ROTARY PLOUGH

Description

[0001] The present invention relates to a reversible plough according to the preamble of claim 1 or 2. Furthermore, the invention relates to a method for operating a reversible plough according to the preamble of claim 14.

[0002] A reversible plough of the types mentioned above comprises a headstock with attachment points for adapting the reversible plough to a towing vehicle, a plough frame that supports right-turning plough bodies on one side and left-turning plough bodies on the opposite side. The reversible plough can be rotated about a pivot axis relative to the headstock by means of a rotating device actuated by a rotating cylinder, with the rotating movement being limited by adjustable tilt stops. To control and execute the rotating movement, the piston chamber and, if applicable, an opposite annular chamber of the rotating cylinder are connected by supply lines to a first control unit and a first valve unit on the towing vehicle. The rotating cylinder pivots the plough frame of the reversible plough from one working position to the other via the pivot axis.In order to maintain sufficient clearance between the plough end and the ground in the half-turned position of multi-furrow reversible ploughs, the plough end is designed to be raised as high as possible.

[0003] Tilt stops are often designed as manually operated mechanical components such as spindles, cap nuts with stops, or similar devices for adjusting the tilt angle. The adjustment is complex, as it must be performed on both sides of the reversible plow. Furthermore, the tillage process must be interrupted to adjust the tilt angle by operating the tilt stops.

[0004] From GB 2 044 062 A a generic reversible plough is known which has two hydraulic cylinders assigned to the rotating cylinder, which serve to move the rotating cylinder beyond its dead center during a turning or swiveling process.

[0005] Another reversible plough of the type mentioned above is known from DE 86 31 539 U1. The reversible plough has a plough front frame with a plough frame rotatably mounted in the plough front frame, which can be pivoted from one working position to the other by means of a rotating device operated by a hydraulic cylinder. The working position of the plough front frame, and thus its position relative to the plough front frame, can be freely selected to adjust the inclination of the plough frame. For this purpose, the hydraulic cylinder is used as a piston-cylinder unit, in which a second piston is freely displaceably arranged on the piston rod of the piston unit. The two pistons, which can be displaced relative to one another, form three separate chambers that can be independently supplied with pressurized oil or closed off.To adjust the end positions of the turning device and thus the inclination of the plough frame relative to the front of the plough, the distance between the second piston and the ends of the cylinder or the distance between the pistons can be adjusted and fixed. This special design of the turning cylinder allows the operator to adjust the angle of inclination without having to leave the tractor. However, such a hydraulic cylinder is costly and prone to failure.

[0006] The invention is therefore based on the problem of designing and developing a reversible plough in such a way that a more cost-effective and reliable adjustment of the angle of inclination is possible.

[0007] The above problem is solved in a reversible plough according to the preamble of claim 1 or 2 by the features of the characterizing part of the respective claim, furthermore by corresponding method claims.

[0008] According to claim 1, a reversible plough is proposed which comprises a headstock with attachment points for adapting the reversible plough to a towing vehicle, a plough frame which carries right-turning plough bodies on one side and left-turning plough bodies on the opposite side and which is rotatable at least indirectly relative to the headstock about a rotation axis by means of a rotating device actuated by at least one rotating cylinder, wherein, to control a rotary movement, the annular chamber and piston chamber of the at least one rotating cylinder are connected by supply lines to a first control device and a first valve unit, wherein the rotary movement is limited by adjustable inclination stops. According to the invention, two hydraulic cylinders are provided to limit the rotary movement, forming the inclination stops, which limit the travel path of the rotating cylinder or the rotary movement generated thereby.

[0009] Alternatively, according to claim 2, a reversible plough is proposed which comprises a headstock with attachment points for adapting the reversible plough to a towing vehicle, a towing frame with a chassis arranged thereon, a plough frame which carries right-turning plough bodies on one side and left-turning plough bodies on the opposite side and which is rotatable about an axis of rotation by means of a rotating device actuated by a first and a second rotating cylinder, at least indirectly relative to the headstock or the towing frame, wherein, in order to control a rotary movement, the piston chamber of the at least one rotating cylinder is connected by supply lines to a first control unit and a first valve unit, wherein the rotary movement is limited by adjustable inclination stops directly or by means of further pendulum links connected to the rotating cylinders.According to the invention, two hydraulic cylinders forming the inclination stops are provided on the towing frame to limit the rotational movement, which limit the travel path of the rotary cylinder, the pendulum link or the rotational movement generated by the travel path.

[0010] The fundamental consideration is that the hydraulic cylinders, on the one hand, support the turning process caused by the rotating cylinder and, on the other hand, allow for a continuous adjustment of the angle of inclination.

[0011] The design of the tilt stops as hydraulic cylinders can help to standardize the connection of the rotary cylinder.

[0012] Preferably, the hydraulic cylinders can be designed as single-acting hydraulic cylinders. Alternatively, the hydraulic cylinders can be designed as double-acting hydraulic cylinders. The single-acting hydraulic cylinders can be designed as pressure cylinders or as tension cylinders.

[0013] According to one embodiment, the two hydraulic cylinders can be communicatively connected to one another by at least one common line, so that both hydraulic cylinders are subjected to the same pressure, wherein the at least one common line can be connected to a supply line of a hydraulic oil source by a second valve unit in order to bring about a pressure change in the at least one common line of the two hydraulic cylinders.

[0014] The hydraulic oil source can be, for example, a reservoir on the reversible plow or a hydraulic pump. Alternatively, the hydraulic oil source can be a hydraulic system of the towing vehicle. In the simplest case, the second valve unit can comprise a simple shut-off device such as a ball valve to allow the supply or discharge of hydraulic oil.

[0015] In a design with single-acting hydraulic cylinders that are connected to each other on the annular chamber side or piston chamber side by a common line, the hydraulic oil is forced from one hydraulic cylinder into the other during a rotary movement that causes the rotary cylinder to rest against the other hydraulic cylinder. The hydraulic oil quantity set in the common line determines the travel distance permitted by the respective hydraulic cylinder to which the rotary cylinder rests before the rotary movement is limited.

[0016] When using double-acting hydraulic cylinders, these are controlled on the piston chamber side and the annular chamber side, whereby the two piston chambers and the two annular chambers are each connected to each other by a common line, each with a supply line to the hydraulic oil source.

[0017] Preferably, a damping orifice can be installed upstream of the annular spaces of each of the two hydraulic cylinders. This can prevent damage to the hydraulic cylinders if the hydraulic oil is forced from one hydraulic cylinder into the other, unloaded hydraulic cylinder due to the contact of the rotary cylinder.

[0018] The relative position of the two hydraulic cylinders can be adjusted using an adjustment mechanism. The adjustment mechanism on each hydraulic cylinder is used for fine adjustment to compensate for manufacturing tolerances that can lead to different tilt settings when turning the reversible plough to the left or right due to the relative position of the hydraulic cylinders.

[0019] According to one embodiment, a second control unit can be provided for adjusting an angle of inclination, which is configured to control the second valve unit in order to alternately pressurize the annular chamber or the piston chamber of the rotary cylinder depending on the, in particular direct or indirect, contact of the rotary cylinder with the respective hydraulic cylinder and, depending on an increase in the angle of inclination to be adjusted, simultaneously pressurize the hydraulic cylinder. The pressure exerted when the rotary cylinder contacts the respective hydraulic cylinder is used as a signal to control the second valve unit by the second control unit. This embodiment enables side-independent adjustment of the inclination by controlling the hydraulic cylinders.

[0020] According to one embodiment, the second valve unit can comprise a control valve, which is designed as a shuttle valve, an electrically switchable valve, or a mechanically switchable valve. The valve is arranged in a common supply line connecting the piston chambers or the annular chambers of the hydraulic cylinders. Depending on the engagement of the rotary cylinder with the respective hydraulic cylinder, the control valve opens a supply line to the second control unit and closes a supply line to the unloaded hydraulic cylinder. This design of the second valve unit has the advantage that only the hydraulic cylinder that is in direct or indirect contact with the rotary cylinder moves.

[0021] According to an alternative embodiment, the second valve unit can comprise at least one switchable check valve which connects the hydraulic cylinders, which are interconnected by a common line, to a supply line to the second control unit, wherein both hydraulic cylinders are pressurized to the same pressure. The relative position of the two hydraulic cylinders to one another can be adjusted by a mechanical adjustment device. The hydraulic cylinders are preferably designed as pressure cylinders. In this embodiment, a control valve designed as a shuttle valve, electrically switchable valve, or mechanically switchable valve can be dispensed with. The switchable check valve can be activated when pressure is applied to the ring side or the piston side of the rotary cylinder.

[0022] According to a further development, the second valve unit can comprise a shut-off valve which is fluidically associated with the piston chamber or the annular chamber of the rotary cylinder. During the rotation process, the shut-off valve is pressurized with a control pressure from at least one of the two hydraulic cylinders. When a cut-off pressure preset on the shut-off valve is reached, the inflow into the piston chamber or the outflow from the annular chamber of the rotary cylinder is interrupted. For this purpose, the hydraulic oil of the hydraulic cylinder connected to the rotary cylinder can be directed through the control valve to the shut-off valve during a rotation process, so that the shut-off valve closes when the preset cut-off pressure is reached. The outflow of the hydraulic oil from the rotary cylinder or the inflow to the rotary cylinder is closed, thus ending the rotation.Depending on the preset cut-off pressure, the load can be distributed between the ring side of the rotary cylinder and the two hydraulic cylinders forming the tilt stops, so that the system is securely clamped.

[0023] According to a further development, the rotating device can comprise a lever arrangement by means of which the rotating cylinder is articulated to the plough frame.

[0024] In particular, the lever arrangement can be designed as a toggle lever, with a first lever which is pivotally connected to the plough frame and is articulated to a second lever, wherein the second lever can be designed as a piston rod of the rotary cylinder.

[0025] According to one embodiment, end stops can be arranged on the outside of the hydraulic cylinders, against which the first lever rests. The end stops can be mechanically adjustable to compensate for tolerances.

[0026] According to one embodiment, a first locking block can be assigned to the rotary cylinder, which connects the supply lines to the piston chamber and annular chamber of the rotary cylinder with supply lines of the second control unit. The second control unit can supply hydraulic oil to the piston chamber of the rotary cylinder via one of the supply lines to adjust the inclination, so that the rotary cylinder extends, while hydraulic oil is diverted from the annular chamber of the rotary cylinder and the hydraulic cylinder to which the rotary cylinder rests, to the second control unit, thereby retracting the hydraulic cylinder. This causes the angle of inclination to decrease.To increase the angle of inclination, the annular chamber and the hydraulic cylinder to which the rotary cylinder is connected are supplied with hydraulic oil via one of the supply lines of the second control unit, while hydraulic oil can flow out of the piston chamber of the rotary cylinder via the other supply line of the second control unit. The rotary cylinder retracts while the corresponding hydraulic cylinder extends. The control valve, designed as a shuttle valve, electrically switchable valve, or mechanically switchable valve, ensures that only the hydraulic cylinder to which the rotary cylinder is connected is moved for inclination adjustment.

[0027] In particular, the tilt stops designed as double-acting hydraulic cylinders can be assigned a second locking block which connects the hydraulic cylinders to the second control unit.

[0028] According to a further development, a frame pivoting device for pivoting in and out can engage the plough frame, which can be controlled as a function of the pressure caused by the rotation cylinder being in contact with one of the hydraulic cylinders, in order to pivot the plough frame in before the turning process is carried out by the rotation cylinder of the frame pivoting cylinder and to pivot it out after the turning process has been carried out by the rotation cylinder being in contact with the other hydraulic cylinder. This can ensure that the plough frame is first pivoted in when the rotation cylinder is in contact with one of the hydraulic cylinders in order to avoid a collision with the ground before the turning process is carried out by controlling the rotation cylinder. At the end of the turning process, the rotation cylinder is in contact with the other hydraulic cylinder, so that this is used as a signal to trigger the pivoting out in order to transfer the plough frame into its working position.

[0029] The object stated at the outset is achieved by a method for operating a reversible plough according to claim 13.

[0030] According to claim 13, a method for operating a reversible plough is proposed, which comprises a headstock with attachment points for adapting the reversible plough to a towing vehicle, a plough frame which carries right-turning plough bodies on one side and left-turning plough bodies on the opposite side and which is rotated about a rotation axis relative to the headstock by a rotating device actuated by a rotating cylinder, wherein the annular chamber and piston chamber of the rotating cylinder are connected to a first control unit and a first valve unit for controlling a rotary movement, wherein the rotary movement is limited by adjustable inclination stops, wherein two hydraulic cylinders forming the inclination stops are provided to limit the rotary movement and by means of which the travel path of the rotating cylinder is limited. Reference may be made to the embodiments and advantages of the reversible plough according to the invention.

[0031] For example, to adjust an angle of inclination, a second valve unit and a second control device can be used, which are designed to alternately pressurise the annular chamber or the piston chamber of the rotary cylinder depending on the direct or indirect contact of the rotary cylinder with the respective hydraulic cylinder and, depending on an increase or rise in the angle of inclination to be set, to simultaneously pressurise the hydraulic cylinder. Two hydraulic cylinders are provided to limit the rotary movement and limit the travel path of the rotary cylinder, wherein to adjust the inclination, a second valve unit and a second control device are provided, which are controlled to alternately pressurise the annular chamber or the piston chamber of the rotary cylinder and the piston chamber of the respective hydraulic cylinder depending on the contact of the rotary cylinder with the respective hydraulic cylinder.

[0032] According to one embodiment, a frame pivoting device for pivoting in and out can engage the plough frame, which is controlled as a function of a pressure caused by the rotation cylinder being in contact with one of the hydraulic cylinders in order to pivot the plough frame in before the turning process is carried out by the rotation cylinder and to pivot it out after the turning process has been carried out with the rotation cylinder being in contact with the other hydraulic cylinder.

[0033] The present invention is explained in more detail below with reference to embodiments shown in the drawings.

[0034] They show: Fig. 1 a side view of a reversible plough; Fig. 2 a perspective partial view of a mounting tower of the reversible plough; Fig. 3 a first circuit diagram for controlling a rotational movement and setting an inclination angle; Fig. 4 a further circuit diagram for controlling a rotational movement and setting an inclination angle; Fig. 5 a circuit diagram with inclination stops designed as double-acting hydraulic cylinders; Fig. 6 a circuit diagram with inclination stops designed as single-acting hydraulic cylinders and a shuttle valve; Fig. 7 a circuit diagram according to Fig. 6 with hydraulic cylinders arranged as pulling cylinders; Fig. 8 a circuit diagram according to Fig. 6 with a mechanically switchable shuttle valve; Fig. 9 a circuit diagram according to Fig. 6 with an electrically switchable shuttle valve. Fig. 10 an alternative design according to Fig. 2 and Fig. 6Fig. 11 a perspective view of another reversible plough; Fig. 12 a perspective partial view of a revolving mechanism from Fig. 11

[0035] Figure 1shows a side view of a reversible plough 1. This is a mounted reversible plough, comprising a headstock 2 with coupling or attachment points 3 for adapting the reversible plough 1 to a towing vehicle (not shown). The reversible plough 1 is coupled to a three-point linkage of the towing vehicle pulling and carrying the reversible plough 1. The attachment point 3 forms a pivot axis 11 about which the reversible plough 1 can be pivoted in and out in the vertical direction. The reversible plough 1 further comprises a plough frame 4, which carries right-turning plough bodies 5 on one side and left-turning plough bodies 5, 5' on the opposite side. The three-point linkage of the towing vehicle allows the reversible plough 1 to be moved from a lowered working position into a raised position for transport or for turning the reversible plough 1.To turn the reversible plough, the plough frame 4 can be rotated relative to the attachment head 2 about a pivot axis 6 by a pivot device 8, which is actuated by a pivot cylinder 7 and is designed as a toggle lever arrangement. The plough frame 4 can be pivoted through an angle of approximately 180° from a right-turning to a left-turning position. For this purpose, the pivot cylinder 7 is pivotally connected to the attachment head 2 at one end at pivot point 9 and is pivotally connected to the plough frame 4 at its other end at pivot point 13 by a first lever 12, spaced from the pivot axis 6, as shown in FIG. Fig. 2shown. Several right- and left-turning ploughing tools 5, 5' are attached to the plough frame 4, spaced one behind the other. Each right- and left-turning ploughing tool 5, 5' forms a fastening unit that is preferably symmetrical in design with respect to a longitudinal axis 10 of the plough frame 4. In the working position, the reversible plough 1 is pulled through the soil in the direction of travel. The "direction of travel" refers to the forward direction of travel of the towing vehicle pulling the reversible plough 1 into the working position.

[0036] In Fig. 2a perspective partial view of the attachment headstock 2 of the reversible plough 1 is shown. In order to rotate the plough frame 4 safely into the opposite working position, i.e. from a right-turning to a left-turning position or vice versa, and secondly to prevent excessive rotation, adjustable inclination stops 16 are arranged on both sides of the rotary cylinder 7, which has a piston rod 14 and a cylinder 15. The inclination stops 16 are designed according to the invention as hydraulic cylinders 17. In particular, the hydraulic cylinders 17 are designed as single-acting hydraulic cylinders 18 or double-acting hydraulic cylinders 19. In the present case, the hydraulic cylinders 17 are designed as pulling cylinders with a stop hook arranged thereon, on which the lever 12 rests or strikes in the end position of the rotary movement. Alternatively, in Figure 10Single-acting hydraulic cylinders 18, designed as cost-effective plunger cylinders, are arranged on the attachment tower 2. With their protruding pistons, these cylinders directly form the stop surface of the tilt stops 16, against which the lever 12 rests or strikes in the end position of the rotational movement. In the rotating device 8 designed as a toggle lever arrangement, the piston rod 14 of the rotating cylinder 7 forms the second lever, which is connected to the first lever 12 at the articulation point 13.

[0037] Figure 11shows a reversible plough 1 in a perspective view from the rear. This is a semi-mounted reversible plough, comprising a headstock 2 with coupling or attachment points 3 for adapting the reversible plough 1 to a towing vehicle (not shown). The reversible plough 1 is coupled to a three-point linkage of the towing vehicle pulling and carrying the reversible plough 1. The attachment point 3 is connected via a steering axle 51 to a towing frame 48, which can be pivoted laterally, and at the end of the towing frame to a chassis 50. The pivot axis 11 in the towing frame forms a joint around which the front area of ​​the reversible plough 1 can be raised and lowered by the towing vehicle in vertical alignment with the headstock. The lifting and lowering of the rear area of ​​the reversible plough 1 is carried out by the correspondingly designed chassis 50.The reversible plough 1 further comprises a plough frame 4, which supports right-turning plough bodies 5 on one side and left-turning plough bodies 5, 5' on the opposite side. The three-point linkage of the towing vehicle and the chassis 50 allow the reversible plough 1 to be moved from a lowered working position to a raised position for transport or for turning the reversible plough 1. To turn the reversible plough, the plough frame 4, which is connected to the lever 12, can be rotated relative to the towing frame 48 about a pivot axis 6 by a pivot device 8 actuated by a first and a second pivot cylinder 7. Another pivot joint with a pivot axis 6' is arranged at the rear of the chassis. The plough frame 4 can be pivoted through an angle of approximately 180° from a right-turning to a left-turning position.A central position of approximately 90° represents the transport position, in which the plough frame 4 with the plough bodies 5, 5' are arranged above the chassis. To generate the rotary movement, two rotary cylinders 7 are each pivoted at one end to the lever 12 at a pivot point 9 and at the other end are pivotally connected to the draw frame 48 at a pivot point 13 by means of further pendulum links 49, which abut the draw frame 48 on the respective turning side of the plough frame 4, at a distance from the axis of rotation 6, as shown in FIG. Fig. 12shown. The pendulum links 49 are arranged by means of additional pendulum joints to the right and left of the rotation axis 6 in the vicinity of the latter on the rotating device 8. The pendulum link 49, which is unloaded in the respective working position of the reversible plough 1, is dragged upwards around the pendulum joint 52 by the rotating cylinder 7, which is extended to its end position, and guides the extended rotating cylinder 7 approximately parallel to the lever 12 in order to avoid collisions. Several right- and left-turning ploughing tools 5, 5' are attached to the plough frame 4 at a distance one behind the other. One right- and one left-turning ploughing tool 5, 5' each form a fastening unit that is preferably symmetrical in design with respect to a longitudinal axis 10 of the plough frame 4. In the working position, the reversible plough 1 is pulled through the ground in the direction of travel. The direction of travel refers to the forward direction of travel of the towing vehicle pulling the reversible plough 1 into the working position.

[0038] In Fig. 12a perspective partial view of the attachment headstock 2 of the reversible plough 1 is shown. The rotating cylinders are designed with a preferably telescopic piston rod 14 and a cylinder 15. In order to rotate the plough frame 4 safely into the opposite working position, i.e. from a right-turning to a left-turning position or vice versa, and secondly to prevent excessive rotation, adjustable inclination stops 16 are arranged on both sides of the drawbar end of the rotating cylinders 7 or on the pendulum links 49, which are each connected to the rotating cylinders 7 via the pivot points 13. The inclination stops 16 are supported at the lower end against an abutment of the drawbar 48 and are preferably arranged in a V-shape relative to one another. They come into effect in the retracted end position of the rotating cylinders 7 or the lowest position of the pendulum links 49. According to the invention, the inclination stops 16 are designed as hydraulic cylinders 17.In particular, the hydraulic cylinders 17 are designed as single-acting hydraulic cylinders 18 or double-acting hydraulic cylinders 19. In the present case, the hydraulic cylinders 17 are shown as cost-effective, single-acting hydraulic cylinders 18, on which the respective pendulum links 49 and thus indirectly the rotary cylinders 7 rest or strike in the end position of the rotary movement.

[0039] The representation in Fig. 3shows a first circuit diagram for controlling a rotary movement of the plow frame 4 by the rotary cylinder 7 and for setting an angle of inclination. Setting or adjusting the angle of inclination during a work operation is necessary in order to override or change a preset inclination stop, in particular to leave the last furrow in a field less deep. This procedure facilitates later maneuvering during subsequent work operations. Especially in the area of ​​drainage ditches, it is important not to plow the adjacent furrow too deeply in order not to destroy the trench structure and to prevent soil from falling into the ditch. Overriding the stop also enables parallel insertion of the plow, which leads to a straight headland.

[0040] To control a rotary movement, the annular chamber 21 and piston chamber 22 of the rotary cylinder 7 are connected by lines 23, 24 to a first control unit 25 and a first valve unit 26. The pressurization of the annular chamber 21 or piston chamber 22 of the rotary cylinder 7 through the lines 23, 24 leads to the rotation of the plough frame 4. In this case, the rotary cylinder 7 moves, depending on the direction of rotation, against one of the hydraulic cylinders 17 designed as tilt stops 16, ie rests against it. The rotary cylinder 7 can be indirectly, as in Fig. 2 shown, or directly against the hydraulic cylinder 17.

[0041] The hydraulic cylinders 17 are designed as single-acting hydraulic cylinders 18, here arranged as pull cylinders. The hydraulic cylinders 18 are communicatively connected to one another by a common line 27, so that both hydraulic cylinders 18 are subjected to the same pressure. The at least one common line 27 is connected by a second valve unit 28 to a supply line 29 with a hydraulic oil source, which here and preferably is designed as a second control unit 30, in order to bring about a pressure change in the at least one common line 27 of the two single-acting hydraulic cylinders 18. For this purpose, the second valve unit 28 comprises a shut-off body 31, which in the illustrated embodiment is designed as a pilot-operated check valve 37. The shut-off body 31 connects the common line 27 to the supply line 29. In the simplest case, the shut-off body 31 can be designed as a ball valve.

[0042] In this design as single-acting hydraulic cylinders 18, which are connected to each other on the annular chamber side or on the piston chamber side by the common line 27, the hydraulic oil is pressed from one hydraulic cylinder 18 into the other hydraulic cylinder 18 during a rotary movement of the plow frame 2, which leads to the rotary cylinder 7 being in contact with one of the hydraulic cylinders 18 and thus to the retraction of this hydraulic cylinder 18. The amount of hydraulic oil set in the common line 27 determines the travel distance permitted by the respective hydraulic cylinder 18, against which the rotary cylinder 7 is in contact, before the rotary movement is limited. This is achieved by the unloaded hydraulic cylinder 18 being fully retracted, whereby a column of hydraulic oil remains in the hydraulic cylinder 18 loaded by the contact of the rotary cylinder 7, which prevents further rotation about the rotation axis 6 at the articulation point 20.The single-acting hydraulic cylinders 18 can each be assigned an orifice 32, which slows down the flow of hydraulic oil from the loaded to the unloaded hydraulic cylinder 18 in order to dampen the rotation process in the end positions.

[0043] The second valve unit 28 can comprise a shut-off valve 33, which is fluidically connected to the piston chamber 22 or the annular chamber 21 of the rotary cylinder 7. When the rotary cylinder 7 rests against one of the two hydraulic cylinders 18 during the rotation process, the shut-off valve 33 is pressurized with pressure from the common line 27 and, depending on the arrangement of the shut-off valve 33, can interrupt the inflow to the piston chamber 22 or the outflow from the annular chamber 21 of the rotary cylinder 7 upon reaching a shut-off pressure preset on the shut-off valve 33.

[0044] In the illustrated embodiment according to Fig. 3the shut-off valve 33 connects the annular chamber 21 of the rotary cylinder 7 with the first valve unit 26 and the first control unit 25. During a rotation process, the piston chamber 22 is pressurized with hydraulic oil from the first control unit 25 via the supply line 23. The hydraulic oil in the annular chamber 21 flows back to the first control unit 25 via the shut-off valve 33 and the line 24. The rotary cylinder 7 can thus extend and rests against one of the two hydraulic cylinders 18, loading it. The hydraulic oil from the loaded hydraulic cylinder 18 flows through the common line 27 to the unloaded hydraulic cylinder 18 until the latter is fully retracted. The hydraulic oil is passed on through the supply line 29 to actuate the shut-off valve 33. The check valve 37 blocks the supply line 29 to prevent any flow out of the common line 27.The shut-off valve 33 closes the line 24 from the first control unit 25 when a preset pressure has been built up in the common line 27. This allows the flow of hydraulic oil to the piston chamber 22 of the rotary cylinder 7 to be interrupted by the first control unit 25, thus ending the rotation process.

[0045] For rotation in the opposite direction, the annular chamber 21 is pressurized with hydraulic oil from the first control unit 25 via line 24. The hydraulic oil in the piston chamber 22 flows back to the first control unit 25 via line 23. This allows the rotary cylinder 7 to retract. The relief of the hydraulic cylinder 18 by the retracting rotary cylinder 7 leads to a drop in the control pressure at the shut-off valve 33, causing it to open.

[0046] To adjust or adjust the angle of inclination, hydraulic oil is fed from the second control unit 30 through the supply line 29 at connection 36 into the annular chamber 21 of the rotary cylinder 7, causing the latter to retract. At the same time, the hydraulic oil drain from the piston chamber 22 is fed to connection 34 of the second control unit 30 via a first locking block 38, which is enclosed by the second valve unit 28, so that the loaded rotary cylinder 7 retracts. The amount of hydraulic oil in the common line 27 between the hydraulic cylinders 18 is increased, causing both hydraulic cylinders 18 to retract.

[0047] For an opposite adjustment of the tilt angle, hydraulic oil is fed from the second control unit 30 through a supply line 35 at connection 34 into the piston chamber 22 of the rotary cylinder 7, while the hydraulic oil flows out of the annular chamber 21, causing the cylinder to extend. The hydraulic oil quantity in the common line 27 between the hydraulic cylinders 18 is reduced via the pilot-operated check valve 37 by flowing to connection 36, causing the hydraulic cylinders 18 to retract due to the load from the adjacent rotary cylinder 7.

[0048] According to one embodiment, end stops 39 can be arranged on the outside of the hydraulic cylinders 18, against which the first lever 12 is supported. The end stops 39 can be designed to be mechanically adjustable by an adjustment mechanism 40 in order to compensate for manufacturing tolerances.

[0049] In Fig. 4Another circuit diagram for controlling a rotary movement and adjusting the angle of inclination is shown. This embodiment differs in that the rotary movement is switched off on the annular chamber side of the rotary cylinder 7. The control of the shut-off valve 33 is carried out according to the Fig. 3 described procedure depending on the pressure in the common line 27. Here, the shut-off valve 33 controls the outflow of hydraulic oil from the piston chamber 22 of the rotary cylinder 7.

[0050] The representation in Fig. 5 shows a circuit diagram with tilt stops 16 designed as double-acting hydraulic cylinders 19. The control for switching off the rotary movement is carried out according to the embodiment according to Fig. 4on the annular chamber side of the rotary cylinder 7 by the shut-off valve 33. According to this embodiment, the second valve unit 28 comprises, instead of the shut-off body 31 designed as a pilot-operated check valve 37, a shut-off body 31 designed as a second locking block 42. The second locking block 42 connects the common line 27, which connects the annular chambers of the double-acting hydraulic cylinders 19 in a communicating manner with one another, and a further common line 41, which connects the piston chambers of the double-acting hydraulic cylinders 19 in a communicating manner with one another, with the connections 34, 36 of the second control unit 30. To adjust the angle of inclination, the hydraulic oil quantity of the hydraulic cylinders 19, which are connected in a communicating manner by the common lines 29, 41 on the piston chamber side and the annular chamber side, is changed.

[0051] In Fig. 6A circuit diagram is shown with tilt stops 16 designed as single-acting hydraulic cylinders 18 and a shuttle valve 43 designed as a control valve. The essential difference from the previously described embodiments is that the shuttle valve 43 allows for side-independent adjustment of the tilt angle. Separate supply lines 44, 45 lead from the shuttle valve 43 to the respective hydraulic cylinder 18, which, in the present case, connect the respective piston chamber of the hydraulic cylinder 18 arranged as a pressure cylinder with the shuttle valve 43.

[0052] During the inclination adjustment, hydraulic oil is fed into the piston chamber 22 of the rotary cylinder 7 by the second control unit 30 via the connection 34, while at the same time oil flowing out of the annular chamber 21 and from the single-acting hydraulic cylinder 18 loaded by the adjacent rotary cylinder 7 is fed to the connection 36 of the second control unit, so that the rotary cylinder extends and the loaded hydraulic cylinder 18 retracts.

[0053] When adjusting the inclination in the other direction, the hydraulic oil is fed via the connection 36 into the loaded hydraulic cylinder 18 and the annular chamber 21 of the rotary cylinder 7, so that the rotary cylinder 7 retracts and the loaded hydraulic cylinder 18 extends.

[0054] The shuttle valve 43 ensures that only the hydraulic cylinder 18 moves which is loaded by the directly or indirectly adjacent rotary cylinder 7.

[0055] The representation in Fig. 7shows a circuit diagram according to Fig. 6 with hydraulic cylinders 18 arranged as pulling cylinders. The separate supply lines 44, 45 connect an annular chamber of the respective hydraulic cylinder 18 with the shuttle valve 43. The function otherwise corresponds to that of the embodiment according to Fig. 6 .

[0056] In the Fig. 8 and 9 There are two further circuit diagrams according to Fig. 6 In these further embodiments, according to Fig. 8 instead of the shuttle valve a mechanically switchable valve 46 and according to Fig. 9An electrically switchable valve 47 is provided. When the control valve is designed as a mechanically switchable valve 46, the respective switching can be controlled by the rotary movement of the rotating device 8, which is designed as a toggle lever arrangement. When the control valve is designed as an electrically switchable valve 47, the respective switching can also be coupled to the rotary movement of the rotating device 8.

[0057] In Fig. 13 is a circuit diagram similar to Fig. 6 , but adapted to the execution according to Fig. 11 and 12, also shown with tilt stops 16 designed as single-acting hydraulic cylinders 18 and a shuttle valve 43 designed as a control valve. The essential difference from the previously described embodiments is that two single-acting rotary cylinders 7 are now provided in conjunction with pendulum links 49, which are connected to the lever arm 12 at the end of the cylinder via pivot points 9. Here, too, the shuttle valve 43 can be used to adjust the angle of inclination independently of either side. Separate supply lines 44, 45 lead from the shuttle valve 43 to the respective hydraulic cylinder 18, which in the present case connect the respective piston chamber of the hydraulic cylinder 18 arranged as a pressure cylinder with the shuttle valve 43.

[0058] During tilt adjustment, the second control unit 30 directs hydraulic oil via port 36 into the piston chamber of the hydraulic cylinder 18, which is loaded by the adjacent rotary cylinder 7 and the corresponding pendulum link 49. In order to direct hydraulic oil flowing from the single-acting hydraulic cylinder 18 to port 36 of the second control unit, a shut-off body 31 designed as a pilot-operated check valve 31 is opened by means of a pressure signal from the second control unit, so that the hydraulic oil can flow through line 36 into the second control unit 30 and the loaded hydraulic cylinder 18 retracts.

[0059] The shuttle valve 43 ensures that only the hydraulic cylinder 18 that is loaded by the directly or indirectly connected rotary cylinder 7 or its pendulum link 49 moves. The other, unloaded rotary cylinder 7, in its extended position, pulls its connected pendulum link 49 upwards, so that the other hydraulic cylinder 18 is unloaded and its hydraulic oil supply is blocked by the shuttle valve 43.

[0060] When adjusting the inclination in the other direction, the hydraulic oil is fed into or out of the other, oppositely loaded hydraulic cylinder 18 via the connection 36, so that here too the hydraulic cylinder 18 loaded by the retracted rotary cylinder 7 and the pendulum link 49 extends or retracts.

[0061] To control a rotary movement, the piston chamber 22 of the retracted rotary cylinder 7 is connected to a first control unit 25 via line 23. The pressurization of the piston chamber 22 of the rotary cylinder 7 through the lines 23 causes the plough frame 4 to rotate about the rotation axis 6. Depending on the direction of rotation, the rotary cylinder 7 moves over a dead center. The second, extended rotary cylinder 7 then strikes with the pendulum link against the unloaded hydraulic cylinder 18 designed as an inclination stop 16. Due to the actuating force of the rotary cylinder 7 pressurized by the line 23 and subsequently due to the dead weight of the plough frame 4, the hydraulic oil of the previously unloaded rotary cylinder escapes through the line 24 into the other, open connection of the first control unit 25 until the previously unloaded rotary cylinder 7 rests in the retracted end position by means of its pendulum link 49 on the opposite inclination stop 16.

[0062] To rotate in the opposite direction, the piston chamber of the now retracted rotary cylinder is pressurized with hydraulic oil from the first control unit 25 via line 24. The turning process then occurs in exactly the opposite way to the previously described turning process. The hydraulic oil in the piston chamber 22 flows back to the first control unit 25 via line 23. This allows the opposite rotary cylinder 7 to retract after passing the dead center. The relief of the hydraulic cylinder 18 by the rotary cylinder 7, which is then pulled along by means of the pendulum link 49, leads to a drop in the locking pressure at the shuttle valve 43, so that this switches accordingly.

[0063] Turning the plough and adjusting the inclination as described in Figure 11-13can be carried out independently of each other. Furthermore, instead of the shuttle valve 43, separate control of the stops designed as hydraulic cylinders 17, 18 is also possible by means of a third control unit (not shown) in addition to the second control unit 30. List of reference symbols 1 reversible plough 33 Shut-off valve 2 Extension tower 34 Connection 3 Attachment point 35 supply line 4 Plough frame 36 Connection 5 Plough body 37 check valve 5' Plough body 38 First barrier block 6 axis of rotation 39 End stop 7 rotary cylinder 40 Adjustment mechanism 8 Rotating device 41 Line 9 articulation point 42 Second barrier block 10 Longitudinal axis 43 shuttle valve 11 Swivel axis 44 supply line 12 lever 45 supply line 13 articulation point 46 Mechanically switchable valve 14 piston rod 47 Electrically switchable valve 15 cylinder 48 Tension frame 16 Tilt stop 49 pendulum handlebar 17 hydraulic cylinder 50 chassis 18 Single-acting hydraulic cylinder 51 Steering axle 19 Double-acting hydraulic cylinder 52 pendulum joint 20 articulation point 21 Annular chamber 22 piston chamber 23 Line 24 Line 25 First control unit 26 First valve unit 27 Joint management 28 Second valve unit 29 supply line 30 Second control unit 31 Shut-off body 32 aperture

Claims

1. A reversible plough (1), comprising a headstock (2) with attachment points (3) for adaptation of the reversible plough (1) to a traction vehicle, a plough frame (4), which on one side carries right-turning plough bodies (5) and on the opposite side carries left-turning plough bodies (5') and is pivotable about a pivot axis (6) by a pivoting device (8) actuated by at least one pivot cylinder (7) at least indirectly relative to the headstock (2) or to a traction frame, wherein for controlling a pivot movement the annular chamber (21) and / or the piston space (22) of the at least one pivot cylinder (7) are connected by supply lines (23, 24) to a first control device (25) and a first valve unit (26), wherein the pivot movement is limited by adjustable inclination stops (16), characterised in that for limiting the pivot movement two hydraulic cylinders (17) forming the inclination stops (16) are provided on the headstock (2), which limit the travel of the pivot cylinder (7) or the pivot movement thereby created.

2. The reversible plough (1), comprising a headstock (2) with attachment points (3) for adaptation of the reversible plough (1) to a traction vehicle, a traction frame (48) with chassis (50) arranged their on, a plough frame (4), which on one side carries right-turning plough bodies (5) and on the opposite side carries left-turning plough bodies (5') and is pivotable about a pivot axis (6) by a pivot device (8) actuated by a first and a second pivot cylinder (7) at least indirectly relative to the headstock (2) or the traction frame (48), wherein for controlling a pivot movement the piston space (22) of the at least one pivot cylinder (7) is connected by supply lines (23, 24) to a first control device (25) and a first valve unit (26), wherein the pivot movement is limited by adjustable inclination stops (16) directly or by means of further swing levers (49) connected to the pivot cylinders, characterised in that for limiting the pivot movement two hydraulic cylinders (18) forming the inclination stops (16) are provided on the traction frame (48), which limit the travel of the pivot cylinder (7), of the swing levers (49) or the pivot movement generated by the travel.

3. The reversible plough (1) according to Claim 1 or 2, characterised in that the hydraulic cylinders (17) are embodied as single-acting hydraulic cylinders (18) or double-acting hydraulic cylinders (19).

4. The reversible plough (1) according to Claims 1 to 3, characterised in that the two hydraulic cylinders (17, 18, 19) are inter-communicatingly connected by at least one common line (27, 41), so that both hydraulic cylinders (17, 18, 19) are subjected to the same pressure, wherein the at least one common line (27, 41) is connectable through a second valve unit (28) to a supply line (29) of a hydraulic oil source in order to bring about a pressure change in the at least one common line (27, 41) of the two hydraulic cylinders (17, 18, 19).

5. The reversible plough (1) according to any one of the Claims 1 to 4, characterised in that the position of the two hydraulic cylinders (17, 18, 19) relative to one another is adjustable in each case by an adjusting mechanism (40).

6. The reversible plough (1) according to any one of the Claims 3 to 5, characterised in that for adjusting an inclination angle a second control device (30) is provided, which is equipped in order to control the second valve unit (28) in order to alternately pressurise the annular chamber (21) or the piston space (22) of the pivot cylinder (7) depending on the pivot cylinder (7) lying against the respective hydraulic cylinder (17, 18, 19) and at the same time pressurise the hydraulic cylinder (17, 18, 19) depending on an increase of the inclination angle to be adjusted.

7. The reversible plough (1) according to Claim 6, characterised in that the second valve unit (28) comprises a control valve which is embodied as a change-over valve (43), an electrically switchable valve (47) or a mechanically switchable valve (46), which is arranged in a common supply line (27, 41) connecting the piston spaces or the ring spaces of the hydraulic cylinders (17, 18, 19), which depending on the pivot cylinder (7) lying against the respective hydraulic cylinder (17, 18, 19), opens a supply line (29) to the second control device (30) and blocks the same to the unloaded hydraulic cylinder (17, 18, 19).

8. The reversible plough (1) according to any one of the Claims 1 to 7, characterised in that the second valve unit (28) comprises a shut-off valve (33), which in a fluid-conducting manner is assigned to the piston space (22) or the annular chamber (21) of the pivot cylinder (7), wherein the shut-off valve (33) during the pivot operation is subjected to a control pressure from at least one of the two hydraulic cylinders (17, 18, 19), and on reaching a shut-off pressure preset on the shut-off valve (33) interrupts the flow into the piston space (22) or the flow out of the annular chamber (21) of the pivot cylinder (7).

9. The reversible plough (1) according to any one of the Claims 1 to 8, characterised in that on the hydraulic cylinders end-stops (39) are arranged on the outside, on which the first lever (12) supports itself.

10. The reversible plough (1) according to any one of the Claims 1 to 9, characterised in that the pivot device (8) comprises a lever arrangement (12, 14), by means of which the pivot cylinder (7) is articulated on the plough frame (4).

11. The reversible plough (1) according to any one of the Claims 1 to 10, characterised in that the pivot cylinder (7) is assigned a first shut-off block (38), which connects the supply lines (23, 24) to the piston space (22) and annular chamber (21) of the pivot cylinder (7) with supply lines (29, 35) of the second control device (30).

12. The reversible plough (1) according to any one of the Claims 2 to 11, characterised in that the double-acting hydraulic cylinders (19) are assigned a second shut-off block (42), which connects the hydraulic cylinders (19) with the second control device (30).

13. The reversible plough (1) according to any one of the preceding claims, characterised in that a pivot swing-in device for in-swinging and out-swinging acts on the plough frame (4), which is controllable depending on a pressure caused by the pivot cylinder (7) lying against one of the hydraulic cylinders (17, 18, 19), in order to swing-in the plough frame (4) before the pivot operation by the pivot cylinder (7) has been performed and swing-out the plough frame (4) on the other hydraulic cylinder (17, 18, 19) after the pivot operation has been performed with the pivot cylinder (7) lying against the other hydraulic cylinder (17, 18, 19).

14. A method (1) for operating a reversible plough (1) according to Claim 1, 2, 3 or 4.

15. The method (1) according to Claim 14, characterised in that for adjusting an inclination angle a second valve unit (28) and a second control device (30) are used which are equipped, depending on the pivot cylinder (7) lying against the respective hydraulic cylinder (17, 18, 19) to alternately pressurise the annular chamber (21) or the piston chamber (22) of the pivot cylinder (7) and depending on an increase of the inclination angle to be adjusted, simultaneously pressurise the hydraulic cylinder (17, 18, 19).

16. The method (1) according to Claim 14 or 15, characterised in that a frame swing-in device for swinging-in and swinging-out acts on the plough frame (4), which is controlled depending on a pressure caused by the pivot cylinder (7) lying against one of the hydraulic cylinders (17, 18, 19), in order to swing-in the plough frame (4) before the pivot operation by the pivot cylinder (7) has been performed and swing-out the same after the pivot operation with the pivot cylinder (7) lying against the other hydraulic cylinder (17, 18, 19) has been performed.