JP3079988B2 - Stretch film packaging machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stretch film wrapping machine, and more particularly, to a film transfer means for pulling out and transferring a film from a film roll set in the wrapping machine while holding both side edges in the width direction of the film. And a stretch film packaging machine comprising:

[0002]

2. Description of the Related Art In a stretch film packaging machine for pulling out and transporting a film by sandwiching both side edges in the width direction of a film unwound from a film roll, when a film is fed at the time of setting the film roll or when an emergency stop is performed. Film over detection sensor in case that the user forgets to remove the unused film, or if the film is transported too far downstream from the predetermined position (packaging unit) for some reason (hereinafter referred to as film over). Is provided, and when the film over is detected, the driving of the film transporting means is stopped to prevent the film from being caught in the winding portion of the film transporting means.

[0003]

Incidentally, the above-mentioned film over detection sensor is arranged near the downstream end of the film transfer means because it is necessary to make the apparatus as small as possible. For this reason, when the transfer speed of the film transfer means is increased in order to improve the processing capacity of the apparatus, even if the drive of the transfer means is stopped immediately when the film over is detected by the sensor, it actually stops. By this time, it takes some time, during which the film is transferred, and the film may be wound around the winding portion of the film transferring means.

[0004] Once the film is wound into the winding portion of the film transport means, the film is twisted into a string shape, and becomes extremely strong against tension, so that an operator cannot easily remove the wound film. Pulling the film, the gripping belt for transferring the film breaks and the packaging machine cannot be used. In order to solve this problem, it is conceivable to arrange a member for preventing film wrapping on the front side of the winding portion of the film transport means, and it has been practically used in some cases. It could not be prevented. In addition, the above problem can be solved by disposing the above-mentioned sensor sufficiently downstream of the downstream end of the film transfer means, but there is a problem that the lateral width of the apparatus is increased accordingly.

[0005] The present invention has been made in view of the above-mentioned problems of the prior art.
It is an object of the present invention to provide a stretch film wrapping machine capable of effectively preventing the film from being rolled up at the time of film over without increasing the width of the wrapping machine.

[0006]

In order to achieve the above-mentioned object, the present invention provides a technical means in which a pair of film transporting means arranged so as to sandwich a packaging portion is provided in a width direction of a film unwound from a film roll. Draws and transfers the film necessary for packaging by sandwiching both side edges of the product, pushes up the product from below against the film stretched over the packaging portion, covers the upper surface of the product, and removes the end of the film. In a stretch film wrapping machine that folds at the bottom of the packaged object,
A detecting means for detecting that the transfer of the film is too far downstream of the packaging unit, when the detection means transfer film is detected that excessive downstream of the packaging unit, immediately the film transport means Control means for reversing, and packaging by reversing the film transport means
Film that has gone too far downstream
It is transported in the direction of the packaging position where the work is performed .

The above-mentioned film transfer means may be of a type comprising upper and lower belts and holding a film between the upper and lower belts, a type receiving one of the holding members and a type comprising a belt on the other, or an endless rotating type. Any type, such as a type in which a plurality of grippers are attached to a moving chain or belt or the like and a film is sandwiched by the grippers, may be used. The structure of the detection sensor may be a mechanical means for detecting the film by moving the actuator by the film, or a method for detecting the film without contact using a reflection sensor. And
The number of sensors to be installed is not limited to a configuration in which a pair (two) is provided inside a pair of film transport means, but three sensors are provided along a film width direction, or one sensor is provided at a position corresponding to a substantially central position of the film width. It is possible to do it appropriately.

Further, a member for preventing film wrapping may be provided at the downstream winding portion of the film transport means. Further, the detecting means may be provided in a pair near (in front of) the downstream winding portion of the film transport means, and the detecting means may also serve as a film wrap preventing member.
The configuration of the packaging machine is not limited as long as the packaging machine is of a type in which a pair of film transporting means arranged so as to sandwich the packaging portion sandwiches both side edges in the width direction of the film and pulls out and transports the film.

According to the above means, when the film over is detected by the detecting means, the film transporting means is immediately driven in the reverse direction to transport the film in the reverse direction, and the film is wound downstream of the film transporting means. Since the film is kept away from the winding portion, it is possible to prevent the film from being wound around the winding portion.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. The stretch film wrapping machine shown in FIGS. 1 and 2 is provided with a product placing section (measuring section) a on which a packaged material M is placed in front of a machine frame A, and the packaged package placed on the product placing section a. The object M is transported by the pusher conveyor B to the elevator 1 provided inside the machine frame A. Sensors (not shown) for measuring the width, depth (longitudinal width), and height of the article to be packaged are provided near and near the pusher conveyor B. A packaging part b is provided above the elevator 1, and a film 3 unwound from a film roll disposition part 2 and a film roll 3 set in the disposition part 2 is provided on a side (right side in FIG. 1) of the packaging part b. The film holding means C for holding the leading end of the film holding means C is provided. The film transferring means D for holding and pulling out the leading end of the film held by the film holding means C and transferring it to the packaging part b is provided by the film holding means C. A cutter E that is arranged close to the leading end and that is arranged between the film holding means C and the film transporting means D and cuts the film 3 ′ that has been nipped and pulled out by the film transporting means D into a predetermined length is disposed. I have. Above the film transfer means D, left and right folding plates 4 and 4 ', a rear folding plate 5, and a discharge pusher 6 are arranged above the rear folding plate 5.

Therefore, the article to be packaged M placed on the elevator 1 is pushed up against the film 3 'spread on the packaging section b by the elevation of the elevator 1, and the end of the film in the stretched state. The part, left and right folding plate 4,
After being folded into the bottom surface of the packaged object M by 4 ′ and the rear folding plate 5, the packaged object is horizontally pushed by the discharge pusher 6 toward the discharge section (heat sealing section) 7 on the front side of the machine frame A. Then, the front end of the film 3 'is folded by the front folding roller 7' into the bottom of the packaged object, and the folding of the film is completed. If the stretch wrapping machine is a weighing / packing price maker, a label is attached during transfer by the discharge pusher 6.

The film holding means C comprises a film 3 ′ of the film roll 3 set in the film roll placement section 2.
As shown in FIG. 1, a film receiving plate 8 erected and fixed over an endless belt 8 which is located below the film and arranged in parallel at a predetermined interval in the front-rear direction as shown in FIG. A holding plate 9 of the same shape for holding the film supported on the surface of the film receiving plate 8 ′ with the film receiving plate 8 ′, and a holding roller 10 attached to the film receiving plate 8 ′. , And the holding plate 9 is
, Is vertically slidably supported inside a protective cover 11 which is rotatable to open and close, and engages with a film receiving plate 8 ′ which is fixedly mounted on the endless belt 8 and slides up and down together. The end of the film 3 ′ sandwiched and held between the film receiving plate 8 ′ and the holding plate 9 can be transferred to the film transfer means D. The holding roller 10 attached to the film receiving plate 8 'has its outer surface fitted and projected into the through hole formed in the holding plate 9 from the through hole formed in the receiving plate 8' so as to remove the film 3 '. The film is made to meander along the peripheral surface of the holding roller 10 to reliably hold the film, and the holding roller 10 is configured to be rotatable only in the film pull-out direction.

The endless belt 8 is wound around a pulley fixed to a rotating shaft of a motor 12, a pulley 14 coaxial with a feeding roller (film supply roller) 13, and a driven pulley 15. The drive of the motor 12 causes the endless belt 8 to move up and down (forward / reverse rotation) along the moving direction of the film. Further, the driving of the feeding roller 13 for pulling out and supplying the film of the film roll 3 to the film holding means C is connected via a pulley to a driving system of a film transport means D described later, and an intermediate transmission pulley (not shown). In (2), a brake and a clutch are used, and the driving and stopping of the feeding roller are controlled separately from the film holding means C, and are controlled so as to stop simultaneously with the operation of the cutter for cutting the film. Furthermore, the film receiving plate 8 'constituting the film holding means C
A plurality of cutouts 16 are formed at the upper end of the holding plate 9 with reference to one end in the width direction so as to be able to correspond to film rolls having different film widths. The transfer of the film is performed. The film holding means C is divided into two in the width direction so that one or both of the holding means can be moved in the width direction in accordance with the film width so as to correspond to a film roll set in the film roll disposition unit 2. The configuration is arbitrary.

The film transport means D includes a pair of upper and lower endless elastic belts 17, which sandwich a lateral end of the film in the width direction.
17 ', a clamp plate 18 for pressing the lower elastic belt 17' against the upper elastic belt 17 side, and the starting end side of the lower elastic belt 17 'is inclined downward toward the film holding means C. And a pressing belt 19, which is disposed so as to overlap with the upper surface of the downwardly inclined starting end and whose opening and closing movement is possible at the distal end thereof, and sandwiches the packaging portion b as shown in FIG. It is arranged at a position for holding the side end of the film 3 ′ pulled out from the film roll 3 back and forth. The pair of front and rear components are supported by mounting frames 20, 20 ', and the mounting frames 20, 20' are disposed at right angles to the lower side of the mounting frames 20, 20 '.
The mounting frame 20, which is supported by the guide rods 21, 21 'of the book via connecting members 22, 22' and to which one of the film transport means D1 is mounted, is fixed and the mounting frame to which the other film transport means D2 is mounted. Reference numeral 20 'is configured to be movable along the guide rods 21, 21', and the film transport means D2 on the movable side thereof is provided.
Is connected to a distance extending means (not shown) so that the distance from the fixed-side film transport means D1 can be adjusted.

A pair of upper and lower endless elastic belts 17 and 17 'constituting the above-mentioned film transfer means are driven and rotated in the same direction so as to pinch and transport the film. The drive roller 17'a around which the lower elastic belt 17 'is wound rotates, and a chain sprocket (not shown) fixed to the shaft of the drive roller and the upper elastic belt 17 are wound. The power is transmitted by winding the chain around a chain sprocket (not shown) fixed to the shaft of the driving roller 17a, and the upper elastic belt
17 is also configured to rotate. Further, the clamp plate 18 for pressing the lower elastic belt 17 'against the upper elastic belt 17 is not limited to the illustrated three-division but may be divided into four or more, and such a clamp plate can be transported and expanded evenly. It is arranged so as to be symmetrical about the center of the packaging part b.

The cutter E for cutting the film drawn by the operation of the film transport means D and the feeding roller 13 into a predetermined length is substantially perpendicular to the film 3 'by a control means constituted by an electromagnetic solenoid 24. The film 3 ′ is configured to protrude and retract, and the film 3 ′ is configured to be cut by controlling the power supply to the electromagnetic solenoid 24.

As shown in FIGS. 4 to 6, the front and rear film transport means D1 in the film transport means D are used.
, D2, that is, inside the vicinity of the drive roller 17'a around which the lower elastic belt 17 'is wound in the front and rear film transfer means D1 and D2, also serves as a film winding prevention member 25. The film over detecting means F and F 'are mounted via brackets 26 to mounting frames 20 and 20' on which the film transferring means D1 and D2 are supported, respectively.

The film over detecting means F and F ', which also serve as the film entanglement preventing member 25, are
A turning piece 25a pivotally attached at 27 and a vertical standing piece 25c integrally formed on the turning piece 25a via a horizontal connecting portion 25b.
The top of the vertical standing piece 25c has a packaging part b
An eaves-like protrusion 25d is formed in the direction, and the protrusion 25d is arranged so as to protrude above the joining surface of the upper elastic belt 17 and the lower elastic belt 17 'holding the film as shown in FIG. Have been. Then, a coil spring 28 is stretched over the spring mounting portion projecting below the middle position of the rotating piece 25a and the bracket 26, and the film entanglement preventing member 25 is contacted with the film on the bracket 26. A stopper 29 for restricting the range of rotation of the film and a stopper 30 for stopping the film winding prevention member from returning to the initial state by the action of the coil spring 28 are fixed.

A sensor 31 is attached to the bracket at the position where the open end 25e of the rotating piece 25a of the film entanglement preventing member 25 is located so as to sandwich the open end 25e. When the film 3 'hits the vertical upright piece 25c, the rotation piece 25a of the prevention member 25 is rotated about the shaft 27. The operation of the film winding prevention member 25 can be detected by the sensor 31. Is configured. The film transport means D is configured to rotate in the reverse direction by the detection signal of the sensor 31.
That is, when the film 3 'conveyed by the film conveying means D goes too far downstream from the predetermined position, it is detected by the sensors 31 of the film over detecting means F and F' via the film entanglement preventing member 25. At the same time, the film 3 'transferred by the film transfer means D is received by the vertical upright piece 25c of the film winding-in prevention member 25 to prevent the film 3' from being wound into the downstream winding portion of the film transfer means D.

FIG. 7 shows the electrical configuration of the above-described apparatus. The apparatus includes a weighing label printer control unit G and a packaging mechanism control unit H. The weighing label printer control unit G mainly performs control related to the weighing label printer. Since it is not directly related to the present invention, illustration and description are omitted, and the packaging mechanism control unit H related to the present invention will be described. The packaging mechanism control section H mainly controls the mechanism section of the packaging machine, and has a C
Controlled by PU32.

The CPU 32 has a communication interface circuit (INF) 33, a ROM 34, a RAM 35,
The operation unit 36, the display unit 37, and the mechanism driving unit 38 are connected. The communication interface circuit (INF) 33 is a circuit for communicating various data and commands with the weighing label printer control unit G. The ROM 34 stores a control program executed by the CPU 32. RAM 35 is a CPU
32 stores various tables and the like for determining control data based on product shape data (length, width, height), in addition to various register and flag areas used when the control program of the ROM 34 is executed. I have. The operation unit 36 includes various switches for starting and stopping the apparatus and a keyboard for inputting data and the like. The display unit 37 is composed of a dot-type liquid crystal display, and displays input data, displays preset data,
It displays various messages such as "film over" and is also called a console unit.

The mechanism drive section 38 is a circuit for driving each mechanism section of the packaging machine when packaging is performed, and specifically, a motor 39 for driving the elevator 1 and a drive motor for the conveyor B for loading goods. 40, drive motor for film transfer means D
23, a drive motor 41 for operating left and right folding plates 4, 4 'for folding the left and right ends of the film into the bottom of the product, a drive motor 42 for operating the folding plate 5 for folding the rear end of the film into the bottom of the product, and discharging. There are a drive motor 43 for operating the pusher 6, film over detection sensors F and F ′, and a rotary encoder 45 for detecting a rotation angle of a cam 44 for driving the elevator 1. The film over detection sensors F and F 'detect whether or not the film 3' pulled out and transported by the pair of film transport means D exceeds a predetermined position (wrapping part b) (whether the film is over). CPU for film over
Supplied to 32. The configuration of the packaging machine has been briefly described above, but the details of control of other motors not directly related to the present invention will not be described. Above rotary encoder
45 is attached to the shaft of the cam 44 that drives the elevator,
The output pulses from the rotary encoder 45 are counted, and the rotation angle of the cam is detected based on the count value.
Then, based on the rotation angle of the cam, the [loading process]
Control of the [push-up step], [folding step], [unloading step], and [film transfer step] is performed. And cam
One rotation of the packaging machine completes one cycle of operation of the packaging machine. A status signal (such as normal or error) of each control unit is exchanged between the packaging mechanism control unit H and the weighing label printer control unit G (not shown).

Next, the mechanical time chart of the above-mentioned packaging machine will be described with reference to FIG. 8 for the operation in the case where the film transport means is stopped and the film is cut.
Switching between cutting the film with the film transporting means stopped or with the film transporting means being driven and rotated depends on the width of the film roll set in the film roll placement unit 2 and the packaging. Is determined by the depth dimension (vertical width) of the article to be packaged. Also, the driving and stopping of the feeding roller 13 for feeding the film, the operation of the cutter E,
Each control of the stop, the vertical movement of the film holding means C, and the drive / stop of the film transport means D is performed by a cam for driving the elevator 1.
The rotation is performed based on the rotation angle of 44. When the cam makes one rotation, the operation of one cycle of packaging is performed. The rotation angle of the cam is detected by counting the output pulses from the rotary encoder 45 attached to the cam shaft as described above, and detecting the count value.

(I) The article to be packaged M is placed on a product placing section (measuring section) a.
When the weighing is completed by placing on the, the drive motor 39 starts rotating. The cam 44 is rotated by the drive motor 39, and the elevator moves up and down at the timing shown by one rotation of the cam. If the depth dimension of the previously weighed packaged object that is waiting in the middle of the conveyor (before the elevator 1) is equal to or greater than a predetermined value, the mode in which the film transport unit D is stopped to cut the film is set; Set the drive motor 39 to the low speed mode. When the rotation of the drive motor 39 starts, the time chart starts from 0 °. (II) Conveyor B is immediately driven, and the packaged articles that have been placed last time and are waiting in the middle of the conveyor B are placed on the elevator 1 (simultaneously, the goods on the goods placing section a are transported to the middle of the conveyor B). I do.) (III) Almost simultaneously with the driving of the conveyor B, the pressing belt 20 of the film transport means D closes, and after the closing movement of the pressing belt 19 is completed, the film receiving plate 8 constituting the film holding means C
And the holding plate 9 are lowered integrally (the presser belt 19 is at the open position and the film holding means C is at the upper position at the initial position). (IV) Next, the film transport means D is driven, and the feed roller 13 is driven and rotated with a short delay to draw out a film having a length optimal for packaging the packaged object from the film roll 3 and then stopped at the same time. In addition, the length of the pulled out film is detected by measuring the amount of movement of the belt by providing an optical counter on the rotating shaft of the film transfer means D. Then, at the time of the film withdrawing operation of the film transport means D, the presence or absence of the film over is detected by the film over detection sensors F and F '(see the detection timing of FIG. 8). That is,
The operation of the film over detection shown in FIG. 9 described later is executed. (V) Next, the electromagnetic solenoid 24 for moving the cutter E to the film side is turned on, the cutter operates, and the stopped film 3 'is cut so as to have a clean straight cutting edge.

(VI) After the film is cut, the electromagnetic solenoid is turned off, the cutter E is returned to the original position, and the drive motor 23 of the film transfer means D is restarted to put the cut film into the packaging section b. The film transfer means D is moved by a predetermined amount so as to be located at the center, and then stopped. Also at the time of centering due to the movement of the film transport means D, the presence or absence of film over is detected by the film over detection sensors F and F '(see detection timing in FIG. 8).
That is, detection is performed at the same timing as the operation of the film transport means D. (VII) Simultaneously with the stop of the film transfer means D, one of the film transfer means D2 is moved away from the other film transfer means D1 to start expanding the film, and the expansion is completed before the elevator 1 rises. I do. During this time, the rear folding plate 5 and the left and right folding plates 4, 4 'are in the most opened state. Then, the operation of the conveyor B is also completed, and the “width” is detected in the early stage of the loading of the packaged object measured this time, and the “depth dimension” is detected in the latter period, and the middle of the elevator B (elevator 1) is detected.
Before). (VIII) When the elevator 1 starts to ascend and reaches the top, the closing movement of the rear folding plate 5 and the left and right folding plates 4 and 4 'is started, and the movable side of the film transport means D for expanding the film is moved. The film transfer means D2 starts to move in the closing direction. This movable-side film transfer means D
By moving 2 in the closing direction to weaken the film expansion, the tensile strength of the film is reduced.

(IX) When the folding of the end of the film is completed, the starting end of the pressing belt 19 provided above the starting end of the film transferring means D rotates upward, and then the film holding means C is moved by the film transferring means D. Be raised to the side. At this time, the feeding roller 13 is freely rotated, and the holding roller provided on the film holding means C holds the film.
Is pulled out, and the leading end of the film is located between the lower elastic belt 17 ′ and the pressing belt 19 in the film transport means D. Thus, the film can be pulled out by the next film transport means D, and one packaging cycle is completed.

FIG. 9 is a flowchart showing the control of the detection of over-transfer of the film, which is performed every time the film is transported, and is executed by the CPU. (Start): At the start of the operation of the film transfer means D, this processing starts. When the front end of the film 3 'is pinched. (SP1) ... The film transfer means drive motor (stepping motor) is driven forward by one step (one pulse). Thus, the film is pulled out and transferred. (SP2): It is checked whether or not the film over detecting means F, F '(sensor 31) has detected the film over. (NO) → to (SP3) (YES) → to (SP4) (SP3) ... Is the film withdrawal / transfer completed? That is, it is checked whether or not the film has been drawn out and transferred by a predetermined amount. (NO) → to (SP1) (YES) → to (end) (SP4) ... Sets a flag indicating that a film over has occurred, and issues an alarm indicating that a film over has occurred. The content of the warning is displayed, for example, in characters on the display unit of the packaging machine. This is indicated by characters on the display of the printer. Turn on a lamp that indicates that film over has occurred. Sounds a buzzer indicating that a film over has occurred. It warns by voice that film over has occurred. Therefore, one of the following or a plurality of the above is selected and used. (SP5) ... The film transfer means drive motor is driven in the reverse direction by one step. Thereby, the film in which the film over is detected is transported in the reverse direction. (SP6): It is checked whether or not the film has been transported in the reverse direction by a predetermined amount (preset, for example, about 8 cm). (NO) → to (SP5) (YES) → to (end) (end) ... Finish the film transfer processing.

The structure of the film-over detection sensors F and F 'is not limited to the above-described embodiment, but may be a non-contact detection using a reflection type sensor. Also, the number of the film over detection sensors F and F ′ is not limited to the embodiment (two), and for example, a total of three film over detection sensors F and F ′ may be arranged between a pair of front and rear transfer means constituting the film transfer means D, or One piece may be arranged at the center of the pair of front and rear transfer means. Further, in the embodiment, the film over detection sensor F. ON / OFF of F '
Is performed by the movement of the actuator also serving as the film entanglement prevention member 25.
It is needless to say that a prevention member for preventing being caught in the downstream winding portion may be provided independently.

[0029]

According to the first aspect of the present invention, when a film over is detected, the film transport means is immediately driven in the reverse direction, not simply stopped, as in the prior art. Then, the film is transported in the reverse direction and is kept away from the downstream winding portion of the film transport means, so that it is possible to prevent the film from being entangled in the winding portion. For this reason, the operation of removing the over-exposed film can be easily performed. Therefore, the film over detecting means can be arranged near the downstream end portion of the film transport means as in the conventional case, so that there is no need to increase the size of the packaging machine. When the film over is detected, the film transport means is driven in the reverse direction, so that the film with the film over is moved in the direction of the packaging position where the film is removed. For this reason, the work of removing the film described above becomes easier.

According to the second aspect of the present invention, when the film is transported in a state where the film is cut at the center and entangled with the film transporting means, the timing of detecting the film over state by the film over detecting means may be delayed. is there. Even in such a case, by providing the film winding prevention member at the downstream winding portion of the film transport means, the film winding prevention effect becomes more complete.

According to the third aspect of the present invention, since the film is detected by the pair of film over detecting sensors, a part of the film is entangled with one of the film transport means when the film is cut from the center or when the packaging fails. Even in such cases, it is possible to reliably and quickly detect film over. In addition, since the detection sensor also serves as a film entanglement prevention member, the number of parts can be reduced accordingly, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a vertical sectional front view schematically showing a stretch film packaging machine according to the present invention.

FIG. 2 is a longitudinal sectional side view taken along line (X)-(X) of FIG.

FIG. 3 is a cross-sectional plan view taken along the line (Y)-(Y) of FIG.

FIG. 4 is an enlarged plan view showing a mounting portion of a film over detection sensor.

FIG. 5 is a front view of the same.

FIG. 6 is a front view showing a state in which a film over detection hand sensor detects a film over.

FIG. 7 is an explanatory diagram showing an electrical configuration of a control unit of the apparatus.

FIG. 8 is a mechanical time chart of the apparatus.

FIG. 9 is a flowchart illustrating film over detection control.

[Explanation of symbols]

D: Film transport means F, F ': Film over detection sensor 1: Elevator 3: Film roll 25: Film wrap prevention member

Continuation of front page (56) References JP-A-64-23907 (JP, A) JP-A-57-204809 (JP, A) JP-A-7-10116 (JP, A) JP-A-1-240412 (JP) , A) Hikaru Hei 3-110061 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B65B 11/54

Claims (3)

(57) [Claims] 1. A film necessary for packaging is pulled out and transported by a pair of film transporting means arranged so as to sandwich a packaging portion, by sandwiching both side edges in the width direction of a film fed from a film roll. In a stretch film packaging machine that pushes up a product from below with respect to a film stretched over the top and covers the top surface of the product, and folds the end of the film into the bottom of the packaged object, the transfer of the film is downstream from the packaging unit. Detecting means for detecting that the film has been excessively moved, and control means for immediately reversing the film transferring means when the detecting means has detected that the film has been excessively moved downstream from the packaging unit, the excessive film downstream of the packaging unit by reversing the film transport means, the transport to <br/> wrapping position direction to perform film removing work Stretch film packaging machine according to claim Rukoto. 2. The stretch film packaging machine according to claim 1, wherein a film wrap prevention member is provided at a downstream winding portion of said film transport means. 3. The stretch according to claim 1, wherein a pair of said detecting means are provided inside the vicinity of the downstream winding portion of the film transport means, and the detecting means also serves as a film wrap preventing member. Film wrapping machine.