Note: Descriptions are shown in the official language in which they were submitted.
Agricultural machine and agricultural machine combination
The invention relates to an agricultural machine and an agricultural machine
combination.
Background
Agricultural machines that are hitched to a tractor are usually configured for
use in fields, on
the one hand, and for transport on roads and tracks, on the other. Such
machines include, for
example, soil cultivating machines and spraying machines, but also seed drills
and mowing
machines. The respective agricultural machine is prepared for its
corresponding purpose with
the aid of work tools.
Work tools that are arranged on a frame of the agricultural machine can
regularly be moved
between a working position and a transport position, whether this is by means
of individually
moving the work tool and/or moving parts of the frame on which the work tools
are arranged.
In the working position, the work tools are positioned so as to carry out work
or cultivation
corresponding to the respective purpose of the agricultural machine. The work
tools are
positioned in the transport position when the agricultural machine is not
moved by means of
the tractor for agricultural work, but for transporting the agricultural
machine, for example on
roads or tracks. In conjunction with soil cultivation tools, this means, for
example, that the soil
cultivation tools are usually raised and thus removed from the ground, whereas
the soil
cultivation tools in the working position come into contact with the ground in
order to carry out
the soil cultivation. The situation is similar, for example, with work tools
of a mowing machine,
which can also be moved into a transport position.
For such agricultural machines, it is known to use a support or transport
wheel device with one
or more support or transport wheels in the transport position, which roll on
the ground during
a transport journey and thus support the frame with the work tools. The frame
with the work
tools of the agricultural machine is then supported by the tractor-side
coupling device, via which
the agricultural machine is coupled to the tractor, on the one hand, and the
support wheel
device, on the other, for the transport journey. It can be provided during
field work with the
agricultural machine, when the work tools are in the working position, to lift
out or fold in one
or more support wheels so that they are not in contact with the ground. In
contrast, the support
wheel is folded out or extended for the transport journey so that it comes
into contact with the
ground.
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The support of the frame with the work tools during the transport journey on
the tractor-side
coupling device, on the one hand, and by means of one or more support or
transport wheels,
on the other hand, leads to different loads on the tractor-side coupling
device by the coupled
agricultural machine during a transport journey over uneven ground. This can
lead to the axle
load distribution for the tractor being impaired, which negatively affects the
driving stability of
the agricultural machine combination with a tractor and agricultural machine
coupled thereto.
Document EP 2 289 295 Al discloses a cultivation assembly consisting of a soil
cultivation
device with linkage points arranged on a support frame for attachment to a
tractor three-point
linkage, wherein side frames, side frames with soil cultivation tools and
associated trailing
rollers are arranged on the support frame. The soil cultivation device
consists of several device
units which, together with the trailing rollers, can be pivoted around
horizontal axes and folded
into the support frame. The device consists of two side frames carrying soil
cultivation tools
arranged directly next to each other, each of which can be pivoted into a
transport position
together with the trailing rollers. It is provided that a narrow central
roller element is arranged
on the support frame in the centre of the cultivation assembly between the
trailing rollers
associated with the respective side frames.
Document FR 2 886 511 Al discloses a soil cultivating machine with at least
one trailed lifting
frame, which operates at an adjustable depth in the ground, at least on the
ground, by means
of a reference member coupled thereto. The chassis of this reference member
with a roller is
a series of wheels with tyres made of a flexible material in the transport and
working position
of the frame. The transport and feeler wheels of the reference element are
mounted
independently, either individually or in groups.
Document EP 2 232 974 Al discloses an agricultural device that can be coupled
to the coupling
element of a tractor and that has at least one support device arranged on the
side of the device
facing away from the coupling element and having at least one running wheel,
which support
device is arranged so as to be movable relative to the device via a linkage
with the frame of
the device. The linkage is associated with a lifting element that is effective
in two directions,
with which the support device can be optionally lifted off the ground and
pressed against the
ground for at least partial lifting of the device or parts of the device
during transport. The linkage
is designed as the support device which, when raised, can be moved in the
direction of the
coupling element and/or the tractor and above the frame of the device.
Document EP 3 242 543 discloses an agricultural implement with additional
running gear,
which is carried in the three-point hydraulic system of a towing vehicle and
improves the
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steering ability of the vehicle with an additional spring-loaded support
wheel. A dead centre
mechanism lifts the support wheel with spring force when the implement is in
the working
position.
Document DE 10 224 861 Al describes an agricultural device that can be coupled
to the three-
point linkage of a tractor and having at least one support wheel arranged on
the rear of the
device, which support wheel is arranged so as to be movable in an upright
direction relative to
the device via a linkage with the frame of the device. The linkage is
associated with a double-
acting hydraulic cylinder, with which the support wheel can be optionally
lifted off the ground
and pressed against the ground to relieve the three-point linkage and reduce
the rear wheel
load of the tractor. The two chambers of the hydraulic cylinder are each
connected to a
hydraulic system with a line. An accumulator element and an unlockable shut-
off element are
arranged in the hydraulic line leading to the chamber of the hydraulic
cylinder that presses the
support wheel against the ground.
Document EP 2 988 584 discloses a soil cultivation device, which is provided
with a chassis,
which carries part of the weight of an additional soil cultivation device.
Document EP 1 466 516 Al discloses an agricultural trailer implement, which
has a frame to
be hitched to a tractor using a three-point linkage with two lower hitching
points and one upper
hitching point. The device has two chassis that are connected to the frame to
allow folding
around a joint. An implement is mounted on each chassis. A wheel frame is
connected to the
main frame via a second swivel joint, which is controlled by a hydraulic
actuator.
Document EP 2 422 598 A2 discloses a soil cultivation combination with at
least one towing
vehicle and a towed agricultural soil cultivation device and/or seeder, which
has at least one
transport axle with variable height adjustment and at least two running
wheels, which is
connected to a device frame via at least one joint. A damping device arranged
between the
device frame and the height-adjustable transport axle is provided, wherein the
transport axle
forms a vibration absorber.
Document US 10,638,653 B2 discloses a caster assembly, which has a frame and
is
configured to be pivotally coupled with a tool bar. Furthermore, a sub-frame
rotatably
connected to the frame and a connecting linkage configured to control the
movement of the
frame relative to the tool bar are provided. The caster assembly comprises a
locking assembly,
which has a locking lever moveably coupled to the frame. The locking lever has
a locking
element and a release element. A locking structure fixedly coupled with the
auxiliary frame and
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a drive element fixedly connected to the connecting linkage are provided. The
locking element
is configured to block a rotation of the auxiliary frame relative to the frame
whilst the locking
element engages with the locking structure, and the drive element is
configured to contact the
release element when the connecting linkage moves the frame downwardly
relative to the
frame to drive the locking element and release the locking structure.
Summary
The object of the invention is to provide an agricultural machine and an
agricultural machine
combination with a tractor and agricultural machine, which assist safe driving
during a transport
journey.
This object is achieved by an agricultural machine to be hitched to a tractor
as well as an
agricultural machine combination according to independent Claims 1 and 13.
Embodiments
are the subject of dependent claims.
According to one aspect, an agricultural machine to be hitched to a tractor is
provided, which
has the following: a frame; work tools, which are arranged on the frame and
can be moved
between a working position and a transport position; a coupling device, which,
for hitching to
a tractor, is configured to be coupled to a tractor-side coupling device; and
a support wheel
device, which is configured to support the frame together with the work tools
during a transport
journey, when the work tools are arranged in the transport position. The
support wheel device
comprises the following: a support wheel, which rolls on the ground during the
transport
journey, a carrier means, by means of which the support wheel is arranged on
the frame and
can be moved into various positions with respect to the frame for the
transport journey, and a
hydraulic system, which is connected to the carrier means and is configured to
allow resilient
deflection of the support wheel during the transport journey by moving the
support wheel out
of an extended position into a contrastingly resiliently deflected position of
the various positions
counter to a counterforce provided by the hydraulic system. A supporting force
provided by the
support wheel device during the transport journey is substantially the same in
the extended
and the resiliently deflected position.
According to a further aspect, an agricultural machine combination with a
tractor and an
agricultural machine with the aforementioned design is provided, which is
connected to the
tractor.
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The support or transport wheel device supports with the support or transport
wheel in different
positions of the carrier means, which then correspond to different positions
of the support
wheel in relation to the frame, with constant force. One or more support or
transport wheels
can be provided. If the frame with the work tools, on which other parts or
components of the
agricultural machine can optionally be arranged, is supported solely on the
tractor-side
coupling device, on the one hand, and the one or more support wheels, on the
other hand,
during the transport journey, the substantially same supporting force provided
by means of the
support wheel device in the various positions causes a substantially constant
load on the
tractor-side coupling device due to the support of the agricultural machine
thereon, whereby
the coupled agricultural machine does not impair the axle load distribution
for the tractor during
the transport journey, in particular including not when travelling over uneven
ground when the
support wheel resiliently deflects. It is also ensured that permissible axle
loads on the tractor
are not exceeded. This helps ensure a safe transport journey on roads and
tracks.
Operator comfort is enhanced for the driver of the tractor. It is not
necessary to loosen the top
link of a coupling of the agricultural machine to the tractor in order to
maintain an even axle
load distribution.
The agricultural machine can have work tools of one or more types of work
tools. In one
embodiment, a plurality of rows or arrangements of identical or different
works tools can be
arranged one behind the other in the direction of travel and extending
transversely thereto.
The support wheel device is assigned to the rows or arrangements together.
The support wheel can be moved into at least one further resiliently deflected
position of the
various positions, which is different from the resiliently deflected position,
when it is resiliently
deflected relative to the extended position, wherein the supporting force
provided by the
support wheel device during the transport journey is substantially the same in
the extended
and the further resiliently deflected position. In this way, the support or
transport wheel can
(resiliently) deflect into a plurality of resiliently deflected positions
during the transport journey,
wherein the supporting force provided by the support wheel device for the
frame with the work
tools is substantially the same both in the extended and in the various
(resiliently) deflected
positions.
The extended position can form an end position for moving the support wheel
into the various
positions, in which end position the support wheel is fully extended. In this
embodiment, the
supporting force provided by the support device during the transport journey
is constant,
starting from the fully extended position of the support wheel during
resilient deflection.
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The retracted position and / or the further retracted position can be
different from an end
position opposite the extended position, in which the support wheel is fully
(resiliently)
deflected. Alternatively, the retracted or the further retracted position
corresponds to the
opposite fully deflected end position.
With the agricultural machine, it can be provided that a force provided by the
hydraulic system
is different in the extended position and the resiliently deflected position
and that a degree of
efficiency of a conversion of the force provided by means of the hydraulic
system into the
supporting force is different in the extended and the resiliently deflected
position. In order to
provide substantially the same supporting force of the support wheel device,
during the
transport journey during the transition between the extended and the
resiliently deflected
position, the degree of efficiency for the conversion of the force provided by
the hydraulic
system into the (resulting) supporting force is inversely proportional to the
change in the force
provided by the hydraulic system. A force is provided by the hydraulic system
that counteracts
the (resilient) deflection of the support wheel. The extent to which or the
degree of efficiency
with which the force provided by the hydraulic system is converted into the
resulting
(substantially constant) supporting force is different for the extended and
the resiliently
deflected position. Both the force provided by the hydraulic system and the
degree of efficiency
of the force conversion for providing the supporting force thus differ for the
extended and the
resiliently deflected position. The changes in the force provided and the
degree of efficiency of
the conversion are inversely proportional. If, for example, the degree of
efficiency of the force
conversion decreases during the transition from the extended to the
resiliently deflected
position, the force provided by the hydraulic system increases such that in
total, i.e. as a result,
the supporting force provided at the support wheel device (resultant force)
remains
substantially the same.
During the transition between the extended and the resiliently deflected
position, a linear
(inverse) proportionality can be formed for the degree of efficiency in
relation to the change in
the force provided by the hydraulic system. Alternatively, a non-linear
proportionality can be
formed.
The carrier means can have a support arm, to which the support wheel is
connected and which
can be pivoted about a pivot axis into various pivot positions in relation to
the frame during the
transport journey such that the support wheel can be moved into the various
positions. The
extended position and the resiliently deflected positions are associated with
respective pivot
positions of the pivot arm about the pivot axis. The support wheel can be
connected to the
pivot arm via a support arm and a support arm holder. The reciprocity of the
force provided by
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the hydraulic system and the degree of efficiency of the force conversion
during the transition
between the various positions ensures that a torque equilibrium is maintained
for the support
arm on the pivot axis.
The hydraulic system can be connected to the pivot arm, forming a lever arm
between a
connection point, in which the hydraulic system is connected to the pivot arm,
and the pivot
axis. The force provided by the hydraulic system is applied to the pivot arm
via the lever arm,
which can be formed at least in sections in the longitudinal direction of the
pivot arm starting
from the pivot axis.
The hydraulic system can have a hydraulic cylinder, which is connected to the
pivot arm at the
connection point. In one embodiment, the force provided by the hydraulic
system is applied to
the pivot arm via the hydraulic cylinder, which in turn pivots about an
associated hydraulic
cylinder pivot axis spaced from the pivot axis, for example via a piston rod
that can be coupled
to the pivot arm and which is moved during operation together with the piston
held in the
hydraulic cylinder. The hydraulic cylinder thereby changes its position.
The degree of efficiency of the conversion of the force provided by means of
the hydraulic
system and applied to the lever arm of the carrier means is different due to
different angular
positions between the lever arm and a longitudinal direction of the hydraulic
cylinder. The
degree of efficiency of the conversion of the force applied or introduced to
the carrier means
via the lever arm depends on the angular position between the lever arm and
the longitudinal
direction of the hydraulic cylinder. In general, the greater the angle between
the lever arm and
the longitudinal direction of the hydraulic cylinder, the greater the degree
of efficiency of the
force conversion.
The hydraulic system can have a diaphragm accumulator or a piston accumulator.
The
respective accumulator can be in fluid connection with the hydraulic cylinder.
The accumulator
and hydraulic cylinder can form an open or a closed system depending on
operation. In the
case of a closed system, hydraulic fluid cannot flow back into the
(superordinate) hydraulic
system of the agricultural machine. If the carrier means moves into a
resiliently deflected
position, for example from the extended position, hydraulic fluid flows from
the hydraulic
cylinder, for example into the diaphragm accumulator, in which a gas volume is
compressed,
resulting in a higher back pressure such that the force provided by the
hydraulic system
increases, whereas the degree of efficiency of the conversion via the lever
arm to the carrier
means decreases due to the decrease in the angle.
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It can be provided that the support wheel can also be pivoted about a vertical
pivot axis. This
allows the support wheel to steer, especially when cornering.
In one embodiment, the supporting force provided by means of the support wheel
device can
be adjusted. For example, the hydraulic system can be configured to provide an
adjustable
basic or minimum counterforce that changes inversely proportionally to the
degree of efficiency
of the force conversion when moving between the positions of the support
wheel, starting from
the basic or minimum counterforce provided by the hydraulic system.
The work tools can comprise one or more of the following tools: soil
cultivation tool, spraying
tool, mowing tool, and seeding tool such as a seed unit.
Description of exemplary embodiments
Further exemplary embodiments are explained below with reference to figures of
a drawing.
In the figures:
Fig. 1 shows a schematic perspective view of an arrangement of work tools for
a seed drill;
Fig. 2 shows a schematic perspective view of an arrangement for a rotary
harrow;
Fig. 3 shows a schematic perspective view of an arrangement for a support or
transport
wheel device, wherein the support or transport wheel is arranged in a
retracted
position;
Fig. 4 shows a schematic perspective view of the arrangement shown in Fig. 3,
wherein the
support wheel is shown in an extended position;
Fig. 5 shows a schematic perspective view of the arrangement shown in Fig. 3,
wherein the
support wheel is shown in a partially deflected position; and
Fig. 6 shows a graphical representation of the force and displacement
components over
time on a hydraulic cylinder when the support wheel is deflected from an
extended
position.
Fig. 1 shows a schematic illustration of an arrangement with work tools 1 for
a seed drill, which
is coupled to a tractor (not shown) for work in the fields and for transport.
The various work
tools 1 are mounted in a plurality of rows transverse to the direction of
travel on a frame 2.
Such arrangements of work tools 1 on the frame 2 are known as such in various
embodiments.
Above the work tools 1, there is a support or transport wheel device 3 with a
carrier means 4,
which in the example shown is formed with a pivot arm 5, and a support or
transport wheel 6
arranged on the carrier means 4. The pivot arm 5 is connected to the support
wheel 6 and can
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be pivoted about a pivot axis 7, which is transverse to the direction of
travel. In order to pivot
the pivot arm 5, a hydraulic cylinder 8 is provided, which is coupled to the
pivot arm 5 at a
connection point 9, is pivotably mounted and, together with a diaphragm
accumulator (not
shown), is part of a hydraulic system 10, which is associated with the support
wheel device 3.
A lever arm 11 is formed by means of the connection between the hydraulic
cylinder 8 and the
pivot arm 5, which extends from the pivot axis 7 to the connection point 9.
In the illustration in Fig. 1, the support wheel 6 is arranged in a non-
working position above the
work tools 1, which for their part are arranged in a working position for work
in the fields. The
support wheel 6 is in this non-working position for work in the fields, for
example. In the event
of a transport journey of the agricultural machine, i.e. it being transported
by tractor on tracks
or roads, the work tools 1 are raised by means of associated frame elements of
the frame 2,
for example are pivoted sideways and upwards so as to create a gap or opening
beneath the
support wheel 6 in order to move the support wheel 6 by pivoting it into a
working position
(towards the ground) associated with the support wheel 6 such that the support
wheel is in
contact with the ground and thus supports the frame 2 with the work tools 1
accommodated
thereon for the transport journey. If the agricultural machine with the
arrangement shown in
Fig. 1 is connected to a tractor-side coupling device (not shown) in the usual
manner, for
example a three-point linkage, the frame 2 is supported, on the one hand, by
the tractor-side
coupling device and, on the other hand, by the support wheel device 3 during
the transport
journey with the work tools 1, in particular exclusively thereby.
Fig. 2 shows a schematic perspective illustration of an arrangement for a
(solo) rotary harrow,
in which work tools 1 are arranged on a gearbox 20. The rotary harrow can, for
example, be
combined with the arrangement of work tools 1 in such a way that an
agricultural machine with
an associated support wheel and a plurality of rows of work tools is created,
in which the rows
of work tools are arranged one behind the other in the direction of travel.
A connection can be established to the tractor-side coupling device (not
shown) via a machine-
side coupling device 21. The support wheel device 3 is also shown in a
retracted non-working
position in Fig. 2. Opposite sections of the tray 20 with the work tools 1 can
be pivoted sideways
and upwards for a transport journey on roads, as is known as such. The support
wheel device
3 can then be moved into an extended position towards the ground by means of
the hydraulic
cylinder 8 of the hydraulic system 10 in order to assume the support of the
frame 2 with the
work tools 1.
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Fig. 3 to 5 show schematic perspective views of an arrangement for the support
wheel device
3. The same reference numerals as in Fig. 1 and 2 are used in Fig. 3 to 5 for
identical features.
Fig. 3 shows a (completely) retracted position for the pivot arm 5 and the
support wheel 6
connected thereto via a support arm 30 and a support arm holder 31. The
support wheel 6 is
moved into different positions in relation to the frame 2 of the agricultural
machine by pivoting
the pivot arm 5. In the example shown, the carrier means 4 of the support or
transport wheel
device 3 is designed with a further pivot arm 5a, a further hydraulic cylinder
8a and a further
support arm 30a on both sides.
In the position shown in Fig. 3, a longitudinal direction of the hydraulic
cylinder 8 runs
substantially parallel to a connecting line between the pivot axis 7 and the
connection point 9.
In order to move the pivot arm 5 and thus the support wheel 6 into an extended
position (cf.
Fig. 4) and thus into the working position for the transport journey, the
hydraulic cylinder 8 is
extended such that the pivot arm 5 is pivoted about the pivot axis 7, whereby
the longitudinal
direction of the hydraulic cylinder 8 and the imaginary connecting line
between the pivot axis
7 and the connection point 9 assume an opening angle.
From the extended position shown in Fig. 4, the pivot arm 5 and thus the
support wheel 6 on
the support arm 30 can be moved into a contrastingly (partially) resiliently
deflected position,
which is shown in Fig. 5, for example when driving over a bump during the
transport journey.
The hydraulic cylinder 8 is shortened due to the (resilient) deflection. This
causes hydraulic
fluid to flow from the hydraulic cylinder 8 into an associated diaphragm
accumulator (not
shown), which is in fluid connection with the hydraulic cylinder 8 and forms a
closed system
therewith at least in this operating mode in such a way that no hydraulic
fluid can flow back out
of the closed system into the hydraulic system of the agricultural machine.
Due to the flow of
hydraulic fluid from the hydraulic cylinder 8 in the diaphragm accumulator, a
gas arranged on
the opposite side of the diaphragm of the diaphragm accumulator is compressed
there, which
in turn causes an increased back pressure. In this way, the force provided by
the hydraulic
system 10 with the hydraulic cylinder 8 and the diaphragm accumulator is
increased.
During the movement, the hydraulic cylinder 10 in turn pivots about an
associated hydraulic
cylinder pivot axis 7a that is spaced from the pivot axis 7.
The opposite is true during the transition from the extended position in Fig.
4 to the resiliently
deflected position in Fig. 5 in terms of the degree of efficiency of the
conversion of the force
provided by means of the hydraulic system and applied to the pivot arm 5 via
the hydraulic
CA 03223283 2023- 12- 18
cylinder, because the angle between the longitudinal direction of the
hydraulic cylinder 8 and
the imaginary connecting line between the connection point 9 and the pivot
axis 7 is reduced,
which reduces the force acting on the pivot arm 5. The force provided by the
hydraulic system
10, on the one hand, and the degree of efficiency of the force application, on
the other, are
thus inversely proportional. In this way, the supporting force provided by
means of the support
wheel device 3 during the transport journey remains substantially the same,
which
consequently means that the force load on the tractor-side coupling device
from the agricultural
machine remains substantially the same. As a result, the influence of the
agricultural machine
during the transport journey on the axle load of the tractor is substantially
constant, which
improves the driving safety for the machine combination of the tractor and
agricultural machine.
Fig. 6 shows this by means of a graphical representation. Force and
displacement components
are shown for the pivoting of the pivot arm 5. A curve 60 shows the time-
dependent cylinder
stroke on the hydraulic cylinder 8 during pivoting. A curve 61 shows the
displacement path of
the support wheel 6 as it resiliently deflects from the (completely) extended
position 62 to
deflection positions as time goes on. Finally, the curve 63 shows the force on
the hydraulic
cylinder 8 due to the interaction with the diaphragm accumulator in the closed
system during
pivoting. It follows that the curve 63 initially runs through a linear range
64 starting from the
extended position 62 during deflection.
The features disclosed in the above description, the claims and the drawing
can be of
importance both individually and in any combination for the realization of the
various
embodiments.
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