Plastic pipe connector external thread forming device

Abstract

The invention relates to a plastic pipe connector external thread forming device, and belongs to the technical field of plastic pipe connector thread forming equipment. The device comprises a rack, a storage mechanism and a conveying mechanism are arranged on the rack, the device is further provided with a thermal forming mechanism and a positioning mechanism, the thermal forming mechanism comprises a supporting sleeve, a heating rod and a forming mold, and the supporting sleeve is used for being inserted into a plastic pipe to support the plastic pipe; the heating rod is coaxial with the supporting sleeve and is used for being inserted into the supporting sleeve to heat the plastic pipe; the forming die comprises two forming modules symmetrically arranged on the left side and the right side of the supporting sleeve, and half-section threaded protrusions are arranged on the inner side walls of the two forming modules. The positioning mechanism is used for clamping the plastic pipe conveyed to the thermal forming mechanism and moving the plastic pipe so that the plastic pipe and the supporting sleeve can be kept coaxial. The plastic pipe can be prevented from being greatly deformed after being heated and softened, and the thread forming quality is better.

Description

Technical Field

[0001] The present invention relates to the technical field of plastic pipe interface thread forming equipment, and in particular to an external thread forming device for plastic pipe interfaces. Background Art

[0002] Due to its excellent corrosion resistance, light weight, easy installation and maintenance, etc., plastic pipes are widely used in modern construction, industry, agriculture, and municipal engineering fields. During the application process of plastic pipes, it is usually necessary to process external threads at the interfaces to facilitate the connection and sealing of plastic pipes.

[0003] There are various ways to process threads at the interfaces of plastic pipes. Among them, processing the external threads at the interfaces of plastic pipes by thermoforming is a relatively special processing method. Compared with other processing methods such as injection molding and mechanical cutting, processing the external threads at the interfaces of plastic pipes by thermoforming can reduce material waste, improve production efficiency, and make the produced products have better surface quality.

[0004] The steps of processing the external threads at the interfaces of plastic pipes by thermoforming usually include first heating the interface end of the plastic pipe to soften the plastic, and then applying pressure to the plastic pipe through a mold to form its end into a shape with external threads. In the prior art, a special forming device is generally used to perform thermoforming processing on the interface end of the plastic pipe. For example, a patent with the authorization announcement number CN110076985B discloses an external thread hot extrusion forming machine for a fire extinguisher siphon pipe. The forming machine includes a thread forming assembly installed on a frame and used for extruding the interface of the plastic pipe, a preheating assembly used for heating the interface of the plastic pipe, and a conveying assembly used for combing the plastic pipes and sequentially feeding them into the preheating assembly for heating and the thread forming assembly for thread forming in groups.

[0005] This forming machine can process threads at the end of the plastic pipe with high production efficiency. However, the preheating assembly and the thread forming assembly in this forming machine are independent of each other and have a certain interval. The plastic pipe is first preheated at the preheating assembly and then conveyed to the thread forming assembly for thread forming. Since the plastic pipe will become soft after the preheating treatment, the softened plastic pipe is prone to deformation under the action of gravity during the movement to the thread forming assembly. When the deformed plastic pipe is subjected to thread forming at the thread forming assembly, it is easy to have uneven thread depth and uneven pitch during the thread forming, which affects the thread forming quality and has an impact on the subsequent assembly of the plastic pipe. Summary of the Invention

[0006] The present invention provides a device for forming external threads at the interface of a plastic pipe, aiming to solve the technical problem in the prior art that when an external thread hot extrusion forming machine for plastic pipes processes external threads, since the preheating component and the forming component are independent of each other and have a gap, the plastic pipe cannot be extruded and formed in time after being heated and softened, and is prone to deformation under the action of gravity, affecting the quality of thread forming.

[0007] To solve the above problems, the device for forming external threads at the interface of a plastic pipe provided by the present invention adopts the following technical solutions: A device for forming external threads at the interface of a plastic pipe includes a frame. A storage mechanism for storing plastic pipes and a conveying mechanism for conveying the plastic pipes to move from left to right are provided on the frame. A hot forming mechanism and a positioning mechanism are also provided on the frame. The hot forming mechanism includes: A support sleeve, whose axis extends in the front-rear direction, can move back and forth on the frame, and is used to insert into the plastic pipe to support the plastic pipe; A heating rod, coaxial with the support sleeve, can move back and forth on the frame, and is used to insert into the support sleeve to heat the plastic pipe; A forming die, including two forming modules with semi-circular arc cross-sections symmetrically arranged on the left and right sides of the support sleeve. Semi-segmented thread protrusions are provided on the inner side walls of the two forming modules. The two forming modules can move synchronously closer to or away from each other in the left-right direction. When the two forming modules are abutted against each other, they can cooperate with the support sleeve to enclose a thread cavity for extruding and forming the interface end of the plastic pipe; The positioning mechanism is used to clamp the plastic pipe conveyed to the hot forming mechanism and move the plastic pipe to keep the plastic pipe coaxial with the support sleeve.

[0008] Adopting the above technical solutions, when the plastic pipe moves to the hot forming mechanism, the positioning mechanism clamps the plastic pipe and moves the plastic pipe to keep it coaxial with the support sleeve. The support sleeve inserts into the plastic pipe in the front-rear direction to support the plastic pipe, and the heating rod inserts into the support sleeve to heat the plastic pipe. Since the support sleeve supports the plastic pipe, it can prevent the plastic pipe from sagging and deforming significantly under the action of gravity after being heated and softened. The support sleeve can also prevent the heat of the heating rod from being directly transferred to the plastic pipe, avoiding too high heating temperature.

[0009] After the plastic pipe is heated, the two forming modules move closer to each other to extrude the end of the softened plastic pipe, pressing external threads on the outer side wall of the plastic pipe. During this process, the softened plastic pipe is always supported by the support sleeve, and the position of the plastic pipe remains unchanged. Compared with the prior art, the plastic pipe does not need to be moved from the heating station to the extrusion forming station. After the plastic pipe is heated, it can be extruded and formed at the same station. In this way, the connection between the heating process and the extrusion forming process is more coherent. Immediately after the plastic pipe is softened, it can be extruded and formed, which can not only improve production efficiency but also avoid the problem that the softened plastic pipe is deformed significantly under the action of gravity due to long-term lack of support. The deformation of the plastic pipe after heating and softening is smaller, the depth of the processed threads can be more consistent, the pitch is more uniform, and the quality of the formed threads is better. At the same time, the heating mechanism and the extrusion forming mechanism are concentrated in one place, which also makes the equipment structure more concise.

[0010] Further, the thermoforming mechanism further includes a movable frame and a movable frame driving mechanism. The support sleeve is fixedly connected to the movable frame. The two forming modules are installed on the movable frame with left-right guiding and sliding. The movable frame can be driven by the movable frame driving mechanism to move forward and backward towards the plastic pipe clamped by the positioning mechanism, so that the support sleeve is inserted into the plastic pipe.

[0011] Further, an extrusion driving mechanism is provided on the movable frame. The extrusion driving mechanism includes an extrusion cylinder, a pressing block, a moving block and two connecting rods. The extrusion cylinder has a driving output end that can move back and forth. The pressing block is connected to the driving output end of the extrusion cylinder. The pressing block is located between the extrusion cylinder and the forming die. There are two moving blocks. The two moving blocks are respectively connected to the two forming modules. The two moving blocks are both installed on the movable frame with left-right guiding and sliding. The two connecting rods are symmetrically arranged on the left and right sides of the support sleeve. One end of the connecting rod is hinged to the pressing block around a vertically extending rotation axis, and the other end is hinged to the corresponding moving block around a vertically extending rotation axis. The spacing dimension of the hinge points of the two connecting rods on the pressing block is smaller than the spacing dimension of the hinge points of the two connecting rods on the two moving blocks.

[0012] Adopting the above technical solution, when the extrusion cylinder drives the pressing block to move towards the forming die, it can drive the two moving blocks to move away from each other through the two connecting rods, thereby driving the two forming modules to move away from each other. When the extrusion cylinder drives the pressing block to move away from the forming die, it can drive the two moving blocks to move closer to each other synchronously through the two connecting rods, that is, drive the two forming modules to move closer to each other synchronously. The synchronous mutual approach and synchronous mutual separation of the two forming modules are realized through the one-way drive of one extrusion cylinder. The drive structure is relatively simple, and there is no need to set two drive structures to drive the two forming modules respectively, which can save power costs.

[0013] Furthermore, the heating rod is connected to the pressing block, and when the extrusion cylinder drives the pressing block to move toward the forming mold, the heating rod can be driven to insert into the supporting sleeve.

[0014] By adopting the above technical scheme, when the extrusion cylinder drives the pressing block to move toward the forming mold, it can not only drive the two forming modules to move away from each other synchronously, so that the supporting sleeve is exposed to facilitate the insertion of the supporting sleeve into the plastic tube, but also enable the heating rod to be inserted into the supporting sleeve to heat the plastic tube. When the extrusion cylinder drives the pressing block to move away from the forming mold, it can not only drive the two forming modules to move closer to each other synchronously to extrude the softened plastic tube, but also drive the heating rod to leave the supporting sleeve to facilitate the cooling of the formed plastic tube. The movement of the pressing block toward the forming mold or away from the forming mold can drive the forming mold and the heating rod to move synchronously. There is no need to drive the movement of the heating rod and the forming module separately. The structure is simpler and more ingenious, which can save power costs.

[0015] Furthermore, an extrusion ring that can move forward and backward is provided on the movable frame, and the extrusion ring is mounted on the supporting sleeve. The extrusion ring is located on the side of the forming mold close to the movable frame and is opposite to the threaded cavity front and back. The pull rod is a telescopic rod. The pull rod can be driven by the extrusion cylinder and lengthened after the two forming modules are abutted, so that the pressure block can be driven by the extrusion cylinder after the two forming modules are abutted and continue to move back to the forming mold. The pressure block is connected with the extrusion ring in a transmission connection, and the extrusion ring can be driven by the pressure block moving back to the forming mold to move toward the threaded cavity.

[0016] By adopting the above technical solution, by setting the pull rod as a telescopic rod, after the two molding modules abut against each other, the extrusion cylinder can still drive the pressure plate to continue to move back to the molding mold, and by providing an extrusion ring and making the extrusion ring transmission connected with the pressing block, the pressing block can drive the extrusion ring to move toward the threaded cavity while continuing to move back to the molding mold, so that the extrusion ring is pressed tightly against the end of the plastic tube. In the process of extrusion molding of the plastic tube, the melted part of the plastic tube is pressed toward the threaded cavity, so that the threaded part of the plastic tube is denser after molding and the structural strength is higher.

[0017] Furthermore, the movable frame is a box structure, the support sleeve is connected to the outer wall of the movable frame and communicates with the inner cavity of the movable frame, an air inlet is provided on the side wall of the movable frame, a cooling fan is installed at the air inlet, and the cooling fan can blow air toward the inner cavity of the movable frame through the air inlet.

[0018] By adopting the above technical solution, the movable frame is a box structure, and the inner cavity of the support sleeve is connected to the inner cavity of the movable frame. The wind blown into the inner cavity of the movable frame by the cooling fan can be blown into the plastic pipe through the support sleeve, thereby accelerating the cooling speed of the formed plastic pipe.

[0019] Further, the conveying mechanism includes two sets of conveying chain assemblies arranged symmetrically front and back. Each conveying chain assembly includes a chain and support blocks connected to the chain. The support blocks are provided with grooves for placing plastic pipes with the openings facing away from the chain.

[0020] With the above technical solution, the plastic pipes can be placed in the grooves on two symmetrically arranged support blocks front and back and conveyed to the right, and the conveying process is more stable.

[0021] Further, the storage mechanism includes a storage box. A storage cavity is provided inside the storage box. The bottom of the storage cavity communicates with a discharging cavity extending vertically for storing multiple plastic pipes stacked one above the other. The width dimension of the discharging cavity is adapted to the outer diameter dimension of the plastic pipes to be processed. A support plate is provided at the bottom of the discharging cavity for supporting under the plastic pipe at the bottommost in the discharging cavity. The left end of the support plate is elastically hinged to the frame around a rotation axis extending front and back. The right end of the support plate is higher than the left end. The left side wall of the groove in the support block on the upper half of the chain is higher than the right side wall. When the support block moves to the right, the left side wall of the groove can push the plastic pipe at the bottommost to the right and push the support plate to swing downward, so as to pick out the plastic pipe from the bottom of the discharging cavity and drop it into the groove.

[0022] With the above technical solution, each time the support block moves to the bottom of the discharging cavity, it can pick out a plastic pipe and drive the plastic pipe to move to the right, and the remaining plastic pipes fall downward under the action of gravity to achieve feeding, realizing the automatic feeding of plastic pipes and improving the production efficiency.

[0023] Further, the width dimension of the discharging cavity can be adjusted to adapt to plastic pipes with different outer diameter dimensions. The thermoforming mechanism is provided with multiple groups according to plastic pipes with different outer diameter dimensions, and the thermoforming mechanism can be detachably installed on the frame.

[0024] With the above technical solution, external thread processing can be carried out on plastic pipes with different outer diameter dimensions, and the application range is wider.

[0025] Further, the positioning mechanism includes a lifting driving member and a clamping assembly connected to the lifting output end of the lifting driving member. The clamping assembly includes a bottom clamping roller and two end clamping rollers symmetrically arranged left and right above the bottom clamping roller. The bottom clamping roller is used for supporting the bottom of the plastic pipe, and the bottom clamping roller can move upward. The two end clamping rollers can move closer to each other synchronously when the bottom clamping roller moves upward to clamp the plastic pipe between the bottom clamping roller and the two end clamping rollers.

[0026] With the above technical solution, the clamping assembly can clamp the plastic pipe to be processed, and the lifting driving member can adjust the height of the clamped plastic pipe, so that the plastic pipe to be processed is coaxial with the support sleeve.

[0027] The beneficial effects of a plastic pipe interface external thread forming device provided by the present invention are as follows: The heating mechanism and the extrusion forming mechanism are integrated into an integral overall structure. After heating the plastic pipe, the plastic pipe can be immediately extruded and formed, which can avoid large deformations of the heated plastic pipe, and the quality of the formed thread is better. By setting an extrusion ring to extrude the plastic pipe in the thread cavity, the formed thread can be made more dense, and the structural strength of the threaded part in the plastic pipe can be improved. Description of the Drawings

[0028] Figure 1 It is a three-dimensional structural schematic diagram of a plastic pipe interface external thread forming device provided by the present invention; Figure 2 is Figure 1 the enlarged structural schematic diagram of part A in Figure 3 is Figure 1 the enlarged structural schematic diagram of part B in Figure 4 It is a front view of a plastic pipe interface external thread forming device provided by the present invention; Figure 5 It is a right view of a plastic pipe interface external thread forming device provided by the present invention; Figure 6 It is a top view of a plastic pipe interface external thread forming device provided by the present invention; Figure 7 It is a sectional view of a plastic pipe interface external thread forming device provided by the present invention; Figure 8 is Figure 7 the enlarged structural schematic diagram of part C in Figure 9 It is a structural schematic diagram of a positioning mechanism in a plastic pipe interface external thread forming device provided by the present invention; Figure 10 It is a three-dimensional structural schematic diagram of a thermoforming mechanism in a plastic pipe interface external thread forming device provided by the present invention; Figure 11 It is a sectional view of a thermoforming mechanism in a plastic pipe interface external thread forming device provided by the present invention Figure 1 ; Figure 12 It is a sectional view of a thermoforming mechanism in a plastic pipe interface external thread forming device provided by the present invention Figure 2 。

[0029] Description of the Reference Numerals: 1. Frame; 101. Connecting port; 102. Movable perforation; 2. Collection box; 3. Square housing; 301. Locking hole; 302. Feeding port; 4. Supporting plate; 401. First inclined plate section; 402. Second inclined plate section; 5. Chain; 6. Support block; 7. Sprocket; 8. Driving motor; 9. Support frame; 10. Cooling fan; 11. Movable frame; 12. Extrusion cylinder; 13. Support sleeve; 14. Forming module; 15. Moving block; 16. Connecting rod; 17. Support; 171. Support part; 18. Clamping arm; 19. Support plate; 20. Lifting cylinder; 21. Baffle; 22. Adjusting plate; 221. Third inclined plate section; 222. Straight plate section; 23. Support board; 24. Third elastic part; 25. Reeling cylinder; 26. Second connecting rod; 27. First elastic part; 28. Guide rod; 29. First connecting rod; 30. Bottom pressure roller; 31. End pressure roller; 32. Vertical pushing block; 321. Inclined side wall; 33. Clamping cylinder; 34. Heating rod; 35. Pressing block; 36. Driving ring; 37. Extrusion swing rod; 38. L-shaped connecting rod; 39. Transmission lead screw; 40. Transmission plate; 41. Extrusion ring; 42. Rocker arm; 43. Locking bolt. Detailed implementation mode

[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Those skilled in the art should know that the embodiments described below are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present invention.

[0031] The following is one of the embodiments of a plastic pipe interface external thread forming device provided by the present invention: As Figures 1 - 12 shown, a plastic pipe interface external thread forming device includes a frame 1, a material storage mechanism, a conveying mechanism, a thermoforming mechanism, and a positioning mechanism.

[0032] As Figure 1 、 Figure 2 shown, the frame 1 is arranged on the horizontal ground. The frame 1 is a rectangular box structure. The length direction of the frame 1 extends along the left and right directions. Both ends of the top side wall of the frame 1 are provided with connecting ports 101 communicating with the inner cavity of the frame 1. The top side wall of the frame 1 is also provided with a movable perforation 102 located between the two connecting ports 101. The front side wall of the frame 1 is detachably connected with a support frame 9 through connecting bolts. The position of the support frame 9 corresponds to the position of the movable perforation 102. A pull-out collection box 2 is provided at the bottom on the right side of the frame 1. The collection box 2 is vertically opposite to the connecting port 101 on the right side. The collection box 2 is used to collect the processed plastic pipes.

[0033] The storage mechanism includes a storage box, an adjustment component, a baffle component, and a support component.

[0034] As Figure 1 , Figure 7 , Figure 8 shown, the storage box includes a square outer shell 3 and a supporting plate 4. The top and bottom of the square outer shell 3 are both open. The square outer shell 3 is connected to the top of the frame 1 and is located above the communication port 101 on the left side of the frame 1. As Figure 1 , Figure 3 shown, a plurality of locking holes 301 surrounding a circle are provided on the rear side wall of the square outer shell 3, and a rectangular material passing opening 302 is provided at the bottom of the right side wall. As Figure 8 shown, a connecting rod two 26 extending forward and backward is further connected between the front and rear side walls of the square outer shell 3.

[0035] As Figure 7 , Figure 8 shown, the supporting plate 4 is located inside the square outer shell 3. The supporting plate 4 includes an inclined plate section one 401 and an inclined plate section two 402 connected in sequence from left to right. The left end of the inclined plate section one 401 is lower than the top surface of the square outer shell 3. Both the inclined plate section one 401 and the inclined plate section two 402 incline downward from left to right. The downward inclination amplitude of the inclined plate section two 402 is greater than that of the inclined plate section one 401. There is a gap between the right end of the inclined plate section two 402 and the right inner side wall of the square outer shell 3.

[0036] The space above the supporting plate 4 inside the square outer shell 3 forms a storage cavity for storing plastic pipes.

[0037] As Figure 7 , Figure 8 shown, the adjustment component includes an adjustment plate 22 and an adjustment plate driving component. Two adjustment plates 22 are symmetrically arranged front and back. The adjustment plate 22 includes an inclined plate section three 221 and a straight plate section 222 connected in sequence from left to right. The inclination angles of the inclined plate section three 221 and the inclined plate section two 402 are the same. The adjustment plate 22 is located on the lower right side of the inclined plate section two 402. A connecting rod one 29 extending forward and backward is connected between the tops of the two adjustment plates 22. The two adjustment plates 22 are connected into one body through the connecting rod one 29. The connecting rod one 29 is located on the right side of the above-mentioned connecting rod two 26. There is a gap between the straight plate section 222 and the right inner side wall of the square outer shell 3. The area at this gap forms a discharge cavity for discharging the plastic pipes downward.

[0038] As Figure 8 shown, a guide rod 28 extending left and right is vertically connected to the left side of the connecting rod one 29. The guide rod 28 slides left and right through the connecting rod two 26. An elastic member one 27 is connected between the connecting rod one 29 and the connecting rod two 26. The elastic member one 27 is a compression spring that can expand and contract in the left-right direction. The elastic member one 27 is sleeved outside the guide rod 28.

[0039] The adjusting plate driving member includes a connecting shaft, a wire winding cylinder 25 and a rocker arm 42.

[0040] The connecting shaft extends in the front-rear direction. The connecting shaft is rotatably installed on the square housing 3 and is located on the left side of the second connecting rod 26. The rear end of the connecting shaft extends to the outside of the square housing 3.

[0041] There are two wire winding cylinders 25. The two wire winding cylinders 25 are both sleeved on the outside of the connecting shaft in a non-rotating manner. The two wire winding cylinders 25 are arranged at intervals in the front-rear direction. A first pulling wire is wound on the wire winding cylinder 25. The head of the first pulling wire passes through the second connecting rod 26 and is connected to the first connecting rod 29.

[0042] As Figure 3 shown, the rocker arm 42 is connected to the rear end of the connecting shaft and is located outside the square housing 3. A locking bolt 43 is movably inserted through the end of the rocker arm 42 facing away from the rotating shaft in the front-rear direction. A second elastic member is connected between the locking bolt 43 and the rocker arm 42. The second elastic member is a tension spring that can expand and contract in the front-rear direction. When the second elastic member is in the natural state, the locking bolt 43 is inserted into the locking hole 301. By pulling the locking bolt 43 backward, the locking bolt 43 can be pulled out of the locking hole 301, so that the rocker arm 42 can rotate freely around the axis of the connecting shaft, and thus the locking bolt 43 can be inserted into any one of the locking holes 301.

[0043] When the rocker arm 42 is rotated clockwise, it can drive the connecting shaft and the wire winding cylinder 25 sleeved on the connecting shaft to rotate, so that the first pulling wire is wound on the wire winding cylinder 25. The first pulling wire drives the first connecting rod 29 and the two adjusting plates 22 to move leftward, increasing the width dimension of the discharging cavity, so that the discharging cavity can be suitable for plastic pipes with different diameter dimensions.

[0044] The baffle assembly includes two baffles 21 arranged at intervals in the front-rear direction. The two baffles 21 both extend vertically and are respectively opposite to the straight plate segments 222 of the above two adjusting plates 22 in the left-right direction. The two baffles 21 are both installed on the right side wall of the square housing 3 in a vertically guided and sliding manner. A pulley with an axis extending in the front-rear direction is rotatably installed on each of the front and rear sides of the right side wall of the square housing 3. The right end of the above first connecting rod 29 is connected with two second pulling wires. The two second pulling wires respectively bypass the two pulleys and are connected to the two baffles 21. When the above rocker arm 42 is rotated clockwise, it can drive the first connecting rod 29 to move leftward. The first connecting rod 29 drives the two baffles 21 to move upward through the second pulling wires. The above pulleys and second pulling wires are not shown in the figure.

[0045] The support assembly includes two support plates 23 arranged at intervals front and back. The left end of the support plate 23 is rotatably mounted on the square housing 3 around a rotation axis extending in the front and back directions. A third elastic member 24 is connected between the right end of the support plate 23 and the square housing 3. The third elastic member 24 is a tension spring. When the third elastic member 24 is in the natural state, the right end of the support plate 23 is higher than the left end. The two support plates 23 are respectively arranged below the two adjustment plates 22, and the support plate 23 is used to block the plastic pipe at the bottom in the discharge cavity.

[0046] As Figure 1 shown, the conveying mechanism includes two sets of conveying chain assemblies arranged symmetrically front and back.

[0047] The conveying chain assembly includes a sprocket 7, a chain 5 and a support block 6.

[0048] There are two sprockets 7 arranged at intervals left and right, both of which are rotatably mounted on the frame 1 around a rotation axis extending in the front and back directions. The sprocket 7 is located in the inner cavity of the frame 1.

[0049] The chain 5 is sleeved outside the two sprockets 7, and the part of the chain 5 between the tops of the two sprockets 7 is located above the top side wall of the frame 1.

[0050] There are multiple support blocks 6, which are connected to the chain 5 at equal intervals. The support block 6 is provided with a V-shaped groove with an opening facing away from the chain 5. The groove side walls on the left and right sides of the groove are of unequal height. When the support block 6 rotates with the chain 5 to be located above the frame 1, the left groove side wall of the groove is higher than the right groove side wall.

[0051] The front and rear opposite two support blocks 6 in the two sets of conveying chain assemblies are used to cooperate with each other to support the front and rear ends of the same plastic pipe.

[0052] The thermoforming mechanism includes a movable frame driving mechanism, a movable frame 11, a support sleeve 13, a forming die, an extrusion driving mechanism, a heating rod 34 and a compaction assembly.

[0053] As Figure 11 shown, the movable frame driving mechanism includes a driving motor 8 and a transmission lead screw 39. The driving motor 8 is fixedly installed on the support frame 9. The transmission lead screw 39 extends in the front and back directions and is rotatably installed on the support frame 9. The transmission lead screw 39 is in transmission connection with the driving motor 8 to be driven by the driving motor 8 to rotate.

[0054] As Figure 2 shown, the movable frame 11 is of a box structure and is detachably connected to the frame 1 through a connecting bolt. An air inlet is provided on the top side wall of the movable frame 11, and a cooling fan 10 is provided at the air inlet. As Figure 11As shown, the movable frame 11 is slidably mounted on the support frame 9 in the front-back direction. A transmission plate 40 in an L shape is connected to the bottom of the movable frame 11. The transmission plate 40 is spirally sleeved outside the transmission screw rod 39. When the driving motor 8 drives the transmission screw rod 39 to rotate, the transmission screw rod 39 drives the transmission plate 40 and the movable frame 11 to move in the front-back direction.

[0055] As Figure 2 , Figure 10 , Figure 11 , Figure 12 As shown, the axis of the support sleeve 13 extends in the front-back direction. The support sleeve 13 is vertically connected to the middle of the rear side wall of the movable frame 11. The rear end of the support sleeve 13 is conical. The inner cavity of the support sleeve 13 communicates with the inner cavity of the movable frame 11.

[0056] The forming die includes two forming modules 14 symmetrically arranged on the left and right sides of the support sleeve 13. Both forming modules 14 are slidably mounted on the movable frame 11 in the left-right direction. The cross section of the forming module 14 is in a semi-circular arc shape. Threaded protrusions in half sections are provided on the inner side wall of the forming module 14. The threaded protrusions on the two forming modules 14 are adapted to form a complete thread when the two forming modules 14 are in contact. When the two forming modules 14 are in contact, a threaded cavity for extruding and forming the interface end of the plastic pipe is jointly formed between them and the support sleeve 13.

[0057] As Figures 10 - 12 As shown, the extrusion driving mechanism includes an extrusion cylinder 12, a pressing block 35, a moving block 15 and a connecting rod 16.

[0058] The extrusion cylinder 12 is installed on the front side wall of the movable frame 11. The extrusion cylinder 12 has a driving output end that can move back and forth. The driving output end of the extrusion cylinder 12 is located in the inner cavity of the movable frame 11.

[0059] The pressing block 35 is connected to the driving output end of the extrusion cylinder 12 and can be driven by the extrusion cylinder 12 to move back and forth.

[0060] There are two moving blocks 15. The two moving blocks 15 are respectively connected to the two forming modules 14 and are located on the opposite sides of the two forming modules 14. The moving block 15 is slidably assembled on the rear side wall of the movable frame 11 in the left-right direction. The forming module 14 is slidably mounted on the movable frame 11 in the left-right direction through the moving block 15.

[0061] There are two connecting rods 16, which are arranged symmetrically left and right. The front ends of the two connecting rods 16 are hinged to the pressing block 35 around the rotation axis extending vertically, and the rear ends of the two connecting rods 16 are respectively hinged to the two moving blocks 15 around the rotation axis extending vertically. The spacing dimension between the front ends of the two connecting rods 16 is smaller than the spacing dimension between the rear ends of the two connecting rods 16. When the extrusion cylinder 12 drives the pressing block 35 to move backward, it can drive the two moving blocks 15 to move away from each other synchronously through the two connecting rods 16, that is, drive the two forming modules 14 to move away from each other synchronously. The connecting rod 16 is a telescopic rod, which can be stretched or compressed only when subjected to a certain amount of tensile or compressive force, and structures such as a gas spring or an elastic telescopic rod can be used.

[0062] The heating rod 34 extends in the front-rear direction, the heating rod 34 is connected to the rear side of the pressing block 35, the heating rod 34 is coaxial with the above-mentioned support sleeve 13, and when the extrusion cylinder 12 drives the pressing block 35 to move backward, it can drive the heating rod 34 to extend into the support sleeve 13.

[0063] As Figures 10 - 12 shown, the compaction assembly includes an extrusion ring 41, a driving ring 36, an extrusion swing rod 37 and an L-shaped connecting rod 38.

[0064] As Figure 11 , Figure 12 shown, the extrusion ring 41 is coaxially sleeved outside the support sleeve 13 and is located on the side of the forming die close to the movable frame 11. The driving ring 36 is located in the movable frame 11 and is coaxial with the extrusion ring 41. The driving ring 36 is connected to the extrusion ring 41 through a connecting rod passing through the rear side wall of the movable frame 11, and an elastic member four is connected between the driving ring 36 and the rear side wall of the movable frame 11.

[0065] There are two extrusion swing rods 37 arranged symmetrically left and right. The two extrusion swing rods 37 are both slidably hinged in the movable frame 11 in the up-down direction, and the top ends of the extrusion swing rods 37 are pressed on the driving ring 36.

[0066] There are two L-shaped connecting rods 38 arranged symmetrically left and right. The two L-shaped connecting rods 38 are respectively opposite to the two extrusion swing rods 37 in the front-rear direction. The L-shaped connecting rod 38 includes a horizontal rod section and a vertical rod section vertically connected to the front end of the horizontal rod section. The horizontal rod section is installed in the movable frame 11 in a guiding and sliding manner in the front-rear direction. The vertical rod section is located on the front side of the pressing block 35 and is stopped from each other in the front-rear direction with the pressing block 35. The rear end of the horizontal rod section is hinged to the bottom end of the corresponding extrusion swing rod 37. During the process that the extrusion cylinder 12 drives the pressing block 35 to move backward and drives the connecting rod 16 to elongate, the pressing block 35 can drive the L-shaped connecting rod 38 to move backward by pushing the vertical rod section, thereby driving the extrusion swing rod 37 to swing. The top end of the extrusion swing rod 37 presses the driving ring 36 to move backward, and the driving ring 36 drives the extrusion ring 41 to move backward. The extrusion ring 41 presses tightly on the end of the plastic pipe to compact the threaded part of the plastic pipe.

[0067] As shown Figure 7 in the figure, the positioning mechanism includes a lifting cylinder 20, a bracket, and a clamping assembly.

[0068] The lifting cylinder 20 is fixedly installed on the frame 1 and located in the inner cavity of the frame 1. The lifting cylinder 20 is vertically opposite to the movable perforation 102 on the frame 1.

[0069] As shown Figure 6 and Figure 7 in the figure, the bracket includes a support plate 19 and a support 17. The support plate 19 extends horizontally and is connected to the lifting output end of the lifting cylinder 20. There are two supports 17, and both of the two supports 17 are connected to the top of the support plate 19 and are distributed at the front and rear ends of the support plate 19. As shown Figure 7 and Figure 9 in the figure, the inside of the support 17 is hollow and the top is open. The top of the support 17 is also provided with a support portion 171, and a V-shaped support groove is provided on the support portion 171.

[0070] The clamping assembly includes a clamping cylinder 33, a vertical push block 32, and a clamping arm 18.

[0071] As shown Figure 9 in the figure, the clamping cylinder 33 is installed on the bottom side wall of the support 17, and the clamping cylinder 33 has a driving output end that can move up and down.

[0072] The vertical push block 32 has two obliquely side walls 321 arranged symmetrically left and right. The vertical push block 32 is installed in the inner cavity of the support 17 in a vertically guided and sliding manner, and a bottom pressure roller 30 is connected to the top of the vertical push block 32.

[0073] There are two groups of clamping arms 18, and the two clamping arms 18 are symmetrically arranged on the left and right sides of the vertical push block 32. The clamping arm 18 includes two swing rods connected together and forming an opening facing the bottom pressure roller 30. An obtuse angle is formed between the two swing rods. The connecting area of the two swing rods is hinged on the support 17 around the rotation axis extending in the front and rear directions, and a torsion spring is connected between the two swing rods and the support 17. An end pressure roller 31 is connected to the opposite end of each of the two swing rods.

[0074] The two end pressure rollers 31 at the bottom in the two groups of clamping arms 18 are respectively pressed against the two obliquely side walls 321 of the vertical push block 32. When the clamping cylinder 33 drives the vertical push block 32 to move upward, it drives the bottom pressure roller 30 to move upward, and drives the two clamping arms 18 to swing through the two obliquely side walls 321, so that the tops of the two clamping arms 18 approach each other, thereby clamping the plastic pipe by the bottom pressure roller 30 and the end pressure rollers 31 at the tops of the two clamping arms 18.

[0075] When the present invention is in use, first place the plastic pipe to be processed in the storage cavity. The plastic pipe moves along the inclined plate section 1 401, the inclined plate section 2 402 and the inclined plate section 3 221 in the storage cavity towards the discharge cavity and accumulates in the discharge cavity. The plastic pipe at the bottom is supported by two support plates 23.

[0076] After that, start the conveying mechanism. The chain 5 starts to rotate clockwise. When the support block 6 on the chain 5 moves to the position of the plastic pipe supported by the support plate 23, the left side wall of the groove in the support block 6 pushes the plastic pipe to move to the right. The plastic pipe pushes the support plate 23 to swing downward, and the interval between the support plate 23 and the baffle 21 increases, so that the plastic pipe can leave the discharge cavity and fall into the groove on the support block 6. Then the plastic pipe is driven by the support block 6 to continue moving to the right.

[0077] When the plastic pipe moves to the movable perforation 102, the lifting cylinder 20 drives the bracket to move upward. The plastic pipe falls into the support groove on the support part 171 at the top of the support 17, and is lifted upward by the support part 171 and separated from the support block 6. Then the clamping cylinder 33 drives the vertical push block 32 to move upward, driving the bottom pressing roller 30 to move upward. The two end pressing rollers 31 at the top move closer to each other to clamp the plastic pipe supported by the support part 171. After being clamped, the plastic pipe is coaxial with the support sleeve 13.

[0078] After that, start the driving motor 8. The driving motor 8 drives the movable frame 11 to move backward. The support sleeve 13 is inserted into the interface end of the plastic pipe from front to back to support the plastic pipe. At this time, the two forming modules 14 are kept away from each other. The heating rod 34 is located inside the support sleeve 13. The heating rod 34 heats the interface end of the plastic pipe to soften the plastic pipe. After the plastic pipe is softened, start the extrusion cylinder 12. The extrusion cylinder 12 drives the pressing block 35 to move forward. The pressing block 35 drives two moving blocks 15 to move closer to each other through the connecting rod 16. The two forming modules 14 move closer to each other and press on the interface end of the plastic pipe to press an external thread on the plastic pipe. At the same time, the pressing block 35 drives the heating rod 34 to move forward and leave the inner cavity of the support sleeve 13.

[0079] After the two forming modules 14 are in contact with each other, the extrusion cylinder 12 can pull the connecting rod 16 to elongate, so as to drive the pressing block 35 to continue moving forward. When the pressing block 35 continues to move forward, it drives the L-shaped connecting rod 38 to move forward. The L-shaped connecting rod 38 drives the extrusion swing rod 37 to swing, so that the top end of the extrusion swing rod 37 presses on the driving ring 36. The driving ring 36 drives the extrusion ring 41 to move backward to press the threaded section of the plastic pipe more densely.

[0080] Then, the extrusion cylinder 12 is controlled to drive the pressing block 35 to move backward, and the pressing block 35 drives the two forming modules 14 to move away from each other through the connecting rod 16, loosening the plastic tube after thread forming, and then starting the driving motor 8 to control the movable frame 11 to move forward, so that the supporting sleeve 13 is separated from the plastic tube.

[0081] The clamping cylinder 33 drives the vertical push block 32 to move downward to loosen the plastic tube, and the loosened plastic tube falls into the support groove. Then the lifting cylinder 20 drives the bracket to move downward, driving the plastic tube to fall into the groove on the support block 6 again. The lifting cylinder 20 drives the bracket and the clamping assembly to move into the inner cavity of the frame 1. The support block 6 supports the processed plastic tube and continues to move to the right, and transports the processed plastic tube to the connecting port 101 located on the right side of the frame 1. The processed plastic tube falls into the collection box 2 at the bottom of the frame 1 from the connecting port 101.

[0082] When it is necessary to process external threads on plastic pipes of different diameters, the locking bolt 43 can be pulled out from the locking hole 301, and then the rocker arm 42 can be rotated to adjust the width of the discharge cavity to match the diameter of the new plastic pipe, and at the same time, the baffle 21 is driven to move so that the height of the bottom end of the baffle 21 matches the diameter of the new plastic pipe, so as to facilitate the new plastic pipe to be pulled out of the discharge cavity. At the same time, the thermoforming mechanism is removed from the frame 1 as a whole by screwing the connecting bolts, and the thermoforming mechanism is replaced as a whole, so that the size of the supporting sleeve 13 and the forming mold in the replaced thermoforming mechanism matches the size of the new plastic pipe, so that the forming device can process plastic pipes of different sizes.

[0083] The present invention provides a support sleeve 13 to support the plastic pipe, and the connection between the heating link and the extrusion molding link of the plastic pipe is more coherent, which can improve production efficiency and avoid significant deformation of the plastic pipe after heating and softening. The thread molding quality of the present invention is better and the quality is better.

Claims

1. An external thread forming device for a plastic pipe interface, comprising a frame, on which a material storage mechanism for storing plastic pipes and a conveying mechanism for conveying the plastic pipes to move from left to right are provided, characterized in that, The frame is also equipped with a thermoforming mechanism and a positioning mechanism. The thermoforming mechanism includes: The supporting sleeve has an axis extending in the front-to-back direction, can move forward and backward on the frame, and is used to be inserted into the plastic pipe to support the plastic pipe; The heating rod is coaxial with the supporting sleeve and can move forward and backward on the frame, and is used to be inserted into the supporting sleeve to heat the plastic pipe; The molding die comprises two molding modules with semicircular cross sections symmetrically arranged on the left and right sides of the supporting sleeve, wherein the inner side walls of the two molding modules are provided with half-segment thread protrusions, and the two molding modules can synchronously approach or move away from each other in the left and right directions. When the two molding modules are in contact with each other, they can cooperate with the supporting sleeve to enclose a threaded cavity for extruding the interface end of the plastic pipe; The positioning mechanism is used to clamp the plastic tube delivered to the thermoforming mechanism and move the plastic tube so that the plastic tube and the supporting sleeve are kept coaxial.

2. The external thread forming device for the plastic pipe interface according to claim 1, wherein The thermoforming mechanism also includes a movable frame and a movable frame driving mechanism. The supporting sleeve is fixedly connected to the movable frame. Two forming modules are slidably installed on the movable frame with left and right guides. The movable frame can be driven by the movable frame driving mechanism to move along the front and back directions toward the plastic tube clamped by the positioning mechanism, so that the supporting sleeve is inserted into the plastic tube.

3. The plastic pipe interface external thread forming device according to claim 2, characterized in that, An extrusion driving mechanism is provided on the movable frame, and the extrusion driving mechanism includes an extrusion cylinder, a pressing block, a moving block and two connecting rods. The extrusion cylinder has a driving output end that can move forward and backward. The pressing block is connected to the driving output end of the extrusion cylinder. The pressing block is located between the extrusion cylinder and the forming mold. There are two moving blocks, and the two moving blocks are respectively connected to the two forming modules. The two moving blocks are both guided and slidably installed on the movable frame along the left and right directions. The two connecting rods are symmetrically arranged on the left and right sides of the supporting sleeve. One end of the connecting rod is hinged on the pressing block around a vertically extending rotation axis, and the other end is hinged on the moving block on the corresponding side around a vertically extending rotation axis. The spacing size of the hinge points of the two connecting rods on the pressing block is smaller than the spacing size of the hinge points of the two connecting rods on the two moving blocks.

4. The plastic pipe interface external thread forming device according to claim 3, characterized in that, The heating rod is connected to the pressing block, and when the extrusion cylinder drives the pressing block to move toward the forming die, the heating rod can be driven to insert into the supporting sleeve.

5. A plastic pipe interface external thread forming device according to claim 4, characterized in that, An extrusion ring that can move forward and backward is provided on the movable frame. The extrusion ring is mounted on the supporting sleeve. The extrusion ring is located on the side of the forming mold close to the movable frame and is opposite to the front and back of the threaded cavity. The pull rod is a telescopic rod. The pull rod can be driven by the extrusion cylinder and lengthened after the two forming modules are abutted, so that the pressure block can be driven by the extrusion cylinder after the two forming modules are abutted and continue to move back to the forming mold. The pressure block is connected with the extrusion ring in a transmission connection, and the extrusion ring can be driven by the pressure block moving back to the forming mold to move toward the threaded cavity.

6. A plastic pipe interface external thread forming device according to any one of claims 2-5, characterized in that, The movable frame is a box structure, the support sleeve is connected to the outer wall of the movable frame and communicates with the inner cavity of the movable frame, an air inlet is provided on the side wall of the movable frame, a cooling fan is installed at the air inlet, and the cooling fan can blow air toward the inner cavity of the movable frame through the air inlet.

7. A plastic pipe interface external thread forming device according to any one of claims 1-5, characterized in that, The conveying mechanism comprises two groups of conveying chain components arranged symmetrically front and back. The conveying chain components comprise chains and supporting blocks connected to the chains. The supporting blocks are provided with grooves with openings facing away from the chains for placing plastic pipes.

8. A plastic pipe interface external thread forming device according to claim 7, characterized in that, The material storage mechanism includes a material storage box. A material storage cavity is provided inside the material storage box. The bottom of the material storage cavity communicates with a vertically extending discharge cavity for storing multiple plastic pipes stacked one above the other. The width dimension of the discharge cavity is adapted to the outer diameter dimension of the plastic pipe to be processed. A support plate is provided at the bottom of the discharge cavity for supporting below the lowermost plastic pipe in the discharge cavity. The left end of the support plate is elastically hinged to the frame about a rotation axis extending in the front-rear direction. The right end of the support plate is higher than the left end. The left side wall of the groove in the support block located on the upper half of the chain is higher than the right side wall. When the support block moves to the right, the left side wall of the groove can push the lowermost plastic pipe to the right and push the support plate to swing downward, so as to pull out the plastic pipe from the bottom of the discharge cavity and drop it into the groove.

9. A plastic pipe interface external thread forming device according to claim 8, characterized in that, The width dimension of the discharge cavity can be adjusted to adapt to plastic pipes with different outer diameter dimensions. Multiple groups of thermoforming mechanisms are provided according to the plastic pipes with different outer diameter dimensions. The thermoforming mechanism can be detachably installed on the frame.

10. A plastic pipe interface external thread forming device according to any one of claims 1-5, characterized in that, The positioning mechanism includes a lifting driving member and a clamping assembly connected to the lifting output end of the lifting driving member. The clamping assembly includes a bottom clamping roller and two end clamping rollers symmetrically arranged on the upper side of the bottom clamping roller. The bottom clamping roller is used for supporting the bottom of the plastic pipe. The bottom clamping roller can move upward. The two end clamping rollers can move closer to each other synchronously when the bottom clamping roller moves upward, so as to clamp the plastic pipe between the bottom clamping roller and the two end clamping rollers.

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