RU2384797C1 - Flexible conduit for fluid medium and procedure for its fabrication - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention refers to flexible conduit for fluid medium with several pipes (1) arranged parallel side by side, which at least at one end (9, 10) are equipped with common connecting element (11, 12); also tubes are imbedded into plastic body (6). Additionally the invention refers to the procedure for fabrication of flexible conduit (8) for fluid medium. The pipes are arranged in one plane. Section of pipes (1a-1f) between two ends (9, 10) is bent in form of meander so, that several waves follow one another in lengthwise direction of pipes.

EFFECT: invention simplifies fabrication of conduit of described type.

15 cl, 8 dwg

Description

The invention relates to a flexible conduit for a fluid with several pipes arranged parallel to each other, which at least at one end have a common connecting element and are embedded in a plastic body. In addition, the invention relates to a method for manufacturing a flexible fluid conduit, in which several pipes are placed parallel to each other, plastically deformed, embedded in plastic and provided with a common connecting element at least at one end.

Such a pipeline is known from patent document WO 2004/046601 A1. In accordance with this document, individual pipes are held along a helical line and cover a cavity that can be left free or filled with a core. For fluid flow, the sum of the cross-sections of all pipes is available. Due to the pipe along the helix, the pipeline has a certain flexibility.

Such pipelines are well suited for transporting fluids under high pressure and, depending on the circumstances, with high temperature in technical applications in which strong vibrations, significant relative movements and aggressive environmental conditions occur. Examples of use include mobile refrigeration units, in particular automotive CO ₂ air conditioners. In such applications, for installation reasons, it is desirable that the pipeline has a certain flexibility, and at the same time does not loosen due to this.

However, the production of such pipelines requires certain costs. To create a shape in the form of a helix, pipes located next to each other must be wound together around the core. This requires a certain skill. Machine production is possible only to a limited extent, unless you can use tools with a mechanical drive.

The basis of the invention is the task to offer such a flexible pipeline for a fluid that is easily manufactured.

In the case of a flexible pipe of the type mentioned above, this problem is solved due to the fact that the pipe section located between both ends is curved in the shape of a meander.

The meander shape, in which several waves in the longitudinal direction of the pipes follow one after another, is made much simpler than twisting several pipes placed parallel to each other along a helical line. Firstly, due to this, the process of plastic deformation is significantly simplified. In addition, a pipe with pipes curved in the form of a meander is generally more flexible than a pipe in which pipes are held along a helical line parallel to each other. Thus, the pipeline, made in the form of a meander, has additional advantages.

Moreover, each pipe should preferably have several curved sections in the form of an arc of a circle. A profile stamp that can be used to make circular arcs is relatively easy to make. In this case, the punches necessary for plastic deformation can be shaped as part of a cylindrical surface. If necessary, the arcuate sections can also be connected to each other via linear sections. However, as a rule, it is sufficient that the arcuate sections adjoin each other directly or at small intervals.

Alternatively or additionally, it can be provided that each pipe has sinusoidal arcuate sections. With sinusoidal arched sections, a more favorable flow through the pipeline is realized. With sinusoidal arched sections, the transition between two curved in opposite directions arched sections can be carried out so that the tangent passes at an angle of less than 90 ° to the longitudinal length of the pipeline. However, in principle, this can also be realized in the case of sections in the form of a circular arc.

Preferably, the radius of curvature of the arcuate portion is in the range of 1.5D to 5D, where D is the outer diameter of the pipe. With such a radius of curvature, an individual pipe does not overstrain when bending. If we are not talking about an arcuate section in the form of an arc of a circle, then the radius of curvature is the average radius of curvature over the entire arcuate section.

Moreover, it is preferable that the period length lies in the range from 3R to 10R, where R is the radius of curvature. The length of the period is the distance between the two maxima of the meander shape. This distance provides sufficient stretching or compression of the pipeline. With a greater distance, individual arcuate sections are slightly elongated, i.e., depending on the circumstances, they may have additional linear sections that run parallel to the longitudinal axis. If the arcuate sections are made only as circular arcs that are directly adjacent to each other, then the specified distance is equal to four radii of curvature.

Preferably, the plastic body has a meander shape. So, the flexibility of the pipes fully takes over the plastic body. A plastic body following the meander shape of the pipes is realized with relatively low material costs. Plastic has a certain flexibility or elasticity, so it can be deformed due to vibrations or changes in length along with the pipes.

Preferably, the pipes are spaced from each other with an intermediate space, the intermediate space being filled at least partially with plastic of the plastic body. So, individual pipes are separated from each other by a thin layer of plastic. This prevents mutual friction of the pipes against each other if the pipeline is subjected to vibrations during operation. Thanks to it insignificant mechanical wear is provided. In addition, noise generation or noise reduction is avoided.

Preferably one end of the pipeline is twisted relative to the other end of the pipeline. The twist angle between the two ends is preferably 90 °. The twist angle is the angle between the first plane in which pipes are placed next to each other at one end of the pipeline and the second plane in which pipes are placed parallel to each other at the other end of the pipeline. By twisting both ends around the longitudinal axis of the pipeline, relatively uniform mobility of the pipeline in all radial directions is obtained, i.e. in directions that extend perpendicular to the longitudinal axis of the pipeline.

It is also preferred that the pipes are made of metal, in particular steel or aluminum. Due to this, the stability of the pipeline increases. At the same cost, metal is more resistant to many fluids than plastic.

In the case of the above method, the problem is solved due to the fact that the section located between both ends of the pipes is bent in the form of a meander.

Square-wave plastic deformation is realized relatively easily, without the need for winding pipes.

A press die is preferably used for bending. A stamp is available quite often. For meander bending, you only need to use a suitable shape.

Preferably, pipes located in the same plane are deformed perpendicular to this plane. This is the easiest way to achieve meander bending. In essence, only a single movement in one direction is necessary.

Preferably, the pipes are filled with plastic before plastic deformation. This simplifies the design of the tool, preferably an injection mold, for sealing pipes into plastic. In essence, this requires only a form with a forming cavity in the form of a rectangular parallelepiped. Plastic bending pipes in a meander shape does not interfere.

It is also preferable that after plastic deformation the ends of the pipeline are twisted relative to each other at a certain angle, in particular 90 °. Although this requires an additional technological operation, twisting of the two ends results in increased flexibility in all directions.

The invention is further disclosed by the example of preferred embodiments, the description is accompanied by drawings. The drawings show the following.

Figure 1 is a top view of a pipeline with six parallel pipes without connecting elements and plastic.

Figure 2 is a side view of the pipeline in accordance with figure 1.

Figure 3 is a front view of the pipeline in accordance with figure 1.

Figure 4 - pipeline in accordance with figure 1 with a plastic body and connecting elements.

Figure 5 is a side view of the pipeline in accordance with figure 4.

6 is a front view of the pipeline in accordance with figure 4.

7 is a schematic view of a pipeline in which two connecting elements are twisted relative to each other by approximately 90 ° relative to the longitudinal axis.

Fig. 8 is a graph of the flexibility and hydraulic resistance of a pipeline versus a period length.

Figure 1-3 shows several pipes 1a-1f located parallel to each other. In this case, we are talking about six pipes 1a-1f. Despite this, more or less pipes may also be used.

Each pipe 1a-1f has an outer diameter D, in this embodiment it is 2.5 mm. In this example, the wall thickness of the pipe 1a-1f is 0.4 mm. Of course, other meanings are possible.

As can be seen from figure 2, the pipe 1 is bent in the form of a meander, i.e. they form a plurality of arched sections 2 which are adjacent to each other or connected to each other by small straight sections 3. The length of such a straight section 3 can be, for example, 4 mm. Also, the arcuate section 2 does not have to have continuous curvature, it may well have small, not shown in detail sections located parallel to the longitudinal direction 4.

The arcuate portion 2 has a radius R that lies in the range from 1.5D to 5D, where D is the aforementioned outer diameter of the pipes 1. With a diameter D of 2.5 mm, the radius of curvature is preferably from 3.75 to 12.5 mm . In this embodiment, the radius of curvature R is about 6 mm.

Arcuate sections 2 can be bent in the form of an arc of a circle. However, they can also have a sinusoidal shape. The transition points between the two arcuate sections 2 do not have to lie perpendicular to the longitudinal direction 4. For example, an angle of 45 ° is also possible (Fig. 7), which can occur at the transition between two sinusoidal arcuate sections.

The length of period A, i.e. the distance between two "maximums" or between two "zero points", i.e. the intersection of a plane lying in the middle in the longitudinal direction 4 is preferably from 3R to 10R, where R is the aforementioned radius of curvature. In this example implementation, the axial distance between two adjacent loops or waves, i.e. the length of period A is 24 mm.

If we are talking about sections 2 not in the form of an arc of a circle, then the radius R within section 2 varies. In this case, take the average radius.

As follows from Figs. 4-6, a group of pipes 5 formed by pipes 1a-1f is embedded in elastic plastic 6. Plastic 6 forms a plastic body. In each case, there are small intermediate spaces 7 between the pipes 1a-1f, into which the plastic 6 penetrates. This prevents mutual friction of the pipes 1a-1f if the pipe 8 shown in Figs. 4-6 is deformed. Such a deformation can occur if devices connected to both ends 9, 10 of the pipeline 8 change their position relative to each other. In essence, this change can occur in all directions in space.

At both ends 9, 10 of the pipeline 8, connecting elements 11, 12 are placed, these elements, for example, can be injection molded together with plastic 6 or connected to the pipes as separate parts. The connecting elements 11, 12 cover all pipes 1a-1f. In addition to the inlet and outlet of the fluid or the connection of any device, they are designed to hold the individual pipes 1a-1f in a certain position parallel to each other.

The manufacture of such a pipeline 8 is not difficult to implement using a press stamp. Pipes 1a-1f located in the same plane are deformed perpendicularly to this plane by means of a stamp. In this case, the resulting form may have arched or sinusoidal sections, it can be made in the course of one operation. It is only necessary to choose a shape of the tool that would allow to achieve the desired shape of the product.

Before plastic deformation of the pipes 1a-1f, it is already possible to produce plastic 6 and connecting elements 11, 12 or, respectively, to connect separate connecting elements to the pipes. For this, pipes 1a-1f, located in the same plane and lying parallel next to each other, are placed in the corresponding injection molding mold, then the plastic is filled 6. Then, after applying the plastic 6, plastic deformation may follow.

As can be seen from FIG. 7, after manufacturing the pipeline 8 shown in FIG. 5, both connecting elements 11, 12 can still be twisted relative to each other, for example, by 90 °, so that a relatively uniform mobility of the pipeline in all radial directions is obtained.

The pipes 1a-1f are preferably made of steel or aluminum, and other metals are acceptable.

On Fig schematically shows the dependence of the deformation resistance FL on the number X of waves. In the embodiment shown in FIG. 5, conduit 8 has eight waves. With an increase in the number of waves X, the deformation resistance FL decreases.

On the other hand, with an increase in the number of X waves, the hydraulic resistance SW increases, since with equal length the radii of curvature of the waves decrease.

Claims (15)

1. A flexible fluid conduit with several pipes parallel to each other and at least at one end have a common connecting element and embedded in a plastic body, characterized in that the pipes are initially in the same plane, and the pipe section (1a-1f), located between the two ends (9, 10), is bent in the shape of a meander so that several waves in the longitudinal direction of the pipes follow each other. 2. The pipeline according to claim 1, characterized in that each pipe (1a-1f) has several curved sections (2) in the form of circular arcs. 3. The pipeline according to claim 1, characterized in that each pipe (1a-1f) has several sinusoidal arcuate sections (2). 4. The pipeline according to claim 2, characterized in that the radius of curvature (R) of the arcuate section (2) lies in the range from 1.5D to 5D, where D is the outer diameter of the pipe (1a-1f). 5. The pipeline according to claim 4, characterized in that the length of the period (A) lies in the range from 3R to 10R, where R is the radius of curvature. 6. The pipeline according to any one of claims 1 to 5, characterized in that the plastic body (6) has the shape of a meander. 7. The pipeline according to any one of claims 1 to 5, characterized in that the pipes (1a-1f) are located relative to each other with an intermediate space (7) between them, and the intermediate space (7) is filled, at least partially, with plastic plastic body (6). 8. The pipeline according to any one of claims 1 to 5, characterized in that one end (9) of the pipeline (8) is twisted relative to the other end (10) of the pipeline (8). 9. The pipeline according to claim 8, characterized in that the twist angle between the two ends (9, 10) is 90 °. 10. The pipeline according to any one of claims 1 to 5, characterized in that the pipes (1a-1f) are made of metal, in particular steel or aluminum. 11. A method of manufacturing a flexible pipeline for a fluid in which several pipes are placed parallel to each other, plastically deformed, embedded in plastic and at least at one end provide a common connecting element, characterized in that the pipes are initially placed in one the planes and the section between the two ends (9, 10) of the pipes (1a-1f) are bent in the shape of a meander so that several waves in the longitudinal direction of the pipes follow each other. 12. The method according to claim 11, characterized in that a press die is used for bending. 13. The method according to claim 11 or 12, characterized in that the pipes (1a-1f) located in the same plane are deformed perpendicular to this plane (4). 14. The method according to any one of claims 11-12, characterized in that before plastic deformation, the pipes (1a-1f) are filled with plastic (6). 15. The method according to any one of claims 11-12, characterized in that after plastic deformation, the ends (9, 10) of the pipeline (8) are twisted relative to each other at a certain angle, in particular 90 °.

Images