DE20306314U1 - Mowing machine adapted for attachment to three-point hitch for tractor is mounted on hinge with horizontal axis so that it can be swung up to vertical transport position - Google Patents

Abstract

The tractor (2) has a three-point hitch (3) with a horizontal hinge (6) at the side. A hydraulic actuator (7) may be used to lift the mowing machine from the horizontal position to the vertical portion and is connected to the main beam of the mowing machine (5). The mowing machine extends out to the side of the tractor when in its horizontal deployed portion and uses several cutters (4) rotating on vertical axes. The controls and drive pump for the actuator are mounted on the tractor.

Description

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"ßgsse & Busse ..Patent Attorneys

European Patent and Trademark Attorneys

Niemeyer Agrartechnik GmbH ™$j£* _: ⁰ ^^T^sTe

H.-Niemeyer-Straße 52 Dipl.-Ing. Egon Bünemann

D - 48477 Hörstel ^ipl.-lng. UI rich Pott

Dipl.-Ing. Kristiana Engelmann

Wholesale Ring 6

D-49084 Osnabruck

PO Box 1226

D-49002 Osnabruck

Telephone: 0541-586081 Fax: 0541-588164 mail® busse-patentanwaelte.de

22.04.2003 ldS/St-603029

mower

The invention relates to a mower with a controllable mower carrier according to the preamble of claim 1.

In known mowers, an actuation by means of a hydraulic cylinder is provided in the area of the mower carrier carrying the mowing tools in order to move it from a substantially horizontal working position to a respective high or intermediate position. This hydraulic cylinder controls not only the transport position with the mower carrier shifted to a 90° position, but also the intermediate positions required when mowing at the end of a swath, for example when reaching the edge of the field. In this phase, the mower carrier is pivoted upwards as required in accordance with the unevenness at the edge of the field. For this control process, a control part designed as a latch or similar assembly is integrated in the power flow between the mower carrier and the hydraulic cylinder in such a way that the pulling movement initiated at the piston rod and effective when pivoting upwards is stopped by a part of the piston rod running into a holding profile of the control part, and the mower carrier is thus held in the position reached. After that, by manual actuation, for example by means of

a traction cable, the position of the piston rod can be released by removing the latch and the mower carrier can be swivelled further or lowered. With this control using the latch, the hydraulic cylinder is permanently subjected to the hydraulic delivery pressure of the drive, so that disadvantageously high loads occur in the area of the control part and the hydraulic cylinder.

The invention addresses the problem of creating a mower whose mower carrier can be moved into repeatedly accessible lifting positions with little technical effort and without a latch engaging in the power flow, and the control enables a reduction in the component loads.

The invention solves this problem by a mowing machine with the features of claim 1. With regard to essential further embodiments, reference is made to claims 2 to 9.

The mower according to the invention has a functional unit with the shut-off device integrated in the hydraulic feed circuit of the hydraulic drive, which can be used in the manner of a programmable control for moving the mower carrier. The shut-off device is designed as a valve-working cylinder unit, which replaces the previously provided mechanical latches or similar control parts for the defined positioning of the piston rod of the hydraulic cylinder.

With this assembly, which has the shut-off device in the form of a spring-loaded shut-off valve of a known design, the construction of the mower in the area of the pivoting mower carrier is significantly simplified, the number of components in the power flow that are susceptible to wear due to mechanical tensile or compressive loads can be advantageously reduced and at the same time an advantageous

reductions in production costs.

By integrating the check valve as a controllable shut-off device into the delivery line in front of the piston-side working chamber of the hydraulic cylinder, a buffer effect is used by utilizing the fluid remaining in the piston-side working chamber when the check valve is closed, whereby a specification of one or more freely selectable "stop points" is made, which was previously limited to the effect of a mechanical lock, latch or similar. The fluid volume defined in the working chamber of the cylinder when the check valve is closed means that in a first control phase the fluid can expand when the piston rod is extended, and in the second control phase the fluid is only compressed up to a preselected defined volume when it is pushed in. This compression position of the working piston, which specifies a preselected swivel angle (e.g. the lifting position) of the mower carrier, can thus be stored as a stop point in the movement range of the hydraulic cylinder. If necessary, this defined stop position or the corresponding piston travel can be easily changed and adapted to the working conditions of the mower.

This creates an improved mower that can be quickly adjusted to the respective conditions in the area of the mower carrier at the edge of the field. Changing the working conditions, for example if a higher excavation is required when reaching the edge of the field, is possible with little effort, whereby the specification of fixed contact points in the form of contact profiles, which was previously required for a ratchet or similar control part, is no longer necessary and the design effort is thus reduced.

For further details and advantages of the invention, reference is made to the following description and the drawings, in which the mower according to the invention is explained in more detail using an exemplary embodiment. In the

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Show drawing:

Fig. 1 is a schematic diagram of a mower with the mower carrier shifted into the vertical transport position,

Fig. 2 a schematic diagram with the mower carrier in working position,

Fig. 3 the mower carrier according to Fig. 2 in an intermediate lifting position,

Fig.4

to Fig. 7 respective schematic diagrams of the mower carrier in different swivel positions (right side) and associated representation of the hydraulic feed circuit with different positions of the hydraulic cylinder (left side),

Fig. 8 is an enlarged detail view of the mower carrier with a schematic diagram of parts of the delivery line provided on the hydraulic cylinder,

Fig. 9 is a side view of a shut-off valve for the hydraulic circuit,

Fig. 10 is a sectional side view of the check valve according to Fig. 9 and

Fig. 11 is a schematic diagram similar to Fig. 8 with a prior art

Technology known control part in the form of a pawl on the hydraulic cylinder of the mower carrier.

Fig. 1 shows a mower, designated overall by 1, which is held on an agricultural tractor or similar towing vehicle 2 on a rear three-point frame 3 as a form of support. From the drawing plane, the mower 1 is fixed transversely to the direction of travel of the tractor 2 and, in the working position (Fig. 2), the mowing tools 4, which rotate about a vertical axis of rotation D, are shown. These mowing tools 4 are attached to a mower carrier, designated overall by 5, which in turn is supported on the three-point frame 3 in the area of an articulated connection 6 having an axis A running in the direction of travel. At a distance B from this articulated connection 6, a hydraulic cylinder 7 is provided, with which the mower carrier 5 can be pivoted about the support axis A.

Fig. 11 shows a design of the pivotable mower carrier 5 known from the prior art, in which the hydraulic cylinder 7 connected to a hydraulic drive 8 (Fig. 8) additionally acts on the mower carrier 5 by means of a control part 9 in the form of a latch or similar assembly, so that the latter can be controlled independently of the control unit 11 connected to the hydraulic circuit 10 (Fig. 8). The control part 9 is designed in such a way that the front area of the piston rod 12 of the hydraulic cylinder 7 rests on a contact profile 13 of the latch 9 and thus, for example, the contact position shown in Fig. 11 prevents further insertion movement (arrow N) of the piston rod 12. The raised position of the mower carrier 5, indicated by an angle H, is thus maintained even when hydraulic pressure is still present in the cylinder 7. When a pulling force Z is introduced, for example by means of a pulling cable operated by the operator, the pawl 9 is pivoted in the area of its support bearing 14 so that the piston rod 12 is released at the end and the mower carrier 5 can be moved into a predetermined lifting or lowering position.

This known ratchet control 9 is particularly necessary in order to control the mower 1 during the transition from a working position E ¹ parallel to the ground (Fig. 2) into the lifting position H (Fig. 3, Fig. 11) which is repeatedly required when the end of the swath is reached at the edge of the field.

In the mowing machine 1 designed according to the invention, instead of the mechanical control part 9, a shut-off device 17 is provided between the hydraulic drive 8 (Fig. 8) and the piston-side working chamber 15 (Fig. 4) of the hydraulic cylinder 7, which is integrated into the delivery line 16 and can be controlled by the operator in the tractor 2.

The shut-off device generally designated 17 in Fig. 4 to 7 (left side in each case) is integrated into the conveyor line 16 in particular in the form of a shut-off valve 18 (Fig. 9, Fig. 10) in such a way that a permanent closed position is predetermined by a closing part 19. The shut-off valve 18 can be unlocked directly by the operator in the area of the tractor 2 and/or by operating the control unit 11. In the latter embodiment, a connecting line (not shown in detail) is required from the control part 11 to the closing part 19.

In a practical embodiment, the shut-off valve 18 is provided in the region of the closing part 19 with a spring part 20 (Fig. 8, Fig. 9) which determines the closing position and which can be displaced or relaxed by a mechanical, hydraulic, electrical and/or magnetic counterforce (arrow G) so that the closing part 19 comes into a position which releases the conveying line 16 (flow arrow M, Fig. 10).

In Fig. 4, starting from the position of the components illustrated by a 90° angle F as the raised driving position of the mower 1, a corresponding starting position is illustrated on the left side in the area of the hydraulic cylinder 7 shown in a sectional schematic diagram. The mower 1 has

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this phase reaches its place of use and by actuating the shut-off valve 18 in the direction of arrow G the feed line 16 is released towards the piston-side working chamber 15 so that by means of the hydraulic drive 8 the piston rod 12 is displaced in a direction of arrow S such that at the end of this movement S the working position E' of the mower 1 shown in Fig. 5 is reached with the components aligned essentially parallel to the ground plane E.

Before the actual mowing process begins, the operator presets the mower 1 in such a way that the mower carrier 5 can be moved into the lifting position indicated by the angle H (Fig. 3) after completing a work cycle that forms a mowing swath, for example when the edge of the field is reached.

This excavation position H is also characterized in particular by a ground clearance T to the working plane E'. This ground clearance T is necessary in order to be able to overcome uneven surfaces or similar obstacles without impact, whereby in practice the respective distances T are selected in the range of, for example, 20 to 80 cm.

With the shut-off valve 18 used according to the invention, this ground clearance T or the excavation position H is generated by hydraulic position storage. Starting from the working position E' of the mower 1 shown in Fig. 5, a fluid pressure indicated by an arrow P is generated via the feed line 22 opening into the hydraulic cylinder 7 in the area of the ring-side working chamber 21. The shut-off valve 18 is held in the open position by the operator, for example (force G), and the piston rod 12 is thus displaced in the direction of the arrow S' while simultaneously discharging fluid from the total volume V in the working chamber 15.

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When the hydraulic cylinder 7 is actuated in this way, the lifting position H shown in Fig. 5, right-hand side, is reached and in this position the shut-off valve 18 is closed in the direction of the arrow G'. In this phase, the delivery pressure P of the delivery line 22 is switched off and the volume fraction V of the fluid remains in the piston-side working chamber 15. At the same time, the delivery line 22 is depressurized so that the fluid in the ring-side working chamber 21 can then be drained through the delivery line 22 in the direction of the arrow P'. This is brought about by a weight force K (Fig. 3) of the mower carrier 5 being applied in the area of the piston rod 12 and the piston rod 12 now moving under the effect of this actuating force until the piston 23 rests on the cylinder base 24 and the working position E' (Fig. 7, right-hand side) of the mower 1 is reached.

In this weight-loaded lowering phase of the mower carrier 5 assemblies, an internal expansion of the volume V of the fluid in the piston-side working chamber 15 takes place, which at the end of the lowering movement (working position E') occupies the volume V" in the working chamber 15 having a negative pressure.

With a distance arrow C in Fig. 6, which illustrates the movement of the working piston 23, it is clear that this stroke of the piston 23 can be freely selected and thus different angle or lifting positions H can be achieved. This allows the operator in the tractor 2 to carry out a continuous pre-setting of lifting positions H.

After reaching the working position according to Fig. 7, the mower 1 can carry out the intended processing and when the edge of the field is reached, at which the previously described lifting position H (Fig. 3) is required, a pressure switch P" is now carried out for the ring-side conveyor line 22 and the mower carrier 5 is compressed according to the defined compressible volume V" into the position shown in Fig. 6.

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The movement arrow C and the fluid volume V limiting the insertion movement are used to specify a "point of contact" for the piston 23, whereby this "programmable" point is to be regarded as the control target for the pivoted components of the mower carrier 5.

By depressurizing the conveyor line 22, the respective working position E' according to Fig. 7 can be repeatedly reached from the excavation position H, whereby the cycle described above with the buffer effect in the area of the hydraulic cylinder 7 is repeated as often as desired when the edge of the field is reached.

While the mower carrier 5 or the mower 1 is positioned in the working position E' and a mowing operation is being carried out, the components in the area of the hydraulic cylinder 7 are held in a floating position by correspondingly blocking the delivery lines 16 or 22, so that slight unevenness and inclination adjustments of the mower carrier 5 can be compensated. At the end of a working cycle, the mower carrier 5 can be swiveled up to the 90° position, whereby the check valve 18 is kept open accordingly when the delivery pressure P is applied.

In the schematic representation according to Fig. 8, a pulling device 24 is shown in the area of the integrated closing part 19 for controlling the shut-off valve 17 into the open position (arrow G) or for releasing the spring part 20, which can be actuated by the operator in the area of the tractor 2 so that the control shown by the arrow G takes place. In this embodiment, the spring part 20 is designed in particular as a compression spring 27 that can be displaced against a stop 25 and a control lever 26 of the shut-off valve 18. In the embodiment of the shut-off valve 17 according to Figs. 9 and 10, this has a spring part 20 designed as a spiral spring 27' in the area between the control lever 26 and the closing part 19.

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In a second embodiment for the pre-programmable setting of the mower carrier 5 to the lifting position H, it is provided that the mower carrier 5, starting from the 90° position shown in Fig. 4, is lowered in a first phase with the shut-off valve 18 open from its vertical transport position F by means of the pressure circuit for the piston-side delivery line 16 into the intended lifting position H (similar to Fig. 6).

In this position, the shut-off valve 18 is now closed so that when the ring-side feed line 22 is depressurized, the mower carrier 5 is lowered into the working position E ¹ by its weight force K (similar to Fig. 7). When the pressure is subsequently switched on for the ring-side feed line 22, the mower carrier 5 can be swiveled back into the previously set and repeatedly accessible lifting position H.

Claims (9)

1. Mower with a mower carrier ( 5 ) which is held on the rear three-point frame ( 3 ) of an agricultural tractor ( 2 ) or the like transversely to the direction of travel and has at least one mowing tool ( 4 ) which rotates around a vertical axis of rotation (D), which can be pivoted by means of a hydraulic cylinder ( 7 ) which engages at a distance (B) from its holder designed as an articulated connection ( 6 ) and is supported on the three-point frame ( 3 ) and on the mower carrier ( 5 ), wherein a respective working position (E) parallel to the ground or a lifting position (angle H) can be controlled by a hydraulic drive ( 8 ) connected to an operating unit ( 11 ) in the driver's cab ( 2 ), in such a way that the respective working position (E) and the lifting position (H) which repeats when a swath end is reached at the edge of the field are controlled by a hydraulic cylinder (7) in the area of the Mower carrier ( 5 ) can be influenced by a control part ( 9 ) in the form of a pawl or the like, which acts on the piston rod ( 12 ) and can be moved by the operator by means of a pull cable (Z) or the like, characterized in that instead of the control part ( 9 ) there is provided a shut-off device ( 17 ) which is integrated into the feed line ( 16 ) between the hydraulic drive ( 8 ) and the piston-side working space ( 15 ) of the hydraulic cylinder ( 7 ) and can be actuated by the operator. 2. Mower according to claim 1, characterized in that the shut-off member ( 17 ) is designed as a shut-off valve ( 18 ) which provides a permanent closed position (arrow G') on its closing part ( 19 ) and which can be unlocked directly by the operator and/or by means of an actuation of the operating unit ( 11 ). 3. Mower according to claim 1 or 2, characterized in that the shut-off member ( 17 ) or the shut-off valve ( 18 ) has a spring part ( 20 ) in the region of the closing part ( 19 ) which can be relaxed by mechanical, hydraulic, electrical and/or magnetic counterforce (G) for unlocking. 4. Mower according to one of claims 1 to 3, characterized in that to initiate movement on the piston rod ( 12 ) the check valve ( 18 ) can be brought into the open position (counterforce G), a ring-side feed line ( 22 ) of the hydraulic cylinder ( 7 ) can be switched to depressurized and after reaching the respective stroke position of the mower carrier ( 5 ) the closing part ( 19 ) of the check valve ( 18 ) can be automatically displaced into the blocking position. 5. Mower according to one of claims 1 to 4, characterized in that when the shut-off valve ( 18 ) is closed and the ring-side feed line ( 22 ) is depressurized, the mower carrier ( 5 ) can be lowered into the working position (E) by its weight (K). 6. Mower according to one of claims 1 to 5, characterized in that the mower carrier ( 5 ) can be moved from its ground-side working position (E) into a lifting position (H) repeatedly required in the working cycle when the check valve ( 18 ) is open, in this position the check valve ( 18 ) can be closed and when the check valve ( 18 ) is closed and the ring-side feed line ( 22 ) is depressurized, the mower carrier ( 5 ) can be lowered into the working position (E) by its weight (K) in such a way that when there is a subsequent pressure switch for the fluid in the ring-side feed line ( 16 ) and the check valve ( 18 ) is automatically closed, the mower carrier ( 5 ) can be pivoted back into the lifting position (H) and this lifting position (H) is defined by a fluid volume (V') remaining in the piston-side working chamber ( 15 ). 7. Mower according to one of claims 1 to 5, characterized in that the mower carrier ( 5 ) can be lowered from its vertical transport position (F) into the repeatedly required lifting position (H) by means of a pressure switch for the piston-side feed line ( 16 ) when the check valve ( 18) is open, the check valve (18 ) can be closed in this selected lifting position (H) and when the ring-side feed line ( 22 ) is depressurized, the mower carrier ( 5 ) can be lowered into the working position (E) by its weight (K) in such a way that with a subsequent pressure switch for the ring-side feed line ( 22 ) and the check valve ( 18 ) automatically closed, the mower carrier ( 5 ) can be pivoted back into the preset lifting position (H). 8. Mower according to one of claims 1 to 7, characterized in that the mower carrier ( 5 ) in the working position (E) has a floating position in the region of the hydraulic cylinder ( 7 ). 9. Mower according to one of claims 1 to 8, characterized in that a pulling device ( 24 ) which can be actuated by the operator of the tractor ( 2 ) is provided for controlling the shut-off valve ( 18 ) into the open position or for releasing the spring part ( 20 ) on the closing part ( 19 ).