Inner bag twisting device of double-layer packaging bag

Abstract

The invention relates to a packaging machine, in particular to a double-layer packaging bag inner bag twisting device which comprises a base, a vertical main shaft is arranged on the base, the lower end of the main shaft is connected with a bag clamping mechanism through a connecting base, and the bag clamping mechanism comprises two swing rods with the upper ends hinged to the connecting base. The two swing rods are arranged in an included angle mode with openings facing downwards, clamping units are arranged at the lower ends of the swing rods, the lower ends of the swing rods are connected with horizontally-arranged overhanging rods, the rod length direction of the overhanging rods and the plane where the swing paths of the swing rods are located are arranged in an included angle mode, and the clamping units are arranged at the overhanging ends of the overhanging rods. By means of the arrangement of the overhanging rod, an action space which is enough for the clamping arms to open and release the inner bag closing bundle is reserved between the clamping unit located at the overhanging end of the overhanging rod and the swing rod, interference between the swing rod and the clamping arms is avoided, and normal operation of inner bag twisting operation is guaranteed.

Description

Technical Field

[0001] This invention relates to packaging machines, and more specifically to a twisting device for the inner bag of a double-layer packaging bag. Background Technology

[0002] Plastic woven bags are mainly composed of polypropylene and polyethylene tapes, which are woven together to form the product. They have great advantages in structural strength and flexibility, but their sealing performance is not good. Especially when loading powder materials, double-layer bags are required for sealing. The inner layer is a plastic film bag for sealing, and the double-layer combination achieves both sealing and load-bearing capacity.

[0003] The patent document entitled "A Rotary Gripper for a Packaging Machine" (publication number CN221795082U, hereinafter referred to as Document 1) discloses a solution including a winding motor base, a stepper motor mounted on the upper end of the winding motor base, a coupling mounted on the bottom output end of the stepper motor through the bottom of the winding motor base, an air slip ring set on the outside of the coupling, and slip ring fixing plates fixedly mounted on both ends of the bottom of the winding motor base respectively; by setting a stepper motor on the upper end of the winding motor base, its bottom output end drives the coupling to drive the transmission shaft, which in turn drives the slip ring connecting seat to rotate the bottom clamping assembly, while the cylinder in the clamping assembly drives the swing arm to open and close, thereby causing the gripper to clamp and rotate the object.

[0004] After the inner bags of the packaging bag are gathered into a bundle, the above-mentioned technical solution uses a swing arm to drive the grippers to hold the inner bag's closing bundle, thus twisting the inner bag and forming a twisted bundle at the bag opening, thereby improving the bag's sealing performance. In automated packaging operations, the closing bundle of the packaging bag is usually delivered by a gripping arm to the area below the grippers in the twisting station. The bag opening above the gripping arm lacks proper support and is in a very loose, unfolded state. Therefore, the grippers in the twisting station should not grip the bag body at this location but rather the inner bag body below the gripping arm. After the grippers hold the inner bag's closing bundle, the gripping arm needs to open to separate from it. This is why, in the above-mentioned reference 1, the opening action of the straight-arm swing arm after holding the bag's closing bundle interferes with the swing arm in the gripping assembly, preventing the gripping arm from opening and the grippers from twisting the inner bag's closing bundle. Summary of the Invention

[0005] This invention provides a double-layer packaging bag inner bag twisting device to avoid interference with the clamping arm of the inner bag closing bundle, thereby effectively twisting the inner bag closing bundle of the packaging bag.

[0006] To achieve the above objectives, the technical solution adopted is as follows: a double-layer packaging bag inner bag torsion device, including a base, a vertically positioned main shaft on the base, a bag clamping mechanism connected to the lower end of the main shaft via a connecting seat, the bag clamping mechanism including two swing rods hinged to the connecting seat at their upper ends, the two swing rods arranged at an angle with their openings facing downwards, and a clamping unit provided at the lower end of the swing rods, the swing paths of the clamping units being coplanar, a first driving unit driving the main shaft to rotate around itself as the rotation axis, a second driving unit driving the lower ends of the two swing rods to swing closer to or further away from each other, a horizontally placed cantilever rod connected to the lower end of the swing rod, the length direction of the cantilever rod being arranged at an angle to the plane of the swing path of the swing rod, the clamping unit being located at the cantilever end of the cantilever rod and the slots on the clamping unit being opposite each other, the center of the hole area formed by the slots on the clamping unit being concentric with the main shaft.

[0007] Compared with the prior art, the technical effects of the present invention are as follows: the lower end of the swing arm in the bag clamping mechanism is connected to a horizontally placed extension rod. By using the extension rod, sufficient space is left between the clamping unit at the extension end of the extension rod and the swing arm for the clamping arm to open and release the inner bag closing bundle, avoiding interference between the swing arm and the clamping arm. At the same time, since the center of the hole area formed by the clamping slots on the clamping unit for clamping the inner bag closing bundle is concentric with the main shaft, when the main shaft drives the bag clamping mechanism to twist the inner bag closing bundle, the twisting axis of the inner bag closing bundle is almost consistent with the main shaft. This avoids the situation where the inner bag closing bundle will have a large swaying motion during twisting, which would prevent the twisting operation from being carried out smoothly, thus ensuring the normal operation of the inner bag twisting operation. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the structure of the present invention;

[0009] Figure 2 This is a three-dimensional appearance diagram of the present invention;

[0010] Figure 3 This is a schematic diagram showing the position of the clamp arm when the lever is closed.

[0011] Figure 4 Main axis diagram;

[0012] Figure 5 A schematic diagram showing the clamping units on the two cantilever rods in the closed state;

[0013] Figure 6 A schematic diagram showing the opening formed by the bayonet's enclosure;

[0014] Figure 7 This is a schematic diagram showing the clamping position of the clamping unit on the inner bag closing strap. Detailed Implementation

[0015] The following is in conjunction with the appendix Figure 1-7The present invention will be further described in detail below, including related content:

[0016] A double-layer packaging bag inner bag twisting device includes a base 10, on which a vertical main shaft 20 is mounted. The lower end of the main shaft 20 is connected to a bag clamping mechanism 30 via a connecting seat 21. The bag clamping mechanism 30 includes two swing rods 31 whose upper ends are hinged to the connecting seat 21. The two swing rods 31 are arranged at an angle with their openings facing downwards, and a clamping unit 32 is provided at the lower end of each swing rod 31. The swing paths of the clamping units 32 are coplanar, preventing the two clamping units 32 from misaligning in a direction perpendicular to the swing path of the swing rods 31 when they are closed, thus avoiding failure to clamp the inner bag's closing bundle A. When the situation occurs, the first drive unit 40 drives the main shaft 20 to rotate around itself as the rotation axis, and the second drive unit 50 drives the lower ends of the two swing arms 31 to swing towards or away from each other. The lower ends of the swing arms 31 are connected to a horizontally placed extension rod 33. The length direction of the extension rod 33 is arranged at an angle to the plane where the swing path of the swing arm 31 is located. The clamping unit 32 is set at the extension end of the extension rod 33 and the slots 321 on the clamping unit 32 are opposite to each other. The center of the hole area formed by the slots 321 on the clamping unit 32 is concentric with the main shaft 20.

[0017] Combination Figure 3 and Figure 7 As shown, in the above technical solution, the lower end of the swing rod 31 in the bag clamping mechanism 30 is connected to the horizontally placed extension rod 33. By utilizing the setting of the extension rod 33, sufficient space is left between the clamping unit 32 at the extension end of the extension rod 33 and the rod body of the swing rod 31 for the clamping arm B to open and release the inner bag closing bundle A, thus avoiding interference between the clamping arm B and the swing rod 31. At the same time, when the two clamping units 32 on the two extension rods 33 are combined, the center of the hole area formed by the slots 321 on the two clamping units 32 for clamping the inner bag closing bundle A is concentric with the main shaft 20. When the main shaft 20 drives the bag clamping mechanism 30 to twist the inner bag closing bundle A, the twisting axis of the inner bag closing bundle A is almost consistent with the main shaft 20, thus avoiding the situation where the inner bag closing bundle A will have a large swaying motion during twisting, which would prevent the twisting operation from being carried out smoothly, thereby ensuring the normal operation of the inner bag closing bundle A twisting operation.

[0018] Furthermore, the lower section of the swing arm 31 is bent to form a bent section 311. The extension rod 33 is connected to the lower end of the bent section 311. The bent section 311 and the extension rod 33 are coplanar and surround each other to form a notch 312. The two notches 312 are symmetrically arranged on both sides of the vertical plane passing through the axis of the main shaft 20 and perpendicular to the swing path of the swing arm 31. The opening directions of the two notches 312 are consistent, opposite to each other, or somewhere between consistent and opposite to each other.

[0019] In this design, a notch 312 is provided to allow space for the clamping arm B to be inserted, so that the bag-releasing action of the clamping arm B avoids the movement of the swing arm 31. This design includes three different forms:

[0020] Firstly, the opening directions of the two notches 312 are consistent, which indicates that the extension rod 33 is perpendicular to the plane of the swing path of the pendulum rod 31. For example... Figure 3 and Figure 7 As shown, when the two swing rods 31 are closed, the horizontally placed clamping arm B can open and close within the notch 312 when it swings horizontally. The swing path of the clamping arm B can avoid the swing rods 31. Even if the clamping arm B swings a large amplitude, it will not interfere with the swing rods 31.

[0021] Secondly, the opening directions of the two notches 312 are opposite to each other, which means that the bent section 311 and the cantilever rod 33 are located in the plane of the swing path of the swing rod 31. When the two swing rods 31 are closed, the clamping arm B is located in the area formed by the two notches 312. When the horizontally placed clamping arm B swings and opens in this area, it can be opened at a certain angle so that the inner bag drawstring A can be separated from the gap between the two clamping arms B. It is not necessary to fully open the clamping arm B. Then, the clamping arm B is controlled to withdraw from the area formed by the two notches 312.

[0022] Third, the opening directions of the two notches 312 are between being consistent with each other and being opposite to each other, which means that the plane where the swing path of the cantilever rod 33 and the swing rod 31 is located forms a non-perpendicular angle arrangement. This scheme is similar to the first scheme mentioned above, except that the opening direction of the notch 312 is not perpendicular to the plane where the swing path of the swing rod 31 is located.

[0023] As a preferred option, such as Figure 3 As shown, the length direction of the extension rod 33 is perpendicular to the plane containing the swing path of the pendulum rod 31. This is the design form described above where the opening directions of the two notches 312 are aligned.

[0024] Regarding the specific hinge method of the rocker arm 31, combined with Figure 1 As shown, a vertically arranged cylinder 51 is connected to the lower end of the connecting seat 21. The piston rod extension end of the cylinder 51 is located at the bottom, and the rod end of the piston rod is hinged to the upper middle part of the swing rod 31 through the connecting rod 52. The swing path of the swing rod 31 is located in the vertical plane, and the axis of each hinge is perpendicular to the plane where the swing path of the swing rod 31 is located. By controlling the extension and retraction of the piston rod of the cylinder 51, the swing rod 31 can be pulled down or lifted by the connecting rod 52, thereby controlling the swing rod 31 to close or open.

[0025] Considering that the movement of the lever 31 is driven by the cylinder 51, the entire bag clamping mechanism 30 needs to rotate several times (including the cylinder 51). Therefore, the air supply line of the cylinder 51 may experience excessive twisting. Thus, a slip ring 60 is fitted onto the main shaft 20. A pressurized air source supplies air to the cylinder 51 through the slip ring 60. The fixed ring of the slip ring 60 is connected to the base 10 via a connector 70. The moving ring of the slip ring 60 is fixedly connected to the main shaft 20, and the moving ring is located below the fixed ring. The fixed ring of the slip ring 60 can remain stationary, while the moving ring of the slip ring 60 can rotate synchronously with the entire bag clamping mechanism 30. The moving ring of the slip ring 60 and the cylinder 51 will not rotate relative to each other, and the air supply line between them will not twist, thus not affecting normal air supply.

[0026] Furthermore, the connector 70 includes a mounting plate 71 located below the base 10. The mounting plate 71 is fixedly connected to the base 10 via a connecting post 72. The upper end of the fixed ring of the air slip ring 60 is connected to the mounting plate 71. The spindle 20 passes through a through hole in the mounting plate 71 and is positioned in a mutually abutting position with the mounting plate 71. The mounting plate 71 is used as a carrier to install the fixed ring of the air slip ring 60, and the mounting plate 71 is fixed to the base 10 via the connecting post 72, ensuring the stability of the fixed ring posture of the air slip ring 60.

[0027] As a preferred embodiment, a platform 11 is provided above the base 10. The first drive unit 40 includes a motor 41 mounted on the platform 11. The upper end of the main shaft 20 passes through the base 10 and extends upward. The output shaft of the motor 41 is coaxially connected to the upper end of the main shaft 20 through a coupling 42. The coupling 42 includes an upper half 421 and a lower half 422. The upper half 421 is connected to the output shaft of the motor 41, and the lower half 422 is connected to the upper end of the main shaft 20. The upper half 421 and the lower half 422 form a limiting fit with circumferential limiting and axial sliding.

[0028] The main shaft 20 is driven to rotate by a motor 41, thereby controlling the rotational movement of the bag clamping mechanism 30. The output shaft of the motor 41 is connected to the main shaft 20 via a coupling 42. The upper half 421 and the lower half 422 of the coupling 42 form a circumferential limiting and axial sliding limiting fit. This allows the output shaft of the motor 41 to output torque only to the main shaft 20, while the weight of the main shaft 20 and the entire bag clamping mechanism 30 is borne by the base 10, effectively preventing the output bearing of the motor 41 from being easily damaged by excessive axial tension.

[0029] The upper half 421 and the lower half 422 are respectively provided with axially extending teeth and grooves that interlock with each other. Therefore, the coupling 42 is actually composed of end face toothed chucks interlocking with each other.

[0030] As a preferred embodiment, a vertically positioned bushing 80 is installed in the through hole on the base 10 through which the main shaft 20 passes. The bushing 80 is connected to the base 10 and fitted onto the main shaft 20. Bearings 81 are provided at both the upper and lower ends of the bushing 80, and the main shaft 20 forms a rotational fit with the bushing 80 through the bearings 81. In this embodiment, the weight of the bag clamping mechanism 30 is transmitted to the base 10 through the bearings 81 and the bushing 80. The bushing 80 provides reliable rotational support for the main shaft 20 and the bag clamping mechanism 30 below it.

[0031] As a preferred solution, combined with Figure 2 , Figure 5 , Figure 6 as well as Figure 7 As shown, the clamping unit 32 includes first and second clamping plates 32a and 32b respectively disposed on the cantilever ends of the two cantilever rods 33. The slots 321 are disposed at the middle position of the adjacent side plate edges of the first clamping plate 32a and the second clamping plate 32b. When the second driving unit 50 drives the first clamping plate 32a and the second clamping plate 32b to a position close to each other, the first clamping plate 32a and the second clamping plate 32b are vertically staggered and arranged close to each other. The slots 321 on the first clamping plate 32a and the second clamping plate 32b form a hole, and the projection of the openings of the slots 321 on the two plates on the horizontal plane partially overlaps.

[0032] In this design, the latches 321 on the first clamping plate 32a and the second clamping plate 32b are not horizontally aligned to form the opening for restraining the inner bag drawstring A. Instead, the first clamping plate 32a and the second clamping plate 32b are vertically offset. This is because if the adjacent side plates of the two first clamping plates 32a and the second clamping plate 32b are simply brought into contact, the opening formed by the two latches 321 may be too large to provide reliable clamping force for the non-rigid inner bag drawstring A, thus making it impossible to twist the inner bag drawstring A. Therefore, in this scheme, when the second driving unit 50 drives the first clamping plate 32a and the second clamping plate 32b to a position close to each other, the first clamping plate 32a and the second clamping plate 32b are vertically offset and arranged close to each other. The slots 321 on the first clamping plate 32a and the second clamping plate 32b form a hole, and the projection of the opening area of ​​the slots 321 on the horizontal plane partially overlaps. This makes the area of ​​the hole formed by the two slots 321 smaller than the sum of the opening areas of the two slots 321 themselves, so that the slots 321 can more reliably clamp the non-rigid inner bag drawstring A.

[0033] It should be noted that the notch 321 can be a V-shaped notch, which can effectively constrain and concentrate the inner bag closing bundle A; secondly, while ensuring that the notch 321 will not cause pressure damage to the inner bag closing bundle A, the area of ​​the hole formed by the two notches 321 can be minimized as much as possible to provide reliable clamping constraint for the inner bag closing bundle A.

[0034] Furthermore, two first clamping plates 32a are provided and arranged opposite each other. A receiving groove is formed between the opposite side plates of the two first clamping plates 32a for the insertion of the second clamping plate 32b. This enables the formation of a three-layer clamping plate design with mutual misalignment, which provides reliable clamping constraint for the inner bag drawstring A.

Claims

1. A double-layer packaging bag inner bag twisting device, comprising a base (10), a vertically positioned main shaft (20) is provided on the base (10), and a bag clamping mechanism (30) is connected to the lower end of the main shaft (20) via a connecting seat (21). The bag clamping mechanism (30) includes two swing rods (31) with their upper ends hinged to the connecting seat (21). The two swing rods (31) are arranged in an angle with their openings facing downwards, and a clamping unit (32) is provided at the lower end of the swing rods (31). The swing paths of the clamping units (32) are coplanar. A first driving unit (40) drives the main shaft (20) to rotate around itself as the rotation axis, and a second driving unit (50) drives the lower ends of the two swing rods (31) to swing towards or away from each other. The device is characterized in that: The lower end of the swing arm (31) is connected to a horizontally placed extension rod (33). The length direction of the extension rod (33) is arranged at an angle to the plane where the swing path of the swing arm (31) is located. The clamping unit (32) is set at the extension end of the extension rod (33) and the slots (321) on the clamping unit (32) are opposite to each other. The center of the hole area formed by the slots (321) on the clamping unit (32) is concentric with the main shaft (20).

2. The double-layer packaging bag inner bag twisting device according to claim 1, characterized in that: The lower section of the pendulum (31) is bent to form a bent section (311). The extension rod (33) is connected to the lower end of the bent section (311). The bent section (311) and the extension rod (33) are coplanar and surround to form a notch (312). The two notches (312) are symmetrically arranged on both sides of the vertical plane passing through the axis of the main shaft (20) and perpendicular to the swing path of the pendulum (31). The opening directions of the two notches (312) are consistent, opposite to each other, or between consistent and opposite to each other.

3. The double-layer packaging bag inner bag twisting device according to claim 1 or 2, characterized in that: The length direction of the extension rod (33) is perpendicular to the plane of the swing path of the pendulum rod (31).

4. The double-layer packaging bag inner bag twisting device according to claim 1, characterized in that: The lower end of the connecting seat (21) is connected to a vertically arranged cylinder (51). The piston rod extension end of the cylinder (51) is located below, and the rod end of the piston rod is hinged to the upper middle part of the swing rod (31) through the connecting rod (52). The swing path of the swing rod (31) is located in the vertical plane, and the core of each hinge axis is perpendicular to the plane where the swing path of the swing rod (31) is located.

5. The double-layer packaging bag inner bag twisting device according to claim 4, characterized in that: A slip ring (60) is fitted on the spindle (20). A pressure air source supplies air to the cylinder (51) through the slip ring (60). The fixed ring of the slip ring (60) is connected to the base (10) through a connector (70). The moving ring of the slip ring (60) is fixedly connected to the spindle (20) and the moving ring of the slip ring (60) is located below the fixed ring.

6. The double-layer packaging bag inner bag twisting device according to claim 5, characterized in that: The connector (70) includes a mounting plate (71) located below the base (10). The mounting plate (71) is fixed to the base (10) via a connecting post (72). The upper end of the fixed ring of the air slip ring (60) is connected to the mounting plate (71). The spindle (20) passes through the through hole on the mounting plate (71) and is positioned to avoid contact with the mounting plate (71).

7. The double-layer packaging bag inner bag twisting device according to claim 1, characterized in that: A platform (11) is provided above the base (10). The first drive unit (40) includes a motor (41) mounted on the platform (11). The upper end of the main shaft (20) passes through the base (10) and extends upward. The output shaft of the motor (41) is coaxially connected to the upper end of the main shaft (20) through a coupling (42). The coupling (42) includes an upper half (421) and a lower half (422). The upper half (421) is connected to the output shaft of the motor (41), and the lower half (422) is connected to the upper end of the main shaft (20). The upper half (421) and the lower half (422) form a limiting fit with circumferential limiting and axial sliding.

8. The double-layer packaging bag inner bag twisting device according to claim 7, characterized in that: The upper half (421) and the lower half (422) are respectively provided with axially extending teeth and grooves that interlock with each other.

9. The double-layer packaging bag inner bag twisting device according to claim 7, characterized in that: A vertical bushing (80) is provided in the through hole on the base (10) through which the main shaft (20) passes. The bushing (80) is connected to the base (10) and is fitted on the main shaft (20). Bearings (81) are provided at the upper and lower ends of the bushing (80). The main shaft (20) and the bushing (80) are rotated together through the bearings (81).

10. The double-layer packaging bag inner bag twisting device according to claim 1, characterized in that: The clamping unit (32) includes a first and a second clamping plate (32a, 32b) respectively disposed on the cantilever ends of the two cantilever rods (33). The slot (321) is disposed at the middle position of the adjacent side plate of the first clamping plate (32a) and the second clamping plate (32b). When the second driving unit (50) drives the first clamping plate (32a) and the second clamping plate (32b) to be in a position close to each other, the first clamping plate (32a) and the second clamping plate (32b) are vertically misaligned and arranged close to each other. The slots (321) on the first clamping plate (32a) and the second clamping plate (32b) form a hole and the projection of the opening of the slots (321) on the two plates on the horizontal plane partially overlaps.

11. The double-layer packaging bag inner bag twisting device according to claim 10, characterized in that: Two first clamping plates (32a) are provided and arranged with their surfaces facing each other. A receiving groove for inserting a second clamping plate (32b) is formed between the opposite side surfaces of the two first clamping plates (32a).

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