JP2569701Y2 - Tensile expansion mechanism - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention is directed to a thin film which is gripped at both ends by a pair of chucks, and the chuck is moved by a chain to move the bag. The structure of the expansion mechanism that allows the expansion of the expansion mechanism.

[0002]

2. Description of the Related Art For example, Japanese Unexamined Utility Model Publication No. Hei 2-26066 discloses an automatic apparatus in which a bag made of polyethylene or the like is mounted inside an empty box for storing articles. This automatic device is provided with an opening mechanism for adsorbing suction pads on both sides of a bag whose both ends are gripped and opening the mouth of the bag.

That is, as shown in FIG. 2, a film 3 wound from a film roll 1 by rotation of a motor (not shown) is returned to a roller 5 and then returned once to a tension bar 7 to be applied to a next roller 9. Through the first chuck 11 working one pair at both ends near the tip is gripped,
First chain 1 provided with first chuck 11
It moves with the movement of 3. Film 3 is a stack of two
It is cylindrical when opened. The moved film 3 is sealed by welding by the seal / cutting device 15 and cut at the same time to form one bag 17. The front end of the bag 17 is suctioned from both surfaces by a pair of suction pads 19 while being held by the first chuck 11, and is expanded. The second chuck 21 in which two pairs work in a pair in an expanded state.
The four corners of the edge of the mouth widened are gripped. The bag 17 is put on the box 25 by moving with the movement of the second chain 23 provided with the second chuck 21. Thereafter, air is blown into the box 25 from above the bag 17 by the air blower device 27, whereby the bag 17 is turned over and mounted on the inner surface of the box 25. The expansion mechanism provided with the suction pad 19 has, for example, the structure shown in FIG. FIG. 3 corresponds to an enlarged horizontal cross-sectional view of the central portion of FIG. Note that, in contrast to FIG. 2 which is the prior art described in the gazette, FIGS.

That is, the first chuck 11 and the second chuck 21 are moved by the movement of the first chain 13 or the second chain 23, respectively. First chain 1
3 and the second chain 23 are sprockets 2 respectively.
A predetermined trajectory is drawn guided by 9, 31. Each chain 13, 23 is guided by guide rails 33, 35. When the bag 17 by the first chuck 11 is stopped at a predetermined position down from top to bottom in the center of the mobile device (Figure 2), each suction pad 19 is advanced by the suction pad cylinder 37, on one side of the bag 17 A total of four pairs of suction pads 19 are suctioned on one pair and on both surfaces. Then, each suction pad 19 retreats in the opposite direction on both sides, and the mouth of the bag 17 is widened. At this time, the second chuck 21 is already located below. Two pairs of the second chucks 21 are provided so as to grip four corners of the opened mouth. The second chuck 21 is connected on one side of the bag 17 by a chuck connecting plate 39. The expanded bag 17
Extend along the inner surface of the chuck connecting plate 39. Therefore, the opened mouth of the bag 17 is guided to the second chuck 21 along the chuck connecting plate 39, and the gripping is performed accurately. As soon as the gripping by the second chuck 21 is performed, the gripping of the first chuck 11 is released. Release of the gripping and gripping, the chucks each lever 41 is advanced by lever cylinder 43 11,2
This is done by touching the number 1.

A of the first chain 13 in FIG.
A front view from the direction is shown in FIG. FIG. 5 is a side view seen from the direction B in FIG. At the position where the suction is performed by the suction pad 19, the first chain 13 is partially guided by the guide rail 33. At the lower end of the guide rail 33, the direction of the first chain 13 is directed to the outside of the apparatus. Sprocket 29 is provided. The sprocket 29 is rotatable around a rotation shaft 47 fixed to a frame 45 via a bearing 49.

[0006]

However, in the above-described conventional opening mechanism, it is desired that the suction pad 19 sucks the bag 17 efficiently. That is, if the negative pressure of the air for performing the suction is small, the suction is not sufficient, and if it is severe, the suction may not be performed. On the other hand, if the negative pressure is too high, the bag is rapidly adsorbed to only one of the suction pads, which causes the bag to wrinkle, resulting in incomplete suction. Therefore, the suction is performed by the appropriately adjusted negative pressure. However, the first chuck 1
If the bag 17 with both ends removed by 1 is wrinkled for some reason, the suction by the negative pressure adjusted to the fixed size may be incomplete. Efficient adsorption is also necessary to improve the speed of operation of the apparatus.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to provide a tension-spreading mechanism capable of efficiently sucking a suction pad for expanding a bag edge.

[0008]

In order to achieve the above-mentioned object, a tension-spreading mechanism according to the present invention is characterized in that a bag made of a thin film is folded and held at both ends by a pair of chucks. In the opening mechanism in which the bag moves by being moved by a pair of chains and the mouth is expanded by being sucked by suction pads from both sides, a sprocket provided at a position where suction is performed by suction pads and guiding the chain is provided. A rotation shaft is supported so as to be slidable in the axial direction, and a distance between the pair of chains is made variable by slide driving means.

[0009]

The chain bag is held in a folded state at both ends by a pair of chucks. The chuck is moved by the movement of the pair of chains. Thereby, the bag is moved. When the bag comes to a predetermined position where it is sucked by the suction pad, the sprocket for guiding the chain slides in the axial direction by the slide driving means. This slide increases the distance between the chains guided by the sprocket. As the distance between the chains increases, the bag is pulled with the pins in the width direction. Thereafter, the suction pads are sucked on both sides of the bag.

[0010]

Next, an embodiment of the present invention will be described with reference to FIG. The automatic device provided with the tension expanding mechanism of the present embodiment is substantially the same as the conventional example (FIGS. 2 and 3). The front view of the position of the first chain 13 where the suction is performed by the suction pad 19 is substantially the same as that of the conventional example shown in FIG. FIG. 1 of the present embodiment is an enlarged view corresponding to FIG. 5 of the conventional example.
It is formed symmetrically on the left and right.

That is, the frame 45 has a drymet bush 5 on the outer periphery of an idle shaft 51 slidable in the axial direction.
3, a sprocket 29 is provided. An air cylinder 57 is coaxially attached to the tip of the idle shaft 51 via a push ring 55 so that the idle shaft 51 can slide toward the frame 45, that is, outward. The air cylinder 57 is fixed to a bracket 59 fixed to the frame 45. Also frame 4
5 is provided with a spring plunger 61,
The tip protrudes from a hole 63 opened in the frame 45, and urges the sprocket 29 inward, that is, the return direction, via a cap 65 for a thrust bearing and a sliding plate 67.

A slide drive means 69 having the above-described air cylinder 57 and spring plunger 61 is provided on both of the pair of first chains 13. Hereinafter, the operation of the present invention will be described. When the first chuck 11 gripping both ends of the bag is lowered by the first chain 13 from above along the guide rail 33 and the bag 17 is located at a predetermined position where the bag 17 is sucked by the suction pad 19, the first Of the chain 13 is temporarily stopped. Then, the air cylinder 57 operates to slide the idle shaft 51 outward. As a result, the sprocket 29 also moves outward against the urging force of the spring plunger 61. The stop and the movement of the sprocket 29 are performed almost simultaneously, and even if the sprocket 29 whose rotation is not stopped is pressed by the spring plunger 61, no trouble occurs due to the operation of the sliding plate 67 and the like. By moving the sprocket 29 outward in this manner, the distance between the pair of chains 13 is increased, and accordingly, the distance between the pair of first chucks 11 is also increased. Thereby, the first chuck 11
The bag 17 that has been gripped is pulled by the pin. When the bag 17 made of the thin film 3 is stretched as described above, the suction pad 19 that performs suction from both sides of the bag 17 can be easily sucked,
Adsorption efficiency can be increased. That is, there is little variation such as wrinkling or less wrinkling on the surface of the bag 17, the negative pressure for performing suction can be set to an appropriate constant value, and failure or incomplete suction can be prevented.
The mouth of 7 can be expanded without failure. In addition, since the bag 17 is pulled with the pins, the suction pad 19
There is no variation in the chucking position of the second chuck 21. Therefore, there is no variation in the gripping position of the second chuck 21 to be gripped next. Therefore, the mouth of the bag 17 can be expanded into a correct square.
In addition, by increasing the adsorption efficiency, the operation of the entire automatic machine can be quickly performed.

In the above embodiment, the slide moving means 69 for moving the sprocket 29 is provided on both sides of the pair of chains 13, but in other embodiments, it is provided on one side. It is also possible. Also, the slide moving means 69 is not necessarily the air cylinder 5
However, the present invention is not limited to the method of FIG. 7 and other driving means may be used.

[0014]

As is apparent from the above description, in the tension-spreading mechanism according to the present invention, the sprocket is slid by the slide driving means to increase the distance between the pair of chains, so that the pair of chains moved by the chains is increased. Since the bag whose both ends are gripped by the chuck can be pulled by the pins, the suction efficiency of the suction pad that suctions on the pulled surface can be improved.

[Brief description of the drawings]

FIG. 1 is a side view of a main part of a tension expanding mechanism according to an embodiment of the present invention.

FIG. 2 is a schematic side view of an entire automatic machine having a conventional expanding mechanism.

FIG. 3 is an enlarged horizontal sectional view of the expanding mechanism of FIG. 2;

FIG. 4 is a partial front view seen from a direction A in FIG. 3;

FIG. 5 is a partial side view as viewed from a direction B in FIG. 4;

[Explanation of symbols]

1 roll 3 film 7 tension bar 11 for the first chuck 13 first chain 15 sealing cutting device 17 bags 19 suction pad 21 and the second chuck 25 boxes 27 air blower device 29, 31 sprockets 33, 35 guide rail 37 suction pads cylinder 41 the lever 43 lever cylinder 47 rotating shaft 49 bearing 51 idle shaft (rotary shaft) 55 push the ring 57 air cylinder (slide driving means) 61 spring plunger 67 sliding plate

Claims (1)

(57) [Scope of request for utility model registration] 1. A bag made of a thin film is held in a folded state at both ends by a pair of chucks, and the chuck is moved by a pair of chains to move the bag and to be sucked by suction pads from both sides. In the opening mechanism in which the mouth is expanded, a sprocket that is provided at a position where suction is performed by a suction pad and guides the chain has a rotation shaft that is supported so as to be slidable in the axial direction. A tension-spreading mechanism characterized in that the distance is variable.