JPH06102448B2 - Bag opening device in bag packing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial field of application" The present invention relates to a bag opening device mainly provided in a packing machine for packing vegetables and the like, and is particularly applicable to opening a bag made of a stretched film. A bag opening device.

"Prior art" When packing vegetables, etc., as a device for opening the bag, conventionally, for example, both ends of the mouth of the bag are clamped together by clamps on the front and back sides, and these clamps are moved in a direction that narrows the gap. Therefore, a device for opening the bag is known.

[Problems to be Solved by the Invention] By the way, in such a device, since both ends of the mouth of the bag sandwiched between the front and back sides by the clamp cannot be opened, the opening ratio of the bag is poor and There is an inconvenience that the filling of vegetables in the bag is often impaired in the process.

In addition, the bag used in such a device needs to have a sufficient straining strength so that it can be opened by simply narrowing both ends of the mouth. Therefore, the bag is usually a composite film having a thickness of about 50 to 80 μm. However, since such a composite film is expensive, there is a demand to use an inexpensive stretched film bag having a thickness of about 20 to 25 μm. However, in the above-mentioned apparatus, the stretched film bag has a weakness and a sufficient opening cannot be obtained, so that the stretched film bag cannot be used.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a bag opening device that can be applied to a bag made of a stretched film and that can surely and sufficiently open the bag. It is in.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention provides a support member that rotates up and down about a central axis, and the support member so that a horizontal interval between the support members can be adjusted. A pair of sliding members provided,
A rod receiving member provided on each sliding member so as to be horizontally movable in the direction in which the sliding members are arranged, and each rod receiving member is rotated in the circumferential direction with its axial direction orthogonal to the moving direction of the rod receiving member. A freely provided rod, a locking claw provided at the tip of each rod so as to project in the radial direction of the rod, and a rotation claw for rotating the rods in the circumferential direction to change the direction of the locking claw. The distance between the moving mechanism portion and the pair of locking claws inserted into the mouth of the bag is widened by moving the rod receiving member with respect to the sliding member to lock the bag with the pair of locking claws. Locking spring and each rod receiving member are horizontally moved against the sliding member against the elastic force of the locking spring to narrow the gap between the pair of rods and lock the bag with the pair of locking claws. And a sliding mechanism of the pair of rod receiving members. A pair of frame body provided horizontally freely relative movement perpendicular to the moving direction with respect to members,
It is provided in each frame side by side in their relative movement direction,
A pair of inner clamp pieces to be inserted into the center of the mouth of the bag hanging on the locking claw with the mouth upward by pivoting the supporting member upward about the central axis, and each inner clamp piece. The outer clamp pieces that are rotatably attached to the outside of the bag and the clamping ends of each outer clamp piece are rotated toward the inner clamp pieces to clamp the bag mouth in cooperation with the inner clamp pieces. And a sandwiching means for moving the one frame body with respect to the other frame body to open the bag for moving one inner clamp piece together with the outer clamp piece in the arrangement direction of the inner clamp piece. The opening means and the opening mechanism for rotating the respective outer clamp pieces with respect to the inner clamp pieces to release the sandwiching of the bag are provided.

[Action] Insert the pair of locking claws into the mouth and separate the front and back of the bag mouth locked by the locking claws by the action of the locking spring with each pair of inner clamp piece and outer clamp piece. The bag is opened again by re-sandwiching and moving the clamp pieces apart. Therefore, even a bag made of a stretched film having a weak strain can be opened as large as possible and accurately regardless of the strength of the strain.

[Examples] Hereinafter, the opening device of the present invention will be described in detail by examples.

1 to 5 are views showing an embodiment of the present invention. In FIG. 1, reference numeral 1 is a central shaft, and a rotating member 2 that is rotated about the central shaft 1 by a drive device (not shown) is provided on the central shaft 1. A pair of supporting rods 3, 3 are attached to the moving end side of the rotating member 2, and a sliding mechanism portion 4 is provided on the tip end side of the supporting rods 3, 3. The rotating member 2 rotates up and down. The support rods (support members) 3 are parallel to each other in a plane parallel to the horizontal central axis 1, and their axial directions are orthogonal to the central axis 1 in the vertical view of the plane.

The sliding mechanism section 4 includes a bearing member 5 which is orthogonal to the support rods 3 and 3 and is horizontally screwed to the tips of the support rods 3 and 3.
As shown in FIG. 2, mounting plates 6 and 6 screwed to both ends of the bearing member 5, sliding screws 7 inserted between the mounting plates 6 and 6, and screwed to the sliding screws 7. It is composed of a pair of sliding members 8, 8 attached as described above. The sliding screw 7 is one in which one side is cut into a regular screw and the other side is a reverse screw so that both sides of the intermediate part are symmetrical, and the screw member 8 is screwed to the forward screw side and the reverse screw side, respectively. , These are attached equidistantly from the middle part. The sliding member 8 is composed of a pair of sliding bodies 9 and 9A facing each other as shown on the right side in FIG. 2 and a pair of shafts 10 and 10 which are provided in parallel by inserting between the sliding bodies 9 and 9A. The sliding bodies 9, 9 are arranged such that the end surfaces 9a, 9a on the side where the sliding bodies 9, 9 are screwed into the sliding screws 7 are in contact with the surface of the bearing member 5. Under such a structure, the sliding members 8 and 8 are slidable on the bearing member 5 in the axial direction of the sliding screw 7 by the rotation of the sliding screw 7, respectively. There is. Sliding screw 7 and shaft
Reference numeral 10 is parallel to the horizontal bearing member 5.

A rod receiving member 11 is slidably attached to the shafts 10 and 10 between the shafts 10 and 10, respectively. Rods 12, 12 are rotatably inserted in the rod receiving portions 11, 11 respectively in rod receiving portions 11a located between the shafts 10, 10 in a direction orthogonal to the shaft 10. A return spring (locking spring) 13 is arranged between the sliding member 9A on the inner side and the rod receiving portion 11a of the rod receiving member 11 on the sliding members 8 and 8 to prevent the sliding member 9 on the outer side from sliding. A pressing mechanism section 14 is provided on the outer surface. The pressing mechanism part 14 penetrates the sliding body 9 and contacts the rod receiving part 11a, and presses the rod receiving member 11 against the elastic force of the return spring 13.
15 and an air cylinder 16 for advancing and retracting the pressing rod 15. Based on such a configuration, the rod receiving member 11 has an inner sliding member when pressed by the pressing mechanism portion 14.
It is moved to the 9A side, and when the pressing is released, it is returned to the initial position on the outer sliding body 9 side by the elastic force (restoring force) of the return spring 13.

The rod 12 provided on the rod receiving member 11 is provided at its rear end with a rotating mechanism 17 for rotating the rod 12 as shown on the left side in FIG. The rotating mechanism 17 includes a pinion 18 fitted to the rod 12, a round rack 19 that meshes with the pinion 18, and an air cylinder 20 that moves the round rack 19 forward and backward.
The rod consists of a rod driven by the air cylinder 20.
It rotates 12 for a certain distance and returns it to its original position.

Further, locking claws 21, 21 are provided at the tips of the rods 12, 12 so as to extend in a direction orthogonal to the rod 12, as shown in FIG. These locking claws 21, 21 are inserted into the mouth portion of the bag that has been previously opened as described later, and both ends of the mouth portion are pulled outward from the inside to hold the bag in the opened state. .

In this device having such a structure, the rod 12, 12 and the locking claws 21, 21 are shown by the two-dot chain line in FIG. 1 by rotating the rotating member 2 about the central axis 1. It will be pulled up from the position to the position shown by the solid line. A pair of clamps 22, 22 are arranged near the positions of the locking claws 21, 21 of the rods 12, 12 shown by solid lines.

One clamp 22 is attached to the fixed frame 28 of the fixed frame body 24, and the other clamp 22 is attached to the movable frame 29 of the movable frame body 25. The fixed frame body 24 is provided rotatably up and down on a base shaft 23 parallel to the central axis 1, and a movable frame body 25.
Is the shaft 10 in the horizontal state (moving direction of the rod receiver 11)
It is provided so as to be movable with respect to the fixed frame body 24 in the horizontal direction orthogonal to. The pair of clamps 22, 22 are arranged side by side in the moving direction of the movable frame body 25 with respect to the fixed frame body 24. The clamp 22 is composed of an inner clamp piece 26 and an outer clamp piece 27. As shown in FIG. 3, each of the inner clamp pieces 26, 26 is a thin plate whose lower end is sharpened like a blade, and when the abutting contact each other, the lower end is made sharp. Since the inner clamp pieces 26, 26 are thin plate-like and the lower ends thereof are sharp, the inner clamp pieces 26, 26 are easily inserted into the center of the mouth of the bag held in the opened state by the locking claws 21, 21. Will be done.

As shown in FIG. 4, the outer clamp pieces 27, 27 have a plan view T.
It is in the shape of a letter, and is rotatably supported by shafts 31 and 31 on mounting members 30 and 30 provided in pairs on the fixed frame 28 and the movable frame 29, respectively. These outer clamp pieces 27,2
7 is the inner clamp pieces 26, 26 as shown in FIG.
The end on the side is the sandwiching ends 32, 32, and the end on the opposite side is the movable ends 33, 33. Flange-shaped elastic bodies 34, 34 made of rubber, soft synthetic resin, or the like are attached to the clamping ends 32, 32, and the outer clamp pieces 27, 27 clamp the bag with these elastic bodies 34, 34. It is arranged so as to contact the outer surfaces of the inner clamp pieces 26, 26 when in the state. As shown in FIG. 4, the movable ends 33, 33 are respectively provided with screws 35, 35 screwed laterally and screws 36, 3 screwed laterally with the mounting members 30, 30.
Clamping springs (clamping means) 37, 37 are attached between them. These pinching springs 37, 37 have a third force due to their restoring force.
It is urged in the direction of arrow A in the figure, whereby the clamping ends 32, 32 of the outer clamp pieces 27, 27 press the outer surface of the inner clamp pieces 26, 26 when the bag is clamped. Becomes The sandwiching ends 32 of the inner clamp piece 26 and the outer clamp 27 are adjusted in advance so that their widths are sufficiently shorter than the width of the mouth of the bag for opening.

The fixed frame 24 is a quadrilateral provided on the base shaft 23, and the fixed frame 28 is arranged on one side thereof. Movable frame 25
Is also a quadrilateral, and the movable frame 29 is arranged on the same side as the fixed frame 28. The movable frame 25 includes bearing members 39, 39 whose side frames 38, 38 are attached to the fixed frame 24.
It is indirectly attached to the fixed frame body 24 by being slidably inserted into the fixed frame body 24 and is movably provided with respect to the fixed frame body 24. Further, the movable frame pair 25 is provided with a pressing mechanism such as a cam mechanism or an air cylinder for advancing and retracting the movable frame 29 on the side opposite to the movable frame 29.
It is provided as an opening mechanism (opening means) 49 for separating the 26, 26 from each other. With such a structure, the movable frame 29 moves to the position shown by the chain double-dashed line in FIG. 4 by operating the opening mechanism, and along with this movement, the inner clamp piece 26 provided on the movable frame 29. The outer clamp 27 and the outer clamp 27 are separated from the inner clamp piece 26 and the outer clamp piece 27 provided on the fixed frame 28.

The base shaft 23 supporting the fixed frame body 24 and the movable frame body 25 is provided with a moving mechanism (not shown) for moving the frame bodies and a rotating mechanism (not shown) for rotating the frame bodies.
As a result, the clamps 22, 22 provided on the fixed frame 28 and the movable frame 29 are moved to a place where a process is performed after the bag is opened as described later.

Further, when an air cylinder or the like is used as an opening mechanism for moving the movable frame body 25, the movable frame body 25 is returned to the initial position. For example, as shown in FIG. Means such as providing a return spring 40 inside 39 is adopted.

As shown in FIG. 5, the outer clamp pieces 27, 27 are pressed above the clamps 22, 22 to rotate the outer clamp pieces 27, 27 downward, and thereby, to the inner clamp pieces 26, 26 of the outer clamp pieces 27, 27. An opening mechanism 41 is arranged to open the contact. The opening mechanism 41 includes an air cylinder 42 provided on the base of
Piston rod 43 that extends above the air cylinder 42 and moves up and down
A mounting rod 44 provided at the tip of the piston rod 43, a pair of movable rods 45, 45 provided on the mounting rod 44, and the movable rods 45, 4 provided on the base together with the air cylinder 42.
The rod receiving member 46 is slidably inserted through the member 5, and the pressing members 47, 47 are provided at the lower ends of the movable rods 45, 45 for pressing the outer clamp pieces 27, 27. Based on such a configuration, the opening mechanism 41 lowers the movable rods 45, 45 by the air cylinder 42 and presses the movable ends 33, 33 of the outer clamp pieces 27, 27 by the pressing bodies 47, 47 to move them. Movable rod that keeps this state while rotating
By maintaining 45, 45 in that position, the contact of the outer clamp pieces 27, 27 with the inner clamp pieces 26, 26 is released.

Next, the operation of such a bag opening device will be described based on the bag opening step.

First, a bag made of a stretched film or the like is prepared, and the mouth of the bag is placed at the position of the locking claws 21, 21 shown by the chain double-dashed line in FIG. 1 with the bag slightly opened. Here, the locking claws 21, 21 are
It is in a state of being directed to the bag B in advance as shown in FIG. In addition, the rods 12 and 12 provided with the locking claws 21 and 21 are in a state in which the pressing mechanism portion 14 shown in FIG. 2 is operated in advance, and the rod receiving members 11 and 11 approach each other at a predetermined distance. By doing so, the bag B is kept at a distance sufficiently narrower than the width of the mouth of the bag. In this case, the bag B is manually opened and the catch claws 21 and 2 are engaged as described later.
Although it may be held at 1, it is more preferable to use the automatic opening machine 48 shown by the chain double-dashed line in FIG.

This automatic opening machine has a pair of adsorbents 48, 48 made of an elastic material such as rubber arranged above and below, and at least one of these adsorbents 48, 48 is vertically movable. Further, the adsorbents 48, 48 are horizontally movable. Then, in order to open the bag B by using the automatic opening machine having such a configuration, first, the vicinity of the mouth of the bag B is sucked by an adsorbent.
It is set between 48 and 48, and the adsorbents 48 and 48 are moved in the contacting direction to sandwich the bag B by these adsorbents 48 and 48. Next, by operating a negative pressure source (not shown) provided on the adsorbents 48, 48, the adsorbents 48, 48 adsorb both front and back surfaces of the bag, and the adsorbents 48, 48 are separated from each other to form the bag. To open. After that, the adsorbents 48, 48 are moved to lock the bag B on the claws 21,
Then, the bag B is moved to the position 21 and the opening of the bag B is externally inserted into the locking claws 21, 21. Here, in order to stop the movement of the adsorbents 48, 48, for example, a limit switch is arranged in advance at a predetermined position, and when the bag B comes to the position of the locking claws 21, 21, as shown in FIG. A configuration is adopted in which the adsorbents 48, 48 or another member provided on the adsorbents 48 presses the limit switch so that the movement is automatically stopped.

Next, the pressure on the rod receiving members 11, 11 by the pressing mechanism portion 14 is released, and the rod receiving members 11, 11 are respectively returned to their original positions by the restoring force of the return springs 13, 13, whereby the rods 12, 12 are separated by a predetermined distance. Then, the locking claws 21 and 21 provided on the rods 12 and 12 are
Along with the movement of the bag B, the bag B is held by pressing both ends of the mouth of the bag B from the inside to the outside. In this case, since the engaging pawls 21 and 21 press the bag B on both ends of the mouth portion merely by the restoring force of the return springs 13 and 13, excessive force is not applied to the bag B, and The inconvenience of tearing the bag B is prevented.

The predetermined interval between the locking claws 21 and 21 (or the rods 12 and 12) described above is determined in advance according to the width of the mouth of the bag B, and the sliding screw 7 shown in FIG. By rotating, the sliding members 8 and 8 are moved equidistantly in the opposite directions,
This is adjusted.

Then, a driving device (not shown) is driven to rotate the rotating member 2 by 90 °, and the rods 12 and 12 are moved to the positions shown by solid lines in FIG. The opened bag B is pulled up with its opening facing upward.

Prior to this, the clamps 22 and 22 are previously arranged at the positions shown by the chain double-dashed line in FIG. 1, and the outer clamp pieces 27 and 27 are respectively arranged as shown by the chain double-dashed line in FIG. Rotate to rotate the inner clamp pieces 26, 26 and the outer clamp pieces 27,
The sandwiching ends 32, 32 of 27 are sufficiently separated. Then, the bag B is held by the locking claws 21 and 21 by the rotation of the rotating member 2 and pulled up, so that both front and back surfaces of the mouth portion thereof enter the gaps between the inner clamp piece 26 and the outer clamp piece 27, respectively. Like In this case the outer clamp pieces 27,27
The rotation is performed by lowering the pressing body 47 of the opening mechanism 41 shown in FIG. 5 and maintaining its position as described above.

Next, the air cylinder 42 of the opening mechanism 41 is operated and the movable rods 45, 45 are raised to release the pressing of the pressing members 47, 47 on the outer clamp pieces 27, 27. Then, the outer clamp pieces 27, 27 are rotated in the direction of arrow A in FIG. 3 by the restoring force of the sandwiching springs 37, 37, and the sandwiching ends 32, 3
2 is the inner clamp piece 26 on both the front and back sides of the mouth of bag B,
It presses against the outer surface of 26, which clamps
22 and 22 are for sandwiching the front and back surfaces of the mouth of the bag B, respectively.

Also, after a short delay, the rotation mechanism section 17 is activated and the rod
12 and 12 are rotated to rotate the locking claws 21 and 21 inward by 90 °, respectively, and the pressing mechanism portion 14 is operated to press the rod receiving members 11 and 11 to move the rods 12 and 12. The bag B is moved so that the distance therebetween is sufficiently narrower than the width of the mouth of the bag B. Then, the holding of the bag B by the locking claws 21, 21 is released, and the bag B is held only by being clamped by the clamps 22, 22 as described above.

After that, the opening mechanism including the cam mechanism is actuated to move the movable frame 37 by a preset distance to clamp the clamps 22, 22.
Separate. Then, the bag B is opened to a sufficient size by pulling the front and back surfaces of the mouth portion as the clamps 22, 22 are separated. And in this case the outer clamp piece
Since the elastic bodies 34, 34 are attached to the sandwiching ends 32, 32 of the 27, 27, the sandwiched portion of the bag B is not damaged. Further, in the subsequent process, even if a downward force is applied to the clamps 22, 22 by putting the contents in the opened bag B, the bag B is
When the outer clamp pieces 27, 27 are pulled downward, the clamping ends 32, 32 are tightened (rotated) in the direction in which the inner clamp pieces 26, 26 are pressed, so that the bag B falls off the clamps 22, 22. There is nothing to do.

Further, after this, the rotation and movement mechanism of the base shaft 23 supporting the fixed frame body 24 is operated, and the opened bag B is moved to a place where a post-process such as putting an item such as vegetables in the bag is performed.

In such a bag opening device, since the process from opening the bag to moving to the subsequent process in that state is automatically performed, it is possible to open the bag quickly and accurately, which facilitates bag filling work. Acceleration can be promoted.

"Effects of the Invention" As described above, the bag opening device of the present invention is configured as described above, and the pair of locking claws are inserted into the mouth portion and locked to the locking claws by the action of the locking spring. Reattach the mouth of the bag to the front and back with each pair of inner clamp piece and outer clamp piece,
Since the bag is opened by moving the clamp pieces away from each other, the bag can be opened as large as possible and accurately, and thus the bag filling operation can be accelerated. Further, since the bag can be surely opened without being limited in thickness and strength of the bag, it can be sufficiently applied to a bag made of an inexpensive stretched film, and thus the cost of the bag packing operation can be reduced. .

[Brief description of drawings]

1 to 5 are views showing an embodiment of a bag opening device in a bag filling and packaging machine according to the present invention. FIG. 1 is a side sectional view showing a schematic structure of the opening device, and FIG. FIG. 3 is a partial cross-sectional view showing the schematic structure of the sliding mechanism section, FIG. 3 is a side view showing the schematic structure of the clamp and its arrangement structure, and FIG. 4 is a plan view showing the schematic structure of the clamp and its arrangement structure. FIG. 6 is a side view showing a schematic configuration of an opening mechanism. 1 ... Central axis, 2 ... Rotating member, 4 ... Sliding mechanism part, 7 ... Sliding screw, 8 ... Sliding member, 11 ... Rod receiving member, 12 ... Rod, 13 ... Return spring, 14 …… Pressing mechanism part, 17 …… Rotating mechanism part, 21 …… Locking claw, 24 …… Fixed frame body, 25 …… Movable frame body, 26 …… Inner clamp piece, 27 …… Outer side Clamp piece, 28 …… Fixed frame, 29 …… Movable frame, 37 …… Clamping spring, 41 …… Opening mechanism, B …… Bag.

Claims (1)

[Claims] 1. A support member (3) which rotates up and down around a central axis (1), and a pair of sliding members provided on the support member (3) so that the mutual space in the horizontal direction can be adjusted. (8,8),
A rod receiving member (11) provided on each sliding member (8) so as to be horizontally movable in the direction in which the sliding members (8) are arranged.
A rod (12) provided in each rod receiving member (11) so as to be rotatable in the circumferential direction with the axial direction orthogonal to the moving direction of the rod receiving member (11), and the rod (12) A locking claw (21) provided at the tip of the rod (12) so as to project in the radial direction, and a rotation for changing the direction of the locking claw (21) by rotating each rod (12) in the circumferential direction. The rod receiving member (11) is moved with respect to the sliding member (8) by a distance between the moving mechanism portion (17) and the pair of locking claws (21, 21) inserted in the mouth portion of the bag (B). The locking spring (1) that locks the bag (B) with the pair of locking claws (21, 21)
3) and each rod receiving member (11) is horizontally moved against the elastic force of the locking spring (13) with respect to the sliding member (8), and the distance between the pair of rods (12, 12) is increased. The pressing mechanism part (14) for narrowing the bag to prevent the bag (B) from being locked to the pair of locking claws (21, 21) and the sliding member (8) of the pair of rod receiving members (11, 11). A pair of frame bodies (24, 25) provided so as to be relatively movable in the horizontal direction orthogonal to the moving direction,
The frame members (24, 25) are arranged side by side in the relative movement direction of the frame members (24, 25), and the support member (3) about the central axis (1) is pivoted upward so that the mouth portion is upward. Pawl (21,2
1) A pair of inner clamp pieces (26, 26) inserted in the center of the mouth of the bag (B) suspended in 1), and an outer side rotatably attached to the outer side of each inner clamp piece (26). The clamp pieces (27) and the sandwiching ends (32) of the outer clamp pieces (27) are rotated toward the inner clamp pieces (26) so that the mouth of the bag (B) becomes the inner clamp pieces (26). Clamping means (37) for cooperatively clamping and the one frame body (25).
By moving the inner clamp piece (26) together with the outer clamp piece (27) in the above-mentioned arrangement direction of the inner clamp pieces (26, 26) by moving the inner clamp piece (26) with respect to the other frame body (24). An opening means (49) for opening the bag (B) and an opening mechanism (41) for rotating each outer clamp piece (27) with respect to the inner clamp piece (26) to release the sandwiching of the bag (B). An opening device for a bag in a bag filling and packaging machine, comprising: