U.S. patent application number 09/799075 was filed with the patent office on 2001-10-04 for process and apparatus for mechanically joining metallic components.
Invention is credited to Hahn, Ortwin, Schulte, Volker.
Application Number | 20010025518 09/799075 |
Document ID | / |
Family ID | 7633344 |
Filed Date | 2001-10-04 |
United States Patent
Application |
20010025518 |
Kind Code |
A1 |
Hahn, Ortwin ; et
al. |
October 4, 2001 |
Process and apparatus for mechanically joining metallic
components
Abstract
A process for mechanically joining plies of thin metallic
components lying on one another, and apparatus for its
implementation, involves an impulse-wave conductor (9, 25, 31-35)
having first and second substantially straight
impulse-wave-conductor portions (19, 20, 32, 33) which are arranged
at an angle to one another along which impulse waves are
transmitted to a stamp (7) to be driven into a component to be
joined by impulse force. The impulse waves are redirected between
the first and second substantially straight impulse-wave-conductor
portions by a structure of an intermediate angled portion (21, 31)
located between, the first and second substantially straight
impulse-wave-conductor portions.
Inventors: |
Hahn, Ortwin; (Paderborn,
DE) ; Schulte, Volker; (Olsberg, DE) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Family ID: |
7633344 |
Appl. No.: |
09/799075 |
Filed: |
March 6, 2001 |
Current U.S.
Class: |
72/29.2 ;
72/379.2; 72/407; 72/48 |
Current CPC
Class: |
B21J 15/10 20130101;
B21J 15/12 20130101; B21J 15/025 20130101; B21D 39/031
20130101 |
Class at
Publication: |
72/29.2 ; 72/48;
72/379.2; 72/407 |
International
Class: |
B21D 031/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 6, 2000 |
DE |
(6) 100 10 340.5 |
Claims
I claim:
1. Process for mechanically joining plies of thin metallic
components lying on one another, including providing a joining
tool, wherein a stamp of the joining tool is driven into a
component to be joined by impulse force with the impulse force
being transmitted to the stamp as impulse waves via an impulse-wave
conductor (9, 25) of the joining tool; wherein, the impulse-wave
conductor is provided to have first and second substantially
straight impulse-wave-conductor portions (19, 20) which are
arranged at an angle to one another along which the impulse waves
are transmitted to the stamp, wherein the impulse waves are
transmitted between the first and second substantially straight
impulse-wave-conductor portions (19, 20) by redirecting them with
an intermediate angled portion (21) formed as one piece with, and
between, the first and second substantially straight
impulse-wave-conductor portions (19, 20).
2. A tong shaped joining tool for mechanically joining two thin
metallic components lying on one another, said joining tool
including: a stamp for being driven into at least one of the
components by impulse force acting on the stamp; an impulse-wave
conductor (9) attached to the stamp for conducting impulse force to
the stamp as a compression wave, wherein the impulse-wave conductor
(9) includes as one piece a bent intermediate portion (21) between
two substantially-straight legs (19, 20), with the intermediate
portion (21) extending in a largest possible arc for conducting
said compression wave between said two substantially-straight legs
(19, 20), via the intermediate portion (21).
3. A tong shaped joining tool for mechanically joining two thin
metallic components lying on one another, said joining tool
including: a stamp for being driven into at least one of the
components by impulse force acting on the stamp; an impulse-wave
conductor (25) attached to the stamp for conducting impulse force
to the stamp as a compression wave, wherein the impulse-wave
conductor (25) includes as one piece two straight legs (19, 20) and
an angled portion, with an outer angled edge of the angled portion
forming a beveled flat-area surface (22), with the flat area
surface being of a such size and extending at such an angle that
projections thereof, toward each free end of the straight legs (19,
20) of the impulse-wave conductor, correspond to perpendicular
cross-sectional cuts of the straight legs.
4. A joining tool as in claim 3 wherein is further included a mass
body (23) pressed against the flat-area surface (22) by a spring
system (40), wherein a surface (24) of the mass body (23) lying
against the flat-area surface (22) is larger than the flat-area
surface (22) of the impulse-wave conductor (25) and extends beyond
the flat-area surface (22) on all sides, and wherein a natural
frequency of a spring-mass-system is half so great as an impulse
wave frequency.
5. A tong shaped joining tool for mechanically joining two thin
metallic components lying on one another, said joining tool
including: a stamp (7) for being driven into at least one of the
components by impulse force acting on the stamp; an impulse-wave
conductor attached to the stamp for conducting impulse force to the
stamp as a compression wave, wherein the impulse-wave conductor
comprises first and second separate impulse-wave conductor parts
(32, 33) arranged at an angle to one another, with a separate
angled rebound body (31) positioned between the first and second
impulse-wave conductor parts (32, 33) and being pivotal about a
pivot point (34) lying between the impulse-wave conductor parts
(32, 33), with a first end (35) of the rebound body (31) lying
against an impulse-input-side of the first impulse-wave conductor
part (32) under a spring bias and with a second other leg end (36)
of the rebound body (31) being spaced from the second impulse-wave
conductor part (33) which has the stamp (7) coupled thereto.
6. The tong shaped joining tool of claim 5 wherein, a bias force of
a spring (37) creating the spring bias is chosen such that the
rebound body (31) is thereby caused to once again lie against the
first impulse-wave conductor part (32) after it swings out in time
for arrival of a next following impulse wave.
7. The tong shaped joining tool of claim 6 wherein, the rebound
body (31), upon its return swing, is made to lie quickly against
the first impulse-wave conductor part (32) by contact with an
elastic impact damper (38).
8. The process of claim 1 wherein, the impulse-wave conductor
provided is of a material which provides very little damping.
9. The process of claim 1 wherein, the substantially straight
impulse-wave-conductor portion (20) of the impulse-wave conductor
(9, 25) operating on the stamp (7) extends in a direction of a
length axis of the stamp (7).
10. The process of claim 1 wherein, is further included at least
one piezoelectric actuator (29, 30) for creating the impulse
wave.
11. The process of claim 1 wherein, is further provided a die plate
(8) toward which the stamp is driven, and wherein impulse waves are
conducted to the die plate by an impulse-wave conductor (10, 26)
which is substantially similar in form to the impulse-wave
conductor (9, 25) conducting impulse waves to the stamp (7).
12. The process of claim 11 wherein, the impulse-wave conductors
(9, 25) are formed by upper and lower tong arms.
13. The process of claim 11 wherein, the joining tool is tong
shaped and wherein upper and lower tong arms of the tong shaped
joining tool are hollow and wherein the impulse-wave conductors
(25, 26) are positioned therein.
14. The process of claim 13 wherein, a material for mounting the
impulse-wave conductor has a distinctively different sound
resistance than does the impulse-wave conductors.
15. The process of claim 1 wherein, the joining tool provided is in
the form of a tong structure that is structured in a general manner
of shears.
16. The process of claim 15 wherein, a rebound mass (17) is pressed
against the impulse-wave conductor (10, 26) at an outer end of the
lower tong arm (2) by a spring system (18, 28) for eliminating
impulse waves.
17. The process of claim 12 wherein, the impulse-wave conductors
(9, 10, 25, 26) are covered by a sound damping material.
18. The process of claim 1 wherein, an impulse-wave-creating
striking tool (14) is provided that is pressed against the
impulse-wave conductor (9, 25) for creating the impulse waves.
19. The process of claim 1 wherein, the joining tool has a portion
thereof touching a component to be joined outside of a joining area
that is coated with a vibration-dampening coating.
20. The process of claim 10 wherein, the lower tong arm which
supports the die plate (8) also has at least one piezoelectric
actuator (30) associated therewith which operates on the female
mold (8) in time with the actuator (29) operating on the stamp
(7).
21. The tong shaped joining tool of claim 5 wherein, the rebound
body (31) has two legs (35, 36) and has a body-sound-dampening
intermediate layer (39) between its two legs (35, 36).
22. Process for mechanically joining plies of thin metallic
components lying on one another, wherein a stamp of a joining tool
is driven into a component to be joined by impulses force with the
impulse force being transmitted to the stamp as impulse waves via
an impulse-wave conductor; wherein, the impulse-wave conductor
provided has first and second separate, substantially straight,
impulse-wave-conductor parts (32, 33) which are arranged at an
angle to one another along which the impulse waves are transmitted
to the stamp, wherein impulse waves are transmitted between the
first and second substantially straight impulse-wave-conductor
parts by redirecting them with a reciprocating rebound body (31)
for receiving a force from impulse waves in the first substantially
straight impulse-wave-conductor part (32) and redirecting the force
by impacting the second substantially straight
impulse-wave-conductor part (33).
Description
BACKGROUND OF THE INVENTION
[0001] This application claims a foreign priority based on German
application 100 10 340.5, filed Mar. 6, 2000, and the contents of
that application are incorporated by reference herein.
[0002] This invention concerns a process for mechanically joining
(for example, clinching and stamping together) two plies of thin
metallic components, such as sheet metal, lying on one another, and
an apparatus to carry this out, involving a stamp of a joining tool
being driven into a component to be joined by impulse force with
the impulse force being transmitted to the stamp as impulse waves
via an impulse-wave conductor. Examples of such processes and
apparatus are disclosed in German patent document DE 197 77 267 C2
and European patent document EP 0 890 397 A1.
[0003] In both of these publications a striking tool having an
impulse-creating plunger, an impulse-wave conductor and a stamp are
arranged in a row along a vertical axis. Thus, a rather tall
structure results, so that joining processes to be carried out by
this apparatus cannot be done in operation areas that have limited
space, although they are particularly well suited therefor.
[0004] It is an object of this invention to provide a joining
process involving a stamp of a joining tool being driven into a
component to be joined by impulse force with the impulse force
being transmitted to the stamp as impulse waves via an impulse-wave
conductor, and a joining tool for carrying out this process, that
makes possible a significantly shorter profile for that part for
the tool containing the stamp, the impulse-wave conductor and the
striking tool.
SUMMARY OF THE INVENTION
[0005] According to principles of this invention, a joining process
involves providing an impulse-wave conductor with first and second
substantially straight impulse-wave-conductor portions (straight
legs) which are arranged at an angle to one another and
transmitting impulse waves between the first and second
substantially straight impulse-wave-conductor portions by
redirecting them with an intermediate angled portion formed as one
piece with, and between, the first and second substantially
straight impulse-wave-conductor portions or with a reciprocating
rebound body for receiving a force from impulse waves in the first
substantially straight impulse-wave-conductor portion and
redirecting them by impacting the second substantially straight
impulse-wave-conductor portion.
[0006] An apparatus for carrying out this process has one of: a
bowed intermediate portion made as one piece with, and being
positioned between, the two substantially-straight legs, with the
intermediate portion extending in a largest possible arc; an angled
intermediate portion having a beveled flat-area surface, with the
flat-area surface being of such a size, and extending at such an
angle, that projections thereof, toward each free end of the
straight legs of the impulse-wave conductor, correspond in size to
perpendicular cross-sectional cuts of the straight legs; or the
first and second impulse-wave conductor portions are separated
parts and arranged at an angle to one another, with an angled
rebound body being positioned between the first and second
impulse-wave conductor parts to pivot about a pivot point lying
between the impulse-wave conductor parts, with a first leg end of
the rebound body lying against an impulse-input-side of the first
impulse-wave conductor part under a spring bias and with a second
other leg end of the rebound body being spaced from the second
impulse-wave conductor part which has the stamp coupled
thereto.
[0007] By redirecting impulse waves, it is possible to arrange a
striking tool to the side of, and substantially spaced from, a
stamp, thereby resulting in a significantly narrower structure of
the joining tool. Such a joining apparatus has fewer impractical
"disturbing contours" and is comparable with a resistance spot
welder tong in its operational possibilities, relative to its
access to joining locations.
[0008] When structuring the impulse-wave conductor, one should
strive that compression waves created by the striking tool in the
impulse-wave conductor also arrive as such, as much as possible, in
the stamp, and not become expansion, or pulling, waves on the way
due to reflection. This is achieved by any of the three structures
described above.
[0009] The first structural version employs the bent, or angled,
impulse-wave conductor, with at least the first and second legs
thereof being as straight as possible and the intermediate portion
extending in a largest possible bow or arc. With this structure,
most of the compression waves are reflected in large obtuse angles
when transitioning from one leg to the other so that the
compression waves arrive at the stamp.
[0010] In the second version, the reflection surface is arranged to
be targeted in the transition area from one leg to the other leg of
the impulse-wave conductor. In this version the impulse-wave
conductor is angled, with an outer angle edge being diagonally
flattened, the flattened area being of such a size and extending at
such an angle that a projection thereof toward each leg
approximately corresponds in size and shape to cross-sectional cuts
of the attached legs. This reflection surface reflects the
compression waves hitting it at only a small angle to a central
axis of the second leg, so that most of the waves also reach the
stamp as compression waves.
[0011] To increase the effectiveness of this version of the
apparatus, it has proven to be beneficial to press a body mass on
the reflection surface with a spring system, with a surface of the
body mass lying on the reflection surface being larger than the
reflection surface and extending beyond it in all directions and
with a natural frequency of the spring-mass-system being half as
great as the impulse wave frequency. This additional mass serves to
ensure that a compression wave hitting the redirecting surface is
mainly reflected as a compression wave and not as an expansion
wave. In this regard, it is beneficial for the additional mass to
be of a material that has a greater wave, or sound, resistance than
does the impulse-wave conductor.
[0012] In the third version of the apparatus, the impulse-wave
redirection is caused by inter-disposition of a force redirection
part. In such an apparatus the impulse-wave conductor is of two
separate parts, with the two impulse-wave conductor parts arranged
at an angle to one another, there being the bent, or angled,
rebound body arranged between the two impulse-wave conductor parts
to be pivotal about an interior pivot point positioned between legs
thereof, a leg end of a first leg of the rebound body lying on the,
input-side, first impulse-wave conductor part under spring force,
and a leg end of a second leg of the rebound body being spaced from
the second impulse-wave conductor part. In this regard, it is
important that the force of the spring is chosen such that the
rebound body is once again made to lie against the first
impulse-wave conductor part for receiving the next wave after it
swings out.
[0013] An air pressure driven plunger can be used as a striker of
the striking tool. It is, however, particularly for reducing
striking noise, beneficial for the impulses to be created by one or
more lined-up piezoelectric actuators. This series arrangement of
the actuators has the advantage of amplifying the magnitude of the
striking, or impulse, amplitude so that a greater stamp path can be
used. The piezoelectric actuators are particularly well suited for
producing a pulsating striking force.
[0014] In a further beneficial embodiment of the apparatus, impulse
waves fed into a die plate, or female mold, are conducted via an
impulse-wave conductor, which is formed in the same manner as is
the impulse-wave conductor feeding impulse waves to the stamp.
Thus, a lower part of the joining apparatus has a lower profile
than for known apparatus.
[0015] In a beneficial further embodiment of the apparatus of this
invention, the impulse-wave conductors coupled to the stamp and die
plate are structured as upper and lower tong arms of a
shearing-principle support device of the joining apparatus. This
embodiment makes possible a quite uncomplicated and low profile
construction of the entire apparatus.
[0016] Further, it is beneficial for a rebound mass to lie against
the impulse-wave conductor at the end of the lower tong arm under
pressure of a spring system to eliminate, or absorb, the impulse
waves. This rebound mass can be replaced by piezoelectric actuators
30, if piezoelectric-actuator-joining force is used, acting on the
die plate at the same time as, or synchronized with, the actuators
acting on the stamp.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Further benefits, characteristics and details of the
invention are explained in more detail below using embodiments
shown in the drawings. The described and drawn features can be used
individually or in preferred combinations in other embodiments of
the invention. The foregoing and other objects, features and
advantages of the invention will be apparent from the following
more particular description of the preferred embodiment of the
invention, as illustrated in the accompanying drawings in which
reference characters refer to the same parts throughout the
different views. The drawings are not necessarily to scale,
emphasis instead being placed upon illustrating principles of the
invention in a clear manner.
[0018] FIG. 1 is a side view of a joining apparatus of this
invention;
[0019] FIG. 2 is an enlarged view of a detail A in FIG. 1;
[0020] FIG. 3 is an enlarged view of a detail corresponding to
detail A in FIG. 1, but for a second embodiment;
[0021] FIG. 4 is an enlarged view of a detail corresponding to
detail A in FIG. 2, but with an embellishment of the second
embodiment;
[0022] FIG. 5 is an enlarged view of a detail corresponding to
detail A in FIG. 1 but for a third embodiment involving a rebound
body between two impulse-wave conductors;
[0023] FIG. 6 is another embodiment of a rebound body, relative to
FIG. 5;
[0024] FIG. 7 is a side view of a further embodiment of a joining
apparatus of this invention; and
[0025] FIG. 8 is a side view of yet another embodiment of a joining
apparatus of this invention, different from that of FIG. 7;
DETAIL DESCRIPTION OF THE INVENTION
[0026] Each embodiment of a joining apparatus shown in FIGS. 1, 7
and 8 is structured in the manner of shears, with an upper tong arm
1 and a lower tong arm 2 being pivotally coupled to one another at
a rotation point 3. End portions 4 and 5 of the upper as well as
the lower tong arms 1 and 2 extend beyond the rotation point 3. A
motivating unit 6 is arranged between these two end portions 4 and
5 for opening forward tong ends and moving them back together. Such
a shearing-tong, with the above described arrangement of the
motivating unit, with the motivating unit being arrange behind a
center of gravity of the shearing tongs, makes possible a narrow
structure for the joining apparatus and improves its
maneuverability by having a favorable distribution of its
masses.
[0027] In the embodiment of FIG. 1, each of the upper tong arm 1
and the lower tong arm 2 forms a ram, or impulse, wave conductor 9,
10. These impulse-wave conductors 9 and 10 pass rearward through
holders 11, 12 that support them. A striking, or pulsating, tool 14
operates on the end 13 of the impulse-wave conductor 9 that extends
through the holder. Impulses created by the striking tool 14 are
transmitted by the impulse-wave conductor as compression waves into
an angled arm 20 of the impulse-wave conductor 9 and from there to
a stamp 7. The striking tool 14 is pressed against an end 13 of the
impulse-wave conductor 9 by a spring 15.
[0028] The lower tong arm 2, which has a female mold, or die plate
8, is also formed as an impulse-wave conductor 10. A rear end 16 of
this impulse-wave conductor 10 extends through the holder 12. A
rebound mass 17 is pressed against this rear end 16 of the
impulse-wave conductor 10 by a spring 18. This spring/impact-mass
system dampens impact waves that are further transmitted by the
stamp 7 to the impulse-wave conductor 10.
[0029] In order to achieve an optimal redirection of the impact
waves from the horizontal leg 19 of the impulse-wave conductor 9 to
the vertical leg 20, an intermediate portion 21 of the impulse-wave
conductor 9 is structured such that the compression waves guided
into this intermediate portion 21 arrive at the end of the vertical
leg 20, and thereby at the stamp 7, as compression waves and not as
expansion waves. In order to best achieve this prerequisite, the
intermediate portion 21, as can be seen in FIG. 2, is in the form
of a bow, or arc, and an arc having the greatest possible radius
should be chosen. Another possible structure is represented in FIG.
3 in which an impact wave traveling along the horizontal leg 19 is
reflected from a flat surface 22 into the vertical leg 20.
[0030] In order that the compression waves from the horizontal leg
19 hitting the surface 22 are also reflected therefrom
predominantly as compression waves and not as expansion waves, an
additional mass body 23 lies against the surface 22 and is pressed
thereagainst by a spring system 40. A surface 24 of the mass body
23, which lies against the surface 22 of the impulse-wave conductor
9, extends on all sides beyond the surface 22 of the impulse-wave
conductor 9, and a natural frequency of the spring-mass-system of
the additional mass body 23 is half as great and the impulse wave
frequency. An effectiveness of the additional mass body 23 is high,
if it is of a material that has a greater wave resistance than does
that of the impulse-wave conductor 9.
[0031] In the embodiment of FIG. 7, impulse-wave conductors 25, 26
are not formed of upper and lower tong arms as in the embodiment of
FIG. 2, rather, here two tong arms 1, 2 are hollow, and the two
impulse-wave conductors 25 and 26 as well as the striking tool 14
and the rebound mass 17 are positioned in the hollow tong arms 1
and 2. This is also true for two spring pressing apparatus 27 and
28 of the striking tool 14 and the rebound mass 17. In this regard,
it is beneficial for the pressing apparatus 27 of the striking tool
14 to be adjustable.
[0032] In the joining apparatus of FIG. 8, piezoelectric actuators
29 are used as a striking tool instead of a pneumatic striking
tool. A plurality of piezoelectric actuators arranged in series
increases impact amplitude to such an extent that the elastic limit
of a material to be joined is exceeded by each impulse. In this
apparatus, instead of using the rebound mass 17 of the embodiment
of FIG. 7, piezoelectric actuators are place in the lower tong arm
which operate on the female mold 8 in time with the actuators 29 on
the stamp 7, and thereby increase a joining strength.
[0033] In the embodiment of FIG. 5, impact waves created by the
striking tool 14 are redirected by a pivotally-mounted rebound body
31. Compression waves created by the striking tool 14 in the
impulse-wave conductor 32 are transmitted into a leg 35 of the
rebound body 31. When this is done, the rebound body pivots about
its pivot point 34 in a direction of an arrow B and a free end of
its leg 36 strikes against a impulse-wave conductor 33 and creates
therein a compression wave which is transmitted further to the
stamp 7. After it has swung out, the rebound body 31 is pivoted
back to its original position opposite the direction of the arrow B
by a return spring 37. So that the rebound body 31 does not apply a
significant impact on the impulse-wave conductor 32 upon its return
pivot, it strikes against an elastic impact damper 38 upon its
return pivot. A force of the return spring 37 is chosen such that
the rebound body 31, after its outward pivot, once again lies
against the first impulse-wave conductor 32 for receiving the
following impulse wave.
[0034] In an embellishment of the rebound body 31, it has, as shown
in FIG. 6, a body sound-stopping, or damping, intermediate layer
39. This intermediate layer 39 eliminates or reduces bending
oscillations, or vibrations, in the rebound body 31.
[0035] The impulse-wave conductor 9, 10, 25, 26, 32, 33 tong shaped
joining tool is of a material (solid, liquid or gas) which provides
very little damping, particularly of a metal having very little of
its own damping.
* * * * *