Plastic bag tri-folding device and plastic bag folding method

Abstract

A plastic bag three-fold folding device and a plastic bag folding method, comprising a primary folding mechanism for folding two carrying straps at the front end of a vest-shaped plastic bag toward the middle, characterized in that a secondary folding mechanism for folding the rear part of the plastic bag from the bottom to the front is provided behind the primary folding mechanism, and a tertiary folding mechanism provided above the primary folding mechanism and for folding the middle of the plastic bag after the secondary folding in half. The advantages of the present invention are: greatly simplifying the structure, reducing the manufacturing cost, not prone to failure, reducing the maintenance cost; simplifying the folding process, and improving the work efficiency.

Description

Technical Field

[0001] The invention relates to a component of a plastic bag making machine, in particular to a plastic bag three-folding device and a plastic bag folding method. Background Art

[0002] The main structure of the folding device of the bag making machine of the prior art (such as "high-speed bag making machine", announcement number: N210759499U) includes: a front corner folding mechanism for folding the two carrying straps at the front end of the vest-shaped plastic bag product to the middle; a front folding plate for folding the front part of the plastic bag product backward, and a bag pressing hook capable of swinging upward and backward is provided in the middle of the front end of the front folding plate; a rear folding plate for folding the rear part of the plastic bag product forward; the front corner folding mechanism is arranged in front of the front folding plate, and a rear folding plate is provided behind the front folding plate; two parallel guide plates are provided below between the front folding plate and the rear folding plate, and two side pressing plates with openings facing each other and capable of moving up and down and relatively are respectively provided above the two ends of the guide plate; an n-shaped bracket connected to the two side frames is provided above the guide plate, and a plug plate is installed below the n-shaped bracket, and a front indentation plate and a rear indentation plate are respectively provided in front and behind the plug plate, and the plug plate, the front indentation plate and the rear indentation plate are respectively connected through a driving cylinder and a guide rod installed on the n-shaped bracket. An intermediate pressing plate is arranged above the rear part of the frame, and the rear part of the intermediate pressing plate is connected to an intermediate pressing plate driving device which can drive the intermediate pressing plate to deflect and move forward and backward.

[0003] The disadvantages of the above-mentioned existing folding devices are complex structure, high cost, high failure rate, complex folding process and low working efficiency. Summary of the invention

[0004] The present invention aims to provide a plastic bag tri-folding device to solve the problems of complex structure, high cost and high failure rate in the prior art.

[0005] The technical solution of the present invention is: a three-fold folding device for plastic bags, including a primary folding mechanism for folding two carrying straps at the front end of a vest-shaped plastic bag toward the middle, characterized in that a secondary folding mechanism for folding the rear part of the plastic bag from the bottom to the front is provided behind the primary folding mechanism, and a tertiary folding mechanism is provided above the primary folding mechanism and is used to fold the middle of the plastic bag after the secondary folding.

[0006] A plastic bag folding method using the plastic bag tri-folding device is characterized by comprising the following steps:

[0007] 1) One-time folding: using the one-time folding mechanism, fold the two straps at the front end of the vest-shaped plastic bag toward the middle below;

[0008] 2) Secondary folding: using the secondary folding mechanism to fold the rear part of the plastic bag from the bottom to the front after the primary folding;

[0009] 3) Three-folding: The three-folding mechanism is used to press the second-folded plastic bag downward from the middle to achieve a V-shaped fold.

[0010] The advantages of the present invention are: greatly simplified structure, reduced manufacturing cost, less prone to failure, reduced maintenance cost; simplified folding process, improved work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the overall structure of the basic structure embodiment of the present invention ( Figure 2 AA section view);

[0012] Figure 2 yes Figure 1 A top view of

[0013] Figure 3 It is a structural schematic diagram of the bag pressing mechanism of the present invention ( Figure 1 Right side view of the medium pressure bag mechanism);

[0014] Figure 4 It is a schematic diagram of the three-dimensional structure of a dual-channel embodiment of the present invention (excluding the plastic bag output device);

[0015] Figure 5 yes Figure 4 A top view of

[0016] Figure 6 yes Figure 4 Schematic diagram of the three-dimensional structure from another angle;

[0017] Figure 7 It is a schematic diagram of the working process of the present invention;

[0018] Figure 8 yes Figure 7 Figure (b) shows a folded handle on the back.

[0019] Description of the accompanying drawings: 1, frame, 2, pallet moving track, 3, slider, 4, rear pallet, 41, rear pallet notch, 5, secondary plug-in plate track, 6, slider, 7, secondary plug-in plate, 71, long hole, 8, cylinder bracket, 9, bag pressing mechanism driving cylinder, 10, block driving cylinder, 11, tertiary plug-in plate driving cylinder, 12, bag pressing mechanism, 121, U-shaped plate, 122, pressure rod, 123, elastic body; 13, front block, 14, tertiary Insert plate, 15. Left and right sliding plates, 151. Notch, 16. Horizontal track, 17. Longitudinal track, 18. Output track, 19. U-shaped bayonet, 20. Front support plate, 21. Track support rod, 22. Frame beam, 23. Guide rod, 24. Rear pressure strip drive cylinder, 25. Rear pressure strip, 26. Moving bottom plate, 27. Up and down conveying mechanism, 271. Bayonet, 272. Lifting cylinder, S. Plastic bag, S1, (plastic bag) carrying strap. DETAILED DESCRIPTION

[0020] See also Figure 1-Figure 3 The basic structure of a three-fold folding device for a plastic bag of the present invention is a single-path (one channel), comprising a primary folding mechanism for folding two carrying straps at the front end of a vest-shaped plastic bag toward the middle, characterized in that a secondary folding mechanism for folding the rear part of the plastic bag from the bottom to the front is provided behind the primary folding mechanism, and a tertiary folding mechanism for folding the middle of the plastic bag after the secondary folding is provided above the primary folding mechanism and the secondary folding mechanism.

[0021] The one-folding mechanism includes a rear support plate 4 and left and right sliding plates 15. The rear support plate 4 can move forward and backward along the support plate moving track 2 fixed on the frame 1 in the front and rear direction under the drive of the rear support plate driving device. The front end of the rear support plate 4 is a 45° isosceles triangle, and a rear support plate notch 41 is provided at the front end of the isosceles triangle; the front ends of the two left and right sliding plates 15 are respectively slidably mounted on two transverse rails 16, the transverse rails 16 are mounted on a moving bottom plate 26, and the bottom of the moving bottom plate 26 is slidably mounted on a longitudinal rail 17, and the longitudinal rail 17 is mounted on the frame 1; the two left and right sliding plates 15 can move relatively along the two transverse rails 16 under the drive of the driving device; the moving bottom plate 26 and the two transverse rails 16 can move forward and backward along the two longitudinal rails 17 under the drive of the driving device. A notch 151 is provided at the rear end of the left and right sliding plates 15.

[0022] The rear support plate driving device is driven by a servo motor through a synchronous belt.

[0023] The secondary folding mechanism comprises a front pressure block 13, a front support plate 20, a rear pressure strip 25 and a secondary plug-in plate 7 which can move forward and backward along the secondary plug-in plate track 5 under the drive of a driving device. The secondary plug-in plate track 5 is located below the support plate moving track 2 and is installed on the frame 1; a long hole 71 corresponding to the tertiary plug-in plate 14 of the tertiary folding mechanism is provided at the front of the secondary plug-in plate 7; the front pressure block 13 is installed at the bottom end of the piston rod of the pressure block driving cylinder 10, and the pressure block driving cylinder 10 is installed above the frame 1 through the cylinder bracket 8; the rear pressure strip 25 is installed at the lower end of the piston rod of the rear pressure strip driving cylinder 24, and the rear pressure strip driving cylinder 24 is installed on the cylinder bracket 8 and is located behind the pressure block driving cylinder 10; the front end of the front support plate 20 is connected to the movable bottom plate 26 and is located above the left and right sliding plates 15.

[0024] The three-folding mechanism includes a bag pressing mechanism 12 and a three-fold inserting plate 14. The bag pressing mechanism 12 is located in front of the rear pressure strip 25. The bag pressing mechanism 12 is composed of a U-shaped plate 121, a pressure rod 122 and an elastic body 123. The horizontal U-shaped plate 121 is installed at the bottom end of the piston rod of a bag pressing mechanism driving cylinder 9. The opening of the U-shaped plate 121 faces the front end. The front pressing block 13 corresponds to the opening of the U-shaped plate 121. A pressure rod 122 is provided below each of the two sides of the front end of the U-shaped plate 121. An elastic body 123 (such as a rubber band or a spiral spring, whose two ends are respectively connected between the two pressure rods 122; or a cylinder spring sheet, etc.) is provided between the two pressure rods 122; the upper side of the three-fold inserting plate 14 is connected to the lower end of the piston rod of the three-fold inserting plate driving cylinder 11; the bag pressing mechanism driving cylinder 9 and the three-fold inserting plate driving cylinder 11 are both installed on the cylinder bracket 8.

[0025] A plastic bag output device for outputting the folded plastic bag to the back is provided below the three-stage plug board 14, and the plastic bag output device includes a U-shaped bayonet 19, an output track 18, and an up-down conveying mechanism 27. The output track 18 is horizontally arranged in the front-to-back direction, and the U-shaped bayonet 19 is provided with an elastic throat, and moves forward and backward along the output track 18 under the drive of the driving device. An up-down conveying mechanism 27 is provided below the three-stage plug board 14 and between the two U-shaped bayonet 19. The top of the up-down conveying mechanism 27 is provided with a bayonet 271 corresponding to the three-stage plug board 14, and the bayonet 271 is installed at the top of a lifting cylinder 272. The function of the up-down conveying mechanism 27 is that after the three-stage plug board 14 pushes the folded plastic bag S downward, before it is sent into the U-shaped bayonet 19, if there is no bayonet 271 to receive it, the plastic bag S is suspended and will fall off the three-stage plug board 14. With the support of the bayonet 271, as the tertiary plug plate 14 moves downward, the plastic bag S is transported to the U-shaped bayonet 19, thereby preventing the plastic bag S from falling off.

[0026] A guide rod 23 in the same direction as the tertiary plunger driving cylinder 11 is provided on both sides thereof. The bottom end of the guide rod 23 slides through the cylinder bracket 8 and is connected to the upper side of the tertiary plunger 14 .

[0027] See also Figure 4-Figure 6 , is a specific application embodiment of the present invention, which is a dual-path (two processing channels), wherein the driving device of the two-path tertiary plugboard 14 adopts the same set of devices as the previous embodiment (a tertiary plugboard driving cylinder 11 and two guide rods 23). In addition, the left and right sliding plates 15 of the two paths adopt a set of driving devices, which is a conventional technology. The other parts are basically two sets of the previous embodiment in one frame 1.

[0028] See also Figure 7 and Figure 8 , the working process of the present invention (an example of the folding method of the present invention) is described as follows:

[0029] (1) One-time folding: The robot moves from the front ( Figure 1 and Figure 2 The vest-shaped plastic bag S processed by the punching process (right end in the middle) is transported to the upper side of the rear support plate 4 which has been moved forward to the lower side (slightly to the rear) of the cylinder support 8 ( Figure 7 Then, the rear pressure strip 25 moves downward to press the middle of the plastic bag S (before this, the secondary plug board 7 can also move forward to drag the strap S1 of the plastic bag S to prevent the strap S1 from sagging and causing the plastic bag S to deviate irregularly; after the rear pressure strip 25 presses the plastic bag S, the secondary plug board 7 moves backward), and the strap S1 naturally sags (as shown in FIG. Figure 7 Then the two left and right sliding plates 15 move relative to each other in sequence, folding the two carrying straps S1 from the bottom of the rear support plate 4 to the middle (see Figure 8 After the first folding, the front support plate 20 is located below the rear support plate notch 41 , and the left and right sliding plates 15 are located on the left and right sides of the front support plate 20 .

[0030] (2) Secondary folding: The front pressing block 13 moves downward to press the bottom of the U-shaped opening of the plastic bag S onto the front supporting plate 20, and the rear supporting plate 4 moves backward to cause the rear part of the plastic bag S to sag downward; the secondary inserting plate 7 moves forward to fold the sag portion of the rear part of the plastic bag S forward from the bottom (see Figure 7 ce diagram), complete the secondary folding.

[0031] (3) Three-folding: The bag pressing mechanism 12 moves downward, and the elastic body 123 presses the portion between the two unloaded and folded carrying straps S1 of the plastic bag S; the two pressing rods 122 are located in front of the plastic bag S (corresponding to the notches 151 of the left and right sliding plates 15), and their function is to prevent the plastic bag S from moving forward with the left and right sliding plates 15 and the front supporting plate 20 when the left and right sliding plates 15 and the front supporting plate 20 move forward and reset (see Figure 7 f); the front pressing block 13 moves up and resets (the left and right sliding plates 15 and the front supporting plate 20 move forward and reset, see Figure 7 g); when the front pressing block 13 starts to move up and reset, the tongue part in the middle of the plastic bag S will not be tilted up due to the presence of the elastic body 123 on the bag pressing mechanism 12, and when the left and right sliding plates 15 move forward, the tilted tongue of the plastic bag caused by the height difference will also be pressed downward under the action of the elastic body 123, and the plastic bag S will not be driven forward due to the forward movement of the left and right sliding plates 15, and the rear support plate 4 moves forward to the back of the bag pressing mechanism 12 (the purpose is to block the rear part of the plastic bag S to prevent the top of the plastic bag S from opening when the bag pressing mechanism 12 moves up), and then when the three-stage plug plate 14 moves down to close to the plastic bag S (generally 1-3cm), the bag pressing mechanism 12 moves up (see Figure 7 h), the tertiary plug plate 14 moves downward to push the middle part of the plastic bag S downward into the long hole 71 of the secondary plug plate 7, and the plastic bag S that has been folded twice is folded in half again, completing the third folding.

[0032] After the three-folded plastic bag S is output from the bottom of the long hole 71, it is sent into the U-shaped bayonet 19 of the plastic bag output device with the support of the upper and lower conveying mechanisms 27, and then the U-shaped bayonet 19 moves backward along the output track 18 to convey the folded plastic bag S to the next bundling process, which is completed by an automatic bundling device or manually.

Claims

1. A plastic bag folding method using a plastic bag three-folding device, the plastic bag three-folding device comprising a primary folding mechanism for folding two carrying straps at the front end of a vest-shaped plastic bag toward the middle, a secondary folding mechanism for folding the rear part of the plastic bag from the bottom to the front, and a tertiary folding mechanism provided above the primary folding mechanism and the secondary folding mechanism for folding the middle of the plastic bag after the secondary folding in half; It is characterized in that The plastic bag folding method comprises the following steps: 1) One-time folding: using the one-time folding mechanism, fold the two straps at the front end of the vest-shaped plastic bag toward the middle below; 2) Secondary folding: using the secondary folding mechanism to fold the rear part of the plastic bag from the bottom to the front after the primary folding; 3) Three-folding: The three-folding mechanism is used to press the second-folded plastic bag downward from the middle to achieve a V-shaped fold.

2. The plastic bag folding method according to claim 1, characterized in that: The one-time folding mechanism comprises a rear support plate (4) and left and right sliding plates (15); the rear support plate (4) can move forward and backward along a support plate moving track (2) fixed on a frame (1) in a front-to-back direction under the drive of a rear support plate driving device; the front end of the rear support plate (4) is a 45° isosceles triangle, and a rear support plate notch (41) is provided at the front end of the isosceles triangle; the front ends of the two left and right sliding plates (15) are respectively slidably mounted on two transverse rails (16), and the rear ends of the left and right sliding plates (15) are provided with a notch (151); the transverse rail (16) is mounted on a movable bottom plate (26), and the bottom of the movable bottom plate (26) is slidably mounted on a longitudinal rail (17), and the longitudinal rail (17) is mounted on the frame (1); the two left and right sliding plates (15) can move relative to each other along the two transverse rails (16) under the drive of the driving device; the two transverse rails (16) can move forward and backward along the two longitudinal rails (17) under the drive of the driving device.

3. The plastic bag folding method according to claim 2, characterized in that: The rear support plate driving device is driven by a servo motor through a synchronous belt.

4. The plastic bag folding method according to claim 2, characterized in that: The secondary folding mechanism comprises a front pressure block (13), a front support plate (20), a rear pressure strip (25) and a secondary plug plate (7) which can move forward and backward along a secondary plug plate track (5) under the drive of a driving device, wherein the secondary plug plate track (5) is located below the support plate moving track (2) and is mounted on a frame (1); a long hole (71) corresponding to the tertiary plug plate (14) of the tertiary folding mechanism is provided at the front of the secondary plug plate (7); the front pressure block (13) is mounted on the bottom end of the piston rod of a pressure block driving cylinder (10), and the pressure block driving cylinder (10) is mounted on the top of the frame (1) through a cylinder bracket (8); the rear pressure strip (25) is mounted on the bottom end of the piston rod of the rear pressure strip driving cylinder (24), and the rear pressure strip driving cylinder (24) is mounted on the cylinder bracket (8) and is located behind the pressure block driving cylinder (10); the front end of the front support plate (20) is connected to the movable bottom plate (26) and is located above the left and right sliding plates (15).

5. The plastic bag folding method according to claim 4, characterized in that: The three-folding mechanism comprises a bag pressing mechanism (12) and a three-folding plate (14). The bag pressing mechanism (12) is located in front of the rear pressure strip (25). The bag pressing mechanism (12) is composed of a U-shaped plate (121), a pressure rod (122) and an elastic body (123). The horizontal U-shaped plate (121) is installed at the bottom end of the piston rod of a bag pressing mechanism driving cylinder (9). The opening of the U-shaped plate (121) faces the front end. The front pressure block (13) corresponds to the opening of the U-shaped plate (121). Pressure rods (122) are respectively provided under the two sides of the front end of the U-shaped plate (121). An elastic body (123) is provided between the two pressure rods (122). The upper side of the three-folding plate (14) is connected to the lower end of the piston rod of the three-folding plate driving cylinder (11). The bag pressing mechanism driving cylinder (9) and the three-folding plate driving cylinder (11) are both installed on the cylinder bracket (8).

6. The plastic bag folding method according to claim 4, characterized in that: A plastic bag output device for outputting folded plastic bags to the rear is provided below the tertiary plug plate (14), the plastic bag output device comprising a U-shaped bayonet (19), an output track (18) and an up-down conveying mechanism (27), the output track (18) being arranged horizontally along the front-back direction, the U-shaped bayonet (19) being provided with an elastic throat, and being driven by a driving device to move forward and backward along the output track (18); an up-down conveying mechanism (27) is provided below the tertiary plug plate (14) and between the two U-shaped bayonet (19), the top end of the up-down conveying mechanism (27) being provided with a bayonet (271) corresponding to the tertiary plug plate (14), the bayonet (271) being mounted on the top end of a lifting cylinder (272).

7. The plastic bag folding method according to claim 5, characterized in that: A guide rod (23) is provided on each of the left and right sides of the tertiary plunger driving cylinder (11) in the same direction as the tertiary plunger driving cylinder (11). The bottom end of the guide rod (23) slides through the cylinder bracket (8) and is connected to the upper side of the tertiary plunger (14).

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