Device for automatic adjustment of the working width of a first plough body in accordance with subsequent plough bodies' variable working width

Abstract

A device for automatically adjusting the working width of the first plough body of a plough in accordance with the variable working width of subsequent plough bodies. A first hydraulic cylinder displaces a rear frame section laterally. A second hydraulic cylinder pivots the rear frame section to adjust a transverse spacing of the plough bodies. The first hydraulic cylinder includes a multi-stage cylinder. A first cylinder stage forms a main lateral control, and a second cylinder stage forms an automatic working-width control for the first plough body. The second cylinder stage is in hydraulic-fluid communication with the second hydraulic cylinder in a master-slave configuration. The second cylinder stage is master or the slave depending on a moving direction of the cylinder stage and the second hydraulic cylinder being slave or the master. Piston diameters are matched to provide a correction of a lateral displacement of the front frame section.

Claims

1. A device for automatically adjusting the working width of the first plough body of a plough in accordance with the variable working width of subsequent plough bodies, comprising: a first hydraulic cylinder is configured to displace a rear frame section laterally relative to a front frame section, and a second hydraulic cylinder is configured to pivot the rear frame section around a first vertical pivoting axis in order to adjust a transverse spacing of the first and subsequent plough bodies by the first and subsequent plough bodies pivoting around second vertical pivoting axes, wherein the first hydraulic cylinder comprises a multi-stage cylinder in which a first cylinder stage forms a main lateral control, and a second cylinder stage forms an automatic working-width control for the first plough body, the second cylinder stage is in hydraulic-fluid communication with the second hydraulic cylinder in a master-slave configuration, the second cylinder stage being a master or a slave depending on a moving direction of the second cylinder stage and the second hydraulic cylinder correspondingly being the slave or the master, and piston diameters of the second cylinder stage and the second hydraulic cylinder are matched to each other so that an adjustment of the transverse spacing for the first and subsequent plough bodies by the second hydraulic cylinder provides a correction of the lateral displacement of the front frame section.

2. The device in accordance with claim 1, wherein a piston of the second cylinder stage of the first hydraulic cylinder includes a first by-pass valve which, from a position near a bottom abutment of the piston onwards, opens for oil to be drained from a piston side to a piston-rod side.

3. The device in accordance with claim 1, wherein a piston of the second hydraulic cylinder includes a second by-pass valve which, from a position near a bottom abutment of the piston onwards, opens for oil to be drained from a piston side to a piston-rod side.

4. The device in accordance with claim 1, wherein the second hydraulic cylinder includes a separate memory piston forming a hydraulically displaceable bottom abutment.

5. The device in accordance with claim 1, wherein the plough is a reversible plough, and the piston-rod sides of the second cylinder stage and of the second hydraulic cylinder are interconnected by a turnover sequence valve for synchronizing the reversing of the plough with the adjustment of the working width of the plough to a minimum.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In what follows, an example of a preferred embodiment is described, which is visualized in the accompanying drawings in which:

(2) FIG. 1 shows a plough, more particularly a reversible plough, with a variable ploughing width, connected to a tractor and provided with a device for automatically adjusting the working width of the first plough body; and

(3) FIG. 2 shows a hydraulics diagram, on a larger scale, showing the hydraulic cylinder arrangement according to the invention in greater detail.

DETAILED DESCRIPTION

(4) Reference is first made to FIG. 1, in which a plough, shown here as a 3-furrow reversible plough is indicated by the reference numeral 1. The plough 1 includes a plough frame 11 and a tower 12, the plough frame 11 and the tower 12 being rotatably connected around a horizontal axis by means of a so-called headstock 123. The reversing of the reversible plough 1 is carried out by means of a turnover cylinder 122, which is connected between a front frame section 116 and the tower 12.

(5) Several plough bodies 111, 112, 113 are attached to a rear frame section 117. The rear frame section 117 is laterally displaceable relative to the front frame section 116 and the tower 12 in order to adjust the working width of a first plough body 111 to the track width and tyre width of a connected tractor, so that the distance between the inside of a rear wheel 21 of the tractor 2 and a landside 1111 of the first plough body 111 is in accordance with the working width of the other plough bodies 112, 113. The lateral displacement is provided by means of a first hydraulic cylinder 13 that, together with a lateral-displacement section 118, shown here as two parallel rods 1181, 1182, forms a connection between the front and rear frame sections 116, 117.

(6) By means of a second hydraulic cylinder 14, the rear frame section 117 is pivotal around a first vertical pivoting axis 119 arranged in the connection between the front and rear frame sections 116, 117. The beam 1112 of each plough body 111, 112, 113 is attached to the rear frame section 117, pivotal around a second vertical pivoting axis 115 and is connected to a parallel rod 114 which is anchored to the front frame section 116 via the lateral-displacement section 118. When the rear frame section 117 is pivoted, the plough bodies 111, 112, 113 pivot around their vertical pivoting axes 115, and the spacing of the plough bodies 111, 112, 113 changes, with the result that the working width of the plough 1 is being changed.

(7) Reference is now made to FIG. 2 in particular. The first hydraulic cylinder 13 includes two cylinder stages, a first cylinder stage 131, which is used for the main adjustment of the lateral position of the rear frame section 117 relative to the front frame section 116 and is connected to a first hydraulic circuit 161, accommodating a second cylinder stage 132, which is connected via a second hydraulic circuit 162 to the second hydraulic cylinder 14, piston side 1331 to piston-rod side 1422, piston-rod side 1332 to piston side 1421 via a control valve 15 which, for a reversible plough, is typically a turnover sequence valve, the second cylinder stage 131 and the second hydraulic cylinder 14 cooperating in a master-slave arrangement.

(8) The piston diameter D.sub.1a of the second cylinder stage 132 and the piston diameter D.sub.2 of the second hydraulic cylinder 14 have been matched to each other in such a way that when the working width of the plough 1 is adjusted by the second hydraulic circuit 162, the rear frame section 117 is correspondingly adjusted sideways, account having been taken, in the dimensioning of the cylinders 13, 14, of the geometry of the lateral-displacement section 118, the distance between the pivoting axis 115 of the first plough body 111 and the pivoting axis of the rear frame section 117 and so on.

(9) The second hydraulic cylinder 14 is shown here with a separate piston 144, also called a memory piston, arranged in the volume between the bottom of the hydraulic cylinder 14 and an ordinary piston 142 arranged on a piston rod 141. A cylinder volume between the bottom of the cylinder and the separate piston 144 is in fluid communication with the control valve 15 via a third hydraulic circuit 163. The memory piston 144 forms a displaceable bottom abutment in said hydraulic cylinder 14, in order thereby to set a parameter, which is important for a ploughing operation, typically an operational largest ploughing width.

(10) Both the second cylinder stage 132 in the first hydraulic cylinder 13 and the second hydraulic cylinder 14 are provided with a by-pass valve 134, 143, also termed a resetting valve, arranged in a piston 133, 142, respectively, in such a way that when said piston 133, 142 is near its bottom abutment, the by-pass valve 134, 143, respectively, opens for oil to flow through between a piston side 1331, 1421, respectively, and a piston side 1331, 1422, respectively, to ensure that both pistons 133, 142 will reach their starting positions unaffected by a possible oil leakage past the piston 133, 142 to the piston side 1331, 1421 of the piston.