DE102013110612A1 - Method for producing a fluid line - Google Patents

Abstract

The present invention relates to a method for producing a fluid line (100) having a sealing geometry (101), which comprises a first region (101-1) with a first material strength and a second region (101-2) with a second material strength A semi-finished product (103) comprising the steps of inserting (S101) the semifinished product (103) into a tool (105) having a first tool region (107-1) whose contour corresponds to a processing contour (109) of the semifinished product (103) and a second one Tool area (107-2) whose contour deviates from the processing contour (109) of the semifinished product (103); and massive forming (S102) the semifinished product (103) by means of the tool (105) for producing the sealing geometry with the first material strength in the first tool region (107-1) and the second material strength in the second tool region (107-2).

Description

The present invention relates to a method for producing a fluid line having a sealing geometry from a semifinished product, which comprises a first region having a first material strength and a second region having a second material strength.

For thick-walled fluid lines, as used for example for direct injection diesel engines, a connection geometry can be formed with a massive deformation at the tube ends of the later fuel line. The thus applied sealing geometry is sealingly connected in the vehicle with the connection component, such as an injector, a fuel rail or a pump. Due to the massive forming but hardened the material of the fluid line, so that often no sufficient sealing surface can be made with a connection partner.

It is the object underlying the invention to provide a method for producing a fluid line, which has a sufficiently elastic and soft sealing surface.

This object is achieved by the subject matter having the features of the independent claim. Advantageous embodiments of the invention are the subject of the figures, the description and the dependent claims.

According to a first aspect of the invention, the object is achieved by a method for producing a fluid line having a sealing geometry, which comprises a first region having a first material strength and a second region having a second material strength, from a semifinished product, with the steps of inserting the semifinished product into a tool having a first tool region whose contour corresponds to a processing contour of the semifinished product and a second tool region whose contour deviates from the processing contour of the semifinished product; and massive forming of the semifinished product by means of the tool for producing the sealing geometry with the first material strength in the first tool area and the second material strength in the second tool area. As a result, for example, the technical advantage is achieved that the surface of a sealing region of the sealing geometry can be made softer and applies better in the connection case to the opposite sealing geometry of a sealing partner. On the other hand, with a higher degree of deformation, a higher strain hardening is achieved in a part of the sealing geometry which does not serve directly the sealing. It can thus be made a total higher-strength component, without adversely affecting the sealing behavior of the sealing geometry.

In an advantageous embodiment of the method, the method comprises the step of cutting out the processing contour of the semifinished product by means of a separation method. As a result, for example, prior to insertion of the semifinished product into the tool, the technical advantage is achieved that any impact points, scratches or imperfections that are located on the surface of the semifinished product are separated from the semifinished product before massive forming. As a result, surface irregularities are no longer present at the sealing surface of the sealing geometry.

In a further advantageous embodiment of the method, the separation method is a cutting method with a shaped edge. As a result, the technical advantage is achieved, for example, that the separation process can be carried out in a simple and fast manner.

In a further advantageous embodiment of the method, the semifinished product is a metal tube with a tube end. As a result, for example, the technical advantage is achieved that a sealing geometry can be produced with a high stability.

In a further advantageous embodiment of the method, the processing contour of the tube end corresponds to the contour of the first tool region. As a result, for example, the technical advantage is achieved that the pipe end is not deformed during massive forming and retains its soft material properties.

In a further advantageous embodiment of the method, the processing contour of the pipe end is formed by a rounded edge of the pipe end whose radius of curvature corresponds to a radius of curvature of the first tool region. As a result, for example, the technical advantage is achieved that a spherical contour is used with good sealing properties.

In a further advantageous embodiment of the method, the first material strength is less than the second material strength. As a result, for example, the technical advantage is achieved that a harder area with better stability properties and a softer area with better sealing properties arises.

In a further advantageous embodiment of the method, the second tool area continuously merges into the first tool area. As a result, for example, the technical advantage is achieved that a sealing geometry can be produced with a continuous and edgeless transition.

In a further advantageous embodiment of the method, a distance of the second tool region from the semifinished product increases along the length of the semifinished product. As a result, for example, the technical advantage is achieved that the semifinished product is increasingly deformed and thereby solidified.

In a further advantageous embodiment of the method, the first tool area and the second tool area are formed in an annular recess of the tool. As a result, for example, the technical advantage is achieved that a high strength of the tool is achieved.

In a further advantageous embodiment of the method, the tool comprises a projecting insert section for insertion into an opening of the semifinished product. As a result, for example, the technical advantage is achieved that an accurate positioning and centering of the tool is made possible.

In a further advantageous embodiment of the method, the method comprises the step of heating the semifinished product before insertion into the tool. As a result, for example, the technical advantage is achieved that the semifinished product can be easily deformed.

In a further advantageous embodiment of the method, the method comprises the step of cooling the semifinished product after a massive forming by means of the tool. As a result, for example, the technical advantage is achieved that the semifinished product can be cured by means of a quench.

In a further advantageous embodiment of the method, the massive forming is a cold forming. As a result, the technical advantage is achieved, for example, that increases during a plastic deformation, the dislocation density in the metal.

According to a second aspect of the invention, the object is achieved by a fluid line with a sealing geometry, which is produced by the method according to the first aspect.

As a result, for example, the corresponding technical advantages as achieved by the respective method.

Embodiments of the invention are illustrated in the drawings and will be described in more detail below.

Show it:

1 a cross-sectional view of a semifinished product with a tool;

2 a cross-sectional view of a fluid conduit with a sealing geometry;

3 a block diagram for the preparation of the fluid line; and

4 a diagram with a stress-strain curve.

1 shows a cross-sectional view of a semifinished product 103 with a tool 105 , A spherical sealing area of a later sealing geometry of a fluid line which is to be connected to a bolting partner, is before a massive deformation of the semifinished product 103 shaped so that this area a processing contour 109 that is that of the tool 105 equivalent. The processing contour 109 is by a rounding of a pipe end 111 educated. The semi-finished product 103 For example, is a blank and formed of a metallic material.

The processing contour 109 For example, by means of a separating method at the pipe end 111 of the semi-finished product 103 be applied. The processing contour 109 is almost identical to the sealing ball contour of the later fluid line. The separating process may be a machining process that uses a patterned cutting edge, such as turning, milling, or reaming, or may be done with shape-free knit media such as, for example, grinding, thermal cutting, or eroding. Advantageously, the application of the spherical geometry of the processing contour 109 in a turning process.

In this case, with a form cutting the desired processing contour 109 on the semi-finished product 103 be applied or the rotary tool travels a path whose course the spherical processing contour 109 from the semifinished product 103 cutting out.

The advantage is achieved that no rotational depths in the longitudinal direction of the semifinished product 103 be introduced into the surface, which may affect the tightness in the subsequent sealing geometry.

The tool 105 for massive forming of the semifinished product 103 includes a first tool area 107-1 whose contour is the processing contour 109 of the semi-finished product 103 corresponds and a second tool area 107-2 whose contour is from the processing contour 109 of the semi-finished product 103 differs. After inserting the semi-finished product 103 with the prefabricated processing contour 109 in the tool 105 the sealing geometry of the Fluid line by a massive deformation of the semifinished product 103 educated.

In the case of massive forming is in the die of the tool 105 formed the final contour of the sealing geometry of the finished fluid line. Will the semi-finished product 103 introduced into the die, sets at the beginning of the massive forming a geometry section of the processing contour 109 to the identical contour of the first tool area 107-1 and is positively supported. In the massive forming of the semi-finished product 103 Thus occurs at this point only a small deformation of the semifinished product 103 on. The spherical sealing area of the sealing geometry of the later fluid line is hardly formed at this point by the massive forming.

For metals, the material is generally solidified by the deformation. However, because the surface of the sealing portion due to the mold support in the tool area 107-1 is not or only slightly deformed, increases the strength of the semifinished product 103 not or only to a small extent. In contrast, finds in the tool area 107-2 whose contour is from the processing contour 109 of the semi-finished product 103 deviates, a stronger deformation of the semifinished product 103 held during massive forming. The massive forming therefore produces a sealing geometry of the fluid line which comprises a first region with a low material strength and good sealing properties and a second region with a high material strength and good strength properties.

The second tool area 107-2 goes continuously into the first tool area 107-1 over, so that the sealing geometry can be generated smoothly and continuously. The distance of the second tool area 107-2 to the surface of the semifinished product 103 increases along the length of the semifinished product 103 starting from the pipe end 111 , Both the adjoining tool area 107-1 as well as the different tool area 107-2 are in an annular recess 113 of the tool 105 educated. In the middle of the annular recess 113 is an above application section 115 for insertion into an opening 117 of the semi-finished product 103 formed, which facilitates centering of the tool.

2 shows a cross-sectional view of the manufactured fluid line 100 with a sealing cone as sealing geometry 101 , The fluid line 100 is usually designed as a ball-and-cone connection to compensate for position variations. The sealing geometry 101 indicates an area due to the massive forming 101-1 with a lower material strength and a second area 101-2 with a higher material strength. The sealing area 101-1 has the same rounding as the processing contour 109 of the semi-finished product 103 ,

3 shows a block diagram for the preparation of the fluid line 100 , In step S100, the area becomes 101-1 the fluid line 100 , Which represents the actual connection and allows the sealing function, by means of a cutting process machined from the semifinished product 103 cut out. This creates the processing contour 109 of the semi-finished product 103 , Possible impact marks, scratches, defects or other defects that are on the surface of the semi-finished product 103 are in this process step of the semi-finished product 103 separated. In the manufacture of the fluid line 100 thus defects are removed, which are on the surface of the semifinished product 103 are located.

This results in the sealing surface of the later fluid line 100 no more surface irregularities. When joining a connection with such surface irregularities, insufficient sealing tape could form in the region of the defect so that the required surface pressure, which is needed to seal the connection, is not achieved. The connection would be faulty so that medium could leak out of the connection. By the separation process, the fluid line 100 However, a higher fault tolerance against defects or surface effects of the semifinished product 103 as starting material.

In step S101, the semi-finished product 103 with the prefabricated processing contour 109 in the tool 105 with the first tool area 107-1 whose contour is the processing contour 109 of the semi-finished product 103 corresponds to the second tool area 107-2 inserted, whose contour of the processing contour 109 of the semi-finished product 103 differs.

In step S102, the semi-finished product 103 by means of the tool 105 Massivungeformt to the sealing geometry 101 the fluid line 100 with the first material strength in the first tool area 107-1 and the second material strength in the second tool region 107-2 manufacture. As the area 101-1 the sealing geometry 101 already in the prefabricated semi-finished product 103 is present, this part of the sealing geometry 101 only slightly deformed by the massive forming. Deformations at this point of the sealing geometry are thereby prevented. The surface of the area 101-1 the fluid line 100 is softer and attaches better in the connection case to the geometry of the sealing partner.

During screwing the fluid line 100 in a motor vehicle, under the action of the biasing force applied during screwing, the area becomes flat 101-1 and forms a sealing surface by the contour conforms flat to the connection partner. This shows the connection of the fluid line 100 a higher process reliability in the screw connection and a higher fault tolerance against faulty connection partners.

In contrast, the area arises 101-1 the sealing geometry 101 during massive forming, by allowing the material into the tool area 107-2 is pressed and thereby deformed greatly. Because the massive forming necessary for the production of the sealing geometry 101 is performed, has no effect on the surface hardness of the sealing head, with a higher degree of deformation, a higher strain hardening in the range 101-2 the sealing geometry 101 be achieved.

It can thus be a higher-strength fluid line 100 can be produced without negatively influencing the sealing behavior at a sealing point. Therefore, it is possible to mitigate the trade-off between high strength of the molding and a soft sealing surface. It is also possible, firmer fluid lines 100 manufacture, which show higher resistance to setting the screw, but ensure a good seal due to the low surface strength of the sealing point.

4 shows a diagram with a stress-strain curve 119 before a plastic deformation of the semifinished product 103 and a stress-strain curve 121 after a plastic deformation of the semifinished product 103 , In the diagram, the stress σ is plotted against the strain ε of the material. In a linear-elastic range 123 of the material is Hooke's law, so that the strain ε is proportional to the stress σ. Plastic deformation increases the elastic limit by Re1-Re2 above σ1, so that a strain hardening of the semifinished product 103 arises.

All of the features explained and shown in connection with individual embodiments of the invention may be provided in different combinations in the article according to the invention in order to simultaneously realize their advantageous effects.

The scope of the present invention is given by the claims and is not limited by the features illustrated in the specification or shown in the figures.

LIST OF REFERENCE NUMBERS

100

 fluid line

101

 sealing geometry

101-1

 Area

101-2

 Area

103

 Workpiece

105

 Tool

107-1

 tool area

107-2

 tool area

109

 processing contour

111

 pipe end

113

 recess

115

 insert portion

117

 opening

119

 Stress-strain curve

121

 Stress-strain curve

123

 linear-elastic range

S101

 edit out

S101

 insert

S102

 massive forming

Claims (15)

Method for producing a fluid line ( 100 ) with a sealing geometry ( 101 ), a first area ( 101-1 ) with a first material strength and a second region ( 101-2 ) comprising a second material strength, from a semifinished product ( 103 ), with the steps: inserting (S101) the semi-finished product ( 103 ) into a tool ( 105 ) with a first tool area ( 107-1 ) whose contour of a processing contour ( 109 ) of the semifinished product ( 103 ) and a second tool area ( 107-2 ) whose contour differs from the processing contour ( 109 ) of the semifinished product ( 103 ) deviates; and massive forming (S102) of the semifinished product ( 103 ) by means of the tool ( 105 ) for producing the sealing geometry ( 101 ) with the first material strength in the first tool area ( 107-1 ) and the second material strength in the second tool region ( 107-2 ). The method of claim 1, wherein the method comprises the step of cutting out (S100) the processing contour (S100) 109 ) of the semifinished product ( 103 ) by means of a separation process.  The method of claim 2, wherein the separation process is a patterned edge cutting process. Method according to one of the preceding claims, wherein the semifinished product ( 103 ) a metal pipe with a pipe end ( 111 ). Method according to claim 4, wherein the processing contour ( 109 ) of the pipe end ( 111 ) of the contour of the first tool area ( 107-1 ) corresponds. Method according to claim 5, wherein the processing contour ( 109 ) of the pipe end ( 111 ) by a rounded edge of the pipe end ( 111 ) whose radius of curvature corresponds to a radius of curvature of the first tool area (FIG. 107-1 ) corresponds.  Method according to one of the preceding claims, wherein the first material strength is less than the second material strength. Method according to one of the preceding claims, wherein the second tool area ( 107-2 ) continuously into the first tool area ( 107-1 ) passes over. Method according to one of the preceding claims, wherein a distance of the second tool area ( 107-2 ) of the semifinished product ( 103 ) along the length of the semifinished product ( 103 ). Method according to one of the preceding claims, wherein the first tool area ( 107-1 ) and the second tool area ( 107-2 ) in an annular recess ( 113 ) of the tool ( 105 ) are formed. Method according to one of the preceding claims, wherein the tool ( 105 ) a protruding insert section ( 115 ) for insertion into an opening ( 117 ) of the semifinished product ( 103 ). Method according to one of the preceding claims, wherein the method comprises the step of heating the semifinished product ( 103 ) before insertion into the tool ( 105 ). Method according to one of the preceding claims, wherein the method comprises the step of cooling the semifinished product ( 103 ) after a massive forming by means of the tool ( 105 ).  A method according to any one of the preceding claims, wherein the massive forming (S102) is cold working. Fluid line ( 100 ) with a sealing geometry ( 101 ) produced by the method according to any one of claims 1 to 14.

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