Pipe drawing, welding and forming integrated manufacturing process for plastic bucket

Abstract

The invention discloses a pipe drawing and welding forming integrated manufacturing process for a plastic bucket. The process comprises the following steps that S1, a pipe drawing blank is prepared, specifically, a continuous plastic pipe is extruded through pipe drawing equipment; s2, a fixed-length cutting process: conveying the continuous plastic pipe extruded by the pipe drawing equipment to cutting equipment; s3, workpiece positioning and clamping are conducted, specifically, the cut barrel body blank, a preset base and a barrel cover are transferred to welding equipment; s4, inner side support arrangement; and S5, heating welding forming: passing through a heating structure of welding equipment. The problems that a traditional blow molding process is low in efficiency, uneven in barrel body wall thickness, high in mold cost, difficult in model changing and high in material loss and energy consumption are solved; through the modes of extrusion molding, fixed-length cutting and hot melting welding, efficient continuous production is achieved, it is guaranteed that the wall thickness of the barrel body is uniform, the structural strength is stable, no complex mold is needed, production of products of various specifications can be rapidly adapted, the production cost is remarkably reduced, and the device is especially suitable for large-size containers.

Description

Technical Field

[0001] This invention relates to the field of plastic bucket tubing welding technology, and in particular to an integrated manufacturing process for plastic bucket tubing tubing welding and forming. Background Technology

[0002] Plastic drums are a common storage and transportation container in various industries such as chemical storage and transportation, food and pharmaceuticals, and agriculture and animal husbandry, and their demand continues to grow. In particular, large-capacity, regular cylindrical products such as 200L round drums are widely used in industrial production. Traditional plastic drum manufacturing mostly uses blow molding, which involves blowing a molten preform and bonding it to a split mold to form the drum. This process requires a high-pressure inflation system and has many limitations.

[0003] The blow molding process is intermittent and inefficient. Furthermore, variations in gas pressure uniformity can lead to inconsistent barrel wall thickness, resulting in unstable structural strength and limited pressure resistance. Additionally, its complex mold structure results in high manufacturing costs, difficult mold changeovers, and an inability to adapt to the rapid switching demands of diverse product specifications. Moreover, it generates significant material waste and energy consumption, contradicting the trend towards green production.

[0004] As market demand for plastic bucket capacity continues to expand, and requirements for product quality, production efficiency, cost control, and environmental performance increase, traditional blow molding processes can no longer meet practical application needs.

[0005] Against this backdrop, this application proposes an integrated manufacturing process for plastic buckets by drawing and welding tubing. This process involves extruding tubular blanks, cutting them to a fixed length, and then hot-melting them with the bottom and lid of the bucket to manufacture plastic buckets. This effectively solves the drawbacks of the blow molding process. Therefore, there is an urgent need for a plastic bucket drawing and welding device adapted to this process to achieve efficient, high-quality, and low-cost large-capacity plastic bucket mass production. Summary of the Invention

[0006] The purpose of this invention is to solve the above-mentioned technical problems by proposing an integrated manufacturing process for plastic bucket tubing drawing, welding, and forming.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A manufacturing process for an integrated plastic bucket tubing assembly by tubing welding includes the following steps:

[0009] S1. Preparation of pipe drawing blank: Continuous plastic pipes are extruded through pipe drawing equipment to provide qualified blanks for the molding of plastic bucket bodies;

[0010] S2. Fixed-length cutting process: The continuous plastic tube extruded by the tube drawing equipment is conveyed to the cutting equipment, and the continuous plastic tube is precisely cut to a fixed length to obtain a barrel blank with uniform specifications.

[0011] S3. Workpiece positioning and clamping: The cut barrel blank, the preset base and the barrel lid are transferred to the welding equipment, and the three are coaxially positioned and clamped by the clamping structure of the welding equipment.

[0012] S4. Inner support arrangement: Insert the annular support structure in the contracted state in the welding equipment into the internal channel of the barrel blank from one end. Then control the radial expansion of the support structure to form an annular support surface that matches the inner side of the barrel, and support the inner mating parts of the barrel blank, base and barrel cover.

[0013] S5. Heating and welding: The welding equipment's heating structure is used to weld the mating surfaces of the coaxially positioned and internally supported barrel blank, base, and barrel lid, completing the overall welding and forming of the plastic barrel.

[0014] Preferably, the pipe drawing equipment is a high-precision extruder equipped with a fully automatic vacuum sizing box and a multi-track synchronous traction mechanism; the plastic raw material is selected from HDPE or PP thermoplastic plastic, which is dried in an 80-120℃ drying oven for 2-4 hours before use, and the moisture content is controlled at ≤0.1%; the heating temperature of the pipe drawing equipment is 180-230℃ for HDPE and 160-220℃ for PP, and the extrusion speed is 0.5-5m / min.

[0015] Preferably, the first clamping part includes a bracket and a support base disposed on the processing table. Two driving components are mounted on the bracket. The output end of the driving component is fixed with a first clamping plate and abuts against the plastic tube. A second clamping plate is fixed on the support base. The second clamping plate is used to support the bottom of the plastic tube.

[0016] Preferably, the second clamping part includes a first movable plate, an installation tube is fixed on the first movable plate, a first clamp is fixed on the installation tube, and the bucket lid is limited and installed in the first clamp.

[0017] Preferably, the third clamping part includes a second movable plate, a support column is mounted on the second movable plate, a second clamping sleeve is fixed on the support column, the second clamping sleeve is coaxially arranged with the first clamping sleeve, and the base is limited within the second clamping sleeve.

[0018] Preferably, the heating structure includes a movable frame that is set on a processing table, and two heating rings are installed on the movable frame. The heating rings have notches, and a heating arc block is movably connected in the notches.

[0019] Preferably, the support structure further includes a conveying section that passes through the installation pipe, the conveying section being equipped with four support rings, and the support rings being provided with two first short pipes and two second short pipes that communicate with the conveying section;

[0020] A first piston cylinder is fixed on the first short tube, a first movable piston slides inside the first piston cylinder, a first spring is fixed on the first movable piston and the first piston cylinder, a first pull rod is fixed on the first movable piston, and a first arc-shaped plate is fixed on the first pull rod.

[0021] A second piston cylinder is fixed on the second short tube, a second movable piston is slidably connected inside the second piston cylinder, a second spring is fixed on the second movable piston and the second piston cylinder, a second pull rod is fixed on the second movable piston, and a second arc-shaped plate is fixed on the second pull rod;

[0022] The elastic force of the first spring is less than that of the second spring.

[0023] Preferably, when the two first arc-shaped plates and the two second arc-shaped plates abut against each other, the two first arc-shaped plates and the two second arc-shaped plates form a ring, and the abutting contact is locked by the locking part.

[0024] Preferably, the locking part includes two first mating openings disposed on the inner sides of both ends of the first arc-shaped plate, and two second mating openings disposed on the outer sides of both ends of the second arc-shaped plate. A locking block is fixed on the first arc-shaped plate and located at the first mating opening; a lock hole is disposed on the second arc-shaped plate and located at the second mating opening; when the first arc-shaped plate and the two second arc-shaped plates abut against each other, the first mating openings and the second mating openings are engaged, and the locking block is engaged into the lock hole.

[0025] Preferably, a power unit is installed on the processing table, and the output end of the power unit is connected to a fluid pipe, which is connected to the mounting pipe through a rotary joint.

[0026] Compared with the prior art, the beneficial effects of this invention are as follows:

[0027] 1. The extrusion speed of the tube drawing equipment can reach several meters per minute, realizing continuous production; the cutting equipment has a synchronous control function that matches the extrusion speed of the tube drawing equipment, and can quickly complete fixed-length cutting; the components of the welding equipment work together to quickly complete the welding of plastic buckets. The overall production process is continuous and efficient, overcoming the drawbacks of intermittent and inefficient blow molding process.

[0028] 2. The structure can be changed to match the corresponding structure for large-capacity cylindrical barrels of different sizes. Unlike molds, it does not require separate mold making. It can quickly adapt to the production needs of diverse product specifications and solve the problem of difficult shape change in blow molding process.

[0029] 3. During the welding process, the supporting structure provides uniform support to the plastic tube, base, and inner side of the lid, preventing deformation during heating and extrusion, ensuring a neat weld surface, and making the welded plastic bucket structurally strong and pressure-bearing capacity more stable. This overcomes the shortcomings of blow molding process, such as the tendency for differences in bucket wall thickness and unstable structural strength.

[0030] In summary, this invention solves the problems of low efficiency, uneven barrel wall thickness, high mold cost, difficult mold changeover, material loss, and high energy consumption in traditional blow molding processes. By using extrusion molding, cutting to fixed length, and hot-melt welding, it achieves efficient and continuous production, ensuring uniform barrel wall thickness and stable structural strength. It also eliminates the need for complex molds, allowing for rapid adaptation to the production of diverse product specifications, significantly reducing production costs, and is especially suitable for large-size containers. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the integrated manufacturing process for drawing and welding plastic buckets according to the present invention.

[0032] Figure 2 This is a schematic diagram of the welding equipment used in the integrated manufacturing process of plastic bucket tubing drawing and welding proposed in this invention.

[0033] Figure 3 This is a front view of the welding equipment in the integrated manufacturing process of plastic bucket tube drawing and welding proposed in this invention;

[0034] Figure 4 This is a schematic diagram of the structure after the plastic tube is removed in the integrated manufacturing process of plastic bucket tube drawing and welding proposed in this invention;

[0035] Figure 5 This is a schematic diagram of the base and lid in an integrated manufacturing process for plastic bucket tubing welding and forming proposed in this invention.

[0036] Figure 6 This is a schematic diagram of the heating ring structure in the integrated manufacturing process of plastic bucket tube drawing and welding proposed in this invention;

[0037] Figure 7 This is a schematic diagram of the structure of the first arc plate and the second arc plate in the integrated manufacturing process of plastic bucket tube drawing and welding proposed in this invention;

[0038] Figure 8 This is a cross-sectional structural schematic diagram of the first piston cylinder and the second piston cylinder in an integrated manufacturing process for plastic bucket tubing welding and forming proposed in this invention.

[0039] Figure 9 This is a cross-sectional structural diagram of the conveying section in an integrated manufacturing process for plastic bucket tubing welding and forming proposed in this invention.

[0040] In the diagram: 1. Pipe pulling equipment; 2. Cutting equipment; 3. Welding equipment; 4. Processing table; 5. Heating ring; 6. Moving seat; 7. First moving plate; 8. Second moving plate; 9. Bracket; 10. Driving component; 11. First clamping plate; 12. Support seat; 13. Power unit; 14. Fluid pipe; 15. Rotary joint; 16. Moving frame; 17. Mounting pipe; 18. Support column; 19. Second jacket; 20. First jacket; 21. Plastic pipe; 22. Base; 23. Bucket lid; 24. Heating arc block; 25. Short shaft; 26. Second arc plate; 27. First arc plate; 28. First mating opening; 29. ​​Second mating opening; 30. Locking block; 31. Locking hole; 32. First piston cylinder; 33. Conveying unit; 34. Support ring; 35. First spring; 36. First moving piston; 37. First pull rod; 38. First short pipe; 39. Second short pipe; 40. Second piston cylinder; 41. Second spring; 42. Second moving piston; 43. Second pull rod; 44. Opening; 45. Second clamping plate. Detailed Implementation

[0041] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0042] Reference Figures 1-9 A plastic bucket tube drawing and welding integrated manufacturing process includes a tube drawing device 1, a cutting device 2, and a welding device 3; the cutting device 2 is set at the discharge end of the tube drawing device 1 and is used to cut the continuous plastic tube 21 extruded by the tube drawing device 1 to a fixed length.

[0043] The specific manufacturing process includes the following steps:

[0044] S1. Preparation of pipe drawing blank: Continuous plastic pipes are extruded through pipe drawing equipment to provide qualified blanks for the molding of plastic bucket bodies;

[0045] S2, Fixed-length cutting process: The continuous plastic tube 21 extruded by the tube drawing equipment 1 is conveyed to the cutting equipment 2, and the continuous plastic tube 21 is precisely cut to a fixed length to obtain a barrel blank with uniform specifications.

[0046] S3. Workpiece positioning and clamping: The cut barrel blank, the preset base 22 and the barrel cover 23 are transferred to the welding equipment 3, and the three are coaxially positioned and clamped by the clamping structure of the welding equipment 3.

[0047] S4. Inner support arrangement: Insert the annular support structure in the contracted state in the welding equipment 3 into the internal channel of the barrel blank from one end. Then control the radial expansion of the support structure to form an annular support surface that matches the inner side of the barrel, and support the inner mating parts of the barrel blank, base 22 and barrel cover 23.

[0048] S5. Heating and welding: The welding equipment 3 is used to weld the mating surfaces of the coaxially positioned and internally supported barrel blank, base 22 and barrel lid 23 to complete the overall welding and forming of the plastic barrel.

[0049] Further explanation: Among them, the pipe extrusion equipment 1 is a high-precision extruder, which is equipped with a precision temperature control system and an extrusion speed closed-loop control system. It can heat and melt thermoplastic raw materials such as HDPE and PP, and then extrude them to form a continuous tubular preform (i.e., continuous plastic pipe 21) with uniform wall thickness (accuracy up to ±0.1mm). This equipment needs to meet the stable control of the plastic molten state to ensure the consistency of the pipe preform diameter and wall thickness. It is suitable for the molding needs of large-capacity regular cylindrical plastic buckets such as 200L round drums. Its extrusion speed can reach several meters per minute, realizing continuous production.

[0050] Equipped with a fully automatic vacuum sizing chamber and gradient cooling system. The vacuum sizing chamber is made of 304 stainless steel and features a precisely positioned sizing sleeve inside. A fully automatic negative pressure closed-loop control system ensures stable sizing pressure control. Operators can set the required negative pressure value via an HMI (Human-Machine Interface). The system uses a negative pressure sensor to collect the pressure signal inside the chamber in real time and transmits it to the frequency converter, automatically adjusting the vacuum pump speed to quickly achieve constant negative pressure (control accuracy up to ±0.001MPa). This ensures the tube blank adheres tightly to the inner wall of the sizing sleeve under negative pressure, guaranteeing the accuracy of the tube blank's outer diameter. The cooling system employs a segmented gradient cooling design. The first stage uses medium-temperature water cooling at 25-30℃, while the second stage uses low-temperature water cooling at 15-20℃ to prevent internal stress or surface cracking of the tube blank due to excessively rapid cooling. The cooling water path is arranged in a circular pattern with a spray hole density ≥10 holes / cm², ensuring sufficient and uniform cooling water flow and achieving tube blank stability.

[0051] The system employs a multi-track "one-to-many" synchronous traction mechanism, matched with a specially structured synchronous servo motor. A single driver can simultaneously drive multiple permanent magnet synchronous motors, achieving stable low-frequency torque output. The traction track surface is made of highly elastic, wear-resistant rubber and equipped with an adaptive pressure adjustment device that automatically adjusts the clamping pressure according to the tube blank wall thickness, preventing deformation or surface scratches during traction. The traction mechanism's speed range is 0.5-5 m / min, perfectly matching the extrusion speed requirements, ensuring that the continuous plastic tube 21 does not stretch or accumulate during traction, further guaranteeing the dimensional stability of the tube blank. This section allows the shaped plastic tube 21 to be transported to the cutting equipment 2.

[0052] Cutting equipment 2 is a CNC cutting machine with synchronous control function that matches the extrusion speed of tube drawing equipment 1. It can cut continuous plastic tube 21 to a fixed length according to the preset height parameters of 200L cylindrical barrel, and the cutting length accuracy is controlled within ±0.5mm. This equipment needs to be equipped with a precise positioning mechanism and cutting execution components to ensure that the cut end face is flat and burr-free, so as to avoid affecting the subsequent hot melt welding sealing and structural strength of the barrel bottom and barrel lid. The scraps generated during the cutting process can be directly recycled to meet the material recycling requirements.

[0053] Specifically, a ball screw slide structure driven by a servo motor, coupled with a grating ruler positioning feedback device, achieves a positioning accuracy of ±0.05mm. The slide drives the cutting execution component to reciprocate along the tube blank conveying direction. The grating ruler collects the position information of the cutting component in real time and feeds it back to the control system, achieving precise control of the cutting start position. Simultaneously, a tube blank centering fixture is provided. This fixture adopts a three-jaw pneumatic centering structure, which can automatically adjust the clamping range according to the outer diameter of the continuous plastic tube 21 (suitable for φ500-φ600mm). During clamping, an elastic contact design is used to avoid damage to the tube blank surface, while ensuring that the axis does not deviate during tube blank cutting, guaranteeing that the cutting end face is perpendicular to the tube blank axis.

[0054] Employing a fully automatic chip-free cutting mechanism, this system is equipped with a carbide circular saw blade (diameter ≥300mm, number of teeth ≥80). The saw blade speed is infinitely adjustable within the range of 2000-5000 r / min, and the maximum cutting thickness can reach 130mm, fully meeting the cutting requirements for 200L cylindrical barrels with wall thicknesses (typically 3-8mm). The cutting mechanism features a fully enclosed dust cover design with an internal high-pressure air blowing device to promptly remove plastic debris from the saw blade surface during cutting, preventing debris adhesion and burrs on the cut end face. It also features a saw blade cooling system using specialized cutting fluid for spray cooling, which reduces saw blade temperature, extends saw blade life, and minimizes melting and deformation of the tube blank end face due to high temperatures during cutting.

[0055] The welding equipment 3 includes a clamping structure for coaxially positioning and clamping the cut plastic tube 21, base 22, and bucket lid 23 respectively, and a heating structure for welding the mating surfaces of the three; wherein, the base 22 and bucket lid 23 are injection molded by an injection molding machine.

[0056] The welding equipment 3 also includes a processing table 4. A fixture structure is mounted on the processing table 4. The fixture structure includes a first clamping part, a second clamping part, and a third clamping part mounted on the processing table 4. The second clamping part and the third clamping part are arranged opposite to each other and can move along their respective length directions. Specifically:

[0057] The first clamping part includes a bracket 9 and a support base 12 mounted on the processing table 4. Two driving components 10 are mounted on the bracket 9. The driving components 10 can be electric push rods, cylinders, or hydraulic cylinders. The output end of the driving component 10 is fixed with a first clamping plate 11 and abuts against the plastic tube 21. The operation of the driving component 10 can drive the first clamping plate 11 to move up or down. The bottom of the first clamping plate 11 is arc-shaped and fits with the outer wall of the plastic tube 21. A second clamping plate 45 is fixed on the support base 12. The second clamping plate 45 is used to support the bottom of the plastic tube 21. The upper end of the second clamping plate 45 is provided with an arc-shaped surface and fits with the outer surface of the plastic tube 21. Through the cooperation of the first clamping plate 11 and the second clamping plate 45, the plastic tube 21 can be clamped with a clamping pressure of 0.3-0.8MPa and a coaxiality error of ≤0.2mm.

[0058] The second clamping part includes a first movable plate 7, on which an installation tube 17 is fixed. A first clamp 20 is fixed on the installation tube 17. The barrel lid 23 is limited and installed in the first clamp 20. The first clamp 20 can be provided with a buckle or negative pressure adsorption to lock the barrel lid 23, ensuring that it is stably located in the first clamp 20. The first clamp 20 is configured to cooperate with the barrel lid 23, and has an opening 44 at its end to allow heat to be discharged. Air can also be introduced through this opening during welding to cool the welded part.

[0059] Among them, such as Figure 5 As shown, the bucket lid 23 is not a simple lid, but a bucket mouth structure at the end of the plastic bucket, with external threads on its outer wall for screwing in with a threaded cap.

[0060] The third clamping part includes a second movable plate 8, on which a support column 18 is installed. A second clamping sleeve 19 is fixed on the support column 18. The second clamping sleeve 19 is coaxially arranged with the first clamping sleeve 20. The base 22 is limited within the second clamping sleeve 19. Similarly, the second clamping sleeve 19 is configured to cooperate with the base 22 and is fixed by means of a latch or negative pressure adsorption.

[0061] The processing table 4 is equipped with two sets of first electric slide rails (or other drive structures, such as cylinder drive). Each of the two sets of first electric slide rails is equipped with a first slider. The upper ends of the two first sliders are respectively fixed with a movable seat 6. The first movable plate 7 and the second movable plate 8 are fixed to the movable seat 6 by bolts, so that the first movable plate 7 and the second movable plate 8 can be controlled to move independently.

[0062] The heating structure includes a movable frame 16 working on a processing table 4. A second electric slide rail (or other drive structure, such as cylinder drive) is installed on the processing table 4. A second electric slider is slidably connected to the second electric slide rail. The movable frame 16 is fixed on the second electric slider. The movement of the second electric slider can move the movable frame 16. Two heating rings 5 ​​are installed on the movable frame 16. The movable frame 16 includes a U-shaped plate and two guide rods are fixed inside. A sliding support frame (not shown in the figure) is sleeved on the guide rod. The heating rings 5 ​​are installed on the support frame. A fourth spring is fixed between the support frame and the U-shaped plate. The fourth spring is used for the reset of the support and the heating rings 5 ​​so that the heating rings 5 ​​can move towards the plastic tube 21 for heating and melting. The heating ring (5) has a power of 1-3kW, a heating temperature of 200-240℃ for HDPE and 180-220℃ for PP, a heating duration of 15-60 seconds, and a distance of 2-5mm between the heating arc block (24) and the workpiece mating surface.

[0063] The heating ring 5 has a notch, and a heating arc block 24 is movably connected in the notch. The heating arc block 24 is hinged to the heating ring 5 by a short shaft 25, and a torsion spring is provided at the movable part so that the heating arc block 24 can be reset.

[0064] The heating ring 5 and the heating arc block 24 form a complete ring shape, and there are heating wires or heating tubes inside, which are used to heat the heating ring 5 and the heating arc block 24, thereby heating the plastic tube 21 and the like.

[0065] During the welding process, the plastic tube 21, base 22, and lid 23 need to be clamped. However, these parts are all made of plastic and require a certain pressure to be applied during heating. Without support, they will deform during heating and compression, resulting in poor welding quality and uneven weld surfaces. Therefore, the welding equipment 3 also includes a support structure, which is a radially expandable annular structure that is initially in a contracted state. During the welding process, the contracted support structure is inserted into the plastic tube 21, and the support structure expands radially into an annular shape, providing uniform support to the inner sides of the plastic tube 21, base 22, and lid 23. After the welding is completed, the support structure contracts radially and is removed from one side of the lid 23.

[0066] Further explanation of the support mechanism: The support structure also includes a conveying section 33 that passes through the mounting pipe 17. The conveying section 33 is fixedly installed inside the mounting pipe 17, meaning it can slide. A stop is rotatably provided at the end of the conveying section 33, and the stop abuts against the base 22. The conveying section 33 includes a through pipe (such as...) that passes through the mounting pipe 17. Figure 9 The left-side pipe, the middle sleeve, and the right-side sleeve are equipped with connecting blocks fixed to the inner wall of the pipe. A third spring is fixed to the connecting blocks and the sleeve, which enables the conveying part 33 to have a telescopic function; wherein, the stop block is installed on the sleeve.

[0067] Four support rings 34 are installed on the conveying section 33. The positions of the support rings 34 are opposite to the ends of the plastic tube 21, the base 22, and the lid 23. The support rings 34 are provided with two first short tubes 38 and two second short tubes 39 that communicate with the conveying section 33. The two first short tubes 38 and the two second short tubes 39 are staggered and arranged in a cross shape.

[0068] A first piston cylinder 32 is fixed on the first short tube 38. A first movable piston 36 slides inside the first piston cylinder 32. A first spring 35 is fixed on the first movable piston 36 and the first piston cylinder 32. A first pull rod 37 is fixed on the first movable piston 36. A first arc plate 27 is fixed on the first pull rod 37.

[0069] A second piston cylinder 40 is fixed on the second short tube 39. A second movable piston 42 is slidably connected inside the second piston cylinder 40. A second spring 41 is fixed on the second movable piston 42 and the second piston cylinder 40. A second pull rod 43 is fixed on the second movable piston 42. A second arc plate 26 is fixed on the second pull rod 43.

[0070] The elastic force of the first spring 35 is less than that of the second spring 41; after the support structure expands, the gap between it and the inner side of the barrel is 0.1-0.3mm, and the support pressure is 0.2-0.5MPa.

[0071] Among them, the first piston cylinder 32 and the second piston cylinder 40 are equipped with limiting blocks. When the first arc plate 27 and the second arc plate 26 abut against the inner wall of the plastic tube 21, the first moving piston 36 and the second moving piston 42 abut against the limiting blocks, thus limiting them and preventing the first arc plate 27 and the second arc plate 26 from over-supporting the plastic tube 21 and causing it to deform.

[0072] Furthermore, a power unit 13 is installed on the processing table 4, and the output end of the power unit 13 is connected to a fluid pipe 14. The fluid pipe 14 is connected to the mounting pipe 17 through a rotary joint 15. The power unit 13 can supply air or hydraulic oil to the conveying unit 33. Since the elastic force of the first spring 35 is less than that of the second spring 41, the first moving piston 36 and the second moving piston 42 will move in a sequential order.

[0073] When the two first arc-shaped plates 27 and the two second arc-shaped plates 26 abut against each other, they form a ring. To ensure the stability of the ring, the abutting parts are locked by a locking part. The locking part includes two first mating openings 28 located on the inner sides of both ends of the first arc-shaped plates 27 and two second mating openings 29 located on the outer sides of both ends of the second arc-shaped plates 26. A locking block 30 is fixed on the first arc-shaped plates 27 and located at the first mating openings 28. A lock hole 31 is provided on the second arc-shaped plates 26 and located at the second mating openings 29. When the first arc-shaped plates 27 and the two second arc-shaped plates 26 abut against each other, the first mating openings 28 and the second mating openings 29 fit together, and the locking block 30 is engaged in the lock hole 31.

[0074] This invention is used for the production and processing of 200L cylindrical drums. Depending on the size and volume of the large-capacity cylindrical drum, the corresponding structure can be changed, eliminating the need for separate molds like traditional molds, making this application simpler. The specific production and processing process for the 200L cylindrical drum is as follows:

[0075] First, the pipe drawing device 1 extrudes the plastic pipe 21 and cools it before conveying it to the cutting device 2. The cutting device 2 can cut the plastic pipe 21 into equal-length parts. The equal-length plastic pipe 21 is then conveyed to the welding device 3, which welds the plastic pipe 21, the base 22 and the bucket lid 23 into a 200L round bucket.

[0076] The staff installs the base 22 inside the second clamp 19, and then installs the bucket lid 23 through the support structure inside the first clamp 20. Next, the plastic tube 21 is placed on the second clamping plate 45 manually or by a robotic arm. The placement position of the plastic tube 21 is adjusted by monitoring with a laser calibration device so that its axis is aligned with the central reference line of the second clamping plate 45. The first slider is driven to move by the first electric slide rail, thereby moving the moving seat 6 and the first moving plate 7, which in turn moves the installation tube 17 and the conveying part 33 until the stop block abuts against the bucket lid 23. At this time, the plastic tube 21, the base 22, and the bucket lid 23 do not abut against each other, that is, there is space between the plastic tube 21 and the base 22 and the bucket lid 23 to accommodate the heating ring 5.

[0077] At this time, the support structure is opposite to the plastic tube 21, the base 22, and the port of the lid 23, but not flush with the port. When the power unit 13 is activated, the fluid can be transported to the conveying unit 33 through the fluid tube 14 and the rotary joint 15 in sequence. The fluid in the conveying unit 33 flows to the first short tube 38 and the second short tube 39 into the first piston cylinder 32 and the second piston cylinder 40. Since the elastic force of the first spring 35 is less than that of the second spring 41, the first moving piston 36 and the second moving piston 42 will move in a sequential order.

[0078] Specifically, when the fluid enters the first piston cylinder 32, the pressure inside the first piston cylinder 32 increases, thereby driving the first moving piston 36 to move, which in turn drives the first pull rod 37 and the first arc plate 27 to move. At this time, the first spring 35 is stretched, and the resistance to driving the first moving piston 36 increases accordingly.

[0079] The increased pressure inside the second piston cylinder 40 can drive the second moving piston 42 to move, thereby driving the second tie rod 43 and the second arc plate 26 to move.

[0080] As the power unit 13 continuously delivers fluid, the two first arc-shaped plates 27 abut against the inner wall of the plastic tube 21, followed by the second arc-shaped plate 26 abutting against the plastic tube 21, and the first fitting port 28 and the second fitting port 29 fitting together. The locking block 30 is inserted into the locking hole 31, so that the two first arc-shaped plates 27 and the two second arc-shaped plates 26 form a complete ring. Similarly, the ring formed by the first arc-shaped plates 27 and the two second arc-shaped plates 26 also supports the base 22 and the lid 23 from the inside.

[0081] It is important to note that at this time, the ring inside the plastic tube 21 must be aligned vertically with the second clamping plate 45 to ensure even force distribution during subsequent clamping. Next, the drive unit 10 is activated, which drives the first clamping plate 11 to move downward. The first clamping plate 11 moves downward and abuts against the plastic tube 21, which, together with the second clamping plate 45, can clamp the plastic tube 21. Because the plastic tube 21 is supported by the ring inside, it will not deform, ensuring the quality of subsequent welding.

[0082] Next, the moving frame 16 is driven to move the heating ring 5 into the space between the plastic tube 21, the base 22, and the lid 23. During the movement of the heating ring 5, the heating arc block 24 is moved. When the heating arc block 24 comes into contact with the conveying part 33, the heating arc block 24 rotates around the short axis 25 due to the obstruction of the conveying part 33, so that the conveying part 33 enters the heating ring 5. When the heating arc block 24 is no longer limited, it is reset under the action of the torsion spring. At this time, the heating ring 5 and the heating arc block 24 have been preheated.

[0083] Next, the first electric slide rail drives the first slider to move, causing the two moving seats 6 to move relative to each other, thereby compressing the conveying part 33, which in turn causes the base 22 and the lid 23 to move relative to each other. Finally, the base 22 and the lid 23 abut against the heating ring 5 and the heating arc block 24 and are pressed towards the plastic tube 21. The heating ring 5 and the heating arc block 24 can heat and melt the welding end faces of the base 22, the lid 23, and the plastic tube 21. Then, the first slider drives the moving seats 6 and the base 22 and the lid 23 to quickly reset, and the heating ring 5 and the heating arc block 24 quickly disengage. The first slider drives the moving seats 6 and the base 22 and the lid 23 to move again, so that the base 22 and the lid 23 abut against the plastic tube 21. In this way, the heat-melted end faces are connected together, and a certain pressure is applied and maintained for a period of time until solidification, thus completing the welding work of the plastic bucket.

[0084] Due to the support of the ring, the plastic tube 21, base 22, and lid 23 will not deform when heated and pressure welded, thus ensuring the quality of the weld.

[0085] Then, the power unit 13 extracts the fluid. Under the action of the first spring 35 and the second spring 41, the second arc plate 26 is reset first, followed by the first arc plate 27, thus reducing the volume of the ring. The first slider drives the moving seat 6, the first moving plate 7, the conveying unit 33, and the support structure to move, so that the support structure is removed from the bucket lid 23. Under the action of the third spring, the conveying unit 33 is reset. The driving unit 10 drives the first clamping plate 11 to move upward and reset. Then, the plastic bucket is removed, and the excess part can be cut off.

[0086] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A plastic drum draw tube welding and forming integrated manufacturing process, characterized in that, It comprises the following steps: S1, pipe blank preparation: extruding a continuous plastic pipe (21) through a pipe drawing device (1) to provide qualified blanks for plastic bucket body molding; S2, fixed-length cutting process: the continuous plastic pipe (21) extruded by the pipe drawing device (1) is transported to a cutting device (2) to accurately cut the continuous plastic pipe (21) to a fixed length to obtain a bucket body blank with uniform specifications; S3, workpiece positioning and clamping: the cut bucket body blank, a pre-set base (22) and a bucket cover (23) are transferred to a welding device (3), and the three are coaxially positioned and clamped by the clamp structure of the welding device (3); S4, inner side support arrangement: the ring-shaped support structure in the contracted state in the welding device (3) is inserted into the internal passage of the bucket body blank from one end, and then the support structure is controlled to expand radially to form a ring-shaped support surface adapted to the inner side of the bucket body, thereby supporting the inner side joint parts of the bucket body blank, the base (22) and the bucket cover (23); S5, heating and welding forming: the abutting surfaces of the coaxially positioned and internally supported bucket body blank, the base (22) and the bucket cover (23) are welded by the heating structure of the welding device (3) to complete the overall welding and forming of the plastic bucket.

2. The integrated manufacturing process of a plastic bucket with a draw tube welded and formed according to claim 1, wherein, The pipe drawing device (1) is a high-precision extruder equipped with a full-automatic vacuum sizing box and a multi-track synchronous traction mechanism; the plastic raw material is selected from HDPE or PP thermoplastic, which is dried in a 80-120℃ drying oven for 2-4 hours before use, with a water content of ≤0.1%; the heating temperature of the pipe drawing device (1) is 180-230℃ for HDPE and 160-220℃ for PP, and the extrusion speed is 0.5-5m / min.

3. The integrated manufacturing process of a plastic drum with a draw tube welded and formed according to claim 1, wherein, The welding device (3) further comprises a machining table (4), and the clamp structure is arranged on the machining table (4). The clamp structure comprises a first clamping part, a second clamping part and a third clamping part arranged on the machining table (4), and the second clamping part and the third clamping part are oppositely arranged.

4. The manufacturing process of claim 3, wherein, The first clamping part comprises a support (9) and a support seat (12) arranged on the machining table (4). Two driving members (10) are installed on the support (9). The output end of the driving member (10) is fixed with a first clamping plate (11) and abuts against the outer wall of the plastic pipe (21). The support seat (12) is fixed with a second clamping plate (45). The second clamping plate (45) is used to support the bottom of the plastic pipe (21). The clamping pressure is 0.3-0.8MPa, and the coaxiality error is ≤0.2mm.

5. The integrated manufacturing process of a plastic drum with a draw tube welded and formed according to claim 3, wherein, The second clamping part comprises a first moving plate (7). The first moving plate (7) is fixed with a mounting pipe (17). The mounting pipe (17) is fixed with a first clamping sleeve (20). The bucket cover (23) is limitedly installed in the first clamping sleeve (20).

6. The integrated manufacturing process of a plastic drum with a draw tube welded and formed according to claim 3, wherein, The third clamping part comprises a second moving plate (8). The second moving plate (8) is installed with a support column (18). The support column (18) is fixed with a second clamping sleeve (19). The second clamping sleeve (19) is coaxially arranged with the first clamping sleeve (20). The base (22) is limitedly arranged in the second clamping sleeve (19).

7. The integrated manufacturing process of a plastic drum with a draw tube welded and formed according to claim 3, wherein, The heating structure comprises a movable frame (16) arranged on the processing table (4) and movable, two heating rings (5) are installed on the movable frame (16), a notch is formed in the heating ring (5), and a heating arc-shaped block (24) is movably connected in the notch; the heating ring (5) has a power of 1-3 kW, a heating temperature of HDPE 200-240 DEG C, a heating temperature of PP 180-220 DEG C, a heating duration of 15-60 seconds, and a distance of 2-5 mm between the heating arc-shaped block (24) and a workpiece abutting surface.

8. The integrated manufacturing process of a plastic drum with a draw tube welded and formed according to claim 5, wherein, The supporting structure further comprises a conveying part (33) arranged through the mounting pipe (17), four supporting rings (34) are installed on the conveying part (33), and two first short pipes (38) and two second short pipes (39) in communication with the conveying part (33) are arranged on the supporting ring (34). The first short pipe (38) is fixedly provided with a first piston cylinder (32), a first movable piston (36) is slidably arranged in the first piston cylinder (32), the first movable piston (36) and the first piston cylinder (32) are fixedly provided with a first spring (35), the first movable piston (36) is fixedly provided with a first pull rod (37), and the first pull rod (37) is fixedly provided with a first arc-shaped plate (27). The second short pipe (39) is fixedly provided with a second piston cylinder (40), a second movable piston (42) is slidably connected in the second piston cylinder (40), the second movable piston (42) and the second piston cylinder (40) are fixedly provided with a second spring (41), the second movable piston (42) is fixedly provided with a second pull rod (43), and the second pull rod (43) is fixedly provided with a second arc-shaped plate (26). The elastic force of the first spring (35) is smaller than that of the second spring (41), the gap between the supporting structure and the inner side of the barrel body is 0.1-0.3 mm after expansion, and the supporting pressure is 0.2-0.5 MPa.

9. The integrated manufacturing process of claim 8, wherein, When the two first arc-shaped plates (27) and the two second arc-shaped plates (26) abut against each other, the two first arc-shaped plates (27) and the two second arc-shaped plates (26) form a ring, and the abutment is locked by the locking part.

10. The integrated manufacturing process of a plastic drum with a draw tube welded and formed according to claim 9, wherein, The locking part comprises two first engagement openings (28) arranged on the inner sides of the two ends of the first arc-shaped plate (27), two second engagement openings (29) are arranged on the outer sides of the two ends of the second arc-shaped plate (26), a locking block (30) is fixedly arranged on the first arc-shaped plate (27) and located at the first engagement opening (28), a locking hole (31) is arranged on the second arc-shaped plate (26) and located at the second engagement opening (29), and when the first arc-shaped plate (27) and the two second arc-shaped plates (26) abut against each other, the first engagement opening (28) and the second engagement opening (29) are engaged, and the locking block (30) is buckled into the locking hole (31).

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