIGS. 3 and 4, the hoisting mechanism 4 pivotally supports a swing frame 25 on both sides below the winding position so as to be able to swing left and right, and is disposed on the side of the swing frame 25. The rod end of the provided swing cylinder 26 is connected to the swing frame 25, and the rod end of the lifting cylinder 27 vertically fixed to the side surface of the swing frame 25 is slightly smaller than the side surface of the box A. It is fixed to the lower end of a winding plate 28 formed in a shape and shape.

The oscillating cylinder 26 is mounted on the lift 20
The swing frame moves between a closed angle position where the hoisting plate 28 is in contact with the lower side surface of the box A lifted by the above, and an open angle position where the hoisting plate 28 is separated from the lower side surface by a predetermined distance. 27 is swung left and right.

The lifting / lowering cylinder 27 is positioned at a lower position facing the lower side surface of the box A stopped at the winding position and at a position above the flaps Aa of the box A lifted by the lift 20. The hoisting plate 28 is moved up and down to the ascending position where the mouth portion Ba of B is wound up.

As shown in FIGS. 5 and 6, the flat mechanism 5
A mounting frame 30 is erected above the winding position, and the rod end of the lifting cylinder 31 vertically fixed to the center of the upper surface side of the mounting frame 30 is fixed to the upper surface side middle portion of the U-shaped movable frame 32. The rod end of the rotation cylinder 33 attached to the front and rear ends of the movable frame 32 is connected to the base end of a tension rod 34 pivotally attached to the frame end.

The lifting / lowering cylinder 31 is provided with a tension rod at a lower position where it is inserted between the front and rear flaps Aa of the box A lifted by the lifting table 20 and at an upper position where it is withdrawn above the flaps Aa. 34 is moved up and down.

The rotation cylinder 33 is closed between the front and rear flaps Aa, Aa of the box A, the front and rear flaps Aa, Aa are opened at an appropriate angle, and the opening B of the bag B is opened.
The tension bar 34 is rotated back and forth between an open angle position where a is held in a flat state and a tension state.

The tension bar 34 is formed of a hollow tube member having a length that can be inserted into the mouth Ba of the bag body B wound up by the hoisting mechanism 4, and has a lower end on the insertion side. ,
A hole (not shown) for sucking the atmosphere in the bag B is formed.

The proximal end of the tension rod 34 is connected to a suction device (not shown) such as a suction blower or a vacuum pump.
When inserting into the bag body B, the negative pressure by a suction device is interrupted or stopped. On the other hand, the blocking or stop is released and the bag B
The inside atmosphere is suctioned, and an atmosphere containing, for example, dust, dust, etc., is discharged to the atmosphere side via, for example, a dust collector, a filter, or the like, or is appropriately collected by a collection unit (not shown). In addition, you may use the tension | tensile_rod 34 which pipe | tubes the pipe member along the side surface of a rod-shaped member.

The deaeration mechanism 6 has a mounting frame 36 installed in the upper part on both sides of the winding position in parallel with the transport direction, and a vertically moving cylinder 37 fixed vertically to the center of the upper surface of the mounting frame 36 has a rod end. Is connected to the rear end on the upper surface side of the movable frame 38,
The pressing plate 40 is moved up and down between a rising position where the operation of the hoisting mechanism 4 is allowed and a descending position where it is approached or pressed against the upper surface side of the storage items (not shown) stored in the bag body B.

An advancing / retracting cylinder 39 horizontally fixed to the lower central portion of the movable frame 38 has its rod end connected to the upper rear end of the pressing plate 40 so that the mechanisms 4, 5, 7, and 8 operate. The retreat position, which is an allowable interval and is vertically inserted along the inner wall surfaces of the left and right flaps Aa, Aa formed on the box A, and the opening inner wall surface of the flattened bag body B by the flattening mechanism 5 are brought into close contact. The pressing plate 40 is moved forward and backward to the forward position.

At the lower end of the pressing plate 40, a pressing roller 41 is pivotally supported in opposition to the left and right flaps Aa of the bag B laid inside the box A. The pressing roller 42 is supported so as to face the flap Aa. The pressing plate 40 is pressed against the side surface of the bag B by the pressing roller 4.
1, 42 are inclined or urged in the direction to be pressed first.

Since the winding mechanism 7 provided at the front and rear portions of the winding position is the same, the configuration of the winding mechanism 7 provided at the rear will be described.

As shown in FIGS. 1, 7 and 8, the winding mechanism 7 has a mounting frame 52 installed parallel to the transport direction on the side of the winding position, and installed on the front side of the mounting frame 52. Rail 5
The movable table 54 is attached to the front and rear sides of the movable table 54 so that the movable table 54 can move back and forth.
Is mounted so as to be vertically movable, and a rotatable table 59 is rotatably supported at the tip of a support arm 58 fixed to the front side of the elevating table 57. The flat side edges of the body B are spaced at intervals that allow insertion, and the winding rods 61, 61 formed to have a length that allows the flat side edges to be held, are horizontally fixed.

The forward / backward cylinder 62 fixed to the side of the mounting frame 52 has its rod end connected to the side end of the movable base 54 so that the flat side edge of the bag body B flattened by the flattening mechanism 5 is formed. The movable table 54 is moved back and forth between a forward position where it is inserted between the winding rods 61 and a retracted position where the flat side edge of the bag body B is pulled out from between the winding rods 61 and 61.

The lifting cylinder 63 fixed to the upper end of the movable base 54 has its rod end connected to the upper end of the lifting base 57, and the mouth Ba of the bag body B is wound by winding rods 61, 61. The starting position (up position) to be turned and the mouth B of the bag B
The elevating platform 57 is located at an end position (a descent position) where a is wound several times (for example, about 3 to about 6 times) by the winding rods 61, 61 as appropriate.
Move up and down.

The mouth Ba of the bag body B is wound via the pinion 64, the rack 65, the pulleys 66, 66, and the drive chain 67 in accordance with the vertical movement of the lift 57. The turntable 59 and the winding rods 61, 61 are rotated in the winding direction.

As shown in FIGS. 5 and 6, the insertion mechanism 8 fixes the rod end of the lifting cylinder 70 vertically fixed to the lower surface center of the mounting frame 30 to the upper surface center of the lifting frame 71. , At the front and rear ends of the elevating frame 71, a gap inserted between the front and rear facing wall surfaces of the box body A and the bag body B, and formed to have a size and a plate thickness that can be inserted between the facing wall surfaces. The insertion plate 72 is vertically fixed.

The lifting cylinder 70 is mounted on the lifting table 20.
The lowering position where the insertion plate 72 is vertically inserted between the front and rear inner wall surfaces of the box A lifted by the above and the front and rear outer wall surfaces of the bag body B, and the operation of the mechanisms 3, 4, 5, 6, 7 The insertion plate 72 is moved up and down to a raised position where it is allowed and is pulled out above the flaps Aa.

A support plate 73 is provided between the lower surfaces of the insertion plates 72, 72 facing the lower end, and the lower ends of the support shafts 74, which are vertically mounted on both lower end portions of the support plate 73, are attached to the inside of the box A. And is fixed to the upper surface side of a pressing plate 75 formed to have a size and a shape to which the bag body B is pressed.
Are biased in a direction in which the coil spring 76 is pressed against the bag body B by the elasticity of the coil spring 76 mounted on the shaft peripheral surface on the lower end side.

The illustrated embodiment is constructed as described above, and the operation of the bag closing device 1 for winding and closing the mouth Ba of the bag B laid inside the box A will be described below. First, as shown in FIGS.
After stopping the transport of the box A to the upper winding position, as shown in FIG. 9, the lifting mechanism 3 is driven, and the box A on which the bags are laid is once lifted to a predetermined height by the lifting platform 20 to be flattened. The tension rods 34, 34 of the mechanism 5 are inserted between the front and rear flaps Aa, Aa of the box body A in the closed angle state.

Next, as shown in FIGS. 4 and 10, the hoisting mechanism 4 is driven to press the hoisting plates 28, 28 against both lower side surfaces of the box A lifted by the lift 20. Box A
The mouth Ba of the bag body B covered with the flaps Aa.

At the same time, as shown in FIGS. 5 and 11, the flat mechanism 5 is driven so that the mouth Ba of the bag body B wound up by the hoisting plates 28, 28 is moved in the front-rear direction by the tension rods 34, 34. After flattening and tensioning, the front and rear flaps Aa of the box A are bent in the front and rear direction by the tension rods 34,34. Thereafter, the hoisting plates 28 and 38 are returned to the initial positions.

Next, as shown in FIGS. 6 and 12, the degassing mechanism 6 is driven to insert the pressing plates 40, 40 along the left and right flaps Aa, Aa of the box A, and the bag B is inserted into the bag B. The pressing roller 41 approaches or presses against the upper surface side of the stored item (not shown). At the same time, the pressing roller 42, 42
The front and rear flaps Aa, Aa are bent in the front and rear direction.

Next, the pressing plates 40, 40 are horizontally moved in a direction opposite to both side surfaces on the opening side of the bag B, and
Presses both side surfaces of the bag body B against the upper surface side of the storage object (not shown), and presses the inner wall surface of the opening side of the bag body B with the pressing plate 4.
At 0, 40, the atmosphere inside the bag body B is degassed in order from the lower side. The mouth Ba of the bag B may be heated and welded by, for example, a heater.

At the same time, the tension bars 34, 34 are lifted while the mouth Ba of the bag B is flattened in the front-rear direction.
The atmosphere inside the bag B is forcibly suctioned by the suction device (not shown) through the tension rods 34, 34, and the inner wall surface of the bag B is brought into close contact. Tightening rods 34, 3
After maintaining the flat state in step 4, the pressing plates 40, 40 are returned to the initial position.

Next, as shown in FIGS. 13 and 14, the front and rear winding mechanism 7 is driven so that the front and rear edges of the flat bag body B are inserted by the tension rods 34 and 34 in the front and rear directions. Is relatively moved, and the flat side edge of the bag body B is inserted between the winding rods 61, 61, respectively.

The mouth portion Ba of the bag body B is
Then, the front and rear winding rods 61 are rotated obliquely downward (in the direction of the arrow) while being lowered obliquely, and the mouth Ba of the bag body B is rotated.
Is wound flatly several times while being kept flat and closed. After the end of the winding, the pair of winding rods 61, 61 disposed back and forth are retracted and returned to the initial position, and the winding rods 61, 61 are respectively extracted from the front and rear edges of the wound bag body B.

Next, as shown in FIG.
Is driven to insert the insertion plate 72 between the front and rear opposing wall surfaces of the box A and the bag B, and the front and rear ends of the wound bag B are box A
And between the front and rear opposing wall surfaces of the bag B, and pressing the pressing plates 75 against the upper surface of the bag B, respectively, to press and shape the upper surface of the bag B flat, and then insert the insertion plate 72 and Press plate 7
5 is returned to the initial position. Thereafter, the elevating platform 20 is lowered, and the box A with the bag closed is transported and supplied to the next step (for example, the box A sealing step) by the transport conveyor 2. In the same manner, the mechanisms 3, 4, 5, 6, 7, and 8 are driven to continue the operation of closing the bag B laid inside the next box A.

As described above, the front and rear edges of the bag body B flattened in the front-rear direction by the flat mechanism 5 are evenly held and closed by the pair of winding rods 61 provided in the front and rear. Therefore, the contact resistance given to the winding rod 61 is smaller than when the bag B is wound with a long winding rod as in the conventional example, and the winding rod 61, When removing 61, it is possible to reliably prevent the box body A from rolling over and the bag body B from being torn, and to stably wind and seal the mouth Ba of the bag body B.

Further, it is not necessary to hold the entire width of the bag B, so that the winding rod 61 can be formed to be shorter than the long winding rod as in the conventional example, and necessary for the winding operation. Since high strength is obtained, the bag B can be uniformly wound without bending or deformation, and can be used for winding and closing bags B of various sizes.

Further, the flat side edge of the bag B is held by the pair of winding rods 61, 61 for an appropriate length.
Since the moving distance of the winding rods 61, 61 is shorter and the time required for the reciprocating movement is greatly reduced as compared with the case where the entire width of the bag B is inserted, the operation of winding and closing the mouth Ba of one bag B is closed. Can be performed in a short time, and the speed of the entire operation and the efficiency can be improved.

Furthermore, since the flat side edge of the bag B is inserted between the winding rods 61 and wound, the work of inserting and removing the flat side edge of the bag B is performed. Can be easily performed, and labor for winding the bag body B can be saved.

In the correspondence between the configuration of the present invention and the above-described embodiment, the container of the present invention corresponds to the box A of the embodiment, and similarly, the holding member corresponds to the winding rod 61, The insertion portion of the holding member corresponds to the space formed between the winding rods 61, and the moving means includes the mounting frame 52 and the rail 5
3 and the movable table 54, and the rotating means is a rail 5
5, 56, a lift 57, a support arm 58, a turntable 59, a lift cylinder 63, a pinion 64, a rack 65, a sprocket 66, and a drive chain 67. Is not limited only to the configuration of the above embodiment.

In the embodiment described above, the flap A
a ... The mouth portion Ba of the bag body B covered with a ... is wound up and then closed. For example, the mouth portion of the bag body B laid so as to protrude above the flaps Aa ... of the box body A. The present invention can also be applied to the operation of winding and closing Ba, and is not limited to only the use as in the embodiment.

Further, instead of the winding rods 61, 61, the front and rear edges of the bag body B are held and wound by a holding member (not shown) formed in, for example, a U-shape, an H-shape or another similar shape. You may block.

[Brief description of the drawings]

FIG. 1 is a side view showing an arrangement state of each mechanism constituting a bag closing device.

FIG. 2 is a side view showing an arrangement state of each mechanism.

FIG. 3 is a plan view showing a transfer operation by a transfer conveyor.

FIG. 4 is a side view showing a hoisting operation by the hoisting mechanism.

FIG. 5 is a side view showing a flattening operation by the flattening mechanism.

FIG. 6 is a side view showing a pressing operation by the deaeration mechanism.

FIG. 7 is a plan view showing an advancing and retracting operation of a winding rod constituting the winding mechanism.

FIG. 8 is a side view showing the elevating operation of the winding rod.

FIG. 9 is a side view showing a state where a tension rod is inserted into the inside of the box.

FIG. 10 is a front view showing a hoisting operation by the hoisting mechanism.

FIG. 11 is a side view showing a flattening operation by the flattening mechanism.

FIG. 12 is a side view showing a pressing operation and a deaeration operation by the deaeration mechanism.

FIG. 13 is a side view showing the winding operation by the front and rear winding mechanisms.

FIG. 14 is a plan view showing a winding operation by a winding rod.

FIG. 15 is a side view showing the insertion operation by the insertion mechanism.

FIG. 16 is a side view showing a conventional bag closing method.

[Explanation of symbols]

 A: Box body Aa: Flap B: Bag body Ba: Mouth 1: Bag closing device 2: Transport conveyor 3: Lifting mechanism 4: Lifting mechanism 5: Flat mechanism 6: Degassing mechanism 7: Winding mechanism 8: Insert Mechanism 20 ... Elevating table 28 ... Hoisting plate 34 ... Tension bar 40 ... Pressing plate 61 ... Winding bar 72 ... Insert plate

Claims (3)

[Claims] 1. A bag closing device for flattening a mouth portion of a bag laid inside a container in a width direction, and then winding and closing the bag while keeping the mouth portion of the bag flat. A pair of holding members for holding the flat side edges of the bag body are disposed opposite to the flat side edges of the body, and the pair of holding members are held by the flat side edges of the bag body. Bag provided with moving means for relatively moving the pair of holding members holding both flat side edges of the bag, and rotating means for rotating the pair of holding members in a direction in which the mouth of the bag is wound. Sealing device. 2. The bag closing device according to claim 1, wherein said holding member is formed to have a length such that a flat side edge of said bag body is held in a width direction. 3. An insertion portion for inserting the flat side edge of the bag in the width direction is formed at an end of the holding member facing the flat side edge of the bag. Bag closing device.