JPS6335922Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a stretch wrapping machine, and more particularly to an improved automatic spiral type stretch wrapping machine.

[Prior art]

Conventionally, an automatic spiral type stretch packaging machine is known that automatically wraps an elastic plastic film, which has adhesive on at least one side, under tension around a packaged item loaded on a pallet and fixes the packaged item. For example, in 1987-
Publication No. 95302 describes a rotary table that automatically stops at a set position after rotating a set number of times, a frame installed on a base frame independently of the rotary table, and a frame set along the frame. In a spiral type stretch packaging machine equipped with a film lifting/lowering frame that rises within a specified stroke range and then falls, and the speed of rising and falling can be set separately, a film is attached to one side of the rotary table, and when the rotary table is stopped, A gripper is provided that closes so as to protrude from the top surface of the rotary table and clamps the film end, and when the rotary table is rotated, opens at a set timing to release the film end without protruding from the top surface of the rotary table. , and is provided on a base frame to face the rotary table, and immediately after the rotary table stops, it swings with a swing radius that allows it to come into contact with the side surface of the object to be packaged, and attaches the film to the object to be packaged. A film presser roller that moves a part of the film to a position where the gripper grips the film; and a film presser roller that oscillates at a swing radius smaller than the lag than the film presser roller and is held between the film presser roller and the gripper by the gripper. A spiral type stretch packaging device characterized by being equipped with a cutter for cutting a stretched film.

is disclosed.

FIG. 1 is a perspective view of the conventional automatic spiral type stretch packaging machine shown in FIG. 5 of the above publication.
In the figure, 1 is the base frame, 2 is the rotating table, and 3
3 is a film roll, 3' is a film, 4 is a film lifting frame, 5 is a column, 7 is a packaged object loaded on a pallet, 8 is a gripper, 9 is a film press roller, 10 is a cutter, and 14 is a brake device. , 15 is a brake roller, 16 is an electromagnetic brake, 17 is a guide roller, 18 is a presser device, 19 is a presser plate lifting arm, 20 is a hoisting device, 21 is a presser plate, 22 is a limit switch, 2
3 is a table conveyor, 24 is a carry-in conveyor, 24' is a guide, and 25 is a carry-out conveyor.

In the conventional automatic spiral type stretch packaging machine shown in FIG. After that, turn table 2
The rotary table is rotated in a state in which a gripper 8 fixed to the gripper 8 grips one end of a film 3' unrolled from a film roll 3 placed on a film lifting frame 4 which moves up and down along a frame 5. As the rotary table 2 starts to rotate, the film lifting frame 4 starts to move up and down, and the lower end of the pallet is placed on the side of the packaged object 7 while keeping the film 3' under tension due to its lifting and lowering movement and the rotational movement of the rotating table 2. Wrap it in a spiral and wrap it. After approximately two rotations of the rotary table 2, the grippers 8 open and release the film ends.

After wrapping, when the gripper 8 comes to the opposite surface of the frame 5, the rotation of the rotary table is stopped, and then the film pressing roller 9 swings to release the adhesive film 3' onto the packaged object 7. is pressed against the side surface of the gripper 8 and guided so that a portion thereof is positioned above the gripper 8.

Then, the gripper 8 closes and grips the film 3' located above it, and the cutter 1
0 swings to cut the film 3' between the gripper 8 and the object to be packaged 7.

In order to prevent the packaged item 7 from shifting during packaging, the top surface of the packaged item 7 is held down by a presser plate 21, and after wrapping, the hoisting device 2
After the presser plate 21 is moved upward by 0, the wrapped items are transferred onto the carry-out conveyor 25.

Further, a brake device 14 is provided to apply tension to the film 3'.

However, in stretch packaging machines with this type of structure, multiple items to be wrapped are piled up on a pallet (plate-like object) and wrapped with a film from the bottom end of the pallet. When the size is normally selected from among the dimensional standards, and since the gripper 8 is fixed to the rotary table 2, the planar dimensions of the packaged items loaded on the pallet are almost the same as the dimensions of the pallet. Apart from this, if the dimensions of both the packaged item and the pallet become smaller, or if the planar dimensions of the packaged item are smaller than the pallet dimensions as shown in Figure 2 a and b, the following problems will occur: It was hot.

In other words, as mentioned above, when both the dimensions of the object to be packaged and the pallet are smaller than the predetermined dimensions, or when the planar dimension of the object to be packaged is smaller than the dimension of the pallet, the distance between the object to be packaged 7 and the gripper 8 becomes larger. Therefore, when the gripper 8 opens at the timing set during rotation of the rotary table 2 and releases the end of the film 3', the end of the film 3' released from the gripper 8 opens as shown in FIG. 2a. After the stretch wrapping is completed, as shown in FIG.
Problems such as the portion getting tangled with the delivery conveyor 25 often occurred.

[Purpose of invention]

The present invention has been made to eliminate the drawbacks of the prior art described above, and its purpose is when the dimensions of the packaged object and the pallet are both smaller than predetermined dimensions, or when the planar dimension of the packaged object is larger than that of the pallet. To provide an automatic spiral type stretch packaging machine capable of preventing the tip of the film from extending like a tail to the outside of the pallet and protruding when the film is smaller than the above-mentioned size.

[Structure of the idea]

To give an overview of the present invention, the present invention relates to a stretch packaging machine, which includes a rotary table that automatically stops at a preset position after rotating a preset number of times, and the rotary table is mounted on a base frame. It is equipped with an independently provided frame and a film lifting frame that moves up and down within a preset stroke range along the frame, and on the rotary table, when the rotary table is stopped, the rotary table A gripper is provided that closes to protrude from the upper surface to clamp the film end, and opens at a preset timing when the rotary table is rotated so as not to protrude from the upper surface of the rotary table to release the film end; and is provided on a base frame to face the rotary table, and immediately after the rotary table stops, it swings with a swing radius that allows it to come into contact with the side surface of the object to be packaged, and attaches the film to the object to be packaged. a film holding roller that moves a part of the film to a position where it is held by the gripper; and a film holding roller that oscillates at a smaller swing radius later than the film holding roller and is held by the gripper between the film holding roller and the gripper. In an automatic spiral-type stretch packaging machine (hereinafter simply referred to as a stretch packaging machine) equipped with a cutter for cutting the wrapped film, the lower end of the film is placed on the object to be wrapped when the film lifting frame is moved before the rotary table is started. The film is placed at a height that is approximately the same height as the upper surface of the pallet, which is located approximately in the center of the rotary table. The rotary table is characterized in that it descends to a position where the lower end is approximately at the same height as the top surface of the rotary table, and then, at a set timing, rises again to the height at which the rotary table was located before the rotation started and stops. .

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto. In addition, for ease of understanding, only essential parts are shown in each drawing.

FIG. 3 is a side view of one embodiment of the stretch wrapping machine of the present invention, and a to e indicate each stage of operation.
In the figure, symbols 1 to 5 (including symbol 3'), 7 to 10,
14 to 23 have the same meaning as in FIG. 1,
Reference numeral 7' denotes a pallet, and 31 is attached to a supporting portion of a holding plate lifting arm 19 that moves up and down along the frame 5, and stops the lifting of the film lifting frame 4 when the upper end of the film 3' reaches the upper end of the object to be packaged 7. A limit switch 32 is mounted on the frame 5 and is located at approximately the same height as the upper end of the pallet 7'; a limit switch 33 is mounted on the frame 5 for stopping the film lifting frame at the starting position; and a limit switch for stopping the lowering of the film lifting frame 4 when the lower end of the film 3' reaches substantially the lower end of the pallet 7';
34 and 35 are kickers, and 36 is a chain.
Although the film press roller 9 and cutter 10 shown in FIG. 1 are not shown for convenience of explanation, they are still necessary components of the stretch wrapping machine of the present invention. In addition, the limit switch 31 is mounted not on the presser plate lifting arm 19 but directly on the frame column 5 so that its position can be adjusted in the vertical direction, so that the holding device 18 and the presser plate lifting arm 19 attached thereto, and the hoisting device 20,
The presser plate 21 and limit switch 22 may be omitted.

As mentioned above, the stretch wrapping machine of the present invention is related to the operation of the film lifting frame 4, and before the film lifting frame 4 starts rotating the rotary table 2, the lower end of the film 3' is approximately at the same level as the upper surface of the pallet 7'. After the rotary table 2 starts rotating, it rises at a set timing, then lowers to a position where the lower end of the film 3' is approximately at the same height as the top surface of the rotary table 2, and then at a set timing. This is different from the stretch wrapping machine shown in FIG. 1 in that the rotary table 2 rises again to the height at which it was located before starting rotation and then stops. In addition, in order to operate the film lifting frame 4 as described above, the stretch wrapping machine of this embodiment is equipped with a commercially available limit switch 32 on the frame 5 that is electrically activated only when the lever is pushed in one direction where the tightener is located. The point is that it is installed at a height that almost corresponds to the top surface of pallet 7'.
Although it is different from the stretch wrapping machine shown in FIG. 1, there are no differences in the components and operations other than those described above, so a detailed description of the structure will be omitted. In addition,
Limit switches 31 and 33 are also necessary for the stretch wrapping machine of FIG. 1, and are naturally provided therein.

Next, the operation of the stretch wrapping machine of this embodiment will be explained step by step.

In the stretch packaging machine of this embodiment, when the article to be packaged 7 is sent to the approximate center of the rotary table 2 by the table conveyor 23, it is moved to the table conveyor 23 by a command from a position detection device such as a beam switch or a limit switch (not shown). is automatically stopped, and then the presser device 18 is automatically lowered, and when the limit switch 22 detects that the presser plate 21 has pressed the top surface of the object to be packaged 7, the presser device 18 is automatically stopped. Their operation is similar to the known stretch wrapping machine shown in FIG. 1, for example.

FIG. 3a shows a state in which the stretch wrapping machine of this embodiment has completed the above operations and before the rotary table 2 starts rotating. At this time, the film lifting frame 4 is stopped at a position where the lower end of the film 3' is approximately at the same height as the upper surface of the pallet 7' on the rotary table 2, and the film lifting frame 4 is stopped at a position where the lower end of the film 3' is at approximately the same height as the upper surface of the pallet 7' on the rotary table 2. 34 holds down the lever of the limit switch 32. Further, the gripper 8 is closed and holds the film 3' with its tip protruding from the upper surface of the rotary table 2.

Next, as in a known stretch wrapping machine, when the rotary table 2 automatically starts rotating, the film lifting frame 4 is driven by a motor (not shown) at a set timing and at a set speed. It is pulled up by the chain 36 and rises along the frame 5. In this way, the process of wrapping the film around the packaged object 7 is started. Further, as shown in FIG. 3b, when the film lifting frame 4 rises and the upper end of the film 3' reaches the upper end of the object to be packaged, the limiter 35 attached to the film lifting frame switches the limit switch 31. By pressing the lever, the film lifting/lowering frame 4 stops, remains in that position while wrapping the film 3' around the upper end of the object 7 by a preset rotation, and then begins to descend. This operation is also similar to known stretch wrapping machines. Incidentally, at a stage after the rotary table has rotated approximately 11/2 times after the start of rotation, the gripper 8 opens and does not protrude from the rotary table, and at the same time opens the end of the film.

FIG. 3c shows a state in which the film lifting frame 4 has been lowered and the cutter 34 has approached the limit switch 32 again. By the way, in the stretch packaging machine of this embodiment, as mentioned above, the limit switch 32 is electrically activated only when the lever is pressed upward by the tightener 34 from below. Even if the lever is pressed down, no electrical signal or command is generated and the film lifting/lowering frame 4 continues to descend.

Next, the film lifting frame 4 is further lowered, and when the lower end of the film 3' approaches the upper surface of the rotary table 2, as shown in FIG. 4 stops, remains in that position while wrapping the film 3' over the lower part of the pallet 7' and the packaged articles 7 by a predetermined rotation, and then begins to rise again.

The film lifting frame 4 rises, as shown in Fig. 3e.
As shown in FIG. 3, when the printer 34 pushes up the lever of the limit switch 32 from below, the film lifting frame 4 stops, and then at a preset timing, the rotating table 2
automatically stops at the position before starting rotation, and the predetermined film winding process is completed.

Thereafter, similarly to the known stretch packaging machine shown in FIG. 1 (see FIG. 1 below), the film presser roller 9 swings to attach the film 3' to the side surface of the packaged item 7 while applying light pressure. , after bringing the film surfaces into close contact with each other and moving a part of it almost above the open gripper 8, the gripper 8 automatically closes and grips the film 3' above it, and then the cutter 10 swings to cut the film 3' between the gripper 8 and the film pressing roller 9. Then cutter 1
0 and the film presser roller 9 swing first in the order of the cutter 10 and then the film presser roller 9, and return to their original positions, and the table conveyor 23 swings before the film presser roller 9 returns to its original position. The entire process is completed by bringing the film cutting part into close contact with each other and carrying out the stretch-wrapped object 7. However, the operations from the time the rotary table stops to the carrying out of the object to be wrapped are performed using the conventional stretch wrapping method. machine (e.g., 1987-
95302 (see Publication No. 95302), detailed explanation will be omitted.

In addition, in the stretch packaging machine of this invention,
In place of the limit switches 31, 32, and 33, a position detection device such as a proximity switch or beam switch, a preset timer, or a preset counter that operates according to the progress of rotation of the rotary table, which is accompanied by an appropriate control circuit, is used. The operation of the film lifting frame may be controlled as described above.

[Effect of idea]

In the stretch wrapping machine of the present invention, the film 3' is not started from the lower end of the pallet 7' as in the known automatic spiral type stretch wrapping machine shown in FIG. Since winding is started from the top surface, when the gripper 8 is opened to release the leading end of the film 3' (Fig. 2, 3''), even if the leading end hangs downward, it will not reach the lower end of the pallet 7'. Since the film 3' is wound on top of the pallet 7', the tip does not extend like a tail to the outside of the pallet 7'.

As detailed above, according to the present invention, when the dimensions of the packaged object and the pallet are smaller than the predetermined dimensions, or when the planar dimensions of the packaged object are smaller than the dimensions of the pallet, the leading end of the film is placed on the outside of the pallet. It is possible to provide a stretch wrapping machine that can prevent the wrapping from stretching out in a tail-like manner.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a conventional stretch packaging machine, Fig. 2 is a schematic diagram showing the state in which an article is wrapped with the conventional stretch packaging machine, and Fig. 3 is a diagram showing the operation of the stretch packaging machine of the present invention. FIG. 1...Base frame, 2...Rotary table,
3...Film roll, 3'...Film, 4...
...Film lifting frame, 5...Structural column, 7...Packaged object, 7'...Pallet, 8...Gripper,
9...Film presser, 10...Cutter, 31,
32, 33... Limit switch, 34, 35...
...Kitsuka, 36...Chain.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A rotary table that automatically stops at a preset position after rotating a preset number of times, a pedestal installed on a base frame independently of the rotary table, and the pedestal. A film lift frame is provided which moves up and down after rising within a preset stroke range along the column, and a film is mounted on the rotary table so that it closes and protrudes from the top surface of the rotary table when the rotary table is stopped. A gripper is provided that grips the end of the film and opens at a preset timing to release the end of the film so as not to protrude from the top surface of the rotary table when the rotary table rotates, and is provided on the base frame and faces the rotary table. Immediately after the rotary table stops, it swings at a swing radius that allows it to come into contact with the side surface of the packaged items placed on the pallet on the table, thereby attaching the film to the packaged items and unwrapping the film. A film press roller that moves the end portion to a position where it is held by the gripper, and a film press roller that oscillates at a smaller swing radius later than the film press roller and is held between the film press roller and the gripper by the gripper. In an automatic spiral-type stretch packaging machine equipped with a cutter for cutting the film, detecting that the film lifting frame has risen and reached a preset upper limit;
a detection device that issues a command signal to shift downward, and a detection device that detects when the film lift frame has descended and reached a lower end of the film approximately at the same height as the top surface of the rotary table, and issues a command signal to shift upward again. An automatic spiral type stretch packaging machine, characterized in that it is provided with a detection device and a detection device that detects when the film lifting frame rises again and the lower end of the film reaches the upper surface of the pallet, and issues a stop command signal. . 2. The automatic spiral type stretch packaging machine according to claim 1, wherein the detection device is a limit switch. 3. The automatic spiral type stretch packaging machine according to claim 1, wherein the detection device is a proximity switch. 4. The automatic spiral type stretch packaging machine according to claim 1, wherein the detection device is a beam switch.