Combined structure spiral welded steel pipe and continuous production equipment thereof

Abstract

The utility model relates to a spiral welded steel pipe with a combined structure and continuous production equipment thereof.The steel pipe is composed of an inner-layer steel pipe wall and an outer-layer steel pipe wall, the inner-layer steel pipe wall and the outer-layer steel pipe wall are formed by spirally rolling and welding an upper steel belt and a lower steel belt, a vertical steel belt is welded between the upper steel belt and the lower steel belt, and after a pipe body is manufactured through welding, a cavity is formed between the upper steel belt and the lower steel belt; the vertical steel belt is provided with a first welding seam which is formed with the upper steel belt and is positioned on the wall surface of the upper steel belt, the vertical steel belt is provided with a second welding seam which is formed with the lower steel belt and is positioned on the wall surface of the steel belt, and the first welding seam and the second welding seam are positioned inside the cavity. By means of the multi-welding-seam design, high-strength connection among the three parts is guaranteed, large mechanical loads can be borne, the stability and durability of the structure can be kept, secondary reinforcement is achieved through combination with vertical steel belt fillet welding seams, the strength of the welding seams is remarkably improved, and the welding seams which are not exposed are attractive.

Description

Technical Field

[0001] The present invention relates to the technical field of steel pipe welding, in particular to a combined structure spiral welded steel pipe and continuous production equipment thereof. Background Art

[0002] This application designs a composite structural steel pipe, reference application number: 202211023603.4, title: A composite structural wall large diameter spiral welded steel pipe and its manufacturing method prior application, the steel pipe is made of a continuous composite steel strip after spiral rolling and welding, wherein the composite steel strip is made of two upper and lower flat steel strips with a vertical steel strip (reinforcement rib) welded in the middle, such as Figure 1 and 2 As shown. During the spiral rolling process of the above-mentioned composite steel strip, the vertical steel strip and the lower steel strip (outer steel strip) will produce large plastic deformation, and the following problems will occur: 1. After the composite steel strip composed of the upper steel strip, the lower steel strip and the vertical steel strip are directly welded together, the cross-sectional moment is much larger than that of the single-layer steel plate, and the power requirement of the equipment is too high; 2. After the composite steel strip is welded together, when rolling, the vertical steel strip is subjected to too much radial pressure due to the tensile deformation of the outer steel strip when rolling, which will cause unstable buckling, especially the pressure of the lower steel strip (outer steel strip) on the vertical steel strip during plastic deformation and stretching; 3. The lower steel strip will have a large extension and large plastic deformation, and the weld between the lower steel strip and the vertical steel strip will be stretched and damaged; 4. After the tube is formed, the connection between the lower steel strip and the vertical steel strip will form a protruding spiral pattern, and the surface of the corrugated tube will be uneven, such as Figure 3 As shown; 5. The upper steel belt (inner steel belt) shrinks severely. When the upper steel belt is thin, it may buckle and wrinkle.

[0003] Tests have shown that using penetration welding to weld the pipe wall steel strip to the vertical steel strip from the outside of the composite steel strip makes it difficult to penetrate the gap between the vertical steel strip and the upper or lower steel strip, and it is also difficult to weld correctly, which affects the weld strength. If the entire steel strip is cut into multiple narrow steel strips to correspond to the vertical steel strips, there will be too many welds, affecting the overall performance of the steel strip. Utility Model Content

[0004] Based on this, it is necessary to provide a combined structure spiral welded steel pipe with high welding strength and good sealing and its continuous production equipment to address the above technical problems.

[0005] A composite structure spiral welded steel pipe, the steel pipe consists of two layers of inner and outer steel pipe walls, the inner and outer pipe walls are formed by spirally rolling and welding an upper steel strip and a lower steel strip, a vertical steel strip is welded between the upper and lower steel strips, after welding the steel pipe, a cavity is formed between the upper and lower steel strips, the vertical steel strip has a first weld formed with the upper steel strip and located on the wall surface of the upper steel strip, and the vertical steel strip has a second weld formed with the lower steel strip and located on the wall surface of the lower steel strip, the first weld and the second weld are both located inside the cavity.

[0006] In one embodiment, the butt spiral welds between the adjacent upper steel strips of the front and rear turns and the butt spiral welds between the adjacent lower steel strips of the front and rear turns are staggered in the axial direction of the steel pipe.

[0007] In one embodiment, the butt spiral welds between the adjacent upper steel strips of the front and rear circles and the butt spiral welds between the adjacent lower steel strips of the front and rear circles are both located in the plane of the ends of the vertical steel strips.

[0008] In one embodiment, the end of the vertical steel strip is surrounded by at least three welds, and the three welds include: a butt spiral weld between the front and rear adjacent steel strips, the first weld or the second weld.

[0009] In one embodiment, in the axial direction of the steel pipe, the butt spiral weld is located between the first weld or the second weld.

[0010] In one embodiment, the number of vertical steel strips corresponding to each upper steel strip or the lower steel strip is greater than or equal to two.

[0011] In one embodiment, shear nails are respectively provided on the upper steel belt, the lower steel belt and / or the vertical steel belt.

[0012] A continuous production equipment for combined structure spiral welded steel pipes is used to process combined structure spiral welded steel pipes such as the above-mentioned. The production equipment includes a reeling mechanism, a delivery mechanism, a spiral rolling mechanism and a welding mechanism for welding the upper steel strip and the vertical steel strip. The reeling mechanism is used to release the upper steel strip. The first composite steel strip is delivered by the delivery mechanism, and the vertical steel strip is rolled outward by the spiral rolling mechanism. The welding mechanism welds the spiral joint between the upper steel strip of the first composite steel strip and the upper steel strip of the previous section to form a butt spiral weld. The lower steel strip guide is fitted with the vertical steel strip of the first composite steel strip.

[0013] In one embodiment, the spiral rolling mechanism includes a leading roller, a pressing roller and a rolling roller behind the delivery mechanism. The first composite steel strip is delivered by the delivery mechanism and rolled outward by the spiral rolling mechanism. The welding mechanism welds the spiral joint between the upper steel strip of the first composite steel strip that has just passed the pressing roller position and the upper section of the steel strip that has become the tube body. The lower steel strip is guided by the guide roller and fitted with the vertical steel strip of the first composite steel strip that has passed the leading roller. When the fitting point passes the pressing roller, that is, the plastic deformation point of the first composite steel strip, the joint between the upper vertical steel strip and the lower steel strip of the first composite steel strip is welded by the welding mechanism, and continuously spirally rolled and welded.

[0014] In one embodiment, the welding gun of the welding mechanism extends into the cavity between the first composite steel strip and the lower steel strip to weld the seam between the vertical steel strip and the lower steel strip.

[0015] In one embodiment, the guide roller and the lower steel belt are arranged at the lower side of the spiral winding mechanism, and the first composite steel belt is positioned after the first composite steel belt completes the full-circle spiral winding. The lower steel belt is led out through the guide roller and attached to the first composite steel belt after the full-circle winding is completed, and the joint between the first composite steel belt and the lower steel belt is welded.

[0016] In one embodiment, the guide roller and the lower steel belt are arranged above the tube body on which the first composite steel belt has been spirally rolled. The lower steel belt is led out through the guide roller and attached to the first composite steel belt that has been rolled, and the joint between the first composite steel belt and the lower steel belt is welded.

[0017] In one embodiment, the production equipment includes a rotating device, the first composite steel strip is rolled into a tube blank separately, the tube blank is placed on the rotating device, and then the lower steel strip is attached to the outside of the tube blank, and the welding mechanism welds the welds between the tube blank, the first composite steel strip and the lower steel strip.

[0018] In one embodiment, the guide roller is composed of a plurality of rollers with adjustable angles, the angle of the rollers matches the forward direction of the first composite steel strip, the upper steel strip is close to the outer wall of the roller, the rollers are arranged at intervals, and the gaps at the intervals are used to pass and clamp the guide vertical steel strip.

[0019] In one embodiment, the rolling roller is composed of a plurality of rollers with adjustable angles, the angles of the rollers match the forward direction of the first composite steel strip, the upper steel strip is close to the outer wall of the roller, the rollers are arranged at intervals, and the gaps at the intervals are used to pass and clamp the guide vertical steel strips and assist in rolling the vertical steel strips.

[0020] In one embodiment, the continuous production equipment further includes a clamping and guiding device for stabilizing the vertical steel strip, one or more of which are arranged in the circumferential direction of the spirally rolled first composite steel strip.

[0021] In one embodiment, the clamping guide device includes a guide shaft, and the guide shaft is provided with a clamping guide wheel corresponding to the vertical steel strip on the first composite steel strip through a guide bearing sleeve, and a positioning sleeve is set between adjacent clamping guide wheels. The outer periphery of the clamping guide wheel is provided with a clamping groove for the vertical steel strip to be embedded, and the angle of the clamping guide device matches the angle of the first composite steel strip.

[0022] In one embodiment, the clamping guide device is composed of a plurality of rollers with adjustable angles, the angles of the rollers match the forward direction of the first composite steel strip, the rollers are arranged at intervals, and the gaps at the intervals are used to clamp and guide the vertical steel strip.

[0023] In one embodiment, a micro-protrusion structure is provided on the shaft roller of the delivery mechanism, and the position of the micro-protrusion structure is aligned with the upper steel strip at the top position of the vertical steel strip on the first composite steel strip.

[0024] In one embodiment, after the combined structure spiral welded steel pipe is formed, the spiral weld of the upper steel strip is staggered with the spiral weld of the lower steel strip.

[0025] In one embodiment, the width of the lower steel strip matches the size of the first composite steel strip.

[0026] A method for manufacturing a composite structure spiral welded steel pipe, used for processing the composite structure spiral welded steel pipe, comprises the following steps:

[0027] S1. Unwinding an upper steel strip from a steel coil and welding vertical steel strips to the upper steel strip to form a first composite steel strip having a first weld seam;

[0028] S2. Flip the first composite steel strip so that the vertical steel strip faces downward, and then deliver it to the spiral coiling mechanism by the delivery mechanism. The vertical steel strip serves as the inner coil and is coiled outward.

[0029] S3, welding the spiral seam between the upper steel strip of the first composite steel strip that has just passed the position directly below the rounding roller and the upper steel strip of the previous section that has become the pipe body;

[0030] S4, guiding the lower steel strip through the guide rollers and laminating it with the first composite steel strip;

[0031] S5. After the lower steel strip is bonded to the first composite steel strip and the bonding point passes through the rounding roller, a welding gun is inserted into the cavity between the upper and lower steel strips and the vertical steel strip to weld a second weld in the welding cavity;

[0032] S6. A spiral butt weld is completed between the rolled lower steel strip and the upper lower steel strip that has become the pipe body at the top of the pipe body.

[0033] In one embodiment, step S3 further includes: S7, the first composite steel strip is separately rolled into a tube blank, the tube blank is cut into a standard tube segment tube blank, the lower steel strip is attached to the outside of the standard tube segment tube blank, the standard tube segment tube blank is rotated and the weld between the tube blank, the first composite steel strip and the lower steel strip is welded simultaneously.

[0034] This application has the following technical effects:

[0035] 1) The welds between the upper steel belt, the lower steel belt and the vertical steel belt ensure a high-strength connection between the three, which can not only withstand large mechanical loads but also maintain the stability and durability of the structure.

[0036] 2) The spiral weld between the front and rear steel strips forms a continuous, spiral weld through a carefully designed welding path. This not only provides structural continuity and integrity, but also achieves secondary reinforcement through combination with the vertical steel strip fillet welds, significantly improving the strength of the weld, making the entire structure more stable and able to withstand greater external force impacts, while extending the service life of the structure.

[0037] 3) There are three spiral welds between the front and rear steel belts. This multiple weld design greatly improves the sealing of the welds, and each weld provides additional sealing protection for the entire structure.

[0038] 4) The weld between the vertical steel strip and the inner and outer pipe walls is designed inside the cavity interlayer between the inner and outer pipe walls, avoiding the use of penetration welding. The welding is accurate and efficient. This design prevents the weld from being exposed, thereby maintaining the aesthetic appearance of the pipe body. It also helps to protect the weld from direct erosion by the external environment and extend the overall service life of the welded steel pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a cross-sectional view of a composite steel strip welded as a whole;

[0040] Figure 2 Schematic diagram of spirally rolled composite steel strip welded into a whole;

[0041] Figure 3 Schematic diagram of the convex spiral structure;

[0042] Figure 4 This is a structural diagram of a continuous production equipment form according to an embodiment of the present application;

[0043] Figure 5 This is a schematic top view of the intersection of the guide roller and the first composite steel strip structure according to one embodiment of the present application;

[0044] Figure 6 This is a schematic structural diagram of a clamping guide device according to an embodiment of the present application;

[0045] Figure 7 This is a structural diagram of a second continuous production equipment form of an embodiment of the present application;

[0046] Figure 8 This is a structural diagram of a continuous production equipment form 3 of an embodiment of the present application;

[0047] Figure 9 This is a schematic structural diagram of a first composite steel strip according to an embodiment of the present application;

[0048] Figure 10 This is a schematic structural diagram of the first composite steel belt, the lower steel belt, and the guide rollers according to an embodiment of the present application;

[0049] Figure 11 This is a schematic diagram of welding points of the first composite steel strip and the lower steel strip according to an embodiment of the present application;

[0050] Figure 12 This is a processing schematic diagram of an embodiment of the present application in which the guide rollers and the lower steel belt are positioned laterally below the roll forming mechanism;

[0051] Figure 13 A top view of a third continuous production apparatus according to an embodiment of the present application;

[0052] Figure 14 A schematic top view of a winding roller and a winding roller wheel according to an embodiment of the present application;

[0053] Figure 15 This is a schematic cross-sectional view of a steel pipe according to an embodiment of the present application;

[0054] Figure 16 Schematic diagram of a pre-deformation device for a first composite steel strip according to an embodiment of the present application.

[0055] Description of Figure Numbers:

[0056] 1. Upper steel strip; 2. Lower steel strip; 3. Vertical steel strip; 301. First weld; 302. Second weld; 303. Butt spiral weld; 4. Delivery mechanism screw; 5. Spiral winding mechanism; 501. Lead roller; 502. Pressing roller; 503. Winding roller; 6. Guide roller; 7. Guide device; 701. Guide shaft; 702. Guide bearing; 703. Guide wheel; 704. Clamping groove. DETAILED DESCRIPTION

[0057] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0058] like Figure 4 The continuous production equipment of the combined structure spiral welded steel pipe shown in the figure, the combined structure spiral welded steel pipe is formed by continuously rolling and welding a composite steel strip, and the composite steel strip is formed by welding a parallel upper steel strip 1, a lower steel strip 2 and a vertical steel strip 3 therebetween, and the upper steel strip 1 and the vertical steel strip 3 are welded to first form a first composite steel strip.

[0059] The upper steel strip 1 and the lower steel strip 2 have the same size, so that the width of the lower steel strip 2 matches the size of the first composite steel strip.

[0060] The production equipment includes a reeling mechanism, a delivery mechanism 4, a spiral rolling mechanism 5 and a welding mechanism for welding the upper steel strip 1 and the vertical steel strip 3. The reeling mechanism is used to release the upper steel strip 1. The first composite steel strip is delivered by the delivery mechanism 4, and the vertical steel strip is rolled outward by the spiral rolling mechanism 5. The welding mechanism welds the spiral joint between the upper steel strip 1 of the first composite steel strip and the upper steel strip of the previous section to form a butt spiral weld 303. The lower steel strip 2 is guided to fit with the vertical steel strip 3 of the first composite steel strip.

[0061] The production equipment includes a delivery mechanism 4, a spiral rolling mechanism 5, a guide roller 6 and a welding mechanism. The spiral rolling mechanism 5 includes a leading roller 501, a pressing roller 502 and a rolling roller 503 behind the delivery mechanism 4. The first composite steel strip is delivered by the delivery mechanism 4 and rolled outward by the spiral rolling mechanism 5. The welding mechanism welds the spiral joint between the upper steel strip 1 of the first composite steel strip that has just passed the pressing roller 502 and the upper steel strip of the previous section that has become the tube body. The lower steel strip 2 is guided by the guide roller 6 to fit with the vertical steel strip 3 of the first composite steel strip that has passed the leading roller 501. When the fitting point passes the pressing roller 502, that is, the plastic deformation point of the first composite steel strip, the joint between the first composite steel strip and the lower steel strip is welded by the welding mechanism, and continuously spirally rolled and welded. Figure 16 shown.

[0062] The production equipment includes a rotating device. The first composite steel strip is individually rolled into a tube blank, which is placed on the rotating device. The lower steel strip 2 is then attached to the exterior of the tube blank. The welding mechanism welds the welds between the tube blank, the first composite steel strip, and the lower steel strip 2. Furthermore, the tube blank is cut into standard tube segments, which meet commonly used specifications and dimensions.

[0063] like Figure 5 As shown, the guide roller 501 is composed of a plurality of rollers arranged at intervals and having adjustable angles. The angles thereof match the advancing direction of the first composite steel strip. The upper steel strip is in close contact with the outer walls of the rollers. The rollers are arranged at intervals, and the gaps between the rollers are used to pass through and clamp the guide vertical steel strip 3.

[0064] The winding roller 503 is composed of a plurality of rollers with adjustable angles that can be arranged at intervals. The angle thereof matches the forward direction of the first composite steel strip. The upper steel strip is close to the outer wall of the roller. The rollers are arranged at intervals. The gaps at the intervals are used to pass and clamp the guide vertical steel strip 3 and assist in winding the vertical steel strip.

[0065] like Figure 6As shown, the continuous production equipment also includes a clamping guide device 7 for stabilizing the vertical steel strips 3. One or more clamping guide devices are arranged circumferentially around the spirally wound first composite steel strip. The clamping guide device 7 includes a guide shaft 701, which is fitted with clamping guide wheels 703 corresponding to the vertical steel strips 3 on the first composite steel strip via guide bearings 702. Positioning spacers 705 are positioned between adjacent clamping guide wheels 703. The outer circumference of each clamping guide wheel 703 defines a clamping groove 704 for the vertical steel strips 3 to fit into. The angle of the clamping guide device matches the angle of the first composite steel strip.

[0066] The clamping and guiding device may also be composed of a plurality of rollers with adjustable angles, the angles of which match the advancing direction of the first composite steel strip. The rollers are arranged at intervals, and the gaps at the intervals are used to clamp and guide the vertical steel strip.

[0067] Considering that the lower steel strip is located directly below the composite steel strip being rolled, the space at this location is narrow. It is necessary to set up clamping and guiding devices to prevent deformation of the vertical reinforcement during processing, and to set up multiple welding guns to interfere with each other. In addition, the lower steel coil is directly below the rolling and forming device, and a deep pit needs to be dug to place the steel coil, which also makes it difficult to hoist the steel coil into place. In addition, the deformation and quality of the weld between the upper steel strip of the upper section of the composite steel strip and the vertical steel strip after rolling and spiral rolling cannot be inspected in real time. Secondly, after spiral rolling, the verticality of the spiral reinforcement to the inner and outer pipe walls may change, which may affect the overall performance of the structure.

[0068] Further improvements are proposed for the continuous production equipment of spiral welded steel pipes based on the above-mentioned combined structure.

[0069] One improvement: Figure 7 As shown, the guide roller 6 and the lower steel strip 2 are arranged above the tube body on which the first composite steel strip has completed spiral rolling. The lower steel strip 2 is led out through the guide roller 6 and adhered to the first composite steel strip that has completed rolling, and the joint between the first composite steel strip and the lower steel strip 2 is welded.

[0070] Improvement 2: If Figure 8 and Figure 13 As shown, the guide roller 6 and the lower steel belt 2 are arranged at the lower side of the spiral winding mechanism 5, at a position after the first composite steel belt completes the full-circle spiral winding. The lower steel belt 2 is led out through the guide roller 6 and attached to the first composite steel belt after the full-circle winding is completed, and the joint between the first composite steel belt and the lower steel belt 2 is welded.

[0071] The production method of the continuous production equipment of the combined structure spiral welded steel pipe based on the second improvement includes the following steps:

[0072] S1, unwind the upper steel strip 1 from the steel coil, and weld the vertical steel strip 3 on the upper steel strip 1 to form the first composite steel strip, such as Figure 9 As shown;

[0073] S2, turn the first composite steel strip 180 degrees, so that the vertical steel strip 3 faces downward, and then deliver it to the spiral rolling mechanism 5 by the delivery mechanism 4, with the above steel strip 1 as the inner ring and the vertical steel strip 3 rolled outward, as shown in FIG. Figure 8 、 12 , 13 and 14;

[0074] S3, welding the spiral seam between the upper steel strip 1 that has just been rolled and the upper steel strip of the previous section that has become the pipe body, such as Figure 12 As shown;

[0075] The step S3 further includes: S7, the first composite steel sheet is rolled out into a tube blank, the tube blank is cut into a standard tube segment tube blank, the lower steel strip (2) is attached to the outside of the standard tube segment tube blank, the standard tube segment tube blank is rotated, and the weld between the tube blank, the first composite steel strip and the lower steel strip (2) is welded simultaneously.

[0076] S4, the lower steel strip 2 is introduced by the guide roller 6 and is bonded to the first composite steel strip that has been rolled;

[0077] S5. After the lower steel strip 2 is bonded to the first composite steel strip and the bonding point passes through the rounding roller, a welding gun is inserted into the cavity between the upper and lower steel strips and the vertical steel strip to weld the weld seam in the cavity. Figure 12 and 13 As shown;

[0078] S6, welding is completed to complete the spiral seam between the rolled lower steel strip 2 and the upper section of the lower steel strip 2 that has become the pipe body, such as Figure 13 、 14 As shown, after the combined structure spiral welded steel pipe is formed, the spiral weld of the upper steel strip 1 and the spiral weld of the lower steel strip 2 are staggered.

[0079] See Figure 15 , Figure 15 A structural schematic diagram of a combined structure spiral welded steel pipe of an embodiment of the present application is shown, wherein the steel pipe consists of two layers of inner and outer steel pipe walls, wherein the inner and outer pipe walls are formed by spirally rolling and welding an upper steel strip 1 and a lower steel strip 2, and a vertical steel strip 3 is welded between the upper steel strip 1 and the lower steel strip 2. After welding into a pipe body, a cavity is formed between the upper steel strip 1 and the lower steel strip 2, and the vertical steel strip 3 has a first weld 301 formed with the upper steel strip 1 and located on the wall surface of the upper steel strip 1, and the vertical steel strip 3 has a second weld 302 formed with the lower steel strip 2 and located on the wall surface of the steel strip, and both the first weld 301 and the second weld 302 are located inside the cavity.

[0080] Specifically, the upper and lower steel strips 1 and 2 are arranged substantially parallel to each other in the horizontal direction, and the vertical steel strips 3 are arranged perpendicular to the upper and lower steel strips 1 and 2 in the vertical direction. The upper and lower steel strips 1, 2, and the vertical steel strips 3 form a steel pipe segment with an "I"-shaped cross-section. Multiple steel pipe segments are welded sequentially to form a steel pipe of a certain length. In step S1, the vertical steel strips 3 are welded to the upper steel strip 1 to form a first weld 301 in the cavity. In step S5, the second weld 302 is formed by welding the vertical steel strips 3 into the cavity between the upper and lower steel strips 2 and the vertical steel strips 3 using a welding torch. Specifically, the first weld 301 and the second weld 302 are fillet welds.

[0081] In one embodiment, the butt spiral weld 303 between the upper steel strips 1 adjacent to the front and rear circles and the butt spiral weld 303 between the lower steel strips 2 adjacent to the front and rear circles are staggered in the axial direction of the steel pipe. Since the upper steel strip 1 and the lower steel strip 2 are spirally rolled, the butt joints between the upper steel strips 1 of the front and rear circles or the lower steel strips 2 of the front and rear circles are spiral seams. After welding, the butt spiral welds 303 are staggered in the axial direction of the steel pipe. The staggered butt spiral welds 303 are located on different vertical steel strips 3 at the positions of the upper steel strip 1 and the lower steel strip 2, that is, only one end of the vertical steel strip 3 has a butt spiral weld 303 to avoid stress concentration at the weld on the same vertical steel strip 3. The upper steel strips 1 of adjacent circles and the lower steel strips 2 of adjacent circles are also staggered.

[0082] In one embodiment, the butt spiral welds 303 between the adjacent front and rear circles of the upper steel strips 1 and the butt spiral welds 303 between the adjacent front and rear circles of the lower steel strips 2 are both located in the plane of the end of the vertical steel strip 3.

[0083] In one embodiment, a butt joint is formed between the adjacent front and rear steel strips, and the butt joint is located in the top plane of the vertical steel strip 3. The butt joint is the gap before welding, and welding is performed along the butt joint to form a butt spiral weld 303.

[0084] In one embodiment, the axial width of the vertical steel strip 3 is greater than or equal to the axial width of the butt weld, so that the butt spiral weld 303 is located in the plane of the end of the vertical steel strip 3. Furthermore, in the axial direction, at least one of the front edge and the rear edge of the butt spiral weld 303 does not exceed the edge of the end of the vertical steel strip 3.

[0085] In one embodiment, each end of the vertical steel strip 3 is surrounded by at least three welds, including a butt spiral weld 303 between the front and rear adjacent steel strips, a first weld 301, and a second weld 302. In terms of processing technology, the first weld 301, butt spiral weld 303, and second weld 302 are welded sequentially.

[0086] In one embodiment, in the axial direction of the steel pipe, the butt spiral weld 303 is located between the first weld 301 and the second weld 302. Specifically, the butt spiral weld 303 corresponding to one side of the upper steel strip 1 is located between the first weld 301 and the second weld 302 on that side, and the butt spiral weld 303 corresponding to one side of the lower steel strip 2 is located between the first weld 301 and the second weld 302 on that side.

[0087] In one embodiment, the number of vertical steel strips 3 corresponding to each upper steel strip 1 or the lower steel strip 2 is greater than or equal to two.

[0088] In one embodiment, shear nails are respectively provided on the upper steel belt 1, the lower steel belt 2 and / or the vertical steel belt 3 to improve the strength of the steel belts.

[0089] In one embodiment, the vertical steel strip 3 is perforated.

[0090] On the other hand, a continuous production equipment for a combined structure spiral welded steel pipe is provided, which is used to process the combined structure spiral welded steel pipe as described above. The production equipment includes a delivery mechanism, a spiral rolling mechanism 5 and a welding mechanism. The first composite steel strip is delivered by the delivery mechanism, and the vertical steel strip 3 is rolled outward by the spiral rolling mechanism 5. The welding mechanism welds the spiral joint between the upper steel strip 1 of the first composite steel strip and the upper steel strip 1 of the previous section to form a butt spiral weld 303. The lower steel strip 2 is guided by the guide roller 6 to fit the vertical steel strip 3 of the first composite steel strip.

[0091] In the description of this application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0092] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, if the term "plurality" appears, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0093] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connected," "fixed," etc., should be interpreted broadly. For example, these terms may refer to fixed connections, removable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; and internal communication between two components or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0094] In this application, unless otherwise expressly specified or limited, if a first feature is described as being "above" or "below" a second feature, or similar descriptions, this may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is described as being "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is described as being "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0095] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only embodiment.

[0096] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0097] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A composite structure spiral welded steel pipe, characterized in that: The steel pipe is composed of two layers of steel pipe walls, the inner and outer layers of the steel pipe walls are formed by spirally rolling and welding an upper steel strip (1) and a lower steel strip (2), a vertical steel strip (3) is welded between the upper steel strip (1) and the lower steel strip (2), and after the steel pipe is welded, a cavity is formed between the upper steel strip (1) and the lower steel strip (2), the vertical steel strip (3) has a first weld (301) formed with the upper steel strip (1) and located on the wall surface of the upper steel strip (1), and the vertical steel strip (3) has a second weld (302) formed with the lower steel strip (2) and located on the wall surface of the lower steel strip (2), and the first weld (301) and the second weld (302) are both located inside the cavity.

2. The composite structure spiral welded steel pipe according to claim 1, characterized in that: The butt spiral welds (303) between the upper steel strips (1) adjacent to the front and rear circles and the butt spiral welds (303) between the lower steel strips (2) adjacent to the front and rear circles are staggered in the axial direction of the steel pipe.

3. The composite structure spiral welded steel pipe according to claim 1, characterized in that: The butt spiral welds (303) between the upper steel strips (1) adjacent to the front and rear circles and the butt spiral welds (303) between the lower steel strips (2) adjacent to the front and rear circles are both located in the plane of the end of the vertical steel strip (3).

4. The composite structure spiral welded steel pipe according to claim 1, characterized in that: The end of the vertical steel strip (3) is surrounded by at least three welds, and the three welds include: a butt spiral weld (303) between the front and rear adjacent steel strips, the first weld (301) or the second weld (302).

5. The composite structure spiral welded steel pipe according to claim 4, characterized in that: In the axial direction of the steel pipe, the butt spiral weld (303) is located between the first weld (301) or the second weld (302).

6. The composite structure spiral welded steel pipe according to claim 1, characterized in that: The number of vertical steel strips (3) corresponding to each upper steel strip (1) or each lower steel strip (2) is greater than or equal to two.

7. The composite structure spiral welded steel pipe according to claim 1, characterized in that: Shear nails are respectively provided on the upper steel belt (1), the lower steel belt (2) and / or the vertical steel belt (3).

8. A continuous production equipment for composite structure spiral welded steel pipes, characterized in that: The invention is used for processing the composite structure spiral welded steel pipe as described in any one of claims 1 to 7, wherein the production equipment comprises a reeling mechanism, a delivery mechanism (4), a spiral rolling mechanism (5) and a welding mechanism for welding the upper steel strip (1) and the vertical steel strip (3), wherein the reeling mechanism is used for releasing the upper steel strip (1), the first composite steel strip is delivered by the delivery mechanism (4), and the vertical steel strip is rolled outward by the spiral rolling mechanism (5), and the welding mechanism welds the spiral joint between the upper steel strip (1) of the first composite steel strip and the upper steel strip of the previous section to form a butt spiral weld (303), and the lower steel strip (2) is guided to fit with the vertical steel strip (3) of the first composite steel strip.

9. The continuous production equipment for composite structure spiral welded steel pipe according to claim 8, characterized in that: The spiral rolling mechanism (5) comprises a leading roller (501), a pressing roller (502) and a rolling roller (503) behind the delivery mechanism (4); the first composite steel strip is delivered by the delivery mechanism (4), and the vertical steel strip is rolled outward by the spiral rolling mechanism (5); the welding mechanism welds the spiral joint between the upper steel strip (1) of the first composite steel strip that has passed the pressing roller (502) and the upper steel strip of the previous section that has become the tube body; the lower steel strip (2) is guided by the guide roller (6) to fit with the vertical steel strip (3) of the first composite steel strip that has passed the leading roller (501); when the fitting point passes the pressing roller (502), that is, the plastic deformation point of the first composite steel strip, the joint between the upper vertical steel strip (3) of the first composite steel strip and the lower steel strip is welded by the welding mechanism, and the spiral rolling and welding are continued.

10. The continuous production equipment for composite structure spiral welded steel pipe according to claim 8, characterized in that: The welding gun of the welding mechanism extends into the cavity between the first composite steel strip and the lower steel strip (2) to weld the joint between the vertical steel strip (3) and the lower steel strip (2).

11. The continuous production equipment for composite structure spiral welded steel pipe according to claim 9, characterized in that: The guide roller (6) and the lower steel strip (2) are arranged laterally below the spiral rolling mechanism (5), at a position where the first composite steel strip has completed full-circle spiral rolling. The lower steel strip (2) is led out through the guide roller (6) and attached to the first composite steel strip after the full-circle rolling is completed, and the joint between the first composite steel strip and the lower steel strip (2) is welded.

12. The continuous production equipment for composite structure spiral welded steel pipe according to claim 9, characterized in that: The guide roller (6) and the lower steel strip (2) are arranged above the tube body on which the first composite steel strip has been spirally rolled; the lower steel strip (2) is led out through the guide roller (6) and attached to the first composite steel strip that has been spirally rolled, and the joint between the first composite steel strip and the lower steel strip (2) is welded.

13. The continuous production equipment for composite structure spiral welded steel pipe according to claim 8, characterized in that: The production equipment includes a rotating device, the first composite steel strip is individually rolled into a tube blank, the tube blank is placed on the rotating device, and then the lower steel strip (2) is attached to the outside of the tube blank, and the welding mechanism welds the weld between the tube blank, the first composite steel strip and the lower steel strip (2).

14. The continuous production equipment for composite structure spiral welded steel pipe according to claim 9, characterized in that: The guide roller (501) is composed of a plurality of rollers with adjustable angles, the angles of the rollers matching the forward direction of the first composite steel strip, the upper steel strip being closely attached to the outer wall of the rollers, the rollers being arranged at intervals, and the gaps at the intervals being used for passing and clamping the guide vertical steel strip (3).

15. The continuous production equipment for composite structure spiral welded steel pipe according to claim 9, characterized in that: The rolling roller (503) is composed of a plurality of rollers with adjustable angles, the angles of the rollers matching the forward direction of the first composite steel strip, the upper steel strip being close to the outer wall of the rollers, the rollers being arranged at intervals, the gaps at the intervals being used to pass and clamp the guide vertical steel strip (3) and assist in rolling the vertical steel strip.

16. The continuous production equipment for composite structure spiral welded steel pipe according to claim 8, characterized in that: The continuous production equipment also includes a clamping guide device (7) for stabilizing the vertical steel strip (3), one or more of which are arranged in the circumferential direction of the spiral coil of the first composite steel strip.

17. The continuous production equipment for composite structure spiral welded steel pipe according to claim 16, characterized in that: The clamping guide device (7) comprises a guide shaft (701), wherein the guide shaft (701) is provided with a clamping guide wheel (703) corresponding to the vertical steel strip (3) on the first composite steel strip through a guide bearing (702), and a positioning spacer (705) is set between adjacent clamping guide wheels (703). A clamping groove (704) for the vertical steel strip (3) to be embedded is provided on the outer periphery of the clamping guide wheel (703), and the angle of the clamping guide device (7) matches the angle of the first composite steel strip.

18. The continuous production equipment for composite structure spiral welded steel pipe according to claim 16, characterized in that: The clamping guide device (7) is composed of a plurality of rollers with adjustable angles, the angles of the rollers matching the forward direction of the first composite steel strip, the rollers being arranged at intervals, and the gaps at the intervals being used to clamp and guide the vertical steel strip (3).

19. The continuous production equipment for composite structure spiral welded steel pipe according to claim 8, characterized in that: A micro-convex structure is provided on the shaft roller of the delivery mechanism (4), and the position of the micro-convex structure is aligned with the upper steel strip (1) at the top position of the upper vertical steel strip (3) of the first composite steel strip.

20. The continuous production equipment for composite structure spiral welded steel pipe according to claim 8, characterized in that: After the combined structure spiral welded steel pipe is formed, the spiral weld seam of the upper steel strip (1) and the spiral weld seam of the lower steel strip (2) are staggered.

21. The continuous production equipment for composite structure spiral welded steel pipe according to claim 8, characterized in that: The width of the lower steel strip (2) matches the size of the first composite steel strip.

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