Reversible plow

Abstract

A reversible plow, which has a main spindle box with a frame hinged on the main spindle box, and the frame carries at least one pair of opposite plowing members; the reversible plow has a reversing cylinder between the frame and the main spindle box, so that the frame can be rotated relative to the main spindle box from a positioning step at one side of the plow through a dead point position of the reversing cylinder to a repositioning step on the opposite side; and the reversible plow has a supporting wheel, which is mounted on the frame of the plow to adjust the working depth of the plow, the wheel can be flipped together with the frame to adjust the working depth of the plow in two rotational positions at opposite sides of the frame of the plow, and the wheel can be blocked in the operating position by a hydraulic blocking cylinder.

Description

Technical Field

[0001] The present invention relates to a reversible plow, which has a main spindle box with a frame hinged on the main spindle box, and the frame carries at least one pair of opposite tillage members; the reversible plow has a reversal cylinder between the frame and the main spindle box so that the frame can be rotated relative to the main spindle box from a positioning step at one side of the plow through a dead point position of the reversal cylinder to a repositioning step on the opposite side; and the reversible plow has a support wheel, which is mounted on the frame of the plow so as to adjust the working depth of the reversible plow, the wheel being orientable for guiding the depth of the reversible plow in two rotational positions on opposite sides of the frame of the plow, and the wheel can be actuated by a hydraulic cylinder. Background Art

[0002] A reversible plow typically consists of a frame rotatably mounted on a headstock with a three-point attachment to a farm tractor. A reversing cylinder is typically located between the frame and the headstock, which allows the frame to rotate about an articulation axis. This allows one row of tilling elements to be moved into an operating position in the forward direction, and the other row of tilling elements to be moved into an operating position in the return direction, while always plowing the same side of the cultivated land. This operation is known in the art as even plowing.

[0003] There is usually an adjustment device for the tillage depth associated with the frame, which has a wheel that rotates with the rotation of the frame and a return element that keeps the wheel in the desired operating position both in the forward direction and in the return direction. Usually, this return element is constituted by a spring or a hydraulic cylinder.

[0004] The plough is preferably provided with an alignment cylinder which, in an initial step of rotation of the frame about the articulation axis, reduces the tillage range by moving the frame towards the axis of rotation and thus brings the frame into an initial adjustment to facilitate rotation of the frame and prevent jamming of the tillage members from occurring.

[0005] A reversible plough comprising these features is known from FR 2 892 596.

[0006] In this document, the wheel alignment cylinders, reversal cylinders, and adjustment cylinders are connected to one another so that in the initial step of the frame rotation (reversal), the wheels are raised to a neutral position and are then repositioned to the opposite side by the reversal cylinders after the frame has rotated through 180°. However, the architecture of this system is quite complex and requires dual control of the hydraulic cylinders provided for adjusting the wheel depth in order to raise the wheels before reversal and then reposition the wheels to the opposite working side after reversal occurs.

[0007] WO2010 / 108468 describes a reversible plough in which a wheel for depth adjustment tilts between two predetermined positions as the frame rotates under the control of a double-acting hydraulic damping cylinder and has a pressure accumulator that regulates the exchange of oil between the two chambers of the damping cylinder.

[0008] The system also involves a relatively complex structure that may malfunction in extremely harsh environments, such as those in which agricultural machinery operates.

[0009] EP2617277 also describes another reversible plough in which the depth adjustment wheel tilts between two predetermined positions as the frame rotates. In this case, the adjustment wheel is controlled by two hydraulic cylinders arranged in sequence so that the second hydraulic cylinder is hinged to the end of the first hydraulic cylinder.

[0010] However, it became clear that this solution was particularly fragile and prone to failure. Indeed, it must be noted that each of the two cylinders must at least partially bear the weight of the plow, and is therefore subject to significant stress, including the fact that their rods can be easily loaded transversely relative to their axes. Furthermore, if the pressure in one of the two cylinders is insufficient, the other will not be able to secure the wheel in place, and the wheel—forced upwards—will rise.

[0011] Furthermore, the solution described in EP 2 617 277 is not optimal for transporting the plough. In fact, considering that the plough is transported with the frame arranged in an intermediate rotational position between the two working positions, it is not possible to position the wheels in a position suitable for transporting the plough without having to disconnect the depth adjustment cylinder.

[0012] In all the above cases, the control of the positioning of the regulating wheel on one side or the other of the frame requires the use of a double-acting hydraulic cylinder.

[0013] Therefore, it is considered necessary to provide a reversible plough of the above type which is simple in construction and preferably so as to allow position control of the depth adjustment wheel by a single-acting hydraulic cylinder in both working conditions of the plough. Summary of the Invention

[0014] The technical problem addressed by the present invention is to provide a reversible plough which is structurally and functionally configured to at least partially overcome one or more of the disadvantages stated with reference to the cited prior art.

[0015] The present invention solves this problem by means of a reversible plow constructed according to an embodiment.

[0016] According to the invention, this problem is solved by a reversible plow comprising: a spindle box to which a frame is hingedly connected, the frame in turn carrying preferably at least one pair of opposite tilling members; and a reversing cylinder between the frame and the spindle box so that the frame can be rotated relative to the spindle box between two tilling operating positions from a positioning step at one side of the plow, preferably via a dead point position of the reversing cylinder to a repositioning step on the opposite side.

[0017] Support wheels are also provided, mounted on the plow frame, to adjust the plow's working depth. It should be noted that the wheels can be pivoted together with the frame, allowing the plow's working depth to be adjusted in two rotational positions, on opposite sides of the plow frame. Furthermore, the wheels can be blocked in the operating position by a hydraulic blocking cylinder.

[0018] It should be understood that, according to an embodiment of the present invention, the hydraulic blocking cylinder includes a pressurized chamber that is selectively hydraulically connected to the reversing cylinder and / or the alignment cylinder via a control valve. The control valve is preferably configured to connect the pressurized chamber for exhaust during the step of rotating the plow by the reversing cylinder, and to supply pressure to the chamber while the reversing cylinder and / or the alignment cylinder are performing or have completed the repositioning step. In this case, the hydraulic blocking cylinder is advantageously configured to allow wheel orientation during rotation of the plow and to block wheel orientation when the plow assumes the plowing operating position.

[0019] In one aspect, the control valve is controlled by a pressure difference between a first hydraulic circuit hydraulically connected to the reversing cylinder and a second hydraulic circuit hydraulically connected to the aligning cylinder.

[0020] Advantageously, the hydraulic circuit, which can be freely selected between the first hydraulic circuit and the second hydraulic circuit, is also hydraulically connected to the pressurization chamber of the hydraulic blocking cylinder. According to another advantageous aspect, the control valve comprises a single-acting interception valve configured to intercept the flow of fluid discharged in one direction via the freely selectable hydraulic circuit. It will be appreciated that in this case, the interception valve is preferably controlled by the pressure difference between the first hydraulic circuit and the second hydraulic circuit to cause the interception valve to open.

[0021] The invention also allows the use of a single-acting hydraulic cylinder provided with a single pressurized chamber (or a single pressurized chamber to control a double-acting cylinder) in order to block the tilting of the wheel support in two operating positions, one on one side of the frame and the other, after rotation of the frame.

[0022] In some preferred embodiments, the hydraulic blocking cylinder is connected to the frame of the plow on one side and to the wheel support on the other side. More specifically, the hydraulic blocking cylinder has a longitudinal end connected to the frame of the plow and an opposite longitudinal end connected to the wheel support. It will be appreciated that, preferably, the wheel support is mounted on the frame in a manner that can pivot between two rotational positions on opposite sides of the frame. This structure allows the wheel support to be blocked not only in the two rotational positions on opposite sides of the frame, but also in an intermediate rotational position between the two positions on opposite sides of the frame when necessary, for example, a rotational position rotated approximately 90° from the two positions on opposite sides of the frame, so that the wheel is positioned in a position suitable for transporting the plow. For this purpose, in some embodiments, the wheel support is mounted on the frame in a manner that can pivot between two positions, around an axis parallel to the direction of advance of the plow during the tillage step or the transport step.

[0023] In the plowing operating position, when pressure is supplied to the pressurized chamber of the hydraulic blocking cylinder, the wheel supports are preferably pulled back against an abutment, such as an abutment of the frame, by corresponding abutments of the wheel supports in both blocking operating positions on opposite sides of the frame. This advantageously ensures that the weight of the plow in the plowing operating position is unloaded on the corresponding abutments of the wheel supports, rather than on the hydraulic blocking cylinder. Furthermore, the weight of the plow advantageously ensures that, in the plowing operating position, the wheel supports remain in contact with the frame supports, even if the pressure in the hydraulic blocking cylinder is unexpectedly insufficient.

[0024] Advantageously, the wheel supports can be adjusted by means of hydraulic adjusting cylinders in order to adjust the working depth of the plough. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The characteristics and advantages of the present invention will be better understood from the detailed description of a preferred non-limiting embodiment of a reversible plough according to the invention, illustrated by way of non-limiting example with reference to the accompanying drawings, in which:

[0026] - Figure 1 Shows a support for a depth wheel provided with a hydraulic blocking cylinder according to the invention;

[0027] - Figure 2 is a rear view of the main shaft box of the plow according to the present invention;

[0028] - Figure 3 Shows the frame of the plow and Figure 2 The articulation of the spindle box;

[0029] - Figure 4 and Figure 5 They are Figure 1 Schematic diagram of the valve group in the unblocking and blocking steps of the wheel;

[0030] - Figure 6 yes Figure 4 and Figure 5 Detailed picture of

[0031] - Figures 7 to 11 A series of steps for turning a plow in accordance with the present invention are shown;

[0032] - Figure 12 yes Figure 4 and Figure 5 Detailed schematic diagram. DETAILED DESCRIPTION

[0033] With reference to the cited figures, the reversible plough 1 comprises a headstock 2 provided with a three-point attachment to an agricultural tractor, not shown, by which the plough can be pulled for tillage work, as will be better explained below.

[0034] A frame 3 is hingedly connected to the main spindle housing 2, which in turn carries at least one pair (and preferably multiple pairs) of opposing tilling members 4. A reversing cylinder 5 is interposed between the frame 3 and the main spindle housing 2 to allow the frame to rotate relative to the main spindle housing between two tilling operating positions. Advantageously, the two tilling operating positions are approximately 180° opposite each other. According to another advantageous aspect, in both tilling operating positions, the tilling members 4 located on the same side of the frame 3 are respectively engaged in the soil to be cultivated.

[0035] On the one hand, the rotation of the frame 3 about its articulation axis is approximately 180°. It will be appreciated that the rotation of the frame 3 and therefore of the tillage member 4 is carried from a positioning step on one side of the plough, in which the tillage member 4 advantageously tills a portion of the tilled land on one side during the forward stroke, to a repositioning step on the opposite side, in which the tillage member 4 advantageously tills a portion of the tilled land on the same side in the opposite direction during the return stroke, thus performing level tillage in this way.

[0036] The rotation of the frame 3 passes through the dead center position of the reversing cylinder 5. Advantageously, the reversing cylinder 5 comprises a rod 5a, in which position the rod 5a is maximally retracted, and a first chamber 5c and a second chamber 5d, the first chamber and the second chamber being delimited by the piston 5b to a maximum volume condition and a minimum volume condition in the cylinder 5, respectively.

[0037] In a preferred embodiment, an alignment cylinder 6 is further disposed between the frame 3 and the headstock 2. This alignment cylinder is configured to reduce the tilt angle of the frame 3 relative to its axis of rotation, moving the frame 3 toward the axis of rotation during the pre-rotation steps. This facilitates the frame's rotation and overcomes dead points, further preventing the plow's working members 4 or other components from contacting the ground during the reverse rotation. Similarly, the alignment cylinder 6 is configured to return the frame 3 to its initial adjustment position after the rotation is complete. Advantageously, the alignment cylinder 6 is configured to adjust the tilt angle of the frame 3 relative to its axis of rotation without changing the working width. In one aspect, the alignment cylinder 6 also comprises a first chamber 6c and a second chamber 6d, each bounded by a piston 6b having a rod 6a.

[0038] It may be noted that, in this context, the term "alignment" is preferably intended to be understood as meaning the action of reducing the working width of the plough 1 by moving the frame 3 towards its axis of rotation.

[0039] On the one hand, the reversing cylinder 5 and the aligning cylinder 6 are actuated by pressurized hydraulic fluid which is supplied by a tractor (not shown) pulling the plough 1 through a supply pipe 8 and a discharge pipe 9 via a valve group, generally designated 10. Figure 4 and Figure 5 A possible schematic diagram of the valve group 10 is shown in FIG.

[0040] This figure shows a so-called rotary valve 10a with a memory, which is provided so that by actuating the rotation control of the plough 1 on the agricultural tractor, the supply pipe 8 is connected to the source of pressurized fluid and to the discharge pipe 9 for discharge, the alignment of the frame 3 is started via the alignment cylinder 6, the rotation of the frame 3 is started by the reversing cylinder 5, and when the rotation is completed, the frame 3 is realigned according to the desired alignment by the alignment cylinder 6.

[0041] like Figure 1As shown in the example of FIG, the support wheel 11 is mounted on the frame 3 via a support 12, which can be adjusted by a hydraulic adjustment cylinder 13 to adjust the working depth of the reversible plow. It will be understood that in some embodiments, the hydraulic adjustment cylinder 13 can be replaced or supplemented by a mechanical tie rod (not shown) to adjust the working depth of the plow. In a preferred embodiment, the support 12 of the wheel 11 is mounted in a tiltable manner on a bracket 14, which is hinged to the bracket 14 by a pin 15 having an axis X.

[0042] It is preferred to fix the bracket 14 to the frame 3, for example to fix the bracket 14 to the frame 3 in a rigid manner. It is also preferred that the bracket 14 protrudes from the frame 3.

[0043] Preferably, the axis X is parallel to the direction of advancement of the plough during the tillage step and, in turn, preferably, is substantially parallel to the plane defined by the ground to be tilled in the tillage operating position.

[0044] The wheel 11, together with the support 12, can pivot about 180° about the axis X of the pin 15 between two opposite positions, which are in tandem and coincident with the turning over of the frame 3 of the plough 1 by the turning cylinder 5. Due to the turning over of the frame 3, the wheel 11 will advantageously be arranged at one side and at the opposite side of the frame 3, respectively, still oriented towards the ground.

[0045] In both operating positions, the blocking of the tilting of the support 12 is achieved by means of the hydraulic blocking cylinder 17 .

[0046] On the one hand, a hydraulic blocking cylinder 17 is interposed between a flange 18 of the bracket 14 and an additional pin 19 positioned on the support 12. The hydraulic blocking cylinder 17 has dimensions that allow the wheel 11 to tilt by approximately 180° about the axis of the pin 15. Preferably, this is a single-acting hydraulic cylinder, the rod 21 and the piston 22 of which define a single pressurized chamber 20 which, when supplied with pressurized oil, exerts a return movement that brings the rod 21 into the retracted position, while, when connected for discharge, it allows free extension of the rod 21 due to the influence of the weight acting on the wheel 11, so as to allow the wheel 11 to tilt as indicated above.

[0047] It will be understood that when the pressurized chamber 20 of the blocking cylinder 17 is supplied with pressure, the support 12 is preferably pulled back in the two blocking operating positions by its corresponding abutment 25 to abut against the abutment 23 of the bracket 14. Therefore, in a preferred embodiment, the bracket 14 has two opposite abutments 23, which are configured to abut the corresponding abutments 25 of the support 12.

[0048] It must be noted that, preferably, the wheel support 12 comprises: a first support 12a, which is hinged to the bracket 14 by a pin 15 with an axis X; and a second support 12b, which is hinged to the first support 12a so as to allow the second support 12b to tilt relative to the first support 12a.

[0049] It is preferable to form the abutment pieces 25 on corresponding opposite sides of the first support piece 12a.

[0050] Advantageously, wheel 11 is associated with second support 12b so that tilting the second support 12b relative to the first support 12a allows adjustment of the working depth of the plow. It will be appreciated that a hydraulic adjustment cylinder 13 is interposed between the first and second supports 12a, 12b, to adjust the position of the second support 12b relative to the first support 12a. Conversely, a hydraulic blocking cylinder 17 is preferably interposed between a flange 18 of bracket 14 and an additional pin 19 placed on the first support 12a. In this manner, hydraulic adjustment cylinder 13 is advantageously configured to adjust the working depth of plow 1 independently of the actuation of hydraulic blocking cylinder 17.

[0051] For this purpose, it is preferred that the hydraulic adjustment cylinder 13 and the hydraulic blocking cylinder 17 are not coplanar at least in two tillage operation positions.

[0052] According to another advantageous aspect, the wheel 11 can be turned together with the frame 3 at opposite sides of the frame 3 in two rotational positions, while keeping the working depth of the plough 1 constant.

[0053] Furthermore, due to the above-mentioned structural features, the wheels 11 can be arranged in a position suitable for transporting the plough 1 .

[0054] In particular, when the frame 3 is rotated to the transport position, that is, the frame 3 is in an intermediate rotation position between the two tillage operating positions, typically rotated about 90° relative to each of the two tillage operating positions, the wheel support 12 can be rotated around the axis X between the two positions on opposite sides of the frame in a manner that is in the same direction and consistent with the rotation of the frame 3 until the intermediate rotation position of the support 12, preferably rotated through about 90° from each of the two positions on opposite sides of the frame.

[0055] After this rotation, the wheel support 21 can be blocked in a single intermediate rotational position by actuating the hydraulic blocking cylinder 17 .

[0056] During the rotation of the support 12 away from and towards the intermediate rotational position, the depth adjustment cylinder 13 can remain connected to the support 12 and can maintain its adjustment unchanged.

[0057] exist Figure 4 and Figure 5 The hydraulic connection of the blocking cylinder 17 is schematically shown in the example of FIG.

[0058] like Figure 4 and Figure 5 In the example shown in FIG. 1 , the valve group 10 includes a rotary valve 10 a. Figure 12 A schematic diagram of a rotary valve 10a is shown in the example of FIG. It will be appreciated that, in one aspect, the rotary valve 10a allows alignment operations of the frame 3 and rotation operations of the frame to be performed using a maximum pressure valve that is appropriately calibrated to perform an alignment control sequence through raising, reversing, and repositioning of the frame 3.

[0059] In one embodiment, the hydraulic connection of the hydraulic blocking cylinder 17 is coupled to the valve block 10 by means of a control valve 24, which controls the supply and exhaust of the pressurized chamber 20 of the blocking cylinder 17. It will be appreciated that, in one aspect, the pressurized chamber 20 is the only pressurized chamber of the hydraulic cylinder 17. It must be noted that the hydraulic connection of the pressurized chamber 20 to the valve block 10 is achieved at a location 30, where there is also a hydraulic connection of the rotary valve 10a, the second chamber 6d of the alignment cylinder 6, and the branch C2 of the second hydraulic circuit D2 of the control valve 24, as will be described below.

[0060] exist Figure 6 Schematic diagram of the control valve 24 and related hydraulic connections is shown in FIG. The first hydraulic circuit D1 and the second hydraulic circuit D2 of the control valve 24 can be seen.

[0061] The first hydraulic circuit D1 includes a branch V1 hydraulically connecting the rotary valve 10a and the control valve 24, and a branch C1 hydraulically connecting the control valve 24 and the first chamber 5c of the reversing cylinder 5. Advantageously, the branch V1 and the branch C1 are hydraulically connected to each other in the control valve 24.

[0062] The second hydraulic circuit D2 comprises a branch V2 hydraulically connecting the discharge pipe 9 to the control valve 24, and a branch C2 hydraulically connecting the control valve 24 to the position 30. Advantageously, the branches V2 and C2 are hydraulically connected to each other by means of an interposed single-acting holding valve in the control valve 24, which is controlled so as to open as described in detail below.

[0063] In the first hydraulic circuit D1 of the control valve 24 , fluid circulation is free in both directions, from the branch V1 to the branch C1 (direction V1 - C1 ) and from the branch C1 to the branch V1 (direction C1 - V1 ).

[0064] In the second hydraulic circuit D2 of the control valve 24, fluid circulation is free in the direction from branch V2 to branch C2 (direction V2-C2), while flow is normally blocked in the opposite direction (direction C2-V2) from branch C2 to branch V2. Control of flow in the C2-V2 direction depends on the pressure difference between the two hydraulic circuits of the control valve 24 (first hydraulic circuit D1 relative to second hydraulic circuit D2). Unblocking the control valve 24 in the C2-V2 direction is subordinate to the fact that the pressure difference in the first circuit D1 exceeds the value in the second circuit D2 by a predetermined threshold (e.g., 4 bar). For example, when the pressure in the first circuit D1 is approximately 200 bar and the pressure in the second circuit D2 is approximately 0 bar, the valve in the C2-V2 direction opens. When the pressure in the first circuit D1 reaches 0 bar and the pressure in the second circuit D2 reaches 200 bar, the passage is blocked.

[0065] To regulate the oil flow through the control valve 24 , the control valve 24 may include an actuation selectable between mechanical actuation, hydraulic actuation, pneumatic actuation, electrical actuation, electronic actuation, and / or actuation by gravity.

[0066] It must be observed that the plough 1 is configured to perform a reversal of the frame 3 by approximately 180° about the reversal axis in a first direction of rotation or in a second direction of rotation opposite to the first direction of rotation, so as to rotate the frame 3 relative to the headstock 2 between two working operating positions. Figures 7 to 11 In the sequence of FIG, purely for illustrative purposes, the reversal step of the plough is shown in a modified manner relative to the conventional reversal step. In practice, frame 3 is Figures 7 to 9 Rotate through 90° in the first direction of rotation and then, in order to Figure 10 and Figure 11 The support wheel 11 is clearly shown in FIG. Figures 9 to 11 , the frame 3 does not complete the reversal, but rotates through 90° in a second rotation direction opposite to the first rotation direction, essentially returning to the position where it was already Figure 7 When the reversing control of the plough for rotating the frame 3 by 180° about the single rotation axis is actuated so as to reverse the series of tillage members 4 to the working operating position, pressurized oil is delivered (e.g. 200 bar) to the supply pipe 8 and the discharge pipe 9 is connected for discharge, as shown. Figure 4 An example of this is shown in the hydraulic diagram.

[0067] You will realize that Figure 4 Hydraulic diagram and Figures 7 to 9 The inversion steps of the framework basically correspond to .

[0068] In this case, the rotary valve 10 a authorizes draining of the rod 6 a of the alignment cylinder 6 , thereby supplying pressurized oil (eg 200 bar) to the first chamber 6 c and draining oil from the second chamber 6 d of the alignment cylinder 6 .

[0069] It will be appreciated that, advantageously, in these conditions, the oil discharged from the second chamber 6d of the alignment cylinder cannot flow towards the control valve 24 since the pressure in the first chamber 5c of the reversal cylinder is 0 bar and the control valve 24 is therefore prevented from passing through the second circuit D2.

[0070] In practice, during the first alignment step of the frame, the oil discharged from the second chamber 6d of the alignment cylinder flows through the channel 60 to the rotary valve 10a. On the one hand, the oil discharged from the alignment cylinder 6 during this step can only flow through the channel 60, because the theoretical pressure of the flow leaving the second chamber 6d is 0 bar, just as it is in the first chamber 5c of the reversing cylinder (also 0 bar). Consequently, there is no pressure variation between the first circuit D1 and the second circuit D2, and the control valve 24 blocks the flow in the direction 2C-V2. Indeed, it must be noted that under these conditions, the reversing cylinder 5 only has the pressure required to hold the reversing cylinder 5, and therefore the frame 3, in position, in its second chamber 5d.

[0071] When rotation begins, the first chamber 5c of the reversing cylinder will have a theoretical pressure of 200 bar, and the first circuit D1 will be supplied with a theoretical pressure of 200 bar. This creates a pressure differential between the first circuit D1 and the second circuit D2. In this step, starting with the second circuit D2 at a theoretical pressure of 0 bar, the control valve 24 opens by allowing oil to flow from the pressurized chamber 20 of the blocking cylinder 17.

[0072] Under these conditions, the hydraulic blocking cylinder 17 of the wheel 11 is free to discharge the hydraulic fluid from the pressurizing chamber 20 to the control valve 24 and / or the rotary valve 10 a , thereby releasing the wheel 11 .

[0073] When the alignment step of the frame 3 is completed by the alignment cylinder 6, the rotary valve 10a authorizes the reversing cylinder 5 to start rotating the frame 3, thereby delivering oil to the first chamber 5c of the reversing cylinder 5. This operation will allow the oil to pass through the first circuit D1 of the control valve 24 in the direction V1-C1 without hindrance.

[0074] Under these conditions, the first circuit D1 of the control valve 24 is under pressure (theoretical pressure is 200 bar), while the second circuit D2 of the control valve 24 is vented in the direction C2-V2 (theoretical pressure is 0 bar). Therefore, the control valve 24 does not prevent the oil from passing through the second circuit D2 in the direction C2-V2, connecting it to vent the pressurized chamber 20 of the hydraulic blocking cylinder 17 of the wheel 11 and allowing the rod 21 to be withdrawn due to the action of gravity on the wheel 11.

[0075] When the reversing cylinder 5 reaches the dead point, the rotary valve 10a allows the reversing to continue and thus delivers the pressurized fluid to the second chamber 5d of the reversing cylinder 5 while being connected for draining the first chamber 5c (drain pipe 9), as shown in FIG. Figure 5 shown.

[0076] You will realize that Figure 5 The hydraulic diagram of the example corresponds essentially to the Figures 9 to 11 The inversion step of the frame.

[0077] In this case, the first circuit D1 of the control valve 24 is not hindered in any way in the direction C1 - V1 , and the oil can be discharged to the rotary valve 10 a or the discharge pipe 9 .

[0078] When the rotation of the frame 3 is complete and the maximum extension point of the reversing cylinder 5 has been reached, the rotary valve 10a allows the alignment cylinder 6 to bring the frame 3 of the plough 1 back into the tilling position by supplying pressurized fluid to the second chamber 6d of the alignment cylinder 6 via the channel 60.

[0079] In this case, there will be pressure in the second hydraulic circuit D2 of the control valve 24 (theoretical pressure is 200 bar), while the first hydraulic circuit D1 will be connected to exhaust (theoretical pressure is 0 bar). Therefore, the second circuit D2 will be closed and the oil from the rotary valve 10a through the channel 60 will only be able to reach the alignment cylinder 6 and / or the blocking cylinder 17, thereby positioning the wheel 11 and holding the abutment 25 against the abutment 23.

[0080] It will be appreciated that the alignment cylinder 6 is used to ensure that the frame 3 has completed its rotation and that the wheel 11 is securely in the correct blocked position; however, the same process can be performed using the reversing cylinder 5. In this case, the reversing cylinder 5 can be used solely to drain the oil through the control valve 24, while there is oil flowing to the first chamber 5c of the reversing cylinder. It must be noted that in this case, it is necessary to directly connect the second chamber 5d and the branch C2 of the control valve (and therefore also the pressurized chamber 20 of the blocking cylinder). In this way, during the reversal between the upward movement of the reversing cylinder's rod 5a and the downward movement of this rod 5a, there is an immediate repositioning of the wheel support 12 (vertical at 90° relative to the horizontal tilling member 4) with the abutment 25, which will move into contact with the abutment 23. In one aspect, a throttle valve (not shown) is provided, which is configured to slow down the repositioning of the wheel support 12.

[0081] It will be appreciated that the reversing cylinder 5 is used to control the control valve 24 for ease of operation; however, the alignment cylinder 6 could be used to perform the same function. In this case, the first chamber 6c of the alignment cylinder is connected to the first circuit D1, while the second chamber 6d and the pressurization chamber 20 are connected to the second circuit D2. In this case, when the first chamber 6c is supplied, the control valve 24 allows pressure to be discharged from the second circuit D2. Advantageously, a pressure accumulator (not shown) is provided, which is hydraulically connected to the pressurization chamber 20 and is configured to receive oil discharged from the pressurization chamber 20 to allow reversal of the blocking cylinder 17.

[0082] The invention thus solves the problem posed by the simple intervention of modifying the hydraulic mounting and using a single-acting cylinder for blocking the wheel 11 .

[0083] Advantageously, its control is fully automatic and does not require any structural complexity.

[0084] The present invention also achieves several other advantages, including:

[0085] - prevent incorrect positioning of the wheel supports,

[0086] - always ensuring the correct alignment of the wheels relative to the vertical direction of the tillage member, including situations where they are not in the correct vertical arrangement (such as, for example, in working conditions on a hill),

[0087] - Ensures wheel positioning by preventing accidental lifting of the wheel, even if the pressure in the hydraulic blocking cylinder is unexpectedly insufficient,

[0088] - allows the wheel to be positioned in a position suitable for transporting the plough without having to disconnect the depth adjustment cylinder,

[0089] -Prevents premature wear of the wheel supports due to incorrect alignment.

Claims

1. A reversible plow (1), the reversible plow having a spindle box (2) on which a frame (3) is hingedly connected, the frame in turn carrying at least one pair of opposite tillage members (4); the reversible plow having a reversing cylinder (5) between the frame (3) and the spindle box (2) so that the frame (3) can be rotated relative to the spindle box (2) from a positioning step at one side of the reversible plow (1) through a dead point position of the reversing cylinder (5) to a repositioning step at the opposite side between two tillage operation positions; and the reversible plow having a supporting wheel (11) mounted on the frame (3) of the reversible plow (1) so as to adjust the working depth of the reversible plow, the supporting wheel (11) being capable of being flipped together with the frame (3) so as to adjust the reversible plow (1) in two rotational positions at opposite sides of the frame (3) of the reversible plow (1). The working depth is adjusted, and the support wheel can be blocked in the operating position by a hydraulic blocking cylinder (17), the reversible plow is characterized in that the hydraulic blocking cylinder (17) has a pressurized chamber (20), which is selectively hydraulically connected to the reversing cylinder (5) and / or the alignment cylinder (6) by a control valve (24), the control valve (24) is configured to connect the pressurized chamber (20) for discharge during the step of rotating the reversible plow (1) by the reversing cylinder (5), and the control valve is configured to supply pressure to the pressurized chamber (20) when the reversing cylinder (5) and / or the alignment cylinder (6) are undergoing a repositioning step or have completed a repositioning step, the hydraulic blocking cylinder (17) is configured to allow the orientation of the support wheel (11) during the rotation of the reversible plow (1) and to block the orientation of the support wheel (11) when the reversible plow (1) is in the plowing operating position, wherein The hydraulic blocking cylinder (17) is connected on one side to the frame (3) of the reversible plough (1) and on the other side to a support (12) of the support wheel (11), the support (12) being mounted on the frame (3) in such a way that it can pivot between two rotational positions on opposite sides of the frame (3).

2. The reversible plough (1) according to claim 1, wherein: When the pressurized chamber (20) is supplied with pressure, the support (12) is pulled back in two blocking operation positions at opposite sides of the frame (3) by corresponding abutments of the support (12) to abut against abutments of the bracket (14).

3. The reversible plough (1) according to claim 2, wherein: The abutment of the bracket (14) is fixedly engaged to the frame (3).

4. The reversible plough (1) according to claim 2 or 3, wherein: The support member (12) is mounted on the bracket (14) in a tiltable manner.

5. The reversible plough (1) according to claim 4, wherein: The bracket (14) is fixed to the frame (3).

6. The reversible plough (1) according to claim 4, wherein: The support member (12) is hinged to the bracket (14) via a pin (15).

7. The reversible plough (1) according to claim 6, wherein: The pin (15) has an axis (X) parallel to the direction of advancement of the reversible plough (1) during a tillage or transport step.

8. The reversible plough (1) according to claim 7, wherein: The hydraulic blocking cylinder (17) has dimensions that allow the support wheel (11) to be tilted by 180° about the axis (X) of the pin (15).

9. The reversible plough (1) according to claim 6, wherein: The support member (12) includes: a first support member (12a) hinged to the bracket (14) through the pin (15); and a second support member (12b) hinged to the first support member (12a) so as to allow the second support member (12b) to tilt relative to the first support member (12a).

10. The reversible plough (1) according to claim 9, wherein: The support wheel (11) is associated with the second support (12b) such that tilting of the second support (12b) relative to the first support (12a) allows the working depth of the reversible plough (1) to be adjusted.

11. The reversible plough (1) according to claim 9, wherein: A hydraulic adjustment cylinder (13) or a mechanical pull rod is inserted between the first support member (12a) and the second support member (12b) so as to adjust the position of the second support member (12b) relative to the first support member (12a).

12. The reversible plough (1) according to claim 11, wherein: The hydraulic adjustment cylinder (13) or the mechanical tie rod is configured to adjust the working depth of the reversible plough (1) independently of the actuation of the hydraulic blocking cylinder (17).

13. The reversible plough (1) according to claim 4, wherein: The hydraulic blocking cylinder (17) is interposed between a flange (18) of the bracket (14) and an additional pin (19) positioned on the support (12).

14. A reversible plough (1) according to any one of claims 1 to 3, wherein: The support wheels (11) are allowed to be positioned in a position suitable for transporting the reversible plough (1).

15. A reversible plough (1) according to any one of the preceding claims 1 to 3, wherein: The control valve (24) is controlled by a pressure difference between a first hydraulic circuit (D1) hydraulically connected to the reversing cylinder (5) and a second hydraulic circuit (D2) hydraulically connected to the aligning cylinder (6).

16. The reversible plough (1) according to claim 15, wherein: A hydraulic circuit freely selectable between the first hydraulic circuit (D1) or the second hydraulic circuit (D2) is also hydraulically connected to the pressurizing chamber (20) of the hydraulic blocking cylinder (17).

17. The reversible plough (1) according to claim 16, wherein: The control valve (24) comprises a single-acting intercepting valve configured to intercept the flow of fluid discharged through the freely selectable hydraulic circuit in one direction, the intercepting valve being controlled to open by the pressure difference.

18. A reversible plough (1) according to any one of claims 1 to 3, wherein: The hydraulic blocking cylinder (17) is a single-acting hydraulic cylinder provided with a single pressurizing chamber (20).

19. The reversible plough (1) according to claim 11, wherein: The support (12) can be adjusted by means of a hydraulic adjustment cylinder (13) and / or a mechanical drawbar, which are configured to adjust the working depth of the reversible plough (1).

20. The reversible plough (1) according to claim 19, wherein: The hydraulic adjustment cylinder (13) or the mechanical tie rod is configured to adjust the working depth of the reversible plough (1) independently of the actuation of the hydraulic blocking cylinder (17).

21. A reversible plough (1) according to any one of claims 1 to 3, wherein: The support (12) is mounted on the frame (3) in such a way that it can pivot between two rotational positions at opposite sides of the frame (3) about an axis (X) parallel to the direction of advance of the reversible plough (1) during a tillage step.

22. A reversible plough (1) according to any one of claims 1 to 3, wherein: The support wheel (11) can be tilted together with the frame (3) into two rotational positions on opposite sides of the frame (3), while keeping the working depth of the tiltable plough (1) constant.

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