TW201641179A - Method for forming a tubular body, meandering tubular body and use thereof - Google Patents

Abstract

The invention relates to a method for forming a tubular body, comprising the following steps: making available a tubular body having a first and a second tube end, filling the tubular body with a liquid, closing the tubular body, and forming the tubular body.

Description

Method of forming a tubular body, curved tubular body and use thereof

According to a first aspect, the invention relates to a method of forming a tubular body. According to another aspect, the invention is directed to a curved tubular body made by such a method. According to another aspect, the invention relates to the use of such a tubular body.

A well-known procedure for forming a tube system. After fabrication, the tubular body is generally in the form of an elongate, substantially uncurved form. However, since in practice the tubular body is used not only along the straight transport section, the mounting position may sometimes require fluid to be transported along the curved path by the tubular body, such as at the corners, and in this case is not always possible or desirable. The branch line, the flange mounting elbow, and the like, on the one hand, need to be able to bend the tube body, for example, by forming. On the other hand, it is desirable to be able to form the cross-sectional shape of the tubular body so as to be able to rest the tubular body through a predefined opening section, or to shape the cross-section of the tubular body as close as possible to the predetermined opening cross-section. The latter is important in particular when the tubular body is used as a cooling element to enable the best possible heat transfer between the tubular body and the body to be cooled.

One particular challenge in forming the tubular body is to prevent collapse or buckling of the tubular body or unwanted deformation of the tubular body in some other manner and to obtain only the deformations expected in the forming procedure. To achieve this, sand is used as a filler in the prior art. The sand fills the internal section of the tubular body and prevents collapse or unwanted recesses of the tubular body during formation, provided that sufficient packing density is achieved.

Even the method is for simple forming procedures (such as making individual bend radii or making tubes) Non-circular cross-sections are possible, and there is still the problem that in the case of more complicated forming procedures, such as making curved tubular bodies, it may no longer be possible to completely remove sand from the tubular body after the formation procedure. Therefore, in the prior art, it is impossible to make a complicated tubular shape in a single piece, such as a curved tubular body.

In the German patent application on which the priority is based, the German Patent and Trademark Office states the following documents: DE 694 02 051 T2, DE 196 16 484 A1, EP 0 099 714 A1, DE 199 52 508 A1 and DE 10 2010 018 162 B3.

Accordingly, the basic object of the present invention is to indicate a method of forming a tubular body that eliminates the disadvantages described above as much as possible. In particular, the basic object of the present invention is to indicate a method of forming a tubular body that allows for greater flexibility in forming complexity.

The present invention achieves the basic object by the features of the first aspect of the invention in the case of one of the types specified in the opening paragraph. Specifically, the method according to the present invention has the steps of: providing a tube having a first tube end and a second tube end; filling the tube with a liquid (preferably water); closing the tube; The tube body is formed. The present invention takes advantage of the insight that water (especially in a liquid or gaseous state) can be removed from the tube after formation of the tube without leaving a residue, regardless of the complexity of the tube, as long as one end or preferably two The tube ends are opened again after formation. Furthermore, the present invention takes advantage of the fact that a liquid, such as water or a suitable oil, although it is in a liquid state, may still be difficult to compress and thus ensure sufficient stability of the internal tube volume, provided that the tube is completely filled and closed.

In a particularly preferred development of one of the methods, the method further comprises the step of pressurizing the liquid in the tube prior to the forming step. Through the pressurization of the liquid, the liquid is as preloaded. Physically, the liquid is not completely incompressible. However, it has been found that for the purpose of the method according to the invention, sufficient incompressibility or sufficiently low compressibility can be obtained when water is used, and this can be further improved even by subjecting the water to pressure prior to formation. Pressurization can provide an indication of the complete filling of the tube. A particular advantage associated with pressurization is as follows: if, for example, a crack occurs during the formation of the tubular body Upon leakage, the pressurized liquid will immediately escape from the interior of the tube. This escape will be easy to detect. Therefore, the pressure check can be performed simultaneously during formation. If no liquid escapes prior to completion of the forming procedure, the operator immediately knows that the tubing is pressure sealed at least up to the pressure that the tubing has previously received from the inside. This shows a big economic advantage.

The liquid preferably withstands a pressure of 20 bar or more, particularly preferably in the range of from 50 bar to 200 bar.

In a preferred embodiment of the method, the forming step includes introducing one or more bend radii into the tube. In short, the more effective the advantage of using a liquid as an internal stabilizer, the more complex the geometry of the tube and thus the introduction of more bending radii into the tube.

In another preferred embodiment, at least one of the bending radius or the plurality of bending radii, preferably the plurality of bending radii or the bending radii are less than three times the diameter of the tube. However, in the case of the conventional tube bending method of the prior art, a minimum bending radius from about one-fifth of the diameter of the tube is as low as (easily) three times the maximum value is regarded as a basis, according to the present invention. The method is attributed to the use of a liquid, in particular a pressurized liquid, as an internal stabilizer, allowing for significantly greater bending, and this results in a significantly more compact possible bending radius. In a preferred embodiment, the achievable radius of curvature is in the range of less than three times the diameter of the tube to about two times the diameter of the tube, wherein as previously mentioned, the bending radius is also known to be used as the tube. The material of the body depends in particular on its wall thickness. For example, the above-mentioned bending radius can be realized in the case of a tube having a diameter of 12 mm, a wall thickness of 1 mm, and stainless steel as a material.

In another preferred embodiment of the method, the forming step comprises: changing the tube cross section of one or more segments of the tube body or the tube cross section of the entire tube body to a substantially polygonal cross-sectional shape, in particular The best change is a substantially rectangular shape. A generally polygonal or substantially rectangular shape is considered to mean that the angle of the section is within the technically feasible range. If a section of the tube is deformed such that it forms one or more edges with a polygonal shape, in particular a rectangular shape, for the overall section, it is desirable to have a small edge radius to remain within On the side and on the outside. This can be ignored for the purpose of understanding the concept of the substantially polygonal or substantially rectangular cross-sectional shape.

Changing the cross-section of the tube into a substantially polygonal or substantially rectangular cross-sectional shape is preferably accomplished by placing one or more segments of the tubular body or the entire tubular body in a mold and then applying the force The tube is formed to match the mold. According to the invention, a force is applied from the outside of the mould or the tubular body and/or by the force exerted by the mould itself, which acts, for example, in the manner of a punch. According to the invention, for example, there is a preference for deforming the tubular body by means of a punch or a roller (for example by means of a straightening roller).

In another embodiment, the method is developed wherein a plurality of bending radii are introduced into the tubular body and wherein the forming step further comprises bending the tube into a curved shape, wherein the curved shape has one or more substantially The pipe segments are not bent, each of the pipe segments abutting one or more of the bending radii.

As a further preferred option, the method includes the step of discharging liquid from the tubular body by a pressure relief valve if the pressure exceeds a predetermined value during formation. Preferably, this is accomplished by closing at least one of the ends of the tubular body with an overpressure limiting valve that is significantly increased by up to 1% to 10% each time the pressure is attributed to the formation process. When more or more, the liquid is discharged. Thereby, the following result is achieved: when the pipe cross section is changed by applying a force from the outside, the volume of the pipe body is sometimes reduced. In order to ensure that the liquid medium escaping from the section of the just deformed tubular body does not cause a convex or undesired deformation of the tubular body at some other point, according to this embodiment, the liquid is selectively discharged to make the tubular body The pressure remains substantially constant. Depending on the design of the tube, different limit values can be defined here. For example, in the case where the wall thickness is 1 mm and stainless steel is used as the material, a limit value of a pressure limit of about 50 bar has been confirmed to be appropriate.

In another preferred embodiment of the method according to the invention, the method further comprises the step of monitoring the fluid pressure by a pressure sensor during formation. In addition to the fact that the visual monitoring of the liquid pressure can be carried out by observing the pressure relief valve, There is a preference for quantitative detection of pressure rise in the tube in order to more accurately control the formation process, and a well-known pressure measurement sensor is preferably used for this purpose.

The method according to the invention has also been proven in particular by a tube formed from a steel material, in particular stainless steel or structural steel.

According to a second aspect of the invention, the basic object of the invention is to indicate a pipe body suitable for cooling a generator, wherein the generator is specifically used in the form of a multi-pole synchronous generator of a wind power plant Generate a current.

The present invention achieves this object, wherein the tubular body is designed to have the features of claim 12. Specifically, the curved tubular body has a plurality of bending radii, preferably having a bending radius smaller than one third of the diameter of the tube, and a plurality of substantially non-curved segments that are adjacent to the bending radii and preferably none. Bending, wherein at least one, preferably plural or owner of the substantially unbent sections has a generally rectangular cross section.

Where reference is made above and below to a substantially unbent section of the tubular body, this will be considered to mean that the tubular body is designed to be unbent (ie straight) in such segments, or at least The curvature is so small that it can be introduced into the recess of the generator and preferably leans against the opposite wall of the recess to allow heat transfer. If there is a slight curvature in the depth direction of the groove, the curvature is extremely small here. According to the present invention, even if there is a slight curvature transverse to the depth of the groove (i.e., in the direction toward or away from the wall of the groove), the segment can be moved into the groove by elastic deformation. Underneath, presents a substantially unbent section.

The tubular body according to the present invention preferably has a range of between 0.5 mm and 3.5 mm, particularly preferably one of a wall thickness ranging from 1 mm to 2 mm.

As a further preferred option, the pipe system according to the invention is formed from a steel material, in particular stainless steel or structural steel. It is recognized that there are materials that allow for significantly larger changes due to higher ductility, such as copper tubes. However, the preference according to the invention is to design a tube with the smallest possible conductivity, in particular for use in a generator for generating current. fundamental The tube according to its curved shape also acts as a coil and during the operation of the generator, when the pole piece moves past the curved groove, it can cause power loss or interference field, and the power loss or interference field can be borrowed. Keep it low by the right choice of materials.

Thus, according to a third aspect, the invention relates to bending a tubular body in one of the embodiments according to one of the embodiments described above in a generator.

In particular, the present invention achieves the goal of carrying out the cooling of the generator by means of the most economical means and allowing the coolant to be carried as leak-free as possible.

Given the above considerations, it is preferred to use a curved tube system according to one of the preferred embodiments described above, since it has been (implicitly) checked for compactness during the manufacture of the tube.

According to the invention, the curved tubular body is particularly preferably used as one of the multi-pole synchronous generators designed as one of the wind power plants. The generator, particularly the stator of the generator, has a plurality of grooves in which a winding, preferably the stator winding, is disposed. A plurality of substantially non-curved tube segments of the generally rectangular cross-section of the tubular body are introduced into the grooves. As the cooling liquid then flows through the tube, the heat generated by the stator windings can be dissipated directly from the groove, and at the same time the presence of heat in the stator can be prevented.

In the case of a synchronous ring generator in a gearless wind power plant, the term "multipole" is taken to mean a plurality of stator poles, in particular one of at least 48 stator teeth, often even More stator teeth, in particular 96 stator teeth or even more stator teeth. The magnetically active region of the generator (i.e., both the stator (also referred to as an armature) and the rotor) is disposed in an annular region surrounding the axis of rotation of the synchronous generator. Thus, in particular, there is no material carrying the current or electric field of the synchronous generator from 0% to at least 50% of the radius of the air gap. In particular, this internal space is completely vacant and, in principle, can also be accessed. This region can often also constitute from 0% to 50% of the radius of the air gap, in particular up to 0% to 70% or even 0% to 80% of the air gap radius. Depending on the configuration, there may be a support structure in this inner region, but this is in some The embodiment can be designed for axial offset. By their role, such synchronous generators in a gearless wind power plant are slow-rotating generators. Here, the term "slow rotation" should be taken to mean a speed of less than 40 revolutions per minute, specifically about 4 revolutions per minute to 35 revolutions per minute, depending on the size of the power plant.

In the undeformed state of the tubular body 1 shown in Figures 1 to 3, it has a substantially cylindrical cross section and is not curved, as can be seen in Figure 1. In order to prepare the forming step, the tubular body 1 is tightly closed in a first end section 2 by means of a closure 3 (for example a blind plug). A second closure member 5 is inserted into an opposite second end section 4. The second closure 5 is designed, for example, as a check valve having an overpressure limiter.

The tubular body 1 is preferably filled with liquid via a second closure 5 and is for example pressurized at a pressure in the range from one of 50 to 200 bar. The tube is then compactly closed by a check valve as desired, wherein the pressure limiter as desired is designed to draw liquid from the tube over a predetermined pressure within the body 1. The inside of 1 is discharged.

The forming step can then be carried out using a filled and sealed, preferably pressurized, tubular body 1. In the illustrative embodiment shown, the tubular body 1 is first placed in a tube bending device 100, as shown in FIG. The tube bending device 100 holds one of the first legs of the tubular body 1 against a stopper 101. A lever 103 causes the tubular body 1 to bend in a direction A of the arrow about a stop pin 105. Due to the filling of the pipe body 1 with a liquid, the pipe bending occurs in the case where the pipeless section collapses, and one state as shown in Fig. 2 is realized when the bending process is carried out several times.

The tubular body shown in Fig. 2, which is bent into a curved shape and exhibits the semi-finished product of the method of the illustrative embodiment shown, has a plurality of substantially non-curved sections 7, each of which is configured to abut the bending radius 9 No bending.

Next, the cross section of the tube which is substantially unbent section 7 is preferably changed from the state shown in Fig. 2. This is accomplished by placing substantially unbent sections 7 one after the other in a mold 203 of a stamping apparatus 200, as shown in FIG. The mold 203 is composed of two parallel bars, for example, which are equally defined, for example, to have a slot width C and preferably one of the same slot depths. One of the rectangular sections in the form of a shape.

By repeatedly moving a punch 201 up and down in the direction of the arrow B, the tubular body 1 is subjected to an external force in the mold 203 which causes deformation so that the tube section is shaped to match the section of the slot.

A pressure measuring sensor 11 designed to monitor the internal pressure of the liquid is preferably disposed on the second closure member 5. If a predetermined pressure value is exceeded, there is a possibility that the liquid is manually discharged or a pressure relief valve is automatically opened when the pressure is exceeded to take into account that the volume of the inside of the pipe body 1 is attributed to the shape change caused by the punching device 200. The decrease.

As can be seen from the illustrative embodiments described above, the method according to the present invention can be used for both combined bending and changing of the shape of the cross-section of the tube. However, the advantages according to the invention, which stabilize the volume of the tubular body 1 by means of a preferably pressurized liquid, also play a role in two individual processing steps, ie when only bending of the tubular section occurs or only the shape of the tubular section occurs One of the changes. It has been found that the use of water allows for sufficient stability and environmental compatibility of the water is considered to be beneficial for its use.

As an alternative, the use of oil or the like is also envisaged.

1‧‧‧pipe body

2‧‧‧First end segment

3‧‧‧Closed

4‧‧‧second end segment

5‧‧‧Second closure

7‧‧‧Generally not curved

9‧‧‧Bending radius

11‧‧‧Pressure measuring sensor

100‧‧‧ tube bending device

101‧‧‧Retainer

103‧‧‧Leverage

105‧‧‧stop sales

200‧‧‧ Stamping device

201‧‧‧ Punch

203‧‧‧Mold

A‧‧‧ arrow direction

B‧‧‧ arrow direction

C‧‧‧Slot width

The invention will be described in more detail hereinafter with reference to the accompanying drawings, in which: FIG. 1 shows a first method state during fabrication of a curved tubular body; FIG. 2 shows one of the methods according to FIG. The second method state; and FIG. 3 shows a third method state according to one of the methods of FIGS. 1 and 2.

1‧‧‧pipe body

2‧‧‧First end segment

3‧‧‧Closed

4‧‧‧second end segment

5‧‧‧Second closure

100‧‧‧ tube bending device

101‧‧‧Retainer

103‧‧‧Leverage

105‧‧‧stop sales

A‧‧‧ arrow direction

Claims (13)

A method of forming a tubular body, comprising the steps of: providing a tubular body having a first tubular end and a second tubular end; filling the tubular body with a liquid; closing the tubular body; and forming the tubular body. The method of claim 1, comprising the step of pressurizing the liquid in the tube prior to the forming step. The method of claim 2, wherein the liquid is subjected to a pressure of 20 bar or more, preferably in a range of from 50 bar to 200 bar. The method of any of the preceding claims, wherein the forming step comprises introducing one or more bending radii into the tube. The method of claim 4, wherein at least one of the bending radius or the plurality of bending radii is less than three times the diameter of the tube, preferably less than three times the diameter of the tube to about twice the diameter of the tube. in. The method of claim 1, 2 or 3, wherein the forming step comprises: changing a tube cross section of one or more segments of the tube body or a tube cross section of the entire tube body to a substantially polygonal cross-sectional shape, in particular Preferably, the shape is changed to a substantially rectangular cross-sectional shape. The method of claim 6, wherein in order to change the cross section, the tube body is placed in a mold and is applied by The force is preferably formed by a punch or a roller to match the mold. The method of claim 1, 2 or 3, wherein a plurality of bending radii are introduced into the tubular body, and the forming step further comprises: bending the tubular body into a curved shape, wherein the curved shape has one or more The pipe segments are not bent, and the non-bending pipe segments are each adjacent to one or more of the bending radii. The method of claim 1, 2 or 3, comprising the step of discharging liquid from the tubular body by a pressure relief valve if the pressure exceeds a predetermined value during formation. The method of claim 1, 2 or 3, comprising the step of monitoring the fluid pressure by a pressure measuring sensor during formation. The method of claim 1, 2 or 3, wherein the tube system is formed from a steel material, specifically stainless steel or structural steel. A curved tubular body produced by the method of any one of the preceding claims, comprising: a plurality of bending radii, preferably having a bending radius less than three times the diameter of the tubular; and a plurality of substantially non-bending The segments, which are preferably adjacent to the bend radii, are preferably unbent; wherein at least one, preferably a plurality, or the owner of the substantially unbent segments has a generally rectangular cross section. A use of a curved tubular body in a generator as claimed in claim 12, wherein the generator is designed to generate a current, in particular a multipole in a wind power plant In a synchronous generator, wherein the generator, preferably the stator of the generator, has a plurality of grooves in which a winding, preferably a stator winding, is disposed; the tube body has a plurality of substantially unbent pipe segments, and the non-bent pipe segments There is a generally rectangular cross-section in which the substantially non-curved sections of the tubular body are disposed in the grooves and there is a flow of cooling liquid through one of the segments.