Note: Descriptions are shown in the official language in which they were submitted.
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HOSE BUNDLE FOR A WELDING DEVICE
The present invention relates to a hose bundle arrangement
with a hose bundle for a welding device.
Hose bundles of the type mentioned at the beginning are
used as transfer device between the handling part of a
welding device, that is to say the so-called welding torch,
and the actual welding unit which is essentially used for
welding current generation and for the supply or for the
connection of the welding media, such as the welding wire
and the shielding gas. As transfer device, the hose bundle
in this case is primarily assigned the task of ensuring the
current and media supply over the distance to the welding
unit, without impairing the handling of the welding torch.
This applies to a particular degree if one is concerned
with hose bundles which are used for installation on a
welding robot, in the case of which hose bundles, the hose
bundle is arranged between a welding torch installed on a
robot wrist and a wire feed device installed in the region
of a fixed robot base, and the hose bundle on the one hand
may not hinder the complex kinetics of the overlaid
movements of the robot arm members and on the other hand
the mechanical loadings of the hose bundle arising in
connection with the movement of the robot arm should be as
low as possible in order to keep wearing as low as
possible.
The torsional loadings arising in operation, which can
admittedly be avoided in that a rotary coupling is arranged
in the region of the robot wrist in order to keep the hose
bundle torsion-free to the greatest extent possible, prove
particularly damaging for the service life of a hose
bundle. However, from this results the disadvantage that
the mass in the region of the robot wrist is increased and
that the heat transmission from the welding torch onto the
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hose bundle and thus the dissipation of the welding heat
from the welding torch is impaired by means of the
intermediate arrangement of a coupling element.
The present invention is therefore based on the object of
suggesting a hose bundle for welding devices which can be
loaded with torsion to a particular degree, in order to
enable a long service life even without an intermediate
arrangement of a rotary coupling in the region of the robot
wrist.
In the case of the hose bundle according to the invention,
the channel wall of the guide channel has a coil spring
arrangement with at least one coil spring winding.
In the case of the hose bundle according to the invention,
the guide channel is therefore constructed in a
sufficiently torsionally rigid manner in order to prevent a
damaging loading of the outer insulation or the conductor
arrangement by means of torsional stresses to the greatest
possible extent.
According to an advantageous embodiment, the supporting
structure has a tubular carrier which is provided with a
torsionally rigid reinforcement. In this case, the carrier
is essentially assigned the task of forming the
reinforcement to a tubular wall. For example, the carrier
can be formed from a plastic hose which has a torsionally
rigid jacket in the form of a braid or network, for example
made from a metal or a sufficiently rigid, particularly
pressure-resistant, non-metal material.
In a particularly preferred embodiment, the supporting
structure has a coil spring arrangement with at least one
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coil spring winding which enables a bending of the hose
bundle in operation of a robot and has sufficient torsional
rigidity for transmitting an angle of rotation without a
torsional stress acting to a damaging degree on the outer
insulation of the conductor arrangement.
Depending on the length of the hose bundle and the size of
the angle of rotation of a welding torch, it can also prove
advantageous for constructing the coil spring arrangement
to arrange a plurality of coil spring windings
concentrically. In this case, it can in particular be
advantageous, in the case of a large rotational angle range
in both directions of rotation, for constructing the coil
spring arrangement to provide two coil spring windings
which have an opposed winding direction.
Independently of the number and layout of the coil spring
windings used for constructing the coil spring arrangement,
it is advantageous to use the coil spring arrangement
itself as electrical conductor arrangement, in order to
enable a realisation of the hose bundle which is minimised
in terms of diameter with a minimal configuration of the
hose bundle.
If, in a particularly preferred exemplary embodiment of the
hose bundle, an annular gap between the coil spring
arrangement and a channel wall of an accommodation channel
is formed in a transfer section, which is axially delimited
by force introduction devices, of the coil spring
arrangement in the relaxed state, not only can a relieving
of the insulation hose of a torsional loading, that is to
say a reduction from the torsional loading, be achieved,
but also, depending on the dimensioning of the annular gap,
a complete decoupling of the insulation hose from the
torsional loading accommodated by means of the coil spring
arrangement can be achieved in the maximum case.
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Preferably, the channel wall is formed by the conductor
arrangement.
In order to enable an electrical decoupling between the
coil spring arrangement and the conductor arrangement in
the transfer section of the coil spring arrangement, an
insulating covering of the coil spring arrangement or an
insulating lining of the conductor arrangement is provided
in the annular gap.
In order to be able to connect the hose bundle to a welding
unit or a wire feed device, the hose bundle is provided
with a connection piece on its wire feed end, which is used
both for current transfer and for force introduction
between the welding unit or the wire feed device and the
hose bundle. As a result of this, the direct connection of
the wire feed end of the hose bundle to a rotary coupling
is possible, which rotary coupling makes it possible to
limit the torsional forces, which act on the hose bundle or
the coil spring arrangement during operation due to torsion
of the robot wrist, to a maximum value.
The hose bundle arrangement according to the invention is
provided with a coupling device at its wire feed end, which
has a plug part formed by means of the connection piece,
which plug part is rotatably accommodated in a fixed socket
part for connection to a wire feed device. Due to the
coupling device, which is arranged at the wire feed end,
that is to say the end of the hose bundle, which is remote
from the robot wrist, a heat transmission resistance
defined by the coupling device, which hinders the heat
dissipation from the robot wrist, only results at the end
of a heat transmission path defined by means of the hose
bundle, so that a substantially improved heat dissipation
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of the heat arising at the welding torch is possible compared
to the case of installation of a rotary coupling in the region
of the robot wrist.
If, furthermore, the socket part has a housing part constructed
as an electrical conductor arrangement, which housing part has
a coupling element in an annular gap formed between the plug
part and a sleeve receptacle, which coupling element is used
both as a radial bearing and for current transfer, a
particularly good heat transmission is realised in co-operation
with the plug part in the region of the rotary coupling.
In some embodiments of the invention, there is provided a hose
bundle arrangement with a hose bundle for a welding device and
for connection to a robot wrist, wherein the hose bundle has a
guide channel for accommodating and guiding a welding wire and
an electrical conductor arrangement covered by means of
insulation, wherein the hose bundle arrangement has a coupling
device for the rotatable connection of the hose bundle to a
wire feed device, wherein the coupling device has a plug part
formed by means of a connection piece, which is accommodated
rotatably in a fixed socket part for connection to the wire
feed device, wherein a channel wall of the guide channel has a
torsionally rigid supporting structure, and wherein the
torsionally rigid supporting structure is on a side of the
robot wrist connected to a connection element for providing a
force transmission between the torsionally rigid supporting
structure and the robot wrist.
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An embodiment of the invention is described in more detail
below on the basis of the drawing. In the figures:
Fig. 1: shows a welding robot with a hose bundle
arrangement arranged on the robot arm;
Fig. 2: shows the hose bundle arrangement used on the
welding robot shown in Fig. 1 in a detail view;
Fig. 3: shows the hose bundle arrangement shown in Fig. 2
in a partial sectional illustration according to
the section line course III - III;
Fig. 4: shows an enlarged illustration of a distal
connection end according to cutaway IV of the
hose bundle arrangement shown in Fig. 3;
Fig. 5: shows an enlarged illustration of a proximal
connection end according to cutaway V of the hose
bundle arrangement shown in Fig. 3.
Fig. 1 shows a welding robot 10 with a body part 12
pivotable about a vertical axis 11, on which an articulated
arm 13 is arranged. On a distal end 14 of a lower arm
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element 15, a robot wrist 17 pivotable about a wrist axis
16 is constructed, which robot wrist connects a torch base
18 of a welding torch 19 to the lower arm element 15 in an
articulated manner.
A hose bundle 21 is connected directly or, in the present
case indirectly via a connection element 20, to the torch
base 18, which hose bundle extends from the connection
element 20 or the torch base 18 as far as to a coupling
device 22 constructed at a proximal end 31 of the hose
bundle 21, which coupling device is used for connecting the
hose bundle to a wire feed device 23 constructed as a wire
feed case here.
In the exemplary embodiment shown in Fig. 1, a hose bundle
arrangement 24 formed from the hose bundle 21 and the
coupling device 22 is connected Indirectly via a connection
element 25 to the wire feed device 23.
Fig. 2 shows the hose bundle arrangement 24 with the
connection element 20 arranged at the distal end 14, which
is constructed as a sensor device in the present case,
which sensor device has a force sensor which is not shown
in any more detail here, in order to introduce a suitable
evasive movement of the welding robot 10 in the event of a
collision of the welding torch 19 with a workpiece. In
contrast with the illustration of the hose bundle
arrangement 24 in Fig. 2, it is also possible however to
connect the distal end 14 of the hose bundle 21 to the
torch base 18 directly.
The hose bundle arrangement 24 shown in Fig. 2 is used for
current and media supply of the welding torch 19 and to
this end has a guide channel 26 in the hose bundle 21, as
shown in Fig. 3, which is primarily used for guiding
through a welding wire, which is not shown here in any more
detail and is conveyed from the wire feed device 23 into a
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torch head 27 (Fig. 1) of the welding torch 19, and also
for conveying a shielding gas.
Further, the hose bundle arrangement 24 shown in Fig. 2 has
a conductor channel 28, which here encloses the hose bundle
21 and is used for guiding electrical signal lines 29 or
media lines, for example for conveying cooling water, not
shown here in any more detail.
Fig. 3 shows a connection end 30, constructed at the distal
end 14 of the hose bundle 21, and also a connection end 32,
constructed at a proximal end 31 of the hose bundle 21,
which are arranged on both sides of a transfer section 52
of the hose bundle 21, in a sectional illustration.
As can particularly be seen from the enlarged detail views
of the distal connection end 30 and of the proximal
=connection end 32 in the Figs 4 and 5, a channel wall 33 of
the guide channel 26 is defined in the exemplary embodiment
shown here by means of the coaxial arrangement of two coil
spring windings 34, 35 which together form a coil spring
arrangement 36. In the present case, further, with respect
to a guide channel axis 37, the coil spring windings 34, 35
are provided with opposed winding directions, so that a
supporting structure which is sufficiently torsionally
rigid in both rotational angle directions can be realised.
The coil spring arrangement 36 or the outer coil spring
winding 35 is in the present exemplary embodiment provided
with a hose coating 40 made of an insulating material, the
coil spring arrangement 36 being arranged in an
accommodation channel 54, the channel wall 55 of which is
formed by the conductor arrangement 21. The hose coating 40
fills an annular gap 42 constructed between the coil spring
arrangement 36 and an electrical conductor arrangement 41
arranged coaxially to the guide channel axis 37. In a
contact region 43 of the connection end 30, the coil spring
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arrangement 36 or the outer coil spring winding 35 is
released from the hose coating 40 and accommodated in an
end sleeve 44, constructed as a ferrule here, which is
preferably formed from a copper material. The end sleeve 44
is used on the one hand for force transmission between the
coil spring arrangement 36 and the connection element 20
and also on the other hand for current transfer from the
conductor arrangement 41 to the connection element 20.
Accordingly, a connection piece 45 is provided at the
proximal end 31 of the hose bundle 21, which has a
connection region constructed as an end sleeve 46 for
connection to the coil spring arrangement 36. Adjacently to
the end sleeve 46, the connection piece 45 integrally
blends into a coupling end 47, which is used for a
connection to a socket part 48, which connection can be
rotated about the guide channel axis 37, of a coupling
device comprising the coupling end 47 and the socket part
22. For the releasable connection of the coupling end 47 of
the connection piece 45 to the socket part 48, the coupling
device 22 has a locking sleeve 50 which can be displaced on
a latching device 49, which locking sleeve in the case of
the exemplary embodiment shown in Fig. 5 releases the
latching connection between the latching device 49 and the
coupling end 47 of the connection piece 45 in the case of a
displacement to the right and thus enables a removal of the
proximal connection end 32 of the hose bundle 21 from the
coupling engagement.
The connection piece 45 is thus used both for producing a
mechanically locking coupling engagement into the coupling
device 22 or the socket part 48 of the coupling device 22
and for producing an electrically conductive connection
between the conductor arrangement 41 of the hose bundle 21
and the connection element 25 connected to the socket part
48, which connection part is connected to the power supply
of the wire feed device 23. In this case, the current
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transfer takes place in the region of he coupling device 22
essentially from the socket part 48 via a coupling element
51 constructed in the manner of a cylinder sleeve to the
coupling end 47 of the connection piece 45. The coupling
element 51 accommodated in a housing part 56 is furthermore
used as a radial bearing of the coupling end 47 in order to
enable a torsion of the coupling end 47 in the socket part
48 of the coupling device 22 which is as low-friction as
possible.
