U.S. patent application number 10/520354 was filed with the patent office on 2006-07-13 for method and device for securing components on peripherally closed hollow profiles.
This patent application is currently assigned to DaimlerChrysler AG. Invention is credited to Stefan Schwarz.
Application Number | 20060150389 10/520354 |
Document ID | / |
Family ID | 29761670 |
Filed Date | 2006-07-13 |
United States Patent
Application |
20060150389 |
Kind Code |
A1 |
Schwarz; Stefan |
July 13, 2006 |
Method and device for securing components on peripherally closed
hollow profiles
Abstract
The invention relates to a method for fixing components (2) to
peripherally closed hollow profiles (3). Walls (4,5) of the
component (2) and the hollow profile (3) are connected to each
other in a positive fit. In order to fix the component (2) to the
hollow profile (3) in a simple manner, independent or position, the
walls (4,5) to be joined are placed in an adjacent position and are
locally impinged upon by external pressure such that the walls
(4,5) a repressed inside (12) the hollow profile (3) and a
double-walled indentation (10) is formed, wherein the walls (4,5)
are clamped against each other.
Inventors: |
Schwarz; Stefan; (Lunen,
DE) |
Correspondence
Address: |
CROWELL & MORING LLP;INTELLECTUAL PROPERTY GROUP
P.O. BOX 14300
WASHINGTON
DC
20044-4300
US
|
Assignee: |
DaimlerChrysler AG
Epplestrasse 225
Stuttgart
DE
70567
|
Family ID: |
29761670 |
Appl. No.: |
10/520354 |
Filed: |
May 22, 2003 |
PCT Filed: |
May 22, 2003 |
PCT NO: |
PCT/EP03/05350 |
371 Date: |
August 11, 2005 |
Current U.S.
Class: |
29/521 ;
29/283.5; 29/522.1 |
Current CPC
Class: |
Y10T 29/53996 20150115;
B21D 26/051 20130101; B21D 39/031 20130101; B21D 26/035 20130101;
Y10T 29/49936 20150115; Y10T 29/49938 20150115 |
Class at
Publication: |
029/521 ;
029/522.1; 029/283.5 |
International
Class: |
B21D 39/00 20060101
B21D039/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 5, 2002 |
DE |
102 30 284.7 |
Claims
1-25. (canceled)
26. A method for fastening a component to a peripherally closed
hollow profile, the method comprising the steps of: applying an
external pressure to an area of walls of the component and hollow
profile, so that the walls of the component and hollow profile in
the area are clamped to one another and are forced into the
interior of the hollow profile.
27. The method according to claim 26, wherein the step of applying
the external pressure includes applying the external pressure
mechanically using a plunger.
28. The method according to claim 26, wherein the step of applying
the external pressure includes applying the external pressure using
a pressurized fluid medium.
29. The method according to claim 26, comprising fastening the
component to the hollow profile with the wall of the component
inside of the hollow profile wall.
30. The method according to claim 26, comprising fastening the
component to the hollow profile with the wall of the component
outside of the hollow profile wall.
31. The method according to claim 26, wherein the component is a
second hollow profile and is fitted together with the first hollow
profile before the component is fastened to the first hollow
profile.
32. The method according to claim 26, wherein the component has a
flange that is fastened to the hollow profile.
33. The method according to claim 26, comprising forcing the area
of the walls into a recess formed on the circumference of a mandrel
so that the wall of the component or of the hollow profile is in
contact with a wall of the recess in a contour-matching manner.
34. The method according to claim 26, comprising forming undercuts
by applying a counter-pressure from the interior of the hollow
profile on the walls.
35. The method according to claim 34, comprising generating the
counter-pressure by an internal high fluid pressure in the hollow
profile.
36. The method according to claim 34, wherein the step of forming
undercuts including forming the undercuts by a radial expansion of
a spreadable end of a plunger.
37. The method according to claim 26, wherein, before the walls of
the component and hollow profile are fastened to one another, at
least one of the walls is applied with an adhesive, and wherein,
after the formation of a double-walled indentation, the
adhesiveness of the adhesive is activated by heat treatment.
38. The method according to claim 26, wherein, before the walls of
the component and hollow profile are fastened to one another, at
least one of the walls is coated with solder, and wherein, after
the formation of a double-walled indentation, the component and the
hollow profile are soldered together by heat treatment of the
solder.
39. The method according to claim 26, wherein the hollow profile is
formed from two superimposed skelps by internal high fluid
pressure, and wherein the pressing is performed during or after the
internal high pressure forming of the skelps.
40. Apparatus for fastening a component to a peripherally closed
hollow profile, comprising: a receiver in which the hollow profile
and the component are held such that walls of the hollow profile
and of the component are in contact with one another; a device for
applying a pressure medium to clamp the walls together and to force
the walls into the interior of the hollow profile with a formation
of a double-walled indentation, wherein the pressure medium is
disposed outside of the hollow profile. a die within the hollow
profile, wherein the pressure medium pushes the walls into the die
to form a double-walled indentation for the clamp- fastening of the
component to the hollow profile.
41. The apparatus according to claim 40, wherein the pressure
medium is a fluid pressure.
42. The apparatus according to claim 40, wherein the pressure
medium is a plunger.
43. The apparatus according to claim 40, wherein the receiver is an
internal high pressure forming tool.
44. The apparatus according to claim 40, wherein the die is a
mandrel which can be pushed into the hollow profile and has a
recess, into which the walls can be pushed by the pressure
medium.
45. The apparatus according to claim 44, wherein the mandrel is an
axial plunger forming an internal high pressure forming tool.
46. The apparatus according to claim 45, wherein the indentation
has undercut surfaces.
47. The apparatus according to claim 46, wherein the undercut
surfaces are in the form of a dovetail.
48. The apparatus according to claim 44, wherein the mandrel has an
axial fluid passage from which a radial passage branches, which
radial passage opens in the indentation.
49. The apparatus according to claim 42, wherein the plunger can be
spread open at its end.
50. The apparatus according to claim 40, wherein the die is a
diaphragm or tubular bellows, which can be introduced into the
hollow profile and is supported internally during insertion.
Description
BACKGROUND AND SUMMARY OF THE INVENTION
[0001] The invention relates to a method for fastening components
to initially closed hollow profiles, and a device for that
purpose.
[0002] DE 196 19 626 C2 discloses a device in which hangers are
affixed to a hollow profile such that both the hanger and the
hollow profile are placed in engravings of a high internal pressure
forming tool and then the section is subjected to a high internal
fluid pressure. Under this pressure the material of the hollow
profile flows radially outward and at the location of the hanger it
flows conformingly around the surface of the hanger which has an
undercut shape so that an interlocking bond is established between
the hanger and the hollow profile. The described fastening of the
hanger to the hollow profile is possible, however, only within the
expanded area between the axial sealing and punches that close the
ends of the hollow profile. Furthermore, the flexibility of the
method is limited by the fact that the shape of the high internal
pressure forming tool permanently establishes the shape and
location of the bond, so that in the case of different requirements
as to the position and kind of the interlocking bond different
tools are necessary. The result is great expense and investment in
the device.
[0003] The invention is addressed to the task of improving a method
of that kind and a device also of that kind so that a secure
fastening of the component to the hollow profile is made possible
in a simple manner, regardless of the point of fastening.
[0004] The problem is solved according to the invention by the
invention described and claimed below.
[0005] Inasmuch as an external pressure is applied to the adjacent
walls of the hollow profile and hanger by means of a pressure
medium and thus they are forced inward into the interior of the
hollow profile thus forming a double-walled indentation, a clamping
of the walls is achieved which assures a secure fastening of the
hanger to the hollow profile. This indentation is possible axially
and radially at any point on the hollow profile and is freed of any
specific shapes of the receiver of the hollow profile and hanger,
so that not only the receiver but also the entire device can be
configured in a very simple manner. With the method of the
invention a simple possibility of fastening is offered that is
reliable and practical for hollow profiles that are to be fastened
together, which otherwise can not be fastened together in a
reliable manner, especially hollow profiles shaped by internal high
pressure with attachments or in some cases to other hollow profiles
made in the same manner.
[0006] Appropriate developments of the invention can be found in
the sub-claims; otherwise the invention is further explained below
with the aid of several embodiments represented in the drawings,
wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a lateral longitudinal fragmentary section of a
device of the invention with a plunger introduced into a hollow
profile and having a punch which can be inserted from the exterior
and can run on the walls of a hollow profile and component.
[0008] FIG. 2 is a fragmentary cross section of the device of FIG.
1 with the plunger in the piercing position with a mandrel of
undercut shape.
[0009] FIG. 3 shows an expandable plunger of a device according to
the invention in a lateral longitudinal cross section.
[0010] FIG. 4 shows a device according to the invention in a
lateral longitudinal cross section with a plunger in the piercing
phase and with a mandrel from FIG. 3 spread out in the piercing
position.
[0011] FIG. 5 shows in a lateral longitudinal section a device
according to the invention with a bipartite mandrel and a fluid
pressure medium for the inward forcing.
[0012] FIG. 6 shows in a lateral longitudinal section a device
according to the invention with a bipartite mandrel with pinching
action on the material of the walls to be joined.
[0013] FIG. 7 shows in a lateral longitudinal section a device
according to the invention with an elastic skin introduced into the
hollow profile.
DETAILED DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 shows a device for fastening a component 2 to an
initially closed hollow profile 3. The hollow profile 3 and the
component 2 are held in a receiver here not further shown, with
their walls 4 and 5 placed against one another. In this case it is
desirable for the assembly process and for a simplified
configuration of the receiver if the wall 5 of the component 2 is
matched to the contours of the wall 4 of the hollow profile 3. The
wall 5 of the flat component 2 is here formed by a flange
projecting at right angles. For assembly, a metal mandrel 6 of the
device 1 is inserted into the hollow profile 3 and on the
circumference of the mandrel a gap 7 open in the direction of
insertion is formed. The axial opening of the gap 7 assures the
easy withdrawal of the mandrel 6 after the assembly is completed.
This gap 7 comes to rest at the location of the walls 4 and 5 which
are to be assembled. Then a plunger 8 forming the pressure medium
arranged according to the invention locally outside of the hollow
profile 3, opposite the gap 7, is driven by a hydraulic, pneumatic,
electric motor, electromagnetic or mechanical drive connected to
the back of the plunger 8 in the direction of the arrow directly
against the wall 5 and indirectly against the adjacent wall 4. As
the movement continues, the massive cylindrical plunger 8 pushes
the walls 4 and 5 into the gap 7, which thereby forms a molded
image of the mandrel 6 serving as a die.
[0015] Although in this case a certain interlocking clamping
together of the walls 4 and 5 is achieved, it is desirable if the
walls 4 and 5 are forced by the plunger 8 into the gap 7 such that
they are forced against the wall 9 of the gap in order to improve
the clamping in the manner of a press fit (FIG. 2) and in addition
to the shape interlock to achieve a friction lock which holds the
walls 4 and 5 securely, i.e., for release with difficulty, against
one another. In this case the wall of the hollow profile 3 that is
nearest the gap conforms to the shape of the gap wall 9. The
double-walled indentation 10 formed by the pressing action can have
substantially straight mantle lines. The gap 7, however, can also
be formed with undercut surfaces, especially in the manner of a
dovetail 11. Thus, on account of the counterpressure exercised by
the gap wall 9 outwardly from the interior 12 of the hollow profile
3, undercuts 13 and 14 are formed on the walls 4 and 5 by the
forcing in and compression of the walls 4 and 5 into the gap 7. For
that reason the walls 5 of component 2 are anchored against radial
removal in the wall 4 of the hollow profile. In the present
embodiment the component 2 is fastened with its wall 5 outside on
the hollow profile wall 4. However, it is also possible within the
scope of the invention in the same way to position the wall 5 of
component 2 inside of the hollow profile 3 and fasten it on the
inside of its wall 4. The mandrel 6 must then only be reduced in
its diameter. With the above variant it is possible in a simple
manner to fasten the component 2 also to the circumference of the
ends of the hollow profile 3--including, in the extreme case, the
outer edge of the hollow profile 3--which is not possible or
possibly only with difficulty with the method described in the
cited state of the art. It is furthermore conceivable, instead of
the cylindrical shape of the plunger 8 to use a plunger
configuration in which the tip of the plunger penetrating into the
interior 12 of the hollow profile 3 is of spatulate shape. If the
plunger 8 is now forced with the walls 4 and 5 into the gap 7, the
walls do not entirely fill out the shape of the gap 7 with the
plunger 8 in its axial end position. By rotating the plunger 8 by
90 degrees the wall material of walls 4 and 5 is forced into the
gap 7 such that it is completely filled up and the walls 4 and 5
are made to conform to the shape of the gap. Then the plunger 8 is
turned back 90 degrees and can then be easily removed from the gap
7 and the indentation 10 in the wall. Due to the complete
conformity of the walls 4, 5 in the gap 7 the desired undercut is
optimally shaped to match it, so that the clamping together of the
walls 4 and 5 is improved and thus their lock onto one another is
improved.
[0016] In another embodiment according to FIGS. 3 and 4, a variant
of the invention that is advantageous due to their simple
configuration is illustrated. The receiver in this case forms a
high internal pressure forming tool 15 into which one or more
plungers 8 spaced axially apart from one another are integrated,
which are displaceable in guides 16 as indicated by the vertical
double arrow. It is indeed conceivable for the plunger 8 to force
the walls 4 and 5 into the interior 12 of the hollow profile 3,
operate against atmospheric pressure in the hollow profile 3, after
which a high fluidic internal pressure is created (FIG. 4, 1).
[0017] It is a more economic process and shortens the cycling time,
however, if the hollow profile 3 is under high internal pressure
while the plunger 8 is forcing the walls 4 and 5 inward. The
counter pressure which would be created in the foregoing example
against the plunger 8 and the walls 4 and 5 by contact with the
notch wall 9 for the forming operation is here provided by the high
internal pressure. Or account of the forces of the internal high
pressure and the plunger 8 acting on the face 17 of the
indentation, a sideways displacement of the material of the hollow
profile and component, rendered fluid by the high internal
pressure, takes place. The end face 17 is made thinner as a result,
leading to an accumulation of the hollow profile and component
material in the edge area 18 of the end face 17. This has the
effect that all around in this area 18 undercut areas form in the
indentation 10, so that, in a manner improved beyond the preceding
embodiment, the result is a junction similar to a through-joint,
which is inseparable in any direction (axial and radial).
[0018] A more intense formation of the undercut surfaces is
achieved by using a plunger 8 according to FIG. 3, which can be
spread open at its end 19 facing the hollow profile. This end has a
central axial bore 20 which tapers toward the end 19 facing the
hollow profile and ends there. Depending on the elasticity of its
material in the area of the taper, the plunger 8 is provided at a
place on its circumference with an axial slot 21 to provide for the
outward expansion of the end 19, which scores the bore 20 over its
entire length. In the bore 20 a pin 22 is guided for the
displacement indicated by the double arrow; the pin 22 has at its
bottom end 23 wedging surfaces 24 by means of which, when it is
driven downwardly through the taper in the bore 20, it comes in
contact with the bore walls and drives apart the slotted sectors of
the end 19. In this manner, as indicated by the two arrows, when
the plunger 8 reaches the end in the area of the face 27, both the
hollow profile and the material of the indentation 10 are forced
radially apart causing the undercut surfaces to be enlarged (FIG.
4, II). In this way the match between the walls 4 and 5 and thus
their mating with one another is improved. After the desired
undercut's formation has been achieved, the pin 22 is withdrawn,
after which the end 19 returns by its elasticity to its starting
position, so that the plunger 8 can be removed from the indentation
10.
[0019] In an alternative to the two embodiments described, in the
case where the receiver is in the form of a high internal pressure
shaping tool 15, a mandrel 6 can be driven into the hollow profile
3. In this case the mandrel 6, in a dual function, can
advantageously form both the matrix for the plunger 8 and the axial
sealing plunger of the tool 15.
[0020] It has been assumed up to now that the forcing means is the
plunger 8. In another embodiment the forcing means, however, can
also be a fluid pressure column 25, as seen, for example, in FIG.
5. For this purpose a passage 27 is formed in the receiver, which
in this case is likewise an internal high pressure forming tool 26,
and is connected outside of the receiver to a pressure generator,
and terminates at the walls 4 and 5 in the receiver. The passage 27
is sealed in the marginal area 28 of the receiver by at least one
sealing ring 30 beside its opening 29. The pressure column 25
causes virtually no wear on the device 1 and has the additional
advantage that the pressure on the walls 4 and 5 can be adjusted
very finely and quickly and can be continually adapted to the
desired sequence of the pressure injection process. In the present
embodiment according to FIG. 5, a mandrel 31 is introduced with
little free play into the hollow profile 3. In order to form
undercut surfaces all the way around the edge 19 of the end face 17
in the indentation, the recess 32 of the mandrel 31 is
trough-shaped --i.e., continuous all around--with a dovetail-like
cross section. With the pressure column 25 the walls 4 and 5 are
forced into the recess 32 until they contact the wall 33 of the
recess. The flexibility of the hydraulic fluid is an advantage to
the accurate mating of the walls 4 and 5 with the shape of the
indentation, because in contrast to the limited ability of a
rigidly shaped plunger, it is able to follow the progress of the
impression in all directions. The pressure is applied, therefore,
directly by the driven hydraulic fluid.
[0021] After the shaping of the indentation 10, in order to remove
the mandrel 31 from the forming tool 26 with the release of the
undercut surfaces, the mandrel 31 is divided into two parts 34 and
35 along its length. Each part 34 and 35 has a section of the
recess 32 which is formed at the face 36 of each part 34 and 35, so
that when the two ends 36 are in contact with one another the whole
recess 32 is the result. To assure that the two parts 34 and 35
will be together during the impressing process it is desirable to
screw the two parts 34 and 35 together. After the indentation 10
has been completed, the screw fastening is released and the two
parts 34 and 35 are drawn in opposite directions out of the hollow
profile 3 and the forming tool 26. Alternatively, parts 34 and 35
can be driven by hydraulic cylinders and held securely in the end
position within the hollow profile 3. This certainly shortens the
cycle in comparison with screw fastening, but requires expensive
equipment. Furthermore, it is alternatively conceivable to hold the
two paarts 34 and 35 together in a simple manner with a clamping
device, which can be released quickly if necessary, after they
reach the end position against one another.
[0022] To expedite the formation of the undercut surfaces, and for
improvement in the uniform filling out of the radii of the recess
32, and thus to achieve optimum mating between walls 4 and 5, the
mandrel 31 has an axial fluid passage 37 from which a radial
passage 38 branches off, which leads into the recess 32 at its
bottom 39. Passages 37 and 38 can be only in one of the parts 34 or
35, or--as shown in FIG. 5--pass through part 34 at passage 37 and
terminate in part 35, and be formed as regards passage 38 by an
opening at both ends 35 of parts 34 and 35. By feeding a
high-pressure fluid through passages 37 and 38 the walls 4 and 5
are made to flow, so that, being driven by the fluid pressure
column 25 into the corner areas of the recess 32, they can conform
to the walls of the corner areas of recess 32. The variant
described can be used, on account of its localized fluid pressure,
also wherever some other deformation of the hollow profile 3 is not
desired.
[0023] Another advantageous variant is shown in the embodiment seen
in FIG. 6. Unlike the variant in FIG. 5, the recess wall 33 of
parts 34 and 35 have undercut surfaces 41 as seen in longitudinal
section. Instead of the fluid pressure column 25, a hollow or solid
plunger can be used, as also in the case of the variant in FIG. 5.
In order to press the wall material of walls 4, 5 into the recess
32 such that it will come into conforming contact with the undercut
surfaces 41, first an indentation of shallow depth is produced by
the fluid pressure column 25 or by the plunger 8 in the two walls 4
and 5. The two parts 34 and 35 have their faces 36 still spaced
apart from one another at this time. After the indentation is
produced, the two parts 34 and 35 are driven together in the
directions of the arrows, while the wedge-shaped closing edges 42
of parts 34 and 35 drive the material of walls 4 and 5 and pinch
them. In this pinching action the wall material applies itself
simply to the undercut surfaces 41 until the two faces 36 come in
contact with one another. To allow this to be accomplished surely,
so that no wall material gets on the faces 36, care must be taken
to see that either the indentation is small enough when parts 34
and 35 begin to move toward one another, or the bottom 39 of the
recess 32 must be at least so deep that the wall material of the
indentation 10 will not come in contact with the bottom 39 until
the faces 36 of parts 34 and 35 are in contact with one another.
The described variant method has the advantage that, for the
formation of the indentation 10, wall material is fed axially by
the parts .34 and 35, so that harmful effects are prevented.
Furthermore, due to the active axial action of parts 34 and 35 on
the wall material, the variant is a method as to how a virtually
complete mating together of two walls 4 and 5 with undercut
surfaces 41 can be achieved.
[0024] In an additional advantageous embodiment according to FIG.
7, the component 2 can be in the form of a hollow profile which is
assembled together before it is fastened to the hollow profile 3. A
tubular elastic bellows 40 can be introduced, as shown in this
embodiment in FIG. 7, into the hollow profile 3 which here is
internal, and it supports the hollow profile 3 while the plunger 8
thrusts internally, while within the bellows 40 a fluidic high
internal pressure is applied, which on the one hand expands the
hollow profile 3 during the procedure of pressing with the plunger
8, while within the bellows 40 a fluidic high pressure is applied,
which expands the hollow profile 3 together with the tubular
component 2, and in cooperation with the plunger 8, as already
described in the embodiment in FIGS. 3 and 4, forms the undercut
surfaces of the indentation 10. The bellows 40 thus forms part of a
matrix which additionally consists of the pressure medium itself,
into which the walls 4 and 5 can be pressed. With the bellows 40 it
is brought about that the hollow profile 3 is not wetted by the
pressure medium, which is desirable for easily corroded materials.
Furthermore, the bellows 40 prevents hydraulic fluid from leaking
out uncontrolled in the event of any kind of crazing or cracking in
the indentation 10, and provide for any unwanted loss of pressure
which would undermine any reliable shaping of undercut surfaces.
Instead of the bellows 40 the device 1 can contain a diaphragm
fastened, for example, to the axial plunger.
[0025] For additional strengthening of the bond between the walls 4
and 5, they can be brushed or coated with an adhesive before they
are brought together, the tackiness of the adhesive being
activated, preferably by heat treatment after the double-walled
indentation is formed. As an alternative the walls 4 and 5 can also
be coated with a solder, and after the indentation 10 is formed
they can be soldered together by heat treating the solder and the
component 2 and hollow profile 3 in an oven.
[0026] The hollow profile 3 itself can be made from pipe skelp
rolled and then welded along the seam. In like manner, extruded or
rolled shapes can be considered. However, two superimposed skelps
can be shaped by means of internal high fluidic pressure, and the
impression can be performed in an economic manner during or after
formation by internal high fluidic pressure. The hollow profile 3
can have a circular cross section like the tubular raw material or
it can have other cross-sectional shapes which can be obtained by
flattening, bending and pressing or the like.
[0027] Otherwise, the indentation 10 can also run like an annular
groove around the component 2 and the hollow profile 3. The
compression means can be the pressure column 25 as well as a
segmented annular die surrounding component 2 as well as hollow
profile 3.
[0028] Moreover, an additional advantage of the embodiments in
FIGS. 4 and 7 should be mentioned at this point. As a result of the
high internal pressure, when the walls 4 and 5 are forced in by the
plunger 8 or the pressure column 25, due to the resistance offered
by the high internal pressure, no sinking deformations with great
bending radii are formed in the marginal area adjacent the
indentation 10 to the detriment of the dimensional stability of the
external shape of the hollow profile 3. Thus, the shape of the
contour remains unaffected by the forcing inward, which among other
things satisfy requirements as to the external appearance of the
assembly of the hollow profile 3 to the component 2.
* * * * *