Abstract: A sowing machine has row units, where each of the row units includes tillage tools and a hydraulic cylinder which applies a coulter pressure upon the tillage tools that is adjustable by a pressure valve. Further, a sensor arrangement includes at least two sensors for producing an electrical signal in connection with a total pressure acting upon the tillage tools of each row unit. In addition, an open-loop or closed-loop control device is connected to the pressure valves and the sensor arrangement and configured to adjust the coulter pressure of each row unit individually and to adapt it on the basis of the electrical signals of the sensor arrangement. In order to create a sowing machine with individual coulter pressure control that is inexpensive to manufacture, a reduced number of sensors is advantageously employed by using a functional relationship.

Abstract: The invention relates to a hydraulic circuit for colter pressure and blower rotational speed adjustment at an agricultural spreading machine, with a first line region, which is configured to be connected to at least one colter pressure adjustment cylinder and to specify a hydraulic pressure to the colter pressure adjustment cylinder, a second line region which is configured to be connected to a hydraulically drivable blower and to specify a hydraulic pressure to the blower, and a hydraulic valve for adjusting the hydraulic pressure in the first line region and the hydraulic pressure in the second line region.

Abstract: The invention relates to a hydraulic circuit for colter pressure adjustment at an agricultural spreading machine, with a first line region which is configured to be connected to a first colter pressure adjustment cylinder and to specify a hydraulic pressure to the first colter pressure adjustment cylinder, a first pressure limitation valve which is configured to limit the hydraulic pressure in the first line region to a first maximum pressure, a second line region which is configured to be connected to a second colter pressure adjustment cylinder and to specify a hydraulic pressure to the second colter pressure adjustment cylinder, and a second pressure limitation valve which is configured to limit the hydraulic pressure in the second line region to a second maximum pressure.

Abstract: A sowing machine has row units, where each of the row units includes tillage tools and a hydraulic cylinder which applies a coulter pressure upon the tillage tools that is adjustable by a pressure valve. Further, a sensor arrangement includes at least two sensors for producing an electrical signal in connection with a total pressure acting upon the tillage tools of each row unit. In addition, an open-loop or closed-loop control device is connected to the pressure valves and the sensor arrangement and configured to adjust the coulter pressure of each row unit individually and to adapt it on the basis of the electrical signals of the sensor arrangement. In order to create a sowing machine with individual coulter pressure control that is inexpensive to manufacture, a reduced number of sensors is advantageously employed by using a functional relationship.