A pre-folding mechanism for a bag sewing machine

Abstract

The utility model discloses a kind of preposed edge folding mechanisms of bag sewing machine, including the bag sewing machine positionedly set on conveying belt, be provided with an edge folder before bag sewing machine, edge folder includes front and rear interval setting inner clamping plate and outer clamping plate, interval gap between inner clamping plate and outer clamping plate is bag mouth guide slit, front guide pulley and rear guide pulley are respectively provided with in bag mouth guide slit two sides along bag mouth guide slit and open distance by bracket one before and after, the belt of certain width is twisted and wound on front guide pulley and rear guide pulley across bag mouth guide slit spiral, twisted and wound across bag mouth guide slit spiral of the belt of certain width is obliquely twisted and wound downwards, twisted and wound is that the width side surface of belt is twisted and wound on the upper end of bag mouth guide slit and faces and sticks to inner clamping plate to the winding of rear guide pulley with twisted turning 180 degrees, a motor drives front guide pulley or rear guide pulley rotation, and packaging bag mouth into edge folder is twisted and folded with belt and sent into bag sewing machine.

Description

Technical Field

[0001] This utility model relates to a front-mounted folding mechanism for a bag sewing machine. Background Technology

[0002] When sealing woven bags (commonly known as snakeskin bags) after packaging materials, the bag opening needs to be folded 180 degrees before being fed into the sewing machine for a more secure seal and to prevent leakage. Currently, the folding method uses a guide rod and a twisted, irregularly shaped component at the sewing machine's entry point to gradually change the woven bag opening from a vertical position to 180 degrees. During this gradual folding process, the front and back sides of the woven bag rub against the guide rod. Furthermore, to accommodate longer woven bags, the folding device needs to be longer. Therefore, this folding mechanism has two drawbacks: first, the frictional resistance causes wrinkles at the bag opening, affecting the sealing quality, especially noticeable with softer woven bags; second, the longer folding mechanism occupies more equipment space. Summary of the Invention

[0003] To address the aforementioned problems, the purpose of this utility model is to provide a front-mounted folding mechanism for a bag sewing machine, which uses a dual-roller active rotation method for folding, thereby improving the existing folding mechanisms that suffer from wrinkles due to friction and occupy equipment space.

[0004] To achieve the above objectives, the solution of this utility model is as follows: A pre-fading mechanism for a bag sewing machine includes a bag sewing machine positioned above a conveyor belt. The conveyor belt transports packaging bags to be sealed. The bag sewing machine seals the bag opening. A fading machine is positioned before the bag sewing machine to fold the bag opening of the transported packaging bag 180 degrees before feeding it into the bag sewing machine for sealing. The fading machine includes two clamping plates spaced apart, referred to as an inner clamping plate and an outer clamping plate. The gap between the inner and outer clamping plates forms a bag opening guide seam. A front guide wheel and a rear guide wheel are respectively mounted on a bracket on both sides of the bag opening guide seam, spaced apart. The front guide wheel faces the bag opening as it enters the bag opening guide seam. The belt is positioned on the outer clamping plate side, and the rear guide wheel is positioned on the inner clamping plate side before the sewing machine. A belt of a certain width is looped on the front guide wheel and the rear guide wheel. The belt looped on the front guide wheel faces the bag opening and crosses the bag opening guide seam, twisting 180 degrees backward and wrapping from the rear guide wheel to the front guide wheel. The twisting 180-degree twisting makes the rotation directions of the front guide wheel and the rear guide wheel exactly opposite. The twisting 180-degree twisting of the belt across the bag opening guide seam is a downward twisting. The twisting is such that the wider side of the belt turns 180 degrees at the upper end of the bag opening guide seam and wraps against the inner clamping plate to the rear guide wheel. A motor drives the front guide wheel or the rear guide wheel to rotate.

[0005] The solution is further as follows: the rear guide wheel is driven by a motor and is called the driving wheel, while the front guide wheel is the driven wheel. The bottom axial end of the front guide wheel is higher than or equal to the bag opening guide seam on the outer clamping plate side, so that the width direction of the twisted belt is higher than the bag opening guide seam on the outside of the bag opening guide seam. The upper axial end of the rear guide wheel is higher than or level with the bag opening guide seam on the inner clamping plate side, so that the upper end of the belt fitted on the rear guide wheel is flush with the bag opening guide seam.

[0006] A further aspect of the solution is that the rotational speed of the belt driven by the motor is greater than or equal to the speed at which the conveyor belt transports the packaging bags.

[0007] A further step in the solution is that the distance between the front guide wheel and the rear guide wheel, which are pulled apart one after the other, is such that the belt twists and turns 180 degrees to face the inner clamp plate, and the length of the belt is not less than 200mm.

[0008] The beneficial effects of this utility model are as follows: The folding mechanism adopts a dynamic, gradual change method using bolted rollers. Two guide rollers twist a belt at a certain angle, causing the woven bag opening to gradually rotate 180 degrees as it enters the sewing machine. Simultaneously, one guide roller is mounted on the motor output shaft, providing power to the belt. This creates dynamic friction between the back of the woven bag and the belt, ensuring that the speed and stroke of the woven bag opening requiring folding are consistent with the conveyor. Folding while moving keeps the woven bag opening neat as it enters the sewing machine, guaranteeing a wrinkle-free sewing process. This utility model can be used on semi-automatic and automatic packaging equipment. Its ingenious design occupies little space, has a long service life, and is widely applicable.

[0009] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the structure of this utility model at the end of the packaging bag; Figure 3 This is a schematic diagram of the structure of this utility model at the end of the packaging bag; Figure 4 This is a schematic diagram of the axial structure of this utility model in one direction; Figure 5 This is a schematic diagram of the axial structure of this utility model from another direction; Figure 6 This is a schematic diagram of the structure of this utility model without the two clamping plates. Detailed Implementation

[0011] A front-mounted folding mechanism for a bag sewing machine, such as Figures 1 to 6As shown, the pre-sewing edge folding mechanism of the sewing machine includes a sewing machine 2 positioned on a conveyor belt 1. The conveyor belt 1 is used to transport packaging bags 3 to be sealed on the packaging line. The sewing machine 2 is used to seal the edge of the bag opening 301. A folding machine 4 is set before the bag inlet of the sewing machine 2. The folding machine 4 is used to fold the bag opening 301 of the conveyed packaging bag by 180 degrees and then send it into the sewing machine 2 to seal the edge of the bag opening 301. The folding machine 4 includes two clamping plates 401 arranged at intervals, which are referred to as inner clamping plates 401. The inner clamping plate 401-1 and the outer clamping plate 401-2 are folded at 90 degrees for easy installation. The installation bracket is omitted in the figure. The gap between the inner clamping plate 401-1 and the outer clamping plate 401-2 is the bag opening guide seam 402. On both sides of the bag opening guide seam 402, a front guide wheel 403 and a rear guide wheel 404 are respectively installed through the bracket 5. The front guide wheel 403 faces the end face of the bag opening 301 of the packaging bag entering the bag opening guide seam 402 and is placed on the outside of the outer clamping plate 401-2. The rear guide wheel 404 is positioned on the outer side of the inner clamping plate 401-1 before the sewing machine 2. A belt 6 of a certain width is fitted onto the front guide wheel 403 and the rear guide wheel 404. The belt 6, fitted onto the front guide wheel 403 and facing the bag opening 301, crosses the bag opening guide seam 402 and undergoes a 180-degree twist, winding backward from the rear guide wheel 404 to the rear of the front guide wheel 403. This 180-degree twist ensures that the rotation directions of the front guide wheel 403 and the rear guide wheel 404 are exactly opposite. The belt 6 crosses the bag opening guide seam 402. The 180-degree twisted winding of 2 is a downward twisted winding. The downward twisted winding is such that the side of the belt width turns 180 degrees at the upper end of the bag opening guide seam 402 and is wrapped against the inner clamping plate 401-1 to the rear guide wheel 404. A motor 7 drives the front guide wheel 403 or the rear guide wheel 404 to rotate. The bracket 5 has a mechanism for adjusting the up and down and front and back positions of the front guide wheel 403 and the rear guide wheel 404, which is not shown in the figure. The hole for mounting the guide wheel shaft is an elongated hole. The guide wheel is adjusted in the up and down position on the guide wheel shaft by the upper and lower limit.

[0012] In this embodiment, since the rear guide wheel 404 is the main force-bearing guide wheel, the rear guide wheel 404 is driven to rotate by the motor 7 and is called the driving wheel. The front guide wheel 403 is the driven wheel. The bottom axial end of the front guide wheel 403 is higher than or equal to the upper port of the bag opening guide seam 402 on the side of the outer clamping plate 401-2, so that the width direction of the twisted belt is higher than the bag opening guide seam 402 on the outside of the bag opening guide seam 402. The upper axial end of the rear guide wheel 404 is higher than or level with the upper port of the bag opening guide seam 402 on the side of the inner clamping plate 401-1, so that the upper end of the belt on the rear guide wheel 404 is flush with the upper port of the bag opening guide seam 402.

[0013] In order to prevent wrinkles from appearing after folding, the rotation speed of the belt 6 driven by the motor 7 is slightly greater than or equal to the speed at which the conveyor belt 1 transports the packaging bag. The wrinkles can be eliminated by adjusting the rotation speed of the belt 6 relative to the conveyor belt 1 through the motor 7.

[0014] In this embodiment, the distance between the front guide wheel 403 and the rear guide wheel 404 is such that the belt 6 is twisted and turned 180 degrees to face and adhere to the inner clamping plate 401-1, and there is a certain length, which can be about 100mm. For better effect, this embodiment has a distance of not less than 200mm.

[0015] in: The belt extending above the bag opening guide seam 402 is used to affix to the bag opening 301 of the packaging bag that moves into the bag opening guide seam 402; The upper end of the belt 6 on the side of the rear guide wheel 404 is flush with the bag opening guide seam 402. It is used to guide the bag opening 301 of the packaging bag to the rear guide wheel 404 after the belt 6 twists and turns 180 degrees to face the inner clamping plate 401-1. Then, it sends the folded bag opening 301 of the packaging bag out and guides it to the sewing machine 2.

[0016] When wrinkles appear at the folded edge, the wrinkles can be eliminated by adjusting the rotation speed of the belt driven by motor 7.

[0017] In the aforementioned embodiment of the front-mounted folding mechanism for the bag sewing machine, two guide wheels twist a belt at a certain angle, causing the woven bag opening to gradually rotate 180 degrees as it enters the sewing machine. Simultaneously, one of the guide wheels is mounted on the motor output shaft, providing power to the belt. This creates dynamic friction between the rear side of the woven bag and the belt, ensuring that the speed and stroke of the bag opening requiring folding are synchronized with the conveyor. Folding occurs simultaneously with movement, keeping the woven bag opening neat as it enters the sewing machine, guaranteeing a wrinkle-free sewing process. This mechanism can be used on semi-automatic and automated packaging equipment.

Claims

1. A pre-fading mechanism for a bag sewing machine, comprising a bag sewing machine (2) positioned above a conveyor belt (1), the conveyor belt (1) for conveying a packaging bag (3) to be sealed, the bag sewing machine (2) for sealing the opening (301) of the packaging bag, and a fading machine (4) positioned before the bag sewing machine (2), the fading machine (4) for folding the opening (301) of the conveyed packaging bag by 180 degrees and then feeding it into the bag sewing machine (2) to seal the opening (301) of the packaging bag, characterized in that, The folding machine (4) includes two clamping plates (401) spaced apart, referred to as the inner clamping plate (401-1) and the outer clamping plate (401-2). The gap between the inner clamping plate (401-1) and the outer clamping plate (401-2) is the bag opening guide seam (402). A front guide wheel (403) and a rear guide wheel (404) are respectively set on the bracket (5) along the bag opening guide seam (402) with a distance between them. The front guide wheel (403) faces the bag opening (301) of the packaging bag entering the bag opening guide seam (402) and is placed on the side of the outer clamping plate (401-2). The rear guide wheel (404) is placed on the side of the inner clamping plate (401-1) before the sewing machine (2). A belt (6) of a certain width is fitted on the front guide wheel (403) and the rear guide wheel (401-2). 4) On the front guide wheel (403), the belt (6) facing the bag opening (301) of the packaging bag crosses the bag opening guide seam (402) and twists 180 degrees backward from the rear guide wheel (404) to the rear of the front guide wheel (403). The twist 180 degrees makes the rotation direction of the front guide wheel (403) and the rear guide wheel (404) exactly opposite. The twist 180 degrees of the belt (6) crossing the bag opening guide seam (402) is a downward twist. The twist is such that the side of the belt width turns 180 degrees at the upper end of the bag opening guide seam (402) and is wrapped against the inner clamp plate (401-1) to the rear guide wheel (404). A motor (7) drives the front guide wheel (403) or the rear guide wheel (404) to rotate.

2. The front folding mechanism of the bag sewing machine according to claim 1, characterized in that, The rear guide wheel (404) is driven to rotate by the motor (7) and is called the driving wheel. The front guide wheel (403) is the driven wheel. The bottom axial end of the front guide wheel (403) is higher than or equal to the bag opening guide seam (402) on the side of the outer clamping plate (401-2), so that the width direction of the twisted belt is higher than the bag opening guide seam (402) on the outside of the bag opening guide seam (402). The upper axial end of the rear guide wheel (404) is higher than or level with the bag opening guide seam (402) on the side of the inner clamping plate (401-1), so that the upper end of the belt on the rear guide wheel (404) is flush with the bag opening guide seam (402).

3. The front folding mechanism of the bag sewing machine according to claim 1, characterized in that, The speed at which the motor (7) drives the belt to rotate is greater than or equal to the speed at which the conveyor belt (1) transports the packaging bag.

4. The front folding mechanism of the bag sewing machine according to claim 1, characterized in that, The distance between the front guide wheel (403) and the rear guide wheel (404) is such that the belt (6) is twisted and turned 180 degrees to face and adhere to the inner clamp plate (401-1) by a distance of not less than 200 mm.

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