A rotational molding equipment and automatic conveying production line for plastic-impregnated steel pipes

Abstract

The present invention discloses a rotomolding device and an automatic conveying production line for a plastic-impregnated steel pipe, comprising a frame, on which a conveying roller is provided, on which a plurality of through holes for placing steel pipes are opened; and a spraying assembly, which comprises a fixed pipe fixedly mounted on the frame. The rotomolding device and the automatic conveying production line for a plastic-impregnated steel pipe provided by the invention, a first movable pipe drives the steel pipe to move, and sends the steel pipe to the fixed pipe, the spraying assembly in the fixed pipe sprays the steel pipe, the shaft drives the first movable pipe and the steel pipe to rotate, so that the spraying assembly can spray the coating more evenly on the outer wall of the steel pipe, the temperature of the steel pipe gradually decreases, when the temperature of the steel pipe decreases to a temperature suitable for powder attachment, the sealing plate on the shaft moves, the storage tank opens, the powder in the storage tank falls into the interior of the steel pipe, the powder is evenly attached to the inner wall of the steel pipe under the action of the centrifugal force of the steel pipe rotation, the conveying roller and the fixed pipe can slow down the heat dissipation of the steel pipe, and ensure the spraying effect.

Description

Technical Field

[0001] The present invention relates to the technical field of steel pipe processing, and in particular to rotational molding equipment and an automatic conveying production line for plastic-impregnated steel pipes. Background Art

[0002] Roto-molding is one of the commonly used methods for steel pipe processing. It combines steel pipes with plastics through sintering furnaces, roto-molding machines and other professional roto-molding equipment to form a new type of anti-corrosion pipeline.

[0003] According to the publication (announcement) number CN104368505B, the publication (announcement) date is 2016.12.07, and a steel pipe inner wall rotation molding machine is disclosed, comprising a base, a swinging table, an axial swinging mechanism, a rotating mechanism, a heating mechanism and an end gap sealing mechanism; the base comprises a base and a spindle seat; the spindle seat is arranged at the top of the base and is rotatably connected to the spindle; the axial swinging mechanism comprises a spindle, which is passed through the middle of the swinging table and is rotatably connected to the top of the base at both ends; the swinging table is rotatably connected to the base through the spindle; the rotating mechanism comprises a rotating motor, a second transmission belt, an active rotating shaft, a passive rotating shaft, a positioning wheel, a positioning ring and a rotating ring; the rotating motor is fixedly arranged on the swinging table; one side of the second transmission belt is connected to the output end of the rotating motor, and the other side is connected to the active rotating shaft; the active rotating shaft and the passive rotating shaft are arranged at intervals and are parallel to each other. The device can produce finished products with a diameter of up to several meters, and is suitable for processing products with different pipe diameters, with a wide range of applications; the finished products produced by the device have uniform wall thickness, less waste, and almost no internal stress, so they are not prone to deformation, dents and other defects; the device can adjust the swing angle, rotation speed, and heating temperature of the steel pipe, so as to more accurately control the production process of the steel-plastic composite pipe, with convenient and flexible operation and good quality of the finished product. At the same time, by changing the traditional manual layer-by-layer application, the working environment is improved and the processing efficiency is improved.

[0004] In the prior art including the above patents, when performing rotational molding of steel pipes, the steel pipes need to be heated first, then the outer wall of the steel pipes needs to be sprayed with coating, and the temperature of the steel pipes needs to be waited for to drop to a suitable range, and then powder materials need to be fed into the inside of the steel pipes, and the steel pipes need to be driven to rotate, and the powder materials inside the steel pipes need to be evenly attached to the inner wall of the steel pipes under the action of centrifugal force, and then the steel pipes need to be sent back to the heating furnace for baking. In the whole process, workers need to control the temperature very accurately, otherwise it is easy to affect the adhesion effect of the coating and powder materials on the steel pipe wall. Summary of the invention

[0005] The purpose of the present invention is to provide a rotational molding device and an automatic conveying production line for plastic-impregnated steel pipes, aiming to solve the problem that the temperature of the steel pipe is difficult to control during the rotational molding process of the steel pipe.

[0006] In order to achieve the above-mentioned object, the present invention provides a rotational molding device for a plastic-impregnated steel pipe, comprising a frame, on which are provided:

[0007] A conveying roller, on which a plurality of through holes for placing steel pipes are opened;

[0008] A spray assembly, which includes a fixed pipe fixedly mounted on a frame;

[0009] The pipe handling assembly comprises a shaft rod movably mounted on the frame and a first movable pipe sleeved on the shaft rod and used to fix the steel pipe, wherein:

[0010] The shaft is provided with a material storage trough for storing powder and a sealing plate for closing the material storage trough, and the sealing plate moves to control the opening or closing of the material storage trough.

[0011] Preferably, a cavity for accommodating the sealing plate is provided on the shaft rod, and an expansion body is arranged inside the cavity.

[0012] Preferably, a mounting plate is symmetrically arranged on the first movable tube, and a plurality of fixing rods are movably arranged on the mounting plate, and the plurality of fixing rods move to secure the steel tube.

[0013] Preferably, a second movable tube is provided between the shaft rod and the first movable tube, and a driving disk is symmetrically provided on the second movable tube, and the driving disk rotates to make the plurality of fixed rods move synchronously.

[0014] Preferably, a loading frame for pushing powder is movably provided on the second movable tube, and the second movable tube moves to make the loading frame move relative to the shaft rod.

[0015] Preferably, a third movable tube is provided between the second movable tube and the shaft rod, and the second movable tube moves so that the third movable tube is inserted into the frame.

[0016] Preferably, the fixing rod is provided with a pin rod extending into the interior of the third movable tube, and the frame is provided with a bearing for fixing the third movable tube.

[0017] Preferably, a nozzle is symmetrically and movably arranged inside the fixed pipe, and push rods are symmetrically arranged on the nozzle. The nozzle moves so that the push rods are tightly attached to the steel pipe.

[0018] Preferably, it further comprises a driving assembly, wherein the driving assembly comprises a first motor fixedly mounted on the frame and used for driving the second movable tube to rotate, and a telescopic rod used for driving the first movable tube to move relative to the shaft.

[0019] An automatic conveying production line comprises the rotational molding equipment for plastic-dipped steel pipes described in the above scheme.

[0020] In the above technical scheme, the present invention provides a rotational molding equipment and automatic conveying production line for plastic-impregnated steel pipes, which have the following beneficial effects: when the steel pipe is rotationally molded, the heated steel pipe is first sent to the through hole on the conveying roller, the conveying roller rotates, driving the steel pipe to rotate, so that the steel pipe and the fixed pipe of the spraying assembly are coaxially distributed, at this time the pipeline handling assembly moves, the first movable pipe is inserted into the steel pipe, and the steel pipe is fixed, the first movable pipe drives the steel pipe to move, and the steel pipe is sent to the fixed pipe, and the spraying assembly in the fixed pipe performs rotational molding on the steel pipe. During spraying, the shaft drives the first movable tube and the steel tube to rotate, so that the spraying assembly can spray the paint more evenly on the outer wall of the steel tube, and the temperature of the steel tube gradually decreases. When the temperature of the steel tube drops to a temperature suitable for powder adhesion, the sealing plate on the shaft moves, the storage tank opens, and the powder in the storage tank falls into the inside of the steel tube. Under the action of the centrifugal force of the rotation of the steel tube, the powder is evenly attached to the inner wall of the steel tube. The conveying roller and the fixed tube can slow down the heat dissipation of the steel tube, ensuring that the steel tube is sprayed at a higher temperature to ensure the spraying effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0022] Figure 1 A schematic diagram of the overall structure provided for an embodiment of the present invention;

[0023] Figure 2 A schematic diagram of the structure of a drive assembly provided by an embodiment of the present invention;

[0024] Figure 3 for Figure 2 Enlarged view of point A in the middle;

[0025] Figure 4 A schematic diagram of the structure of a pipeline handling assembly provided in an embodiment of the present invention;

[0026] Figure 5 for Figure 4 Enlarged view of point B in the middle;

[0027] Figure 6 A schematic diagram of the internal structure provided by an embodiment of the present invention;

[0028] Figure 7 for Figure 6 Enlarged view of point C in the middle;

[0029] Figure 8 for Figure 6 Enlarged view of point D in the middle;

[0030] Fig. 9 A schematic diagram of the structure of a shaft provided by an embodiment of the present invention;

[0031] Fig.10 for Fig. 9 Enlarged view of point E in the middle;

[0032] Fig.11 A schematic diagram of the cross-sectional structure of a shaft rod provided in an embodiment of the present invention.

[0033] Description of reference numerals:

[0034] 1. Frame; 11. Pipe handling assembly; 111. First movable pipe; 112. Second movable pipe; 113. Third movable pipe; 114. Movable plate; 115. Shaft; 116. Storage tank; 117. Closing plate; 12. Spraying assembly; 121. Fixed pipe; 122. Movable rod; 123. Tenon; 124. Guide groove; 125. Spray head; 126. Delivery pipe; 127. Push rod; 13. Driving assembly; 131. First A motor; 132, a first gear; 133, a first gear ring; 134, a telescopic rod; 135, a connecting rod; 136, a second gear; 137, a third gear; 138, a second gear ring; 139, an impeller; 14, a conveying roller; 141, a mounting plate; 142, a fixing rod; 143, a driving plate; 144, a pin rod; 145, a bearing; 146, an elastic sheet; 147, a feeding frame; 148, a pulling rod; 149, a feeding trough. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0036] like Figure 1-11 As shown, a rotational molding device and an automatic conveying production line for a plastic-impregnated steel pipe include a frame 1, on which are provided:

[0037] The conveying roller 14 is provided with a plurality of through holes for placing the steel pipes;

[0038] A spray assembly 12, comprising a fixed pipe 121 fixedly mounted on the frame 1;

[0039] The pipe handling assembly 11 comprises a shaft 115 movably mounted on the frame 1 and a first movable pipe 111 sleeved on the shaft 115 and used to fix the steel pipe, wherein:

[0040] A material storage trough 116 for storing powder and a sealing plate 117 for closing the material storage trough 116 are provided on the shaft 115 . The sealing plate 117 moves to control the material storage trough 116 to be opened or closed.

[0041] Specifically, when performing rotational molding of a steel pipe, it is necessary to first heat the steel pipe, then spray a coating on the outer wall of the steel pipe, wait for the temperature of the steel pipe to drop to a suitable range, feed powder into the inside of the steel pipe, drive the steel pipe to rotate, and the powder inside the steel pipe is evenly attached to the inner wall of the steel pipe under the action of centrifugal force. Then the steel pipe is sent back to the heating furnace to cure the coating on the steel pipe. This is a prior art and will not be described in detail.

[0042] Furthermore, the conveying roller 14 is rotatably mounted on the frame 1, and is provided with a motor for driving the conveying roller 14 to rotate, a nozzle 125 is provided inside the fixed tube 121, and a notch for powder to pass through is provided on the first movable tube 111; when the steel tube is rotationally molded, the heated steel tube is first sent to the through hole on the conveying roller 14, the motor drives the conveying roller 14 to rotate, and the conveying roller 14 drives the steel tube to move, so that the steel tube and the fixed tube 121 of the spraying assembly 12 are coaxially distributed, at this time the pipeline handling assembly 11 moves, the first movable tube 111 is inserted into the steel tube, and the steel tube is fixed, the first movable tube 111 drives the steel tube to move, and the steel tube is sent to the fixed tube 121. In the tube 121, the nozzle 125 in the fixed tube 121 sprays the steel tube, and the shaft 115 drives the first movable tube 111 and the steel tube to rotate, so that the nozzle 125 can spray the paint more evenly on the outer wall of the steel tube, and the temperature of the steel tube gradually decreases. When the temperature of the steel tube drops to a temperature suitable for the adhesion of powder, the sealing plate 117 on the shaft 115 moves, and the storage tank 116 opens. The powder in the storage tank 116 falls into the inside of the steel tube, and the powder is evenly attached to the inner wall of the steel tube under the action of the centrifugal force of the rotation of the steel tube. The conveying roller 14 and the fixed tube 121 can slow down the heat dissipation of the steel tube, ensure that the steel tube is sprayed at a higher temperature, and ensure the spraying effect.

[0043] Furthermore, in the above embodiment, an electric telescopic rod 134 may be arranged inside the shaft 115, and a sealing plate 117 may be arranged on the output end of the electric telescopic rod 134. A temperature control switch for controlling the electric telescopic rod 134 may be arranged inside the shaft 115. When the temperature of the steel pipe is higher than the temperature suitable for the adhesion of the powder, the electric telescopic rod 134 pushes the sealing plate 117 to close the storage tank 116 on the shaft 115, and the powder remains in the shaft 115. When the temperature of the steel pipe is reduced to a temperature suitable for the adhesion of the powder, the temperature control switch controls the electric telescopic rod 134 to work, and the electric telescopic rod 134 drives the sealing plate 117 to move to open the storage tank 116. During the rotation of the shaft 115, the powder in the storage tank 116 passes through the notch on the first movable tube 111 and falls into the interior of the steel pipe, and the powder is evenly attached to the inner wall of the steel pipe under the action of the centrifugal force when the steel pipe rotates. Other structures that can be obtained by those skilled in the art based on common technical knowledge are also possible.

[0044] In the above technical solution, when the steel pipe is subjected to rotational molding, the heated steel pipe is first sent to the through hole on the conveying roller 14, and the conveying roller 14 rotates to drive the steel pipe to rotate, so that the steel pipe and the fixed pipe 121 of the spraying assembly 12 are coaxially distributed. At this time, the pipeline handling assembly 11 moves, and the first movable pipe 111 is inserted into the steel pipe and fixed. The first movable pipe 111 drives the steel pipe to move and sends the steel pipe to the fixed pipe 121. The spraying assembly 12 in the fixed pipe 121 sprays the steel pipe, and the shaft 115 drives the first movable pipe 11 1 and the steel pipe rotate, so that the spraying assembly 12 can spray the paint more evenly on the outer wall of the steel pipe, and the temperature of the steel pipe gradually decreases. When the temperature of the steel pipe drops to a temperature suitable for the adhesion of powder, the sealing plate 117 on the shaft 115 moves, the storage tank 116 opens, and the powder in the storage tank 116 falls into the inside of the steel pipe. The powder is evenly attached to the inner wall of the steel pipe under the action of the centrifugal force of the rotation of the steel pipe. The conveying roller 14 and the fixed pipe 121 can slow down the heat dissipation of the steel pipe, ensure that the steel pipe is sprayed at a higher temperature, and ensure the spraying effect.

[0045] As a further embodiment of the present invention, a cavity for accommodating the sealing plate 117 is opened on the shaft rod 115, and an expansion body is arranged inside the cavity.

[0046] Specifically, a spring is provided between the sealing plate 117 and the shaft rod 115, and the expansion body is specifically a gas with a high thermal expansion coefficient (such as hydrogen, helium, nitrogen).

[0047] Furthermore, when the temperature of the steel pipe is higher than the temperature suitable for powder adhesion, the expansion body in the cavity expands and pushes the sealing plate 117 to close the storage tank 116 on the shaft 115, and the powder remains in the shaft 115. When the temperature of the steel pipe drops to a temperature suitable for powder adhesion, the expansion body contracts, and the spring between the sealing plate 117 and the shaft 115 pulls the sealing plate 117 to open the storage tank 116. During the rotation of the shaft 115, the powder in the storage tank 116 passes through the notch on the first movable tube 111 and falls into the interior of the steel pipe. Under the action of the centrifugal force when the steel pipe rotates, the powder is evenly attached to the inner wall of the steel pipe.

[0048] As another embodiment further provided by the present invention, a mounting plate 141 is symmetrically arranged on the first movable tube 111 , and a plurality of fixing rods 142 are movably arranged on the mounting plate 141 , and the plurality of fixing rods 142 move to secure the steel tube.

[0049] Specifically, when moving the steel pipe, the first movable tube 111 is driven to move, the first movable tube 111 is inserted into the steel pipe, and the two mounting plates 141 on the first movable tube 111 enter the steel pipe and are located at both ends of the steel pipe. At this time, the fixing rod 142 is driven to move, and the fixing rod 142 rests on the inner wall of the steel pipe to fix the steel pipe on the first movable tube 111. Then the first movable tube 111 brings the steel pipe into the fixed tube 121 for spraying.

[0050] As another embodiment further provided by the present invention, a second movable tube 112 is disposed between the shaft 115 and the first movable tube 111 , and a driving disk 143 is symmetrically disposed on the second movable tube 112 , and the driving disk 143 rotates to make the multiple fixed rods 142 move synchronously.

[0051] Specifically, the driving disc 143 is provided with a planar thread, and the fixing rod 142 is provided with a sliding groove adapted to the planar thread.

[0052] Furthermore, when the steel pipe is moved, the second movable tube 112 is driven to move, and the second movable tube 112 pushes the first movable tube 111 through the driving disk 143. The first movable tube 111 is inserted into the steel pipe, and the two mounting disks 141 on the first movable tube 111 enter the steel pipe and are located at both ends of the steel pipe. At this time, the second movable tube 112 is driven to drive the driving disk 143 to rotate, and the flat thread on the driving disk 143 moves along the sliding groove on the fixed rod 142, and then pushes the fixed rod 142, so that the end of the fixed rod 142 is against the inner wall of the steel pipe, and the steel pipe is fixed on the first movable tube 111. Then the second movable tube 112 brings the steel pipe to the fixed tube 121 for spraying.

[0053] As another embodiment further provided by the present invention, a loading frame 147 for pushing powder is movably provided on the second movable tube 112 , and the second movable tube 112 moves to enable the loading frame 147 to move relative to the shaft 115 .

[0054] Specifically, a feeding trough 149 is provided on the frame 1, and the bottom of the feeding trough 149 is opposite to the feeding frame 147. A telescopic plate is provided at the bottom of the feeding trough 149. A pulling rod 148 is movably provided on the second movable tube 112, and a magnet is provided at the end of the pulling rod 148. A magnet is also provided on the feeding frame 147.

[0055] Furthermore, when the second movable tube 112 approaches the conveying roller 14, the magnet on the pulling rod 148 on the second movable tube 112 is attracted to the magnet on the loading frame 147, driving the loading frame 147 to move, and the loading frame 147 pulls the telescopic plate to seal the bottom of the loading trough 149 to prevent the powder from falling. The loading frame 147 moves along the shaft 115 with the powder, and the powder in the loading frame 147 gradually falls into the storage trough 116 on the shaft 115. The pulling rod 148 can be separated from the loading frame 147 and will not affect the rotation of the second movable tube 112. When the second movable tube 112 moves the steel pipe to the fixed tube 121, the loading frame 147 returns to the bottom of the loading trough 149 and pushes the telescopic plate to open the loading trough 149 for material dropping.

[0056] As another embodiment further provided by the present invention, a third movable tube 113 is disposed between the second movable tube 112 and the shaft rod 115 , and the second movable tube 112 moves so that the third movable tube 113 is inserted into the frame 1 .

[0057] Specifically, when the second movable tube 112 approaches the conveying roller 14, the third movable tube 113 also approaches the conveying roller 14, and the end of the third movable tube 113 is gradually inserted into the frame 1. Then the second movable tube 112 approaches the fixed tube 121 with the steel pipe, and the end of the third movable tube 113 is inserted into the frame 1, and the other end contacts with the shaft rod 115 and the second movable tube 112, supporting the shaft rod 115 and the second movable tube 112 to prevent the shaft rod 115 and the second movable tube 112 from being bent by the steel pipe.

[0058] As another embodiment further provided by the present invention, a pin rod 144 extending into the third movable tube 113 is disposed on the fixing rod 142 , and a bearing 145 for fixing the third movable tube 113 is disposed on the frame 1 .

[0059] Specifically, a plurality of elastic sheets 146 for fixing the third movable tube 113 are provided on the inner ring of the bearing 145 , a through hole adapted to the elastic sheets 146 is provided on the third movable tube 113 , and a through hole adapted to the contraction pin 144 is provided on the third movable tube 113 .

[0060] Further, when the second movable tube 112 approaches the conveying roller 14, the pin rod 144 on the fixed tube 121 pushes the third movable tube 113 toward the conveying roller 14, and the end of the third movable tube 113 is gradually inserted into the bearing 145 on the frame 1, and the elastic sheet 146 on the bearing 145 is inserted into the third movable tube 113. The second movable tube 112 rotates to push the fixed rod 142 to move, and the fixed rod 142 abuts against the inner wall of the steel pipe. The pin rod 144 on the fixed rod 142 is separated from the third movable tube 113, and then the second movable tube 112 brings the steel pipe toward the fixed tube 121, and the end of the third movable tube 113 is inserted into the frame 1, and the other end contacts with the shaft rod 115 and the second movable tube 112, supporting the shaft rod 115 and the second movable tube 112 to prevent the shaft rod 115 and the second movable tube 112 from being bent by the steel pipe.

[0061] As another embodiment further provided by the present invention, a nozzle 125 is symmetrically and movably arranged inside the fixed pipe 121, and a push rod 127 is symmetrically arranged on the nozzle 125. The nozzle 125 moves to make the push rod 127 close to the steel pipe.

[0062] Specifically, it also includes a movable disk 114 rotatably installed on a fixed tube 121, a shaft 115 is provided on the movable disk 114, a movable rod 122 is movably provided inside the fixed tube 121, a nozzle 125 is movably provided on the movable rod 122, a spring is provided between the nozzle 125 and the movable rod 122, a tenon 123 extending to the inside of the movable disk 114 is provided on the movable rod 122, a guide groove 124 for guiding the movement of the tenon 123 is provided on the movable disk 114, the guide groove 124 includes an inclined portion and an annular groove portion, and a delivery pipe 126 connected to the delivery pump is provided on the nozzle 125.

[0063] Furthermore, when spraying, the movable disk 114 rotates to drive the steel pipe to rotate, and the guide groove 124 on the movable disk 114 pushes the tenon 123 on the movable rod 122. The tenon 123 moves along the inclined portion of the guide groove 124, and then drives the movable rod 122 to approach the steel pipe. The movable rod 122 pushes the nozzle 125 through the spring until the push rod 127 on the nozzle 125 abuts against the outer wall of the steel pipe. At this time, the distance between the nozzle 125 and the steel pipe is fixed, and the movable rod 122 continues to move, compressing the spring between it and the nozzle 125, and the tenon 123 enters the annular groove portion of the guide groove 124. The movable disk 114 can rotate freely, driving the steel pipe to rotate, and the delivery pump works to deliver the paint to the nozzle 125 through the delivery pipe 126, and the nozzle 125 is used to spray the outer wall of the steel pipe.

[0064] As another embodiment further provided by the present invention, it also includes a driving assembly 13, which includes a first motor 131 fixedly mounted on the frame 1 and used to drive the second movable tube 112 to rotate, and a telescopic rod 134 used to drive the first movable tube 111 to move relative to the shaft 115.

[0065] Specifically, a first gear 132 is provided on the output end of the first motor 131, a first gear ring 133 meshing with the first gear 132 is provided inside the frame 1, a telescopic rod 134 is symmetrically provided on the gear ring, a connecting rod 135 passing through the movable disk 114 is provided on the second movable tube 112, the connecting rod 135 is fixedly installed on the output end of the telescopic rod 134, an arc-shaped notch for the connecting rod 135 to pass through is provided on the movable disk 114, a notch for the feeding frame 147 to pass through is provided on the movable disk 114, a rotation damping is provided between the movable disk 114 and the fixed tube 121, a telescopic plate is provided between the movable disk 114 and the first movable tube 111, and specifically, the telescopic rod 134 is an electric telescopic rod 134.

[0066] Furthermore, an impeller 139 is rotatably provided on the movable disk 114 , a second gear ring 138 is provided on the impeller 139 , and a coaxially distributed second gear 136 and a third gear 137 are rotatably provided inside the frame 1 , the second gear 136 is meshed with the first gear 132 , and the third gear 137 is meshed with the second gear ring 138 .

[0067] Furthermore, when the steel pipe is subjected to rotational molding, the heated steel pipe is first sent to the through hole on the conveying roller 14, and the motor drives the conveying roller 14 to rotate, and the conveying roller 14 drives the steel pipe to move, so that the steel pipe is coaxially distributed with the fixed pipe 121 of the spraying assembly 12;

[0068] The telescopic rod 134 extends to push the second movable tube 112 toward the steel tube. The second movable tube 112 drives the third movable tube 113 toward the conveying roller 14 through the pin rod 144. The end of the third movable tube 113 is gradually inserted into the bearing 145 on the frame 1. The elastic sheet 146 on the bearing 145 is inserted into the third movable tube 113. The second movable tube 112 pushes the first movable tube 111 through the driving disk 143. The first movable tube 111 is inserted into the steel tube. The two mounting disks 141 on the first movable tube 111 enter the steel tube and are located on both sides of the steel tube. At the end, the first motor 131 works to drive the first gear 132 to rotate. The first gear 132 drives the connecting rod 135 and the second movable tube 112 to rotate through the first gear ring 133 meshing therewith. The second movable tube 112 drives the driving disk 143 to rotate. The flat thread on the driving disk 143 moves along the slide groove on the fixing rod 142, and then pushes the fixing rod 142, so that the end of the fixing rod 142 abuts against the inner wall of the steel pipe, fixes the steel pipe on the first movable tube 111, and the pin rod 144 on the fixing rod 142 is separated from the third movable tube 113.

[0069] When the second movable tube 112 moves, the magnet on the pulling rod 148 on the second movable tube 112 attracts the magnet on the loading frame 147, driving the loading frame 147 to move, and the loading frame 147 pulls the telescopic plate, and the bottom of the loading trough 149 is sealed to prevent the powder from falling. The loading frame 147 moves along the shaft 115 with the powder, and the powder in the loading frame 147 gradually falls into the storage trough 116 on the shaft 115. The pulling rod 148 can be separated from the loading frame 147 without affecting the rotation of the second movable tube 112;

[0070] Then the telescopic rod 134 is shortened, and the second movable tube 112 brings the steel tube into the fixed tube 121. The end of the third movable tube 113 is inserted into the frame 1, and the other end contacts the shaft rod 115 and the second movable tube 112, supporting the shaft rod 115 and the second movable tube 112 to prevent the shaft rod 115 and the second movable tube 112 from being bent by the steel tube. The feeding frame 147 returns to the bottom of the feeding trough 149 and pushes the telescopic plate to open the feeding trough 149 for feeding. At this time, the temperature of the steel tube is higher than the temperature suitable for the powder to adhere, the expansion body in the cavity expands, and pushes the sealing plate 117 to close the storage trough 116 on the shaft rod 115, and the powder remains in the shaft rod 115.

[0071] The first motor 131 continues to work, pushing the second movable tube 112 to rotate. The second movable tube 112 drives the first movable tube 111 to rotate through the driving disk 143 and the fixed rod 142, and then drives the movable disk 114 to rotate to overcome the resistance of the rotation damping. The guide groove 124 on the movable disk 114 pushes the tenon block 123 on the movable rod 122. The tenon block 123 moves along the inclined portion of the guide groove 124, and then drives the movable rod 122 steel pipe to approach. The movable rod 122 pushes the nozzle 125 through the spring until Until the push rod 127 on the nozzle 125 abuts against the outer wall of the steel pipe, the distance between the nozzle 125 and the steel pipe is fixed, the movable rod 122 continues to move, compressing the spring between it and the nozzle 125, the tenon 123 enters the annular groove of the guide groove 124, the movable disk 114 can rotate freely, driving the steel pipe to rotate, the delivery pump works, and the paint is delivered to the nozzle 125 through the delivery pipe 126, and the nozzle 125 is used to spray the outer wall of the steel pipe, and the paint is evenly sprayed on the outer wall of the steel pipe;

[0072] While the spraying work is being performed, the first gear 132 on the first motor 131 drives the second gear 136 meshing therewith to rotate, and the second gear 136 drives the second gear ring 138 to rotate through the third gear 137, and then drives the impeller 139 to rotate, thereby accelerating the air flow inside the steel pipe and shortening the cooling time of the steel pipe;

[0073] When the temperature of the steel pipe is lowered to a temperature suitable for powder to adhere to, the expansion body contracts, and the spring between the sealing plate 117 and the shaft 115 pulls the sealing plate 117 to open the storage tank 116. During the rotation of the shaft 115, the powder in the storage tank 116 passes through the notches on the first movable tube 111 and the second movable tube 112 and falls into the steel pipe. The powder is evenly attached to the inner wall of the steel pipe under the action of the centrifugal force when the steel pipe rotates.

[0074] Then the telescopic rod 134 is extended to send the steel pipe with paint attached back to the conveying roller 14, the first motor 131 is reversed, driving the second movable tube 112 to reverse, the driving disk 143 drives the fixed rod 142 to retract into the mounting disk 141, and the pin 144 on the fixed rod 142 is inserted back into the third fixed tube 121, then the telescopic rod 134 is shortened, and the second movable tube 112 drives the first movable tube 111 and the third movable tube 113 to move and retract into the fixed tube 121 for subsequent work, and the conveying roller 14 sends the steel pipe with paint attached back to the heating furnace to solidify the paint on the steel pipe.

[0075] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A rotational molding device for plastic-impregnated steel pipes, characterized in that: The machine comprises a frame (1), on which is arranged: A conveying roller (14) having a plurality of through holes for placing steel pipes; A spraying assembly (12), comprising a fixed pipe (121) fixedly mounted on the frame (1); A pipe handling assembly (11) comprises a shaft (115) movably mounted on the frame (1) and a first movable pipe (111) sleeved on the shaft (115) and used to fix the steel pipe, wherein: The shaft (115) is provided with a material storage trough (116) for storing powder and a sealing plate (117) for sealing the material storage trough (116), wherein the sealing plate (117) moves to control the opening or closing of the material storage trough (116); A mounting plate (141) is symmetrically arranged on the first movable tube (111), and a plurality of fixing rods (142) are movably arranged on the mounting plate (141), and the plurality of fixing rods (142) move to secure the steel tube; A second movable tube (112) is arranged between the shaft rod (115) and the first movable tube (111), and a driving disk (143) is symmetrically arranged on the second movable tube (112), and the driving disk (143) rotates to make the plurality of fixed rods (142) move synchronously; A loading frame (147) for pushing powder is movably provided on the second movable tube (112), and the second movable tube (112) moves to enable the loading frame (147) to move relative to the shaft (115); A third movable tube (113) is provided between the second movable tube (112) and the shaft rod (115), and the second movable tube (112) moves so that the third movable tube (113) is inserted into the frame (1); The fixing rod (142) is provided with a pin rod (144) extending into the interior of the third movable tube (113), and the frame (1) is provided with a bearing (145) for fixing the third movable tube (113); The shaft rod (115) is provided with a cavity for accommodating the sealing plate (117), and an expansion body is arranged inside the cavity; A nozzle (125) is symmetrically and movably arranged inside the fixed pipe (121), and a push rod (127) is symmetrically arranged on the nozzle (125). The nozzle (125) moves so that the push rod (127) is in close contact with the steel pipe.

2. A rotational molding device for plastic-impregnated steel pipes according to claim 1, characterized in that: It also comprises a driving assembly (13), the driving assembly (13) comprising a first motor (131) fixedly mounted on the frame (1) and used to drive the second movable tube (112) to rotate, and a telescopic rod (134) used to drive the first movable tube (111) to move relative to the shaft (115).

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