Automatic knotting machine for plastic bags

Abstract

The present invention relates to an automatic knotting machine for plastic bags, comprising a workbench, a power mechanism, an arm connecting rod mechanism and a wrist replacement mechanism, wherein four arc grooves are provided at the corners of the workbench, and vertical sliding rods are symmetrically provided on both sides below the workbench; the power mechanism is provided below the workbench; the arm connecting rod mechanism is arranged in parallel on both sides of the workbench, and the arm connecting rod mechanism on each side comprises two symmetrically provided connecting rod members, the lower part of each connecting rod member is placed below the workbench and connected to the power mechanism, the middle part of the connecting rod member moves along the arc groove through a deflection rod, and the upper part of the connecting rod member is placed above the workbench and connected to a bracket; the bracket is provided between the two corresponding connecting rod members on both sides of the workbench, and the wrist replacement mechanism is provided on both brackets. The present invention has a reasonable structure and adopts mechanized operation, which can not only speed up the knotting speed and improve the efficiency, but also reduce the labor cost, and has good practicality.

Description

Technical Field

[0001] The invention relates to the technical field of plastic bag knotting, in particular to an automatic plastic bag knotting machine. Background Art

[0002] At present, most vegetable processing companies use plastic bags to pack vegetables. Take the carrot factory as an example. It automatically cleans and sorts the dug carrots, manually bags and packs them, and finally transports them to various supermarkets. The bagging and packing of carrots usually requires a lot of manpower to complete. After bagging, the plastic bag needs to be tied and tightened to seal it to prevent the carrots from falling. Traditional manual knotting is done manually, which is not only slow and inefficient, but also requires a lot of labor, is time-consuming and labor-intensive, and workers are prone to fatigue and other problems. In addition, the knotting quality is uneven. There is a risk of plastic bags opening during transportation, affecting the economic benefits of the factory.

[0003] The prior art mostly includes kelp knotting machines, automatic baling machines and other knotting devices, but lacks corresponding equipment for knotting plastic bags. Therefore, an automatic knotting machine for plastic bags is proposed. Summary of the invention

[0004] In order to solve the problem of high labor intensity and low efficiency in traditional manual plastic bag knotting, the present invention provides an automatic plastic bag knotting machine which can replace manual labor to automatically knot plastic bags efficiently.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is:

[0006] An automatic knotting machine for plastic bags comprises a workbench, a power mechanism, an arm connecting rod mechanism and a wrist replacement mechanism, wherein four arc grooves are provided at the corners of the workbench, and vertical sliding rods are symmetrically provided on both sides below the workbench;

[0007] The power mechanism is arranged below the workbench and is located between the slide bars on both sides;

[0008] The arm link mechanism is arranged in parallel on both sides of the workbench, and the arm link mechanism on each side includes two symmetrically arranged link members, the lower part of each link member is placed below the workbench and connected to the power mechanism, the middle part of the link member moves along the arc groove through the deflection rod, and the upper part of the link member is placed above the workbench and connected to a bracket;

[0009] The bracket is arranged between two corresponding connecting rods on both sides of the workbench, and the wrist replacement mechanism is arranged on the two brackets, and the two wrist replacement mechanisms are relatively distributed.

[0010] Furthermore, the power mechanism includes a motor frame arranged on the workbench, a transmission motor arranged on the motor frame, a gear shaft rotatably arranged between two slide bars, a crank arranged at both ends of the gear shaft, a connecting rod and a slider sliding up and down along the slide bar;

[0011] The transmission motor is geared to the gear shaft, both ends of the gear shaft pass through the slide bar to connect to the crank, the slide bar is sleeved on the slide bar, and both ends of the connecting rod are hinged to the crank and the slide bar.

[0012] Further, the two connecting rod members are staggeredly distributed, and each connecting rod member includes a large arm connecting rod, a large arm, a connecting arm, a small arm and a wrist connecting rod;

[0013] The middle part of the upper arm moves along the arc groove through the deflection rod, the lower part of the upper arm is connected to the slider through the upper arm connecting rod, the lower part of the connecting arm is hinged on the workbench, the upper part of the connecting arm passes through the upper arm and is hinged to the forearm, the upper part of the forearm passes through the upper arm, and the wrist connecting rod is arranged between the forearm and the upper arm.

[0014] Furthermore, the upper part of the upper arm is bent inward, and the upper arms of the two connecting rod members on one side of the workbench are distributed in an "×" shape after being bent. A limiting groove is opened on the upper part of the upper arm, and the cross-section of the connecting arm is in a "[" shape. The upper part of the connecting arm passes through the limiting groove, and the lower part of the forearm is placed in the connecting arm and is hinged to the bending part of the upper part of the connecting arm. The upper part of the forearm passes through the limiting groove and is connected to the wrist connecting rod.

[0015] Furthermore, tension springs are arranged between the upper part of the slide rod and the lower part of the upper arm, and between the upper part of the upper arm and the upper part of the connecting arm.

[0016] Furthermore, the bracket is arranged between the corresponding wrist connecting rods on both sides of the workbench, and the bracket includes a front frame and a rear frame, and the wrist replacement mechanism is arranged between the front frame and the rear frame.

[0017] Further, the wrist replacement mechanism includes a stepping motor, a shell cover, a replacement shell, a replacement disk and a replacement rod, the stepping motor is connected to the replacement shell through the shell cover, the replacement shell is a hollow cylindrical structure with openings at both ends, the replacement disk is rotatably arranged in the replacement shell, and the replacement disk is connected to the stepping motor;

[0018] The replacement rod is inserted at the edge of the replacement disk, and a hollow winding shaft for winding a handle of a plastic bag is elastically connected to the middle of the replacement disk.

[0019] Furthermore, a latch tongue and a slot notch are symmetrically arranged at one end of the replacement shell, and the latch tongues and slot notches on the replacement shells of the wrist replacement mechanisms on both sides are staggered, and the latch tongue is elastically connected to the replacement shell;

[0020] The replacement disk is provided with a plurality of blind holes for inserting the replacement rods in an annular direction, wherein two of the blind holes correspond to the positions of the tongue and the slot notch respectively, and the replacement rods for hooking the handles of the plastic bag are inserted into the blind holes corresponding to the positions of the tongues; the replacement rods of the wrist replacement mechanisms on both sides are staggeredly distributed.

[0021] Furthermore, the displacement rod is a cylindrical structure with variable diameter, the diameter of the middle part of the displacement rod is smaller than the diameter of the two ends, buckles are respectively provided on the circumferential surfaces of the two ends of the displacement rod, one end of the displacement rod is placed in the blind hole and is engaged with the tongue through the buckle, and the other end of the displacement rod extends out of the blind hole.

[0022] Through the above technical solution, the beneficial effects of the present invention are:

[0023] The invention has a reasonable structural design and realizes automatic knotting of plastic bags by combining a mechanical motion mechanism with single-chip computer control, thereby overcoming the shortcomings of the existing manual knotting method of plastic bags, which is slow, inefficient, time-consuming and labor-intensive. The mechanical part of the invention is mainly composed of a workbench, a power mechanism, an arm connecting rod mechanism and a wrist replacement mechanism.

[0024] The power mechanism provided in the present invention can provide power for the entire knotting action; the arm connecting rod mechanism provided can tighten the knot formed by the handle of the plastic bag, and is driven by the gear and crank slider mechanism. When the second knot is tied, the handle of the plastic bag will become shorter. In order to enable the crank of the power mechanism to still rotate a full circle, a tension spring is used to constrain the rotation of the upper arm, thereby ensuring that the knotting machine can work continuously and improving the knotting efficiency; the wrist replacement mechanism uses the mutual rotation cooperation of the buckle of the replacement rod and the incomplete slot notch of the replacement shell to realize the replacement action of the two handles of the plastic bag.

[0025] The present invention can perform mechanized continuous operation and has the advantages of high knotting efficiency, firm knotting, time and labor saving, and strong operating stability. It can replace manual labor for tying plastic bags in factories or other occasions where plastic bags are used for a long time, thereby reducing manual labor and labor costs and having good practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The utility model is a schematic diagram of the overall structure of an automatic knotting machine for plastic bags of the present invention.

[0027] Figure 2 The invention discloses an automatic plastic bag knotting machine. Figure 1 Top view of the .

[0028] Figure 3 The invention discloses a schematic diagram of an arm connecting rod mechanism of an automatic plastic bag knotting machine.

[0029] Figure 4 The invention discloses a schematic diagram of a wrist replacement mechanism of an automatic plastic bag knotting machine.

[0030] Figure 5 The utility model is an exploded view of a wrist replacement mechanism of an automatic knotting machine for plastic bags according to the present invention.

[0031] Figure 6 The utility model is a cross-sectional view of a wrist replacement mechanism of an automatic knotting machine for plastic bags according to the present invention.

[0032] Figure 7 It is a schematic diagram of step 1 in an embodiment of an automatic knotting machine for plastic bags of the present invention.

[0033] Figure 8 The invention discloses an automatic plastic bag knotting machine. Figure 7 An enlarged schematic diagram of .

[0034] Fig. 9 It is a schematic diagram of step 2 in an embodiment of an automatic knotting machine for plastic bags of the present invention.

[0035] Fig.10 The invention discloses an automatic plastic bag knotting machine. Fig. 9 A-axis enlarged diagram of the handle hook.

[0036] Fig.11 It is an enlarged schematic diagram of a single annular hole in step 3 in an embodiment of an automatic knotting machine for plastic bags of the present invention.

[0037] Fig.12 It is a schematic diagram of step 4 in an embodiment of an automatic knotting machine for plastic bags of the present invention.

[0038] Fig.13 The invention discloses an automatic plastic bag knotting machine. Fig.12 Cross-sectional view of the replacement rods on both sides.

[0039] Fig.14 It is a schematic diagram of step 5 in an embodiment of an automatic knotting machine for plastic bags of the present invention.

[0040] Fig.15 It is one of the schematic diagrams of step 6 in an embodiment of an automatic knotting machine for plastic bags of the present invention.

[0041] Fig.16 This is the second schematic diagram of step 6 in an embodiment of an automatic knotting machine for plastic bags of the present invention.

[0042] Fig.17 It is one of the schematic diagrams of step 7 in an embodiment of an automatic knotting machine for plastic bags of the present invention.

[0043] Fig.18 This is the second schematic diagram of step 7 in an embodiment of an automatic knotting machine for plastic bags of the present invention.

[0044] Fig.19 It is one of the schematic diagrams of step 8 in an embodiment of an automatic knotting machine for plastic bags of the present invention.

[0045] Fig. 20 This is the second schematic diagram of step 8 in an embodiment of an automatic knotting machine for plastic bags of the present invention.

[0046] Fig.21 This is the third schematic diagram of step 8 in an embodiment of an automatic knotting machine for plastic bags of the present invention.

[0047] Fig. 22 This is the fourth schematic diagram of step 8 in an embodiment of an automatic knotting machine for plastic bags of the present invention.

[0048] Fig.23 It is a schematic diagram of step 9 in an embodiment of an automatic knotting machine for plastic bags of the present invention.

[0049] The numbers in the accompanying drawings are: 1 is a workbench, 2 is an arc groove, 3 is a slide rod, 4 is a deflection rod, 501 is a motor frame, 502 is a transmission motor, 503 is a gear shaft, 504 is a crank, 505 is a connecting rod, 506 is a slider, 601 is a large arm connecting rod, 602 is a large arm, 603 is a connecting arm, 604 is a small arm, 605 is a wrist connecting rod, 7 is a tension spring, 801 is a front frame, 802 is a rear frame, 901 is a stepping motor, 902 is a shell cover, 903 is a replacement shell, 904 is a replacement disk, 905 is a replacement rod, 10 is a winding shaft, 11 is a tongue, 12 is a slot notch, 13 is a blind hole, and 14 is a buckle. DETAILED DESCRIPTION

[0050] The specific implementation of the present invention is described in detail below with reference to the accompanying drawings:

[0051] like Figure 1 to Figure 23 As shown, an automatic knotting machine for plastic bags comprises a workbench 1, a power mechanism, an arm connecting rod mechanism and a wrist replacement mechanism. Four arc grooves 2 are provided at the corners of the workbench 1. Vertical sliding rods 3 are symmetrically provided on both sides below the workbench 1. The sliding rods 3 are square rods.

[0052] The power mechanism is arranged below the workbench 1 and is located between the slide bars 3 on both sides;

[0053] The arm link mechanism is arranged in parallel on both sides of the workbench 1, and the arm link mechanism on each side includes two symmetrically arranged link members, the lower part of each link member is placed below the workbench 1 and connected to the power mechanism, a deflection rod 4 is arranged in the middle of the link member, the link member moves along the arc groove 2 through the deflection rod 4, and the upper part of the link member is placed above the workbench 1 and connected to a bracket;

[0054] The bracket is arranged between two corresponding connecting rods on both sides of the workbench 1, and the wrist replacement mechanism is arranged on both brackets, and the two wrist replacement mechanisms are relatively distributed.

[0055] In this embodiment, the power mechanism includes a motor frame 501 arranged on the workbench 1, a transmission motor 502 arranged on the motor frame 501, a gear shaft 503 rotatably arranged between two slide bars 3, a crank 504 arranged at both ends of the gear shaft 503, a connecting rod 505 and a slider 506 sliding up and down along the slide bar 3;

[0056] The motor frame 501 is arranged in the middle part below the workbench 1, the transmission motor 502 is gear-driven with the gear shaft 503, and the two ends of the gear shaft 503 pass through the sliding rod 3 to connect the crank 504. Specifically, the crank 504 is assembled on the two ends of the gear shaft 503 through square holes; the slider 506 is sleeved on the sliding rod 3, and the two ends of the connecting rod 505 are respectively hinged to the crank 504 and the slider 506, and the coordinated movement of the crank 504, the connecting rod 505 and the slider 506 constitutes a crank 504 slider 506 mechanism.

[0057] In this embodiment, Figure 3 As shown, the two connecting rod members are staggered, and each of the connecting rod members includes an upper arm connecting rod 601, an upper arm 602, a connecting arm 603, a small arm 604 and a wrist connecting rod 605. The middle part of the upper arm 602 moves along the arc groove 2 through the deflection rod 4, and can also swing in a circular direction with the deflection rod 4 as the axis. The lower part of the upper arm 602 is connected to the slider 506 through the upper arm connecting rod 601, and the lower part of the connecting arm 603 is hinged on the workbench 1. The upper part of the connecting arm 603 passes through the upper arm 602 and is hinged to the small arm 604. The upper part of the small arm 604 passes through the upper arm 602, and the wrist connecting rod 605 is hinged between the small arm 604 and the upper arm 602.

[0058] Specifically, the upper part of the upper arm 602 is bent inward, and the upper arms 602 of the two connecting rods on one side of the workbench 1 are distributed in an "X" shape after being bent. A limiting groove is provided on the upper part of the upper arm 602, and the cross-section of the connecting arm 603 is in a "[" shape. The upper part of the connecting arm 603 passes through the limiting groove, and the lower bending part of the connecting arm 603 is hinged on the workbench 1. The bending parts at the upper and lower ends of the connecting arm 603 form a limit, and the upper end thereof can limit the swing range of the small arm 604, and the lower end thereof is limited by the workbench 1 to control the swing of the connecting arm 603;

[0059] The lower part of the small arm 604 is placed in the connecting arm 603 and is hinged to the bending part of the upper part of the connecting arm 603 . The upper part of the small arm 604 passes through the limiting groove and is connected to the wrist connecting rod 605 .

[0060] In order to ensure that the deflection rod 4 in the middle of the upper arm 602 can be placed in the arc groove 2 to slide when the plastic bag handle is tightened, a tension spring 7 is provided between the upper part of the slide rod 3 and the lower part of the upper arm 602, and between the upper part of the upper arm 602 and the upper part of the connecting arm 603. Specifically, the tension spring 7 between the upper part of the slide rod 3 and the lower part of the upper arm 602 can provide tension for the upper arm 602, and the tension spring 7 between the upper part of the upper arm 602 and the upper part of the connecting arm 603 can provide tension for the connecting arm 603;

[0061] Since the handle of the plastic bag will become shorter when the second knot is tied on the plastic bag, the tension spring 7 constrains the upper arm 602 and the connecting arm 603. Under the premise that the handle of the plastic bag is not broken, the crank 504, the connecting rod 505 and the slider 506 forming the crank 504 and the slider 506 mechanism can rotate a full circle, so that the knotting function can work continuously to improve the knotting efficiency.

[0062] In this embodiment, the mutual limitation of the workbench 1, the upper arm 602, the connecting arm 603, the lower arm 604 and the wrist connecting rod 605, and the transmission of the gear and the crank 504 slider 506 mechanism can realize the mutual conversion of the parallelogram mechanism and the anti-parallelogram mechanism, thereby realizing the subsequent displacement of the displacement rod 905 and the tilting and stretching of the plastic bag handle, which greatly simplifies the working steps and improves the knotting efficiency.

[0063] In this embodiment, the bracket is arranged between the corresponding wrist connecting rods 605 on both sides of the workbench 1, and the bracket includes a front frame 801 and a rear frame 802. The wrist replacement mechanism is arranged between the front frame 801 and the rear frame 802.

[0064] Specifically, Figures 4 to 6 As shown, the wrist replacement mechanism includes a stepping motor 901, a shell cover 902, a replacement shell 903, a replacement disk 904 and a replacement rod 905. The rear frame 802 is buckled on the stepping motor 901, and the stepping motor 901 is connected to the replacement shell 903 through the shell cover 902. The front frame 801 is buckled on the replacement shell 903. The replacement shell 903 is a hollow cylindrical structure with two ends open. An inner flange is provided at one end of the replacement shell 903. The replacement disk 904 is rotatably arranged in the replacement shell 903. The replacement disk 904 is connected to the stepping motor 901. The replacement disk 904 is restricted by the inner flange and the shell cover 902 to avoid axial movement.

[0065] The replacement rod 905 is inserted at the edge of the replacement disk 904, and a hollow winding shaft 10 for winding and sealing one end of a plastic bag handle is elastically connected to the middle of the replacement disk 904. Specifically, the replacement disk 904 is elastically connected to the winding shaft 10 through a spring, and it can be extended and retracted in the replacement disk 904. When working, after the two winding shafts 10 of the wrist replacement mechanisms on both sides come into contact, they each shrink into their respective replacement disks 904, so that the upper arm 602 continues to close, thereby allowing the replacement rod 905 to complete the replacement action.

[0066] Specifically, a latch tongue 11 and a slot notch 12 are symmetrically arranged on the inner turning edge of one end of the replacement shell 903, and the latch tongues 11 and the slot notches 12 on the replacement shells 903 of the wrist replacement mechanisms on both sides are staggered, and the latch tongue 11 is elastically connected to the replacement shell 903 through a spring;

[0067] Ten blind holes 13 for inserting the replacement rod 905 are circumferentially provided on the replacement disk 904, wherein two of the blind holes 13 correspond to the positions of the latch tongue 11 and the slot notch 12 respectively, and the replacement rod 905 for hooking the plastic bag handle is inserted into the blind hole 13 corresponding to the position of the latch tongue 11; with the center of the replacement disk 904 as the center of the circle and the radius from the center of the replacement disk 904 to the center of the blind hole 13, the central angle α formed by the line connecting the centers of two adjacent blind holes 13 is 36°.

[0068] Correspondingly, the displacement rods 905 of the wrist displacement mechanisms on both sides are staggered. Specifically, the displacement rods 905 are cylindrical structures with variable diameters. The diameter of the middle part of the displacement rods 905 is smaller than the diameter of the two ends. Buckles 14 are respectively provided on the circumferential surfaces of the two ends of the displacement rods 905. The size of the buckles 14 is the same as the size of the slot notch 12. The slot notch 12 can make the displacement rod 905 detach from here to achieve the displacement action.

[0069] One end of the displacement rod 905 is placed in the blind hole 13 and is engaged with the latch tongue 11 through the buckle 14, and the other end of the displacement rod 905 extends out of the blind hole 13. The displacement rod 905 placed in the blind hole 13 can perform circular motion following the rotation of the displacement disk 904, so that the plastic bag handle is wound around the winding shaft 10 to form an annular hole.

[0070] Through the mutual cooperation of the various components of the wrist replacement mechanism, the replacement disk 904 rotates once, and the connecting rods on both sides are closed toward each other once, which can automatically realize the actions of constraining the replacement rod 905, releasing the constraint of the replacement rod 905, etc., thereby completing a replacement action, greatly simplifying the working steps, improving the knotting efficiency, and also reducing the requirements for the complexity of the subsequent transmission and control system.

[0071] In this embodiment, an STM32 single chip microcomputer is also provided, which controls the transmission motor 502 and the two stepper motors 901 so that they rotate intermittently with each other, thereby driving the various parts of the knotting machine to cooperate with each other and move continuously, finally realizing the knotting action and improving the knotting efficiency.

[0072] When the present invention performs knotting operation on a plastic bag, the steps are as follows:

[0073] Step 1. Hang the plastic bag: Figure 7-8 As shown, the two handles of the plastic bag are manually hooked on the middle position of the displacement rod 905 of the wrist displacement mechanism on both sides, and two sections of rope are used to replace the two handles of the plastic bag;

[0074] Step 2. The displacement rod 905 moves to a horizontal position: the transmission motor 502 is started, and then the gear shaft 503 rotates to drive the crank 504 to rotate counterclockwise, and the slider 506 moves down along the slide bar 3. The slider 506 drives the upper arm 602 to swing through the upper arm connecting rod 601 to close the upper arm 602. The limit at the lower end of the connecting arm 603 is always close to the workbench 1. At this time, the arm connecting rod mechanism is equivalent to an anti-parallelogram mechanism. When the upper arm 602 is closed, the wrist connecting rod 605 will tend to be horizontal. When the forearm 604 contacts the upper end limit of the connecting arm 603, the wrist connecting rod 605 is just horizontal. Figures 9-10 As shown, at this time, the displacement rod 905 remains in a horizontal state, the transmission motor 502 is turned off, and the upper arm 602 stops closing;

[0075] Step 3. The handle forms an annular hole at one time: the stepper motors 901 on both sides are started at the same time and rotate in opposite directions, so that the two replacement plates 904 and their respective replacement rods 905 rotate 324° in opposite directions, thereby driving the left and right handles to rotate 324° in opposite directions. Since the two replacement rods 905 need to stagger the position of a blind hole 13 for replacement, the single chip microcomputer controls the stepper motor 901 to rotate 324°;

[0076] After the rotation, the two handles are respectively wound around their respective winding shafts 10 to form two annular holes, such as Fig.11 As shown, at this time, the position of the replacement rod 905 on one side is just rotated to the position of the slot notch 12 on the other side, preparing for the subsequent replacement action. Since the upper arm 602 is in an inwardly closed state at this time, the replacement rod 905 will not fall off;

[0077] Step 4. Replace the handles: After the two handles form an annular hole, the two stepper motors 901 are turned off, and the transmission motor 502 is started again to make the upper arm 602 continue to close. Since the lower arm 604 contacts the upper limit of the connecting arm 603, the connecting arm 603 will swing together with the lower arm 604. At this time, the distance between the lower end hinge of the connecting arm 603 and the upper end hinge of the lower arm 604 is equal to the distance between the two hinges of the upper half of the upper arm 602, thereby forming a parallelogram mechanism, such as Fig.12 As shown by the middle dotted line, when the upper arm 602 is closed, the two wrist connecting rods 605 are translated toward each other;

[0078] The wrist connecting rod 605 translates toward each other, and then the two winding shafts 10 translate toward each other until the end faces contact, and the winding shafts 10 are forced to retract into their respective replacement disks 904, so that the large arm 602 continues to close, so that the two replacement rods 905 are respectively inserted into the blind holes 13 of the opposite replacement disks 904 through the slot notches 12. When the replacement rod 905 is inserted into the blind hole 13 of the replacement disk 904, the tongue 11 on the inner flange of the replacement shell 903 will clamp the buckle 14 of the replacement rod 905 to ensure that the replacement rod 905 is fixed. Fig.13 As shown, at this time, the slider 506 just slides to the lower limit position;

[0079] Step 5. Winding the handle: After the latch 11 fastens the replacement rod 905 in the blind hole 13 of the replacement plate 904 through the latch 14, the transmission motor 502 continues to rotate, and the crank 504 and the connecting rod 505 pass through the straightened collinear position, so that the slider 506 slides upward, thereby opening the upper arm 602;

[0080] Under the action of the tension spring 7, the small arm 604 is still close to the upper end limit of the connecting arm 603, and at this time it is still the parallelogram mechanism formed above, so the two wrist replacement mechanisms will simultaneously translate relative to each other and then separate, and at the same time, the separation will pull the opposite replacement rod 905 to move, thereby pulling the right handle into the annular hole formed by the left handle, as shown in FIG. Fig.14 As shown, similarly, pull the left handle into the annular hole formed by the right handle to complete the winding action of the handle;

[0081] Step 6. Tighten the handle: the transmission motor 502 continues to drive the slider 506 to slide upward, so that the upper arm 602 continues to open. When the upper arm 602 opens, the winding shaft 10 will pop out under the action of the spring to prepare for the next winding of the handle;

[0082] When the lower end of the connecting arm 603 contacts the workbench 1, the connecting arm 603 stops swinging, and the small arm 604 starts to swing around the hinge of the upper end of the connecting arm 603, forming an anti-parallelogram mechanism. As shown in the figure, while the wrist link 605 moves outward, it will swing upward and tend to be vertical. Fig.15As shown by the dotted line, a knot is formed when the two handles are tightened, and the transmission motor 502 continues to open the upper arm 602, so that the knot is gradually tightened. Fig.16 As shown;

[0083] Step 7. Transition stage: When the knot is tightened, the upper hinge of the upper arm 602 is fixed under the pulling force of the plastic bag handle. Since the transmission motor 502 continues to drive the slider 506 to slide upward, the deflection rod 4 in the middle of the upper arm 602 will slide upward along the arc groove 2. At this time, the arm connecting rod mechanism is equivalent to the swing rod mechanism of the slider 506, until the crank 504 and the connecting rod 505 reach the overlapping collinear position, that is, when the slider 506 reaches the upper limit position, the deflection rod 4 in the middle of the upper arm 602 slides upward to the highest point, as shown in FIG. Fig.17 As shown;

[0084] At this time, the transmission motor 502 continues to drive the crank 504 to rotate, causing the slider 506 to slide downward. Under the action of the tension spring 7, the deflection rod 4 in the middle of the large arm 602 slides downward in the arc groove 2 until it reaches the limit position. After reaching the limit position, the arm connecting rod mechanism at this time is equivalent to an anti-parallelogram mechanism, such as Fig.18 As shown, the upper arm 602 drives the wrist replacement mechanisms on both sides to close, and the wrist replacement mechanisms drive the plastic bag handles to close and swing downward to be horizontal;

[0085] Step 8. The handle forms a circular hole for the second time: When the small arm 604 contacts the upper limit of the connecting arm 603, the wrist replacement mechanism is just horizontal. At this time, the arm connecting rod mechanism is equivalent to a parallelogram mechanism. Turn off the transmission motor 502, and repeat steps 3-6 to form a circular hole, replace the handle, wrap the handle, and tighten the handle to perform the second knot action, such as Figures 19 to 22 As shown, no further details will be given here;

[0086] Step 9. Remove the plastic bag: When the second knot is tightened and the deflection rod 4 in the middle of the upper arm 602 returns to its original position, the plastic bag handle is tied with two knots, such as Fig.23 As shown, turn off the transmission motor 5023, stop the upper arm 602 from closing, remove the plastic bag from the knotting machine replacement rod 905, and the knotting work of a plastic bag can be completed.

[0087] The embodiments described above are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. Therefore, any equivalent changes or modifications made according to the structures, features and principles described in the patent scope of the present invention should be included in the scope of the patent application of the present invention.

Claims

1. A plastic bag automatic knotting machine, characterized in that: It comprises a workbench (1), a power mechanism, an arm connecting rod mechanism and a wrist replacement mechanism, wherein four arc grooves (2) are provided at the corners of the workbench (1), and vertical sliding rods (3) are symmetrically provided on both sides below the workbench (1); The power mechanism is arranged below the workbench (1), and is located between the slide bars (3) on both sides; the power mechanism comprises a motor frame (501) arranged on the workbench (1), a transmission motor (502) arranged on the motor frame (501), a gear shaft (503) rotatably arranged between the two slide bars (3), cranks (504) arranged at both ends of the gear shaft (503), a connecting rod (505), and a slider (506) sliding up and down along the slide bar (3); The arm connecting rod mechanism is arranged in parallel on both sides of the workbench (1), and the arm connecting rod mechanism on each side comprises two connecting rod members arranged symmetrically, the two connecting rod members are staggered, the lower part of each connecting rod member is placed below the workbench (1) and connected to the power mechanism, the middle part of the connecting rod member moves along the circular arc groove (2) through the deflection rod (4), and the upper part of the connecting rod member is placed above the workbench (1) and connected to a bracket; Each of the connecting rod members comprises an upper arm connecting rod (601), an upper arm (602), a connecting arm (603), a small arm (604) and a wrist connecting rod (605); the middle portion of the upper arm (602) moves along the arc groove (2) via the deflection rod (4); the lower portion of the upper arm (602) is connected to the slider (506) via the upper arm connecting rod (601); the lower portion of the connecting arm (603) is hinged on the workbench (1); the upper portion of the connecting arm (603) passes through the upper arm (602) and is hinged to the small arm (604); the upper portion of the small arm (604) passes through the upper arm (602); and the wrist connecting rod (605) is arranged between the small arm (604) and the upper arm (602); The upper part of the upper arm (602) is bent inwards, and the upper arms (602) of the two connecting rods on one side of the workbench (1) are distributed in an "X" shape after being bent. A limiting groove is provided on the upper part of the upper arm (602). The cross section of the connecting arm (603) is in a "[" shape. The upper part of the connecting arm (603) passes through the limiting groove. The lower part of the small arm (604) is placed in the connecting arm (603) and is hinged to the bending part of the upper part of the connecting arm (603). The upper part of the small arm (604) passes through the limiting groove and is connected to the wrist connecting rod (605); The bracket is arranged between two corresponding connecting rods on both sides of the workbench (1), and the wrist replacement mechanism is arranged on the two brackets. The two wrist replacement mechanisms are arranged relatively to each other, and the wrist replacement mechanism comprises a stepping motor (901), a shell cover (902), a replacement shell (903), a replacement disk (904) and a replacement rod (905); The stepper motor (901) is connected to the replacement shell (903) via the shell cover (902); the replacement shell (903) is a hollow cylindrical structure with openings at both ends; the replacement disk (904) is rotatably arranged in the replacement shell (903); the replacement disk (904) is connected to the stepper motor (901); the replacement rod (905) is inserted at the edge of the replacement disk (904); and a hollow winding shaft (10) for winding a plastic bag handle is elastically connected to the middle of the replacement disk (904); A latch tongue (11) and a latch slot (12) are symmetrically arranged at one end of the replacement shell (903); the latch tongues (11) and the latch slots (12) on the replacement shells (903) of the wrist replacement mechanisms on both sides are arranged in an alternating manner; and the latch tongues (11) are elastically connected to the replacement shell (903); The replacement disk (904) is provided with a plurality of blind holes (13) for inserting the replacement rods (905) in a circular direction, wherein two of the blind holes (13) correspond to the positions of the latch tongue (11) and the latch slot notch (12), respectively, and the replacement rod (905) for hooking the plastic bag handle is inserted into the blind hole (13) corresponding to the position of the latch tongue (11); the replacement rods (905) of the wrist replacement mechanisms on both sides are staggeredly distributed; The displacement rod (905) is a cylindrical structure with a variable diameter. The diameter of the middle portion of the displacement rod (905) is smaller than the diameter of the two ends. Buckles (14) are respectively provided on the circumferential surfaces of the two ends of the displacement rod (905). One end of the displacement rod (905) is placed in the blind hole (13) and is engaged with the latch tongue (11) through the buckle (14). The other end of the displacement rod (905) extends out of the blind hole (13).

2. The automatic plastic bag knotting machine according to claim 1, characterized in that: The transmission motor (502) and the gear shaft (503) are gear-driven, and two ends of the gear shaft (503) respectively pass through the slide bar (3) to connect to the crank (504), the slide bar (506) is sleeved on the slide bar (3), and two ends of the connecting rod (505) are respectively hinged to the crank (504) and the slide bar (506).

3. The automatic plastic bag knotting machine according to claim 1, characterized in that: Tension springs (7) are provided between the upper portion of the slide bar (3) and the lower portion of the upper arm (602), and between the upper portion of the upper arm (602) and the upper portion of the connecting arm (603).

4. The automatic plastic bag knotting machine according to claim 1, characterized in that: The bracket is arranged between the corresponding wrist connecting rods (605) on both sides of the workbench (1), and the bracket comprises a front frame (801) and a rear frame (802), and the wrist replacement mechanism is arranged between the front frame (801) and the rear frame (802).

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