JPH0558991B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a film transfer and stretching mechanism for a stretch film packaging machine.

[Prior art]

A conventional technique of this type is disclosed in Japanese Patent Laid-Open No. 194915/1983. In this technique, endless conveyor belts are arranged one above the other, a film is loaded between the upper and lower belts, and the film is transported as the belts rotate.

[Problem that the invention seeks to solve]

However, in the above-mentioned conventional film transport mechanism, the belts are arranged in two stages (upper and lower) and driven at the same time, so the pulleys that drive the belts must also be arranged in two stages, upper and lower, which not only increases the size of the packaging machine but also increases costs. The disadvantage was that it was also expensive.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a film transporting and stretching mechanism for a packaging machine that has a simple structure, can be downsized, and can be manufactured at low cost.

[Means for Solving the Problems] The present invention for solving the above-mentioned problems involves transporting a film cut to a predetermined length that can wrap the object by a film transport mechanism, and moving it to the packaging position of a packaging machine. In a film transfer tensioning mechanism of a packaging machine, the film is stretched, the object to be packaged is pushed up from below onto the film by an elevator mechanism, and the end of the film is folded into the bottom of the object by a film folding mechanism for packaging. The tensioning mechanism includes a pair of endless flat belts arranged side by side, a contact plate disposed on the upper or lower surface of the flat belt, and a pressing mechanism that presses the flat belt from the lower side or the upper side toward the said contact plate. The flat belt is equipped with a flat belt that allows both sides of the film to be held between the flat belt and the contact plate, and the coefficient of friction of the surface of the contact plate in contact with the film is smaller than the coefficient of friction of the surface of the flat belt in contact with the film. Features.

Further, the present invention is characterized in that means is provided for separating the pressing mechanism from the lower side of the flat belt at a predetermined timing while the film folding mechanism folds the end of the film into the bottom of the object to be packaged.

[Effect]

By configuring the film transport mechanism as described above, the friction coefficient of the surface of the contact plate in contact with the film is configured to be smaller than the friction coefficient of the surface of the flat belt in contact with the film, and the pressing mechanism presses the flat belt against the contact plate, Since both sides of the film are sandwiched between the backing plate and the flat belt, the difference in the coefficient of friction between the backing plate and the flat belt against the film is applied by the pressing mechanism, and the film between the backing plate and the flat belt is pressed. This is the difference in the frictional force against. That is, the frictional force of the flat belt against the film is greater than the frictional force of the contact plate against the film. Therefore, the film is reliably transported by the flat belt.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

1 to 5 are diagrams showing the structure of a film transport mechanism of a packaging device according to the present invention, in which FIG. 1 is a partial plan view, and FIG. 2 is a cross-sectional view taken along the line a-a in FIG. 1. , FIG. 3 is a cross-sectional view taken along line bb in FIG. 1, FIG. 4 is a cross-sectional view taken along line c-c in FIG. 2, and FIG. 5 is a cross-sectional view taken along line dd in FIG. .

The film transport mechanism includes a film supply section 100,
Film transfer section 200 and film cutting section 30
It consists of 0.

The film fed from the film supply section 100 is cut into a predetermined length by the film cut section 300, and both ends of the film are sandwiched between a plate and a flat belt (to be described later) of the film transfer section 200, and the film is moved to a folding position. , that is, the object to be packaged is transported to the position where it is to be packaged.

In the film supply section 100, two support rollers 101 and 102 on which a film roll F is placed are arranged at a predetermined interval, and a driving belt 103 is suspended between the support rollers 101. Tension rollers 104 and 105 are disposed above the support rollers 101 and 102 and are rotatably supported at both ends by a support member 107 for applying a predetermined tension to the film f being fed out from the film roll F. A tension spring 108 is provided at one end of the support member 107, and the tension spring 108 allows the support member 107 to be attached to the central shaft 10.
5 is biased in one direction. In addition, 1
Reference numeral 09 denotes a film end sensor 109 for detecting the end of the film f being fed out from the film roll F.
It is.

The film transfer section 200 includes a timing pulley 20
1, 202, a support plate 204 disposed above the flat belt 203, and three pressers 205, 206, 207 for pushing up the flat belt 203 from below. The two film transfer units 200 are arranged in parallel to form a film transfer unit that pinches and transfers both ends of the film. Since the two film transport sections 200 have substantially the same structure, only one film transport section 200 is illustrated and the others are omitted.

The upper surface of the contact plate 204 is fixed to a push plate 208 to prevent the contact plate 204 from moving upward. One ends of levers 209 and 210 are rotatably attached to both ends of the pressure lever 205 with pins, and the tip of the operating rod of a solenoid 211 is rotatably attached to the other end of the lever 209 with a pin. . The pressure spring 205 also includes a compression spring 218,
219, the flat belt 203 is always connected to the backing plate 204.
By energizing the solenoid 211, the levers 209 and 210 move toward the shaft 20.
9a and 210a in a counterclockwise direction to separate the pressurer 205 from the flat belt 203.

In addition, levers 21 are provided at both ends of the presser 206.
2, 213 is rotatably attached to one end of the lever 212 with a pin, and a solenoid 21 is attached to the other end of the lever 212.
The tip of the operating rod 4 is rotatably attached with a pin, and levers 21 are attached to both ends of the pressurer 207.
One end of the lever 216 is rotatably attached to the lever 215 with a pin, and the solenoid 21 is attached to the other end of the lever 215.
The tip of the operating rod 7 is rotatably attached with a pin. Solenoid 214 and solenoid 21
By energizing 7, the levers 212, 213
and 215, 216 are rotated counterclockwise around pins 212a, 213a and 215a, 216a, and pressers 206, 207 are connected to the flat belt 203.
distance from.

The pressurer 205, solenoid 211, and levers 209 and 210 constitute a right-side pressing mechanism, and the right-side pressing mechanism, flat belt 203, and contact plate 204 constitute a right-side clamp that clamps the right side of the film. The pressure 206, solenoid 2
14. The levers 212 and 213 constitute a central pressing mechanism, and the central pressing mechanism, the flat belt 203, and the contact plate 204 constitute a central clamp that clamps the center of the film. In addition, the pressure 20
7. The solenoid 217 and the levers 215 and 216 constitute a left-side pressing mechanism, and the left-side pressing mechanism, the flat belt 203, and the contact plate 204 constitute a left-side clamp that clamps the left side of the film.

As shown in FIG. 3, the cross-sectional structure of the film transfer section 200 is such that a side plate 224 and a side plate 225 are interposed with spacing bars 226 and 227 (the spacing bar 227 is not shown in FIG. 3, see FIG. 2). Both ends of the shaft 212a of the lever 212 are supported by a side plate 224 and a side plate 225. Also, in the same way, the shaft 213a of the lever 213
Both ends are supported by side plates 224 and 225. A rod plate 208 is attached to the upper part of the side plate 224.
4 with screws. Although not shown, the levers 209, 210 and the lever 21
5,216 also has its shaft 209 similar to the lever 212.
a, 210a and both ends of the shafts 215a, 216a are supported by side plates 224 and 225.

The flat belt 203 is a timing belt having unevenness formed on one side, as shown in a partial longitudinal section in FIG. 7, and is made of ultra-high molecular weight polyethylene resin with reduced frictional resistance. The flat belt 203 consisting of the timing belt is endless and is suspended between the timing pulleys 201 and 202.
The flat belt 203 from the tying pulley 202 is guided in an inclined manner by a guide pulley 228 and a guide pulley 229.

Guide pulley 228 and timing pulley 202
A film hold section FH is arranged between them. The film hold part FH is connected to the hold plate 2.
40, and the hold plate 240 has a lever 2.
One end of 37 is rotatably attached by a pin 236. At the other end of the lever 237, the tip of the operating rod of the centering solenoid 235 is connected to the pin 23.
It is installed with 6.

On the top surface of the flat belt 203 are side plates 224 and 225.
A pressurizer 230 with a width that spans the width is assigned. This pressurer 230 is fixed to the bottom surface of a pusher plate 231 having a substantially U-shaped cross section with both sides of the plate partially bent upward. Press. Note that the compression spring 232 has a shape similar to that of the push plate 208.
covered with the edges. The holding plate 240 disposed below the flat belt 203 has a U-shaped cross section with both sides bent upward, and the upper end of the holding plate 240 is bent outward to form a pressing surface facing parallel to the presser 230. It was formed. Note that the distance between both walls is such that the flat belt 203 can be attached therebetween. Further, the contact plate 233 disposed on the lower surface of the flat belt has a U-shaped notch formed in both sides of the flat resin material so that both walls of the hold plate 240 engage with each other. It is installed between walls, and the protrusions on both sides are fixed to the side plates 224 and 225 so as to be in contact with the lower surface of the flat belt 203. Therefore, the holding plate 240 operates using the notches on both sides of the contact plate 233 as guides.

When the centering solenoid 235 is energized, the lever 237 rotates clockwise about the fulcrum shaft 239, and the hold plate 240 is raised by the pin 238 along the notch of the contact plate 233, and the pressure plate 23
0 is pushed against the elasticity of the compression spring 232 to separate it from the upper surface of the flat belt 203.

At the end of the shaft 202a of the timing pulley 202, the rotational force of the shaft 202a is applied to the support roller 101 in a timely manner.
A pulley 110 is rotatably connected to a film feed pulley 111 (described later) via a belt 103. This pulley 110 is held between two clutches 241a and 241b.
This clutch plate 241a is connected to the shaft 202a by a key provided near the end of the shaft 202a and engaged in a key groove.
It is locked in the rotational direction of the shaft 202a and is slidably mounted in the axial direction of the shaft 202a. clutch plate 241
b is fixed to the end surface of the shaft 202a with a screw to prevent the pulley 110 and the clutch plate 241a from coming off.
The clutch plate 241a is biased by a compression coil spring 242 attached to the shaft 202a in advance.
The pulley 110 is pressed together with the clutch plate 241b. Therefore, when a torque exceeding a predetermined value is applied to the pulley 110, the pulley 110 and the clutch plates 241a and 241a
41b, and the rotational force of the shaft 202a is no longer transmitted to the pulley 110.

The belt 103 of the film supply section 100 is
It is suspended between the support roller 101, the pulley 110, and the film feed pulley 111, and rotational force is transmitted by the timing pulley 202 via the shaft 202a.

A film over detection section 260 is disposed at the rear end of the film transfer section 200. The film over detection section 260 includes an L-shaped film detection lever 263 that rotates around a shaft 261, and a detector 26 that detects the deviation of one end of the film detection lever 263.
It is equipped with 2. In the film over detection section 260 configured as described above, if wrapping fails or the film is transferred to the rear end without being wrapped, the film comes into contact with the film sensing lever 263, and the film sensing lever 263 moves the shaft 261. By detecting the displacement of the end of the film sensing lever 263 by the detector 262, it is detected that the film has been transferred to the rear end. Detector 26
2 detects the transfer of the film, the rotation of the film transfer section 200 is stopped, and the film is removed by hand or the like.

The film cutting section 300 includes a cutter 301, a solenoid 302 for driving the cutter 301, and a cutter receiver 303. Katsuta receiver 30
3 is rotatably attached to a bracket 306 fixed to the packaging machine frame 10 by a support shaft 304.
Further, the cutter receiver 303 is biased in one direction by a coil spring 306. By rotating the cutter receiver 303 counterclockwise around the support shaft 304, it can be opened to facilitate loading of the film f, as shown by the dashed line.

In the film transfer mechanism having the above structure, when setting a film, the cutter receiver 303 is first rotated counterclockwise about the support shaft 304 to open the cutter receiver 303 as shown by the dashed line in FIG. Next, the film f fed out from the film roll F is moved between tension rollers 104 and 10 as shown in FIG.
5, and further through the upper surface of the film feed pulley 111 to the presser 230 and the flat belt 203.
and push it into the front edge. Next, when the cutter receiver 303 is set in the normal position and the feed key (not shown) on the operation unit is pressed, the motor operates as described later, and the rotation of the drive pulley 250 causes the timing pulley 2
The flat belt 203 rotates via the belts 01 and 202. When the film f has been transported a predetermined length by the rotation of the flat belt 203, the motor is stopped to stop transporting the film, and the solenoid 302
The cutter 301 is operated to form discontinuous cuts on the surface of the film f. Then, the motor operates again, and the flat belt 20 consisting of the timing belt
3, the film f is transferred.

When the film f is transferred for a predetermined length (the discontinuous cuts are formed on the hold plate 24 of the film holding section)
0), film feed pulley 1
11 to stop the rotation of the film feed pulley 111,
By operating the centering solenoid 235, the film f is pressed 2 by the hold plate 240.
30 to separate the film from the surface of the flat belt 203. Therefore, at this time, even though the belt 103 has stopped rotating, the flat belt 203, which is a timing belt, is rotating due to the action of the clutch plate 241.

The leading end of the discontinuous cut in the film is transferred, and the film is cut from the discontinuous cut. After the cut film is transported to a predetermined position for centering, the motor is stopped.

The operating solenoids 211, 214, 217 of the pressers 205, 206, 207 operate in accordance with the operating timing of each film folding plate,
The film held between the contact plate 204 and the flat belt 203 is released.

Note that 251 and 252 are adjustment screws for adjusting the distance between the two parallel film transfer units 200 according to the width of the film, and 253 and 254 are gears that mesh with the adjustment screws. be. By rotating a handle (not shown) attached to one end of the support rod 255, the distance between the film transfer sections 200 arranged in parallel can be adjusted.

FIG. 9 is a diagram showing a packaging machine in which the film transport mechanism having the above structure is installed. As shown in the figure, a film transfer section 200 configured as described above is shown.
are arranged at predetermined positions of the packaging machine, and left and right folding members 501, 502 and folding members 50 are placed above the pressurers 205, 206, 207.
3. A film folding section 500 consisting of a discharge pusher 504 and the like is located at the bottom, and a film to be packaged carried in from a carry-in section (not shown) is transported between the flat belt 203 of the film transport section 200 and the contact plate 204. An elevator mechanism 400 is arranged to push up the film from below, which is held and stretched on both sides. By starting the elevator mechanism driving motor 402, the torque is transferred to the reducer 403 and the cam 40.
4, transmitted to the elevator mechanism 400 via the lever 405 and the connecting rod 406, and the elevator head 4
01 is configured to move up and down. Note that 407 in the figure is a timing disk connected to the rotating shaft of the reducer 403 in order to time each operation. Further, 600 is a label printer, and the label printer 600 includes a display section 601 and an operation section 6.
02, a label issuing port 603, etc.

The specific configuration and operation of the packaging machine are described in the packaging device (Japanese Patent Application No. 77113/1986) previously filed by the present applicant.
The details are omitted here as they are disclosed in detail in the previous issue.

FIG. 10 is a mechanical chart showing an example of the operation of each part of the packaging machine. In the figure, the horizontal axis indicates each degree of rotation (°) of the timing disk 407.

The packaging machine described above is configured to complete packaging in two packaging cycles for one packaging machine. That is, when focusing on a certain packaged item, the light weight stability signal or detection signal of this packaged item is used to carry the packaged item onto the elevator head, cut the film, transfer the cut film, and stretch it to a predetermined position. Then, in response to a measurement stability signal or a detection signal for the next packaged product, the packaged product is raised on the elevator head of the elevator mechanism 400, and a wrapping operation is performed in which the film covering the packaged product is folded into the bottom of the packaged product. It's summery.

The film cut length is divided into 1 to 7 levels.
Depending on the cut length of the film, the flat belt 20
3, the start and stop timing of the cutter 301, and the start and stop timing of the centering solenoid and centering brake.

When a packaged item is placed in the loading section (not shown) of the packaging machine, a weighing stability signal or a packaged item detection signal is generated, and the elevator mechanism driving motor 402 is activated.
is activated (timing disk angle 0°). The carry-in conveyor starts at a predetermined timing (timing disc angle 20°). Furthermore, the electric heater mechanism 400 starts rising at a timing disc angle of 5°, reaches the upper limit at a timing disc angle of 65°, and reaches its upper limit at a timing disc angle of 65°.
It starts descending at 115° and reaches the lower limit at a timing disc angle of 175°. The flat belt 203 is a timing disk angle
Rotation starts at 180°, and the timing disc angle is set according to the cut length of the film (the numbers are 1 to 7).
(showing the film cut length divided into stages),
Stop, start and stop. The cutter 301 is also operated at a predetermined timing disc angle depending on the length of the film to be cut. Also, centering solenoid 2
The operation stop timing of 35 is also performed at a predetermined timing disc angle depending on the cut length of the film. In addition, the centering brake that stops the rotation of the film feed pulley 111 has a timing disc angle.
It is turned off at 17 degrees and stopped at a predetermined timing disc angle depending on the length of the film cut.

The left and right folding members 501, 502 and the rear folding member 503, which perform left and right rear folding of the film, start forward movement at a timing disc angle of 60°, stop at a timing disc angle of 140°, and move backward at a timing disc angle of 260°. and stop when the timing disc angle is 340°. The discharge pusher 504 is a timing disk angle
Starts forward movement at a timing disc angle of 140°, stops at a timing disc angle of 220°, starts backward movement at a timing disc angle of 260°, and stops at a timing disc angle of 340°. The front left and right clamps operate at a predetermined timing disc angle set based on the type of item to be packaged, and stop at a timing disc angle of 200°. The rear left and right clamps operate at a predetermined timing disc angle set based on the type of item to be packaged, and stop at a timing disc angle of 140°. The front center clamp operates when the timing disc angle is 140° and stops when the timing disc angle is 200°. Further, the rear center clamp operates at a predetermined timing disc angle depending on the film count length, and stops at a timing disc angle of 140°.

The above angular movement is performed based on packaging condition data for each item to be packaged, which is transmitted from the control section of the label printer 600 to the control section of the packaging machine.

In the above embodiment, a timing belt made of a polyurethane material having frictional resistance is used as the flat belt 203, which improves the conveyance of the film and allows the film to be folded into the flat belt 203.
Although the flat belt 203 is made easy to come out from between the belt and the contact plate 204, it is obvious that the flat belt 203 is not limited to a timing belt and may be a simple flat belt.

In addition, the contact plate 204 is made of ultra-high molecular weight polyethylene containing a conductive material to prevent static electricity from being generated.
The coefficient of friction is smaller than that of the surface.

In the embodiment, the uneven toothed surface of the timing belt of the flat belt 203 was placed on the inside, and the film was transferred using the flat portion. By doing so, the film can be fed even more reliably. In this case, it is obvious that the timing pulleys 201 and 202 are not toothed pulleys.

Furthermore, if a toothed belt is used on both sides, belt feeding and film feeding will be ensured.

In the embodiment, pressurers 205, 206, 207
Two pairs of levers 209, 210, 21 at each end of the
1, 213, 215, and 216, but if the pressure is connected to the plunger of the solenoid by a pair of levers at the center of the pressure, the pressure can be freely rotated in the longitudinal direction around the pin of the lever. Make sure that the entire top surface of the plate 203
press against. In other words, in the configuration in which the levers are provided on both sides of the embodiment, if the dimensional accuracy of the hole pitch of the lever etc. is not accurate, the contact will be uneven against the contact plate.
In the above configuration, the entire upper surface of the presser is securely pressed against the contact plate 203. Therefore, the film can be reliably held during folding, resulting in a good packaging finish. Further, since the machining accuracy of parts is not required to be so high, costs can be reduced.

Furthermore, by making the diameter of the film feed roller 111' smaller than the diameter of the timing pulley 202, pre-stretching in the film transport direction is possible. Further, by widening the distance between the pair of film transport mechanisms at the leading ends, pre-stretching in the film width direction is possible. Therefore, compared to the conventional film transport mechanism using a belt, pre-stretching can be performed and the finish of the packaging is improved.

Further, the same effect can be obtained by arranging rollers on the side of the contact plate 206 so that the width direction of the belt 203 is the axial direction.

〔Effect of the invention〕

As explained above, according to the present invention, the film transport mechanism is constituted by one endless flat belt, a contact plate, and a pressing mechanism, so that the structure of the film transport mechanism is simple and its height can be reduced. , the excellent effects of miniaturization and cost reduction can be obtained.

In addition, since the pressing mechanism is configured to press the flat belt toward the contact plate, the difference in the frictional force between the contact plate and the flat belt against the film causes the film cut to a preset length to slip by the flat belt to the wrapping position. This provides the excellent effect of being able to be transported without any problems.

In addition, since the film is transferred by clamping the film with a constant pressure, the film does not come off the flat belt even if pre-stretching is applied in the film transport direction and width direction. Compared to the conventional film transport mechanism, pre-stretching can be performed, resulting in a better packaging finish.

[Brief explanation of the drawing]

1 to 5 are diagrams showing the structure of a film transport mechanism of a packaging device according to the present invention, in which FIG. 1 is a partial plan view, and FIG. 2 is a cross-sectional view taken along the line a-a in FIG. 1. , FIG. 3 is a cross-sectional view taken along line bb in FIG. 1, FIG. 4 is a cross-sectional view taken along line c-c in FIG. 2, and FIG. 5 is a cross-sectional view taken along line dd in FIG. 6 is a cross-sectional view of the pulley 110, and FIG. 7 is a cross-sectional view of the flat belt 2.
03, FIG. 8 is a diagram showing the film set state, FIG. 9 is a diagram showing the configuration of a packaging machine equipped with a film transport mechanism according to the present invention, and FIG. 10 is a diagram showing each part of the packaging machine. This is a mechanical chart showing an example of operation. In the figure, 100... film supply section, 2
00...Film transfer section, 300...Film cutting section.

Claims (1)

[Scope of Claims] 1. A film cut to a predetermined length that can be used to wrap an object is transferred by a film transfer mechanism, stretched to a wrapping position of a packaging machine, and the object to be packaged is lowered onto the film by an elevator mechanism. In a film transporting and tensioning mechanism of a packaging machine that pushes up from the side and folds the end of the film into the bottom of the packaged object using a film folding mechanism for packaging, the film transport and tensioning mechanism includes a pair of endless flat sheets arranged in parallel. A belt, a contact plate disposed on the upper surface or the lower surface of the flat belt, and a pressing mechanism for pressing the flat belt toward the contact plate from the lower side or the upper side, and a film is provided between the flat belt and the contact plate. A film transfer and tensioning mechanism for a packaging machine, characterized in that both ends of the film can be clamped, and the coefficient of friction of the surface of the plate in contact with the film is smaller than the coefficient of friction of the surface of the flat belt in contact with the film. 2. Claim 1, characterized in that the film folding mechanism is provided with means for separating the pressing mechanism from the lower side of the flat belt at a predetermined timing while the film folding mechanism folds the end of the film into the bottom of the packaged object. Film transfer and tension mechanism of packaging machine. 3. The film transporting and tensioning mechanism of a packaging machine according to claim 1, wherein the pressing mechanism is divided into right, left and center parts. 4. The pressing mechanism includes a pressing plate that presses the flat belt from below or above, and a rotatable lever having one end of the pressing plate pivotally supported, and a solenoid that rotates the lever in a predetermined direction. A film transporting and tensioning mechanism for a packaging machine according to claim 1, comprising: