An automated welding device for high-precision PVC pipes

Abstract

The present invention belongs to the field of PVC pipe connection equipment and relates to a high-precision automatic welding device for PVC pipes. The device includes a driving ring that hugs the outer wall of the pipe. The driving ring is connected to a hot air pipe, and its air outlet is located between the pipe weld and the PVC welding strip. The driving ring is provided with a welding assembly through a connecting rod mechanism. The welding assembly includes a mounting base plate and a rolling mechanism at the rear. There are two groups of hot air pipes located on both sides of the weld, and the air outlets are in a J shape. The rolling mechanism includes rolling balls that can roll the PVC welding strip. The connecting rod mechanism is in the shape of a parallelogram and is provided with a return spring and a damping rod. The rolling mechanism also has a lifting component that can control the lifting or lowering of the rolling balls. The driving ring is composed of a seat ring and swinging rings hinged on both sides, and the driving roller wheels can adapt to different pipe diameters. This device can automatically rotate uniformly along the weld, realize uniform heating of the weld, ensure uniform melting and fusion of the contact surfaces, avoid defects such as false welding, and improve the welding precision.

Description

Technical Field

[0001] The present invention belongs to the field of PVC pipe connection equipment, and particularly relates to a high-precision automatic welding device for PVC pipes. Background Art

[0002] PVC (polyvinyl chloride) pipes are widely used in municipal engineering, chemical industry, building drainage, agricultural irrigation and other fields due to their advantages such as corrosion resistance, light weight and low cost. With the expansion of project scale and technological upgrading, the reliability requirements for pipeline systems are increasing day by day. In scenarios such as high-pressure transmission, large-diameter (above DN100) installation, high-temperature medium transmission, concealed works and special chemical environments, the traditional adhesive connection method is prone to problems such as glue aging and uneven bonding surfaces, resulting in risks of leakage or fracture. Therefore, hot melt welding has gradually become the preferred connection technology in high-demand scenarios.

[0003] However, traditional hot melt welding relies on manual operation and has extremely high requirements for welder experience. During the welding process, parameters such as the heating temperature of the pipe end face, melting time, and extrusion pressure of the PVC welding sheet are difficult to stably control, easily leading to defects such as false welding, over-melting or misalignment on the fusion surface. Moreover, the pipes are basically positioned before construction, and the reserved operation positions may not be convenient for personnel to enter, causing further interference to the construction. Summary of the Invention

[0004] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a high-precision automatic welding device for PVC pipes, which can automatically rotate uniformly along the butt weld of the pipe, realize uniform heating of the weld, ensure uniform melting of the contact surface between the PVC welding sheet and the pipe, cooperate with the pressing of the PVC welding material to ensure uniform fusion of the contact surface, avoid defects such as false welding, over-melting and misalignment, and improve the welding precision.

[0005] The specific technical solution adopted by the present invention is as follows:

[0006] A high-precision automatic welding device for PVC pipes includes a driving ring clamped on the outer wall of the pipe. A hot air pipe is connected to the driving ring, and the air outlet of the hot air pipe is located between the pipe weld and the PVC welding sheet. A welding assembly is arranged on the driving ring by means of a connecting rod mechanism. The welding assembly includes a mounting base plate and a rolling pressure mechanism arranged at the rear side of the mounting base plate. Two groups of hot air pipes are provided and are respectively located on both sides of the pipe weld. The air outlet of the hot air pipe is in a J-shaped structure bent towards the midline of the pipe weld. The rolling pressure mechanism includes a rolling pressure ball, and the rolling pressure ball is located behind the hot air pipe and rolls and presses the PVC welding sheet.

[0007] The described link mechanism includes a first connecting piece and a second connecting piece. A fixed arm is provided on the driving ring. The first connecting piece, the second connecting piece, the fixed arm, and the mounting base plate form a parallelogram link structure. A return spring is further provided between the first connecting piece and the fixed arm, and a damping rod is coaxially sleeved inside the return spring.

[0008] The described rolling mechanism includes a rolling seat fixed to the mounting base plate. A horizontal rolling slide rail is provided on the rolling seat, and the direction of the rolling slide rail is perpendicular to the moving direction of the welding assembly. A first slider and a second slider are provided on the rolling slide rail. A rolling transmission belt driven by a rolling motor is further provided on the rolling seat. The rolling transmission belt forms a closed-loop structure by means of a reversing roller. The first slider and the second slider are respectively connected to the rolling transmission belt on the inlet and outlet sides of the reversing roller. Rolling balls are respectively provided at the lower ends of the first slider and the second slider. The first slider and the second slider have a freedom of movement towards or away from each other along the rolling slide rail driven by the rolling motor.

[0009] The described rolling mechanism further includes a lifting assembly. The lifting assembly includes a profiling guide rail provided on the rolling seat, and two groups of lifting seats respectively provided on the first slider and the second slider. The lifting seats form a freedom of sliding in the vertical direction by means of vertical through grooves provided on the first slider and the second slider. Pressing springs are respectively provided between the lifting seats and the first slider and the second slider. The lifting seats are further provided with profiling insertion rods inserted into the profiling guide rail. When the lifting seats move with the first slider or the second slider, the rolling balls are lifted or lowered along the profiling guide rail by means of the profiling insertion rods.

[0010] A groove body in a horizontally arranged D-shaped structure is provided on the profiling guide rail. The arched section of the groove body is higher than the straight section. When the profiling insertion rod is located in the straight section, the rolling ball is in rolling contact with the PVC welding sheet. When the profiling insertion rod is located in the arched section, the rolling ball is separated from the PVC welding sheet. A swing piece is provided at the intersection of the inner side of the weld seam, the arched section and the straight section of the groove body. The swing piece faces the inner side of the weld seam and hangs down by gravity to close the straight section.

[0011] The described driving ring includes a seat ring and swing rings hinged on both sides of the seat ring. A group of driving roller wheels are respectively provided inside the seat ring and the swing rings. The freedoms of the swing rings on both sides are detachably connected by means of bolts.

[0012] Two driving roller wheels are in a group. The driving roller wheel includes a wheel seat for fixing to the side wall of the seat ring or the swing ring, and swing arms hinged on both sides of the wheel seat. A wheel body driven by a driving motor is provided on the swing arms, and a tension spring is provided between the swing arms.

[0013] A connecting rod is arranged between the wheel seats of the driving roller wheels of the same group, and the connecting rod is located between the hinge point of the swing arm and the tie spring.

[0014] The beneficial effects of the present invention are:

[0015] The present invention adopts

[0016] The present invention can automatically rotate at a uniform speed along the butt weld of the pipeline to achieve uniform heating of the weld, ensure uniform melting of the contact surface between the PVC welding piece and the pipeline, and cooperate with the pressing of the PVC welding material to ensure uniform fusion of the contact surface, avoid false welding, over-melting and misalignment defects, and improve welding accuracy.

[0017] During the welding process, the hot air pipe is driven by the driving ring and the position of the hot air pipe is stable. As long as the driving ring rotates at a constant speed, a stable weld hot melting effect can be obtained, thereby improving the welding quality and accuracy.

[0018] The welding assembly is pressed above the weld with the help of a parallelogram linkage mechanism, and the pressing force is maintained by a return spring. At the same time, the vibration of the return spring is reduced with the help of a damping rod, thereby improving the rolling accuracy of the roller ball after welding.

[0019] Due to the provided pressing spring, the lifting seat has a downward pressing tendency, which ensures that the roller ball moves in a straight line, avoids excessive pressure from squeezing the molten PVC material out of the weld, and ensures that the weld is neat.

[0020] The air outlet of the hot air duct is a J-shaped structure, which plays a supporting role along the side wall of the PVC pipe. The pressure provided by the return spring is sufficient to ensure that the air outlet is close to the side wall of the pipe, ensuring that the roller ball does not sink too deeply when rolling over the melted PVC material area, preventing the PVC pipe from deforming and improving the welding quality.

[0021] By setting the contoured guide rail, the rolling ball forms a reciprocating zigzag trajectory, and maintains the direction from outside to inside during rolling, so that the edge of the weld is pressed first, avoiding the outflow of the more melted PVC material inside, which helps to force the molten material to flow to the interface gap where the two pipes are connected, thereby improving the sealing effect.

[0022] The J-shaped hot air duct outlet is set so that the hot air duct is inserted directly under the PVC welding sheet. The distance between the hot air duct outlet and the roller ball is equal to the distance between the two returns of the roller ball, so that the hot air from the hot air duct flows out along the inclined weld formed by the last roller ball rolling, providing a relatively parallel melting path for the next roller ball rolling, avoiding heat waste.

[0023] The driving ring is opened with the help of a swing ring, so that the driving ring can be easily sleeved on the pipeline. When it needs to be moved, the bolts can be loosened for convenient disassembly.

[0024] By means of the provided connecting rod, it is possible to prevent the pulling spring from swinging too much on both sides, prevent the pulling spring from bypassing the hinge point of the swing arm, and ensure that the swing arm can be smoothly reset.

[0025] By means of the pulling spring, the wheel body located at the end of the swing arm can swing, thereby improving the adaptability of the inner diameter of the driving ring. With the drive of the driving motor, the wheel body can rotate along the side wall of the pipeline, so as to ensure that the driving ring rotates around the axis of the pipeline. In cooperation with the forward and reverse rotation of the roller pressing motor, an automatic welding process can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic structural diagram of the present invention;

[0027] Figure 2 is Figure 1 a schematic diagram in the right direction of the driving ring in

[0028] Figure 3 is a schematic structural diagram when the welding assembly is matched with the weld seam;

[0029] Figure 4 is Figure 3 a schematic diagram in the right direction;

[0030] Figure 5 is a schematic diagram of the driving roller;

[0031] Figure 6 is a schematic diagram of the link mechanism;

[0032] Figure 7 is a schematic diagram of the profiling guide rail;

[0033] Figure 8 is a schematic diagram of the trajectory of the roller pressing ball;

[0034] In the drawings, 1, driving ring; 2, hot air pipe; 3, PVC welding strip; 4, mounting base plate; 5, roller pressing ball; 6, first connecting piece; 7, second connecting piece; 8, fixed arm; 9, return spring; 10, roller pressing seat; 11, roller pressing slide rail; 12, first slider; 13, second slider; 14, roller pressing motor; 15, roller pressing transmission belt; 16, reversing roller; 17, profiling guide rail; 18, lifting seat; 19, vertical through groove; 20, profiling insertion rod; 21, swing piece; 101, seat ring; 102, swing ring; 22, wheel seat; 23, swing arm; 24, wheel body; 25, pulling spring; 26, connecting rod; 27, pressing spring. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] The present invention will be further described below in conjunction with the drawings and specific embodiments:

[0036] The specific embodiments are as Figure 1 and Figure 2 ,Figure 3 As shown in the figure, the present invention is a high-precision automatic welding device for PVC pipes, including a driving ring 1 clamped on the outer wall of the pipe. A hot air pipe 2 is connected to the driving ring 1. The air outlet of the hot air pipe 2 is located between the pipe weld and the PVC welding strip 3. A welding assembly is arranged on the driving ring 1 by means of a connecting rod mechanism. The welding assembly includes a mounting base plate 4 and a rolling mechanism arranged at the rear side of the mounting base plate 4. Two groups of the hot air pipes 2 are arranged and are respectively located on both sides of the pipe weld. The air outlet of the hot air pipe 2 is in a J-shaped structure bent towards the center line of the pipe weld. The rolling mechanism includes a rolling ball 5. The rolling ball 5 is located at the rear side of the hot air pipe 2 and rolls the PVC welding strip 3.

[0037] When the present invention is in use, the driving ring 1 is clamped on the outer wall of the pipe, the welding assembly is placed on the weld to be processed, and the PVC welding strip 3 of appropriate length is pre-cut by personnel. By the rotation of the driving ring 1 along the outer wall of the pipe, the welding assembly is driven to rotate along the weld, so that the PVC welding strip 3 is welded and fixed with the weld of the pipe. During the welding process, it is driven by the driving ring 1. The hot air pipe 2 is connected to a hot air blower, and the air outlet position is stable. As long as the driving ring 1 rotates at a constant speed, a stable hot melting effect of the weld can be obtained, thereby improving the welding quality and precision.

[0038] Further, as Figure 6 shown, the connecting rod mechanism includes a first connecting piece 6 and a second connecting piece 7. A fixed arm 8 is arranged on the driving ring 1. The first connecting piece 6, the second connecting piece 7, the fixed arm 8 and the mounting base plate 4 enclose a parallelogram connecting rod structure. A return spring 9 is further arranged between the first connecting piece 6 and the fixed arm 8. A damping rod is coaxially sleeved in the return spring 9.

[0039] As Figure 6 and Figure 4 shown, when the driving ring 1 is fixed on the pipe, the welding assembly is pressed above the weld by means of the parallelogram connecting rod mechanism, the pressing force is maintained by the return spring 9, and at the same time, the tremor degree of the return spring 9 is reduced by means of the damping rod, improving the rolling precision of the rolling ball 5 after welding.

[0040] Further, as Figure 3 and Figure 4As shown in the figure, the roll pressing mechanism includes a roll pressing seat 10 fixed to the mounting base plate 4. A horizontal roll pressing slide rail 11 is provided on the roll pressing seat 10. The direction of the roll pressing slide rail 11 is perpendicular to the moving direction of the welding assembly. A first slider 12 and a second slider 13 are provided on the roll pressing slide rail 11. A roll pressing transmission belt 15 driven by a roll pressing motor 14 is also provided on the roll pressing seat 10. The roll pressing transmission belt 15 forms a closed-loop structure by means of a reversing roller 16. The first slider 12 and the second slider 13 are respectively connected to the roll pressing transmission belt 15 on the inlet and outlet sides of the reversing roller 16. Roll pressing balls 5 are respectively provided at the lower ends of the first slider 12 and the second slider 13. The first slider 12 and the second slider 13 have a degree of freedom of moving towards or away from each other along the roll pressing slide rail 11 under the drive of the roll pressing motor 14.

[0041] The first slider 12 and the second slider 13 are respectively connected to the inlet side and the outlet side of the roll pressing transmission belt 15. When the roll pressing motor 14 rotates clockwise, as Figure 4 shown in the figure, at this time, the first slider 12 moves to the right, the second slider 13 moves to the left, and the two sliders close; when the roll pressing motor 14 rotates counterclockwise, at this time, the first slider 12 moves to the left, the second slider 13 moves to the right, and the two sliders open. Thus, the roll pressing balls 5 formed by the bull's-eye universal balls repeatedly roll press the PVC welding sheet 3. Due to the rotation of the driving ring 1, the contact surface between the PVC welding sheet 3 and the pipeline has been melted by the hot air pipe 2 at this time, thereby realizing the welding operation.

[0042] Furthermore, the roll pressing mechanism further includes a lifting assembly. The lifting assembly includes a profiling guide rail 17 provided on the roll pressing seat 10 and two groups of lifting seats 18 respectively provided on the first slider 12 and the second slider 13. The lifting seats 18 form a degree of freedom of sliding in the vertical direction by means of vertical through grooves 19 provided on the first slider 12 and the second slider 13. Pressing springs 27 are respectively provided between the lifting seats 18 and the first slider 12 and the second slider 13. The lifting seats 18 are also provided with profiling insertion rods 20 inserted into the profiling guide rail 17. When the lifting seats 18 move with the first slider 12 or the second slider 13, the roll pressing balls 5 are lifted or lowered along the profiling guide rail 17 by means of the profiling insertion rods 20.

[0043] A groove body with a horizontally arranged D-shaped structure is provided on the profiling guide rail 17. The arched section of the groove body is higher than the straight section. When the profiling insertion rod 20 is located in the straight section, the roll pressing ball 5 is in rolling contact with the PVC welding sheet 3. When the profiling insertion rod 20 is located in the arched section, the roll pressing ball 5 is out of contact with the PVC welding sheet 3. A swing piece 21 is provided at the intersection of the arched section and the straight section inside the weld of the groove body. The swing piece 21 faces the inside of the weld and hangs down by gravity to close the straight section.

[0044] Due to the provided pressing spring 27, the lifting seat 18 has a downward pressing tendency. Therefore, when the first slider 12 and the second slider 13 are opened to both ends, the profiling rod 20 enters the straight section. Then, when the two sliders are closed by the roller motor 14, the profiling rod 20 still moves along the straight section, thereby ensuring that the roller ball 5 moves in a straight line, avoiding excessive pressure from squeezing the molten PVC material out of the weld, and ensuring that the weld is neat. The air outlet of the hot air pipe 2 is a J-shaped structure, such as Figure 3 As shown, it plays a supporting role along the side wall of the PVC pipe, and the pressure provided by the return spring 9 is sufficient to ensure that the air outlet is close to the side wall of the pipe, and to ensure that the roller ball 5 does not sink too deeply when rolling over the melted PVC material area, thereby preventing the PVC pipe from deforming and improving the welding quality.

[0045] When Figure 7 As shown, when the profiling rod 20 moves to the end of one side inside the weld, the profiling rod 20 pushes the swinging piece 21 to enter the end. As the rolling motor 14 reverses, the two sliders reopen. At this time, the swinging piece 21 has swung under its own gravity to close the straight section, allowing the profiling rod 20 to slide into the arched section of the D-shaped structure groove, thereby lifting the rolling ball 5 and avoiding return crushing.

[0046] like Figure 8 As shown, by setting the contoured guide rail 17, the rolling ball 5 forms a reciprocating broken line trajectory, wherein the solid line portion is the trajectory of the rolling ball 5 actually rolling in the straight section, and the dotted line portion is the trajectory of the rolling ball 5 not actually rolling in the arched section, and the end of the trajectory extends to the outside of the weld. When rolling, the direction from outside to inside is maintained, so that the edge of the weld is pressed first to avoid the outflow of the more melted PVC material inside, which helps to force the molten material to flow to the interface gap where the two pipes are butt-jointed, thereby improving the sealing effect.

[0047] Moreover, due to the J-shaped arrangement of the air outlet of the hot air pipe 2, the hot air pipe 2 is inserted directly under the PVC welding piece 3. Figure 8 As shown, the distance L between the air outlet of the hot air pipe 2 and the rolling ball 5 is equal to the distance L between the two turns of the rolling ball 5, so that the hot air of the hot air pipe 2 flows out along the inclined weld formed by the last rolling of the rolling ball 5, providing a relatively parallel melting path for the next rolling of the rolling ball 5, avoiding heat waste.

[0048] Furthermore, the driving ring 1 includes a seat ring 101 and swing rings 102 hinged on both sides of the seat ring 101. A set of driving rollers are respectively arranged in the seat ring 101 and the swing ring 102. The swing rings 102 on both sides are detachably connected by bolts. The driving ring 1 is opened by means of the swing ring 102, so that the driving ring 1 can be easily mounted on the pipeline. When displacement is required, the bolts can be loosened for convenient disassembly.

[0049] Further, two driving roller wheels form a group. The driving roller wheel includes a wheel seat 22 for fixing to the side wall of the seat ring 101 or the swing ring 102, and swing arms 23 hinged on both sides of the wheel seat 22. A wheel body 24 driven by a driving motor is arranged on the swing arm 23, wherein the driving motor is seen in Figure 5 the side of the swing arm 23. A tension spring 25 is arranged between the swing arms 23. A connecting rod 26 is arranged between the wheel seats 22 of the driving roller wheels in the same group. The connecting rod 26 is located between the hinge point of the swing arm 23 and the tension spring 25. By means of the arranged connecting rod 26, the tension spring 25 is prevented from having too large an opening angle between the swing arms 23 on both sides, and the tension spring 25 is prevented from bypassing the hinge point of the swing arm 23, ensuring that the swing arm 23 can be reset smoothly.

[0050] By means of the tension spring 25, the wheel body 24 located at the end of the swing arm 23 can swing, thereby improving the adaptability of the inner diameter of the driving ring 1. Driven by the driving motor, the wheel body 24 can rotate along the side wall of the pipeline, thereby ensuring that the driving ring 1 rotates around the axis of the pipeline. In cooperation with the forward and reverse rotation of the roller pressing motor 14, the automatic welding process of the trajectory as Figure 8 shown is realized.

Claims

1. A high-precision PVC pipe automatic welding device, comprising a driving ring (1) clamped on the outer wall of the pipe, a hot air pipe (2) connected to the driving ring (1), an air outlet of the hot air pipe (2) located between the pipe weld and the PVC welding piece (3), characterized in that: The driving ring (1) is provided with a welding assembly by means of a connecting rod mechanism, the welding assembly comprising a mounting base plate (4) and a rolling mechanism arranged at the rear side of the mounting base plate (4), the hot air pipe (2) is provided with two groups and is respectively located at both sides of the pipe weld, the air outlet of the hot air pipe (2) is in a J-shaped structure bent toward the center line of the pipe weld, the rolling mechanism comprises a rolling ball (5), the rolling ball (5) is located at the rear side of the hot air pipe (2) and rolls the PVC welding sheet (3); The rolling mechanism comprises a rolling seat (10) fixed to the mounting base plate (4), the rolling seat (10) being provided with a transverse rolling slide rail (11), the direction of the rolling slide rail (11) being perpendicular to the moving direction of the welding assembly, the rolling slide rail (11) being provided with a first slider (12) and a second slider (13), the rolling seat (10) being further provided with a rolling transmission belt (15) driven by a rolling motor (14), the rolling transmission belt (15) 15) A closed loop structure is formed by means of a reversing roller (16), the first slider (12) and the second slider (13) are respectively connected to the roller drive belt (15) on the inlet and outlet sides of the reversing roller (16), and roller balls (5) are respectively provided at the lower ends of the first slider (12) and the second slider (13). The first slider (12) and the second slider (13) have the freedom of movement towards or away from each other along the roller slide rail (11) driven by a roller motor (14).

2. A high-precision PVC pipe automatic welding device according to claim 1, characterized in that: The connecting rod mechanism comprises a first connecting piece (6) and a second connecting piece (7); a fixed arm (8) is arranged on the driving ring (1); the first connecting piece (6), the second connecting piece (7), the fixed arm (8) and the mounting base plate (4) form a parallelogram connecting rod structure; a return spring (9) is further arranged between the first connecting piece (6) and the fixed arm (8); a damping rod is coaxially sleeved in the return spring (9).

3. The high-precision PVC pipe automatic welding device according to claim 1 is characterized in that: The rolling mechanism also includes a lifting component, which includes a contoured guide rail (17) arranged on the rolling seat (10), and two groups of lifting seats (18) respectively arranged on the first slider (12) and the second slider (13). The lifting seat (18) forms a degree of freedom to slide in the vertical direction with the help of vertical through grooves (19) arranged on the first slider (12) and the second slider (13). Compression springs (27) are respectively arranged between the lifting seat (18) and the first slider (12) and the second slider (13). The lifting seat (18) is also provided with a contoured insertion rod (20) inserted into the contoured guide rail (17). When the lifting seat (18) moves with the first slider (12) or the second slider (13), the rolling ball (5) is lifted or lowered along the contoured guide rail (17) with the help of the contoured insertion rod (20).

4. A high-precision PVC pipe automatic welding device according to claim 3, characterized in that: The profiling guide rail (17) is provided with a groove body with a horizontal D-shaped structure, the arched section of the groove body is higher than the straight section, the rolling ball (5) and the PVC welding sheet (3) are in rolling contact when the profiling rod (20) is located in the straight section, and the rolling ball (5) and the PVC welding sheet (3) are out of contact when the profiling rod (20) is located in the arched section. The groove body is provided with a swinging piece (21) at the intersection of the arched section and the straight section on the inner side of the weld, and the swinging piece (21) is oriented toward the inner side of the weld and droops by gravity to close the straight section.

5. The high-precision PVC pipe automatic welding device according to claim 1 is characterized in that: The driving ring (1) comprises a seat ring (101) and swing rings (102) hinged on both sides of the seat ring (101), a group of driving rollers are respectively arranged in the seat ring (101) and the swing ring (102), and the swing rings (102) on both sides are detachably connected by means of bolts.

6. A high-precision PVC pipe automatic welding device according to claim 5, characterized in that: The driving rollers are provided in groups of two, and include a wheel seat (22) for fixing to the side wall of a seat ring (101) or a swing ring (102), and swing arms (23) hinged to both sides of the wheel seat (22); a wheel body (24) driven by a driving motor is provided on the swing arms (23); and a tie spring (25) is provided between the swing arms (23).

7. A high-precision PVC pipe automatic welding device according to claim 6, characterized in that: A connecting rod (26) is provided between the wheel seats (22) of the driving roller wheels of the same group, and the connecting rod (26) is located between the hinge point of the swing arm (23) and the tie spring (25).

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