Division of Information Technology, Engineering and the Environment
Agricultural Machinery Research Design Centre
Agricultural Machinery Research Design Centre
An Hydraulic Depth Control Mechanism for Seeding and Tillage Applications.
The problem of depth control of agricultural implements has to date had little research effort directed toward it. Increased cost pressures currently facing the Australian farmer (due to depressed grain prices on the world market, high interest rates and on farm costs) and the successful breeding of high yielding dwarf varieties of grain (intolerant to deep sowing) have lead to an increased awareness of the necessity for accurate depth control.
In an endeavour to overcome the problem of poor depth control a depth control system was designed, manufactured and tested. A mechanism incorporating tyne assemblies mounted on a parallel linkage mechanism and featuring hydraulic depth control is the central component of the depth control system. A number of these mechanisms mounted on an implement would provide accurate control of tillage and seeding depth.
The performance of the mechanism was evaluated under simulated field conditions using the Tillage Test Track at the South Australian Institute of Technology. The performance of the mechanism in the untilled soil condition resulted in reasonable depth control. In tilled soil conditions, the low draft forces resulted in mechanism behaviour which was very insensitive and user unfriendly with large variations in working depth common. Although the mechanisms performance did not meet the original specifications it did serve to demonstrate the feasibility of using draft force to control tillage and seeding depth.
On the basis of the results obtained further research and development
(with the aim of commercial development) appears to be justified. The
commercial future of the depth control mechanism lies in implements
specifically designed to use a number of the mechanisms. This would
result in a new generation of tillage and seeding machinery which would
provide a cost effective means of ensuring accurate depth control and
increasing the productivity of Australian farms.
