An especially advantageous of the corrugated pipe
An especially advantageous of the corrugated pipe
An especially advantageous design of the corrugated pipes profile in accordance with the invention results if the outer contours of the small and of the large cross section are designed in an elliptical form. In this instance the large semiaxis of the small cross section 9 is parallel to and of the same size as the small semiaxis of the large contour cross section 7. The property that non-circular cross sections tend to deform under internal pressure to circular cross sections can be utilized for mutual compensation of this tendency by an alternating 90° rotation of adjacent elliptical cross sections.
The general instance for the application of a corrugated pipe geometry frequently requires a high bending flexibility in more than one bending plane. This property is achieved in that at least two sections of the corrugated-pipe geometry of the invention are series-connected with an adapted, different alignment of the planes of minimal bending strength. In this manner a practically unlimited mobility can be achieved for the corrugated pipe of the stackable plastic containers, viewed as a whole, even though a degree of freedom must be sacrificed in each individual section in favor of the increased tensile stiffness. The offset angle is preferably in a range of 20-160°. Care is to be taken when designing the transition from one section to the next that even here an uninterrupted, corrugation-free connection in the form of a ring, that is, of a short, plastic pallet section, is created in which the corrugation-free jacket lines of the one section end and the next ones, rotated by the angle, continue in order that the sections are continuously composed without the weak spot of a plastic container or constriction.
In order to be able to quantify the effect of the novel corrugated pipes geometry the corrugated-pipe profile of the invention shown in FIGS. 1a-1d was compared by means of finite element analysis with a conventional, symmetric, circular corrugated-pipe profile in accordance with FIGS. 4a-4d.A polymer material with 100 MPa isotropic material stiffness was assumed for the calculation. Loads were simulated on both profiles which represent typical operating conditions for air-conduction parts and coolant lines in the automobile sector.
An especially advantageous design of the corrugated pipes profile in accordance with the invention results if the outer contours of the small and of the large cross section are designed in an elliptical form. In this instance the large semiaxis of the small cross section 9 is parallel to and of the same size as the small semiaxis of the large contour cross section 7. The property that non-circular cross sections tend to deform under internal pressure to circular cross sections can be utilized for mutual compensation of this tendency by an alternating 90° rotation of adjacent elliptical cross sections.
The general instance for the application of a corrugated pipe geometry frequently requires a high bending flexibility in more than one bending plane. This property is achieved in that at least two sections of the corrugated-pipe geometry of the invention are series-connected with an adapted, different alignment of the planes of minimal bending strength. In this manner a practically unlimited mobility can be achieved for the corrugated pipe of the stackable plastic containers, viewed as a whole, even though a degree of freedom must be sacrificed in each individual section in favor of the increased tensile stiffness. The offset angle is preferably in a range of 20-160°. Care is to be taken when designing the transition from one section to the next that even here an uninterrupted, corrugation-free connection in the form of a ring, that is, of a short, plastic pallet section, is created in which the corrugation-free jacket lines of the one section end and the next ones, rotated by the angle, continue in order that the sections are continuously composed without the weak spot of a plastic container or constriction.
In order to be able to quantify the effect of the novel corrugated pipes geometry the corrugated-pipe profile of the invention shown in FIGS. 1a-1d was compared by means of finite element analysis with a conventional, symmetric, circular corrugated-pipe profile in accordance with FIGS. 4a-4d.A polymer material with 100 MPa isotropic material stiffness was assumed for the calculation. Loads were simulated on both profiles which represent typical operating conditions for air-conduction parts and coolant lines in the automobile sector.