Helical corrugated pipe

Abstract

The utility model relates to the technical field of corrugated pipes, and discloses a spiral corrugated pipe which comprises an inner pipe wall, a steel reinforcement body and an outer pipe wall. The inner pipe wall is formed by spirally winding an inner plastic sheet and mutually melting and lapping adjacent edges; the inner pipe wall is sleeved with the steel reinforcement body, the steel reinforcement body and the inner pipe wall are fused and bonded, the steel reinforcement body is formed by spirally winding a steel-plastic composite strip at intervals, the steel-plastic composite strip is provided with at least two wave-shaped protrusions at intervals in the width direction of the steel-plastic composite strip, every two adjacent wave-shaped protrusions are connected through a straight section, and the edge lap joint position of the inner plastic sheet corresponds to the straight section; the outer pipe wall is formed by spirally winding an outer plastic sheet, fusing and bonding the outer plastic sheet on the outer surface of the steel reinforcement body and fusing and overlapping adjacent edges. According to the spiral corrugated pipe provided by the utility model, the edge overlapping part of the inner plastic sheet is arranged corresponding to the straight section, so that the stress at the overlapping part of the inner plastic sheet is borne by the steel-plastic reinforcing body, and the strength of the inner pipe wall is improved, so that the spiral corrugated pipe is not easy to tear and damage due to factors such as foundation settlement and axial tension.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of bellows, in particular to a spiral bellows. BACKGROUND

[0002] The existing spiral buried pipe is usually composed of a plastic inner layer, a metal reinforcing layer and a plastic outer layer. The plastic inner layer is formed by overlapping the spiral wound plastic strips, the metal reinforcing layer is a steel strip spirally laid on the outer surface of the plastic inner layer at the same pitch, and the outer layer of the pipe is a plastic outer sheet laid on the outer surface of the single wave steel strip at the same pitch.

[0003] The existing structure uses single wave steel strip to lay at intervals as the reinforcing structure, and the two wave feet of the single wave steel strip and the plastic strips of the inner layer are bonded to combine the metal reinforcing layer and the plastic inner layer. In practical application, the bonding area of the metal reinforcing layer and the plastic inner layer is small, and the overlapping part of the inner plastic sheet is easily torn and damaged due to factors such as foundation settlement and axial tension. SUMMARY

[0004] The utility model aims at overcoming the technical problem that the overlapping part of the inner plastic sheet of the existing spiral bellows is easily torn and damaged due to factors such as foundation settlement and axial tension, and provides a spiral bellows, the bonding between the inner pipe wall and the steel-plastic composite pipe wall of the spiral bellows is firm, and the spiral bellows is not easily torn and damaged due to factors such as foundation settlement and axial tension.

[0005] In order to achieve the above-mentioned purpose, the utility model provides a spiral bellows, which comprises:

[0006] An inner pipe wall formed by spirally winding an inner plastic sheet and overlapping the adjacent edges;

[0007] A steel reinforcing body sleeved on the outer surface of the inner pipe wall and at least partially bonded to the inner pipe wall, the steel reinforcing body is spirally and intervally wound by a steel-plastic composite strip, the steel-plastic composite strip is provided with at least two wave-shaped protrusions at intervals in the width direction, and the adjacent two wave-shaped protrusions are connected by a flat section, and the edge overlapping part of the inner plastic sheet is provided corresponding to the flat section; and

[0008] An outer pipe wall formed by spirally winding an outer plastic sheet, bonding the outer surface of the steel reinforcing body and overlapping the adjacent edges.

[0009] Preferably, the steel-plastic composite strip comprises:

[0010] A steel sheet in the form of a strip, which comprises at least two convex parts corresponding to the wave-shaped protrusions, and the adjacent two convex parts are connected by a straight plate part; and

[0011] An adhesive layer is coated on the inner and outer surfaces of the steel strip for bonding the steel strip, the outer plastic sheet and the inner plastic sheet.

[0012] Preferably, the steel strip is formed with a folded portion parallel to the axial direction of the spiral corrugated pipe at both edges in the width direction of the steel strip.

[0013] Preferably, the straight plate portion is provided with a plurality of through holes, and part of the adhesive layer is filled in the through holes.

[0014] Preferably, the straight plate portion is provided with one or more rows of through holes in the width direction of the straight plate portion, and the distance between two adjacent through holes in each row is the same.

[0015] Preferably, part of the outer plastic sheet extends into the through holes, and the adhesive layer in the through holes and the part of the outer plastic sheet together form a plurality of connecting portions, and the plurality of connecting portions are respectively fused and bonded to the inner pipe wall.

[0016] Preferably, the diameter d of the through hole satisfies 3mm≤d≤20mm.

[0017] Preferably, the distance L between two adjacent through holes in the length direction of the steel strip satisfies 10mm≤L≤100mm.

[0018] Preferably, the spiral angle of the inner plastic sheet is equal to the spiral angle of the steel-plastic composite strip.

[0019] Preferably, the pitch of the inner plastic sheet is equal to the pitch of the steel-plastic composite strip.

[0020] Preferably, the middle part of the outer plastic sheet in the width direction of the outer plastic sheet is arranged according to the shape of the steel-plastic composite strip, and is bonded to the side of the steel-plastic composite strip away from the inner pipe wall, and the two adjacent edges of the outer plastic sheet are fused and overlapped with each other.

[0021] Preferably, the position where the two adjacent edges of the outer plastic sheet are fused and overlapped with each other is arranged at the position of the valley of the steel-plastic composite strip.

[0022] According to the above technical solution, the spiral corrugated pipe provided by the utility model realizes the support of the inner pipe wall. The steel-plastic composite strip is provided with at least two wave-shaped protrusions in the width direction, and the wave-shaped protrusions increase the strength of the spiral corrugated pipe. The two adjacent wave-shaped protrusions are connected by a flat section, and the edge overlap position of the inner plastic sheet is arranged according to the flat section, so that the stress of the overlap position of the inner plastic sheet is borne by the steel-plastic reinforcing body, and the strength of the inner pipe wall is improved. Therefore, the combination between the layers of the spiral corrugated pipe is more stable, and the spiral corrugated pipe is not easy to be torn and damaged due to factors such as foundation settlement and axial tension. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a three-dimensional structure schematic view of a spiral corrugated pipe provided by the utility model;

[0024] Figure 2 is Figure 1 the partial enlarged view of the I part of the spiral corrugated pipe shown in the figure;

[0025] Figure 3 is a cross-sectional structure schematic view of a spiral corrugated pipe provided by the utility model;

[0026] Figure 4 is a cross-sectional structure schematic view of another spiral corrugated pipe provided by the utility model;

[0027] Figure 5 is a three-dimensional structure schematic view of a strip-shaped steel sheet provided by the utility model;

[0028] Figure 6 is a cross-sectional structure schematic view of a steel-plastic composite strip provided by the utility model;

[0029] Figure 7 is a partial enlarged view of the first strip-shaped steel sheet provided by the utility model;

[0030] Figure 8 is Figure 7 the cross-sectional structure schematic view of the strip-shaped steel sheet along the A-A line shown in the figure;

[0031] Figure 9 is a partial enlarged view of the second strip-shaped steel sheet provided by the utility model;

[0032] Figure 10 is Figure 9 the cross-sectional structure schematic view of the strip-shaped steel sheet along the B-B line shown in the figure;

[0033] Figure 11 is a partial enlarged view of the third strip-shaped steel sheet provided by the utility model;

[0034] Figure 12 is Figure 11 the cross-sectional structure schematic view of the strip-shaped steel sheet along the C-C line shown in the figure;

[0035] Figure 13 is a partial enlarged view of the fourth strip-shaped steel sheet provided by the utility model;

[0036] Figure 14 is Figure 13 the cross-sectional structure schematic view of the strip-shaped steel sheet along the D-D line shown in the figure.

[0037] Explanation of reference signs

[0038] 1-spiral corrugated pipe; 10-inner pipe wall; 20-steel reinforcing body; 30-outer pipe wall;

[0039] 100 - inner plastic sheet; 200 - steel-plastic composite strip; 300 - outer plastic sheet;

[0040] 201 - protrusion; 202 - flat section;

[0041] 210 - strip-shaped steel sheet; 220 - adhesive layer; 310 - connecting portion;

[0042] 211 - protruding portion; 212 - straight plate portion; 213 - folded portion; 212a - through hole. DETAILED DESCRIPTION

[0043] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely intended to illustrate and explain the present application, and are not intended to limit the present application.

[0044] It should be noted that, in the description of the present application, unless otherwise specified, the meaning of "a plurality of" is greater than or equal to two; the terms "upper", "lower", "left", "right", "inner", "outer" and the like indicate the orientation or positional relationship only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0045] In addition, the "first", "second" and similar words used in the present application do not represent any order, quantity or importance, but are only used to distinguish different parts. "Vertical" is not strictly vertical, but within the allowable error range. "Parallel" is not strictly parallel, but within the allowable error range. "Include" or "contain" and similar words mean that the elements before the word cover the elements listed after the word, and do not exclude the possibility of also covering other elements.

[0046] Please refer to Figure 1 , Figure 2 , Figure 3 and Figure 4 , Figure 1 is a three-dimensional structural schematic view of a spiral corrugated pipe provided by the present application; Figure 2 is a partial enlarged view of the I part of the spiral corrugated pipe shown in Figure 1 ;

[0047] Figure 3 is a cross-sectional structural schematic view of a spiral corrugated pipe provided by the present application; Figure 4Is another spiral corrugated pipe cross section structure schematic diagram provided by the utility model. The utility model provides a spiral corrugated pipe 1, spiral corrugated pipe 1 includes inner tube wall 10, steel reinforcing body 20 and outer tube wall 30, wherein, inner tube wall 10 is formed by inner plastic sheet 100 spiral winding, and adjacent edge mutually fusing lap joint, steel reinforcing body 20 is set on the outer of inner tube wall 10 and at least partially fusing adhesion with inner tube wall 10, steel reinforcing body 20 is formed by steel plastic composite strip 200 spiral interval winding, steel plastic composite strip 200 is provided with at least two wave-shaped protrusions 201 in its width direction interval, and adjacent two wave-shaped protrusions 201 are connected by straight section 202, and the edge lap joint of inner plastic sheet 100 is correspondingly provided with straight section 202, outer tube wall 30 is formed by outer plastic sheet 300 spiral winding, fusing adhesion on the outer surface of steel reinforcing body 20 and adjacent edge mutually fusing lap joint.

[0048] Need to be explained, the spiral corrugated pipe 1 provided by the utility model can but is not limited to be applied in water supply and drainage buried pipeline, cable line protection, coal mining gas transportation and other agricultural, chemical, traffic municipal field fluid transportation and line protection. The above is the example of the application scene of the spiral corrugated pipe 1 provided by the utility model, and should not be understood as the limitation of the application scene of the spiral corrugated pipe 1 provided by the utility model.

[0049] It can be understood that the spiral corrugated pipe 1 provided by the utility model is a kind of steel plastic composite pipe. The external material of the spiral corrugated pipe 1 is plastic, and the inside is wrapped with supporting steel belt. Among them, the plastic in the spiral corrugated pipe 1 can be but not limited to polyethylene, high-density polyethylene, polyvinyl chloride, polypropylene and the like. The external plastic material can make the spiral corrugated pipe 1 have the advantages of smooth, light weight, corrosion resistance, and the internal steel belt can increase the strength of the spiral corrugated pipe 1.

[0050] It can be understood that the spiral corrugated pipe 1 provided by the utility model is also a kind of spiral winding pipe. The spiral corrugated pipe 1 is formed by spiral winding, fusing lap joint of the composite material of multilayer belt. Specifically, spiral corrugated pipe 1 is formed by spiral winding of inner plastic sheet 100, steel plastic composite strip 200 and outer plastic sheet 300 three-layer belt-shaped section material / material. Among them, the steel plastic composite strip is profiled by rolling. Among them, the inner plastic sheet 100 and the outer plastic sheet 300 wrap the steel plastic composite strip 200, so that the spiral corrugated pipe 1 has the characteristics of smooth, corrosion resistance, wear resistance. The steel plastic composite strip 200 is arranged to strengthen the external pressure capacity (ring stiffness) of the spiral corrugated pipe 1.

[0051] In some preferred embodiments, the spiral corrugated pipe 1 is coated with a polymer, resin or other adhesive at the joint of the fusion lap and at the joint between the inner pipe wall 10 and the steel-plastic composite pipe wall to make the joint more tightly bonded. More preferably, after the inner plastic sheet 100 is lapped, the wall thickness of the inner pipe wall 10 is uniform and the inner wall surface of the inner pipe wall 10 is relatively smooth, so that the spiral corrugated pipe 1 has a better conveying capacity.

[0052] In order to more clearly illustrate the beneficial effects of the technical scheme of the present application, the related art is introduced. Generally, the steel-plastic composite strip is provided with a wave-shaped protrusion at the center position in the width direction thereof. Two wave legs adjacent to the wave-shaped protrusion are lapped to form the steel-plastic composite pipe wall; the wave-shaped protrusion forms the corrugated structure of the spiral corrugated pipe on the outer surface of the steel-plastic composite pipe wall, thereby playing a role in increasing the strength of the spiral corrugated pipe. The lapped portion of the inner plastic sheet is provided on the inner side of the wave-shaped protrusion, as disclosed in the Chinese patent for invention with the authorization announcement No. CN1276203C. However, when the above corrugated pipe is affected by factors such as foundation settlement and axial tension in its working environment, the two lapped legs of the lapped portion of the inner plastic sheet are easily torn and damaged due to the action of force in the opposite direction along the axial direction, since they are not connected to the outer steel-plastic composite pipe wall.

[0053] In view of the above technical problems, the Chinese patent for invention with the authorization announcement No. CN200943776Y proposes a metal-reinforced spiral corrugated pipe with a reinforced pipe wall structure, in which the inner plastic sheet is lapped on the inner side of the lapped portion of the outer steel-plastic composite pipe wall. Although this improves the problem of the lapped portion of the original inner plastic sheet being easily torn by force, this structure simultaneously laps the lapped legs of two inner plastic sheets and the lapped legs of two steel-plastic composite strips at the wave leg of the steel-plastic composite pipe wall, i.e. four layers of materials. This makes the thickness of the corrugated pipe uneven, the inner wall surface uneven, and weak points exist at the transition between the wave-shaped protrusion and the wave leg, which are easily torn and damaged by pressure.

[0054] Based on the above problems, the spiral corrugated pipe 1 provided by the present application is provided with at least two wave-shaped protrusions 201 spaced apart in the width direction of the steel-plastic composite strip 200, and the lapped portion of the edge of the inner plastic sheet 100 is provided corresponding to the flat section 202, thereby increasing the bonding area of the inner pipe wall 10 and the steel-plastic composite pipe wall, so that the stress on the lapped portion of the inner plastic sheet 100 is borne by the steel-plastic reinforcement, and the strength of the inner pipe wall 10 is improved; the inner pipe wall 10 and the steel-plastic composite pipe wall are firmly bonded, and are not easily torn and damaged by factors such as foundation settlement and axial tension. The thickness of the inner plastic sheet 100 after lapping is uniform and the inner wall is smooth, and there are no weak points in strength.

[0055] Meanwhile, the spiral corrugated pipe 1 provided by the utility model is provided with two or more wave-shaped protrusions 201, so that the strength of the spiral corrugated pipe 1 is higher; accordingly, the spiral corrugated pipe 1 provided by the utility model has a wave height of the wave-shaped protrusion 201 which is lower than that of a traditional spiral corrugated pipe 1 with the same strength, a wall thickness of the corrugated pipe which is thinner, and a weight which is 20% or more lighter than that of the traditional spiral corrugated pipe 1, so that the utility model is more convenient for construction.

[0056] The wave-shaped protrusion 201 can be in the shape shown in the wave-shaped protrusion in the drawings, but is not limited to a square wave protrusion, a circular wave protrusion, a triangular wave protrusion, a trapezoidal wave protrusion, an omega wave protrusion, a semicircular wave protrusion, a wave protrusion 1, etc. Figures 1-4 The steel-plastic composite strip 200 can include two wave-shaped protrusions 201 and one flat section 202 as shown in the drawings, but is not limited to including three wave-shaped protrusions 201 and two flat sections 202, four or more wave-shaped protrusions 201 and three or more flat sections 202, etc. Figures 1-4

[0057] Please refer to Figure 3 and Figure 4 , and refer to Figure 5 and Figure 6 , Figure 5 is a schematic diagram of a three-dimensional structure of a strip-shaped steel sheet provided by the utility model; Figure 6 is a schematic diagram of a cross-sectional structure of a steel-plastic composite strip provided by the utility model. In some preferred embodiments, the steel-plastic composite strip 200 includes a strip-shaped steel sheet 210 and an adhesive layer 220. The strip-shaped steel sheet 210 includes at least two protruding portions 211 corresponding to the wave-shaped protrusions 201, and two adjacent protruding portions 211 are connected by a straight plate portion 212. The adhesive layer 220 is coated on the inner and outer surfaces of the strip-shaped steel sheet 210, and is used to bond the strip-shaped steel sheet 210, the outer plastic sheet 300 and the inner plastic sheet 100.

[0058] It can be understood that the protruding portion 211 of the strip-shaped steel sheet 210 corresponds to the wave-shaped protrusion 201 of the steel-plastic composite strip 200, and the straight plate portion 212 of the strip-shaped steel sheet 210 corresponds to the flat portion of the steel-plastic composite strip 200. The outer plastic sheet 300 has an outer plastic sheet main portion in the middle portion in the width direction, and the outer plastic sheet main portion is arranged to adhere to the outer surface of the strip-shaped steel sheet 210. Preferably, the thickness of the outer plastic sheet main portion is uniform.

[0059] ​It can be understood that the inner surface of the straight plate part 212 is melt-joined with the overlapping part of the inner plastic sheet 100, and the inner surface of the convex part 211 is spaced apart from the inner plastic sheet part of the inner plastic sheet 100, thereby forming a cavity. The two edges of the outer plastic sheet 300 are arranged to overlap with each other, thereby realizing melt-joining of the steel-plastic composite strip 200. Preferably, the overlapping part of the outer plastic sheet 300 is uniform in thickness after overlapping, and is further melt-joined with the inner plastic sheet part at the center position of the inner plastic sheet 100 on the side of the inner pipe wall 10.

[0060] It can be understood that the spiral corrugated pipe 1 can be applied to work under different temperature and pressure conditions, and the temperature and pressure of the working environment change greatly. When the temperature of the working environment of the spiral corrugated pipe 1 changes, the inner plastic sheet 100, the strip-shaped steel sheet 210 and the outer plastic sheet 300 will shrink or expand with the change of temperature. Due to the material difference between the inner plastic sheet 100, the outer plastic sheet 300 and the strip-shaped steel sheet 210, the shrinkage rate or expansion rate of the materials is different when the same temperature change is applied; this will cause the adhesion between the inner plastic sheet 100 and the strip-shaped steel sheet 210, and the adhesion between the strip-shaped steel sheet 210 and the outer plastic sheet 300 to fall off when the temperature of the working environment of the spiral corrugated pipe 1 changes.

[0061] Based on the above problems, in some preferred embodiments, the inner surface of the strip-shaped steel sheet 210 is coated with an adhesion layer 220, which can provide a buffer for the shrinkage or expansion of the strip-shaped steel sheet 210 and the inner plastic sheet 100, thereby strengthening the adhesion between the strip-shaped steel sheet 210 and the inner plastic sheet 100, and avoiding the adhesion between the strip-shaped steel sheet 210 and the inner plastic sheet 100 from falling off due to the different shrinkage rates or expansion rates of the materials. The material of the adhesion layer 220 can be, but is not limited to, a polymer adhesion material, a resin adhesion material and the like.

[0062] The adhesion layer 220 is also coated on the outer surface of the strip-shaped steel sheet 210, which provides a buffer for the shrinkage or expansion of the strip-shaped steel sheet 210 and the outer plastic sheet 300, thereby strengthening the adhesion between the strip-shaped steel sheet 210 and the outer plastic sheet 300, and avoiding the adhesion between the strip-shaped steel sheet 210 and the outer plastic sheet 300 from falling off due to the different shrinkage rates or expansion rates of the materials. In some preferred embodiments, the adhesion layer 220 is also coated on the edge of the strip-shaped steel sheet 210, thereby enhancing the buffer effect of the adhesion layer 220 on the shrinkage or expansion between the strip-shaped steel sheet 210 and the outer plastic sheet 300.

[0063] Please refer toFigures 7 to 14 In some preferred embodiments, the strip steel sheet 210 is formed with a fold 213 parallel to the axial direction of the spiral bellows 1 at both edges in the width direction thereof.

[0064] It can be understood that the strip steel sheet 210 provided by the utility model is provided with a straight plate portion 212 between every two adjacent convex portions 211, that is, the strip steel sheet 210 is provided with a convex portion 211 adjacent to both edges thereof. One wave leg of the convex portion 211 adjacent to the edge of the strip steel sheet 210 is connected with the straight plate portion 212, and the other wave leg is wrapped in the outer plastic sheet 300 and the inner plastic sheet 100. When the two edges of the strip steel sheet 210 do not contain the fold 213 extending in the opposite direction of the axial direction of the spiral bellows 1, the bonding area of the edge of the strip steel sheet 210 with the outer plastic sheet 300 and the inner plastic sheet 100 is small, which easily leads to the bonding of the edge of the strip steel sheet 210 being not firm and stress concentration.

[0065] The strip steel sheet 210 provided by the embodiment is formed with a fold 213 parallel to the axial direction of the spiral bellows 1 at both edges, the fold 213 significantly increases the bonding area of the strip steel sheet 210 and the inner plastic sheet 100, effectively improves the bonding strength of the strip steel sheet 210 and the inner plastic sheet 100, and the fold 213 also significantly increases the wrapping volume of the outer plastic sheet 300 to the strip steel sheet 210, effectively improves the joint strength of the strip steel sheet 210 and the outer plastic sheet 300.

[0066] Further, the strip steel sheet 210 is arranged to play a role in supporting and strengthening the spiral bellows 1. When the spiral bellows 1 is subjected to radial pressure, the convex portion 211 of the strip steel sheet 210 is subjected to radial pressure, and part of the radial pressure is decomposed and converted into axial tension through the shape of the strip steel sheet 210, thereby achieving the supporting and strengthening of the spiral bellows 1.

[0067] When the two edges of the strip steel sheet 210 do not contain the fold 213 parallel to the axial direction of the spiral bellows 1, the contact area of the edge of the strip steel sheet 210 with the inner tube wall 10 is small, which easily leads to the corresponding inner tube wall 10 at the edge of the strip steel sheet 210 being subjected to excessive stress. The strip steel sheet 210 provided by the embodiment is formed with a fold 213 parallel to the axial direction of the spiral bellows 1 at both edges, which can effectively increase the contact area of the edge of the strip steel sheet 210 with the inner tube wall 10, reduce the stress of the inner tube wall 10, and avoid the deformation and damage of the inner tube wall 10.

[0068] Please refer to againFigures 7 to 14 In some preferred embodiments, the straight plate portion 212 is provided with a plurality of through holes 212a, and part of the adhesive layer 220 is filled in the through holes 212a.

[0069] It can be understood that the inner plastic sheet 100 and the strip steel sheet 210 are melt-bonded, the outer plastic sheet 300 and the strip steel sheet 210 are melt-bonded, and the edge lap of the outer plastic sheet 300 and the inner plastic sheet 100 are melt-bonded, thereby realizing the composite bonding of the multi-layer material of the spiral corrugated pipe 1. However, the bonding part between the inner plastic sheet 100 and the outer plastic sheet 300 is only the spiral winding edge lap, and the connection area between the inner plastic sheet 100 and the outer plastic sheet 300 wrapping the strip steel sheet 210 is too small, which is easy to cause the multi-layer material to be not firmly connected.

[0070] The straight plate portion 212 provided by the embodiment is provided with a plurality of through holes 212a, and part of the adhesive layer 220 is filled in the through holes 212a, so that the inner plastic sheet 100 and the outer plastic sheet 300 are also connected through the adhesive layer 220 in the through holes 212a, which significantly increases the bonding area of the inner plastic sheet 100 and the outer plastic sheet 300 in the middle part of the strip steel sheet 210. Therefore, the connection between the multi-layer composite materials is more firm, and is not easy to be separated and fallen off due to the temperature and pressure of the spiral corrugated pipe 1.

[0071] Please refer again to Figures 7 to 14 In some preferred embodiments, the straight plate portion 212 is provided with one or more rows of through holes 212a in the width direction thereof, and the distance between two adjacent through holes 212a in each row is the same.

[0072] It can be understood that the plurality of through holes 212a are uniformly and dispersedly arranged in the length direction of the strip steel sheet 210, so that the inner plastic sheet 100 and the outer plastic sheet 300 can be stably bonded at each position in the length direction thereof, thereby making the connection of the three-layer composite material of the spiral corrugated pipe 1 more firm.

[0073] It can be understood that the straight plate portion 212 can be provided with one row (see Figure 7 , Figure 8 ), two rows (see Figures 9 to 14 ), or three or more rows of through holes 212a; the distance between two adjacent through holes 212a in each row is the same. Preferably, the row distance of the through holes 212a in different rows is also the same, thereby making the stress of the bonding points of the inner plastic sheet 100 and the outer plastic sheet 300 more uniform. It can be understood that the plurality of through holes 212a with equal row distance can be arranged side by side (see Figure 9 , Figure 10 ,Figure 13 and Figure 14 ), and can be staggered (see Figure 11 and Figure 12 ).

[0074] Preferably, each turn of the spirally wound strip steel sheet 210 is provided with at least one through hole 212a, so that the three-layer composite material of the spiral corrugated pipe 1 can be stably bonded in the axial direction thereof; more preferably, each turn of the spirally wound strip steel sheet 210 is provided with at least two through holes 212a, so that the three-layer composite material of the spiral corrugated pipe 1 can be stably bonded in the axial direction thereof and in the circumferential direction thereof.

[0075] In some specific embodiments, see Figure 7 and Figure 8 , Figure 7 is a partial enlarged view of a first strip steel sheet provided by the utility model; Figure 8 is Figure 7 a cross-sectional structure schematic view of the strip steel sheet along the line. The strip steel sheet 210 provided by the embodiment includes two convex portions 211 and one straight plate portion 212. Specifically, the strip steel sheet 210 sequentially includes a folded portion 213, a convex portion 211, a straight plate portion 212, a convex portion 211 and a folded portion 213 along the width direction thereof. The straight plate portion 212 has a row of through holes 212a, and the distance between adjacent two through holes 212a is the same.

[0076] In some specific embodiments, see Figure 9 and Figure 10 , Figure 9 is a partial enlarged view of a second strip steel sheet provided by the utility model; Figure 10 is Figure 9 a cross-sectional structure schematic view of the strip steel sheet along the line B-B. The strip steel sheet 210 provided by the embodiment includes two convex portions 211 and one straight plate portion 212. Specifically, the strip steel sheet 210 sequentially includes a folded portion 213, a convex portion 211, a straight plate portion 212, a convex portion 211 and a folded portion 213 along the width direction thereof. The straight plate portion 212 has two rows of through holes 212a arranged side by side in the width direction thereof.

[0077] In some specific embodiments, see Figure 11 and Figure 12 , Figure 11 is a partial enlarged view of a third strip steel sheet provided by the utility model; Figure 12 is Figure 11The cross-sectional structure of the strip steel sheet along the line C-C is shown in the schematic view. The strip steel sheet 210 provided by the embodiment includes two convex portions 211 and one straight plate portion 212, and specifically, the strip steel sheet 210 includes, along the width direction thereof, a folding portion 213, a convex portion 211, a straight plate portion 212, a convex portion 211 and a folding portion 213 in sequence. The straight plate portion 212 is provided with two rows of through holes 212a arranged in the width direction thereof.

[0078] In some specific embodiments, referring to Figure 13 and Figure 14 , Figure 13 is a partial enlarged view of a fourth strip steel sheet provided by the utility model; Figure 14 is Figure 13 The cross-sectional structure of the strip steel sheet along the line D-D is shown in the schematic view. The strip steel sheet 210 provided by the embodiment includes three convex portions 211 and two straight plate portions 212, and specifically, the strip steel sheet 210 includes, along the width direction thereof, a folding portion 213, a convex portion 211, a straight plate portion 212, a convex portion 211, a straight plate portion 212, a convex portion 211 and a folding portion 213 in sequence. Each of the straight plate portions 212 is provided with two rows of through holes 212a arranged in parallel in the width direction thereof.

[0079] Please refer to Figure 3 and Figure 4 again. In some preferred embodiments, the outer plastic sheet 300 is partially inserted into the through holes 212a, and the adhesive layer 220 located in the through holes 212a and the outer plastic sheet 300 jointly form a plurality of connecting portions 310, and the plurality of connecting portions 310 are respectively fused and bonded to the inner pipe wall 10.

[0080] It can be understood that, in the above embodiment, the adhesive layer 220 located in the through holes 212a and the outer plastic sheet 300 partially inserted into the through holes 212a jointly form the connecting portions 310. It can be understood that the inner plastic sheet 100 and the outer plastic sheet 300 are made of the same or similar material, i.e. the same or similar kind of plastic. In the above embodiment, the plurality of connecting portions 310 are respectively inserted into the plurality of through holes 212a and fused and bonded to the inner pipe wall 10, which makes the inner plastic sheet 100 and the outer plastic sheet 300 riveted and connected as a whole through the connecting portions 310 of the outer plastic sheet 300. Thus, the bonding strength of the inner pipe wall 10 and the steel-plastic composite pipe wall is further increased.

[0081] The manufacturing method of the spiral corrugated pipe 1 provided by the above embodiment can be divided into three steps: punching of straight steel strip, coating of adhesive layer 220 after punching, and pipe manufacturing. In the first step, the straight steel strip is unwound, the central part of the unwound steel strip is punched to form through holes 212a in the steel strip, and finally the punched steel strip with through holes 212a is wound.

[0082] In the second step, the steel strip with through holes 212a is unwound, the unwound steel strip with holes is heated, then the molten adhesive layer 220 is extruded into the mold using an extruder, the heated unwound steel strip with holes is passed through the mold for adhesive layer 220 compounding, then the compounded steel strip-adhesive layer 220 strip is cooled and pulled, and finally the rubber-coated steel strip coated with adhesive layer 220 is wound.

[0083] In the third step, the molten inner plastic sheet 100 is extruded using an extruder and is overlapped to form an inner pipe wall 10, the outer surface of the inner pipe wall 10 is heated, then the prepared rubber-coated steel strip coated with adhesive layer 220 is spirally and intervaliy laid on the outer surface of the inner pipe wall 10, the molten outer plastic sheet 300 is extruded using an extruder and is spirally and intervaliy laid on the outer surface of the steel strip, then part of the outer plastic sheet 300 is pressed into the through holes 212a of the steel strip using a pressure roller to form connecting parts 310, the connecting parts 310 and the inner plastic sheet 100 are fused and bonded under the action of heat to become an integral whole, and finally the spiral corrugated pipe 1 is cooled, cut and stored to complete the manufacturing of the spiral corrugated pipe 1.

[0084] Please refer again to Figures 7 to 14 In some preferred embodiments, the hole diameter of the through hole 212a satisfies 3mm≤d≤20mm. In some preferred embodiments, the distance between two adjacent through holes 212a satisfies 10mm≤L≤100mm.

[0085] It can be understood that if the hole diameter of the through hole 212a is set too large, the steel sheet area of the straight plate part 212 of the steel strip 210 will be too small, affecting the connection stability between the multiple convex parts 211 of the steel strip 210, thereby reducing the support strength of the steel strip 210; if the hole diameter of the through hole 212a is set too small, the adhesive area of the outer plastic sheet 300 and the inner plastic sheet 100 directly bonded through the connecting parts 310 of the outer plastic sheet 300 or indirectly bonded through the adhesive layer 220 in the through hole 212a will be too small, thereby affecting the bonding strength of the inner pipe wall 10 and the steel-plastic composite pipe wall.

[0086] The hole diameter of the through hole 212a in the above embodiment satisfies 3mm≤d≤20mm, which can make the structure of the steel strip 210 realize the support strength, the compression strength of the spiral corrugated pipe 1 and the joint strength of the inner pipe wall 10 and the steel-plastic composite pipe wall of the spiral corrugated pipe 1.

[0087] It can be understood that, if the interval between the two adjacent through holes 212a is too small, the steel sheet area of the straight plate part 212 of the steel strip 210 is too small, which affects the connection stability between the multiple convex parts 211 of the steel strip 210, thereby reducing the support strength of the steel strip 210; if the interval between the two adjacent through holes 212a is too large, the bonding area of the outer plastic sheet 300 and the inner plastic sheet 100 directly bonded through the connecting part 310 of the outer plastic sheet 300 or indirectly bonded through the bonding layer 220 in the through hole 212a is too small, thereby affecting the joint strength of the inner pipe wall 10 and the steel-plastic composite pipe wall.

[0088] The interval between the two adjacent through holes 212a in the above embodiment satisfies 10mm≤L≤100mm, which can make the structure of the steel strip 210 realize the support strength, the compression strength of the spiral corrugated pipe 1 and the joint strength of the inner pipe wall 10 and the steel-plastic composite pipe wall of the spiral corrugated pipe 1. It should be noted that the interval between the two adjacent through holes 212a in the utility model should be understood as the interval between the center positions of the two adjacent through holes 212a.

[0089] Please refer again to Figure 1 In some preferred embodiments, the spiral angle of the inner plastic sheet 100 is equal to the spiral angle of the steel-plastic composite strip 200. In some preferred embodiments, the pitch of the inner plastic sheet 100 is equal to the pitch of the steel-plastic composite strip 200.

[0090] It can be understood that, when the spiral corrugated pipe 1 is subjected to extrusion, the outer layer of the steel-plastic composite strip 200 conducts pressure to the inner layer of the inner plastic sheet 100. When the inner plastic sheet 100 and the steel-plastic composite strip 200 are arranged in a staggered manner, the stress point area of the inner plastic sheet 100 is small, and the inner pipe wall 10 of the spiral corrugated pipe 1 is easily deformed and damaged by extrusion.

[0091] In the above embodiment, the helix angles of the inner plastic sheet 100 and the steel-plastic composite strip 200 are equal, so that the inner plastic sheet 100 and the steel-plastic composite strip 200 of the spiral corrugated pipe 1 are arranged in parallel and side by side, so that when the steel-plastic composite strip 200 transmits pressure to the inner plastic sheet 100, the stress area of the inner plastic sheet 100 is larger than that of the inner plastic sheet 100 and the steel-plastic composite strip 200 arranged in staggered manner, so that the structure of the spiral corrugated pipe 1 is more stable and resistant to pressure.

[0092] It can be understood that the steel-plastic composite pipe wall is formed by winding the steel-plastic composite strip 200 for several turns, and the inner pipe wall 10 is formed by winding the inner plastic sheet 100 for several turns. When the pitches of the inner plastic sheet 100 and the steel-plastic composite strip 200 are not equal, the flat sections 202 of a part of the turns of the steel-plastic composite strip 200 will be glued at the overlapping portions with the inner plastic sheet 100, and the flat sections 202 of another part of the turns of the steel-plastic composite strip 200 will not be glued at the overlapping portions with the inner plastic sheet 100. This will make the strength of the spiral corrugated pipe 1 in the axial direction uneven, and the weak strength part is easily damaged by extrusion.

[0093] In the above embodiment, the pitches of the inner plastic sheet 100 and the steel-plastic composite strip 200 are equal, so that the number of turns of the inner plastic sheet 100 of the spiral corrugated pipe 1 is equal, and the two are arranged correspondingly, so that the spiral corrugated pipe 1 is uniformly stressed in the axial direction, and there is no weak strength point, and it is not easy to be deformed and damaged by extrusion.

[0094] Please refer again to Figure 3 and Figure 4 In some preferred embodiments, the middle part of the outer plastic sheet 300 in the width direction is arranged corresponding to the shape of the steel-plastic composite strip 200, and is adhered to the side of the steel-plastic composite strip 200 away from the inner pipe wall 10, and the two adjacent edges of the outer plastic sheet 300 are meltingly overlapped with each other.

[0095] The middle part of the outer plastic sheet 300 is adhered to the side of the steel-plastic composite strip 200 away from the inner pipe wall 10, so that the outer plastic sheet 300 and the steel-plastic composite strip 200 have a larger contact area, and the steel-plastic composite strip 200 can better support the spiral corrugated pipe 1. More preferably, the outer plastic sheet 300 is also meltingly adhered to the two edges of the steel-plastic composite strip 200, so that the outer plastic sheet 300 and the steel-plastic composite strip 200 are not easy to fall off each other due to shrinkage, expansion, extrusion deformation, etc.

[0096] The two adjacent edges of the outer plastic sheet 300 are fused and overlapped with each other, so that the outer plastic sheet 300 is spirally wound to form the outer pipe wall 30, and the inner pipe wall 10 and the outer pipe wall 30 together wrap the steel-plastic composite strip 200 to form a three-layer composite spiral corrugated pipe 1 structure.

[0097] Please refer again to Figure 3 and Figure 4 In some preferred embodiments, the fused and overlapped positions of the adjacent edges of the outer plastic sheet 300 are arranged at the spaced-apart valley positions of the adjacent steel-plastic composite strips 200.

[0098] It can be understood that, in the present embodiment, the inner surface of the overlapped position of the outer pipe wall 30 is also fused and bonded with the outer surface of the inner pipe wall 10. It can be understood that, due to the material difference between the strip-shaped steel sheet 210 and the outer plastic sheet 300, the bonding strength between the strip-shaped steel sheet 210 and the outer plastic sheet 300 is significantly lower than the bonding strength between the inner plastic sheet 100 and the outer plastic sheet 300. Meanwhile, the overlapped position of the outer pipe wall 30 is the weak point of the strength of the outer pipe wall 30, and the spiral corrugated pipe 1 provided by the above embodiment is fused and bonded between the overlapped position of the outer pipe wall 30 and the outer surface of the inner pipe wall 10, so as to increase the strength of the overlapped position of the outer pipe wall 30, and make the structure of the spiral corrugated pipe 1 more stable.

[0099] The preferred embodiments of the present application are described in detail above in combination with the drawings, but the present application is not limited thereto. It should be understood by those skilled in the art that the above examples or embodiments are only for illustration, but not for limiting the scope of the present application. It should be understood by those skilled in the art that the above examples or embodiments can be modified or some technical features can be replaced equivalently without departing from the scope and spirit of the present application. In particular, as long as there is no structural conflict, each technical feature mentioned in each example or embodiment can be combined in any way.

Claims

1. A spiral bellows (1) characterized in that, The spiral corrugated pipe (1) comprises: an inner pipe wall (10) formed by helically winding an inner plastic sheet (100) with adjacent edges mutually fused and overlapped; a steel reinforcement (20) sleeved outside the inner pipe wall (10) and at least partially fused and bonded with the inner pipe wall (10), the steel reinforcement (20) being helically and spacedly wound by a steel plastic composite strip (200) which is spacedly provided with at least two wave-shaped protrusions (201) in the width direction of the steel plastic composite strip (200), and two adjacent wave-shaped protrusions (201) are connected by a flat section (202), and the edge overlap of the inner plastic sheet (100) is provided corresponding to the flat section (202); and an outer pipe wall (30) formed by helically winding an outer plastic sheet (300) which is fused and bonded to the outer surface of the steel reinforcement (20) and adjacent edges are mutually fused and overlapped.

2. A spiral bellows (1) according to claim 1, characterized in that The steel plastic composite strip (200) comprises: a steel strip (210) comprising at least two protrusions (211) corresponding to the wave-shaped protrusions (201), and two adjacent protrusions (211) are connected by a straight plate section (212); and an adhesive layer (220) coated on the inner and outer side surfaces of the steel strip (210) for bonding the steel strip (210), the outer plastic sheet (300) and the inner plastic sheet (100).

3. A spiral bellows (1) according to claim 2, characterized in that The two edges of the steel strip (210) in the width direction are formed with folded sections (213) parallel to the axial direction of the spiral corrugated pipe (1).

4. A spiral bellows (1) according to claim 2, characterized in that The straight plate section (212) has a plurality of through holes (212a), and part of the adhesive layer (220) is filled in the through holes (212a).

5. A spiral bellows (1) according to claim 4, characterized in that The straight plate section (212) is provided with one or more rows of through holes (212a) in the width direction, and the distance between two adjacent through holes (212a) in each row is the same.

6. A spiral bellows (1) according to claim 4, characterized in that Part of the outer plastic sheet (300) extends into the through holes (212a) and the adhesive layer (220) located in the through holes (212a) together form a plurality of connecting sections (310), and the plurality of connecting sections (310) are respectively fused and bonded with the inner pipe wall (10).

7. The spiral corrugated pipe (1) according to any one of claims 4-6, wherein the aperture d of the through hole (212a) satisfies 3mm≤d≤20mm; and / or the distance L between two adjacent through holes (212a) along the length direction of the steel strip (210) satisfies 10mm≤L≤100mm.

8. The spiral corrugated pipe (1) according to any one of claims 1-6, wherein the helix angle of the inner plastic sheet (100) is equal to the helix angle of the steel plastic composite strip (200); and / or the pitch of the inner plastic sheet (100) is equal to the pitch of the steel plastic composite strip (200).

9. A spiral bellows (1) according to any one of claims 1-6, characterized in that The middle part of the outer plastic sheet (300) in the width direction corresponds to the shape of the steel-plastic composite strip (200) and is adhesively bonded to the side of the steel-plastic composite strip (200) away from the inner tube wall (10), and the two adjacent edges of the outer plastic sheet (300) are melt-lap jointed to each other.

10. A spiral bellows (1) according to claim 9, characterized in that The melt-lap jointed position of the adjacent edges of the outer plastic sheet (300) is arranged at the spaced-apart valley position of the adjacent steel-plastic composite strips (200).

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