Technical field

The present invention relates to an agricultural implement, the working depth of which is adjustable, and to a method for adjusting the working depth of an agricultural implement. Background

It is known that agricultural implements for soil cultivation can comprise a plurality of tilling tools, such as harrow tines, discs, cultivator tines, levelling implements, plough blades, seed furrow openers, sowing shares, seed furrow closers, etc.

It is desirable to be able to transport agricultural implements on public roads, which, inter alia, means that the width of the agricultural implement must be able to made less than a certain measure, often 3 metres, but also that the tools must be able to be drawn up sufficiently far from the ground to ensure that they do not engage with the road surface during such transport. Some agricultural implements have one or more transport wheels, which can be adjustable between a transport position, in which the transport wheels bear against the ground and the tools are elevated from the ground, and a working position, in which the the transport wheels are elevated from the ground and the tools engage with the soil. The height adjustment of the transport wheels relative to the frame of the agricultural implement is usually realized with the aid of one or more hydraulic cylinders.

It is often desirable to be able to adjust the working depth of the tilling tools. There are a plurality of agricultural implements whose working depth can be adjusted with the aid of hydraulic cylinders which act between the frame of the agricultural implement and a support, such as, for

RECORD COPY-TRANSLATION

R example, one or more wheels or surface compactor rollers .

There is a need to provide agricultural implements whose functioning and handling are simplified and whose production cost is as low as possible, but which are sufficiently robust so as to withstand the stresses to which they are exposed in both work and transport.

Summary

One object is therefore to provide a simplified agricultural implement.

The invention is defined by the appended independent claims. Embodiments of the invention will be apparent from the dependent claims, from the appended description and from the drawings.

According to a first aspect, an agricultural implement for soil cultivation is provided, comprising a main frame, a side section frame, which is rotatable relative to the main frame, at least one transport wheel, at least one tilling tool, at least one ground- contacting depth holder, associated with the side section frame, for controlling a working depth for the said tilling tool, and a first actuator, for controlling a height position for the said transport wheel relative to the main frame, or for controlling a height position for the said depth holder relative to the main frame. The depth holder is connected to the transport wheel, so that both the height position of the depth holder and the height position of the transport wheel are simultaneously controllable by the said first actuator.

By "main frame" is meant the frame which essentially defines the shape and extent of the agricultural implement. It will be appreciated that the main frame can comprise a number of parts which can be moved relative to one another, such as side sections or sections which are separated in the longitudinal direction . By "actuator" is meant a motion-generating device, such as a hydraulic or pneumatic cylinder. It will be appreciated that an actuator can comprise, for example, one or more parallelly or serially connected cylinders of this kind.

The agricultural implement can be configured just for soil cultivation, such as a cultivator, harrow or plough, for soil cultivation and feed-out of material (seed, fertilizer, pesticide) , or just for feed-out of material.

The connection between transport wheel and depth holder can be direct, for example in the form of a coupling between the respective wheel axles, and/or indirect, for example in the form of a coupling between a frame which supports the transport wheel or the depth holder .

An agricultural implement according to the above is simplified, since it only requires one actuator for controlling the height positions of both the transport wheels and the depth holder. There is thus also a potential for reducing the production cost.

According to one embodiment, the transport wheel can be suspended from a transport wheel frame, which can be movable relative to the main frame.

In addition, the depth holder can be suspended from a depth holder frame, which can be movable relative to the therewith associated side section frame .

The transport wheel frame can be connected to the depth holder frame, preferably by a mechanical coupling .

By "mechanical coupling" is meant a motion- transmitting part, such as a beam or a rod. It is also conceivable to provide a mechanical coupling which utilizes chains, gearwheels, cables or the like.

A mechanical coupling of this kind can be provided at relatively low cost. The mechanical coupling can engage with at least one of the transport wheel frame and the depth holder frame via a joint which allows rotation about at least two axes.

The transport wheel frame can be connected to the depth holder frame by a hydraulic or pneumatic connection .

A hydraulic or pneumatic connection allows greater freedom in the positioning of a second actuator, and thus an agricultural implement with greater width can be provided, compared with that which is allowed by a mechanical coupling between the depth holder and the transport wheel frame.

At least one second actuator can be arranged to act between the side section frame and the depth holder frame .

The second actuator can comprise one or more parallelly connected and/or serially connected cylinders .

The second actuator can be arranged as master actuator or slave actuator to the first actuator.

Activation of the first actuator is thus sufficient to effect activation also of the second actuator .

The transport wheel frame can have a first pivot point relative to the main frame and the depth holder frame can have a second pivot point relative to the main frame, and the transport holder frame can be connected to the depth holder frame such that, viewed in a vertical plane along the longitudinal direction of the agricultural machine, a rotation of the transport wheel frame in a first rotational direction about the first pivot point gives rise to a rotation of the depth holder frame in a second rotational direction about the second pivot point.

According to one embodiment, the first and second rotational directions can be substantially the same. According to another embodiment, the first and second rotational directions can be substantially opposite .

According to a second aspect, a method is provided for adjusting the height of an agricultural implement for soil cultivation, which agricultural implement comprises a main frame, a side section frame, which is rotatable relative to the main frame, at least one transport wheel, at least one tilling tool, and at least one ground-contacting depth holder, associated with the side section frame, for controlling a working depth for the said tilling tool. By activation of a single first actuator, both the height position of the transport wheel relative to the main frame and the height position of the depth holder relative to the main frame are controlled.

In the method, the first actuator can be activated for adjustment of one of the height position of the transport wheel relative to the main frame and the height position of the depth holder relative to the main frame, and wherein the other of the height position of the transport wheel relative to the main frame and the height position of the depth holder relative to the main frame is adjusted via a mechanical coupling between the transport wheel and the depth holder .

Alternatively, the said first actuator can be activated for adjustment of one of the height position of the transport wheel relative to the main frame and the height position of the depth holder relative to the main frame, and wherein the other of the height position of the transport wheel relative to the main frame and the height position of the depth holder relative to the main frame is adjusted with the aid of a second actuator which is coupled as master or slave to the first actuator.

According to a further aspect, an agricultural implement for soil cultivation is provided, comprising a main frame, at least one transport wheel, at least one tilling tool, at least one ground-contacting depth holder for controlling a working depth for the said tilling tool, and an actuator, for controlling a height position for the said transport wheel relative to the main frame, or for controlling a height position for the said depth holder relative to the main frame. The depth holder is connected to the transport wheel, so that both the height position of the depth holder and the height position of the transport wheel are simultaneously controllable by the said actuator.

Controlling of depth holder and transport wheel according to that which is described in this document is thus also applicable to agricultural implements which do not have any side section.

Brief description of the drawings

Fig. 1 shows an agricultural implement viewed from the side, in so-called "field transport position".

Fig. 2 shows the agricultural implement viewed from the side, in a working position.

Fig. 3 shows the agricultural implement viewed from above, in a road transport position.

Figs. 4 and 5 show schematic diagrams of an agricultural tool according to two different embodiments .

Figs. 6a-6b show views from above of an agricultural implement in working position and road transport position respectively, according to an alternative embodiment.

Figs. 7a-7b show side views of the agricultural implement according to Fig. 6.

Description of embodiments

With reference to Fig. 1, an agricultural implement 1 comprises a main frame 10, a plurality of tilling tools 12, which are suspended directly or indirectly relative to the frame and are here constituted by harrow tines.

The agricultural implement 1 can further comprise one or more depth holders 13, which can have the form of a surface compactor that can comprise surface compactor rollers made of metal or rubber. Alternatively, or complementary thereto, the depth holder 13 can comprise one or more wheels, runners, caterpillar tracks or the like. The depth holder 13 can be suspended from a depth holder frame 16, which can be movable relative to the main frame 10. For example, the depth holder frame 16 can be hinged relative to the main frame 10. The depth holder frame 16 can also be movable relative to the main frame 10 by means of a depth holder link 17, which can be connected to the main frame 10 by a first joint 22 and to the depth holder frame 16 by a second joint 23.

The agricultural implement can further comprise one or more transport wheel frames 14, which can be movable relative to the main frame 10. For example, the transport wheel frame 14 can be connected to the main frame 10 by a joint 21. The joints 21, 22, 23 can be configured such that they allow rotation about an axis but prevent translation, for example as butt-hinge joints or pivot joints.

The transport wheel frame 14 can be connected to the depth holder frame 16 by at least one, preferably two rods 15. The rods 15 can be configured and dimensioned to absorb both compressive loads and tensile loads. The rods 15 can be fastened to the transport wheel frame 14 by a respective first joint 19a and to the depth holder frame 17 by a respective second joint 19b. At least one of these joints 19a, 19b can be configured such that it allows two-dimensional or three-dimensional rotation but prevents translation, for example as a ball joint. The use of this type of joint allows the side sections of the agricultural implement 1 to be collapsed into a transport position, as shown in Fig. 3.

Fig. 4 shows a schematic diagram of the agricultural implement 1' according to one embodiment. According to this embodiment, the transport wheel frame 14 is rotated in the same directions Rl, R2 as the depth holder frame 16', i.e. lowering of the transport wheels also means a lowering of the depth holder 13. In this embodiment, the construction of the main frame 10', the lengths of the rods 15' and of the lever arms 16' , and the positioning of the joints 21' , 19a' , 19b' and 23' are chosen such that a suitable transmission ratio between the motions of the transport wheels and of the depth holder is achieved.

Fig. 5 shows a schematic diagram of an agricultural implement 1' ' according to another embodiment. In this embodiment, the transport wheel frame 14 and the depth holder frame 16 are rotated in opposite directions Rl, R2' , i.e. lowering of the transport wheels means raising of the depth holder 13. In this embodiment also, the construction of the main frame 10'', the lengths of the rods 15'' and of the lever arms 16'', and the positioning of the joints 21", 19a", 19b" and 23" are chosen such that a suitable transmission ratio between the motions of the transport wheels and of the depth holder is achieved.

An actuator 18, for example in the form of one or more hydraulic cylinders, can be arranged to act between the main frame 10 and the transport wheel frame 14. The actuator can act between joints 24, 25 placed on the main frame and the transport wheel frame (Figs. 4, 5) . The joints 24, 25 can be of the butt-hinge or pivot joint type.

As a result of hydraulic fluid being fed to the actuator 18, its piston is pushed out and effects clockwise rotation of the transport wheel frame 14 about its joint 21. The rod 15, 15', 15" will then effect corresponding (or opposite - Fig. 5) rotation of the depth holder arm 16, 16', 16'' about the joint 23, 23' , 23' ' , whereupon the height position of the depth holder 13 is also adjusted.

It will be appreciated that the actuator can instead be arranged to act against the depth holder frame, and that the transport wheel frame, correspondingly, can be arranged to move with or counter to the motion of the depth holder frame.

By draining the hydraulic fluid from the actuator 18 (and/or feeding hydraulic fluid to a second chamber) , the transport wheels, and also the depth holder, are raised into a position shown in Fig. 2, in which the depth holder, but not the transport wheels, has contact with the ground, which can correspond to a maximum working depth.

It will be appreciated that by adjusting the actuator 18, the height position of the depth holder 13 (and at the same time the height position of the transport wheel) can be changed without the transport wheel touching the ground. The working depth can thus be controlled. By further feeding of hydraulic fluid to the actuator 18, the working depth is reduced to the point where the transport wheel touches the ground, which can happen when the working depth is zero. Further feeding raises the depth holder and the tools 12 from the ground, for example into a field transport position, i.e. a position which is utilized when turning on a headland.

It will be appreciated that the geometry of the agricultural implement should be configured such that the transport wheel starts to take up the load from the depth holder only once the tools have been drawn up out of the soil. In other words, the tools, when transport wheel and depth holder are at the same height position, can be substantially elevated from the ground.

According to one embodiment, further raising can be achieved, for example into a transport position. Alternatively, the transport position can be achieved by separate raising of the tools, for example by the raising of side sections, as shown in Fig. 3.

Figs. 6a-b and 7a-b show an alternative embodiment of an agricultural implement 1' ' ' , which comprises a main frame 10, as well as two side section frames 31a, 31b which are rotatable relative to the main frame about a respective joint 33a, 33b, which joint produces a rotational axis extending substantially horizontally in the principal direction of travel of the agricultural implement 1' ' ' . The agricultural implement can thus be collapsed into a transport position (as in Fig. 3), in which the side sections 31a, 31b are substantially vertically oriented.

In the shown embodiment, the side section frames

31a, 31b have a respective depth holder 13a, 13b, which is suspended from a respective depth holder frame 16a, 16b. Between the respective side section frame 31a, 31b and the respective depth holder frame 16a, 16b is arranged a respective actuator 32a, 32b, which can be a hydraulic actuator or possibly a pneumatic actuator.

The actuator 32a, 32b can be hydraulically (or pneumatically) connected to the actuator 18 and be arranged as a slave actuator to the actuator 18. Thus activation of the actuator 18 also effects activation of the actuator 32a, 32b.

The actuators 18, 32a, 32b can be configured and chosen such that a desired transmission ratio is achieved, for example as illustrated in Figs. 7a and 7b, in which the stroke length of the actuator 18 is substantially greater than the stroke length of the actuator 32a.

Alternatively, the actuator 32a and/or the actuator 32b would be arranged as master actuator and the actuator 18 as the slave actuator.

It will be appreciated that one or more further actuators 34 can be arranged to control the position of the side sections 31a, 31b relative to the main frame.