WO2014161950A1

WO2014161950A1 - Method and forming device for a formed wire body and formed wire body

Info

Publication number: WO2014161950A1
Application number: PCT/EP2014/056722
Authority: WO
Inventors: Robert Kopetzky
Original assignee: Robert Kopetzky
Priority date: 2013-04-03
Filing date: 2014-04-03
Publication date: 2014-10-09
Also published as: EP2981373B1; DE102013005685A1; EP2981373A1

Abstract

The invention relates to a method for producing a formed wire body, an intermediate product (28) manufactured from at least one wire being axially compressed by a forming device (10), at least sections of said intermediate product being radially outwardly expanded against a negative mold (18) of the forming device such as to give it its final outer shape. At least sections of the negative mold (18) are carried along during compression such as to avoid any frictional forces at least between the expanding section of the intermediate product (28) and the moving section of the negative mold (18), or such as to at least reduce the frictional forces with respect to the axial movement of the intermediate product that act on the intermediate product during compression.

Description

Method and forming device for a wire molding

and shaped wire bodies

The invention relates according to the preamble of claim 1, a method for producing a wire shaped body in which a manufactured from at least one wire precursor is compressed by a forming device in the axial direction, wherein the precursor is at least partially expanded radially outwardly against a negative mold of the forming device that it gets its final outer shape. Furthermore, the invention relates to a forming device according to the preamble of claim 9 and a wire molding according to claim 1. 1

The production of shaped wire bodies has long been known. Usually, a precursor made of wire, for example, a wire-knitted tube portion, a wire-wound or wire-wound wire-wound wire cylinder, or the like, is provided as a preliminary product. As a precursor in the context of the present application, semi-finished products are understood that have already been plastically deformed in upstream forming steps, for example, to specifically form material compaction, but not yet have their final shape. The precursor is reshaped by means of plastic deformation in a correspondingly formed forming device for the finished wire shaped body. The shaping device is for this purpose equipped with a negative mold which is complementary to the finished outer shape of the finished wire shaped body.

As is shown time and again, in the case of preforming products of comparatively large axial length, which are compressed in their axial length during forming, irregularities in the structure often occur in the finished wire molded article. The shaped wire body varies in its compression over its axial length and thus, for example, in its flow resistance when the shaped wire body is used, for example, as a filter insert. Based on this prior art, it is an object of the invention to provide a method or a forming device for producing a wire shaped body, with or in the use of a wire shaped body produced is, which has a viewed over its length at least approximately constant compression.

According to the invention, this object is achieved by a method having the features according to claim 1 and in particular that the negative Fonn is at least partially entrained during compression such that frictional forces are prevented at least between the widening portion of the precursor and the moving portion of the negative mold, the Frictional forces are reduced at least but compared to the axial movement of the precursor, which undergoes the precursor during compression, are reduced. Furthermore, the object according to the invention is achieved by a forming device having the features according to claim 9.

By using a variety of stamps, negative molds and various controls the forming operations was trying to eliminate the irregularities in the compaction of the finished wire molding, but this was not successful. A detailed analysis of the above-mentioned problem revealed that the irregularities in the compaction of the finished wire-formed body were caused by the frictional forces arising during the forming between the outer surfaces of the precursor and the inner surfaces of the negative facing. Thus, the precursor is not only compressed during the axial compression, but at the same time expanded radially in sections. The expansion of the precursor during forming is hardly controllable, but occurs at different points in the longitudinal direction of the precursor considered. As a result, significantly increased friction occurs between the widened sections of the preliminary product and the inner wall of the negative mold, which in turn, due to the frictional forces counteracting the compression forces, leads to an unintentional support effect on the widened sections of the preliminary product. As a result, the precursor in the places where it is already expanded, additionally compressed, while adjacent portions of the precursor, which are not yet expanded, less compacted. For this reason, the finished finished product, viewed over its axial length, has a varying compression of the wire structure of the wire shaped body.

According to the invention, it is now proposed to carry the negative mold at least in sections during the compression of the preliminary product such that frictional forces are prevented at least between the widening section of the preliminary product. which, at least, are diminished. Due to the fact that frictional forces between the outer surface of the precursor and the inner surface of the negative mold, against which the precursor is indeed formed avoided or at least reduced, the problems described above no longer or only to such a small extent that unintentional support by the expanded portions of the precursor during axial upsetting no longer occurs. This ensures that the not yet expanded portions of the precursor can still be compressed and thereby in turn radially expanded, which also unfold these sections due to the moving negative form also no support effect that counteracts the upsetting process. As a result, then has the finished end product, namely the wire molded article produced by the process according to the invention a uniform over its axial length considered compression.

The uniform compression of the shaped wire body is for a variety of reasons of great advantage, since, for example, when using the wire shaped body as a filter for a mass flow, for example, a liquid or gas stream to flow through the wire shaped body, the wire shaped body over its entire length and also has at least approximately constant flow resistance over its cross section. Further advantages of the invention will become apparent from the following description, the dependent claims and the drawings.

Thus, in a particularly preferred variant of the method, it is proposed to use a precursor which has an opening extending in the axial direction, preferably a through opening into which a support element, for example a rod with a round or polygonal cross section, is inserted prior to upsetting. With the help of this rod, the precursor is supported during the upsetting from the inside, so that in the finished wire molded body inside the outer dimensions of the rod corresponding opening is maintained. The rod can be removed from the wire molding after the upsetting process.

If a precursor is processed which has a comparatively large axial extent, it is proposed to use a negative mold which is formed from two sectionally intermeshing form elements. The form elements are formed so that during the compression process at least one of the mold elements is carried and thereby engages with the other mold element in such a way that the mutually engaging portions of the mold elements form an at least approximately closed support surface, against which during compression radially expanding portions of the precursor are formed.

In a variant of the method according to the invention, a cut-off wheel extending transversely to the longitudinal direction is to be provided in the finished wire shaped body, which divides a through opening extending through the wire shaped body. For this purpose, it is proposed that in the pre-product already provided through opening the cutting disc is used, which is held pressed by the compression of the precursor and the associated compression and expansion of the precursor both outwardly and inwardly in the finished wire molding. In order to give the finished wire molded article, if necessary, in addition stiffness, it is proposed in a further variant of the method to provide the precursor with an additional Amierungsgestrick, fabric or knitted, which around or in of a first knitted wire, - or knitted finished precursor is used. During the forming, the two materials are then pressed together so that the finished end product is integrally formed.

In a particularly preferred variant of the method according to the invention is also proposed to preform an elongated wire initially in the form of a helical helical structure and insert the spirally preformed wire in the Umfor- device for forming the precursor and then transform the precursor with the Umformei device to form the wire molding ,

Unlike in the prior art usual, this process variant eliminates the production of an intermediate product, which must be prefabricated in a separate manufacturing process prior to the actual forming process of the wire molding. According to the invention, a conventional wire is preformed initially in the form of a helical helical structure, the term "helical helical structure" in the present application being understood to mean a single or multiple cylindrical helix or helix. mig preformed wire is then inserted directly into the forming device, wherein the preformed wire forms the precursor only in the forming device. After the wire has been cut off, the wire section inserted as a precursor in the shaping device is finally shaped into the shaped wire body with the aid of the shaping device. It should be noted that the wire is either separated during insertion into the forming device, or has already been separated before insertion into the forming device and is inserted as a wire section in the forming device.

During uniforming, adjacently disposed helical portions of the wire are engaged with each other and plastically deformed with each other so that after forming a defined but permeable to liquids and gases wire structure is maintained.

This variant of the method according to the invention avoids a large number of upstream production steps which have hitherto been customary in conventional production methods, such as preparing the wires prior to knitting, weaving or knitting, knitting, weaving or knitting the wires into endless intermediate products and the like Separating individual sections from the continuous intermediates, or unpacking and cleaning the tubing and mat sections previously separated from the continuous intermediate. Particularly advantageous in the inventive method is the use of a wire with polygonal, preferably rectangular or square cross-section. The very fact that the wire need not be knitted, woven or knitted in the present process makes the use of square-section wires possible in the first place. The use of a wire for the wire molding having a polygonal cross-sectional shape uniform over its length instead of using a wire whose cross-sectional shape is round has various advantages.

Thus, it has been shown that the use of a cross-sectional mehrecki -gen wire in the wire shaped body due to its previously made spiralförmi-vorverformung its spatial orientation over the length considered continuously changes in the wire shaped body targeted laminar and turbulent flows can be generated, which Specifically influence flow behavior. The turbu- In turn, lenten flows lead to a significant increase in the flow resistance of the wire shaped body compared to wire shaped bodies, which are made of wires with round cross-sectional shapes.

In order to be able to realize the same flow behavior, in particular a virtually identical flow resistance in the wire shaped body according to the invention, the length of necessary wire can be reduced compared to conventional wire shaped bodies of wires with a round cross section, due to the inherently unfavorable flow behavior of the wires with an angular cross section Nevertheless, an approximately constant flow resistance can be maintained.

The fact that a shorter wire length can be used in the wire molding according to the invention, in turn, leads to a reduction of the weight of the wire molding according to the invention compared to the weight of a conventional wire molding of wires with a round cross section. If, for example, a wire forming body is used as reference, which is made of a round wire with a wire diameter of one millimeter and a length of 1000 mm, one needs for a wire shaped body according to the invention when using for example a cross-sectionally square wire with an edge length of 0 respectively , 89 mm only 678 mm in length, resulting in a weight spam of approximately 32%. In a square cross-section wire with an edge length of 0.6 mm and a length of 1000 mm results in a weight saving of approximately 55% with approximately the same flow resistance.

When using a cross-section polygonal wire for the production of the shaped wire body, it is possible to save material significantly with constant flow behavior. It is also possible to selectively influence and adjust the flow behavior and the heat transfer behavior by selective selection of the cross-sectional shapes and wire lengths.

For the method according to the invention, it is particularly preferred to use a wire which has a rectangular or square cross-sectional shape, since these cross-sectional shapes can be produced simply by pulling the wire. So that the wire shaped body retains its outer shape after upsetting, especially when precursors of very fine wires were used for the production, it is proposed in a further variant of the method, the outer surface of the wire shaped body sections by joining, ie by welding or soldering, with further inner layers of the wire shaped body firmly connect.

According to a further aspect, the invention relates to a forming device for forming an intermediate product made of at least one wire in a wire shaped body, in particular using the method mentioned above. For this purpose, the shaping device has a negative mold, at least one forming punch which can be moved axially to compress the precursor and which cooperates with the negative mold for forming the intermediate product into the wire shaped body, and a housing for the forming punch and the negative mold. According to the invention, the negative mold together with the forming die is movable in such a way that frictional forces are prevented at least between the portion of the precursor which is expanding during the axial compression of the precursor and the moving portion of the negative mold, but the frictional forces are at least opposite the axial movement of the precursor. which undergoes the precursor during compression, are reduced. In a preferred embodiment, the negative mold has at least one mold element which cooperates with the forming punch during forming together with the forming punch and which is displaceably mounted in the housing and is adjustable together with the forming punch. The shaped element can either be adjusted independently of the forming die. In an alternative, particularly preferred embodiment, the mold element is firmly connected to the forming die and is carried along with the forming die. The mold element can be integrally or detachably connected to the forming die. The latter is advantageous if the forming device has to be quickly converted to different shaped wire bodies. Depending on the finished wire molding body is also proposed that the negative mold has two sections in one another fende mold elements which move axially during upsetting such that the already engaged sections of the mold elements form an at least approximately closed support surface, which during the shaping of the wire shaped body radially expanding portions of the precursor supported. Preferably, each forming element is associated with a forming die, which cooperates with the respective associated forming element for forming the shaped wire body. Alternatively, however, it is also possible to provide, for example, only one forming die, which is movable together with one of the mold elements, while the other mold element is fixed in a predetermined position. Furthermore, it is also conceivable that both mold elements are movable, while only one forming die is provided, and the precursor is supported on its opposite end of the forming die in the housing. In a particularly preferred embodiment of the forming device according to the invention, two forming punches are provided, wherein the respective form element projects from the end face of each forming punch. The forming dies are displaceably mounted in the housing along a common longitudinal axis and movable toward or away from one another. The two form elements are provided with complementary cooperating support fingers, which move axially together during the movement of the forming die, that the already engaged sections of the support fingers form an at least approximately closed support surface for the arranged between the Umformstempeln intermediate product. By oppositely acting form elements any resulting frictional forces are canceled during the upset against each other, so that a wire shaped body with a considered over its length particularly uniform compression can be made.

According to a second aspect, the invention relates to one of a mass flow, as a liquid flow or a gas stream, transverse to flowing through wire molding of at least one wire having a considered over its axial length flowed predetermined average Strömungswiders tand, based on the predetermined average Flow resistance in a range of a maximum of ± 5%, preferably in a range of not more than ± 2.5% over the axial length varies. The invention will be explained in more detail below with reference to two exemplary embodiments with reference to the drawing. Hereby shows: Fig. La - c three different operating positions of a first embodiment of a forming device according to the invention in a schematic representation:

Fig. 2 is a diagram in which, based on the axial length of a wire formed body produced with the forming device shown in Figs. 1 a to c, the compression of the wire material is shown.

Fig. 3 is a front view of a second embodiment of a forming device according to the invention;

Fig. 4 is a sectional view taken along section line A-A. by the forming device of Figure 3 in collapsed operating position.

Fig. 5 is a sectional view corresponding to Figure 4 of the forming device immediately before the upsetting process.

6 is an enlarged detail view of the end shown in Fig. 4 on the left

Forming device with an additionally inserted spacer sleeve;

7 is a perspective view of a forming die of the forming device of FIGS. 3 to 6; such as

8 is a front view of the forming die of FIG. 7.

1 a to c is a schematic representation of a first embodiment of a forming device 10 according to the invention shown in different operating positions.

The forming device 10 has a housing 12 which rests on a base plate 14. In the housing 12, a lower punch 16 is arranged, which is releasably secured to the base plate 14. In the housing 12, a negative mold 18 is further slidably received, which is guided in its lower portion on the lower punch 16. At the upper end of the housing 12, an upper punch 20 is slidably supported by means of an actuator (not shown) between a raised position in which he has moved out of the housing 12 and a lowered position in the direction of the lower punch 16 to move is. At the lower punch 16, a support member 22 is further held in the form of a cylindrical rod. The support element 22 projects beyond the negative mold 18 into a receiving opening 24 formed in the upper punch 20.

The negative mold 18 is likewise adjustable by means of an actuator (not shown) and, as will be explained later, is moved back and forth in the longitudinal direction of the housing 12 together with the upper punch 20.

In Fig. 1 a to c the forming process is shown, which will be explained in more detail below. First, the upper punch 20 is moved to its raised position in which the form closed by the negative mold 18 is open 26. Subsequently, in this embodiment, a hollow cylindrical preform 28 is inserted into the forming space 26, wherein the precursor 28 is pushed onto the support element 22. For example, the precursor 28 is a tube section knitted from a wire.

Thereafter, the upper punch 20 is lowered until it comes to rest on the end face of the precursor 28 while it is simultaneously inserted into the open end of the female mold 18. This operating position is shown in Fig. 1 a.

Now, the upper punch 20 is moved together with the female mold 18 in the direction of the lower punch 16, wherein the precursor 28 is compressed in its axial longitudinal direction. The movement of the negative mold 18 is adapted to the movement of the punch 20 so that the widening portions of the precursor 28, which arise during the upsetting process, with respect to the inner surface of the negative mold 18 no, or at best experience a slight relative movement. This intermediate position is shown in Fig. 1 b.

The upper punch 20 is now moved as far down until the precursor 28 is formed into its desired compressed final shape and the finished wire shaped body 30 is formed, as can be seen in the end position shown in Fig. 1 c. By the method of the negative mold 18, any resulting frictional forces between the inner wall of the female mold 18 and the outer surface of the precursor 28 are eliminated. In Fig. 2 is a schematic diagram of a diagram is shown in which, based on the finished end product, namely the wire molding 30, the compression over the axial length of the wire molding 30 is recorded. Like the diagram too can be seen, the wire molding 30 shows over its axial length considered an at least approximately constant compression.

3 to 8, a second exemplary embodiment of a forming device 40 is shown, the order Formei device 40 has a two-part housing 42 with a continuous axial bore 44. In the axial bore 44, two identically formed forming die 46 are slidably received, with reference to be explained briefly in FIGS. 7 and 8 below.

7 shows a perspective view of the forming punch 46. The forming punch 46 has a cylindrical flange 48, from the center of which a hollow cylinder-shaped punch portion 50 projects in a concentric manner. A total of four supporting fingers 52 are distributed uniformly around the stamping section 50 (see Fig. 8), which are fixedly connected to the stamping section 50 and protrude beyond it in the axial direction. The support fingers 52 are identical and designed as segments of a hollow cylinder. Viewed in the circumferential direction (see Fig. 8), the support fingers 52 are dimensioned so that in each case a recess 54 is maintained, the circle distance between each two adjacent support fingers 52 is slightly larger than the radians of each support finger 52nd

The two forming punches 46 are displaceably receivable in the axial bore 44, wherein the forming dies 46 are rotated relative to each other, that in each case the Stützfmger 52 of a forming punch 46 is inserted into the recess 54 of the other Umformstempels 46.

If an intermediate product 56 is to be reshaped, the preliminary product 56, which is a tube section knitted from a wire, is first drawn onto a support element 58. Subsequently, the support member 58 is introduced with the raised precursor 56 in the space formed by the support fingers 52 of the uniform punch 46. Thereafter, the forming die 46 are moved toward each other, wherein, as previously described, the support fingers 52 of a forming die 46 engage in the recesses 54 of the other forming die 46 and vice versa. During the subsequent course of the movement, the support element 58 is inserted from the one forming punch 46 inwardly into the bore 44 until the pre-product 56 mounted on the support element 58 rests with its two end faces against the end faces of the stamping portions 50 of the forming punch 46. Subsequently, the two forming dies 46 are moved further inward, wherein the precursor 56 is compressed axially. Due to the fact that the frictional forces arising on the support fingers 52 of the forming dies 46 moving towards each other are opposite, they lift up so that the precursor 56 experiences a uniform compression over its axial length. When the forming dies 46 move together, the support fingers 52 are moved axially into one another such that the sections of the support fingers 52 already in engagement form an at least approximately closed support surface for the intermediate product 56 arranged between the forming dies 46. Once the forming dies 46 have arrived in their end positions, in which they rest with their flanges 48 at the two end faces of the housing 42, shaping of the wire shaped body 60 is completed. Subsequently, the two forming dies 46 are moved apart again, the housing 42 moved apart and ejected the finished wire shaped body 60 together with the support member 58 from the housing 42.

If a shaped wire body 60 are to be produced, which has a different axial length, a spacer sleeve 62 is pushed onto the support fingers 52 and the punch portion 50 of the forming die 46, which limits the insertion of the forming die 46, if the respective spacer sleeve 62 on the front side of the housing 42nd comes to rest, as shown in Fig. 6, an enlarged detail view of the left in Fig. 4 shown end of the forming device 40th

Claims

claims

1. A method for producing a shaped wire body, in which a precursor produced from at least one wire is compressed by a Umformeinrich- device in the axial direction, wherein the precursor is at least partially radially outwardly against a negative mold of the forming device is expanded such that it has its final outer shape gets,

characterized,

that the negative form during compression at least partially carried such that frictional forces prevented at least between the expanding section of the precursor and the moving portion of the negative mold, the friction forces but at least against the axial movement of the precursor, the precursor during the Upsetting, are reduced.

2. The method according to claim 1, characterized in that the precursor has an opening extending in the axial direction, preferably a through opening, into which a support element is used before upsetting, which supports the precursor during upsetting from the inside.

3. The method according to claim 1 or 2, characterized in that the negative tive form of two sectional interlocking form elements is formed, which move axially during compression such that the already engaged sections of the mold elements form an at least approximately closed surface against which the radially expanding portions of the precursor during compression are formed.

4. The method of claim 1, 2 or 3, characterized in that the precursor preferably prepared by knitting, weaving or knitting up in the axial longitudinal direction through the precursor extending through-hole has, in which prior to upsetting a transverse to the axial longitudinal direction arranged separating disk is used, which is formed by the upsetting of the precursor in the finished wire molding.

5. The method according to any one of the preceding claims, characterized in that the precursor is made of a first wire mesh, knitted fabric or knitted from a first wire and a reinforcing knitted fabric or knitted fabric from a relation to the first wire thicker second wire.

6. The method according to any one of the preceding claims, characterized in that the precursor is formed, in which at least one elongated wire initially preformed in the form of a helical helical structure, the spirally preformed wire subsequently inserted into the forming device for forming the Vorproduk- tes and the precursor is then converted with the help of the forming device to the wire molding.

7. The method according to any one of the preceding claims, characterized in that the at least one wire has a polygonal, preferably rectangular or square cross-section.

8. The method according to any one of the preceding claims, characterized in that portions of the outer surface of the formed wire shaped body are joined together by joining.

9. Forming device for forming an intermediate product (28; 56) made of at least one wire into a wire shaped body (30; 60) having a negative mold (18), at least one forming punch (18; 46), which cooperates with the negative mold (18) for forming the precursor (28; 56) in the wire form body (30; 60), and a housing (12; 42) for the forming die (18; 46) and the negative mold (12; 18), characterized

that the negative mold (18) together with the forming die (18: 46) to the housing (12; 42) is movable such that frictional forces at least between the section of the precursor (28; 56) and the moving portion of the female mold (18), but the frictional forces are reduced at least with respect to the axial movement of the precursor (28; 56) experienced by the precursor (28; 56) during upsetting.

10. Forming device according to claim 9, characterized in that the negative mold has at least one during the compression together with the forming die (46) for forming the wire shaped body (60) cooperating mold element (52) which is displaceably mounted in the housing (42) and in common - Sam with the forming die (46) is adjustable.

1 1. Umformeinrittitung according to claim 9 or 10, characterized in that the negative form two partially interlocking mold elements (52) which move axially during compression such that the already engaged sections of the mold elements (52) at least one form approximately closed support surface, which supports the during the forming of the wire shaped body (60) radially widening portions of the precursor (56), that each mold element (52) is associated with a punch portion (50) of the forming die (46), and that the mold elements (52 ) and the punches (50) cooperate to form the wire shaped body (60).

12. Forming device according to claim 1 1, characterized in that near the end face of each stamp portion (50) of the forming die (46) protrudes the respective Formelemcnt that the forming die (46) in the housing (42) along a common longitudinal axis slidably mounted and towards each other or that are movable away from one another, and that the two form elements are provided with complementary cooperating support fingers (52) which move into one another axially when the forming dies (46) move together so that the sections of the support fingers (52) already in engagement with each other are at least one form approximately closed support surface for the between the Umformstempeln (46) arranged precursor (56).

13. From a mass flow across to flow-through wire shaped body of at least one wire having a considered over its axial length flow th predetermined average flow resistance, based on the predetermined average flow resistance in a range of ± 5%, preferably in a range of a maximum of ± 2.5% over the axial length varies.