Automatic paper bag turnover device for paper bag production line

Abstract

The invention relates to the technical field of paper bag production, in particular to an automatic paper bag turnover device for a paper bag production line, which comprises an operation box and a paper bag body, the inner wall of the operation box is rotatably connected with two rollers through two rotating shafts, one roller is connected with a first conveying belt, and the other roller is connected with a second conveying belt; and the turnover mechanism comprises a hollow rod rotationally connected to the inner wall of the operation box, two U-shaped plates are fixedly connected to the side wall of the hollow rod, and the lower surface of one U-shaped plate is right opposite to the upper surface of the first conveying belt. The positions of the two U-shaped plates are replaced by rotating a hollow rod forwards by half circle, at the moment, the beginning upper surface of an adsorbed paper bag body faces downwards, and the beginning lower surface of the adsorbed paper bag body faces upwards, so that the paper bag body can be conveyed out under the action of a second conveying belt, and the surface, not printed with patterns, of the paper bag body is printed; therefore, the front and back surfaces of the paper bag body are automatically overturned and conveyed.

Description

Technical Field

[0001] The present invention relates to the technical field of paper bag production, and particularly relates to an automatic paper bag flipping device for a paper bag production line. Background Art

[0002] There are many varieties of paper bags, various paper materials, and many styles, and there can be various display forms, such as white cardboard paper bags, white board paper bags, copperplate paper bags, kraft paper bags, etc. When processing paper bags, printing and painting are carried out on both the front and back sides, and it is necessary to turn them over.

[0003] In the prior art, when printing and painting both sides of a paper bag, it is carried out while moving on the production line. However, after printing and painting the front side of the paper bag, it is necessary for workers to manually flip the paper bag and then print and paint the back side. The labor intensity is high, and it is impossible to ensure the position consistency during the conveying process of the paper bag, which affects the printing and painting quality of the back side of the paper bag. Moreover, since the back side of the paper bag inevitably contaminates impurities after being conveyed on the production line, and these impurities are not cleaned after flipping, it affects the printing and painting quality of the back side of the paper bag again. Summary of the Invention

[0004] The purpose of the present invention is to solve the problems existing in the prior art, and to propose an automatic paper bag flipping device for a paper bag production line.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions: An automatic paper bag flipping device for a paper bag production line, comprising: An operation box and a paper bag body. Two rollers are rotatably connected to the inner wall of the operation box through two rotating shafts. A first conveyor belt is connected to one of the rollers, and a second conveyor belt is connected to the other roller; A flipping mechanism. The flipping mechanism includes a hollow rod rotatably connected to the inner wall of the operation box. Two U-shaped plates are fixedly connected to the side wall of the hollow rod. The lower surface of one of the U-shaped plates faces the upper surface of the first conveyor belt, and the upper surface of the other U-shaped plate is flush with the upper surface of the second conveyor belt. A strip-shaped cavity is opened in each of the two U-shaped plates. A plurality of adsorption holes penetrating the side wall of the U-shaped plate are opened on the inner wall of the strip-shaped cavity. The openings of the plurality of adsorption holes close to the first conveyor belt face downward, and the openings of the plurality of adsorption holes close to the second conveyor belt face upward. The inner walls of the two strip-shaped cavities are both communicated with the inner wall of the hollow rod through a first air suction pipe, and an air suction mechanism is provided on the operation box.

[0006] Preferably, the exhaust mechanism includes an L-shaped plate fixedly connected to the side wall of the operation box, the side wall of the L-shaped plate is fixedly connected with an exhaust pipe, the side wall of the exhaust pipe is sealed and rotatably connected to the inner wall of the hollow rod, the side wall of the exhaust pipe is provided with a first arc-shaped groove, and the side wall of the exhaust pipe away from the first arc-shaped groove is provided with a ventilation groove, the first exhaust pipe close to the first conveyor belt is opposite to the first arc-shaped groove, and the first exhaust pipe close to the second conveyor belt is opposite to the ventilation groove.

[0007] Preferably, solenoid valves are provided in the two first air extraction pipes, and sensors are installed on the side walls of the two U-shaped plates away from the hollow rod, and the sensors are electrically connected to the corresponding solenoid valves through an external control mechanism.

[0008] Preferably, a cleaning mechanism is provided on the C-shaped plate, and the cleaning mechanism includes a groove opened on the C-shaped plate away from the strip cavity, the inner wall of the groove is slidably connected to a C-shaped rod, and the side wall of the C-shaped rod is fixedly connected to a plurality of bristles, and the plurality of bristles are close to the side wall of the C-shaped plate.

[0009] Preferably, the side walls of the two U-shaped rods close to the bristles are fixedly connected with dust suction pipes, the inner walls of the two dust suction pipes are connected to the inner wall of the hollow rod through the second exhaust pipe, and the side walls of the exhaust pipe are provided with a second arc-shaped groove, and the second exhaust pipe close to the first conveyor belt is opposite to the second arc-shaped groove during rotation.

[0010] Preferably, the inner wall of the groove is rotatably connected to a reciprocating screw, the side wall of the reciprocating screw is threadedly connected to the side wall of the C-shaped rod, the side wall of the C-shaped plate away from the hollow rod is fixedly connected to a fixed plate, the side wall of the fixed plate is rotatably connected to a first bevel gear through a cross bar, the side wall of the reciprocating screw close to the fixed plate is fixedly connected to a second bevel gear, and the first bevel gear and the second bevel gear are meshed.

[0011] Preferably, an arc-shaped toothed plate is fixedly connected to the top of the operating box, and a first gear is fixedly connected to the side wall of the cross bar away from the first bevel gear, and the first gear meshes with the arc-shaped toothed plate during the rotation of the fixed plate.

[0012] Preferably, the side wall of the L-shaped plate is fixedly connected to a motor, the side wall of the motor output shaft is fixedly connected to a second gear, the side wall of the hollow rod is fixedly connected to a third gear, and the second gear and the third gear are meshed.

[0013] Preferably, the inner wall of the operation box close to the upper surface of the first conveyor belt and the second conveyor belt is provided with a frame opening, and the inner wall of the frame opening is symmetrically fixedly connected with a guide plate.

[0014] Preferably, two hot blowers are fixedly connected to the top of the operation box, and a box door is hinged on the side wall of the operation box.

[0015] Compared with the existing technology, the advantages of the present invention are as follows: 1. A flipping mechanism is provided. When the hollow rod rotates forward by half a turn to replace the positions of the two U-shaped plates, the initially upper surface of the adsorbed paper bag body will face downward, and the initially lower surface of the adsorbed paper bag body will face upward. And the first air suction pipe corresponding to the paper bag body will face the ventilation groove after rotating half a turn, so that the air pressure in the strip-shaped cavity returns to normal and no longer adsorbs the paper bag body, enabling the paper bag body to be conveyed out under the action of the second conveyor belt, and printing the surface of the paper bag body without printed patterns. Thus, the front and back sides of the paper bag body are automatically flipped and conveyed, avoiding the need for workers to manually flip the paper bag body and then print and spray paint on its back side at present, which has a large labor intensity and cannot ensure the position consistency of the paper bag body during the conveying process.

[0016] 2. A cleaning mechanism is provided. When the first gear meshes with the arc-shaped tooth plate following the rotation of the fixed plate, the first gear will drive the reciprocating lead screw to rotate through the cross bar, the first bevel gear and the second bevel gear, driving the U-shaped rod to move, so that the brush hairs located on the U-shaped rod clean the surface of the paper bag body without printed patterns, avoiding the inevitable contamination of impurities on the back side of the paper bag body during conveying on the production line in the prior art, and not cleaning these impurities after flipping it, which will affect the printing and spray painting quality of the back side of the paper bag body again.

[0017] 3. A dust suction pipe and a second air suction pipe are provided. When the U-shaped plate rotates to make the first gear mesh with the arc-shaped tooth plate, the second air suction pipe corresponding to the paper bag body faces the second arc-shaped groove. At this time, the second arc-shaped groove sucks air from the dust suction pipe through the second air suction pipe, and then, following the movement of multiple brush hairs, the impurities cleaned from the back side of the paper bag body can be absorbed, avoiding the flow of impurities in the operation box and resulting in a decline in the cleaning effect on the back side of the paper bag body. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of an automatic paper bag flipping device for a paper bag production line proposed by the present invention; Figure 2 is Figure 1 a vertical sectional structural diagram at two first air suction pipes in Figure 3 is Figure 2 a schematic enlarged structural diagram at A in Figure 4 is Figure 1 a vertical sectional structural diagram at two strip-shaped cavities in Figure 5 is Figure 4 a schematic enlarged structural diagram at B in Figure 6 is Figure 4 a schematic enlarged structural diagram at C in Figure 7 is Figure 1 the top view structural schematic diagram of the two U-shaped plates in Figure 8 is Figure 7 the enlarged structural schematic diagram of the D position in Fig. 9 is Figure 1 the rear view structural schematic diagram of

[0019] In the figure: 1. Operation box; 2. Roller; 3. First conveyor belt; 4. Second conveyor belt; 5. Paper bag body; 6. Hollow rod; 7. U-shaped plate; 8. Strip cavity; 9. Suction hole; 10. L-shaped plate; 11. Exhaust pipe; 12. First suction pipe; 13. First arc groove; 14. Ventilation groove; 15. Solenoid valve; 16. Sensor; 17. Groove; 18. U-shaped rod; 19. Brush hair; 20. Dust suction pipe; 21. Second suction pipe; 22. Second arc groove; 23. Reciprocating lead screw; 24. Fixed plate; 25. Cross bar; 26. First bevel gear; 27. Second bevel gear; 28. Arc-shaped tooth plate; 29. First gear; 30. Motor; 31. Second gear; 32. Third gear; 33. Frame opening; 34. Guide plate; 35. Hot air blower; 36. Box door. Specific embodiments

[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0021] Refer to Figure 1 - Fig. 9 , a paper bag automatic turning device for a paper bag production line, including an operation box 1 and a paper bag body 5. The inner wall of the operation box 1 is rotatably connected with two rollers 2 through two rotating shafts. A first conveyor belt 3 is connected to one of the rollers 2, and a second conveyor belt 4 is connected to the other roller 2.

[0022] It should be noted that the parts of the first conveyor belt 3 and the second conveyor belt 4 outside the operation box 1 in the present invention are connected to an external driving source (not shown in the figure).

[0023] Frame openings 33 are provided on the inner walls of the operation box 1 close to the upper surfaces of the first conveyor belt 3 and the second conveyor belt 4. Guide plates 34 are symmetrically and fixedly connected to the inner walls of the frame openings 33, which can ensure that the position of the paper bag body 5 corresponds before and after turning and there will be no phenomena such as inclination.

[0024] Two hot blowers 35 are fixedly connected to the top of the operating box 1, which can heat the paper bag body 5 turned over in the operating box 1 to facilitate drying the patterns printed and painted on the front of the paper bag body 5. The side wall of the operating box 1 is hinged with a box door 36.

[0025] The flip mechanism includes a hollow rod 6 rotatably connected to the inner wall of the operating box 1, and two shaped plates 7 are fixedly connected to the side wall of the hollow rod 6, wherein the lower surface of one shaped plate 7 is directly opposite to the upper surface of the first conveyor belt 3, and the upper surface of the other shaped plate 7 is flush with the upper surface of the second conveyor belt 4 (such as Figure 2 As shown), it should be noted that the lengths of the two rollers 2 are smaller than the distance between the side walls of the U-shaped plates 7, so that during the rotation of the two U-shaped plates 7, the first conveyor belt 3 and the second conveyor belt 4 will not collide.

[0026] The two U-shaped plates 7 are provided with a strip-shaped cavity 8, and the inner wall of the strip-shaped cavity 8 is provided with a plurality of adsorption holes 9 (such as Figure 5 As shown in the figure, multiple adsorption holes 9 near the first conveyor belt 3 open downward, and multiple adsorption holes 9 near the second conveyor belt 4 open upward. The inner walls of the two strip-shaped cavities 8 are connected to the inner wall of the hollow rod 6 through the first exhaust pipe 12, and an exhaust mechanism is provided on the operation box 1.

[0027] The exhaust mechanism includes an L-shaped plate 10 fixedly connected to the side wall of the operation box 1, and an exhaust pipe 11 (such as Fig. 9 As shown, the side wall of the exhaust pipe 11 is sealed and rotatably connected to the inner wall of the hollow rod 6, and the side wall of the exhaust pipe 11 is provided with a first arc groove 13 (as shown Figure 3 As shown in the figure, a ventilation groove 14 is provided on the side wall of the exhaust pipe 11 away from the first arc-shaped groove 13, the first exhaust pipe 12 close to the first conveyor belt 3 is opposite to the first arc-shaped groove 13, and the first exhaust pipe 12 close to the second conveyor belt 4 is opposite to the ventilation groove 14.

[0028] It should be noted that the exhaust pipe 11 is connected to the air inlet of the external negative pressure fan.

[0029] The two first exhaust pipes 12 are each provided with an electromagnetic valve 15 (such as Figure 3 As shown, the side walls of the two U-shaped plates 7 away from the hollow rod 6 are both equipped with sensors 16 (as shown in FIG. Figure 2 and Figure 7 As shown), the sensor 16 is electrically connected to its corresponding solenoid valve 15 through an external control mechanism.

[0030] When the sensor 16 does not sense the signal of the paper bag body 5 , the solenoid valve 15 corresponding to the sensor 16 is powered off and closed.

[0031] The motor 30 is fixedly connected to the side wall of the L-shaped plate 10 , the second gear 31 is fixedly connected to the side wall of the output shaft of the motor 30 , and the third gear 32 is fixedly connected to the side wall of the hollow rod 6 , and the second gear 31 and the third gear 32 are meshed.

[0032] The first conveyor belt 3 can convey the paper bag body 5 with a pattern printed on the front side (the surface without a pattern printed is attached to the first conveyor belt 3). When the paper bag body 5 is conveyed to the lower surface of the shaped plate 7, the sensor 16 located on the shaped plate 7 senses the signal of the paper bag body 5. At this time, the solenoid valve 15 corresponding to the sensor 16 is powered on and opened, and then the external negative pressure fan extracts air from the multiple adsorption holes 9 through the exhaust pipe 11, the first arc-shaped groove 13, the first exhaust pipe 12 and the strip cavity 8. At this time, under the action of negative pressure, the edge of the unprinted surface on the printed surface of the paper bag body 5 is adsorbed and attached to the lower surface of the shaped plate 7, and then the driving motor 30 is rotated half a circle in the forward direction, and then the hollow rod 6 is driven in the forward direction through the second gear 31 and the third gear 32. After rotating half a circle, the positions of the two Q-shaped plates 7 are changed. At this time, the surface of the adsorbed paper bag body 5 with the printed pattern will face downward, and the surface of the adsorbed paper bag body 5 without the printed pattern will face upward, and the first exhaust pipe 12 corresponding to the paper bag body 5 will face the ventilation groove 14 after rotating half a circle, so that the air pressure in the strip cavity 8 returns to normal and no longer adsorbs the paper bag body 5, so that the paper bag body 5 can be conveyed out under the action of the second conveyor belt 4, and the surface of the paper bag body 5 without the printed pattern is printed, thereby automatically turning over and conveying the front and back sides of the paper bag body 5, avoiding the current need for staff to manually turn over the paper bag body 5 and then print and spray paint on its back, which is labor-intensive and cannot ensure the position consistency of the paper bag body 5 during the conveying process.

[0033] The shaped plate 7 is provided with a cleaning mechanism, which includes a groove 17 (such as Figure 5 As shown in the figure), the inner wall of the groove 17 is slidably connected with a C-shaped rod 18, and the side wall of the C-shaped rod 18 is fixedly connected with a plurality of bristles 19, and the plurality of bristles 19 are close to the side wall of the C-shaped plate 7.

[0034] The inner wall of the groove 17 is rotatably connected to a reciprocating screw 23, and the side wall of the reciprocating screw 23 is threadedly connected to the side wall of the C-shaped rod 18. The side wall of the C-shaped plate 7 away from the hollow rod 6 is fixedly connected to a fixed plate 24, and the side wall of the fixed plate 24 is rotatably connected to a first bevel gear 26 through a cross bar 25. The side wall of the reciprocating screw 23 close to the fixed plate 24 is fixedly connected to a second bevel gear 27, and the first bevel gear 26 and the second bevel gear 27 are meshed.

[0035] The top of the operating box 1 is fixedly connected with an arc-shaped toothed plate 28 (such as Figure 4 As shown in the figure, the side wall of the cross bar 25 away from the first bevel gear 26 is fixedly connected with the first gear 29, and the first gear 29 meshes with the arc-shaped toothed plate 28 during the rotation of the fixed plate 24.

[0036] During the rotation of the two U-shaped plates 7 driven by the hollow rod 6, the two fixing plates 24 drive the two first gears 29 to rotate at this time. When the first gear 29 meshes with the arc-shaped tooth plate 28 following the rotation of the fixing plate 24, the first gear 29 drives the reciprocating lead screw 23 to rotate through the cross bar 25, the first bevel gear 26 and the second bevel gear 27, driving the U-shaped rod 18 to move, so that the bristles 19 on the U-shaped rod 18 clean the surface of the paper bag body 5 without printed patterns. When the first gear 29 meshes with and then separates from the arc-shaped tooth plate 28 following the rotation of the fixing plate 24, the U-shaped rod 18 moves back and forth on the side wall of the reciprocating lead screw 23 to the initial position, which will not affect the normal removal of the subsequent paper bag body 5, realizing the cleaning of the reverse side of the paper bag body 5, avoiding the inevitable contamination of impurities on the reverse side of the paper bag body 5 after being conveyed on the production line in the prior art, and not cleaning these impurities after flipping it, which will affect the printing and painting quality of the reverse side of the paper bag body 5 again.

[0037] Vacuum suction pipes 20 are fixedly connected to the side walls of the two U-shaped rods 18 close to the bristles 19, and the inner walls of the two vacuum suction pipes 20 are communicated with the inner wall of the hollow rod 6 through second suction pipes 21 (as Figure 8 shown), and a second arc-shaped groove 22 is formed in the side wall of the exhaust pipe 11, and the second suction pipe 21 close to the first conveyor belt 3 is aligned with the second arc-shaped groove 22 during rotation.

[0038] When the U-shaped plate 7 rotates to make the first gear 29 mesh with the arc-shaped tooth plate 28, the second suction pipe 21 corresponding to the paper bag body 5 is aligned with the second arc-shaped groove 22 at this time. At this time, the second arc-shaped groove 22 sucks air from the vacuum suction pipe 20 through the second suction pipe 21, and then, following the movement of the plurality of bristles 19, the impurities cleaned from the reverse side of the paper bag body 5 can be absorbed, avoiding the flow of impurities in the operation box 1 and resulting in a decrease in the cleaning effect on the reverse side of the paper bag body 5.

[0039] After the front side of the paper bag body 5 is printed with a pattern, the first conveyor belt 3 can convey the paper bag body 5 with the front side printed pattern into the operation box 1. When the paper bag body 5 is conveyed to the lower surface of the U-shaped plate 7, the sensor 16 located on the U-shaped plate 7 senses the signal of the paper bag body 5 at this time. At this time, the solenoid valve 15 corresponding to the sensor 16 is electrified and opened. Then, the external negative pressure blower sucks air through the exhaust pipe 11, the first arc-shaped groove 13, the first air extraction pipe 12 and the strip-shaped cavity 8 from the plurality of adsorption holes 9. At this time, under the action of negative pressure, the edge of the unprinted surface on the printed surface of the paper bag body 5 is adsorbed and attached to the lower surface of the U-shaped plate 7. Subsequently, the driving motor 30 rotates forward half a turn, and then drives the hollow rod 6 to rotate forward half a turn through the second gear 31 and the third gear 32, changing the positions of the two U-shaped plates 7. At this time, the surface of the paper bag body 5 with the printed pattern will face down, and the surface of the paper bag body 5 without the printed pattern will face up. And after the first air extraction pipe 12 corresponding to the paper bag body 5 rotates half a turn, it will be aligned with the ventilation groove 14, so that the air pressure in the strip-shaped cavity 8 returns to normal and no longer adsorbs the paper bag body 5, enabling the paper bag body 5 to be conveyed out under the action of the second conveyor belt 4, and printing the surface of the paper bag body 5 without the printed pattern. Thus, the front and back sides of the paper bag body 5 are automatically flipped and conveyed, avoiding the need for workers to manually flip the paper bag body 5 and then print and spray paint its back side at present, which has a large labor intensity and cannot ensure the position consistency of the paper bag body 5 during the conveying process; At the same time, during the flipping process of the paper bag body 5, the two hot air blowers 35 can heat-treat the paper bag body 5 flipped in the operation box 1 to facilitate drying the patterns printed and spray-painted on the front side of the paper bag body 5; During the process of the hollow rod 6 driving the two U-shaped plates 7 to rotate, at this time, the two fixing plates 24 drive the two first gears 29 to rotate. When the first gear 29 meshes with the arc-shaped tooth plate 28 following the rotation of the fixing plate 24, the first gear 29 will drive the reciprocating lead screw 23 to rotate through the cross bar 25, the first bevel gear 26 and the second bevel gear 27, driving the U-shaped rod 18 to move, so that the bristles 19 located on the U-shaped rod 18 clean the surface of the paper bag body 5 without the printed pattern. And when the first gear 29 meshes with the arc-shaped tooth plate 28 and then separates following the rotation of the fixing plate 24, the U-shaped rod 18 moves back and forth on the side wall of the reciprocating lead screw 23 to the initial position, which will not affect the normal removal of the subsequent paper bag body 5, realizing the cleaning of the back side of the paper bag body 5, avoiding the inevitable contamination of impurities on the back side of the paper bag body 5 after being conveyed on the production line in the prior art, and not cleaning these impurities after flipping it, which will affect the printing and spray painting quality of the back side of the paper bag body 5 again; When the U-shaped plate 7 rotates so that the first gear 29 is meshed with the arc-shaped toothed plate 28, the second exhaust pipe 21 corresponding to the paper bag body 5 is opposite to the second arc-shaped groove 22. At this time, the second arc-shaped groove 22 draws air from the dust suction pipe 20 through the second exhaust pipe 21, and then follows the movement of the multiple bristles 19 to absorb the impurities cleaned from the back of the paper bag body 5, thereby preventing the impurities from flowing in the operating box 1, resulting in a decrease in the cleaning effect on the back of the paper bag body 5.

[0040] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An automatic paper bag turning device for a paper bag production line, characterized in that: Including: An operation box (1) and a paper bag body (5), wherein two rollers (2) are rotatably connected to the inner wall of the operation box (1) through two rotating shafts. A first conveyor belt (3) is connected to one of the rollers (2), and a second conveyor belt (4) is connected to the other roller (2); A flipping mechanism, which includes a hollow rod (6) rotatably connected to the inner wall of the operation box (1). Two U-shaped plates (7) are fixedly connected to the side wall of the hollow rod (6). The lower surface of one of the U-shaped plates (7) faces the upper surface of the first conveyor belt (3), and the upper surface of the other U-shaped plate (7) is flush with the upper surface of the second conveyor belt (4). Strip-shaped cavities (8) are opened in both of the U-shaped plates (7). A plurality of adsorption holes (9) penetrating through the side wall of the U-shaped plate (7) are opened on the inner wall of the strip-shaped cavity (8). The openings of the plurality of adsorption holes (9) close to the first conveyor belt (3) face downward, and the openings of the plurality of adsorption holes (9) close to the second conveyor belt (4) face upward. The inner walls of both of the strip-shaped cavities (8) are communicated with the inner wall of the hollow rod (6) through a first air suction pipe (12), and an air extraction mechanism is provided on the operation box (1).

2. The automatic paper bag turning device for a paper bag production line according to claim 1, characterized in that: The air extraction mechanism includes an L-shaped plate (10) fixedly connected to the side wall of the operation box (1). An exhaust pipe (11) is fixedly connected to the side wall of the L-shaped plate (10). The side wall of the exhaust pipe (11) is hermetically and rotatably connected to the inner side wall of the hollow rod (6). A first arc-shaped groove (13) is opened on the side wall of the exhaust pipe (11). An air ventilation groove (14) is opened on the side wall of the exhaust pipe (11) far from the first arc-shaped groove (13). The first air suction pipe (12) close to the first conveyor belt (3) is aligned with the first arc-shaped groove (13), and the first air suction pipe (12) close to the second conveyor belt (4) is aligned with the air ventilation groove (14).

3. The automatic paper bag turning device for a paper bag production line according to claim 1, characterized in that: Solenoid valves (15) are arranged in both of the first air suction pipes (12). Sensors (16) are installed on the side walls of both of the U-shaped plates (7) far from the hollow rod (6). The sensors (16) are electrically connected to their corresponding solenoid valves (15) through an external control mechanism.

4. The automatic paper bag turning device for a paper bag production line according to claim 2, characterized in that: A cleaning mechanism is provided on the U-shaped plate (7). The cleaning mechanism includes a groove (17) opened on the U-shaped plate (7) far from the strip-shaped cavity (8). A U-shaped rod (18) is slidably connected to the inner wall of the groove (17). A plurality of brush hairs (19) are fixedly connected to the side wall of the U-shaped rod (18). The plurality of brush hairs (19) are close to the side wall of the U-shaped plate (7).

5. The automatic paper bag turning device for a paper bag production line according to claim 4, characterized in that: Suction pipes (20) are fixedly connected to the side walls of both of the U-shaped rods (18) close to the brush hairs (19). The inner walls of both of the suction pipes (20) are communicated with the inner wall of the hollow rod (6) through a second air suction pipe (21). A second arc-shaped groove (22) is opened on the side wall of the exhaust pipe (11). The second air suction pipe (21) close to the first conveyor belt (3) is aligned with the second arc-shaped groove (22) during rotation.

6. The automatic paper bag turning device for a paper bag production line according to claim 4, characterized in that: The inner wall of the groove (17) is rotatably connected to a reciprocating screw (23), the side wall of the reciprocating screw (23) is threadedly connected to the side wall of the C-shaped rod (18), the side wall of the C-shaped plate (7) away from the hollow rod (6) is fixedly connected to a fixing plate (24), the side wall of the fixing plate (24) is rotatably connected to a first bevel gear (26) via a cross bar (25), the side wall of the reciprocating screw (23) close to the fixing plate (24) is fixedly connected to a second bevel gear (27), and the first bevel gear (26) and the second bevel gear (27) are meshed with each other.

7. The automatic paper bag turning device for a paper bag production line according to claim 6, characterized in that: An arc-shaped toothed plate (28) is fixedly connected to the top of the operating box (1), and a first gear (29) is fixedly connected to the side wall of the cross bar (25) away from the first bevel gear (26). The first gear (29) meshes with the arc-shaped toothed plate (28) during the rotation of the fixed plate (24).

8. The automatic paper bag turning device for a paper bag production line according to claim 2, characterized in that: A motor (30) is fixedly connected to the side wall of the L-shaped plate (10), a second gear (31) is fixedly connected to the side wall of the output shaft of the motor (30), a third gear (32) is fixedly connected to the side wall of the hollow rod (6), and the second gear (31) and the third gear (32) are meshed with each other.

9. The automatic paper bag turning device for a paper bag production line according to claim 1, characterized in that: The inner wall of the operation box (1) close to the upper surface of the first conveyor belt (3) and the second conveyor belt (4) is provided with a frame opening (33), and the inner wall of the frame opening (33) is symmetrically fixedly connected with a guide plate (34).

10. The automatic paper bag turning device for a paper bag production line according to claim 1, characterized in that: Two hot blowers (35) are fixedly connected to the top of the operation box (1), and a box door (36) is hingedly connected to the side wall of the operation box (1).

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