Plastic corrugated pipe for air conditioning and / or ventilation technology

Abstract

Plastic corrugated pipe for air conditioning and / or ventilation technology, designed as a single-layer or double-layer corrugated pipe (1, 1a), which has a corrugated profile (10) that forms the outside of the corrugated pipe (1, 1a), wherein it is provided, - that the corrugated profile (10) is formed from wave crests (10b) arranged one behind the other in the direction of the axis (RA) of the corrugated pipe (1, 1a) with wave troughs (10t) arranged between immediately adjacent wave crests (10b), - that the outer circumference (Ua) of the wave profile (10) is formed by the outer circumference of the wave crests (10b) and is non-circular or round, - that the inner circumference (Ui) of the wave profile (10) is formed by the outer circumference of the wave troughs (10t) and is non-circular, characterized in that - that the inner circumference (Ui) has one or more circumferential sections (Ui2) with a strong curvature (R2) and one or more circumferential sections (Ui1) with a weak curvature (R1), wherein in at least one of the circumferential sections (Ui2) with a strong curvature (R2) the wave profile (10) has a greater wave height (H), preferably at least on average a greater wave height (H), than in at least one of the circumferential sections (Ui1) with a weak curvature (R1); and - that the shape of the outer circumference (Ua) is non-circular and elliptical, wherein, in a modification of the elliptical shape, both of the mutually opposite longitudinal sides of the outer circumference (Ua), which are assigned to the circumferential sections (Ui1, Ui1) of the inner circumference (Ui) with slight curvature (R1, R1), are flattened and parallel with a linear course at least in sections; and - that the shape of the inner circumference (Ui) is elliptical, wherein the opposing circumferential sections (Ui1, Ui1) are convex with a slight curvature (R1, R1); and - that the outer cross-section of the corrugated pipe (1, 1a) formed by the outer circumference (Ua) of the corrugated profile (10) has a cross-sectional height aligned along the minor axis (a2) of a minimum of 48.5 mm to a maximum of 52.0 mm and a cross-sectional width aligned along the major axis (a1) of a minimum of 139.7 mm to a maximum of 142.3 mm.

Description

[0001] The invention relates to plastic corrugated pipes having the features according to the preamble of patent claim 1.

[0002] The invention relates to a preferably non-circular corrugated pipe. The corrugated pipe is manufactured in a known manner using a corrugator. The corrugated pipe can be designed as a single-walled corrugated pipe or as a double-walled corrugated pipe. The double-walled corrugated pipe consists of a substantially smooth inner pipe and an outer pipe having a corrugated profile. The inner pipe is preferably designed as a smooth pipe, but can also have a slight corrugation. Pipes of this type are used, for example, as part of a room ventilation system in the construction industry, usually as ventilation pipes. Another area of ​​application for pipes of this type in the construction industry is as a pipe for guiding cables accommodated therein.

[0003] These corrugated pipes are mainly evaluated according to the following criteria: - Size of the cross-sectional area F1 enclosed by the inner skin. This should be as large as possible. In the case of designs as ventilation pipes, the flow space (air duct) enclosed by the inner skin should be as large as possible. - Suitable for installation purposes, allowing for minimal effort and non-destructive bending. The pipe should be as flexible as possible. - Resistance to external forces (e.g. pressure load) should be as high as possible.

[0004] The engineering challenge is to optimize the aforementioned, sometimes conflicting criteria by choosing a suitable geometry.

[0005] The state of the art knows a multitude of solutions, the essential distinguishing feature of which is the geometric design of the cross-sectional area (oval design, loaf shape, hourglass shape, etc.) and the characteristics of the profile parameters of the wave profile, namely the profile parameters wave width and wave height.

[0006] The invention is based on the object of creating a plastic corrugated pipe which, despite its non-circular cross-sectional shape, has the largest possible internal cross-section and at the same time has high flexibility for installation purposes and high resistance to damage during operation. Preferably, preferred designs as flow pipes should have the smallest possible flow resistance.

[0007] The invention solves the problem with the subject matter of the main claim 1. This subject matter is a plastic corrugated pipe for air conditioning and / or ventilation technology designed as a single-layer or double-layer corrugated pipe, which has a corrugated profile that forms the outside of the corrugated pipe.

[0008] Preferably, - that the corrugated profile is formed from wave crests arranged one behind the other in the direction of the axis of the corrugated pipe with wave troughs arranged between immediately adjacent wave crests, - that the outer circumference of the wave profile is formed by the outer circumference of the wave crests and is non-circular or round, - that the inner circumference of the wave profile is formed by the outer circumference of the wave troughs and is non-circular.

[0009] The solution according to the invention provides that the inner circumference has one or more circumferential sections with strong curvature and one or more circumferential sections with weak curvature, wherein in at least one of the circumferential sections with strong curvature the wave profile has a greater wave height, preferably at least on average a greater wave height, than in at least one of the circumferential sections with weak curvature.

[0010] As a result, in comparison to corrugated pipes in which the profile height H, i.e. the wave height of the corrugated profile is constant over the circumference of the corrugated profile, the area of ​​the cross-section can be significantly increased and, in designs as ventilation pipes, the flow resistance is reduced. The inventive design of the corrugated profile with a large profile height H in a circumferential section of strong curvature is significant for achieving resistance to external forces (e.g. for achieving the test force according to the standard DIN EN ISO 61386-24). In a circumferential section of slight curvature, on the other hand, the profile height H can be made smaller since this area preferably only contributes insignificantly to achieving the required test forces. As a consequence, with the inventive design, the area F of the cross-section is increased while the resistance is almost the same.

[0011] The profile geometry is preferably designed such that a smooth transition occurs between the different wave heights. This can mean that the wave height H preferably has a minimum in a central region of a circumferential section with a slight curvature, and the wave height H preferably has a maximum in a central region of a circumferential section with a strong curvature.

[0012] However, the wave profile can also be designed in such a way that the respective minimum of the profile height, preferably in the circumferential section of weak curvature, or the respective maximum of the profile height, preferably in the circumferential section of strong curvature, extends over a larger area, for example the profile height in the circumferential section of strong curvature is maximum in the entire circumferential section.

[0013] According to the invention, the shape of the outer circumference is non-circular and elliptical, wherein, in a modification of the elliptical shape, both of the mutually opposite longitudinal sides of the outer circumference, which are assigned to the circumferential sections of the inner circumference with slight curvature, are flattened and parallel with at least partially linear progression; and the shape of the inner circumference is elliptical, wherein the mutually opposite circumferential sections with slight curvature are convex, It is essential that the outer cross-section of the corrugated pipe formed by the outer circumference of the corrugated profile has a cross-sectional height aligned along the minor axis of a minimum of 48.5 mm to a maximum of 52.0 mm and a cross-sectional width aligned along the major axis of a minimum of 139.7 mm to a maximum of 142.3 mm.

[0014] Particularly preferred embodiments emerge from the features of the subclaims. With regard to the different circumferential sections, i.e. circumferential section with strong curvature and circumferential section with weak curvature, the terms strong curvature and weak curvature are primarily to be understood to mean that the curvature is stronger in the circumferential section with strong curvature than in the circumferential section with weak curvature. Strong curvature means a relatively small radius of curvature, which can be constant or varying in the respective circumferential section. Weak curvature means a relatively large radius of curvature, which can also be constant or varying over the section. Weak curvature is also to be understood as a linear course, i.e. an infinite radius of curvature, and in particular also a concave configuration.

[0015] In preferred embodiments, the inner circumference may have at least two, preferably opposite, circumferential sections with a strong curvature and at least two, preferably opposite, circumferential sections with a slight curvature. The cross-sectional shape of such tubes may be symmetrical or asymmetrical with respect to the inner circumference.

[0016] Preferred embodiments can provide that two adjacent circumferential sections of the inner circumference, one of which is designed as a circumferential section of strong curvature and the other as a circumferential section of weak curvature, continuously merge into one another with regard to the different wave height of the wave profile and / or with regard to their different curvature, preferably forming a continuous transition section.

[0017] In particularly preferred embodiments, for the design of the wave profile within the circumferential section of strong curvature, ie viewed along this circumferential section, it can be provided that within one or more, preferably each of the circumferential sections with strong curvature in the wave profile along the circumferential section, the wave height and / or the curvature of the circumferential section is constant or variable, preferably forming a preferably convex maximum or forming a plurality of maxima, preferably alternately variable.

[0018] In preferred further developments, it can be provided that the course of the varying profile height and / or curvature is continuous along the circumferential section of strong curvature.

[0019] In special embodiments, for the design of the wave profile within the circumferential section of slight curvature, ie for the design along this circumferential section, it can be provided that within one or more, preferably each of the circumferential sections with slight curvature in the wave profile along the circumferential section, the wave height and / or the curvature of the circumferential section is designed to be variable, preferably varying to form a minimum, preferably varying alternately.

[0020] In preferred further developments, it can be provided that the course of the varying wave height and / or curvature along the circumferential section of weak curvature is continuous.

[0021] As far as the design of the wave profile is concerned, particularly preferred embodiments provide that along the inner circumference in the wave profile, the profile parameters wave height and wave width vary and preferably also the wave base width and / or wave rise angle and / or pitch vary or are varied, in that in the circumferential section of strong curvature, the wave height has the value H2, the wave width has the value B2, the wave base width has the value A2 / 2, the wave rise angle has the value α2 and the pitch has the value T2, and in the circumferential section of weak curvature, the wave height has the value H1, the wave base width has the value A1 / 2, the wave rise angle has the value α1 and the pitch has the value T1, wherein the wave height and the wave width form the following relationship: - Relation 1 (wave profile variant 1): H2 > H1 and B2 = B1 or - Relation 2 (wave profile variant 2): H2 > H1 and B2 ≠ B1, preferably B2 > B1 or - Relation 3 (wave profile variant 3): H2 > H1 and B2 < B1

[0022] Preferred further training may include: Relation 1.1: that relation 1 (wave profile variant 1) applies in combination with one or more of the following relations: - A2 / 2 < A1 / 2 - α2 = α1 - T2 = T1 or Relation 1.2: that relation 2 (wave profile variant 2) in combination with one or several of the following relations apply: - A2 / 2 < A1 / 2 - α2 ≠ α1, preferably α2 < α1 - T2 = T1 or Relation 1.3: that relation 3 (wave profile variant 3) in combination with one or several of the following relations apply: - A2 / 2 = A1 / 2 - α2 ≠ α1, preferably α2 > α1 - T2 = T1

[0023] The invention is explained in more detail below with reference to drawings.

[0024] Showing: Fig. 1a-1d: Cross-section of the corrugated pipe perpendicular to the pipe axis, for four corrugated pipe designs that differ in the shape of the pipe cross-section, as follows: Fig. 1a: Cross-section of corrugated pipe design A, not according to the invention; Fig. 1b: Cross section of corrugated pipe design B, not according to the invention; Fig. 1c: Cross section of the corrugated pipe design C, according to the invention; Fig. 1d: Cross section of corrugated pipe design D, not according to the invention. Fig. 1.1x and Fig. 1.1y: Longitudinal sections of a corrugated profile variant 1 for the corrugated pipe designs of the Fig. 1a to 1d, where Fig. 1.1x a longitudinal section along the horizontal section plane XX in the Fig. 1a to 1d and Fig. 1.1y a longitudinal section along the vertical section plane YY in the Fig. 1a to 1d; Fig. 1.2x and Fig. 1.2y: Longitudinal sections of a corrugated profile variant 2 for the corrugated pipe designs of the Fig. 1a to 1d, where Fig. 1.2x a longitudinal section along the horizontal section plane XX in the Fig. 1a to 1d and Fig. 1.2y a longitudinal section along the vertical section plane YY in the Fig. 1a to 1d; Fig. 1.3x and Fig. 1.3y: Longitudinal sections of a corrugated profile variant 3 for the corrugated pipe designs of the Fig. 1a to 1d, where Fig. 1.3x a longitudinal section along the horizontal section plane XX in the Fig. 1a to 1d and Fig. 1.3y a longitudinal section along the vertical section plane YY in the Fig. 1a to 1d; Fig. 2 perspective view of a pair of mold jaws

[0025] The illustrated embodiments are plastic composite pipes designed as double-layer corrugated pipes with a corrugated outer pipe 1a and a largely smooth inner pipe 1i, which is arranged coaxially with the axis RA of the corrugated pipe in the corrugated outer pipe 1a and is preferably welded to the corrugation troughs of the outer pipe 1a. The corrugated outer pipe 1a and the smooth inner pipe 1i are shown in the longitudinal section views. Fig. 1.1x and y to Fig. 1.3x and y visible on average.

[0026] In the Fig. 1a to 1d show four different corrugated pipe designs A, B, C and D, whereby only the corrugated pipe design C is shown in Fig. 1c is in accordance with the invention. The designs differ in the shape of the corrugated pipe cross-section, ie, in the shape of the inner circumference Ui, which is formed by the circumferential contour of the inner pipe 1i.

[0027] In corresponding designs of single-walled corrugated pipes, the inner circumference Ui is formed by the circumferential contour formed by the corrugation troughs.

[0028] The inner circumference Ui is non-circular in corrugated pipe designs A, B, C, and D, as can be seen from the cross-sectional views. The outer circumference Ua, formed by the contour of the outer circumference of the corrugation crests, is also non-circular in designs A, B, C, and D, as can be seen from the cross-sectional views, but its shape differs slightly from that of the inner circumference Ui in some circumferential sections.

[0029] For corrugated pipe version A in Fig. 1a, the shape of the inner circumference Ui is elliptical with a major horizontal axis a1 and a minor vertical axis a2. The circumferential contour is symmetrical about the horizontal central axis and the vertical central axis. The circumference Ui has two opposite circumferential sections Ui2 with strong curvature and a small radius of curvature R2, and two opposite circumferential sections Ui1 with weak curvature and a large radius of curvature R1. The circumferential sections adjoin one another tangentially, forming the symmetrical elliptical shape of the inner circumference Ui.

[0030] The corrugated pipe version B in Fig. 1b is also symmetrical. However, unlike design A, the slightly curved circumferential sections Ui1 in design B are not convex, but concave. This cross-sectional shape is referred to in practice as an hourglass shape.

[0031] The corrugated pipe version C in Fig. 1c differs from the corrugated pipe designs A and B in that in the corrugated pipe design C the opposite circumferential sections Ua1 of the outer circumference Ua are each formed linearly parallel to each other in order to form flat support surfaces on these opposite sides.

[0032] The corrugated pipe version D in Fig. 1d is referred to in practice as a bread loaf shape. The cross-sectional shape is asymmetrical. The opposing sections Ui1 are designed differently in this case. The lower circumferential section Ui1 is very slightly curved. The associated lower circumferential section Ua1 formed on the outer circumference Ua is linear, i.e., has an infinite radius of curvature for the purpose of forming a support surface for the pipe. The upper circumferential section Ui1 is convexly curved, more strongly curved than the opposing circumferential sections Ui1 in the corrugated pipe design A in Fig. 1a.

[0033] It is important that for all corrugated pipe designs A to D shown, as can be seen from the Fig. 1a to 1d, from the comparison of the profiles Ui and Ua, the profile height H is greater in the strongly curved circumferential sections Ui2 than in the circumferential sections Ui1. Within the circumferential sections Ui2 and Ui1, the profile height H is approximately constant, with a minimum of the profile height H being formed in the central region of the slightly curved circumferential sections Ui1. In the region of the transition between the circumferential sections Ui2 and Ui1, the transition between the large profile height H and the smaller profile height H is continuous in the exemplary embodiments shown in the figures, as can also be seen from the profiles Ui and Ua in the Fig. 1a to 1d can be seen.

[0034] The wave profile parameters H, B, T, A and α are in the Fig. 1.1x and y to Fig. 1.3x and y are shown in detail. These figures show three different corrugated profile variants, namely variants 1, 2 and 3. These corrugated profile variants are each used for the corrugated pipe versions A to D, which differ in cross-sectional shape. Fig. 1a to 1d realized.

[0035] The Fig. 1.1x and 1.1y show wave profile variant 1.

[0036] The Fig. 1.2x and 1.2y show wave profile variant 2.

[0037] The Fig. 1.3x and 1.3y show wave profile variant 3.

[0038] The figures marked with index x each show the section XX in the strongly curved circumferential section Ui2 of the Fig. 1a to 1d. The figures labelled with index y each show the section YY into the less curved or straight circumferential section Ui1 of the Fig. 1a to 1d.

[0039] In the Fig. 1.1x and 1.1y to Fig. The profile parameters shown in 1.3x and 1.3y are H profile height or wave height of the wave profile; B Wave width of the wave profile; T pitch of the wave profile; A / 2 wave base width; α wave rise angle.

[0040] From the comparison of the sectional views designated with index x Fig. 1.1x, Fig. 1.2x and Fig. 1.3x (section plane XX in the circumferential section Ui2) with the sectional views designated by index y Fig. 1.1y, Fig. 1.2y and Fig. 1.3y (section plane YY in the circumferential section Ui1) shows how the profile parameters vary over the circumference Ui.

[0041] In the following, the profile parameters H, B, T, α, A / 2 from section plane XX with index x and from section plane YY with index y are compared. The following relationships result for the individual profile variants 1, 2, and 3: Wave profile variant 1 ( Fig. 1.1x and 1.1y) Hx>Hy Bx=By Tx=Ty αx=αy Ax / 2 <Ay / 2 Wave profile variant 2 ( Fig. 1.2x and 1.2y) Hx>Hy Bx>By Tx=Ty αx<αy Ax / 2 <Ay / 2 Wave profile variant 3 ( Fig. 1.3x and 1.3y) Hx>Hy Bx <By Tx=Ty αx>αy Ax / 2=Ay / 2

[0042] The corrugated pipes that implement profile variants 1, 2 and 3 differ in the following technical properties: Corrugated pipes in which the corrugated profile is designed according to corrugated profile variant 1 have manufacturing advantages. These lie in the fact that the mold jaws used for the production of such corrugated pipes can be manufactured particularly advantageously. These mold jaws can be manufactured by, in a first step, producing the inner mold surface of the mold jaws of a pair of mold jaws over the entire circumference, e.g. by milling, with a uniform corrugated profile over the entire circumference, uniform with the profile parameters of the section plane XX, i.e. over the entire circumference with the parameters Hx, Bx, Tx, Ax / 2, αx. In a second step, the corrugated profile thus produced to be uniform over the entire circumference is then further processed by milling exclusively in the circumferential sections Ui1, specifically in the sense of reducing the profile height Hx to the profile height Hy.The additional profile parameters Bx, Tx, Ax / 2, and αx are automatically generated in these profile sections. The two-stage manufacturing process possible with this wave profile variant makes the production of the mold jaws very simple, i.e., simpler than the single-stage production of mold jaws with different wave profiles in different circumferential sections by milling.

[0043] The forming jaws, which are manufactured in two stages as described above, produce corrugated pipes with a corrugated profile according to profile variant 1 when used in the corrugator. Corrugated pipes with a corrugated profile according to profile variant 1 are therefore advantageous due to their ease of production. The rigidity against compressive loads due to external pressure on the opposing, less curved or flat sides and the bendability of the corrugated pipe for installation purposes are sufficiently good, as a compromise.

[0044] Such a pair of mold jaws 20 with left mold jaw 21 and right mold jaw 22 and on the inner side of the mold jaws facing each other formed inner mold surface 25 is shown in Fig. 2 shown.

[0045] Regarding the properties of corrugated pipes according to corrugation profile variants 2 and 3: Corrugated pipes with a corrugated profile according to profile variant 2 have a wider corrugation shape and therefore increased rigidity against pressure acting on the opposing flat sides of the corrugated pipe.

[0046] Corrugated pipes with a corrugated profile according to profile variant 3 have a particularly narrow corrugation shape and provide particularly good flexibility during installation of the corrugated pipes.

[0047] A common feature of the corrugated pipes with a corrugated profile of profile variants 1, 2 and 3 is that they each provide a significantly higher profile height H in the circumferential sections of greater curvature, i.e. in the circumferential section Ui2, than in the circumferential sections of lesser curvature, i.e. in the circumferential section Ui1. This common property of profile variants 1, 2 and 3 is essential in order to obtain large cross-sectional areas with the corrugated pipes for the given non-circular cross-sectional shape, which in the case of ventilation pipes are advantageous for the flow through the pipes and in the case of pipes for a large storage volume for guiding cables or the like, and in both cases to obtain high compressive strength against damage due to external pressure, in particular when the pressure is applied to the opposite flat sides of the corrugated pipe. Reference symbol: RA axis of the corrugated pipe, pipe axis a1 major axis of the pipe cross-section a2 minor axis of the pipe cross-section Ua outer circumference Ui inner circumference Ui1 circumferential section of weak curvature Ui2 circumferential section of strong curvature R1 radius of curvature of weak curvature, large radius of curvature R2 radius of curvature of strong curvature, small radius of curvature H Wave height of the wave profile B Wave width of the wave profile T Division of the wave professional A / 2 wave base width α wave rise angle 1 corrugated pipe 1a corrugated outer pipe 1i inner tube 10 Wave profile 10b Wellenberg 10t wave trough 20 pairs of mold jaws 21 first mold jaws 22 second mold jaws 25 inner forming surface of the pair of forming jaws QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited non-patent literature

[0000] DIN EN ISO 61386-24

[0010]

Claims

[1] Plastic corrugated pipe for air conditioning and / or ventilation technology, designed as a single-layer or double-layer corrugated pipe (1, 1a), which has a corrugated profile (10) that forms the outside of the corrugated pipe (1, 1a), wherein it is provided, - that the corrugated profile (10) is formed from wave crests (10b) arranged one behind the other in the direction of the axis (RA) of the corrugated pipe (1, 1a) with wave troughs (10t) arranged between immediately adjacent wave crests (10b), - that the outer circumference (Ua) of the wave profile (10) is formed by the outer circumference of the wave crests (10b) and is non-circular or round, - that the inner circumference (Ui) of the wave profile (10) is formed by the outer circumference of the wave troughs (10t) and is non-circular, characterized by , - that the inner circumference (Ui) has one or more circumferential sections (Ui2) with a strong curvature (R2) and one or more circumferential sections (Ui1) with a weak curvature (R1), wherein in at least one of the circumferential sections (Ui2) with a strong curvature (R2) the wave profile (10) has a greater wave height (H), preferably at least on average a greater wave height (H), than in at least one of the circumferential sections (Ui1) with a weak curvature (R1); and - that the shape of the outer circumference (Ua) is non-circular and elliptical, wherein, in a modification of the elliptical shape, both of the mutually opposite longitudinal sides of the outer circumference (Ua), which are assigned to the circumferential sections (Ui1, Ui1) of the inner circumference (Ui) with slight curvature (R1, R1), are flattened and parallel with a linear course at least in sections; and - that the shape of the inner circumference (Ui) is elliptical, wherein the opposing circumferential sections (Ui1, Ui1) are convex with a slight curvature (R1, R1); and - that the outer cross-section of the corrugated pipe (1, 1a) formed by the outer circumference (Ua) of the corrugated profile (10) has a cross-sectional height aligned along the minor axis (a2) of a minimum of 48.5 mm to a maximum of 52.0 mm and a cross-sectional width aligned along the major axis (a1) of a minimum of 139.7 mm to a maximum of 142.3 mm. [2] Plastic corrugated pipe according to claim 1, characterized by that the inner circumference (Ui) has at least two, preferably opposite, circumferential sections (Ui2) with strong curvature (R2) and at least two, preferably opposite, circumferential sections (Ui1) with weak curvature (R1). [3] Plastic corrugated pipe according to one of the preceding claims, characterized bythat two adjacent circumferential sections (Ui1, Ui2) of the inner circumference (Ui), one of which is designed as a circumferential section (Ui2) of strong curvature (R2) and the other as a circumferential section (Ui1) of weak curvature (R1), continuously merge into one another with regard to the different wave height (H) of the wave profile (10) and / or with regard to their different curvature (R2, R1), preferably forming a continuous transition section. [4] Plastic corrugated pipe according to one of the preceding claims, characterized bythat within one or more, preferably each of the circumferential sections (Ui2) with a strong curvature (R2) in the wave profile (10) along the circumferential section, the wave height (H) and / or the curvature (R2) of the circumferential section is constant or variable, preferably forming a preferably convex maximum or forming a plurality of maxima, preferably alternately variable. [5] Plastic corrugated pipe according to claim 4, characterized by that the course of the varying profile height (H) and / or curvature (R2) along the circumferential section (Ui2) of strong curvature (R2) is continuous. [6] Plastic corrugated pipe according to one of the preceding claims, characterized bythat within one or more, preferably each of the circumferential sections (Ui1) with slight curvature (R1) in the wave profile (10) along the circumferential section (Ui1), the wave height (H) and / or the curvature (R1) of the circumferential section is designed to be variable, preferably varying to form a minimum, preferably varying alternately. [7] Plastic corrugated pipe according to claim 6, characterized by that the course of the varying wave height (H) and / or curvature (R1) along the circumferential section (Ui1) of weak curvature is continuous. [8] Plastic corrugated pipe according to one of the preceding claims, characterized by , that along the inner circumference (Ui) in the wave profile (10) the profile parameters wave height (H) and wave width (B) vary and preferably additionally also wave root width (A / 2) and / or wave rise angle (α) and / or pitch (T) vary or are varied, in that in the circumferential section (Ui2) of strong curvature (R2) the wave height (H) has the value H2, the wave width (B) has the value B2, the wave root width (A / 2) has the value A2 / 2, the wave rise angle (α) has the value α2 and the pitch (T) has the value T2, and in the circumferential section (Ui1) of slight curvature (R1), the wave height (H) has the value H1, the wave base width (A / 2) has the value A1 / 2, the wave rise angle (α) has the value α1 and the pitch (T) has the value T1, where the wave height (H) and the wave width (B) form the following relationship: - Relation 1 (wave profile variant 1): H2 > H1 and B2 = B1 or - Relation 2 (wave profile variant 2): H2 > H1 and B2 ≠ B1, preferably B2 > B1 or - Relation 3 (wave profile variant 3): H2 > H1 and B2 < B1 [9] Plastic corrugated pipe according to claim 8, characterized by , Relation 1.1: that relation 1 (wave profile variant 1) applies in combination with one or more of the following relations: - A2 / 2 < A1 / 2 - α2 = α1 - T2 = T1 or Relation 1.2: that relation 2 (wave profile variant 2) applies in combination with one or more of the following relations: - A2 / 2 < A1 / 2 - α2 ≠ α1, preferably α2 < α1 - T2 = T1 or Relation 1.3: that relation 3 (wave profile variant 3) applies in combination with one or more of the following relations: - A2 / 2 = A1 / 2 - α2 ≠ α1, preferably α2 > α1 - T2 = T1

Images