A shading system and its application

Abstract

The present invention proposes a shielding system and its application, which belongs to the technical field of anti-corrosion pipe production equipment. It includes a pipe unit located on the production line, a powder spraying chamber frame, a first mounting plate, a lifting mechanism and a shielding mechanism. The pipe unit passes through the powder spraying chamber frame, and a powder spraying chamber is formed in the powder spraying chamber frame. The first mounting plate is connected to the lifting mechanism and can be lifted and lowered in the vertical direction under the drive of the lifting mechanism. A shielding mechanism is provided on the first mounting plate. The shielding mechanism can shield a predetermined area of the pipe unit and follow the pipe unit to move synchronously along its axial direction to pass through the powder spraying chamber while shielding, thereby preventing powder from the powder spraying chamber from being sprayed to the predetermined area. The shielding system of the present invention effectively solves the problems of complex production process, material waste and large amount of waste generated in the current 3PE anti-corrosion pipe production.

Description

Technical Field

[0001] The present invention belongs to the technical field of anti-corrosion pipe production equipment, and in particular relates to a shielding system and application thereof. Background Art

[0002] Anti-corrosion pipe (also known as anti-corrosion steel pipe) is a steel pipe treated with a special anti-corrosion process. Common anti-corrosion pipes include FBE pipe (single-layer fusion-bonded epoxy powder), 3PE pipe (epoxy powder layer + copolymer adhesive layer + polyethylene layer), coal tar enamel pipe, and polyurethane foam insulation pipe. FBE and 3PE pipes, both of which incorporate epoxy powder in their anti-corrosion coatings, offer significantly better adhesion and corrosion resistance than traditional anti-corrosion pipes, leading to their widespread use.

[0003] During the production of FBE and 3PE anti-corrosion pipes, it is generally required to leave a sufficient uncoated area at the pipe ends (for example, a 10 to 15 cm uncoated area along the pipe axis). This is because during on-site construction, these anti-corrosion pipes are often connected by welding (especially in the oil and gas transportation industry). If the pipe ends are coated with epoxy powder coating, the welding quality will be seriously affected. This influence mainly comes from: 1. The high temperature generated during the welding process will cause the anti-corrosion layer material to decompose, carbonize and other changes, producing gases and impurities. These gases and impurities will be mixed into the weld, forming welding defects such as pores and inclusions, seriously affecting the quality and strength of the weld, and reducing the mechanical properties of the welded joint; 2. In order to prevent media such as oil and natural gas from leaking from the pipeline connection during transportation, welding is required to form continuous, dense and defect-free welds; if the anti-corrosion layer is not removed cleanly, it will hinder the close fit between the weld and the steel pipe substrate, resulting in gaps or weak links between the weld and the substrate; 3. When welding directly without removing the anti-corrosion layer, the heat generated during the welding process will cause the edge of the anti-corrosion layer to be heated unevenly, resulting in a decrease in the bonding strength between the edge of the anti-corrosion layer and the base metal, resulting in warping or falling off, etc.

[0004] To preserve sufficient uncoated area at the pipe ends, a technical solution has been proposed, using a masking material such as kraft paper to prevent the pipe ends from being coated with epoxy powder coating. However, this method involves complex production processes (adding the steps of applying and subsequently removing the kraft paper, which increases labor costs), significant paint waste (the epoxy powder fuses to the kraft paper, making it unreusable), and significant waste generation (after the kraft paper is removed, the kraft paper and the epoxy powder solidified on it must be discarded, generating significant waste and causing environmental pollution). This has prompted efforts to improve existing technologies. Currently, for the production of FBE-coated steel pipes, we have developed a pipe end connector and system incorporating it, for which we have applied for a Chinese invention patent (application number CN202410749640.6). This pipe end connector effectively addresses the problem of anti-corrosion coating on the pipe ends of conventional epoxy powder (FBE)-coated steel pipes. However, the aforementioned pipe end connectors are not suitable for 3PE anti-corrosion steel pipes for the following reasons: 1. During the production process, the epoxy powder layer, copolymer adhesive layer, and polyethylene layer must be continuously completed on the same production line. If these pipe end connectors are used, since they allow the two connected pipes to rotate and expand and contract in the axial direction during use, this will seriously affect the winding and bonding quality of the copolymer adhesive layer and the polyethylene layer. For example, this may lead to uneven thickness of the anti-corrosion layer, decreased interlayer bonding strength, and substandard bonding strength between the layers (especially near the pipe ends), ultimately affecting product quality. 2. These pipe end connectors require a certain slope at the end of the connected pipe. For pipes without a slope, the outer diameter of the pipe end connector will differ significantly from the outer diameter of the connected pipe, further affecting the subsequent winding and bonding quality of the copolymer adhesive layer and the polyethylene layer. Given these issues, the current solution for 3PE anti-corrosion steel pipes is to apply a shielding material such as kraft paper to the pipe ends.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the present invention proposes a shielding system and its application, aiming to overcome at least one of the above-mentioned defects.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0008] A shielding system includes a pipe unit, a powder spraying chamber frame, a first mounting plate, a lifting mechanism and a shielding mechanism located on a production line, wherein the pipe unit passes through the powder spraying chamber frame, a powder spraying chamber is formed in the powder spraying chamber frame, the first mounting plate is connected to the lifting mechanism and can be lifted and lowered in a vertical direction under the drive of the lifting mechanism, and a shielding mechanism is provided on the first mounting plate, the shielding mechanism can shield a predetermined area of the pipe unit, and while shielding, follow the pipe unit to move synchronously along its axial direction to pass through the powder spraying chamber, thereby preventing powder from the powder spraying chamber from being sprayed to the predetermined area.

[0009] Preferably, the powder spraying chamber frame includes a left frame and a right frame, and there is a gap between the left frame and the right frame. At the gap position, the left frame and the right frame are connected by a transition part, and the production channel runs through the left frame, the right frame and the transition part. A first cavity and a second cavity are formed in the left frame and the right frame respectively, and a powder spraying cavity is formed in the transition part. The first cavity, the powder spraying cavity and the second cavity together constitute the powder spraying chamber, and the nozzle for spraying epoxy powder is arranged in the powder spraying cavity.

[0010] Preferably, the shielding mechanism includes a second mounting plate, a shielding assembly and a synchronous rolling mechanism, the second mounting plate is slidably arranged below the first mounting plate, the shielding assembly and the synchronous rolling mechanism are fixedly arranged below the second mounting plate, and the synchronous rolling mechanism includes a third power unit, an arm unit and a roller, wherein the rotation axis of the roller is parallel to the axis of the pipe unit, the output end of the third power unit is connected to one end of the arm unit, and the other end of the arm unit is connected to the roller, and the third power unit can drive the arm unit to move so that the roller is pressed against the surface of the pipe unit.

[0011] Further preferably, the synchronous rolling mechanism also includes a support plate unit, a first hinge unit and a second hinge unit. The support plate unit is a "ㄇ"-shaped structure, which includes a horizontal plate located at the top and side plates located on both sides of the horizontal plate. The synchronous rolling mechanism is fixedly connected to the second mounting plate through the horizontal plate. The third power unit and the arm unit are rotatably arranged between the two side plates. The output end of the third power unit is hinged to one end of the arm unit through the second hinge unit. The middle part of the arm unit is hinged to the two side plates through the first hinge unit. The roller is set at the end of the arm unit away from the second hinge unit.

[0012] Further preferably, the bottom of the first mounting plate is also provided with an initial position and an end position for limiting the movement of the shielding mechanism, and a first sensor and a second sensor are respectively provided at the initial position and the end position, and the fourth power unit is operated according to the signals of the first sensor and the second sensor; when the first sensor detects that the shielding mechanism has reached the initial position, the fourth power unit stops operating, and when the second sensor detects that the shielding mechanism has reached the end position, the fourth power unit is started to work, so that the shielding mechanism moves toward the initial position and returns to the initial position; a third sensor is also provided at the initial position, and the third sensor is used to identify the connector, and the third power unit can be operated according to the signals of the second sensor and the third sensor; when the third sensor detects and identifies the connector, the third power unit is started to press the roller of the synchronous rolling mechanism against the surface of the pipe unit, thereby realizing the synchronous movement of the shielding mechanism following the pipe unit along its axial direction; when the second sensor detects that the shielding mechanism has reached the end position, the third power unit stops working, and the roller of the synchronous rolling mechanism is disengaged from the surface of the pipe unit.

[0013] It should be understood that the shielding system of the present invention is preferably applied to the production of 3PE anti-corrosion pipes.

[0014] Compared with the prior art, the present invention has at least the following beneficial effects:

[0015] The present invention proposes a shielding system, which is particularly suitable for the production of 3PE anti-corrosion pipes. By forming a shielding area outside the pipe unit, the tedious process of traditionally pasting kraft paper, tape and other shielding materials is eliminated, the production process is simplified, and the production efficiency is effectively improved; the shielding mechanism of the present invention is pressed against the pipe unit by the roller of its synchronous rolling mechanism, and the shielding mechanism is driven to move synchronously with the pipe unit through the movement of the pipe unit itself, without the need for complicated manual intervention, making the entire production process smoother and more coherent, easy to automatically control and integrate, and providing strong support for large-scale industrial production; compared with the existing technology, the shielding system of the present invention reduces the use of paint, reduces the cost of raw materials, and at the same time reduces the generation of waste, reduces the cost of waste treatment, and is more environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0017] Figure 1 is a schematic diagram of the three-dimensional structure of the shielding system of the present invention (partial structure is not shown);

[0018] Figure 2 It is a schematic diagram of the structure of connecting pipes on the production line;

[0019] Figure 3 yes Figure 1 The main structural diagram of the shading system shown;

[0020] Figure 4 yes Figure 1 A side structural diagram of the shielding system shown;

[0021] Figure 5 yes Figure 4 A partial enlarged view of area A in the middle;

[0022] Figure 6 1 is a schematic diagram of a partial three-dimensional structure of the synchronous rolling mechanism used in the present invention (part of the support plate is removed);

[0023] Figure 7 This is a schematic diagram of the three-dimensional structure of the shielding system of the present invention after removing the powder spraying chamber frame and other structures;

[0024] Figure 8 yes Figure 7 A schematic diagram of the upward structure of the shading system shown;

[0025] Figure 9 yes Figure 8 A partial enlarged view of the middle B area;

[0026] The meanings of the reference numerals are as follows:

[0027] 1-powder spray chamber frame, 2-first mounting plate, 3-lifting mechanism, 4-shielding mechanism, 5-lifting rod, 6-first power unit, 7-second mounting plate, 8-synchronous rolling mechanism, 9-baffle, 10-rack, 11-first slide rail unit, 12-second slide rail unit, 13-second power unit, 14-third power unit, 15-gear, 16-fourth power unit, 17-support plate unit, 18-first hinge unit, 19-arm unit, 20-roller, 21-second hinge unit, 22-first beam, 23-second beam, 24-suspension mechanism, 25-support rod, 26-guide block, 27-lifting column, 28-auxiliary unit,

[0028] 100 - first pipe, 101 - observation window, 102 - production channel, 103 - transition section, 104 - interval, 200 - second pipe, 300 - connector, 400 - shielding area. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with examples and drawings. The exemplary embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0030] Specifically, such as Figures 1 to 9 As shown, the present invention provides a shielding system, which includes a pipe unit located on a production line, a powder spraying chamber frame 1, a first mounting plate 2, a lifting mechanism 3 and a shielding mechanism 4, wherein the pipe unit passes through the powder spraying chamber frame 1, a powder spraying chamber is formed in the powder spraying chamber frame 1, the first mounting plate 2 is connected to the lifting mechanism 3 and can be driven by the lifting mechanism 3 along the vertical direction ( Figure 1 The first mounting plate 2 is provided with a shielding mechanism 4, which can shield a predetermined area of the pipe unit and follow the pipe unit along its axis direction ( Figure 1 The device moves synchronously (in the ox direction) to pass through the powder spraying room, thereby preventing the powder from the powder spraying room from being sprayed to the predetermined area.

[0031] It should be noted that in the prior art, in the process of producing anti-corrosion pipes by epoxy powder spraying, in order to prevent the epoxy powder from being sprayed onto the predetermined area, the common practice is to stick kraft paper, tape and other shielding materials on the predetermined area. This practice not only has the problem of complex production process, but also leads to serious waste of paint and generates a large amount of waste. The present invention forms a shield on the predetermined area of the pipe unit through the shielding mechanism 4. While shielding, the shielding mechanism 4 can follow the pipe unit and move synchronously along the axial direction of the pipe unit to pass through the powder spraying room. In this way, in the process of passing through the powder spraying room, the shielding mechanism 4 always blocks the predetermined area of the pipe unit, thereby preventing the epoxy powder from the powder spraying room from being sprayed onto the predetermined area. See Figure 2 In the process of using epoxy powder to spray the pipe unit to form an anti-corrosion pipe (such as 3PE anti-corrosion pipe), the pipe unit needs to move axially along its own axis (such as Figure 2 The moving speed v is in the direction of the arrow), and at the same time, the pipe unit also needs to rotate around its own axis (for example Figure 2 The shielding mechanism 4 of the present invention only needs to ensure that it moves synchronously with the tubular unit along the axial direction of the tubular unit, so that a stable shielding area 400 can be formed outside the predetermined area of the tubular unit.

[0032] In a preferred embodiment, the tubing unit includes a first tubing 100 and a second tubing 200 connected to each other via a connector 300. The shielding mechanism 4 is capable of shielding the connector 300 and at least a portion of the first tubing 100 and at least a portion of the second tubing 200 on either side thereof. In this manner, the shielding system of the present invention can shield the ends of anti-corrosion pipes on a production line, thereby ensuring that a sufficient non-coated area is reserved at the ends of the anti-corrosion pipes during production.

[0033] Preferably, the connector 300 connects the first pipe 100 and the second pipe 200 by plugging, and when the first pipe 100 and the second pipe 200 are connected by the connector 300, the first pipe 100 and the second pipe 200 hardly rotate relative to each other. It should be noted that the shielding system of the present invention can be applied not only to the production of FBE anti-corrosion pipes, but also to the production of 3PE anti-corrosion pipes. When it is applied to the production of FBE anti-corrosion pipes, since only epoxy powder spraying is required, it is only necessary to connect the first pipe 100 and the second pipe 200 by the connector 300 to ensure that the two are in the axial direction ( Figure 1 Synchronous movement in the ox direction (in the middle) is sufficient, and rotation of the first and second pipes 100, 200 is not required. However, when applied to the production of 3PE anti-corrosion steel pipes, after epoxy powder coating, the copolymer adhesive layer and the polyethylene layer are bonded and wound. To ensure bonding and winding quality, the first and second pipes 100, 200 must barely rotate relative to each other. It should be understood that "slight relative rotation" does not necessarily mean absolute non-rotation. Even slight rotation, as long as it does not affect bonding and winding quality, is considered to be within the scope of protection of the present invention.

[0034] In a preferred embodiment, a production channel 102 is formed on the powder spraying chamber frame 1. The first mounting plate 2 is at least partially located within the production channel 102 and can be raised and lowered within the production channel 102. The shielding mechanism 4 is disposed below the first mounting plate 2 and can be moved from the upstream side of the powder spraying chamber frame 1 through the production channel 102 to the downstream side of the powder spraying chamber frame 1 during the synchronous movement. The pipe unit is located within the production channel 102, which is in communication with the powder spraying chamber. In this manner, the shielding mechanism 4 is ensured to pass through the powder spraying chamber while achieving the synchronous movement.

[0035] Further preferably, an observation window 101 is provided on at least one side of the powder spraying chamber frame 1. A transparent material layer is provided at the observation window 101, so that the conditions within the powder spraying chamber and the production channel 102 can be viewed through the observation window 101, facilitating an operator's understanding of the powder spraying status. Referring to the figure, the observation window 101 extends, for example, in a direction perpendicular to the pipe unit, such as the oy direction.

[0036] In a preferred embodiment (see Figure 3), the first mounting plate 2 extends at least partially to the outside of the powder spraying chamber frame 1 along the upstream and downstream sides of the powder spraying chamber frame 1. It should be noted that when the shielding mechanism 4 forms a shield and performs the synchronous movement, its movement path needs to be transferred from the upstream side to the downstream side of the powder spraying chamber frame 1. In order to ensure that the shielding mechanism 4 has completed the formation of the shielding shape before entering the powder spraying chamber frame 1, the first mounting plate 2 needs to be extended to the upstream side by a certain distance (such as Figure 3 (as shown) to provide the necessary pre-action space for the shielding mechanism 4 positioned below it. This extended design ensures that the shielding mechanism 4 completes its initial shielding action before entering the production passage 102. Similarly, to ensure that the shielding mechanism 4 passes completely through the production passage 102, the first mounting plate 2 also extends downstream a certain distance to ensure that the shielding mechanism 4 has moved to the predetermined position downstream of the powder spraying chamber frame 1 when shielding is completed. Preferably, the downstream extension distance of the first mounting plate 2 is equal to the upstream extension distance.

[0037] In order to better achieve the purpose of the present invention, the powder spraying chamber frame 1 includes a left frame and a right frame, and there is a gap 104 between the left frame and the right frame. At the position of the gap 104, the left frame and the right frame are connected by a transition portion 103. The production channel 102 runs through the left frame, the right frame and the transition portion 103. A first cavity and a second cavity are formed in the left frame and the right frame respectively. A powder spraying cavity is formed in the transition portion 103 (the powder spraying cavity is also part of the production channel 102). The first cavity, the powder spraying cavity and the second cavity together constitute a powder spraying chamber in the powder spraying chamber frame 1, and a nozzle for spraying epoxy powder is arranged in the powder spraying cavity. During the production process of FBE anti-corrosion pipes and 3PE anti-corrosion pipes, before the powder spraying operation, the pipe unit has been heated to a predetermined temperature by medium frequency heating and other methods, and the epoxy powder will only be sintered when it is sprayed onto the surface of the pipe unit. In other cases, the epoxy powder will remain in its powder state. During the powder spraying process, a lot of epoxy powder cannot be sprayed onto the surface of the pipe unit. In this way, the epoxy powder that is not sprayed onto the surface of the pipe unit can be recovered through the first cavity and the second cavity on the left and right sides of the powder spraying cavity. This also avoids the problem of epoxy powder escaping to the outside of the powder spraying chamber frame 1, causing waste of raw materials, thereby saving costs.

[0038] In a preferred embodiment, the lifting mechanism 3 includes a lifting rod 5 and a first power unit 6. The lower end of the lifting rod 5 is fixedly connected to the top surface of the first mounting plate 2. The lifting rod 5 can move in the vertical direction under the action of the first power unit 6 to achieve vertical lifting of the first mounting plate 2. This lifting method is very common in the prior art and will not be described in detail here.

[0039] In a further preferred embodiment, see Figure 3 and Figure 7Two support rods 25 are respectively provided within the left and right frames. The two support rods 25 within the same frame are fixedly connected at their tops by a second beam 23. The support rods 25 between the left and right frames are fixedly connected at their tops by a first beam 22. A suspension mechanism 24 is fixedly mounted on the second beam 23. The lifting rod 5 is suspended on the suspension mechanism 24 for vertical movement. Each support rod 25 is fitted with a guide block 26, which is fixedly connected to the first mounting plate 2. This arrangement ensures smoother vertical movement of the first mounting plate 2. Furthermore, the coordination between the suspension mechanism 24 and the lifting rods 5 can be implemented using a gear rack, a hydraulic telescopic rod, or other similar mechanisms. The lifting rod 5 can also be more than a single rod; for example, it can be a piston structure, with a piston cylinder fixedly connected to the suspension mechanism 24 and a piston rod fixedly connected to the first mounting plate 2. The piston drives the first mounting plate 2 vertically upward and downward. The above are some specific implementations of the lifting mechanism 3, which are common in the prior art and are not key to the present invention, so they will not be described in detail here.

[0040] In a preferred embodiment, the shielding mechanism 4 includes a second mounting plate 7, a shielding assembly and a synchronous rolling mechanism, wherein a first slide rail unit 11 is provided at the bottom of the first mounting plate 2, and the first slide rail unit 11 extends along the upstream and downstream directions. The second mounting plate 7 is slidably arranged below the first mounting plate 2 through the first slide rail unit 11, and the shielding assembly and the synchronous rolling mechanism are both fixedly arranged below the second mounting plate 7. The shielding assembly includes a baffle 9, and the shielding assembly uses the baffle 9 to shield the predetermined area of the pipe unit; the synchronous rolling mechanism includes a third power unit 14, an arm unit 19 and a roller 20, wherein the rotation axis of the roller 20 is parallel to the axis of the pipe unit, the output end of the third power unit 14 is connected to one end of the arm unit 19, and the other end of the arm unit 19 is connected to the roller 20. The third power unit 14 can drive the arm unit 19 to move, thereby pressing the roller 20 against the surface of the pipe unit. Through such an arrangement, when the roller 20 is pressed against the surface of the tube unit, since the tube unit itself rotates and moves along its axial direction, the roller 20 is subjected to friction from the circumferential tangential direction of the tube unit and friction along the axial direction of the tube unit. The friction in the circumferential tangential direction drives the roller 20 to rotate, while the friction along the axial direction of the tube unit acts on the synchronous rolling mechanism, thereby driving the shielding mechanism 4 to slide along the first slide rail unit 11, realizing synchronous axial movement of the shielding mechanism 4 and the tube unit, so that the baffle 9 can always effectively shield the predetermined area of the tube unit.

[0041] Further preferred, see Figure 5 and Figure 6, the synchronous rolling mechanism also includes a support plate unit 17, a first hinge unit 18 and a second hinge unit 21. The support plate unit 17 is a "ㄇ"-shaped structure, which includes a horizontal plate at the top and side plates on both sides of the horizontal plate. The synchronous rolling mechanism is fixedly connected to the second mounting plate 7 through the horizontal plate. The third power unit 14 and the arm unit are rotatably arranged between the two side plates. The output end of the third power unit 14 is hinged to one end of the arm unit 19 through the second hinge unit 21. The middle part of the arm unit 19 is hinged to the two side plates through the first hinge unit 18. The roller 20 is provided at the end of the arm unit 19 away from the second hinge unit 21. Preferably, the arm unit 19 is bent in a V shape. Bending is a structural design, the purpose of which is to allow the roller 20 to be pressed against the upper surface of the pipe unit as much as possible when the third power unit 14 drives the arm unit 19 to move, for example Figure 5 As shown, this can ensure the stability of the roller 20 during rolling, thereby allowing the synchronous rolling mechanism to slide stably.

[0042] In a preferred embodiment, the shielding assembly further comprises a shielding body, a second slide rail unit 12 and a second power unit 13. The second slide rail unit 12 is arranged at the bottom of the second mounting plate 7 and extends in a direction perpendicular to the pipe unit ( Figure 1 The top of the shielding body is slidably connected to the second slide rail unit 12. The second power unit 13 is used to drive the shielding body to slide along the second slide rail unit 12. The bottom of the shielding body is connected to the baffle 9. This arrangement allows the baffle 9 to move closer to or further away from the pipe unit in the oy direction under the action of the second power unit 13. This facilitates adjustment for pipes of different sizes and ensures that the baffle 9 blocks the surface near the predetermined area.

[0043] To better achieve the objectives of the present invention, the barrier assembly further includes a lifting column 27 and an auxiliary unit 28. The lifting column 27 is in transmission connection with the baffle 9 (e.g., via a screw drive, cylinder drive, etc.). The auxiliary unit 28 includes a power assembly (note, not the second power assembly 13), which is used to drive the lifting column 27 and, in turn, the baffle 9 vertically. It should be understood that the baffle 9's elevation is controlled by two components: one component, which is driven by the lifting mechanism 3 to raise and lower the first mounting plate 2, and this component is equivalent to coarse adjustment. The other component, which is driven by the power assembly to drive the lifting column 27, is equivalent to fine adjustment. This arrangement is primarily intended to ensure that the baffle 9 accurately blocks the intended area.

[0044] To better achieve the objectives of the present invention, auxiliary unit 28 also includes a vacuum suction assembly. Baffle 9 is provided with a plurality of suction ports on the side facing the nozzle in the powder spraying chamber, and these ports are connected to the vacuum suction assembly. When shielding mechanism 4 moves along production channel 102 and reaches the nozzle position in the powder spraying chamber, the distance between the nozzle and baffle 9 is small. Epoxy powder from the nozzle is likely to splash around when it hits baffle 9. The vacuum suction assembly can remove this epoxy powder, thus preventing powder splashing.

[0045] To better achieve the objectives of the present invention, a rack 10 is further provided at the bottom of the first mounting plate 2, extending in the upstream and downstream directions. The shielding mechanism 4 also includes a gear 15 and a fourth power unit 16. The gear 15 meshes with the rack 10, and the fourth power unit 16 is used to drive the gear 15 to rotate. An overrunning clutch is also provided between the output end of the fourth power unit 16 and the gear 15 (common overrunning clutches, such as bicycle flywheels, can achieve self-clutching functions according to changes in rotational direction. The relevant principles and structures belong to the scope of the prior art and will not be described in detail here). When the shielding mechanism 4 moves from upstream to downstream along the first mounting plate 2, the overrunning clutch allows the gear 15 to rotate freely, allowing the shielding mechanism 4 to slide downstream due to the friction force applied to the roller 20 along the axis of the tubular unit without the need for the fourth power unit 16 to operate. When the shielding mechanism 4 needs to move from downstream to upstream, the fourth power unit 16 is activated, driving the gear 15 to rotate via the overrunning clutch. The engagement of the gear 15 with the rack 10 allows the shielding mechanism 4 to slide in the reverse direction. This design can not only accurately control the position of the shielding mechanism 4, but also reduce power consumption, optimize the operating efficiency of the equipment, and make the movement of the shielding mechanism 4 more flexible. Preferably, the first slide rail unit 11 includes two parallel slide rails, and the rack 10 is located between the two slide rails.

[0046] In order to better achieve the purpose of the present invention, the bottom of the first mounting plate 2 is also provided with an initial position and an end position for limiting the movement of the shielding mechanism 4 (for example, a corresponding mechanical stop block is provided on the first slide rail unit 11, etc.). Preferably, a first sensor and a second sensor are provided at the initial position and the end position, respectively, and the fourth power unit 16 is actuated according to the signals of the first sensor and the second sensor (to be precise, the signals detected that the shielding mechanism 4 has reached the corresponding position); when the first sensor detects that the shielding mechanism 4 has reached the initial position, the fourth power unit 16 stops actuating, and when the second sensor detects that the shielding mechanism 4 has reached the end position, the fourth power unit 16 is started to work, so that the shielding mechanism 4 moves toward the initial position and returns to the initial position. Furthermore, a third sensor is provided at the initial position, and the third sensor is used to identify the connector 300. The third power unit 14 can act according to the signal of the second sensor and the signal of the third sensor; when the third sensor detects and identifies the connector 300, the third power unit 14 is started, so that the roller 20 of the synchronous rolling mechanism is pressed against the surface of the pipe unit, thereby realizing the synchronous movement of the shielding mechanism 4 following the pipe unit along its axial direction; when the second sensor detects that the shielding mechanism 4 reaches the end position, the third power unit 14 stops working, and the roller 20 of the synchronous rolling mechanism is disengaged from the surface of the pipe unit.

[0047] In a preferred embodiment, in the upstream and downstream directions ( Figure 1 Specifically, when the baffle 9 blocks the pipe unit to form a blocking area 400, the roller 20 is within the coverage of the blocking area 400. Since the pipe unit is rotating, the roller 20 is within the coverage of the blocking area 400. Figure 2 The shielding area 400 is located at a position where the entire circumference of the pipe unit is covered by the shielding area 400. This arrangement allows a certain deviation distance L ( Figure 3 For visual clarity, the deviation distance L is drawn too large and does not correspond to the coverage of the shielded area 400, which is different from the actual situation. However, the deviation distance L should not be too large. With this arrangement, when the roller 20 is pressed against the pipe unit, it always remains in the non-coated area, without affecting the epoxy powder in the coated area and thus the quality of the anti-corrosion pipe.

[0048] It should also be noted that while the shielding system of the present invention can be applied to the production of FBE and 3PE pipes, in actual production, it is rarely used for FBE pipes. This is because, compared to our previously invented pipe end connector (application number CN202410749640.6), the shielding system consumes more energy, making it unnecessary for FBE pipe production. However, it should be understood that its application in FBE pipe production also falls within the scope of protection of the present invention.

[0049] However, the aforementioned pipe-end connectors are not applicable to 3PE anti-corrosion pipes. Prior art still primarily utilizes shielding materials such as kraft paper and tape during the production of 3PE anti-corrosion pipes. This not only complicates the production process but also results in significant waste of coating material and the generation of large amounts of waste. However, when the shielding system of the present invention is applied to 3PE anti-corrosion pipe production, the non-coated areas can be formed without the need for kraft paper or other materials. Furthermore, the subsequent bonding of the copolymer adhesive layer and the winding of the polyethylene layer will not be adversely affected. In addition, after the production is completed, the copolymer adhesive layer and the polyethylene layer here can be cut off by a cutting device to obtain a finished 3PE anti-corrosion pipe with a non-coated area. Since there is no epoxy powder on the cut copolymer adhesive layer and the polyethylene layer (if kraft paper is used, a large amount of epoxy powder will be dissolved on the kraft paper and then combined with the copolymer adhesive layer), it can also be recycled (the existing kraft paper pasting solution cannot be reused because the epoxy powder melted on the surface of the kraft paper has contaminated the copolymer adhesive layer). Therefore, the application of the shielding system of the present invention to the production of 3PE anti-corrosion pipes will have great advantages.

[0050] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A shielding system comprising a pipe unit, a powder spraying chamber frame (1), a first mounting plate (2) and a shielding mechanism (4), characterized in that: The pipe unit passes through a powder spraying chamber frame (1), a powder spraying chamber is formed in the powder spraying chamber frame (1), and a shielding mechanism (4) is provided on the first mounting plate (2). The shielding mechanism (4) can shield a predetermined area of the pipe unit and simultaneously move along the axial direction of the pipe unit to pass through the powder spraying chamber while shielding, thereby preventing powder from the powder spraying chamber from being sprayed onto the predetermined area. The shielding mechanism (4) includes a second mounting plate (7), a shielding assembly, and a synchronous rolling mechanism. The second mounting plate (7) is slidably arranged below the first mounting plate (2). The shielding assembly and the synchronous rolling mechanism are both arranged below the second mounting plate (7). The synchronous rolling mechanism includes a third power unit (14), an arm unit (19), and a roller (20). The third power unit (14) can drive the arm unit (19) to move, thereby pressing the roller (20) against the surface of the pipe unit. When the roller (20) is pressed against the surface of the pipe unit, the roller (20) is subjected to friction from the circumferential tangent direction of the pipe unit and friction along the axial direction of the pipe unit. The friction in the circumferential tangent direction drives the roller (20) to rotate, and the friction along the axial direction of the pipe unit acts on the synchronous rolling mechanism, thereby realizing synchronous axial movement of the shielding mechanism (4) and the pipe unit.

2. A shielding system according to claim 1, characterized in that: The pipe unit comprises a first pipe (100) and a second pipe (200) connected to each other, the first pipe (100) and the second pipe (200) being connected via a connector (300), and the shielding mechanism (4) is capable of shielding the connector (300) and at least a portion of the first pipe (100) and at least a portion of the second pipe (200) on both sides thereof.

3. A shielding system according to claim 2, characterized in that: The first tube (100) and the second tube (200) do not rotate relative to each other when they are connected via the connector (300).

4. The shielding system according to claim 1, wherein: A production channel (102) is formed on the powder spraying chamber frame (1); a first mounting plate (2) is at least partially located in the production channel (102) and can be raised and lowered in the production channel (102); a shielding mechanism (4) is arranged below the first mounting plate (2) and can be moved from the upstream side of the powder spraying chamber frame (1) to the downstream side of the powder spraying chamber frame (1) through the production channel (102) during the synchronous movement; and the pipe unit is located in the production channel (102).

5. A shielding system according to claim 4, characterized in that: The powder spraying chamber frame (1) comprises a left frame and a right frame, the left frame and the right frame are connected via a transition portion (103), a production channel (102) passes through the left frame, the right frame and the transition portion (103), a first cavity and a second cavity are formed in the left frame and the right frame respectively, a powder spraying cavity is formed in the transition portion (103), the first cavity, the powder spraying cavity and the second cavity together constitute the powder spraying chamber, and a nozzle for spraying epoxy powder is arranged in the powder spraying cavity.

6. The shielding system according to claim 1, characterized in that: The rotation axis of the roller (20) is parallel to the axis of the pipe unit. The output end of the third power unit (14) is connected to one end of the arm unit (19), and the other end of the arm unit (19) is connected to the roller (20).

7. The shielding system according to claim 1, characterized in that: A rack (10) is also provided at the bottom of the first mounting plate (2), and the shielding mechanism (4) further includes a gear (15) and a fourth power unit (16), the gear (15) being meshed with the rack (10), and the fourth power unit (16) being used to drive the gear (15) to rotate. An overrunning clutch is also provided between the output end of the fourth power unit (16) and the gear (15), and when the shielding mechanism (4) moves from the upstream side to the downstream side of the powder spraying chamber frame (1), the overrunning clutch puts the gear (15) in a free rotation state without the need for the fourth power unit (16) to operate; when the shielding mechanism (4) needs to move from the downstream side to the upstream side, the fourth power unit (16) is started, and the gear (15) is driven to rotate by the overrunning clutch, and the shielding mechanism (4) is enabled to slide in the reverse direction by meshing the gear (15) with the rack (10).

8. The shielding system according to claim 1, wherein: The bottom of the first mounting plate (2) is also provided with an initial position and an end position for limiting the movement of the shielding mechanism (4), and a first sensor and a second sensor are respectively provided at the initial position and the end position. The fourth power unit (16) operates according to the signals of the first sensor and the second sensor; when the first sensor detects that the shielding mechanism (4) has reached the initial position, the fourth power unit (16) stops operating; when the second sensor detects that the shielding mechanism (4) has reached the end position, the fourth power unit (16) is started to operate, so that the shielding mechanism (4) moves toward the initial position and returns to the initial position.

9. Application of a shielding system according to any one of claims 1 to 8 in the production of 3PE anti-corrosion pipes.

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