Note: Descriptions are shown in the official language in which they were submitted.
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Processing Clamp
The invention relates to a processing clamp.
Processing clamps and processing stations for incorporating functional
elements such as
nuts, bolts and similar connecting elements into workpieces made of sheet
metal or sheet
steel, in particular by joining followed by crimping, are known both in terms
of their setup
and their mode of operation.
In particular, DE 103 59 879 B4 discloses a hydraulic processing clamp for
incorporating
functional elements such as nuts, bolts, etc. into workpieces made of sheet
metal or sheet
steel, that comprises a clamp body with a first and second clamp arm, each of
which holds
one part, for example, of a two-piece tool. The two tool parts, mounted on the
clamp arms
which are facing each other, define a working region, in particular a working
gap, in which
the workpiece to be machined or processed and a functional element are
accommodated. To
enable joining and crimping of the function element with the workpiece, at
least one of the
two parts of the tool is designed to be axially movable, namely in the
direction of the other
opposite facing tool part. Specifically for crimping, the tool part designed
to be axially
movable comprises a tool pushrod, also known as a plunger. The tool pushrod is
axially
movable from a starting position into an operating position to close the
processing clamp,
wherein the working gap can be reduced in such a way that the tool pushrod is
supported on
the functional element to be incorporated into the workpiece, and this is
supported on the
workpiece. The pressure generated by a hydraulic pressure cylinder of the
hydraulic actuator
device is transferred directly to the tool pushrod and the functional element
is thereby fixed
in the workpiece by a crimping action, and preferably by permanent material
deformation,
for example of the functional element and/or the workpiece. In the known
processing clamp
or setting clamp, the adjustment motion of the tool pushrod or plunger onto
the workpiece is
executed with a large stroke length but with reduced power, and specifically
with an
adjustment device provided for this purpose, while in the case of an already
closed
processing clamp, i.e. in the operating position, the actual processing or
crimping is effected
by the hydraulic actuator device with an extremely short stroke, but with
large force. In
order to achieve this the processing clamp is designed such that the pressure
piston of the
pressure cylinder of the hydraulic actuating device is arranged coaxially with
the tool plunger,
however, in such a way that the adjusted tool pushrod is axially spaced apart
from the
pressure piston of the pressure cylinder. Via a coupling means which is
radially displaceable
relative to the axis of the tool plunger, in particular a pressure piece, the
gap that is present
between the pressure piston of the pressure cylinder and the adjusted tool
pushrod in the
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working position is bypassed, so that during the crimping operation the
pressure piston acts
on the tool pushrod via this pressure piece and transfers the high processing
force generated
directly to the tool pushrod. When the tool pushrod has been moved back into
the starting
position, or with the processing clamp open, the pressure piece is located at
the side of the
tool pushrod and thereby releases the space required for the tool pushrod to
move back into
its starting position again.
Disadvantageously, due to the hydraulic pressure cylinder, the known hydraulic
processing
clamps have high maintenance requirements and the actuation force and/or
actuation
movement thus generated is difficult to precisely control and regulate. Also,
due to the
hydraulic pressure cylinder that is connected to the tool pushrod along the
axis of motion,
such hydraulic processing clamps have a high configuration, which in some
applications
involving confined spaces can lead to collisions with other components.
Starting from this, an object of the invention is to specify an improved
processing clamp
which, while maintaining the advantage of a low overall height, also allows an
individually
adjustable processing force.
In the context of the invention the term "processing clamp" is understood in
particular to
mean a device by means of which workpieces can be machined or processed under
the
application of large forces, and which for this purpose comprises at least two
tool parts that
are moveable relative to each other forming a working gap, of which at least
one tool part
can be mechanically actuated and of which a further tool part forms a
workpiece abutment or
another workpiece element. The processing clamp can also be part of a
processing station or
processing device.
The actuator device comprises a pneumatic or electric drive unit for
generating the
processing force and for directly transmitting the generated processing force
onto the first
tool part, or that the actuator device comprises a pneumatic, hydraulic or
electric drive unit
for generating an auxiliary processing force and a force translation mechanism
that can be
connected to the first tool part in a driving manner and is designed to
translate the auxiliary
processing force into the processing force and directly transmit this to the
first tool part. In
particular advantageously by using an electric drive unit, in particular of a
servo motor unit,
a much more precise control of the processing motion, in particular the
working stroke and
the processing force, is possible. As a further advantage, by arranging the
servo motor unit
on the front face, a low overall height of the processing clamp is obtained.
Alternatively, the
actuating device can be arranged on the side of the processing clamp, in
particular in the
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area of the yoke section of the clamp body, and be connected to the first tool
part in a
driving manner via a force translation mechanism. This enables an auxiliary
processing force
reduced by up to 50% to be generated while maintaining a low overall height,
in order to
generate, due to the deflection and the magnification of this force by means
of the force
translation mechanism, a processing force comparable to that of a known
actuating device.
This allows drive units with a lower performance to be used, which are less
expensive and
have a lower energy consumption.
As a further advantage, in the working position the actuating device
comprising a pneumatic
or electric drive unit can be connected to the first tool part via a force
transmission element
which is radially displaceable relative to the tool axis, namely by
incorporating the force
transmission element into a free space extending along the tool axis between
the actuating
device and the first tool part.
In an alternative embodiment the actuating device can move along the tool axis
jointly with
the first tool part and be designed such that it can be fixed on the first
clamp arm in the
working position. This eliminates the need to provide a force transmission
element.
In an advantageous embodiment the auxiliary processing force generated by the
actuating
device is oriented radially to the tool axis or in the opposite direction to
the processing force,
wherein the force translation mechanism is designed for translating the
auxiliary processing
force provided by the actuating device into a processing force oriented along
the tool axis
and acting in the direction of the first tool part. In a preferred embodiment
the force
translation mechanism is also designed to magnify the auxiliary processing
force provided by
the actuating device.
The force transmission mechanism can have different designs, in particular
this can be a
lever mechanism, a toggle lever mechanism or a wedge mechanism.
Advantageously, the first and second clamp arm are connected together via a
clamp yoke
section, wherein the actuating device comprising a pneumatic, hydraulic or
electric drive unit
is arranged in the area of the clamp yoke section on the side of the clamp
body and the
associated force transmission mechanism is arranged in the area of the first
clamp arm.
The first tool part is preferably designed as a tool pushrod or plunger.
As a further advantage, the adjustment device comprises a pneumatic, hydraulic
or electric
4
drive unit by means of which an adjustment motion of the first tool part is
generated. This
ensures that the adjustment device is configured to generate an adjustment
motion of the
first tool part with high stroke length, but only low adjustment force.
The terms "approximate", "substantially" or "approximately" in the context of
the invention
mean deviations from each exact value by +/-10%, preferably by +/-5% and/or
deviations
in the form of variations which are insignificant to the functionality.
Further developments, advantages and application possibilities of the
invention also arise
from the following description of exemplary embodiments and from the drawings.
All features
described and/or depicted in principle form the subject matter of the
invention either alone
or in any combination, regardless of how they are drawn up by reference
thereto. The
content of the claims is also considered part of the description. The scope of
the claims
should be given the broadest interpretation consistent with the specification
as a whole.
Hereafter the invention is explained in more detail by means of exemplary
embodiments
illustrated in the figures. These show:
Fig. 1 a schematic side view of a processing clamp with a first embodiment
of an
actuating device according to the invention,
Fig. 2 a schematic side view of a processing clamp with a second
embodiment of
an actuating device according to the invention,
Fig. 3a-c schematic functional diagrams relating to different
embodiments of a force
translation mechanism.
The general design and mode of function of a processing clamp i are known for
example from
documents DE 103 59 879 B4 or EP 1 984 132 Bl.
Such a processing or placement clamp is hereafter referred to by reference
numeral 1. In
contrast to the prior art however, the processing clamp 1 according to the
invention does not
have a direct hydraulic actuating device.
The processing or placement clamp 1, shown only schematically by way of
example in Figure
1 and 2, is used for incorporating functional or connection elements, for
example nuts, bolts
or the like, by joining and/or crimping them into workpieces made of sheet
metal, and/or for
connecting workpieces manufactured from sheet metal by means of clinching.
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To this end the processing clamp 1 comprises at least one preferably C-shaped
or U-shaped
clamp body 2 with a first and second clamp arm 2.1, 2.2, that are connected to
each other
via a clamp yoke section 2.3. The clamp body 2 is preferably configured as a
single piece or
5 a single part.
The processing clamp 1 can also be part of a workstation not shown in the
drawings, wherein
the processing clamp 1 forms for example the manual workstation therein. For
this purpose,
the clamp body 2 with its clamp yoke section 2.3 can be fixed, for example, on
a machine
frame not shown in the drawings or a holder, also not shown. Appropriate
holding and
connection means are indicated in Figures 1 and 2 on the clamp yoke section
2.3 by way of
example.
In addition, the processing clamp 1 has a multi-part tool 3 that comprises at
least a first tool
part 3.1 and a second tool part 3.2, wherein the at least two tool parts 3.1,
3.2 are designed
to be moveable relative to each other and define a working region, preferably
a working gap
AB.
The first tool part 3.1 is arranged such that it can be traversed along a
vertical tool axis WA
on the first clamp arm 2.1 to close the working region AB and the second tool
part 3.2 is
arranged on the second clamp arm 2.2 to form a workpiece abutment for at least
one
workpiece, wherein the first tool part 3.1 is adjustable by means of an
adjustment device 4
and an adjustment motion generated thereby from a starting position AU into a
working
position AR and vice versa. The adjustment device 4 can be designed as an
electrical,
pneumatic or hydraulic adjustment device which produces an adjustable stroke
length that
substantially corresponds to the path from the starting position AU to the
working position
AP along the tool axis WA.
In the working position AR the first tool part 3.1 or a functional element
held on the first tool
part 3.1 either rests against a workpiece supported on the workpiece abutment
or on the
second tool part 3.2, or is spaced only a small distance apart therefrom. The
first tool part
3.1 is designed for example as a punching-head style crimping tool, which is
only shown
schematically in Figures 1 and 2. Such a punching-head style crimping tool can
be designed,
for example, in the form of a tool pushrod or a so-called plunger, which can
be guided
displaceably along the tool axis WA in a housing mounted on the first clamp
arm 2.1 for an
axial adjustment stroke. As the second tool part 3.2, a matrix-like tool part
is provided, for
example. It is the interaction of the two tool parts 3.1, 3.2 that effects the
joining and
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crimping of the respective component(s) in the workpiece.
The adjustment device 4 causes an adjustment motion of the first tool part 3.1
with a large
adjustment stroke, but with only low adjustment force. The size of the
adjustment force is
dimensioned in this case in such a way that it ensures the execution of an
adjustment
movement with corresponding adjustment stroke of the first tool part 3.1 with
the functional
element accommodated thereon, which means that this is at least equal to the
weight of the
first tool part 3.1 and of the functional element. In order to transmit the
adjustment motion
generated by the adjustment device 4, the first tool part 3.1 can have a
gearing system, in
which a pinion of the adjustment device 4 engages. For this purpose the
adjustment device 4
is mounted on the first clamp arm 2.1.
To crimp the functional element however, a processing movement of the first
tool part 3.1
with a small working stroke but with high processing force is required,
following the
adjustment motion with large adjustment stroke, which movement is generated by
an
actuating device 5, 7 for applying a high processing force F acting along the
tool axis WA to
the first tool part 3.1 after the adjustment into the working position AR by
means of the
adjustment device 4. The adjustment stroke therefore exceeds the working
stroke by several
times.
The actuating device 5 is formed by a pneumatic or electric drive unit for
generating the
processing force F and for directly transmitting the processing force F
generated onto the
first tool part 3.1. The actuating device 5, 6 is directly connected in a
driving manner to the
first tool part 3.1, where appropriate also by means of an additional force
transmission
element 6. The actuation device 5 is joined to the first tool part 3.1 along
the tool axis WA
and is fixed to the first clamp arm 2.1. The actuating device 5 generates a
processing motion
oriented along the tool axis WA, with a low working stroke length but with a
high processing
force F.
For example, the actuating device 5 can be moved jointly with the first tool
part 3.1 and
locked to the first clamp arm 2.1 on completion of the adjustment motion, in
order then to
interact with the first tool part 3.1 without a force transmission element 6,
Also, the actuating unit 5 can be rigidly mounted on the clamp arm 2.1 and the
distance
produced by the adjustment movement or the adjustment stroke between the
actuating
device 5 and the first tool part 3.1 can be bridged by means of a preferably
passive force
transmission element 6, which element comes to rest directly on the
aforementioned
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elements. For this purpose the force transmission element 6 is designed to be
radially
displaceable with respect to the tool axis WA, which is introduced between the
first tool part
3.1 located in the working position AR and the actuating device 5, in order to
ensure a direct
transmission of the processing stroke with the associated processing force
onto the first tool
part 3.1.
Alternatively, the actuating device 7 is designed as a pneumatic, hydraulic or
electric drive
unit for generating an auxiliary processing force HF and a force transmission
mechanism 8
that can be connected to the first tool part 3.1 in a driving manner, which is
configured to
translate the auxiliary processing force HF into the processing force F and
transmit this onto
the first tool part 3.1. The auxiliary processing force HF generated by the
actuating device 7
is oriented either parallel to the tool axis WA or perpendicular to,
preferably radially to the
tool axis WA, and by means of the force translation mechanism 8 is converted
into the
required processing movement which acts along the tool axis WA in the
direction of the first
tool part 3.1, and, if necessary, amplified.
For this purpose the force translation mechanism 8 can have different modes of
operation,
examples of which are shown in Figures 3a to 3c.
In the embodiment according to Figure 3a the force translation mechanism 8
comprises a
lever mechanism which is designed to amplify the auxiliary processing force HF
generated by
the actuating device 7, wherein the processing force F generated by the force
translation
mechanism 8 from the auxiliary processing force HF is oriented opposite to
said processing
force F.
In a further embodiment in accordance with Figure 3b, the force translation
mechanism 8 is
implemented as a wedge mechanism, which is designed for generating a force
transmission
by means of a wedge effect. For this purpose the wedge mechanism comprises at
least two
mechanism parts which abut each other over a contact surface extending in an
inclined
plane, wherein the inclined plane extends slopingly to the tool axis WA. This
causes the
auxiliary processing force HF acting radially to the tool axis WA to be
converted into the
processing force F acting along the tool axis WA in the direction of the first
tool part 3.1, or
processing direction. Also, with an appropriate design of the wedge mechanism
an
amplification of the auxiliary processing force HF can be effected.
Finally, in the embodiment according to Figure 3c the force translation
mechanism 8
comprises a toggle lever mechanism, by means of which the auxiliary processing
force HF
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acting radially to the tool axis WA is also converted into the processing
force F acting along
the tool axis WA in the direction of the first tool part 3.1, or processing
direction.
Alternatively, an alternative suitable force translation mechanism 8 can also
be provided,
S which is configured to perform a corresponding translation of the
auxiliary processing force
HF into the processing force F and transmitting this onto the first tool part
3.1 and if
appropriate, generates an additional force amplification effect.
The invention has been described above based on exemplary embodiments. It is
understood
that numerous changes and modifications are possible without departing from
the scope of
the appended claims.
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List of reference numerals
1 processing clamp
2 clamp body
2.1 first clamp arm
2.2 second clamp arm
2.3 clamp yoke section
3 tool
3.1 first tool part
3.2 second tool part
4 adjustment device
5 actuating device
6 force transmission element
7 actuating device
8 force translation mechanism
AB working region
AR working position
AU starting position
F processing force
HF auxiliary processing force
WA tool axis
